Design of a Channel Characteristics-Aware Routing Protocol

Radio channel quality of real-world wireless networks tends to exhibit both short-term and long-term temporal variations that are in general difficult to model. To maximize the utilization efficiency of radio resources, it is critical that these temporal fluctuations in radio signal quality be incorporated into wireless routing decisions. In this paper, we explore the design considerations in leveraging accurate real-time radio channel quality information when making routing decisions. Specifically, we propose a channel characteristics-aware routing protocol (CARP) that (1) uses per-packet transmission time to estimate the effective residual capacity of a wireless link, (2) employs a bandwidth probability distribution model to better approximate a wireless path's capacity profile, and (3) applies multi-path routing to exploit diversity among alternative paths and deliver more robust throughputs despite temporal fluctuations in wireless link quality. We evaluated the performance gains of incorporating each of these mechanisms on a miniaturized multi-hop wireless network testbed- MiNT-m.