Wireless ATM

Miae Woo

2

Outline

• Background

• Concept of WATM

• Reference model, Protocol Stack of WATM

• WATM Development Scenarios

• Research Projects for WATM

• WATM MAC

• WATM LM

3

Background

• Information Super Highway Access to all types of information and media Based on ATM/B-ISDN Technology

• Rapid increase of mobile telecom. service Full capacity of the second generation mobile systems New solution with more capacity and better performance

• Compatibility with the fixed telecom. infra structure Cost-effectiveness

By Miae Woo

favored by the telecommunication industry for advanced high-performance networks, e.g., B-ISDN, as transport mechanism

statistical (asynchronous, on demand) TDM (ATDM, STDM) cell header determines the connection the user data belongs to mixing of different cell-rates is possible

different bit-rates, constant or variable, feasible

interesting for data sources with varying bit-rate:• e.g., guaranteed minimum bit-rate

• additionally bursty traffic if allowed by the network

• ATM cell:

ATM - basic principle

5 48 [byte]

8.2.1

connection identifier, checksum etc.

cell header user data

By Miae Woo

B-ISDN protocol reference model

• 3 dimensional reference model three vertical planes (columns)

• user plane• control plane• management plane

three hierarchical layers• physical layer• ATM layer

– cell multiplexing/demultiplexing

– VPI/VCI translation– cell header generation and

verification – GFC (Generic Flow Control)

• ATM adaptation layer– Provides different service

classes on top of ATM

• Out-of-Band-Signaling: user data is transmitted separately from control information

physical layer

ATM layer

ATM adaptation layer

higherlayers

higherlayers

control plane

layer managem

ent

plane managem

ent

user plane

planes

layers

management plane

8.4.1

6

What is WATM ?

ATM

Wireless ATM

Radio ATM Mobile ATM

ATMSwitch

ATMGatewaySwitch

Database

• Concept of W-ATM : Radio ATM + Mobile ATM

• Radio ATM: Wireless extension of an ATM connections ATM signalling and all virtual connections are transported over the air-

interface Radio link protocol for W-ATM (MAC, DLC)

• Mobile ATM : ATM based fixed network supporting mobility Mobility support (I.e., hand-off, location management, routing etc.)

7

Meaning of WATM

• 3rd-generation of Mobile communication Multimedia-capable integrated wireless network

• Wireless extensions to ATM networks Support of untethered network members

8

System Design Goal of WATM

• Flexible multiservice capability including voice, data and multimedia

• Compatibility with ATM & B-ISDN

• Guaranteed QoS for various service types

• Low terminal cost, power consumption and complexity

• Radio bandwidth efficiency

• Efficient, scalable and cost-effective network architecture

• Compliance with regulatory constraints

9

Comparison of WATM with Other Networks

0.1 100

Fast

Slow

Mobile Speed

1 10 (Mbps)

Fixed

Movable or

Still

Cellular

Cordless

PCS

IMT-2000

Wireless ATM

Wireless LAN (IEEE 802.11)

Fixed Terminal

10

Standardization Bodies for WATM

Europe

• ETSI - RES10 (HIPERLAN) - SMG3/SMG5 (UMTS)• ACTS - Median - Magic WAND• UMTS Forum

ATM ForumWATM

Working Group

International

United States

• ITU-T/R - FPLMTS

• 5 GHz - Supernet(WINForum) - NII (Apple)•2.4 GHz - IEEE 802.11

Japan

MMAC-PC

11

WATM Reference Configuration

Conf #1: Network to support fixed Wireless Terminal

Conf #2: Network to support Mobile Wireless Terminal

Conf #5: Network to support PCS access

Conf #3: Network to support mobile switches

Conf #4: Wireless Ad-Hoc networks

Conf #6: PCS-ATM network Interworking

R4

End-user MobilitySupporting ATM NW

R4

AP AP

R6R7

R3R3

AP AP

R9R8

R10

R0

Network MobilitySupporting ATM NW

Mobile ATM NW

R1FixedATM NW AP

R2

R12

R11

R4

AP

R5

R5

R5

R5

R13

R5R5

R5

R14

R15

R16* R16* P

BS

R17*

BS

IWF

BSC

IWF

F

PCS Netwok

R15

R16

12

Wireless Access Architecture : Modular Access

• EMAS-Es are alienated from the radio access mechanisms

• Access point (AP) implements the radio access functions and deals with all the radio-specific functionality

