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1
Beyond 3GLTE/EPC (SAE )
LTE: Long Term EvolutionSAE: System Architecture
Evolution (Now EPC: Enhanced Packed
Core)
2
Agenda
Quick overview 3GPP / 3G Technologies
Overview 4G Technologies
LTE/SAE Architecture
LTE/SAE Interfaces
LTE/SAE Protocols
3
What is 3GPP? 3GPP stands for 3rd Generation Partnership Project It is a partnership of 6 regional SDOs (Standards Development Organizations)
These SDOs take 3GPP specifications and transpose them to regional standards
ITU references the regional standards
Japan
USA
4
3G Technologies Overview
3GPP : UMTS Phase 1 (3GPP release 5) : HSDPA service, upto 10 Mbps Phase 2 : Uplink high-speed data, high-speed access for TDD Phase 3 : Capacity Improvements in UL and DL, above 10 Mbps
3GPP2 : cdma2000 CDMA2000 1x : upto 144 Kbps CDMA2000 1xEV-DO
high rate packet data (HRPD) service, separate carrier for data only upto 2.4 Mbps on the downlink, 153 Kbps on the uplink
CDMA2000 1xEV-DV All-IP architecture for radio access and core network, upto 3 Mbps
Next-Generation Cellular System (in about 2010) 100 Mbps full-mobility wide area coverage 1 Gbps low-mobility local area coverage
5
Introduction To 4G
4G is term of Fourth-Generation Communications System. End-to-end IP solution where voice, data and streamed multimedia
can be served to users on an "Anytime, Anywhere" basis at higher data rates than previous generations.
Support interactive multimedia, voice, video, wireless internet and other broadband services.
Limitation to meet expectations of applications like multimedia, full motion video, wireless teleconferencing
6
High speed, high capacity and low cost per bit.
Global mobility, service portability, scalable mobile networks.
Seamless switching, variety of services based on Quality of Service (QoS) requirements
Better scheduling and call admission control techniques.
Ad hoc networks and multi-hop networks.
- cont’d
7
Why Move Towards 4G?
Wider Bandwidth Difficult to move and interoperate due to different standards
hampering global mobility and service portability Primarily Cellular (WAN) with distinct LANs’; need a new
integrated network Limitations in applying recent advances in spectrally more
efficient modulation schemes Need all all digital network to fully utilize IP and converged video
and data
8
Where Do We Want to Go?
Seamless Roaming Integrated “standard” Networks Mobile Intelligent Internet Onwards to (Ultra) Wideband Wireless IP
Networks
9
-cont’d HSPA is the first progressive step toward delivering ‘triple
play’ (telephony, broadband and TV) in a mobile broadband environment
Likely acceptance of mobile broadband and mobile triple play will raise the need for evolved UMTS; therefore it is vital that operators ensure the long term evolution of 3G infrastructure
The 3GPP RAN Long Term Evolution (LTE) task force was created at end 2004, notably considering the ‘Super 3G’ proposal of NTT DoCoMo
The proposed RAN architecture, placing increasing functionality within the NodeB, will be based on IP routing with existing 3G spectrum, providing speeds up to 100 Mbps by using channel – transmission bandwidth between 1.25MHz and 20MHz
3GPP Evolved UMTS specifications should target availability of commercial products around 2008-2010
10
4G Networks Advances
Seamless mobility (roaming) Roam freely from one standard to another Integrate different modes of wireless communications – indoor networks
(e.g., wireless LANs and Bluetooth); cellular signals; radio and TV; satellite communications
100 Mb/se full mobility (wide area); 1 Gbit/s low mobility (local area) IP-based communications systems for integrated voice, data, and video
IP RAN Open unified standards Stream Control Transmission Protocol (SCTP)
