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ADAPTIVE METHOD FOR ACKNOWLEDGEMENT OF DATA PACKETS IN ERROR-PRONE HIGH-DELAY DATA CONNECTIONS

IP.com Disclosure Number: IPCOM000008690D
Original Publication Date: 1998-Jun-01
Included in the Prior Art Database: 2002-Jul-03
Document File: 1 page(s) / 66K

Publishing Venue

Motorola

Related People

Gregory W. Cox: AUTHOR

Abstract

Raw (or transparent) wireless data connections are generally error-prone and have high delays. Users of these circuits must be protected from channel errors in the most efficient manner possible to conserve limited available throughput, This can be accom- plished by a selective ARQ reliable data protocol. Acknowledgements feeding back from the receiver to the transmitter specify which data packets were received correctly and which require retransmis- sion. If this feedback is corrupted, then data may be retransmitted needlessly, wasting limited throughput. In general, it requires much fewer resources to send an acknowledgement or a request for retransmission than it does to send an entire packet.

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MOTOROLA Technical Developments

ADAPTIVE METHOD FOR ACKNOWLEDGEMENT OF DATA PACKETS IN ERROR-PRONE HIGH-DELAY DATA CONNECTIONS

by Gregory W. Cox

where

i- = 1 .O initially (2)

r = min(fi,+ r + ix,) when duplicate good packet is received

r = max(r,.,, r - KC<)

BACKGROUND

  Raw (or transparent) wireless data connections are generally error-prone and have high delays. Users of these circuits must be protected from channel errors in the most efficient manner possible to conserve limited available throughput, This can be accom- plished by a selective ARQ reliable data protocol. Acknowledgements feeding back from the receiver to the transmitter specify which data packets were received correctly and which require retransmis- sion. If this feedback is corrupted, then data may be retransmitted needlessly, wasting limited throughput. In general, it requires much fewer resources to send an acknowledgement or a request for retransmission than it does to send an entire packet.

SOLUTION

  Acknowledgements and requests for retransmis- sion are repeated in multiple independent packets. The number repetitions is governed by the adaptive procedure described below. Repeating acknowl- edgements can directly prevent the opposing trans- mitter from unnecessarily retransmitting a "good" packet due to a lost or corrupted acknowledgement feedback. Repeating requests for retransmission can also prevent the opposing transmitter from unneces- sary retransmissions caused by windowed data tran...