Feedback Based Real-Time MAC (RT-MAC) Protocol for Wireless Sensor Networks

This paper presents a MAC layer protocol, called RTMAC, for real-time data streaming in wireless sensor networks. RT-MAC eliminates need to contend for a wireless medium by potential transmitting nodes in a range by introducing feedback control packet, called Clear Channel (CC). RT-MAC maximizes spatial channel reuse by avoiding false blocking problem of RTS/CTS exchange based wireless MAC protocols. RT-MAC reduces contention duration for control packets to facilitate faster traveling of data packets; thus, it reduces end-to-end delay of data packet transmission. RT-MAC facilitates periodic delivery of data packets as well as fast reporting of an alarming event. This paper provides the upper bounds of end-to-end delay of data packet transmission with periodic sleep/listen schedule for RT-MAC protocol. In this paper, extensive simulation results are presented. RT-MAC supports single stream communication between a randomly selected source and sink node pair as well as multi-stream non-interfering communication among different source and sink node pairs.