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
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