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Thesis No. MEE09:41
APSEN ANALYSIS FOR BEYOND 3G WIRELESS
NETWORKS
Muhammad Qadeer Muhammad Humran Khan
This thesis is presented as part of Degree of Master of Science in Electrical Engineering
Blekinge Institute of Technology June 2009
Blekinge Institute of Technology School of Engineering Department of Telecommunication Systems Supervisor: Richard Norlin Examiner: Richard Norlin
I
ABSTRACT
The beyond 3G official IEEE name for next generation of wireless technology, some
people also called it as 4G (fourth-generation) mobile communication systems. Beyond
3G will be used largely to contain not only cellular telephone systems but also several
types of broadband wireless access communication systems, have been attracting much
interest in the mobile communication field. A new age has begun for telecommunication
industry. Over the past decade wireless industry has grown at a remarkable pace,
consequently level of technology development goes beyond the level of customer desire.
Application flexibility and being highly dynamic will be the main features of beyond 3G
services of interest to users. Being there all these emerging technologies in one cellular
network has opened the work of designing and optimization of the networks to be viewed
from a different perspective. APSEN analysis for Beyond 3G wireless networks has been
discussed. “AP” stands for application layer, analysis of services and applications. “SE”
stands for session layer, analysis of session management protocol and “N” for network
layer, analysis for network protocols. The main purpose of our research is to focus on the
challenges offered at APSEN for beyond 3G wireless network. There are a lot of research
challenges in each of the different layers but focus will be on APSEN. The objective is to
take a look at and familiarize with some of the major challenges offered at APSEN for
beyond 3G wireless network. Qualitative approach has been used which will help us to
collect wide range of information and enhance our knowledge by analyzing the
perspectives of different researchers.
Keywords: B3G, 4G, APSEN, QoS, OSI, MIND, PUD, NMT, AMPS, VAS, GPRS, EDGE, UMTS, 3GPP, SDP, SAP, MCHO, Mobility management, TLDN, Mobile IP.
II
Acknowledgements
All admires to Almighty ALLAH, the cherisher and the sustainer of the universe, the
most gracious and the most merciful, who bestowed us with health and abilities to
complete this project successfully.
We would like to express our deepest gratitude to our project supervisor Richard Norlin
for his patience and guidance during the thesis work. He is always a source of inspiration
for us. His encouragement and support never faltered.
Our special gratitude and acknowledgments are there for our parents for their eternal
moral support and encouragements.
Muhammad Qadeer & Muhammad Humran Khan
Karlskrona, June 2009.
III
TABLE OF CONTENTS
APSEN analysis for Beyond 3G Wireless Networks ..................................................................................................................................... Abstract……….… ............................................................................................................................................................................................ II Acknowledgement ……………………. ....................................................................................................................................................... III List of Figures……………………. .............................................................................................................................................................. VII Chapter 1 (introduction) .................................................................................................................................................................................. 1 1.1 Our Work…. ................................................................................................................................................................................................. 1 1.1.1 Application Layer ...................................................................................................................................................................................... 2 1.1.2 Session Layer ............................................................................................................................................................................................. 2 1.1.3 Network Layer ........................................................................................................................................................................................... 2 1.2 Motivation.. . ................................................................................................................................................................................................. 4 1.3 Goals / Objectives ......................................................................................................................................................................................... 4 1.4 Contributions................................................................................................................................................................................................. 5 1.5 Scope of our thesis........................................................................................................................................................................................ 5 1.6 Our approach to present the work................................................................................................................................................................ 5 1.7 Organization .…………………………………………………………………………………………………………………………..6 Chapter 2 (Background History) ................................................................................................................................................................... 7 2.1 First Generation Systems (1G) .................................................................................................................................................................... 7 2.1.1 NMTs (Nordic Mobile Telephones) ........................................................................................................................................................ 7 2.1.2 AMPs (Advance Mobile Phone System) ................................................................................................................................................ 7 2.2 Second Generation System (2G) ................................................................................................................................................................. 8 2.2.1 The GSM (Global System for mobile communication) network .......................................................................................................... 9 2.2.2 VAS (Value added services) .................................................................................................................................................................... 9 2.2.3 GPRS (General Packet Radio Services).................................................................................................................................................. 9 2.2.4 EDGE (Enhanced Data rates in GSM Environment) ........................................................................................................................... 10 2.3 Third Generation System (3G) .................................................................................................................................................................. 10 2.3.1 Universal Mobile Telecommunications Service (UMTS) .................................................................................................................... 10 2.3.2 3GPP (Third Generation Partnership Project) ....................................................................................................................................... 10 2.3.3 3GPP2 (Third Generation Partnership Project 2) .................................................................................................................................. 11 2.4 Beyond Third Generation/towards fourth generation (4G)...................................................................................................................... 12 2.4.1 Why 4G? Motivations to have 4G .......................................................................................................................................................... 12 2.4.2 Some new features in 4G ........................................................................................................................................................................ 13 2.4.3 4G some potential applications............................................................................................................................................................... 13 2.4.4 General Requirements for Beyond 3G System...................................................................................................................................... 15 2.5 Different technology Comparisons............................................................................................................................................................ 17 Chapter 3 (AP of APSEN) ............................................................................................................................................................................. 18 3.1 OSI Model… ............................................................................................................................................................................................... 18 3.2 Different Layers Interaction towards 4G .................................................................................................................................................. 19 3.2.1 The Physical Layer towards 4G.............................................................................................................................................................. 20 3.2.2 Data Link Layer towards 4G .................................................................................................................................................................. 20
IV
3.2.3 The Network Layer towards 4G ............................................................................................................................................................. 20 3.2.4 The Transport Layer towards 4G ........................................................................................................................................................... 20 3.2.5 The Session Layer towards 4G ............................................................................................................................................................... 21 3.2.6 The Presentation Layer towards 4G ....................................................................................................................................................... 21 3.2.7 The Application Layer towards 4G ........................................................................................................................................................ 21 3.3 Major Issues Containing Layers ................................................................................................................................................................ 21 3.3.1 Quality of Service Perceived By the User ............................................................................................................................................. 23 3.3.1.1 Higher Bit Rates ................................................................................................................................................................................... 24 3.3.1.2 Lower Communication Latency .......................................................................................................................................................... 25 3.3.1.3 Provision of Service Everywhere ........................................................................................................................................................ 25 3.3.1.4 The Need to Provide QoS for Applications ........................................................................................................................................ 25 3.3.1.5 Variation of Time in QoS Support ...................................................................................................................................................... 26 3.3.1.5.1 The control mechanism of the QoS .................................................................................................................................................. 26 3.3.1.5.2 The management mechanism of the QoS ........................................................................................................................................ 26 3.3.1.6 Protocols used by the Application Level QoS .................................................................................................................................... 27 3.3.2 Creating Flexible Services ...................................................................................................................................................................... 27 3.3.2.1 Service Creation Approach .................................................................................................................................................................. 27 3.3.2.2 Scenarios of Mobile IP Based Network Development (MIND) ....................................................................................................... 28 3.3.2.2.1 Leisure Time Scenario of MIND ..................................................................................................................................................... 28 3.3.2.2.2 Nomadic Worker Scenario of MIND ............................................................................................................................................... 28 3.3.2.2.3 Medical Care Scenario of MIND ..................................................................................................................................................... 29 3.3.4 Advancement and Vision ........................................................................................................................................................................ 29 3.3.2.4 User Expectations ................................................................................................................................................................................. 29 3.3.3 Adjustable Applications/Services ........................................................................................................................................................... 30 3.3.3.1 Required Applications in 4G Networks .............................................................................................................................................. 31 3.3.3.2 Capabilities of Services in 4G Networks ............................................................................................................................................ 32 3.3.3.2.1 First Level of Service Capabilities ................................................................................................................................................... 33 3.3.3.2.2 Second Level of Service Capabilities .............................................................................................................................................. 34 3.3.3.2.3 Third Level of Service Capabilities ................................................................................................................................................. 34 3.3.3.2.3 Networking Which Is User Based .................................................................................................................................................... 34 Chapter 4 (SE of APSEN) .............................................................................................................................................................................. 36 4.1 Overview …. ............................................................................................................................................................................................... 36 4.1.1 Establishment of Connection Phase ....................................................................................................................................................... 37 4.1.2 Transmission of Data Phase .................................................................................................................................................................... 37 4.1.3 Releasing the Connection phase ............................................................................................................................................................. 37 4.2 Management of User Profile ...................................................................................................................................................................... 38 4.2.1 User Terminal .......................................................................................................................................................................................... 38 4.2.2 Configuration of Networks ..................................................................................................................................................................... 39 4.2.3 Accessing the Service.............................................................................................................................................................................. 39 4.2.4 Representation of the User in the System .............................................................................................................................................. 39 4.2.5 Profile Manager ....................................................................................................................................................................................... 40 4.3 Process of Service Discovery..................................................................................................................................................................... 41 4.3.1 Mobile Based Service Discovery (MBSD) ............................................................................................................................................ 42 4.3.1.1 Identification of the Services ............................................................................................................................................................... 43 4.3.1.2 Performance of the MBSD .................................................................................................................................................................. 43 4.3.2 Service Discovery by Session Announcement Protocol (SAP)............................................................................................................ 44 4.4 Parameters of End-to-End QoS Negotiation ............................................................................................................................................. 44 4.4.1 End-To-End Signaling ............................................................................................................................................................................ 45 CHAPTER 5 (N of APSEN) .......................................................................................................................................................................... 46 5.1 Mobility management on different layers … ............................................................................................................................................ 46 5.1.1 Mobility at Physical layer ....................................................................................................................................................................... 47 5.1.2 Mobility at Link Layer ............................................................................................................................................................................ 47 5.1.3 Mobility at network layer........................................................................................................................................................................ 47 5.1.4 Mobility at transport layer ...................................................................................................................................................................... 47 5.1.5 Mobility at Session layer......................................................................................................................................................................... 48
V