• APCP : Access Point Control Protocol. The protocol providing standardized means of interaction between access point and EMAS-E

EMAS-E

EMAS-N

EMAS-N

NNI+M

NNI+MMT

AP

RTAP APCP

APCP

NNI+M ATM wireline links

Wireline Links to radio

transceivers

Radio LinksATM

Wireline links to AP

RT

RT

RT

EMAS : End-user Mobility supporting ATM switchEMAS-E : Entry switchesEMAS-N : network switches

13

WATM Protocol Stack

Physical Layer

SDH/SONET TAXI UTP-3

ATM Layer

wireless interface

wireless MAC

wireless DLC

ATM Adaptation Layer (SAAL, AAL1...ALL5)

Control and Signaling(Q.2931 + M, UNI 4.0, ...)

User Process(TCP, ...)

ATM Applications

ATM API (Xopen/Winsockets 2.0)

14

Wireless ATM Protocol StackMobile End Users

WMATMTerminal

User Applic.

AAL

ATM

WAL

UNI + M

SAAL

ATM

WAL

MATMTerminal

WirelessTerminal Adaptor

User Applic.

AAL

ATM

PHY

UNI + M

SAAL

ATM

PHY

PHY WAL

ATM

PHY WAL

ATM

Mobile End-Users Networks (1)

C-Plane

U-Plane

U-Plane

C-Plane

End User Mobility Supporting ATM Network (1)

WAL PHY

ATM

U-Plane

C-Plane

ATM

PHY

SAAL

ATM

PHYWAL PHY

ATM

ATM

PHY PHY

P-NNI+MUNI+M UNI+M

B-ICI+M

SAAL

ATM

PHY

APCP

SAAL

APCP

P-NNIUNIB-ICI

ATM

PHY

SAAL

ATM

PHY

PNNI+M P-NNI UNI+M UNI B-ICI+M B-ICI

WirelessAccessPoint

End-UserM.S. ATM

Switch

ATMSwitch

End-UserM.S. ATM

Switch

EMAS-E EMAS-N

15

Description of the Protocols

• APCP: Access Point Control Protocol used between the access point and the switch. foreseen only in the case of the need of the communication of information

related to the status of the radio resources from the access point to the switch.

foreseen that the Access Point does not perform ATM switching functions.• B-ICI’: B-ICI with supplemental signaling information to support the transport of

the mobility information • B-ICI+M: B-ICI with supplemental signaling information to support mobility

+M could represent more than one protocol operating on the interface• P-NNI’: P-NNI with supplemental signaling information to support the transport of

the mobility information • P-NNI+M: PNNI with supplemental signaling information to support mobility • UNI’: UNI with supplemental signaling information to support the transport of the

mobility information • UNI+M: UNI with supplemental signaling information to support mobility• WAL: Wireless Access Layer. The WAL is the wireless segment for end-to-end

ATM connection. It includes the wireless MAC, LLC, and PHY layers.

16

End-to-End Connection over WATM

• Protocol Stacks for a Full Integration of Mobile ATM Terminals to a Fixed ATM Network

