Comparative Study of Routing Metrics for Multi-Radio Multi-Channel Wireless Networks

The multi-radio multi-channel network architecture has been recognized as one of the promising approaches to improve the system throughput of IEEE 802.11-based multi-hop wireless networks. In this paper, we study the routing issues under this new network architecture and propose a new routing metric, called AETD (adjusted expected transfer delay). The key idea of AETD is to consider both delay and jitter of candidate routes when making the routing decision. It is designed to select a route on which hops operating on the same frequency channel are separated as far as possible. This way, interference and channel contention may be minimized along the selected route and the system throughput may be improved. Our in-depth simulation shows that the proposed AETD routing metric outperforms several other routing metrics significantly, including HOP (hop count), ETX (cumulative expected transmission count), CETT (cumulative expected transmission time), and WCETT (weighted cumulative expected transmission time).