5.1.6 Mobility at Presentation layer ................................................................................................................................................................. 48 5.1.7 Mobility at Application layer.................................................................................................................................................................. 48 5.2 Mobility management challenges .............................................................................................................................................................. 48 5.2.1 Access Technologies ............................................................................................................................................................................... 49 5.2.2 Different Network Architectures and Protocols .................................................................................................................................... 49 5.2.3 Mobile users service demands ................................................................................................................................................................ 49 5.3 Why Mobility Management at Network Layer? ....................................................................................................................................... 49 5.4 Mobility Management ................................................................................................................................................................................ 49 5.4.1 Mobility management overview ............................................................................................................................................................. 50 5.4.1.1 Location Management.......................................................................................................................................................................... 50 5.4.1.1.1 Location management main issues................................................................................................................................................... 51 5.4.1.2 Handover (Handoff) Management ...................................................................................................................................................... 51 5.4.1.2.1 Different types of handoff ................................................................................................................................................................ 52 5.4.2 Mobility Management in Mobile Networks .......................................................................................................................................... 53 5.4.2.1 Location management in mobile networks ......................................................................................................................................... 53 5.4.2.2 Call Delivery in mobile networks ....................................................................................................................................................... 54 5.4.3 Fourth Generation mobile networks: Location registration and call delivery ..................................................................................... 55 5.4.3.1 Databases architectural design............................................................................................................................................................. 56 5.4.3.1.1 Architectural design for centralized databases ................................................................................................................................ 56 5.4.3.1.1.1 Dynamic Hierarchical database architecture ................................................................................................................................ 56 5.4.3.1.1.2 Strategies for multiple-copy location information ....................................................................................................................... 56 5.4.3.1.1.3 Pointer forwarding and Local Anchoring ..................................................................................................................................... 57 5.4.3.1.2 Architectural design for distributed databases ................................................................................................................................ 58 5.4.3.1.2.1 Fully distributed registration scheme ............................................................................................................................................ 58 5.4.3.1.2.2 Database Hierarchy ........................................................................................................................................................................ 58 5.4.3.1.2.3 Partitioning scheme ........................................................................................................................................................................ 58 5.4.4 Mobile IP and mobility management ..................................................................................................................................................... 58 5.4.4.1 Location Registration in Mobile IP ..................................................................................................................................................... 59 5.4.4.2 IPv6 modifications ............................................................................................................................................................................... 60 5.4.4.2.1 Movement detection in IPv6............................................................................................................................................................. 60 5.4.4.2.1.1 Advertisement lifetime .................................................................................................................................................................. 61 5.4.4.2.1.2 Network Prefix method.................................................................................................................................................................. 61 5.5 QoS support for Network layer.................................................................................................................................................................. 61 5.5.1 Categorization of QoS ............................................................................................................................................................................. 61 5.6 All the existing fixed and mobile networks Internetworking .................................................................................................................. 62 5.6.1 Signal Processing and Radio Interface ................................................................................................................................................... 62 5.6.2 Issues related to Core Network and Radio Access Network ................................................................................................................ 63 5.6.3 Software Architecture, Applications and Services ................................................................................................................................ 63 5.6.4 Technologies ............................................................................................................................................................................................ 63 CHAPTER 6 (Conclusions) ........................................................................................................................................................................... 65 6.1 Conclusions … ............................................................................................................................................................................................ 65 6.2 Future Work. ............................................................................................................................................................................................... 66 Appendices…….. ............................................................................................................................................................................................. 67 References…….. .............................................................................................................................................................................................. 72
VI
LIST OF FIGURES
1.1 APSEN cut pieces ........................................................................................................................................................................ 2 1.2 APSEN structure .......................................................................................................................................................................... 3 2.1 First Generation Cellular Networks ............................................................................................................................................ 8 2.2 Global System for mobile Communication systems architecture ............................................................................................. 9 2.3 UMTS 3G Network Architecture… .......................................................................................................................................... 11 2.4 Beyond 3rd Generation Network Architecture .......................................................................................................................... 14 2.5 Seamles Communication ........................................................................................................................................................... 24 3.1 OSI model Layers View............................................................................................................................................................. 19 3.2 B3G/4G Mobile Communication .............................................................................................................................................. 19 3.3 QoS percieved by the user ......................................................................................................................................................... 24 3.4 Adaptive Applications................................................................................................................................................................ 31 3.5 Model for services and Applications in 4G .............................................................................................................................. 33 4.1 User Profile Views ..................................................................................................................................................................... 41 4.2 Scenario of MBSD ..................................................................................................................................................................... 42 4.3 MBSD View for Client and server ............................................................................................................................................ 43 4.4 End-to-End QoS ......................................................................................................................................................................... 45 5.1 Location Management Process Components ............................................................................................................................ 50 5.2 Handoff Management Components .......................................................................................................................................... 52 5.3 Location management procedures in mobile networks............................................................................................................ 54 5.4 Procedural steps for call delivery .............................................................................................................................................. 55 5.5 Pointer Forwarding Strategy ...................................................................................................................................................... 57 5.6 Architectural Design of Mobile IP ............................................................................................................................................ 59 5.7 Location Registration in the Mobile IP ..................................................................................................................................... 60
VII
CHAPTER 1
Introduction
PSEN is basically a subpart of OSI (Open System interconnection) reference
model by ITU. The fundamental idea of OSI was to break up various parts that
makeup a communication system. The system has been divided into different layers each
layer is responsible for specific functions assigned to it. Although the OSI reference
model was initially developed for communications between computers but now it is being
used widely in the field of telecommunication especially in mobile communications [1].
Mobile communication system [2] is distinctively known by generations. Generation
according to the scientific definition is a “stage or period of sequential technological
developments and innovations” [3]. The mobile communication system with consecutive
generations has been based on the radio interface technologies and also on the distinct
sequence of generations 1G → 2G → 3G → 3.5G → 4G. The beyond 3G (B3G = 3.5G =
fourth generation) mobile communication systems are likely to answer the remaining
issues of 3G (third generation) systems and to present a wide variety of latest services,
from high quality voice → High definition video → High data rate wireless channels. All
these advancements will create a lot of challenges. Within the same session, user with
relatively a large range of mobility will be able to reconnect the different networks
seamlessly [4].
1.1 Our Work
The title of our thesis is “APSEN analysis for beyond 3G wireless network”. After
careful consideration we chose this topic because it covers wide range of research areas
hidden within APSEN for beyond 3G wireless networks. We would like to explain the
A
1
term used in our proposed title as shown in the Fig. 1.1 APSEN is the combination of
three words
Fig. 1.1 APSEN cut pieces
Fig 1.2 shows our research areas to be considered in our thesis. Although there are a lot
of research challenges on each of the different layers [5] but we will focus on APSEN
and try to explore in the following areas:
1.1.1 Application layer
• QoS perceived by the user
• Creating flexible Services
• Adjustable Applications/Services
• Networking which is User-based
1.1.2 Session Layer
• Management of User profiles
• Process of Service discovery
• Parameters for End-to-end QoS negotiation
1.1.3 Network Layer
• Network layer mobility management
• QoS support for Network layer
• All the existing fixed and mobile networks Internetworking
2
Figure: 1.2 APSEN Structure
3
1.2 Motivation
Fourth Generation will be able to answer the remaining challenging questions found in
the 3rd generation. The number of mobile users unexpectedly has been raised with a great
pace and will go on even faster in the near future. All the research work weather it is on
academic level or on the industry level, is mainly have been driven due to the number of
growing mobile subscribers and their requirements of high speed connection with
mobility. Flexible and well dynamic applications are the main features of fourth
generation. All these things have opened the new horizons for research to be viewed from
different perspectives. We will view the APSEN perspective while migrating from 3G
cellular network to beyond 3G or 4G network.
According to Ericsson [6] the users which use the mobile broadband services will be
capable to use the 4G high speed network in the near future by signing the agreement
between Ericsson and Telia Sonera. It will be begin in 2010 and will offer the real time
performance, users will enjoy the high quality television program on their mobile phones,
laptop or computers from anyplace on the network. So it’s the ideal time to research and
have some technological knowledge before implementation.
1.3 Goals/Objectives
The goal of this thesis is to provide some brief insight into the APSEN. The
objectives of this research are to investigate the following challenging questions while
migrating from third generation mobile network to fourth generation network.
• What is the Quality of service parameters which will come up to the expectations
of the user while going from 3G mobile systems to 4G mobile systems?
• Will the users be able to create the flexible services in fourth generation systems?
• Does the 4G provide the feasibility of adaptive service/application?
• Will the requirements for user based networking be met in 4G?
• While dealing with bunch of Applications/Services, How the service discovery
will be done in 4G?
4
• How the user profiles management will be done in 4G?
• As end-to-end QoS is the necessary part of every service, how 4G will cater with
this issue?
• How 4G will look to handle the mobility management issue?
• What kind of QoS support will be provided in the 4G?
• How 4G will provide the Internetworking of all the existing fixed and mobile
networks?
1.4 Contributions
The fourth generation networks already govern the research work carried out at academic
as well as at industry level. There are a lot of milestones to achieve to realize this concept
to become reality [7]. This thesis introduces the concept of APSEN which is relatively a
new one in the research areas. This will open and initiate the research which has some
limitations in 3G related to APSEN and how these will be solved while going into the
4G.
1.5 Scope of our thesis
The scope of the thesis is very important because wireless network includes a lot of
wireless technologies. To consider all possible aspects will be very difficult and need
more time and effort than a normal thesis length. So we focus our thesis only on to the
cellular networks i.e. beyond 3G cellular networks. For further narrowing our study, we
will focus on the APSEN. Some research challenges will be investigate as mentioned in
section 1.3.
1.6 Our approach to present the work
Our approach to present the work according to Strauss and Corbin in 1990 [8] that the
methods for qualitative study can be used for any phenomena for better understanding,
for something still to explore. In other words, these methods can also be used to get new
viewpoints on things which have already been much explored or to get detailed
understanding which quantitatively difficult to explain. So the research on different OSI
model layers has already been explored and problems will be explored further in this 5
thesis with the focus on APSEN for beyond 3G wireless networks to provide appropriate
solutions. In the first phase of this thesis the documents on the mobile communication
systems especially regarding generations will be studied in details so that we gain the
technical understanding of the research area. While dealing with the different OSI layers,
our main research will be done on APSEN. Our literature study might include internet
sources, libraries, official records, letters, newspaper, reports and also the data which has
been published in the review of the text. After getting good understanding, in second
phase we will relate our researched data to provide better solutions of the challenges
faced in APSEN when moving from 3G to 4G in Wireless networks.
1.7 Organization
The structure of the report is as follows:
In first chapter we will discuss about the introduction of our master thesis, its
motivations, goals/objectives, contributions, scope of the thesis and in the end our
approach to present the work. Second chapter will introduce the background history of
the cellular networks i.e. 1G, 2G, 3G and beyond 3G. Third chapter will discuss the “AP”
of the APSEN. Fourth chapter will discuss the “SE” of the APSEN. Fifth chapter will
discuss the “N” of APSEN. Chapter six will conclude and will discuss the future work.
6
CHAPTER 2
Background History
HE brief history and mobile service evolution from the first generation (1G) to
fourth generation (4G) will be discussed in this section.
2.1 First Generation System (1G)
The first-generation mobile system was based on the analogue transmission techniques
started in 1980. There was no organization for the development of technical standards for
the system over the world as well as in the Europe.
2.1.1 NMTs (Nordic Mobile Telephones)
Installed in the Nordic countries and TACS which stands for Total Access
communication System deployed in UK and Ireland [1].
2.1.2 AMPS (Advance Mobile Phone System)
First initiated by US was based on FDMA technology and allow users to connect within
the country for voice calls only. Efficient use of the frequency spectrum and roaming was
impossible in these systems. In 1G cellular network, the MSC not only maintains the
database information but also controls the network management functions like billing call
handling and processing. It also keeps all mobile associated handoff. The MSC with the
help of wired trunk and a tandem switch [9] is connected to the PSTN. To connect the
MSC to one another dedicated signaling (i.e. SS7 network) is used to exchange the call
signaling information, location information and authentication information. As shown in
T
7
the figure for first generation mobile network in which we have the mobile devices, base
stations, and mobile switching centers.