Q.2931

ATM

M-LLC

PHY

SAALAAL

ATM

PHY

M-Ctrl

Q.2931

SAAL

User Service

M-MAC

M-PHY

User Service

M-Ctrl

SAAL

ATM

M-LLC

M-MAC

M-PHY

AAL

Q.2931

Mobile ATM Terminal Base Station Controller ATM Terminal

VCCend-pointUser plane

AT

M

Netw

ork

Wireless Channel

17

Functional Model for Modular Access Scheme

External ATM

network

ATMCT

CCFT

MMFT

RRCT

RTRT

RRC

RTR

CCF NSA

MMF SCF

Inf. 1

Inf.2

Inf.3

Inf.4

Mobile Terminal

ACFACFT

ATMC ATMC

APCF APCF

Wireless AP Mobility Enabled Switch

Inf.7

Inf. 5

UIM

IMFT

Inf.a

User Side Network Side

: logical interface : physical interface

MTSA

18

WATM Reference Interfaces and Protocols

WATM Interface / Protocol CommentsInf.1 ATM UNI or Q.2931 + “M” “M” protocol is used for mobility

specific messages including e.g.handovers and mobilitymanagement.

Inf.2 &Inf.3

Radio Link Control protocol- Access control protocol- Radio resource control protocol

Scope is limited to the Radio sub-system control

Inf.7 Access Point Control protocolInf.6 ATM UNI3.1/4.0 or Q.2931

+ “M”, or PNNI + “M”Could be the same as Inf.1/H2.1.2

--- MT radio sub-system control ------ AP radio sub-system control Possibly proprietary interfaceInf.5 PNNI or BICI + “M” “M” protocol is used for mobility

specific messages including e.g.handovers and mobilitymanagement.

19

Wireless mobile terminal side

• Mobility Management Function (MMFT) analysis and monitoring of the network, paging response, location update

• Call control and Connection control Function (CCFT) call set-up and release, access control, connection control

• Identity Management Function (IMFT) security related information, user dependent

• Mobile Terminal Security Agent (MTSA) additional security information, user independent

• Radio Transmission and Reception (RTRT) LLC, MAC, PHY layers for radio transmission

• Radio Resource Control function (RRCT) trigger handovers, monitor radio access, control radio resources

• Association Control Function (ACFT) set-up and release access to access point

• ATM Connection function (ATMCT) responsible for ATM connections, standard services (CBR, VBR, ABR, UBR)

Service and Connection Control Functional Entities

Radio and Access Control Functional Entities

20

Mobility supporting network side

• Access Point Control Function (APCF) paging, handover, AP management

• Call control and Connection control Function (CCF) call set-up and release, connection control, requests network and radio resources

• Network Security Agent (NSA) identity management, authentication, encryption, confidentiality control

• Service Control Function (SCF) management of service profiles, consistency checks

• Mobility Management Function (MMF) location management, handover, location data, subscriber identity

• Association Control Function (ACF) set-up and release access to mobile terminal

• Radio Resource Control function (RRC) management of radio channels, initiate handover

• Radio Transmission and Reception function (RTR) LLC, MAC, PHY layers, support of ATM traffic parameters

• ATM Connection function (ATMC) responsible for ATM connections, standard services (CBR, VBR, ABR, UBR)

Service and Connection Control Functional Entities

Radio and Access Control Functional Entities

21

Work Items for WATM

• Radio ATM Radio physical layer MAC for wireless channel (with QoS) Data link control for wireless channel errors Wireless control protocol for radio resource management

• Mobile ATM Hand-off control (signaling/NNI extensions, etc) Location management for mobile terminals Routing considerations for mobile connections Traffic/QoS control for mobile connections Wireless network management

22

Radio Access Layer (RAL) requirements: PHY layer• Definition of cell characteristics

frequencies, efficient re-use of frequencies, antennas, power, range

• Carrier frequency, symbol rate, modulation, coding, training sequences etc.

• Data and control interfaces to the radio unit

• Requirements Bit Error Rate (BER) <= 10-4, availability 99.5 % data rate: 25 Mbit/s range: indoor 30-50 m, outdoor 200-300 m power: 100 mW

23

Radio Access Layer (RAL) requirements: MAC layer• Supports

simultaneous access of several mobile terminals to the medium several ATM service classes (CBR, VBR, ABR, UBR) including QoS control

• MAC protocol and syntax definition, MAC control algorithms

• Interfaces to PHY and LLC layer

• Support of user mobility

• Requirements MAC efficiency: 60-75 % (over 90% is possible) data rates

• peak 25 Mbit/s

• sustained 6 Mbit/s

• still efficient for low rates (e.g., 32 kbit/s CBR)

