Wireless ATM networks

1
Wireless ATM networks

• new architecture elements and functionality
  supporting mobility

2
Service scenarios

• wireless LAN networks with dynamically modified
  structure
• broadband wireless access networks
• wireless point-to-point links

3
Possible RD directions

• GSM System
• multimedia support
• QoS support

• ATM System
• radio access
• mobility

4
New requirements for WATM

• Wireless access (ETSI BRAN)
• shared medium
• relatively high error ratios
• relatively low bit rates
• Mobility (ATM Forum)
• Location Management (LOC)
• Handover Control (HOC) without loosing
  connections and with QoS persistence

5
Wireless ATM System

• New components
• ATM switch with M UNI/NNI interface
• ATM base station with M UNI/NNI and W UNI
  interfaces
• ATM mobile terminal with W UNI interface
  mobility support software radio ports

6
WATM Radio Access

• PHY Layer
• MAC Layer
• LLC Layer

7
WATM PHY Layer

• Cell radius
• 50-500 m (microcell or picocell environment)
• Band
• 5GHz Unlicensed NNI band (USA)
• "Hiperlan" band (Europe)
• in future 20/30 or 60GHz (limited mobility)
• Bit rate
• 25Mb/s (2-4Mb/s sustained, 5-10Mb/s peek VCs)
• Modulation
• QPSK/GMSK or OFDM
• Access Method
• TDMA/TDD

8
WATM MAC Layer

• Reservation based MAC protocols
• Piggybacking
• Assigned reservation slots
• Contention slots
• Pooling based MAC protocols
• Generic frame structure (TDMA/TDD)

9
WATM LLC Layer

• Error detection with retransmission (SREJ ARQ)
• Forward error correction

10
WATM Mobility Support

• Location Management (LOC)
• Handover Management (HOC)

11
WATM Location Management

• Extended addressing for MTs
• home address (HA)
• foreign address (FA)
• Possible solutions
• FA of the MT is maintained by its home ATM switch
• Designated LOC servers maintaining HAs to FAs
  mapping exists in the system

12
WATM Handover Control

• Possible initiators
• MT vs. BS
• old-BS vs. new-BS
• Possible strategies
• New connection strategy
• Path extension strategy
• Connection Tree Strategy

13
WATM Status

• Projects
• Race II
• ACTS (Advanced Communications Technologies and
  Services)
• Magic WAND
• AWACS (ATM Wireless Access Communication System)
• Samba (System for Advanced Multimedia Broadband
  Applications)
• MEDIAN
• Standards (ETSI)
• HIPERLAN Type 2 wireless local access
• HIPERACCESS wireless local loop
• HIPERLINK wireless point-to-point link

14
THANK YOU