1. Wireless ATM Development Scenario
성 단 근 (成 檀根)
한국과학기술원 (KAIST)
Communication Networks Research Lab.

2. Communication Networks Research Lab.
Contents
Wireless ATM ?
Requirements
Radio ATM : PHY, MAC, DLC
Mobile ATM : Handoff, LM
Testbed Systems (WATM Projects)
Development Scenario
Conclusions
Communication Networks Research Lab.

3. Communication Networks Research Lab.
Wireless ATM ?
Wireless
Fixed / Wired
Mobility
Cordless-based
Approach
Cellular-based
Approach
PSTN
First Gen.
CT-1
Analog
Analog
Cellular
Fast
PSDN
IMT-2000
CT-2
Public
Cellular
Second Gen.
Slow
Satellite
mobile
ISDN/
B-ISDN
Digital
cellular
CT3
PCS
Wireless
ATM
Movable or
PCN
Still
Third Gen.
Private
(indoor)
Cordless
Telephone
Wireless LAN (IEEE )
Fixed
B - ISDN
UMTS / IMT-2000
W-ATM
0.1 1 10
100
Mbps
Communication Networks Research Lab.

4. Wireless ATM as a General Concept
Communication Networks Research Lab.

5. Standardization (ATM Forum)
Working Group (June `96)
Recommendations (Dec. `98)
Mobile ATM
B1. Handoff control
B2. Location management for mobile terminals
B3. Routing for mobile connections
B4. Traffic/QOS control for mobile connections
B5. Wireless network management
User Plane
Control Plane
Mobility Control
ATM Adaptation Layer
ATM Layer
Wireless
Control
Data Link Control
Radio ATM
A1. Radio physical layer
A2. MAC for wireless channel (with QOS)
A3. Data link control for wireless channel
A4. Radio resource management
Medium Access Control
Radio Physical Layer
Radio Access “R” Specification
Mobility “M” Specification
Communication Networks Research Lab.

6. Multimedia Service Classes and QoS
CBR (Constant Bit Rate)
VBR (Variable Bit Rate) : Real-time and NonReal-time
ABR (Available Bit Rate)
UBR (Unspecified Bit Rate)
Communication Networks Research Lab.

7. Communication Networks Research Lab.
Problems
Medium (Radio ATM)
ATM assumes reliable transmission media
e.g.) optical fiber => error correction
Efficient transmission of short cells
QoS guarantee over unreliable radio link
Mobility (Mobile ATM)
Signaling modifications to support mobility
Addressing (ATM, MAC, VCI/VPI)
Security
Communication Networks Research Lab.

8. Communication Networks Research Lab.
Physical Interface
Frequency Band
2.4GHz band : 6-8 Mbps
5 GHz band : 25Mbps (50 kcells/sec to the ATM Layer)
17 GHz band : 155Mbps
60 GHz band : 155Mbps or 622Mbps...
Unreliable Link (Error Source)
Multi-path fading (Dominant source)
High frequency and traveling speed => fading rate
Cell Size and Channel Utilization
Packet Size
> 1cell / PDU for effective utilization
Communication Networks Research Lab.

9. MAC Protocols for Radio Access Interface
Integrate Services and Guarantee QoS
Distributed (WATM LAN) or Central
TDMA/Asymmetrical TDD with dynamic slot assignment (ATM Forum)
Access Mode
Circuit Mode
Packet Mode
TDMA
Paradigm
CDMA
Paradigm
TDMA
FDMA
CDMA ? ? ?
DSA/DSA++
Dynamic TDMA
DQRUMA
Slotted CDMA
Multicode
Communication Networks Research Lab.

10. Communication Networks Research Lab.
Error Control (DLC)
Channel Error Recovery
Interleaving
Forward error control (FEC)
Dual - level FEC
Link Error Recovery
Auto Repeat reQuest (ARQ) retransmission
Go-back N
Selective repeat
FEC
Communication Networks Research Lab.

11. Communication Networks Research Lab.
Handoff Issues
Hard vs. Soft Handoff
Path Extension vs. Path Rerouting
Static COS vs. Dynamic COS Selection
Control Plane vs. User Plane Signaling
QoS Guarantee at Handoff
Different user load at base stations
Reserving capacity => waste of system resource
Communication Networks Research Lab.

12. WATM Project - Magic WAND
Private, Indoor, Business Customer Premises Network
Desktop, Nomadic User, Hand Portable Applications
ACTS Projects
17GHz
TDMA/TDD
50m Cell, 15 km/h
MASCARA
Wireless DLC
Intra-Switch Lossless Handover
ATM
Network
AP : Access Point
Communication Networks Research Lab.

13. Communication Networks Research Lab.
WATM Project - MEDIAN
High Speed Wireless Customer Premises LAN
Professional & Residential Multimedia Applications
ACTS Projects
34 or 60 GHz
OFDM (512 Carriers)
TDMA/TDD
Communication Networks Research Lab.