Successor to “SS7”; replacement for TCP Maintain several data streams within a single connection
Service Location Protocol (SLP) Automatic resource discovery Make all networked resources dynamically configurable through IP-based
service and directory agents
11
3G To 4G Transition
3.5 G Evolved radio Interface IP based core network
4G New Air Interface Very high bit rate services Convergence of Wireline, Wireless, and IP worlds
13
3G Evolution and Vision
3G Evolution Long Term VisionEvolution
3G Beyond 3G
Time
All-IP
Network
Long Term Vision
Time
Present
Network
IP based
MM networkAll-IP
Network
Phase 2
Phase 1
Phase 0 Phase 3
AN first evolution path
CN first evolution path
Evolution PhaseEvolution Phase
15
4G Vision 4G will be a fully IP-based integrated system of
systems and network of networks wired and wireless networks (e.g.: computer, consumer electronics, communication technology…)
Providing 100 Mbit/s and 1 Gbit/s, respectively, in outdoor and indoor environments
End-to-end quality of service High security Offering any kind of services anytime, anywhere Affordable cost and one billing
16
Wireless Access Evolution
BroadbandBroadband
New ServicesNew Services
EfficiencyEfficiency
Broadband
Subscribers
Voice
CoverageCoverage
MobilityMobility
Voice QualityVoice Quality
PortabilityPortability
CapacityCapacity
BroadbandBroadband
Network Network SimplificationSimplification
Cost of Cost of OwnershipOwnership
17
Two Key technologies are evolving to meet the Wireless Broadband Requirements
802.11n(smart antennas)802.11Mesh extns.
Lo
cal A
rea
Fix
ed
Wid
e A
rea
Mo
bile
Co
vera
ge/
Mo
bili
ty
Met
ro A
rea
No
mad
ic
802.16(Fixed LOS)
802.16a/d(Fixed NLOS)
802.11b/a/g
Mobile Industry
Fixed Wireless Industry
4G Air Interfaces
Data Rates (kbps)100,000 +
3GPP2CDMA
2000-1X
HRPDA1x
EVDO
1x EVDV Rel. C
1x EVDVRel. D
GSM UMTS HSPAGPRS EDGE LTE 3GPP
MOBILE BROADBAND
DSL ExperienceDial Up
Higher Data Rate / Lower Cost per Bit
802.16e(Mobile WIMAX)
18
Intro To LTEstudied and developed in 3GPP is an evolution of 3G into an evolved radio
access referred to as the Long-Term Evolution (LTE) and an evolved packet access core network in the System Architecture Evolution (SAE).
4G Technology Broadband Wireless Triple Play (Voice, Video & Data) All IP-Network Integrated Technology True high-speed mobile data Full-motion HD video anywhere Stream any content Mobile peer2peer & Web 2.0 Common core for all access technology Centralized IMS services Common applications across access technology Spectrum flexibility 1.25 to 20MHz for re-use in existing spectrum End-2-End QoS Allow prioritization of different class of service All-IP vision: base stations become an access router
19
3GPP Long Term Evolution (LTE)
3GPP (LTE) is Adopting: OFDMA in DL with 64QAM All IP e2e Network Channel BWs up to 20 MHz Both TDD and FDD profiles Flexible Access Network Advanced Antenna Technologies UL: Single-Carrier FDMA (SC-FDMA), (64QAM optional) 4 x Increased Spectral Efficiency, 10 x Users Per Cell
20
LTE (Long Term Evaluation)
Supply Bandwidths from 1.25-20 MHz
Subcarriers spacing 15kHz.
Bit rate up to 100Mbps, and by using MIMO the speed should reach 350Mbps !
SC-FDMA for U.L. & OFDM for D.L.
21
3G Evolution LTE / SAE Radio Side (LTE – Long Term Evolution)
Improvements in spectral efficiency, user throughput, latency Simplification of the radio network Efficient support of packet based services: MBMS, IMS, etc. Evolved-UTRA
The air interface, Evolved-UTRA (E-UTRA) is used by UMTS operators in deploying their own wireless networks. The E-UTRA system uses OFDMA for the downlink and Single Carrier FDMA for the uplink. It uses MIMO with a maximum of four antennas per station.
