DARA: Delay-Aware Routing Algorithm in a Hybrid Wireless-Optical Broadband Access Network (WOBAN)

Hybrid wireless-optical broadband access network (WOBAN) is a promising architecture for future network operations. Recently, the wireless part of WOBAN has been gaining increasing attention and early versions are being deployed as a municipal access solution to eliminate the wired backhaul to every wireless router. This architecture saves on network deployment costs because fiber (or wiring) does not need to extend to the end user, and it extends the reach of emerging optical access solutions, e.g., passive optical network (PON)-based access solutions. However, a major research opportunity exists in developing an efficient routing algorithm for the wireless front end of WOBAN. We propose and investigate the characteristics of "delay- aware routing algorithm (DARA)" that minimizes the average packet delay in the wireless front end of a WOBAN. We model wireless routers as queues and predict wireless link states periodically. Our simulation experiments show that DARA achieves better load balancing and less congestion compared to tradional approaches such as minimum-hop routing algorithm (MHRA) and shortest- path routing algorithm (SPRA). In addition to minimizing the delay, DARA also improves the average hop count compared to the predictive throughput routing algorithm (PTRA), a popular protocol used in several deployments for the wireless front end of a WOBAN.