24

Radio Access Layer (RAL) requirements: LLC layer• Layer between ATM and MAC/PHY layers to solve specific problems of

the wireless transmission

• Definition of LLC protocol and syntax wireless header, control messages

• Special functions for ATM service classes error control

• error detection and correction

• selective retransmission

forward error correction

• Requirements mandatory: ARQ (Automatic Repeat Request) optional: FEC for real-time services optional: meta-signaling to support handover

25

WMC projects summary(I)

Project Objective Frequency Data Rate Environm’t Multiple Access NoteMBS 3rd generation mobile

broadband system60 GHz 155 Mb/s Indoors/

OutdoorsTDMA(DSA)

RACE II(No further project)

MagicWAND

Wireless ATM networkdemonstrator

Demo:5 GHz

Research:17 GHz

Demo:24 Mb/s(20 MHz)

IndoorsTDMA/TDDMASCARA

OFDM (16 carriers)

Medical consultation,Web browser

MEDIANWireless Broadband

CPN/LAN forProfessional &

Residential MultimediaApplications

60 GHz 155 Mb/s Indoors TDMA/ATDDOFDM (512 carriers)

Successor of MBS project

SAMBASystems for Advanced

Mobile BroadbandApplications

40 GHz 34 Mb/sCellularMobile

To validate the MBS systemand the cellular mobile

broadband concept

CRABSCellular Radio Access

forBroadband Services

42 GHz 2~4 Mb/sCellularFixed

Cellular radio access tointeractive TV and broadband

services

CABSITCellular Access to

Broadband Servicesand

Interactive TV

42 GHzCellularFixed/

NomadicTDMA/CDMA

(DAVIC)

Interactive TV (surroundsound, TV guide, Pay TV)

Interactive Multimedia Services(VOD,NOD)

FRAMEFuture Radio Multiple

Access System2 GHz 2 Mb/s Outdoors - Hybrid TDMA/CDMA

- Code & TimeDivision AccessScheme (CATS)

To define the UMTS airinterface

AWACS ATM Wireless AccessCommunication System

19 GHz 34 Mb/s Indoors/Outdoors

26

WMC projects summary(II)

Project Objective Sponsor Frequency Data Rate Environmn’t Access Note

SWAN

SeamlessWireless ATM

Network:end-to-end ATM

transport tomobile users

AT&TBell Lab.

2.4 GHz 625 Kb/s(1 MHz)

Indoors TDMA/TDDFHSS modem

BAHAMABroadband Ad-

Hoc ATMArchitecture

AT&TBell Lab.

Free SpaceOptical

Link; 900MHz

1 Gb/s (PBS-PBS);

2 Mb/s(PBS-MT)

IndoorsDQRUMA

Wireless ATM LAN:PBS-PBS-MTarchtecture

AWAATM Wireless

AccessNTT 3~30 GHz

(TBD)80 Mb/s

(50 Mb/s oneway;Max 12 Mb/s per user)

Indoors/Outdoors

TDMA/TDDDCA

Dual mode accessto private & public

networks(standard CAI)

WATMnet PrototypeWireless ATM

System

NECC&C

2.4 GHz Type I: 8 MbpsType II: 25 Mbps

Indoors/Outdoors

TDMA/TDDMDR

ORATMRadio ATM Olivetti

Research Lab

2.4 GHz 6 Mb/s TDMA/TDDDistributedReservation

MAC

27

SAALQ.2931

PHY

M-Ctrl

W-LLC

User Service

AAL SAALATM

PHY

Q.2931

W-PHYPHY

W-LLCW-MAC

M-Ctrl

ATM

User Service

AAL SAALATM

PHY

Q.2931

W-PHYPHY

W-LLCW-MAC

M-Ctrl

ATM

User Service

AAL SAALATM

PHY

Q.2931

W-PHYPHY

W-LLCW-MAC

M-Ctrl

ATM

W-MACW-PHY

ATM

Base station

Wireless ATM terminal

ATM multiplexer

User Service

AAL SAALATM

PHY

Q.2931

User Service

AAL SAALATM

PHY

Q.2931

User Service

AAL SAALATM

PHY

Q.2931

ATM

PHY PHYPHYPHY

ATM multiplexerATM terminal

Wireless Access Layers for WATM

Multiplexing in Wired ATM Network Multiplexing in Wireless ATM Network(1) Mobile = Distributed Queue(2) Channel = Unreliable Bit Pipe

