How Good is Opportunistic Routing? – A Reality Check under Rayleigh Fading Channels
Rong Zheng and Chengzhi Li
Considerations of realistic channel dynamics motivate the design of a new breed of opportunistic schemes, such as opportunistic transmission, scheduling and routing. Compared to their deterministic counter part, opportunistic schemes have been shown to increase network throughput, and/or reduce delay in limited experimental/simulation scenarios. In this paper, we propose analytical models that characterize the performance of routing protocols in lossy wireless networks with Rayleigh fading channels. We investigate the efficiency of a few representative deterministic and opportunistic routing protocols under both light-loaded and saturated traffic conditions. This work deviates from existing work that assumes idealistic packet reception, and is thus of practical relevance. Our study shows that opportunistic routing significantly outperforms its deterministic counterpart in average effective progresses made in single-hop transmissions. In deterministic routing schemes, tuning of parameters based on node density is critical to achieve optimal performance.
Keywords: Opportunistic routing, Rayleigh fading channel, average progress.