Wireless ATM

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Wireless ATM
PRESENTED BY

• NIPURBA KONAR

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Overview

• What is ATM?
• The Promise of Wireless ATM
• Transition from Wired ATM
• Advantages and Disadvantages
• Research and Implementations
• Goals of the Project

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What is ATM?

• Asynchronous Transfer Mode (ATM)
• A networking technology developed by the
  telephone companies to handle all types of data
  using fixed 53-byte cells, or packets.
• Creates virtual point-to-point circuit
  connections between the source and the
  destination.
• Data rates from 25 to 622 Mbps.

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What it does?

• The small cell size allows ATM to transmit
  video, audio, and computer data over the same
  network, while guaranteeing a preset QoS level
  for each.

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The Promise of W-ATM

• Extension of LAN for mobile user
• Simplified wiring and configuration
• Provide high-speed data access for users without
  need for a new wired infrastructure
• Create unforeseen opportunities for future
  applications

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W-ATM
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Transition Issues

• Physical Layer
• WATM requires high speed radio modem capable of
  providing reasonable transmission
• Target bit rates of WATM PHY is in the range of
  25Mbps
• Moreover burst operation must be supported
• Modulation techniques such as QAM and QPSK can be
  used

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Operating Frequency
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Transition Issues

• Data Link Layer
• Mitigates effect of error before ATM CELLS are
  released in the channel
• Error detection and retransmission techniques are
  used for this purpose
• Additional UBR allocations are made at data link
  layer is added to support retransmission

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Proposed Architecture
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LOCATION MANAGEMENT

• Home base station maintains a pointer
• Standard SET UP MESSAGE
• RELEASE message returned with new
  information element if device is away
• SET UP MESSAGE is sent with foreign address as
  routing ID

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HAND OFF CONTROL

• Dynamically support active connection during
  migration
• Mobile IP v/s WATM
• Mantainance of routing optimality and QOS
• Signal such as HAND OFF_CONFIRM
• HAND OFF REQUEST USED

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ADANTAGES OF W-ATM

• Free to Roam
• Flexible bandwidth allocation
• Efficient multiplexing of traffic
• Flexibility of reusing same frequency
• Soft handoff without any data loss

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Disadvantages of W-ATM

• Delay to multi-path interference
• Hop-by-hop routing method not adequate
• Virtual connection takes longer
• Finding a suitable wireless channel

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Goals

• Integration of wireless physical layer , medium
  access control and data link layer
• Analyze the effects of mobility on a wireless ATM
  network
• Hand off control and location management

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THANK YOU