Wireless ATM PRESENTED BY : NIPURBA KONAR

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

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.

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.

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

W-ATM

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

Operating Frequency

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

Proposed Architecture

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

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

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

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

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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