Publishing Venue
Motorola
Related People
Authors:
Jeff Anderson
•
Terry Bale
•
Steve Surwillo
Abstract
When attempting confirmed message delivery in a Private DataTAC system, the Radio Data - Link Access Procedure air interface protocol is responsi- ble for the Automatic Retransmission reQuest (ARQ) reliability mechanism for the network. For confirmed message packets, this means re-transmit- ting packets when requested by the receiving device or when no acknowledgment is received indicating that the packet was received error free. Unfortunately, the retry number is valuable informa- tion that is not included in the packet header and could be used to increase network performance and manageability.
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Developments Technical 0 M MOTOROLA
DELIVERY ATTEMPT EMBEDDED' IN RD-LAP HEADER
by Jeff Anderson, Terry Bale and Steve Surwillo
ABSTRACT
When attempting confirmed message delivery in a Private DataTAC system, the Radio Data - Link Access Procedure air interface protocol is responsi- ble for the Automatic Retransmission reQuest (ARQ) reliability mechanism for the network. For confirmed message packets, this means re-transmit- ting packets when requested by the receiving device or when no acknowledgment is received indicating that the packet was received error free. Unfortunately, the retry number is valuable informa- tion that is not included in the packet header and could be used to increase network performance and manageability.
MOTIVATION
The "retry" routines used in our Private DataTAC systems provide efficient means of attempting message delivery - however, if the "retry" information was passed on to our data radio modems, the devices could make logical choices that could effect system performance. This change could also assist field engineers in evaluating sys- tem performance/coverage without assistance from an additional field engineer or the limited capabili- ties of host simulators.
PROBLEM DESCRIPTION
Currently in Private DataTAC networks the RD- LAP logical link layer (LLC) attempts to reliably deliver confirmed data packets across the air inter- face with an automatic retry mechanism. Currently the receiving device has no way of knowing how many attempts that it actually took the network to deliver the message. Long packets may allow the receiver to correctly receive the header information and calc...