Figure: 2.1 First generation cellular networks [9]
2.2 Second Generation System (2G)
European commission in the mid of 1980s, started a number of activities in
communication area involving mobile communications to be more flexible and more
open. In result of this ETSI (European Telecommunication Standard Institute) was
established which was accountable for development of the specifications for the GSM
(Global system for Mobile Communication). This system has Base Station Subsystem
which contains Base transceiver Station BTS and Base Station Controller BSC and
Network Switching Subsystem. There are MSC (Mobile Switching Center), Visitor
Location Register (VLR), Home Location Register (HLR), Authentication center (AC)
and Equipment Identity Register (EIR).
8
Figure 2.2: Global System for mobile communication system architecture [10]
2.2.1 The GSM (Global System for mobile communication) network
Provide the primary services like speech and data services up to 9.6kbps, etc. and also
give the extension to the dedicated telephony network. GSM has step by step developed
to encounter the requirements of data traffic and other services which were not pondered
in the primary network.
2.2.2 VAS (Value added services)
Value added services were established in the GSM such as VMS (Voice Mail System)
and SMSC (Short Message Service Center). SMSC was really proven to be very
important feature of GSM and was very successful commercially. Intelligent services
(IN) also played a good role in the GSM favor together with operators to design a whole
class of new services. Pre-paid services and fraud management are the outcome of the
intelligent service.
2.2.3 GPRS (General Packet Radio Services)
Serving GPRS (SGSN) and Gateway GPRS (GGSN) was added to the living GSM
system to encounter the demand for sending data on the air-interface. Furthermore, it
includes the IP routers, domain name servers DNS, and firewall servers. This also
9
provides the right to use Internet and the bit rate attaining 150 kbps in the best
circumstances.
2.2.4 EDGE (Enhanced Data rates in GSM Environment)
EDGE was established to increase the data rate by means of the more complicated coding
techniques over the Internet which really increases the data rate up to 384 kbps.
2.3 Third Generation System (3G)
Although Enhanced Data rates in GSM Environment make sure the high-volume
movement of data, but packet movement on the air-interface acts similar to a circuit
switch call which reduce the efficiency due to circuit switch setting. Also the network
developing standards were not similar for different parts of the world. So there was a
need to have network which offers services which are technology platform independent
and also which have the same standards for designing the networks. The solution comes
in terms of new generation i.e. third generation 3G.
2.3.1 Universal Mobile Telecommunications Service (UMTS)
Also known as (UTRA) Universal Terrestrial Radio Access which is the European
standard for 3G and it is derived by the ETSI. This is based on the WCDMA (wideband
code division multiple access) [10].
2.3.2 3GPP (Third Generation Partnership Project)
Third Generation Partnership Project was established to carry on work on the technical
specifications during 1998 [11]. Five main standardization areas have been defined for
UMTS.
• RAN (Radio Access Network) also known as Universal Terrestrial Radio
Access Network (UTRAN) [10]
• CN (Core Network)
• Terminals
10
• GSM EDGE Radio Access Network (GERAN) [12], System Aspects and
Services
2.3.3 3GPP2 (Third Generation Partnership Project 2)
Third Generation Partnership Project 2 was established to consider the technical areas of
CDMA-2000 which is a member of International Mobile Telecommunications-2000
(IMT-2000) is the name given by ITU-T for 3G [10, 11]. IMT-2000 is the network access
and radio specification which describe a number of technology platform or techniques
which fulfill overall objectives of the specification.
Figure 2.3: UMTS 3G Network Architecture [11]
11
IMT-2000 is a specification which enables the mobile and high speed data services to
utilize one or a number of radio channels among fixed network platforms for carrying the
services for:
• High quality services
• Standards which are globally accepted
• Services for IMT-2000 and some other fixed networks for compatibility
• Common frequency band for global use
• Small size terminal for worldwide usage
• Roaming capability worldwide
• Enhanced spectrum efficiency
• Services and terminals for multimedia applications
• Evolution flexibility for next generation wireless systems
• High data rates for pedestrian 384 Mbps, for fixed environment 2Mbps, for
vehicular traffic 144 Mbps. [10]
2.4 Beyond Third Generation/towards fourth generation (4G)
The term B3G stands for beyond third generation, is the official IEEE name [13] for the
next stage of wireless technology, some people also call it fourth generation or 4G. Now
4G has a number of definitions, 4G is the next generation of the wireless network in the
near future. In other words, it is simply a beginning in academic research and
development labs to analyze the limitations and issues of third generation facing
problems for deployment, performance and throughput. 4G is also a logical framework
and a discussion point to deal with the future requirements of a global high speed
wireless network that will connect seamlessly to a wire line backbone network [14].
2.4.1 Why 4G? Motivations to have 4G
If 3rd Generation systems are working well then we might have a question that why we
need 4G systems? There are two reasons to answer this question, one is considerable
increase in overall number of subscribers and other is enormous demand of new data
12
services either interactive or non-interactive. For cellular communication these two
factors are enough for a big bottle neck. Although 3G claims the data rates about 2Mbps
but the actual data rates are slower than this in the congested networks and in the packed
areas. Furthermore the data rates also rely on the user activity while on moving or in the
steady state and location, whether it is indoor or outdoor as projected, in future the
multimedia services will take part in diffident role and definitely govern the cellular
traffic as an alternative of voice. In this situation the existing 1G and 2G systems will be
overcrowded and have no space to exist. Also increasing data rates guides to higher
bandwidth necessity. So there is a need to build up a common standard for a system for
the cellular industry that can compensate almost all the confinements in the last cellular
technologies [15].
2.4.2 Some new features in 4G
The following are some new features of 4G cellular networks:
• Network which is entirely packet-switched
• The entire network will be consist of digital elements
• Higher network security
• Provides higher bandwidth for multimedia services at relatively low cost [16]
2.4.3 4G some potential applications
Virtual Presence: 4G cellular system will provides the always-on connections for mobile
users to keep people intact with the business events and activities whether they are onsite
or offsite.
Virtual navigation: The graphical information of streets, buildings and structural
characteristics of a large metropolitan area will be stored in the remote databases and
required information will be accessed in the moving vehicle through a client program to
visualize the environment to the fore.
Tele-medicine: For example in case of traffic accident, a paramedic assisting the patient
at remote location will be able to access the records i.e. X-rays etc. and through video
13
conferencing a remotely located surgeon can help him. So in this way surgeon can review
the information given by the paramedic remotely.
Crisis Management Applications: In case of natural catastrophe where the whole
communication structure is destroyed, it may take days or even weeks to reestablish the
communications in case of wireline infrastructure. 4G will provide a quick solution to
restore the underlying communication even internet and video services could be
established in a matter of hours.
Distance learning: 4G system will provide online education which could be affordable in
terms of cost [17].
Tele-geoprocessing: It a combination of (GIS) geographical information systems, (GPS)
global positioning systems and high-capacity wireless mobile systems will produce a new
type of application as tele-geoprocessing. The tele-geoprocessing will make it possible
for the public safety society to work with wireless specific applications for everyday
procedures as well as for crisis management systems [17, 18].
Figure 2.4: Beyond 3rd Generation network architecture [19]
14
2.4.4 General Requirements for Beyond 3G System
These are some of the following characteristics that can be expected in beyond 3G
systems.
All-in-one: All-in-one solution means B3G should support any combination of radio
access networks. The next generation mobile systems are expected to have wireless Local
area networks, Wireless metropolitan area networks, Wireless personal area networks and
various air interfaces like 3G, 3.5G and 4G air interfaces [20].
Seamless handoff procedures: Seamless procedures occur in such a way that the user
does not recognize the quality change during and after the handoff, so B3G should
support the seamless handoff procedures between same or different network technologies
and between different administrative domain or within the same domain [21].
Figure 2.5: Seamless communication [22]
15
Quality of Service requirement: Quality of Service requirement within B3G services
should be distributed through the most suitable radio access network. To manage the QoS
for multimedia services a policy-based framework has been introduced which will
facilitate the association between application layer and IP layer for event and resource
management respectively. End-to-end QoS contains the following four components
Radio access network, the core network, the air interface and the service level
agreements. End-to-end QoS depends on the different mechanisms which are used in the
IP QoS running with combination of one another and modified for each segment in the
end-to-end path [23].
Mobility Management: Mobility management is the major challenge for the
telecommunication networks; need to draw some mechanisms to reduce the effects [24]
due to the movement of the object around the networks. The key purpose of mobile
communication system [25] is to give the user the liberty of selection to choose its
appropriate communication service at any time. To allow the convergence of the wire line
and wireless communication system, the IP protocol will be used as a universal and
common network layer to connect the heterogeneous network access technologies. When
there will be a choice to access more than one technology then there should be an
optimized decision making algorithm this selection in 4G. There is a need for such a
framework which should be flexible enough for multimedia services which is one of the
main features of the 4G. There should be an architecture which supports the mobility
between different access technologies. 4G should support the mobility prediction
techniques which predict the exact location of the terminal to take as the proactive
procedures for secure seamless handover.
Multimedia Service Support for 4G systems: Multimedia Service Support for 4G
systems required to support not only services for telecommunication but also multimedia
and data services as well. For this commitment high data rate services will be present
with good system consistency and low per bit cost for communication. Service providers
should plan customized and personal services to accommodate the different user demands
16
and simultaneous use of multiple integrated services at any time from any service
provider [26].
2.5 Different technology Comparisons
Table 1: Short technological comparisons [22]
Technology Start
Date
Complete
Date Standard Services Bandwidth
Access
Method
Core
Network
1G 1970 1984 TACS,
AMPS,NMT
Analog
voice,
synchronous
data to 9.6
kbps
1.9 kbps FDMA PSTN
2G 1980 1991
CDMA,
TDMA,
GSM, PDC
Digital voice,
short
messages
14.4 kbps TDMA,
CDMA PSTN
2.5G 1985 1999
GPRS,
EDGE,
1xRTT
Higher
capability
packetized
data
384 kbps TDMA
CDMA
PSTN,
Packet
network
3G 1990 2002 WCDMA,
CDMA2000
Higher
capability,
broadband
data up to
2Mbps
2 Mbps CDMA Packet
Network
4G 2000 2010-12? only one
Standard
Higher
capability,
totally IP
based,
Hundreds of
Mb data for
multimedia
services
200 Mbps CDMA? Internet
17
CHAPTER 3
AP of APSEN
HIS part of our thesis concern with the major area of different layers having issues
when moving from third generation 3G to the fourth generation 4G. APSEN the
main core of our thesis work belongs to layers of OSI Model. Because of this, we would
like to introduce the different layers model called Open System Interface Model (OSI
Model) for the better understanding of layers and challenges associated with them. The
OSI Model consists of seven layers, which are briefly described in this part as follows:
3.1 OSI Model
The OSI model consists of seven layers. This model is said to be a reference tool to
understand the communication between the devices of two or more networks. The
compatibility of the devices should be there to have a good and seamless communication
in the network. The major and basic work was done in late 1970s by the International
Standard Organization (ISO). But later on the work was done by the IEEE on different
layers to standardize the LAN. This model is not the physical framework of standards in
communication [27].
Many of the protocols used for different communication are based on this OSI model.
When dealing with this model, each layer has its own tasks and performance regarding
the transmission and communication of data. Each layer receives data, task or group of
tasks from one layer, performs its function of specific layer and then transmits this to the
other layer. Each layer has its own functionality to work with the given tasks given
during the transmission.
