A Packet Scheduling Scheme Using Multicast RTS in Wireless Mesh Networks

One of the problems in wireless mesh networks is HOL (Head of Line) blocking at relay nodes. To overcome that problem, packet scheduling schemes using the MRTS (Multicast Request to Send [RTS]) frame, an extension of the RTS frame, have been proposed. The sender first multicasts an MRTS frame to multiple destination candidates. Then the sender transmits the data packet to the candidate which earliest returns a CTS frame. That mechanism could solve the HOL blocking problem. In principle, as the number of the candidates increases, the transmission success rate increases; however the overhead also increases. Under the existing scheduling schemes, the sender always arranges more than two candidates, which would increase the overhead. In this paper, to reduce the overhead, we propose a scheduling scheme which restricts the number of candidates to not more than two at any time. Simulations shown that, in comparison with the existing scheme, our scheme provides higher throughput and fairness. (C) 2014 Wiley Periodicals, Inc.