Issue : How to extend the ATM statistical multiplexing technique to the air interface to provide services of different types of traffic with a certain degree of guarantee in QoS?

28

MAC Requirements for WATM

General requirements Wireless MACRequirements

WATM MACRequirements

- Fault Tolerance- Scalability- Throughput- Delay- Addressing- Support for

Asymmetric Traffic- Fairness- Support for

Broadcasting andMulticasting

- Data Reliablity

- Transparency- Power Efficiency- Fading Immunity- To Handle Hidden

Terminal Problem- Simplified Frame

Structure- Support Handoff &

Roaming

- Service provision* :to support all ATMtraffic classes

- To guarantee QoSRequirements foreach traffic class

- To design a MACPDU for an efficienttransmission of ATMcells

- Error Control* : MAClayer CRC

• MAC Address scheme : use some form of IEEE 48 bit addressing• Multiple Access : TDMA with time division duplex and dynamic slot assignment• Architecture : Access point based using a centralized control

29

WATM MAC Model

( )1

( )2

( )n

하향 링크 스케쥴러

상향 링크 스케쥴러

DynamicParameter전송(in-band 또는out-of-band)

( )1

( )2

( )n

상향 링크

하향 링크

슬롯 할당 결과 통보

이동국 기지국

• Generic MAC Model

• Scheduler

- responsible for dynamic slot assignment- based upon the static and dynamic parameters

30

MAC Protocol Attributes of WATM

• Infrastructure 기지국 중심망 : dynamic slot assignment 방식에 적합 Ad-hoc 망

• Wireless access scheme FDMA/TDMA/CDMA/Hybrid

• 고속전송 모뎀구현에 적합한 FDMA/TDMA 복합방식을 우선적으로 고려함 .

• CDMA 방식 : 고속 전송 시 높은 시스템 복잡도 ; 밀리미터파 대역에서의 많은 가용 대역에 따라 CDMA 방식의 주파수 효율성으로 인한 장점이 상대적으로 미약해짐 .

• Duplex scheme Frequency Division Duplex (FDD)

• 모뎀설계 단순화• 모뎀 송수신 기능 구현이 이중화되어야 함

Time Division Duplex (TDD)• 송수신간의 turn-around time 에 의한 overhead

• 송수신간의 비대칭적인 traffic 부하에 따라 상하향간 frame 경계를 적응적으로 결정함으로써 효율적인 통계적 다중화 실현 가능

31

MAC Protocol Attributes of WATM (cont’d)

• Packet multiple access scheme Collision-free : reservation request 에 따라 up-link 상의 사용 slot 을

기지국이 미리 통보하는 polling 방식 Contention-oriented

• Slot assignment scheme Vertical slot allocation : 각 frame 내의 slot 위치를 고정하여 주기적으로

할당 Horizontal slot allocation : 매 slot 단위로 예약 Hybrid : service 유형별 traffic 발생 특성과 요구사항에 따라 VSA 와 HAS

를 혼합 적용 통계적 다중화 이득을 극대화 하기 위한 dynamic slot assignment 가

수행되어야 함 .

