Drizzle: Cooperative Symbol-Level Network Coding in Multi-Channel Wireless Networks
Errors are inherently present in unreliable wireless channels. The primary challenge in designing error control protocols in the MAC or physical layer is to effectively maximize achievable throughput in wireless networks even when unpredictable and time-varying errors exist. Network coding has been successfully applied to improve throughput in IEEE 802.11-based wireless networks with a shared broadcast channel. In state-of-the-art physical layer designs in multi-channel wireless networks (such as IEEE 802.16 WiMAX), however, the convenience of a shared wireless broadcast channel to perform opportunistic listening no longer exists, and Hybrid ARQ (HARQ) is the predominant error control protocol in the physical layer, rather than plain ARQ in IEEE 802.11 MAC.