A Novel Fault Tolerance Parallel Routing Mechanism with Network Coding in Hybrid Wireless-Optical Broadband Access Network

Survivability is the critical issue in the wirelessoptical broadband access network (WOBAN) since that any failure of network components would resulted in a large amount of traffic interrupted. The previous mechanisms suffer from two key issues. First, they must reroute the interrupted traffic to the backup resources which caused a long recovery time. Second, the deployment of backup fiber could increase the recovery cost. To address these problems, a novel fault tolerance parallel routing mechanism with network coding (FTPR-NC) is proposed in this paper to enhance the survivability. In FTPR-NC mechanism, the original packets are coded to the optimal number of encoded packets which results in the minimum cost of recovery. Then the encoded packet is transferred to the destination node in accordance with the packet allocation scheme which results in the minimum number of encoded packet when recover the original packets by parallel routings. Numerical results show that the proposed FTPR-NC mechanism outperforms the previous mechanism significantly on the performance of average delay. Meanwhile, the FTPR-NC mechanism dramatically decrease the recovery time when a failure occurs.