Traffic‐aware routing for real‐time communications in wireless multi‐hop networks
Shouyi Yin, Yongqiang Xiong, Qian Zhang, Xiaokang Lin · Wireless Communications and Mobile Computing · 2006
Abstract In this paper, we propose a novel traffic‐aware routing metric for real‐time communications (RTC) in wireless multi‐hop networks. Our routing metric, path predicted transmission time (PPTT), is designed to choose a high‐quality path for RTC flow between a source and a destination. PPTT can serve as both single‐radio and multi‐radio routing metric for RTC flow. RTC has critical quality of service (QoS) requirements in terms of delay, bandwidth and so on. Traditional measurement‐based routing schemes ignore the interference from the coming RTC flow itself (i.e. self‐traffic), so they may choose the inefficient path to serve the coming RTC flow due to the inaccurate quality estimation of the transmission path. PPTT takes explicit consideration of both self‐traffic and neighbouring traffic interfering with the RTC flow, and thus offers an accurate estimation of path transmission delay. Through differentiating the links by the wireless channel/radio they are using, PPTT has the capability to choose a high‐quality path for the coming RTC flow in both single‐radio and multi‐radio networks. To evaluate the performance, we implement PPTT scheme and study its performance in a wireless multi‐hop testbed consisting of 32 nodes equipped with two IEEE 802.11a/b/g combo cards, and we also conduct extensive simulations with different random topologies in network simulator NS‐2 for a more comprehensive comparison. The results of simulation and experiment show that this routing metric outperforms other non‐traffic‐aware one such as expected transmission count (ETX) and weighted cumulative expected transmission time (WCETT) in terms of delay and goodput in both single‐radio and multi‐radio wireless networks. Copyright © 2006 John Wiley & Sons, Ltd.