Wireless Network Coding for Multi Radio Multi Channel Mesh Networks

In wireless networks packets are lost because of queue congestion during high traffic, collisions, hidden nodes, and link failures. The problem of dropped packets becomes more critical in real-time applications, such as video conferences and remote controls. This paper presents a new wireless network coding (WNC) scheme and router detection packet loss (RDPL) algorithm for retrieving packets that are lost in a wireless network. In the WNC scheme, a router combines (encodes) packets originating from the same or different sources and forwards the packets to another router. In the RDPL algorithm, the coding router sends a negative acknowledge to the upper layer routers whenever it receives only one packet or two identical packets. The proposed WNC–RDPL method increases the transmission capacity and packet delivery ratio (PDR). The architecture has been evaluated for one, two, three, and four link failures. The simulation results show that the WNC–RDPL approach obtain 100% PDR gains compared with well-known linear network coding schemes.