T
18
The seven layers are then further differentiated into two areas depending on their tasks
and works. The upper layers 7, 6 and 5 deals with the applications and software issues but
the lower layers 4,3,2,1 deal with the issues on data transportation [28]. The seven layers
of OSI model are listed below in their top to bottom order as shown in the figure 3.1.
Figure 3.1 OSI Model Layers View [29]
3.2 Different Layers Interaction towards 4G
When moving from 3G to 4G, all layers are concerned for different applications,
communications, services and transmission of data. Each layer performs its role.
Figure 3.2 B3G/4G Mobile Communications [30] 19
3.2.1 The Physical Layer towards 4G
The physical layer deals with different services and applications when moving towards
4G.One of those is Orthogonal Frequency Division Multiplexing (OFDM).The OFDM
will provide clear benefits and good working performance for the physical layer in
4G.The presence of such OFDM on physical layer makes it to work efficiently and to
give valuable results and reduces the complexity at the user end receptions. In 4G, the
physical layer working will be improved by the provision frequency diversity gain by
OFDM.
3.2.2 Data Link Layer towards 4G
The data link layer in 4G will be responsible to collect data and encapsulate it and
transmit it to upper level as doing before. But some new protocols defined for the users
will interact on data link layer in 4G to present and transmit placing information for client
and servers. The OFDM in 4G will also provide the flexibility for Data Link Layer [30].
3.2.3 The Network Layer towards 4G
This is an important layer in our “APSEN” analysis, which is the focus of our thesis. The
main participation of the Network layer is the provision and work with IPv6.The IPv6
will be implemented in 4G wireless networks. There will be lot of wireless and mobile
devices in 4G networks which communicate and transmit data by using IPv6.Because of
the data link layer backhaul infrastructure, there will be no need of Network Address
translation (NAT) for IP version 6 network layer for better and easy solutions. The
network layer will be dealing with the mobility management, supporting the QoS for the
network and the internetworking, communication between the fixed and mobile networks
[31].
3.2.4 The Transport Layer towards 4G
The transportation layer is related and responsible for the transmission and transportation
of data in 4G.Many protocols work with this layer. In 4G, new protocols are defined for
transport layer. Some of the characteristics of those protocols are:
• Flow control 20
• Sequencing
• Acknowledgement
• Error detection
• Connection closing etc.
The transmission, resending of packets will be done in a good way and delay will be
made as minimum as possible [32].
3.2.5 The Session Layer towards 4G
The session layer is also one of the layers in our APSEN analysis. This layer in 4G will
be responsible for session management, services for sessions, protocols for sessions and
many others for good and proper transmission of data. This layer also has some issues
and challenges when moving beyond 3G, which will be elaborated and discusses later.
Session layer mobility is also one of the good features of this layer in 4G.
3.2.6 The Presentation Layer towards 4G
This layer is responsible to take care of the data coming from application layer and to
transmit this on the network. In 4G wireless networks, this layer will be responsible for
proper data reception from application layer, security such as encryption and decryption
and proper presentation of data to and from the application layer.
3.2.7 The Application Layer towards 4G
We are also focusing on this layer in our APSEN analysis beyond 3G. This layer has
much importance while going from beyond 3G wireless networks. The basic interaction
of this layer will be with the user applications and services. To provide good quality, easy
approach, flexible services and understanding to user will be the major priorities of this
application layer in 4G wireless networks.
3.3 Major Issues Containing Layers
When we look for more advancements and enhancements in next generation i.e. B3G,
there are also some challenges and issues along with provision of progressed technology.
These new solutions, technologies, high qualities and better services will definitely be 21
helpful for the users, but before their provision and availability to users the challenges for
them should be solved.
In our thesis, main focus is to look for those challenges, issues, problems which are
obstacles to give the proper meaning of beyond 3G. After a deep and caring study, we
came to know that these issues are regarding users, their management, data transmissions,
quality of service, data bit rate and some more. As in the field of network, OSI reference
model is followed so these challenges and issues belong to different layers of this model.
Some research is also done already on different layers to diagnose the problem and issues
on different layers. So of them are found and some are under research.
While dealing with the layers for better services and good quality in the Beyond 3G or
4G, the issues are mainly concern with the three important layers of the OSI reference
model. These challenges or issues belong to the QoS for user, profile management,
service discovery and traffic classes, maximize spectral efficiency and improve overall
system capacity etc. These three layers are briefly described with some of the issues
related with them as follows:
• Application Layer
• Session Layer
• Network Layer
The layer which has major challenges of the user is the Application layer. This layer is
the closet to the user where he/she interacts directly by using services and applications.
The challenges and issues are
• Issue of the provision of networking known as user based.
• The service of the quality according to the user’s expectations
• There should be flexibility when creating new services, also one of challenge in
4G
• The adaptability of created services and applications is also one of issues for
beyond 3G
22
The second layer having issues and challenges towards 4G networks is the Session Layer.
Many of the major tasks related to users because of different sessions, good quality and
seamless transmission belong to this layer. The major challenges belonging session layer
are
• The dealing and handling of the profiles of the user in a good managed way is
challenge for B3G.
• Working with services for their discovery for appropriate task performance
• The QoS for the end to end user in terms of good communication
The third and major layer responsible for the transmission and communication of the data
is the Network Layer. The interaction between different networks is always made
possible due to this layer. The problems and issues, a network layer contains for 4G
networks are
• The interactions between the fixed or wireless networks and mobile networks in
4G
• To provide a best quality of the network is one of the challenge
• The quality of being mobile and how to manage it on network
• These issues and challenges are discussed in detail below which is the main
participation and contribution in our APSEN analysis beyond 3G thesis.
3.3.1 Quality of Service Perceived By the User
The quality of service can is defined as the properties of the system which are essential to
get the necessary results of an application. One of the major goals of the fourth
generation is to provide the user a service which is of high quality and easily adoptable
by the user. This is a serious issue when moving from 3G to the 4G mobile cellular
networks. User’s satisfaction can be achieved by the provision of services and quality for
his/her needs and requirements. This task was being performed already in 3G networks,
but when talking about the 4G, more demands, high data rates, more graphical data
transmission, high speed audio and video then definitely question raises for the QoS [5].
23
Figure 3.3 Quality of Service Perceived By the User [5]
There are some different parameters necessary to improve the quality of service for the
users. These are listed and described individually as below:
3.3.1.1 Higher Bit Rates
One major difference between the 3G and 4G is the data rate. Support and provision of
high data speed is one of the best features provided in the 4G.This data rate will be at
least at 100Mb/s for the areas where the mobility is of full range and the data rate will be
of 1 GB/s in local areas where the coverage of mobility is low. Need for the bit a rate
varies with usage and applications such as for Audio, video, data, multimedia etc. The
competence optimization for voice services will continue. In 4G the improvements for IP
based networks will make the availability of important data as well as simultaneous voice
and data increasingly. The high quality and high bit rates services, applications and
devices will be needed and used everywhere. Higher data rates services and applications
with good system will be available in 4G for the support of multimedia services. The
availability of the higher bit rates will make the communication seamless.
24
3.3.1.2 Lower Communication Latency
Advanced performance computing on large number of workstations requires low latency
communication in order to proficiently apply parallel languages and distributed
algorithms. The communication latency means the delay in the transformation of the
packet. It can be calculated either one way i.e. from source to destination or in two way
i.e. source to destination and back to the source means round trip. The 4G provides the
better solutions for communication latency making it as low as possible by increasing
bandwidth, speed and by using IPV6. Due to the lower the communication latency,
efficiency of the applications for videos, audios, data and others will be more quick and
better than the third generation networks [33].
3.3.1.3 Provision of Service Everywhere
The limitation of the services in the 3G was a big problem. The provision of services
everywhere is the main goal of the 4G. The main aspect of this section is to make the end
users to get easily access to the services providers any where either that are multimedia
services, data or graphical services etc. The services in the 4G will be made in such a
context that they can automatically be accessed by the home or business users anytime,
anywhere and anything. The information that can be in the user service combinations
may be in the form of the weather, personal preferences, calendars, user profile’s
information, and may be some other services which can be offered to the user of the same
locations or other. The solution of the provision of services everywhere to end user gave
solutions of many problems needed while moving towards beyond 3G. The provision of
QoS constitutes the following components
• QoS Mapping
• Admission Testing
• Resource Reservation Protocol [34]
3.3.1.4 The Need to Provide QoS for Applications
Considering the need for ensuring the consistency and accessibility of the many already
available services and applications, most of them are not considered as good as they
25
should confirm their performance to reside in the networks beyond 3G.The need for the
provision of QoS for the development of the mobile and other wireless systems is the
probable future services and applications, will take into account user needs from their
very beginning. This way of access is necessary to enable the market worth and the
economic success of the systems in the future. Another important feature to provide the
QoS is the, sufficient information provision and context understanding, in terms of
receiving, measuring and analyzing received data and acting accordingly [35].
3.3.1.5 Variation of Time in QoS Support
The importance of the variation of the time in QoS support can be described in such a
way that, distinction between the control of the QoS and the management of the QoS is
differentiated by the different time scales over which they operate. The control of the
QoS performs operations on a quicker time scale than the management of the QoS.
3.3.1.5.1 The control mechanism of the QoS
It works on time scales at or at a very high speed almost close to the speed where media
files transfer. They offer real-time traffic control of flows based on requested levels of
QoS created during the phase of the QoS provision. The basic QoS control mechanism
contains the following:
• Arrangement Of Flow
• Shaping Of Flow
• Policing Of Flow
• Managing Of Flow
• Synchronization of Flow
3.3.1.5.2 The management mechanism of the QoS
The commitment of the resources only is not sufficient for the maintenance of the agreed
level of QoS. The management is also important and necessary, which is done by the
management mechanism of the QoS in different time scales. It works on slower time
scales as compared with the control mechanism of the QoS. The basic QoS management
mechanism contains the following: 26
• Monitoring of QoS
• Accessibility of QoS
• Deprivation of QoS
• Maintenance of QoS
• Scalability of QoS
3.3.1.6 Protocols used by the Application Level QoS
Provision of the protocols at this stage gives more possibilities for QoS negotiation
between the application and the communication components of an application. The
overall QoS negotiation has two impacts i.e. transport services and application protocols.
The supposition of scalable Medias has been made in many application level protocols.
The idea of a new Resource Reservation Protocol is to broadcast multimedia data on
different streams additional control information. Clients can make connections to satisfy
their QoS requirements [36].
3.3.2 Creating Flexible Services
The Fourth Generation 4G will provide a lot of new services and models. The checking
for these services and models to be accommodated in the 4G is also very important. As
the 4G is aimed to provide the services and applications anytime, anywhere with a
seamless connection, and the reception, transmission of the large amount of data, videos,
pictures are also important feature of 4G. So, the services in 4G should be created in a
way that can be easily dealt and used by end user. The application layer interacts directly
to and performs common application services for the application processes. Some of the
services included in the application layer are FTP, DNS, SNMP, Telnet and Remote
Login, Web Browser etc. The creation of the flexible services constitutes the following:
3.3.2.1 Service Creation Approach
The best approach for the creation of services in 4G is to make the services to work and
interoperate easily with applications. These services will be on application level by the
end user. The 4G flexible service creation will provides standardized services such as
virtual terminal, file and job transfer and operations. The services for 4G should be 27
created in a way that they will be felt to be connected anywhere and anytime. These
service creations approach should support all system levels from access methods and
networks to service platforms and services. The approach for services creation should
also be feasible and interoperable for the mobiles applications. The services to be created
should be flexible, adjustable and supportable to the products of 4G. Such approach
should be careful about the change of every day’s life and showing the services and
applications that could be offered.
