Analysis of HWMP-ETX Routing in Wireless Mesh Networks

Wireless Mesh Network is one of the budding technologies in wireless networks. Routing in WMN is complicated and unpredictable than wired network, due to unstable link states and interference between neighbor routers. Since WMN is supporting hybrid architecture, a primitive metric like hop count is not efficient to route the information in the network. The Expected Transmission count (ETX) is radio based metric and it reveals the link conditions in the form of delay, loss of packets and bandwidth etc. It uses cross layer approach to direct the data by considering asymmetric nature of wireless links in WMN and captures the link state through the number of retransmissions. Thus ETX forwards the data based on link quality (or state) and provides effective communication between routers. Hybrid Wireless Mesh Protocol (HWMP) is based on IEEE 802.11s and it is prominent protocol for hybrid WMN. The authors aspire to provide effective communication in WMN using link state based metric ETX. This paper discusses about the HWMP with ETX (HWMP-ETX) and analyses the performance of WMN using end-to-end delay and good put parameters. The results show that considerable improvement exists in all the above mentioned parameters by using HWMP-ETX than HWMP with hop count.