14. Communication Networks Research Lab.
WATM Project - BAHAMA
Broadband Adaptive Homing ATM Architecture
Ad-Hoc Wireless ATM LAN
PBS : ATM Switching Functionality + Wireless
Access Interfaces
AT&T Bell Lab.
900MHz
???
TDMA
DQRUMA
Homing Algorithm
Broadcast Scheme
Communication Networks Research Lab.

15. Communication Networks Research Lab.
WATM Project - WATMnet
A Prototype Microcellular Wireless ATM Network
Mobility Enhanced ATM Signaling (Q.2931+)
NEC USA, C&C Research Lab.
2.4 GHz
TDMA/TDD
p/4 QPSK
Dynamic TDMA
AAL 3/4 & 5
Handover Switch Scheme
Communication Networks Research Lab.

16. Communication Networks Research Lab.
WATM Project - SWAN
Indoor Environments
AT&T Bell Lab.
10-20m Cell
GHz
TDMA/TDD
FHSS modem
Token Passing MAC
Communication Networks Research Lab.

17. Communication Networks Research Lab.
WATM Project - MBS
Public and Private System, Indoor and Outdoor
All Multimedia Applications and B-ISDN Compatible
ACTS Projects
60GHz
TDMA/FDMA/FDD
4 and 16 OQAM
SR-ARQ
Network Handover with Server
Communication Networks Research Lab.

18. Communication Networks Research Lab.
WATM Project - SAMBA
Advance the MBS Evolution and Promote Its Standardization
Medical and Broadcast Applications
ACTS Projects
40GHz
Communication Networks Research Lab.

19. Communication Networks Research Lab.
WATM Project - AWA
Wireless ATM LAN and Public Networks
Dual Mode Access
ATM Services
NTT
TDMA/TDD
QPSK or p/4-QPSK
SR-ARQ
ATM-based
multimedia network
Media Server
Micro-cell/Pico-cell at public
spaces like Hotel, Airport,
Rail-station, Restaurant etc.
Hand-held
portable
multimedia
terminal
ATM`-SW
Communication Networks Research Lab.

20. Communication Networks Research Lab.
WATM Project - Summary
Communication Networks Research Lab.

21. Technology Tree for Wirelss ATM
Wireless ATM
Radio ATM
Mobile ATM
PHY
MAC
DLC
Handoff LM
Frequency Bands
Data Rates
Environments
Channel Coding
Cell Size
Modulation
Multiple Access
Service Integration
Buffering
Hard vs. Soft
Mobile Tracking
QoS Guarantee
Cell Integrity
Extension vs. Rerouting
Mobile PNNI vs. LR
Distributed vs. Central
Transfer Delay
Static vs. Dynamic COS
Utilization
Control vs. User Plane
ARQ vs. FEC
QoS Guarantee
Hybrid ARQ/FEC
Forward vs. Backward
Communication Networks Research Lab.

22. Communication Networks Research Lab.
WATM Scenario
Communication Networks Research Lab.

23. Communication Networks Research Lab.
WATM Scenario - Stage 1
Design Objective
Wireless Channel Design
WATM Terminal + Base Station (BS)
Carrier frequency : 2.4 GHz, 5.2GHz, 17GHz, 60GHz, etc.
Radio Propagation Characteristic : Indoor, Outdoor
Multiple Access Scheme : TDMA, CDMA, etc.
Modulation : QPSK, OQAM, OFDM, etc.
Channel Coding : Interleaving, FEC
Antennas : Omnidirectional, Directional, Array
Cell Size and Link Utilization
Communication Networks Research Lab.

24. Communication Networks Research Lab.
WATM Scenario - Stage 2
Design Objectives
Local mobility
Service Integration
WATM Terminal + BS + Switch
Dynamic Scheduling : DSA, DQRUMA, etc.
Services : CBR + VBR + ABR + UBR
Error Control : ARQ, FEC, ARQ/FEC
Hard handoff vs. Soft handoff
Forward handoff vs. Backward handoff
Communication Networks Research Lab.

25. Communication Networks Research Lab.
WATM Scenario - Stage 3
Design Objectives
Network mobility
Interworking function
WATM Terminal + BS + Switch + ATM Networks
Handoff Signalling : Control Plane vs. User Plane
Path Routing : Path rerouting vs. Path Extension
QoS Guarantee During Handoff Procedures
Location Management
Interworking with Cellular, PCS, ATM LAN, etc.
Communication Networks Research Lab.

26. Communication Networks Research Lab.
Conclusions
Extension of ATM Services to Wireless Terminals
Technology Tree for WATM (Radio & Mobile ATM)
Various WATM Projects in Progress
Magic WAND, MEDIAN, BAHAMA, WATMnet, AWA, SWAN, MBS, SAMBA
WATM Scenario
Stage 1 : Wireless Link Design
Stage 2 : Service Integration and Local Mobility
Stage 3 : Network Mobility and Interworking
Communication Networks Research Lab.