3.3.2.2 Scenarios of Mobile IP Based Network Development (MIND)
The scenarios for the development and improving the qualities for the services in 4G are
known as Mobile IP Based Network Development (MIND) [36]. These models will
check for new developments, and the adjustments and working of the in the real working
environments for good multimedia services creations and support.
There are three different scenarios for the MIND especially for the wireless and mobile
networks. Each of these scenarios treats and works according to the needs by the users in
different situations. The scenarios are as follows:
3.3.2.2.1 Leisure Time Scenario of MIND
This scenario deals with the needs and requirements of the user who wants to be
connected with the any wireless seamless connectivity e.g. WLAN and also want to
connect with the wireless cellular services such as GPRS etc to utilize the same services
as by wireless and from the same terminals. This kind of scenario contains a user such as
student who uses the college services to connect with the Internet Service Provider (ISP).
3.3.2.2.2 Nomadic Worker Scenario of MIND
This is concerned with the future corporate level workers who are interested to work with
in intranets. This kind of MIND helps and shows to worker that WLAN can also be used
as the part of the intranet facilitating combination with fixed intranets. Such scenario
workers have secure work session with which some other workers are connected using ad
28
hoc networks and some other people can connect through by using different public
networks.
3.3.2.2.3 Medical Care Scenario of MIND
Provision of the QoS on different priorities is dealt in this case. In this medical care
scenario the patient is given a priority. Such kinds of services are provided in special
areas by the rooftop routers.
So, the main things in these scenarios include special support for users and mobility, long
coverage and access range, and providing feasibility for new entrepreneurs planning [37].
3.3.2.3 Advancement and Vision
The vision will be realized of the optimally connected anytime and anywhere through the
all kind of services and networks to be accessed. The views of the 4G will have different
access levels and technologies to be combined with each other to have the solution of the
different network environments and service needs. The advancement for the flexible
service creation will be helpful and used in the local, personal and cellular levels. This
advancement will lead to the easily useable and Internet Protocol IP based networks and
infrastructures. The scalability and mobility are also in the advancement for the flexible
service creation in 4G.The electromagnetic radiations will be reduced with the help of the
Advanced Resource Management. The latest architectures and technologies for the
reconfigurable will be enabled on all layers such as terminals, services and networks.
3.3.2.4 User Expectations
Different users have different expectations and different needs. It can be a good way to
measure the user needs for near future because the needs and demands may vary for a
long run. But on the other hand the services are expected not for long run. So, if the
expectations of the users are considered then new services creation will include the
followings:
• The ways to provide quick and fast service creation and availability of any kind of
services having the facility of self-provisioning, helpful for the user.
29
• Special kind of service creation, which will be helpful for accessing common
services having common service control.
• Make the user more experienced with the services offered to that.
The flexible services for the user expectations can be created in a good way by means of
diversity feature of the services. A special business model will be helpful for the solution
of user expectations even the fixed and mobiles users have different requirements and
expectations.
It’s really good to create new flexible services and provide solutions for the end users, but
on the other hand it’s also necessary to be careful about the cost of new services. These
services should also be financially adoptable. The user expectations and profit of
company are of great value. Today’s user of internet expects the same quality and speed
on the mobile net surfing [38].
3.3.3 Adjustable Applications/Services
There are a lot of applications to be created in 4G to facilitate the end users and also
services to manipulate and work with those applications. The newly created applications
and service should be according to the needs and demands of the users for 4G, but these
services and applications should also easily adaptable by the users. More advanced,
flexible and easily adjustable services will be in more demand to be accepted in 4G.
30
Figure 3.4 Adaptive Applications [5]
3.3.3.1 Required Applications in 4G Networks
The usage of mass scale on a large number of mobile systems and other devices by the
implementation of the write only one time and use anywhere pattern. For this, the way in
which application logic is developed, should be different from the actual working
environment of that created applications. The application created in this way may be
adopted by a large or limited number of users in a big environment like 4G networks, but
on the other hand it can also be very helpful for many other sophisticated environments.
So the creation of the GSCML, an XML markup language, is really helpful for this task
of application creation and to be adopted. The GSCML is classified in three ways, which
are given below.
• A general language for the creation of application logic and adopted openly.
• Hierarchy of the application works in a flexible and extensible way, know as
event model
• A special kind of model known as hierarchical model which is for actions and
works with the services capabilities model and will be discussed in next section.
31
This GSCML helps the application to be initiated from the very beginning level. With the
help of graphical supported applications, the process of innovative application creation
can be simplified and at the same time the end user can create its own applications. The
events are classified into three events in GSCML model, which are named as below.
• Lifecycle events
• Network Events
• User Events
Similarly the actions are also classified in three parts in the hierarchical model of actions
in the GSCML. These three actions are listed below.
• Functionality Invocation Actions
• User Interaction Actions
• State of the local device controlling Actions.
3.3.3.2 Capabilities of Services in 4G Networks
The 4G networks and applications have their own working environments and abilities. So
the model adopted for the 3G for service capabilities is not good enough to be continued
in the 4G. A new model for service capabilities is designed and the design objectives of
this model follow the followings:
• Easily extendable to any capability for any service and anywhere.
• Limited applications can also use this model because of its simplicity.
• Complex service capabilities can be captured.
• Capabilities of backward and forward are also available.
32
Figure 3.5 Model for services and applications in 4G [39]
There exist three levels of the services capabilities. But the model for the services
capabilities in the 4G basically provides the services for first two levels of the hierarchy.
3.3.3.2.1 First Level of Service Capabilities
It deals with the capabilities which are common on basic levels in the 4G.The 4G
applications will use the 4G service capabilities by means of distributed middleware such
as COBRA or Web Services as shown in the figure above. The main functions provided
by this first level are:
• Command’s invocation
• To get registered of events and notifications.
• Events and notifications to be sent.
So the service capabilities offered at first level are named as:
• Common Invocation Capability
• Send Event Capability
• Notification Sending Capability
33
3.3.3.2.2 Second Level of Service Capabilities
The second level of the model serves for capturing the functionalities that belongs to the
common technological areas inside the 4G. The technological area here means the
devices and the services capabilities used by those devices. So when talking about the
4G, this term technologies is divided into three parts as named below.
• Ad Hoc networks and Personal Area Networks
• Local Area Wireless Networks
• Telecommunication Networks for the cells and global coverage.
The first two deals with the user premises and the third interact on the network levels.
The service capabilities for this second level are listed below.
• Display Info Capability
• Get User Info Capability
• Actuator Capability
• Sensor Capability
• Repository Capability
• Remote Connection Capability
• Send Remote Info Capability
3.3.3.2.3 Third Level of Service Capabilities
The third level and successive service capabilities, the model discussed above only
provide the inheritance mechanism. These are used to provide specific services
capabilities. These should not be tended to limitations. The third level of service
capabilities will help to constantly improve the services and applications in 4G networks
[39].
3.3.4 Networking Which Is User Based
Another big challenge for the 4G networks on application layer is the user based
networking. The 4G will provide and support the advanced networks with high data rates,
transmissions of data. The provision of user based networking opens new horizons for
quick and easy communications among the users and networks. It will be a good solution
34
for fixed networks, wireless or cellular networks. The main fields which are responsible
for good user based networking constitutes the receiving and sending data by the user,
high bandwidth, low communication latency, security, seamless communication, easy
and quick response to each others. Users are distributed among the different locations
therefore the session’s times for their communication should also be given more
importance while dealing with the user based networking. As the user directly interacts
on the application layer, the user based networking will provide good solution regarding
efficient traffic for 4G networks. The proper bandwidth distribution also needed for user
based networking, which will be solved for some extent because of the provision of the
higher data rates and seamless communication. The load distribution in term of the
bandwidth should be properly correlated with number of users associated with that
network. The user based networking will surely helpful for the user to accomplish their
tasks and fulfill their needs and requirements.
35
CHAPTER 4
SE of APSEN
HE session initiations, their management for multiple sessions with higher data
rates in 4G networks, multimedia application sessions, management of the user
profile, and the process for the discovery of the service are still the issues of the session
layer in fourth generation networks.
4.1 Overview
The session layer is the fifth layer in the OSI reference model. Sometimes known and
considered as lower layer because it makes possible the provision of function for the
general applications during communications. The consideration as low layer is also
because of it provides reliable transmission of data as sometimes other lower layers are
not good enough for many applications. It provides services to many applications and
sometimes seems more complex to deal and work with applications. The session layer
provides many session services to the applications but on the other hand it is very
complex to deal with some applications. Its complexity can be seen as that it consists of
total 31 kinds of services which are grouped in 12 units, 75 events are for Session
Protocol Machine, the total number of states is 29 and the number of predicates is 72.
This layer is responsible for the interaction between the end user applications of different
systems. Establishment, maintenance and the termination of logical connections for
mapping one-to-one onto transport connection is done by the session layer. The session
layer during transmission and working provides the half-duplex/full-duplex transmission,
data grouping and recovery. The functionality of the session layer can be described as it
performs it actions in three phases accordingly, establishment of connection, transmission
of the data and third is the releasing that connection. Each of these is described briefly as
below [40].
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36
4.1.1 Establishment of Connection Phase
In this phase, three parties such as the two session users and the provider of the service
are involved. They agree on the parameters which define the characteristics of the
creating session. Their agreement on those parameters is necessary for the creation of
session otherwise no session connection will be created.
4.1.2 Transmission of Data Phase
The next phase after the successful session creation is the transmission of data. Session
creation means the both parties and service provider agreed on parameters which made
the data to flow and transmit for that created session only. Different kind of applications
and services are offered in this phase such as send and receiving data, synchronization
point’s establishment and start or stop some activities if needed.
4.1.3 Releasing the Connection phase
This phase is the last phase of the session and communications. In this phase, the session
is terminated with the agreement of both parties. The whole data and transmission is done
before releasing connection, if once created session is released no more data
transformation and transmission will be possible. Management of different activities and
transmission is also done here. The different kinds of management related with the
session layer are listed below.
• Management of the tokens
• Management of the data to be transferred
• Management of the synchronization
• Management of the activities
• Management of the exception reporting
The session layer is also facing problems in some of the areas when moving towards 4G.
The main fields and the areas in the session layer having issues are listed and discussed
below.
37
4.2 Management of User Profile
The key issue in the session layer for B3G/4G networks, is the management of the user
profile. The complexity and the number of users will be increased to really a very large
scale. The provision of services at good level and management of the individual user
profile is of great value to be considered in 4G networks. This will lead to the satisfaction
and favorable solution for the end user in the complex network of the fourth generation.
