Efficient 2-D mesh election algorithms for OFDMA-based wireless mesh networks

Abstract

Recently, wireless mesh networks (WMNs) have received enormous attention for wireless backbone network as well as sensor network due to its flexibility and cost-effectiveness in deployment. Particularly, IEEE 802.16-2004 based on time division multiple access (TDMA) with orthogonal frequency division multiplexing (OFDM) air interface supports mesh mode operation for last-mile connection to backhaul networks by means of distributed control functionalities. For the distributed operation, network and scheduling information is conveyed via control channels under a channel access protocol, named mesh election (ME). Meanwhile, in order to provide high data rate multimedia services, orthogonal frequency division multiple access (OFDMA) has been widely accepted by many proponents in the standardization parties such as 3GPP and IEEE 802.16. In these respects, we propose efficient two-dimensional ME protocols for OFDMA-based WMNs. The proposed protocols simply work by separating its procedure into two steps, subframe-and subchannel-level elections, which satisfy collision-free criteria for broadcast transmission and reception. Also, we suggest summation and product metrics for subchannel-level election, which have better performance in terms of transmission interval and resource utilization than that of independence metric by increasing the probability that a node succeeds in subframe- and subchannel-level elections subsequently.