A Double Link Failures Protection Mechanism Via Non-Systematic Diversity Coding

With the development of communication technology and network scale increa-sing,the network failure probability increased.Now,WDM optical network is widely for operators of the core network,the reliability of the WDM optical network is more and more attention.The link failure is one of the most prone to failure in network fault,the occurrence of multiple link failures can not be ignored.In existing link failure protection method,p-Cycle protection method is known as a very good optical network protection mechanism and is widely used,but its failure recovery rate is slow.Non-systematic diversity coding is a coding based recovery technique which offers near-hitless restoration with a competitive spare capacity requirement with respect to other techniques.Non-systematic diversity coding technology through make the original data by a simple XOR operation get coding data,and then through many transmission channel to transmit the original data and the encoded data,these original data come from several transmission channels with a same destination node.When a link failure occurs,destination node directly decode the data received which include the original data and the encoded data to recover the failure data.Because it does not need to put damaged business automatic switching to the backup resources,there is no switching time and can realize sub-millisecond recovery time.We propose a double link failures protection mechanism based on non-systematic diversity coding for double link failures in different network traffic models(static traffic and dynamic traffic).Among them,the connection request of the static traffic model is known.In the network running process,the state of network topology and the traffic state in the network are kept constant.The state of dynamic traffic model are changing.In the process of network operation,network topology remains the same but the traffic between network nodes occur randomly,traffic in accordance with the time in order to reach the network.In this paper,the core of the double link failures protection mechanism based on non-systematic diversity coding is proposed:using an ILP integer linear programming strategy to effectively utilize the redundant resources for the traffic to establish the work path and the protection path,which make the traffic on the link can be recovered quickly when a link failure occurs.So that the network traffic are not affected,and can provide better reliability guarantee of the network.Simulation results show,whether in the static business model or the dynamic business model,in the recovery of the double link failure,the protection method based on non-systematic diversity coding has significantly faster speed than the p-Cycle protection method.