The big and complex networks of the next generation should be more reliable and be
secured in a good way. Such kind of solutions will be more appropriate and best effective
if the each user of these networks will be treated and managed individually.
In this section of our thesis we will describe about the management of the user profile for
the networks beyond 3G and 4G networks. Specially, the mobile users in the fourth
generation are of more value while dealing with the individual user during different
sessions of the calls and using other application such as multimedia usage etc.
Management of user profile is dealt at individual level, starting of sessions, during
sessions and at the ending of sessions of the users. The User data and its coordination
with other users are of great importance here specially regarding the privacy and secrecy
of the data of the user. The profile of the mobile user is a bit difficult to manage than the
management of the fixed network based user. Mobile user would like to access the
different services, applications and accessing his/her data on his mobile device. The
security and privacy of his/her data and its management should always be there.
As we are presenting the issues and the problems on session layer and trying to present
the suggested and appropriate solutions for those problems, some of the terms related
with these user profile management issue are listed and briefly described as below. These
are the major components of the user profile management specially when interact with
each other.
4.2.1 User Terminal
The terminal, known as the access device is responsible and deals with the applications
accessed by the user. The request by the users regarding the applications access and
38
utilization, their management is done by this section of the user profile managements.
These applications do not only concern with the user but also interacts with the network
connections, their management for the end user and the terminal itself also. The
configuration and management of this user terminal or access device in advanced way
will be helpful for management of the individual user profile.
4.2.2 Configuration of Networks
User profile management issue could also be resolved by the configuration of the
transport and the access networks. The data or accessed applications start from access
terminal and travels through the networks to reach end user. The configuration according
to the advanced demands and requirements of the user in complex 4G networks will
provide a valuable solution for user profiles.
4.2.3 Accessing the Service
There are some resources or service host which deals with the services needed by the user
terminals inside or outside of the networks. These services are accessed by the access
devices and could be configured accordingly for better service provision and managing
user profile.
4.2.4 Representation of the User in the System
The network services, applications, access devices have their own part for the user profile
management, but the main is the representation of the user in the system. The user is
represented by the Personal User Device PUD. Beside the representation of the user, it
contains the identification, configuration, privacy and secrecy of the user data and other
necessary information for the user profile .This PUD can be implemented by using in
different hardware technologies forms such as flash memories, smart cards, SIM etc. The
authorization and authentication of the user to access different networks, applications and
services are major components of the user profile. The description and limitations for
these are also in the storage device as PUD. Storing of the data and transformation of the
data both should be available by these PUDS for better user profile management .But on
39
the other hand, the PUD only deals and keeps the more important information about the
users and this is the reason the question of security raises here [41].
4.2.5 Profile Manager
The profile manager deals with the user profiles and is responsible for the management of
the profiles and their interactions with other users. With the developing growth of the
users and the networks for fourth generation, the profile manager needs to be updated on
increasingly demands. It is also one of the reasons of the user profile management issue
in the complex big networks of the fourth generation. The usage of the Mobile IP and
IPv6 will also be a probable solution for the proper user profile management in 4G
networks specially the cellular networks. There is another profile manager related with
the PUD and is called the Personal User Device Profile Manager.
Some tasks regarding user profile managements such as the collection of data to interact
with other users, priorities for actions, availability of services and their discovery are
done by some software inside the PUD known as the brokers. The brokers for these
purposes are of two kinds. The brokers for the terminals are responsible for the stored
information in PUD and its communication with access device while the brokers for the
networks deals with outside network for the easy access, friendly and availability of the
services.
Some other aspects and solutions regarding the management of the user profile are
managing the access of the user profile by dealing and handling the requests in
appropriate way with the help of the network or terminal broker [41] depending on
demand. The usage of the manger like data access manager is a better solution for the
issues regarding the management of data and its distribution between the users and the
networks.
40
Figure 4.1 User Profile Views [41]
The components of the user profile are user personal device, subscribed networks, user
devices, user personal data and the subscribed services. Each of these has its own
important role in management of the user profiles. The usage of the device and the
management of the billing and charging are also of important areas for the management
of user profile [41].
4.3 Process of Service Discovery
The provision of the flexible, reliable and cost effective services is also one of the major
goals for the fourth generation especially for the mobile based networks. The discovery
of the services and the process for their discovery is a big challenge while moving
towards 4G. A research on the service discovery shows that the service discovery
protocols helped and used for service discovery in past and will be also used in future.
But the networks especially cellular networks will be IP (Internet Protocol) based
networks and process of the best service discovery by them is problem. This section of
our thesis will present and highlight this issue of the process of service discovery for
session layer and the appropriate solutions for them. The main purposes to resolve this
issue is to provide cost effectiveness and making the efficiency of the services better.
41
Most of the current available service discoveries processes are limited for their areas or to
some extent. But as the major goal of fourth generation networks is to provide services
anywhere anytime, so the current service discovery scenarios are not sufficient for
excellent global access. The service discovery processes for the B3G/4G networks should
be globally adoptable. The formation of the model of the processes of the service
discovery is Mobile Based Service Discovery MBSD [42]. There were some service
discovery scenarios in past which were used for wired networks such as DEAP space [43]
and some were useful for the wireless networks such as Knork Service Discovery
Protocol (SDP) Manager [44].
4.3.1 Mobile Based Service Discovery (MBSD)
This kind of service discovery provides a better solution for advanced mobile networks.
This concept is also better in term of creation of service description which is done
automatically in this model based services rather than the manual creation of the
description of the services. Another advantage of this kind of service creation scenario is
the regeneration of the original models for the other applications related to mobile
networks. The provision of good service discovery is the major goal of this model either
for multiple systems or single, especially in the world of wireless communication. Mobile
applications are focused here. Service discovery methods are defined in a way that
mobile users can access service anywhere and anytime. Description of the service
discovery is generated automatically here by the presence of XML.
Figure 4.2 Scenario of MBSD [42]
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The description, discovery and the composition of the services are the major parts when
discussing about the process of the services discovery. The provision of the services
everywhere will be made possible on the behalf of the description of services. Services
description in MBSD is done by the language XML based Service Description (XSD).
4.3.1.1 Identification of the Services
The services will be identified by mentioning their description, necessary to access them.
The description of the services should be mentioned in a way which will be globally
accessible. Their attributes, classes and functions in language play the basic role in their
identification.
4.3.1.2 Performance of the MBSD:
The working performance of the MBSD can be described in way of interaction between
the two terminals. One is acting as service provider and the other as the requesting
service. The request will be sent by the client and provider would try to facilitate the
client with the requested service by identifying this service in its local registry. If
provider will be unable to provide the requested service then it will ask the client to make
a new service request. If the provider still fails to provide the requested service, then the
request will be broadcasted to get an access of that service [42].
Figure 4.3 MBSD View for Client and Server [42]
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4.3.2 Service Discovery by Session Announcement Protocol (SAP)
Another approach for the discovery of the services in the fourth generation is the
discovery by the Session Announcement Protocol (SAP).A SAP server is used to
announce the services to the users or clients. IP based architecture is used in this scenario
for the multiple service discoveries. The SAP is followed by the Service Description
Protocol SDP which is relevant with the service description. The terms related with the
SDP are the version, name of the session, the owner of the service, id of the session, start
and stop time and other information related with the service [45].
4.4 Parameters of End-to-End QoS Negotiation
A pace towards fourth generation contains a large number of services and applications for
advanced networks. But one of the issues related with session layer is parameters for the
end-to-end quality of service negotiation. The quality of service provision for the
networks and the end user is a problem for the fourth generation networks. As we
presented and discussed the issues of 4G networks in early part of our APSEN analysis,
similarly in this area of the our thesis we will discuss and present and highlight the
problem of parameter of end-to-end QoS negotiation with appropriate solution for this
problem on Session Layer. Like other applications and services in fourth generation,
multimedia streaming applications are of great importance in next generation and the
QoS parameters at end-to-end level for such applications at session layer are as follow
• Delay at end-to-end level
• Change of the end-to-end delay between packets
• Packet Loss
End-to-end delay and the change of the end-to-end delay between the packets, these
issues belong to the available networks and their appropriate communication. These
change with the traffic movements in the networks. As these are related with the
networks, so the appropriate solutions for these will be the provision of the play out and
the jitter buffer. Handoff delay specially the large handoff delay creates a big packets loss
which is not good for the multimedia applications.
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QoS service signaling is also useful for the provision of the messages of negotiation and
QoS querying. QoS framework supported by the network manager and the bandwidth
broker is good and provide the end-to-end QoS in efficient way and without delays [46].
4.4.1 End-To-End Signaling
To resolve the issue of the parameters of the end-to-end QoS negotiation, the end-to-end
signaling is a better solution offered by the control plane in the cellular mobile based
networks. Every host is integrated in the control plane by means of the end-to-end
signaling to get the QoS negotiation.
Figure 4.4 End-To-End QoS [47]
This is helpful for the mobile host to initiate session with the different applications on
servers and to end those sessions in good way. The QoS initiator and the QoS Controller
are two different blocks and mainly dealt in the end-to-end signaling. Different signaling
protocols and different other QoS parameters can be used depending upon the demand of
the networks [47]. 45
CHAPTER 5
N of APSEN
ovement is an important fact of the human life; now people are more and more on
the move with mobile phones, PDA’s, laptops and palmtops, so we can say that
more number of networked devices are also on the move [48]. In internet
protocol suit addresses on the network layer are assigned administratively which
represent a particular sub network of the Internet. IP addresses are used globally and
routing is done at this layer. To maintain these two functions, two different approaches
[49] are used for mobility support as:
Host-specific routes update the routes as each host moves which are called the host-
specific routes. This approach is not feasible today because of the number of users on the
Internet are too much.
Sub network-routes and indirection agents Sub network routes usage and addition of the
indirection agents in the architecture which forwards a mobile node’s packets from home
network to its current location. This approach is used in the current structure of the
Internet Protocol suit and known as the Mobile IP standard.
5.1 Mobility management on different layers
Mobility management in the classical TCP/IP stack has no definite place; a lot of
solutions have been suggested for mobility management at each different layer from
application layer to data link layer. Each solution for mobility management has its own
limitations and strong points. It is very important to understand the meaning of the
mobility associated to a particular layer before suggesting a new solution for mobility at
that layer. The part of this section will give an overview of mobility at different layers of
TCP/IP stack.
M
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5.1.1 Mobility at Physical layer
Actually message is sent out over the network at physical layer; encoding, signaling, data
transmission and reception of data are the basic functions of the physical layer. As
physical layer ensures the transmission and reception of the signals, mobility does not
affect the functions of physical layer whether the device is moving or not. There are other
challenges related to physical layer e.g. multipath fading on the radio channel.
5.1.2 Mobility at Link Layer
This is also known as the link layer handoffs which are of two types, horizontal handoff
and vertical handoff. Horizontal handoff may occur within a single subnet and may be
invisible to higher layers. A handoff between different technologies called the vertical
handoff which is visible to network layer. This layer performs channel scanning,
availability of access technologies, channel condition monitoring, authentication and re-
association in case of mobility [50].
5.1.3 Mobility at network layer
As argued that Link layer only deals with the devices which are directly connected on the
other hand network layer deals with the devices which are remotely connected through
the networks.
