Getting the most of WiFi Mesh Networks with 802.16 Mesh Emulation

Currently deployed wireless mesh networks are based on 802.11, WiFi, technology, which is not efficient in multihop scenarios. We present a method, which emulates 802.16 mesh networks over 802.11 hardware. The method works by embedding 802.16 packets into 802.11 broadcast packets and padding the 802.11 broadcast payload, so that the broadcasts are aligned to 802.16 TDMA frame boundaries. The method requires only software changes on the nodes using 802.11a for mesh communications. This means that the mesh networks installed with 802.11a hardware today can be upgraded with a software patch to take advantage of Quality-of-Service available in 802.16. We use ns2 simulations to show the performance of the 802.11 based mesh networks with the embedded 802.16. We show that the hybrid system can achieve throughputs in multiples of what is possible with 802.11 hardware alone. First, the efficiency of the new system is significantly higher than the efficiency of 802.11 based systems, because we use broadcast packets. Second, the new system eliminates unnecessary collisions in the wireless channel since it takes advantage of scheduled wireless access with 802.16 mesh coordination function.