Network Side (SAE – System Architecture Evolution)
Improvement in latency, capacity, throughput Simplification of the core network Optimization for IP traffic and services Simplified support and handover to non-3GPP access technologies
22
+ True high-speed mobile data
+ Full-motion HD video anywhere
+ Stream any content
+ Mobile peer2peer & Web 2.0
+ Quadruple play
+ Faster email access
+ Instantaneous web pages
EDGE
EVDO-AHSDPA
LTEFiber
ADSL-2+
ADSL
Mbps
40-100MbpsFiber like speed on mobile
Faster
23
+ Spectral efficiencyBetter utilization of spectrum available
+ Low frequency, Advanced Receivers and Smart AntennaFor improved coverage and reduced cost of ownership
+ Increased CapacityMuch higher user and sector throughput for lower individual cost service delivery
+ Simpler RAN, IP Core & Centralized service deliveryFewer nodes & interfaces (Node-B/RNC/Gateway) One Network & IMS for all access technologies
+ Connect to legacy coresExisting network asset investment protection
+ 3GPP/2 Market tractionEconomy of scale
LTE VoIP cost*
UMTS rel.99 voice call cost$
10%
3GPP subscribers 85% market share
Predicted LTE VoIP voice call cost* - Sound Partners Limited Research
Lower Cost
24
10-5msec latencyHighly Responsive Multimedia
+ Improved user experience
+ Fast VoIP call set-up
+ Instantaneous web pages
+ Streaming fast buffering
+ Online mobile gamingEDGE
EVDO-AHSDPA
LTEFiber
ADSL-2+
ADSL
More Responsive
25
LTE Key agreements 2 main issues have been investigated:
The physical layer The access network internal architecture
Physical layer Downlink based on OFDMA
OFDMA offers improved spectral efficiency, capacity etc Uplink based on SC-FDMA
SC-FDMA is technically similar to OFDMA but is better suited for uplink from hand-held devices
(battery power considerations) For both FDD and TDD modes
(User Equipment to support both) With Similar framing + an option for TD SCDMA
framing also Access Network consideration
For the access network it was agreed to get rid of the RNC which minimized the number of nodes
26
Expectations for 3GPP Evolution End User
Ubiquitous mobile access Easy access to applications & services Appropriate quality at reasonable cost Long battery life Enhanced security
Network Operators QoS and security management Flexibility in network configuration Reduced cost of equipment Maximized usage and sharing capabilities Single authentication
Manufacturer/Application Developer Reduced cost of equipment Access to global market Programmable platforms
27
3G Long Term Evolution RAN
Long term target peak data rates Up to 100 Mbps in full mobility, wide area deployments Up to 1 Gbps in low mobility, local area deployments
Long term spectral efficiency target: In a single (isolated) cell, up to 5-10 bps/Hz In a multi-cellular case, up to 2-3 bps/Hz
Reaching the peak data rate targets by gradual evolution of existing 3GPP (UTRAN) and alternate access
means (e.g. WLAN) by new access techniques
CN Seamless integrated network Broadband and multiple bearer service capability Interworking between 3GPP mobile network and other networks Ad-hoc networking approach
28
3GPP LTE and SAE
Goal of LTE Significantly increased peak data rates, scaled linearly
according to spectrum allocation Targets:
Instantaneous downlink peak data rate of 100Mbit/s in a 20MHz downlink spectrum (i.e. 5 bit/s/Hz)
Instantaneous uplink peak data rate of 50Mbit/s in a 20MHz uplink spectrum (i.e. 2.5 bit/s/Hz)
29
3GPP LTE and SAE
In the Core network: The LTE effort to meet the technical and performance
requirements requires a reduction in the number of network nodes involved in data processing and transport. This has resulted in new System Architecture Evolution (SAE) which becomes the core network architecture of 3GPP's future LTE wireless communication standard.