Network layer handles the location management and IP addresses which could be
affected by the mobility and also by the inter-subnet and inter-network mobility, change
of interface and due to change in the address. This layer is also taking care of the required
QoS which might be affected by the change in the location and address. Dynamic routing
is another challenge on the network layer, to route the packets dynamically towards the
destination, two solutions have been mentioned in [49].
5.1.4 Mobility at transport layer
Transport layer is affected by the mobility due to packet loss, link capacity and IP address
change. Transport layer mobility management affects the integrity and reliability of end
47
to end delivery of data, re-establishment of connection when they are disconnected,
mobility of sessions and mobility of applications, maintenance of longer connection
states, delays due to reconnection time, transfer rates assessment for new link and for
already connected links are very significant problems on transport layer due to mobility.
Here at this layer the solution for mobility management is the reliable delivery of data,
reconnection, reordering and integrity.
5.1.5 Mobility at Session layer
The main objective of session layer is to keep state information about the parameters
involved in the session and communication state. Mobility may cause the unexpected
killing of application at the transport layer. In case of session layer this layer is free of the
transport and other lower layers. This layer is only be affected by the application
mobility.
5.1.6 Mobility at Presentation layer
In case of mobility, this layer handles the problems like application versions, screen
resolution and codec versions etc. For this a mobility management protocol for
presentation layer is required for new device detection and for modification of data
automatically.
5.1.7 Mobility at Application layer
This layer perceives the modifications happened in the specific layers and provides the
mobility solutions accordingly [50].
5.2 Mobility management challenges
Lot of following research challenges comes due to the integration of different
heterogeneous networks.
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5.2.1 Access Technologies
Next-Generation wireless networks have a lot of diverse heterogeneous networks with
different radio technologies, with different cell sizes from few square meters to hundreds
of square kilometers and having overlapped coverage areas.
5.2.2 Different Network Architectures and Protocols
Next-Generation wireless networks will include the different network architectures and
protocols for routing and mobility management and many others.
5.2.3 Mobile users service demands
Users require diverse services from non real-time applications with less data rate to real
time multimedia applications with high speed given by the different access networks
[51].
5.3 Why Mobility Management at Network Layer?
The main reason to manage the mobility at the network layer is that it is at the base of the
protocol stack model and is the place where mobility support can be useful for every
higher layer, it is useful not only to minimize the reproduction of effort but also to lower
down the level of possible errors or security threats [49].
5.4 Mobility Management
Next Generation (NG) wireless systems are considered to be based on the all IP-based
with the help of heterogeneous access technologies infrastructure. Design of intelligent
mobility management method is one of the research challenges for next-generation all IP-
based wireless networks which really take benefit of IP-based various access
technologies to accomplish the global roaming. NG wireless networks consider
integrating and interoperating the mobility management methods in heterogeneous
networks.
49
Different wireless technologies and networks are there to fulfill wide variety of
requirements of cellular users. Wireless LANs are used to satisfy the high data rate user
requirements, for voice and data services wide-area communications, traditional and
next-generation cellular networks are used, for military and commercial applications
satellite networks have been used for worldwide coverage.
5.4.1 Mobility management overview
Mobility management helps the mobile terminals to allow the users to move while
offering the incoming calls and the calls in the progress. We can view the mobility
management in terms of location management and handoff management.
5.4.1.1 Location Management
It is a process which allows the network to find out the current attachment point of
mobile user for call delivery. The major components of this process have been shown in
the figure 5.3. The location update (location registration) is the stage where mobile
terminal regularly tells the network its updated access point; this enables the network to
have the user authentication and updated user profile.
Figure 5.1 location management process components [52]
The second stage is related to the call delivery, in this stage query is made to the network
for user’s profile location and mobile host’s current location is determined.
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5.4.1.1.1 Location management main issues
Location management main issues are as follows:
• Architectural Design of database
• Messaging procedures design
• Signaling messages transmission issues among various components of network.
• Security issues
• Dynamic updates of the databases
• Delays for queries
• Issues related to the terminal paging methods and delays
5.4.1.2 Handover (Handoff) Management
Handoff management makes the network possible to keep the connection while mobile
terminal carries on moving and changing its network access point. Handoff is the three
stage process, in initiation, the user or network discovers the call for handoff and in new
connection generation where network is responsible to find out the new resources for
handoff and routing. In NCHO (Network controlled handoff) or MAHO (mobile-assisted
handoff), in both cases network creates a new connection for handoff with the help of
new resources and perform some extra routing. In MCHO (Mobile-controlled handoff),
mobile terminal is responsible for new resources on behalf of the network. Flow control
of the data in this stage according to the agreement on the QoS, the old and new
connection path is maintained. All these stages have been shown in the figure 5.2.
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Figure 5.2 Handoff management components [52]
5.4.1.2.1 Different types of handoff
5.4.1.2.2 Intracell handoff It takes place when mobile user moves within the
coverage area (cell) and receives the degraded signal strength below a certain level of
threshold which causes to transfer the user’s calls to new radio frequency with suitable
strength from the same base station (BS).
5.4.1.2.3 Intercell handoff It takes place when mobile user goes into a neighboring
cell and all the connections of the terminal have to transfer to the new base station [52].
5.4.1.2.4 Soft handoff It is the kind of handoff in which source cell channel is
maintained and used for a short time in parallel with the channel in the target cell. So
connection to the target is established before the connection to the source, therefore this
handoff is also called make-before-break.
5.4.1.2.5 Hard handoff It is the kind of handoff in which the channel in the source
is freed first and then the channel in the target cell is occupied, so the connection to the
source is broken before the connection to the target is established. This handoff is also
known as the break-before-make [53].
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5.4.2 Mobility Management in Mobile Networks
As mobile terminals moves around the network coverage area, the network access point
of the mobile terminal (MT) also changes, the location information is not guessed from
ID of the MT thus procedure for the call delivery becomes much more complex. Current
strategies for location management in public land mobile networks (PMLN) require each
MT to register periodically its location with the network. For call delivery network keeps
the location data of every MT in the location databases.
5.4.2.1 Location management in mobile networks
Location registration is done step by step as follows
• When MT enters into the new location area (LA), it transmits a message with
location update to the new BS.
• BS gives this location update to the mobile switching center (MSC) which queries
to its related visitor location register (VLR).
• VLR updates the location of MT, in case the new LA related to the dissimilar
VLR then new VLR finds the address of the home location register (HLR) of the
MT by its MIN (Mobile Identification Number) which is done by the global title
translation. New VLR forwards the location registration to HLR.
• HLR authenticate the MT and update the ID of the associated VLR of MT and
sends the acknowledgement message to the new VLR and cancellation
acknowledge message to the old VLR.
• Old VLR delete the MT record and gives the feedback with cancellation
acknowledgement message to the HLR.
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Figure 5.3 Location management procedures in mobile networks [52]
5.4.2.2 Call Delivery in mobile networks
It includes two main steps, to find the serving VLR of the called MT and to locate the
visiting cell of the called MT. To locate the serving VLR of MT has the following steps:
• Through nearby BS the calling MT forwards a call initiation signal to the serving
MSC of the MT.
• Through global title translation, MSC finds the address of the HLR of called MT
and forwards a location request to the HLR.
• HLR finds out the serving VLR of the called MT and forwards a route message to
the VLR.
• MSC temporarily allocates the (TLDN) temporary local directory number to MT
and forwards the acknowledgement to HLR along with TLDN.
• HLR then moves this data to MSC’s calling MT.
• Calling MSC send request for call setup to called MSC by signaling system seven
(SS7) network.
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These procedural steps allow the network to setup a connection between calling MT and
MSC of the called MT. As there is more than one cell in every LA and every MSC is
related with an LA, so there should be a method to find out the location of the called MT.
Currently paging procedure is used, polling signals are broadcast within the LA to the all
cells of the called MT. MT sends a reply on receiving the polling signals which enables
the MSC to find out the current cell. The drawback of this approach is that as the number
of MTs increases, the number of polling signals increases which uses the extra wireless
bandwidth.
Figure 5.4 Procedural steps for call delivery [52]
5.4.3 Fourth Generation mobile networks: Location registration and call delivery
As location registration is responsible to update the location databases on the bases of
current information and call delivery is responsible to query the databases to find out the
current location of the called MT. When MT is at a long distance from its associated
HLR, then these processes can be considered very costly. As with the passage of time
number of mobile subscriber’s increases and the signaling traffic volume due to the
55
location management is getting very high. Therefore there is a need for mechanisms to
reduce the signaling traffic in 4G mobile networks.
5.4.3.1 Databases architectural design
There are two main research areas, first the enhancement to the current location
management strategies development to improve the IS-41 (or GSM/UMTS) without
changing the basic database architecture. These are based on the centralized database
architectures. Second the new schemes for database architectures for location registration
and call delivery, these schemes are based on the distributed database architectures.
5.4.3.1.1 Architectural design for centralized databases
Centralized database architecture includes the two tier database architecture to remove
the location management cost.
5.4.3.1.1.1 Dynamic Hierarchical database architecture
This architecture is presented by Ho and Akyildtz which is based on the IS-41 standard
and additional database registers DRs (Directory Registers). The basic function of DRs is
to calculate and store the location pointer configuration for MT in the associated service
area. There are three types of location pointers as follows:
• Local pointer tells the current serving MSC of the MT and saved at MT serving
DR.
• Direct remote pointer tells the current serving MSC and saved at remote DR.
• Indirect remote pointer tells the current DR of MT and stored at remote DR.
5.4.3.1.1.2 Strategies for multiple-copy location information
To search for the user location a number of different strategies have been adopted. Per-
user location caching strategy is used to maintain the cache of location information at the
nearest signal transfer point (STP) in which volume of signaling and database access
traffic for locating an MT can be shortened. An entry is made to the cache when MT is
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used through the STP; mapping is done from ID of the MT to its allocated VLR. In case
of another call for MT, STP first looks whether the entry in the cache already there for
that MT. So following possibilities can be considered:
• If there is no cache entry then call delivery scheme is used to search for the MT.
• In case of MT associated with the same VLR, MT can be searchable and a hit is
counted.
• In case where MT transferred to different location that is not under the same
VLR, a miss can be counted and to locate the MT a call delivery scheme is used.
5.4.3.1.1.3 Pointer forwarding and Local Anchoring
These are the strategies in which only the remote end segment of the route is changed.
The main idea of this strategy was to remove the reporting by configuring a pointer from
old to the new VLR. Network first finds out the VLR from the chain of first pointer to the
pointer of current allocated VLR of MT. The pointer chain length is fixed value of K to
minimize the delay to find out the MT.
Figure 5.5 Pointer forwarding strategy [52]
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5.4.3.1.2 Architectural design for distributed databases
This is the advance form of the concept of multiple copy, consists of more than one
databases scattered over the network coverage area.
5.4.3.1.2.1 Fully distributed registration scheme
In this scheme the two level HLR/VLR database is swapped by a number of location
databases with tree organization of root at the top and leaves at the bottom. MTs are
located at the leaves.
5.4.3.1.2.2 Database Hierarchy
This scheme is also very much similar to the fully distributed registration scheme. Here
MTs are not only can be found on the leaves but also at any node of the tree. The tree
root has the database which has the pointers of the MTs.
