CSMA-TGT: Carrier-Sense Multiple Access with Transmission Guiding Tracks

In a bid to develop a wireless MAC protocol with the lowest possible latency for isochronous traffic such as typically generated by real-time industrial applications, we have come up with a new collision-free CSMA protocol. In this protocol, each packet from a traffic flow is assigned a string of regularly spaced sensing slots which act as guiding tracks to coerce its transmission and retransmissions to be contiguous. The first of these slots is timed as close as possible to the generation time of the packet to minimize its access delay. Across traffic flows, these strings of slots are interleaved such that a later flow is able to start transmitting the moment an earlier flow has completed its last transmission. Using the OMNeT simulator, we compare the packet delivery delay bound for this new protocol against several existing protocols.