QoS and Protection of Wireless Relay Nodes Failure Using Network Coding

In general, node protection in a communication network guarantees the traffic flow from source to destination. Traditional protection schemes in wired networks introduce either resource-hungry solutions such as the (1+1) protection scheme or a delay and interrupt to the network operation as in the (1:N) protection scheme. Node protection using network coding could solve the above issues. But the existing research efforts are mostly concentrated on wired networks and not much research has been conducted on wireless mesh networks (WMNs). Implementing the traditional (1+1) protection scheme in wireless networks increases the capital cost and resources cannot be fully utilized. On the other hand, the design and implementation of the (1:N) protection scheme in wireless networks for greater value of N (more than 3) is very difficult. Network coding is a promising technique for relaying traffic and node protection in a wireless network. In multihop wireless networks, very few research efforts are concentrated on node protection schemes using network coding and no reports have been published on measuring the Quality of Service (QoS) performance of node protection using network coding. In this paper, first we introduce a protection scheme for a single relay node failure for WMNs using network coding. We measure the QoS performance, e.g., packet delivery ratio (PDR), latency and jitter, for a single relay node failure with and without our protection scheme. Next, we extend the same protection scheme against two relay node failures and compare QoS performance with two relay failures and no failure. The results show that the QoS performance of protection against single relay node failure and two relay node failures are very close to the no failure scheme, while the network reliability increases due to the protection mechanism.