5.4.3.1.2.3 Partitioning scheme
We can generate the partitions with the help of grouping location servers for MTs which
moves often and location registration is done when MT goes into the partition [52].
5.4.4 Mobile IP and mobility management
Mobile IP is the protocol which is mobility enabled for the internet, which allows the
mobile node (MN) to go from one to another network without any hurdle while the
packets are forwarded. Without changing its IP address the mobile node alters its point of
attachment from one to another subnet. Through HA (Home agent) or FA (foreign agent)
the MN enters into the internet. Here HA is the Internet router on the home network of
MN and FA is the router on the visited network of MN. Correspondent node (CN) is the
node which is on the other side of connection as shown in the figure 5.8.
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Figure 5.6 Architectural Design of Mobile IP [52]
The mobile IP operation can be defined in the following steps:
• Discovery is to locate the updated Internet attachment point by the MN when it
goes from one to the other place.
• Registration is the MN registration with its Home agent
• Routing and the tunneling is the process during which MN accepts the datagrams
while not at home.
5.4.4.1 Location Registration in Mobile IP
Every MN should have an HA while visiting the network which is away from its home.
To track the current IP address, MN registers with its home agent. We have two IP
addresses i.e. one for location and other for identification. Care of address (CoA) is the
address when MN goes to the foreign links and be assigned to it. Mobility binding is the
association between the current CoA and the MNs home address. Every binding has an
associated life time period after which the time for the registration is removed and MN
should be registered itself in this period to continue for this service with the same COA.
MN request and reply messages based on the IPv4 as follows and also shown in the
figure 5.7
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Figure 5.7 Location Registrations in Mobile IP [52]
• MN registers with its Home agent HA with registration request message.
• HA with the help of new lifetime creates the mobility binding for MN
• The most suitable mobile agent response with the reply message with codes to tell
the mobile node the status of its request and gives he lifetime by the HA
5.4.4.2 IPv6 modifications
The following are some modification which is necessary FAs are now replaced by access
points (APs).
5.4.4.2.1 Movement detection in IPv6
When the user in the new LA, the location is updated on the basis of this movement, as
LAs are not used by the Mobile IP to determine the MNs movement in the subnet, a new
feature is used called the APs. The basic movement detection method is used in IPv6 uses
the services of IPv6 neighbor discovery. There are two methods for MN to detect the
movement from one to the other subnet.
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5.4.4.2.1.1 Advertisement lifetime
This lifetime field is used within the ICMP (Internet control message protocol) the router
advertisement part of the agent advertisement is used. Until the lifetime expires, a mobile
node saves the lifetime taken by any advertisement of the agent. In case that MN has lost
the contact with its FA, then MN should try to ask for another agent.
5.4.4.2.1.2 Network Prefix method
In this method to identify the movement, a bit string which includes some of the
preliminary bits of an IP address, is used. An MN can find out that the acknowledged
agent advertisement is from the same subnet as current CoA of MN or not. MN can guess
that it has been moved in case of dissimilar prefixes. If MN currently is using as CoA of
FA then this method can’t be used [52].
5.5 QoS support for Network layer
Lot of development has been done in the field of QoS which is related to the individual
architectural layers and much less progress has been done to explain the large scale
requirements for QoS architectural [54].
5.5.1 Categorization of QoS
4th Generation systems will offer the services like real time and internet-like-services.
There are two categories for real time services, Guaranteed in which pre computed delay
is necessary for the service and Better-than-best-effort includes the properties of
Predictive in which service requires the upper bound on end-to-end delay. Controlled
delay in which services might permit automatic different delays and Controlled load in
which service requires the resources like bandwidth and packet processing. The
parameters like Guaranteed and Controlled load are going to appear in the 4th generation
systems [55].
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5.6 All the existing fixed and mobile networks Internetworking
The internetworking and integration of different access systems on a common platform
which will be totally IP based, is the main feature of the beyond 3rd generation system.
Also to carry a wide range of services on the different access systems will be another
challenge for next generation mobile networks. There are many challenges still to solve
in the areas like
• Issues like signal processing and radio interface
• Issues related to core network and radio access network
• Software architecture, services, applications and compatible technologies
And most important is the global standardization for new schemes for the realization of
the system beyond 3rd generation.
5.6.1 Signal Processing and Radio Interface
Efficient use of frequency resources is the main research area. Many techniques for
physical layer have to be examined as
• The optimization of new promising access systems with the help of enhanced
modulation and channel coding schemes for system performance and spectrum
efficiency.
• Advance detection schemes similar to multi-user detection and cancellation of the
interface.
The algorithms for signal processing to be developed to take the maximum performance
and minimum complexity to handle. Other important problems are the compression
techniques which decreases the required transmitted data rate on the frequency channel.
To support the physical layer issues algorithms are to be improved to solve the issues
like:
• Services for much better usage of the frequency usage and system
performance
• Sharing of the spectrum for different systems
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• To investigate the conditions for coexistence among different radio access
systems
• New antenna logics to develop the link quality and channel capacity.
5.6.2 Issues related to Core Network and Radio Access Network
On the general IP based platform, the internetworking of different access systems with
horizontal and vertical handover through medium access system, raise many challenges
on the core and access network right down to the mobile terminal. According to the
Internet Engineering Task Force (IETF), the routing protocols, mobility management,
MAC schemes and the network management all will be based on the IP. To support real
time and non real time services, the IP methods should be better, comprehensive and
optimized. In IP based mobile networks it is necessary to fulfill the expectations of the
user for QoS mechanism, policing and traffic concepts. For the user’s point of view
security methods are necessary for privacy and security.
5.6.3 Software Architecture, Applications and Services
The main driving force for the future systems will be the services and applications for the
economic success. The applications and services can be Location based services, Internet
access, and video over packet bearer, video gateways, video streaming and video
telephony. The concepts of objects oriented make easy the software reusability and
reduce the number of failures.
5.6.4 Technologies
The high capacity quasi-infinite bandwidth in the wideband IP transmission with
guaranteed QoS is used in the backbone which can be attained by optical links like WDM
and DWDM. The available transmission capacity improved so fast in the optical
communication as compared to the power of the signal processing. The other bottleneck
is the limited throughput capability in the routers which can be avoided with the optical
switching mechanisms in which conversion from optical to electrical signals with the
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associated limited bandwidth can be passed up. In the next wideband systems upper
microwave frequency ranges can be used around from 60 GHz. The software defined
radio will play an important role in the system beyond 3rd generation in which will
provides a flexible programmable signal processing unit and radio frequency unit which
will replace the original access system [56].
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CHAPTER 6
CONCLUSIONS 6.1 Conclusions
Fourth Generation will be able to answer the remaining challenging questions found in
the 3rd generation.
APSEN perspective has been discussed while migrating from 3G cellular network to
beyond 3G or 4G network. APSEN is basically a subpart of OSI (Open System
interconnection) reference model by ITU. The fundamental idea of OSI was to break up
various parts that makeup a communication system.
Major challenges associated with Application layer (AP) for B3G/4G networks have been
highlighted. The provision of higher bandwidth, low communication latency, flexibility
of services and especially QoS for 4G networks are described. Solutions for the
applications and services to run those applications and their easy adoption for 4G
networks are also core part of our work done here. Our proposed and suggested solutions
here will be of great value from user application and future perspectives. Major issues
related with the Session layer (SE) and presentation of their appropriate feasible solutions
have been highlighted. The major issues of session layer in fourth generation such as
service discovery, management of the user’s profile and end-to-end QoS negotiation are
focused here. Seamless, frequent, advance and easily accessible communication is also
another goal of this work done here. Design of intelligent mobility management method
is one of the research challenges for next-generation all IP-based wireless networks
which really take benefit of IP-based various access technologies to accomplish the
global roaming. NG wireless networks consider integrating and interoperating the
mobility management methods in heterogeneous networks.
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6.2 Future Work The fourth generation networks already govern the research work carried out at academic
as well as at industry level. There are a lot of milestones to achieve to realize this concept
to become reality. The number of mobile users unexpectedly has been raised with a great
pace and will go on even faster in the near future. All the research work weather it is on
academic level or on the industry level, is mainly have been driven due to the number of
growing mobile subscribers and their requirements of high speed connection with
mobility. New demands of much higher data rates and their utilization in term of audio
video streaming live conferencing and other multimedia usage will need more
enhancements in future. Some issues will also be there in future regarding end user
quality of service, security of sessions and especially for the mobile and cellular users.
There will be need to explore more on end-to-end QoS and for the high performance of
the multimedia applications.
Next Generation (NG) wireless systems are considered to be based on the all IP-based
with the help of heterogeneous access technologies infrastructure. There is a need of high
level of IP mobility architecture which supports the seamless roaming among these
heterogeneous networks. There should be more simple approach to support the mobility
of users, which implements much more distributed, symmetric solutions for location
management and which are based on Mobile Node connections to the fixed network
routers with additional functions of mobility.
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APPENDICES
67
APPENDIX A Abbreviations and Acronyms
1G 1st Generation
2G 2nd Generations
3G 3rd Generations
B3G Beyond 3rd Generation
4G 4th Generations
OSI Open System interconnection
ISO International Standard Organization
ITU International Telecommunication Union
QoS Quality of Service
NMT Nordic Mobile Telephones
TACS Total Access communication System
AMPS Advance Mobile Phone System
FDMA Frequency Division Multiple Access
ETSI European Telecommunication Standard Institute
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GSM Global system for Mobile Communication
MSC Mobile Switching Center
VLR Visitor Location Register
HLR Home Location Register
AC Authentication center
EIR Equipment Identity Register
VAS Value added services
VMS Voice Mail System
SMSC Short Message Service Center
IN Intelligent services
GPRS General Packet Radio Services
SGSN Serving GPRS
GGSN Gateway GPRS
EDGE Enhanced Data rates in GSM Environment
UMTS Universal Mobile Telecommunications Service
UTRA Universal Terrestrial Radio Access
WCDMA Wideband Code Division Multiple Access
3GPP Third Generation Partnership Project
RAN Radio Access Network
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UTRAN Universal Terrestrial Radio Access Network
CN Core Network
GERAN GSM EDGE Radio Access Network
3GPP2 Third Generation Partnership Project 2
CDMA-2000 International Mobile Telecommunications-2000
IMT-2000 International Mobile Telecommunications-2000
GIS Geographical Information
GPS Global Positioning Systems
OFDM Orthogonal Frequency Division Multiplexing
NAT Network Address translation
E2E End-to-End
MIND Mobile IP Based Network Development
ISP Internet Service Provider
GSCML Service Creation markup language
PUD Personal User Device
SDP Service Discovery Protocol
MBSD Mobile Based Service Discovery
SAP Session Announcement Protocol
NG Next Generation
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NCHO Network controlled handoff
MAHO Mobile-Assisted Handoff
MCHO Mobile-Controlled Handoff
PMLN Public Land Mobile Networks
TLDN Temporary Local Directory Number
SS7 Signaling System Seven
DR Directory Registers
STP Signal Transfer Point
CoA Care of address
ICMP Internet control message protocol
IETF Internet Engineering Task Force
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