Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

INTEGRATING LIMITED TRANSMISSION LENGTH, CHANNEL REQUEST MECHANISM AND A RELIABLE DATA LINK LAYER USING SELECTIVE BLOCK REJECT MECHANISM FOR MAXIMUM THROUGHPUT IN A PACKET DATA SYSTEM

IP.com Disclosure Number: IPCOM000008665D
Original Publication Date: 1998-Jun-01
Included in the Prior Art Database: 2002-Jul-02
Document File: 3 page(s) / 148K

Publishing Venue

Motorola

Related People

Tim Spets: AUTHOR [+2]

Abstract

In a connection oriented LLC (Logical Link Control OS1 layer 2 data link layer) using a Selective Block Reject retransmission scheme, the peer notifies the sender not only if a datagram has been received but what portions have been received. It uses sequence numbers to distinguish one datagram from another. The acknowledgment information is critical in reducing needless re-trans- missions.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 46% of the total text.

Page 1 of 3

MOTOROLA Technical Developments

   INTEGRATING LIMITED TRANSMISSION LENGTH, CHANNEL REQUEST MECHANISM AND A RELIABLE DATA LINK LAYER USING SELECTIVE BLOCK REJECT MECHANISM

FOR MAXIMUM THROUGHPUT IN A PACKET DATA SYSTEM

'queue' which is ordered by sequence number. This insures when the channel is available it can send the datagrams (that consist of original datagrams or selected blocks thereof for re-transmission) in order of priority, oldest to newest. This is done by begin- ning with the smallest sequence number in the queue and sending each datagram marked 'ready to send,' up to the highest sequence number (within the constraints of maximum number of bytes per transmission). For those that are going to be transmitted at the same time, it will select only one re-transmission timer for all of them and they are all associated together.

SEND ACKNOWLEDGMENT PROCEDURE

  When the peer receives the datagrams, it is notified of a "transmission reservation length" which notifies it of how many bytes are being transmitted. As each datagram is received the information of what has been received is updated in the receive window 'queue' (which is ordered by sequence number) and is marked with "Ack pending." When an indication that all of the datagrams sent in the single transmission have been received (partial, full or lost) an "Ack Needed" condition is set. This insures that no datagrams are acknowledged until the entire transmission has completed. If more data- grams are received from subsequent transmissions while waiting for the channel they will repeat the above process, marking each sequence number with 'Ack pending.'

  When the channel is available (and Ack Needed condition is set) the receiver can create a Multiple Acknowledgment in order of priority, oldest to newest. This is done by beginning with the smallest sequence number in the receive window 'queue' and adding information for each datagram marked

c Molordr, Inc. ,998 17 Jim? 1998

by Tim Spets and Keith Parmer

  In a connection oriented LLC (Logical Link Control OS1 layer 2 data link layer) using a Selective Block Reject retransmission scheme, the peer notifies the sender not only if a datagram has been received but what portions have been received. It uses sequence numbers to distinguish one datagram from another. The acknowledgment information is critical in reducing needless re-trans- missions.

  This Publication is designed for an RF network where the transmission medium is a contention resource that requires a request followed later by a channel grant before sending datagrams in the transmit window or 'queue,' and is limited by a maximum number of bytes being transmitted at a time, this procedure will assist the 'queueing' effect that will cause multiple datagrams to be sent at once. By using the knowledge that they are all in the same transmission, and using all of the informa- tion in the Multiple Acknowledgment Packet, the sender can prevent needless re-transmissions.

  Note: The kno...