IEEE 802.12 Demand Priority and multimedia

The Demand Priority MAC protocol

“…As such, the TTT must represent the smallest delay needed by any application, similar to the FDDI Target Token Rotation Time 161, and a figure of 10 ms seems reasonable for many LAN-based multimedia applications. So, if a station is granted 10 Mb/s and the TTT is set to 10 ms, then the station may not send more then 100 kb of high priority traffic in any period of 10 ms [4]. The TITis, inasense,acontract: ifstationsdonotexceed their bandwidth allocation in any period TTT then they will always be able to transmit within the period TIT.…”

“…ith two priority levels the networkcan provide W a service that guarantees bandwidth and bounds the access delay [4]. There are two different ways by which such a service can be provided [SI.…”

An overview of IEEE 802.12 demand priority

“…The High priority multimedia traffic will take precedence over the computer data traffic, and if it is ensured that the total High priority traffic does not exceed say 90% of the available bandwidth minus overheads, the High priority traffic will experience very low delays. One mechanism to do this is the Target Transmission Time algorithm, described in [3], [4] and [5].…”