Services are provided by IMS core One node to provide the SGSN and GGSN functionality Mobility Management Entity and User Plan Entity might be
collocated in the Access Gateway entity but this is still an open point
Full architecture provided with two nodes IMS
30
3GPP LTE and SAE
SAE focus is on: enhancement of Packet Switched technology to
cope with rapid growth in IP traffic higher data rates lower latency packet optimised system
through fully IP network simplified network architecture distributed control
32
LTE Architecture
eNB eNB
eNB
MME/UPE MME/UPE
S1
X2
X2
X2
EPC
E-UTRAN
Evolved Packet Core
MME/UPE = Mobility Management Entity/User Plane Entity
eNB = eNodeB
33
eUTRAN (LTE) interfacesLogical view
MME/GW
S1-CS1-C S1-C
X2 X2
eNode BeNode B eNode B
EvolvedPacketCore
EvolvedUTRAN
34
Key LTE radio access features
LTE radio access Downlink: OFDM Uplink: SC-FDMA
Advanced antenna solutions
Diversity Beam-forming Multi-layer transmission (MIMO)
Spectrum flexibility Flexible bandwidth New and existing bands Duplex flexibility: FDD and TDD
20 MHz1.4 MHz
TX TX
SC-FDMA
OFDMA
35
3GPP LTE and SAE
System Architecture Evolution Looking at the implications for the overall
architecture resulting from: 3GPP’s (Radio Access Network) LTE work 3GPP All-IP Network specification (TS22.978) the need to support mobility between
heterogeneous access networks
36
3GPP LTE and SAE SAE architecture
MME – Mobility Management Entity UPE – User Plane EntityAS – Access SystemRed indicates new functional element / interface
37
SAE Componenets Serving GPRS Support Node (SGSN) - to provide connections
for GERAN and UTRAN Networks Serving Gateway - to terminate the interface toward the 3GPP
radio-access networks PDN Gateway - to control IP data services like routing,
addressing, policy enforcing and providing access to non-3GPP access networks
Mobility Management Entity (MME) - to manage control plane context, authentication and authorization
User Plane Entity (UPE) - to manage user contexts, ciphering, packet routing and forwarding, and mobility
3GPP anchor - to manage mobility for 2G/3G and LTE systems SAE anchor - to manage mobility for non 3GPP RATs Policy Control and Charging Rules Function (PCRF) - to
manage Quality of Service (QoS) aspects
38
Interfaces
S1-MME: The S1-MME interface provides the control plane protocol between the LTE RAN and MME.
S1-U: The S1-U interface provides a per bearer user plane tunneling between the LTE RAN and Serving GW. It contains support for path switching during handover between eNodeBs. S1-U is based on the GTP-U protocol that is also used for Iu user plane in the Rel-7 architecture.
S3: The S3 interface enables user and bearer information exchange for inter 3GPP access network mobility in idle and/or active state. It is based on the GTP protocol and the Gn interface as defined between SGSNs.
S4: The S4 interface provides the user plane with related control and mobility support between GPRS Core and the 3GPP Anchor function of Serving GW and is based on the GTP protocol and the Gn reference point as defined between SGSN and GGSN.
S5: The S5 interface provides user plane tunneling and tunnel management between Serving GW and PDN GW. It is used for Serving GW relocation due to UE mobility, and if the Serving GW needs to connect to a non-collocated PDN GW for the required PDN connectivity. There are two variants of the S5 interface, one based on the GTP protocol and one IETF variant based on Proxy Mobile IPv6 (PMIP).
39
Interfaces contd. S6a: The S6a interface enables transfer of subscription and authentication
data for authenticating/authorizing user access to the evolved system (AAA interface) between MME and HSS.
S7: The S7 interface provides transfer of (QoS) policy and charging rules from PCRF to Policy and Charging Enforcement Function (PCEF) in the PDN GW. The interface is based on the Gx interface.