32

MAC Protocol Attributes of WATM (cont’d)

• Reservation request scheme Burst 첫번째 cell 에 대한 예약 요청

• 경쟁방식 : 상향링크에 정해진 예약 slot 에서 경쟁에 의해 예약 요청 정보를 전송• 지정방식 : 이동국별로 미리 지정된 예약 요청 slot 에서 경쟁없이 전송• 폴링방식 : 기지국이 일정 주기로 이동국을 polling 하여 예약 요청 통보하도록 함• 직교신호방식 : orthogonal signal 을 사용하여 다수 사용자가 동시에 예약요청

가능 Burst 의 나머지 cell 에 대한 예약 요청

• cell 단위 경쟁 : burst 내의 나머지 cell 들도 첫번째 cell 과 동일하게 취급 , 전송• burst 단위 예약 : 첫번째 cell 의 전송이 성공하면 나머지 cell 들을 polling 에

의해 일정시간동안 또는 burst 의 마지막 cell 이 전송될 때 까지 기지국에서 할당하는 slot 에 전송

• Signaling Down-link

• slot 단위 : slot 할당결과를 매 slot 마다 독립적으로 통보• frame 단위 : 결과 통보 신호를 그룹화하여 매 frame 당 전송

Up-link• in-band signaling : scheduling 에 필요한 dynamic parameter 를 up-link 로

전송되는 cell 에 piggybacking 하는 방식• out-of-band signaling : 지정된 신호 slot 을 이용하여 parameter 를 전송

33

FDD-Based MAC Proposals

• Idea : have two channels per BS coverage area, one for the uplink (UL) and the other for the downlink (DL) UL : used by the MTs for sending request and information packets,

according to some reservation and contention algorithm, DL : used by the BS in a scheduled mode, for sending acknowledgments

(ACKs) and information packets.

• Possible to have an almost immediate feedback from the BS in order to know (at the MT) if a request was successful or if a collision occurred.

• The MAC protocol proposals DQRUMA (Distributed Queuing Request Update Multiple Access) PRMA/DA (Packet Reservation Multiple Access with Dynamic Allocation) DSA++ (Dynamic Slot Assignment Protocol) DTDMA/PR (Dynamic TDMA with Piggybacked Reservation)

34

TDD-Based MAC Proposals

• Use only one carrier frequency to communicate both ways

• Save some hardware in the MTs since both the transmitter and receiver operate at the same frequency

• Add extra delay due to the turnover between transmitter and receiver modes

• The MAC protocol proposals MASCARA (Mobile Access Scheme Based on Contention & Reservation for

ATM) PRMA/ATDD (PRMA with Adaptive Time-Division Duplex Protocol) DTDMA/TDD (Dynamic TDMA with Time-Division Duplex Protocol)

35

Overall Comparison of the Protocols

DQRUMA DSA++ PRMA/DA DTDMA/PR MASCARA PRMA/ATDD DTDMA/TDD

36

MAC 프로토콜 AccessDuplexing

패킷 다원접속 방식

예약요청 방식

프레임길이

상하량 링크프레임 길이

슬롯 할당결과의 통보

MBSDSA:

Dynamic Slot AssignmentDSA++

TDMA동적 예약

방식경쟁 /폴링

DSA:고정

DSA++:가변

not specified

DSA:슬롯 단위DSA++:

프레임 단위

MEDIANDynamic PRMA: Packet

Reservation Multiple AccessTDMA/TDD

동적 예약방식

경쟁 고정가변

(AdaptiveTDD)

프레임 단위

MagicWAND

MASCARA:Mobile Access

Scheme based onContention And Reservation

for ATM

TDMA/TDD

동적 예약방식

경쟁 가변 가변(Adaptive

TDD)프레임 단위

BAHAMADQRUMA:

Distributed Queue RequestUpdate Multiple Access

TDMA/TDD

동적 예약방식

경쟁 고정 not specified 슬롯 단위

WATMnetMDR:

Multiservice DynamicReservation

TDMA/TDD

동적 예약방식

경쟁 고정트래픽 클래스간 가변

프레임 길이프레임 단위

SWANEC-MAC:

Energy Conserving MACTDMA/TDD

동적 예약방식

비경쟁 고정 가변 프레임 단위

일본우정성CRL

RS-ISMA: Slotted Idle Signal Multiple

Access with Reservation

TDMA/FDD

동적 예약방식

경쟁not

specifiednot specified not specified

WATM MAC 구현 사례 비교

37

Proposed MAC Frame Types

• Frame type 1

suitable for the low-bandwidth type of traffic, such as voice traffic • periodic short packets

• delay sensitive,

• can not afford to have long packetization delays.

used to support signaling messages.

