Reactive TDMA Slot Assignment Protocol in Wireless Ad Hoc Networks

In mobile wireless networks such as ad-hoc networks, sensor networks and mesh networks, wireless multihop transmission is adopted for data message transmission. For achieving higher throughput and shorter transmission delay, TDMA is one of more effective methods which avoid collisions and contentions than CSMA/CA and RTS/CTS. This paper proposes a reactive TDMA time slot assignment method in which time slot assignment gets active only when wireless multihop transmission is initiated. Here, a slot is assigned not to a mobile computer as in a conventional proactive method but to a wireless communication link included in an active wireless multihop transmission route. TDMA time slot assignment restrictions are clarified and slot assignment and release protocols are designed. Performance of the protocol is evaluated in simulation experiments which show that higher successful assignment ratio and shorter end-to-end transmission delay than the conventional proactive methods are achieved.