S8a: The S8a interface is the roaming interface in case of roaming with home routed traffic. It provides user plane with related control between the Serving GW in the VPLMN and the PDN GW in the HPLMN. It is based on the GTP protocol and the Gp interface as defined between SGSN and GGSN. S8a is a variant of S5 for the roaming (inter-PLMN) case. There is also an IETF variant of called S8b that is based on Proxy Mobile IPv6 (PMIP).
S10: The S10 interface between MMEs provides MME relocation and MME to MME information transfer.
S11: The S11 interface is the interface between MME and Serving GW. SGi: The SGi interface is the interface between the PDN GW and the
packet data network. Packet data network may be an operator external public or private packet data network or an intra operator packet data network, e.g. for provision of IMS services. This interface corresponds to Gi and Wi interfaces and support any 3GPP or non-3GPP access.
40
OFDM Characteristics High peak-to-average power levels Preservation of orthogonally in severe multi-path Efficient FFT based receiver structures Enables efficient TX and RX diversity Adaptive antenna arrays without joint equalization Support for adaptive modulation by sub-carrier Frequency diversity Robust against narrow-band interference Efficient for simulcasting Variable/dynamic bandwidth Used for highest speed applications Supports dynamic packet access
41
Ch.1
Ch.2 Ch.3 Ch.4 Ch.5 Ch.6 Ch.7 Ch.8 Ch.9 Ch.10
Ch.3 Ch.5 Ch.7 Ch.9
Ch.2 Ch.4 Ch.6 Ch.8 Ch.10
Ch.1
Conventional multicarrier techniques
Orthogonal multicarrier techniques OFDM
50% bandwidth saving
frequency
frequency
A
B
Traditional FDM Signal and OFDM
42
OFDMA Symbol Structure
The OFDMA symbol structure consists of three types of sub-carriers as shown in Figure.
Data sub-carriers for data transmission Pilot sub-carriers for estimation and synchronization purposes Null sub-carriers for no transmission: DC carriers
44
Duplexing Technique FDD/TDD
Multiple Access Method TDMA/OFDMA
OFDM Symbols allocated by TDMA Sub-Carriers within an OFDM Symbol allocated by OFDMA
DiversityFrequency, Time, Code (CPE and BS), Space Time Coding, Antenna Array
45
FDD (Frequency Division Duplexing ) Uses One Frequency for the DownLink, and a Second Frequency for the UpLink.
TDD (time Division Duplexing) Uses the same frequency for the Downlink and the Uplink.
In any configuration the access method is OFDMA/TDMA .
F2 - Frequency band
UpLink
F1 - Frequency band
DownLink
FDD
F1 - Frequency band
UpLink
F1 - Frequency band
DownLink
TDD
Duplexing - Principles
47
LTE/SAE Technology Life Cycle• LTE (Long Term Evolution), a 3GPP concept, defines a long-term evolution for radio
access technology.
• SAE (System Architecture Evolution), a 3GPP concept, defines a long-term evolution for
core network.
• LTE and SAE have been approached independently, however by enhancing each
other, they are no more separable today.
2006 2007 2009 2010 20152008
Initial study completed
Standard aimed
to be finalized
Trial start
Commercial deployment start
Year
Mass deployment
Standard aimed
to be developed
Source: 3GPP &UMTS-Forum
48
3G- R’993G- R’99HSPAHSPA
HSPA EvolutionHSPA Evolution
LTELTE
2002 2005 2008/2009 2009
384 kbps 3.6 Mbps 21/28/42 Mbps ~150 MbpsPeak rate
2007
7/14 Mbps
Mobile broadband speed evolution
LTE EvolutionLTE Evolution
2013
1 Gbps
Target
Other CDMA Mobile WiMAX GSM/GPRS/EDGE WCDMA HSPA LTE
2006 2007 2008 2009 2010 2011 2012 20130
1 000
2 000
3 000
4 000
5 000
6 000
7 000
Reported Subscriptions (million)
49
Wireless Broadband Main vendor strategies
Vendor HSPA LTEEV-DO
UMB
Mobile
WiMAX
Support Focus
Cooperation with Huawei
Sold to ALU 2006