• Frame type 2

to increase the efficiency of air interface usage by using one MAC header for several ATM payloads

38

MAC Frame Field Description

• The preamble field (preamble) (16 octets) used for synchronization purpose, etc.

• The control field (ctl) (2 octets) used to indicate the number of slots the mobile terminal wishes to send in its next

frame, the sender and receiver sequence numbers, and others to be defined

• The address field (address) (6 octes) used to identify the address of the corresponding mobile terminal at the MAC level

• The header field (hdr) (4 octets) for the ATM header, which does not include the HEC field, since a more powerful CRC

field covering the entire frame is added in the MAC frame.

• The payload field (payload) (48 octets) the same payload as in the ATM cell

• The CRC field (2 octets) for the error detection for the whole MAC frame; CCITT CRC-16 is a possible

candidate.

• The Guard (Gd) field used to prevent from frame overlapping in the uplink due to varying propagation

delays among mobile terminals

39

Location Management

• LM enables the network to communicate with MTs by managing the information about the location of the terminal

• LM = Mobile tracking + Mobile locating Mobile Tracking

• Network elements updating procedure about the location of mobile entities

• Mobile registration + updating

Mobile Locating• The procedure by which a network node determines the location of the mobile for

the delivery of incoming calls

• May be executed explicitly prior to call setup or may be an integral part of the call setup procedure

• Use the information acquired during the tracking phase

40

Architectural Model for LM in WATM

AP

AP

AP

RPRP

LS AUS

LS AUS

E-MAS-E

AP AP

RP

Integrated Approach

EMAS-E

Modular Approach

• Location Server (LS): maintaining the database of associations

between the permanent and temporary AESA(ATM End System Addresses)s of mobile terminals

keep track of service-specific information for each MT

executes query and update protocols to retrieve and modify database entries

• Authentication Server (AUS): maintaining a secure database of

authentication and privacy related information for each MT

may implement an authentication protocol with an EMAS or an MT directly.

• Mobile Terminal (MT): initiate location updates and participate in

authentication and privacy protocols• End-user mobility enabled switch (EMAS):

identify connection set-up messages destined to MTs invoke location resolution functions All edge EMASs may be required to execute location update functions. “Home” EMASs require the ability to redirect a connection set-up message and perhaps maintain the LS and AUS. may be required to participate in the redirection of a connection set-up message to the current location of an MT.

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LM Requirements for WATM

• User transparency• Location and user information

confidentiality• Cell/network identification• Minimize signaling load• User controlled access to choose

desired network under multi-operator conditions

• Access restriction• Roaming

• Easy inter-working• Support of paging• Scalability• Distributed Servers

• Standardized location management• Registration using a standard

mechanism • Association• Security for preventing unauthorized

access as well as to ensure privacy• Integrated location databases for

authentication and location tracking with mobility-enabled switches

• Performance: latency in registration, database updates and queries

• Routing

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Starting points for WATM LM

• IS-41 and GSM MAP(mobile application part ) Currently for CO-cellular network Isolates effect for mobility from PNNI routing protocol Explicit “search” procedure prior to call setup Proposed scheme : (external) LR scheme

• PNNI routing protocol Routing protocol for private ATM networks Propagates reachability information No explicit “search” procedure prior to call setup Proposed scheme : mobile PNNI scheme

• Extension of the PNNI routing protocol to support MN

– Use of the PNNI routing protocol for reachability information(RI)

– Scope parameter for the restriction of RI update

• No explicit “search” procedure prior to call setup

– Connection setup combined with mobile locating

• Requires additional routing optimization process

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Comparison

Item Mobile PNNI LR

Address space partition Not required Required

Resource allocation for call setup

Not optimized Optimized

Application to public network

Not Applicable Applicable

Modification of ATM signaling and routing

Required Not required

Performance Superior in low CMR Superior in high CMR