The Research Of Survivability Based On Service Characteristic In Optical Networks

With the rapid development of optical fiber communication, the capacity of optical networks rise continuously, the transmission speed of single wavelength has reached lOGbit/s. Along with the high capacity, the problem of reliability arises:the very high transmission rate could lead to tremendous data loss when failures occur. Therefore, the survivability has become a crucial aspect in the research of optical networks.As one of the most important core supporting technologies of the next generation of high-speed Internet, the optical networks must be able to transmit the traditional voice service, data service and multimedia services simultaneously. Usually, different types of services have different reliability requirements. For example, tele-surgery requires much higher reliability, while entertainment video has relatively lower demand for reliability. Therefore, providing differentiate survivability based on the requirement of services is the necessity of service diversity on the optical networks. Moreover, the level of reliability is often proportional to the cost of protection resource. High reliability is at the cost of high resource redundancy. So, providing differentiate survivability, namely, allocating more protection resource for the services that have higher reliability requirements, and allocating less protection resource for those who have relatively lower reliability requirements, could help to allocate resources to more productive uses.In light of the different reliability demands of services, we study the survivability of optical networks at length. The main work and contributions are in the following three aspects: (1) We analyze the factors that influence the reliability of optical networks theoretically when shared-path protection is used. On this basis, we put forward a new parameter named service failure probability (SFP) and give its specific calculation method. By the parameter, we could verify the effectiveness of the differentiated quality of protection (QoP) schemes.(2) We put forward a novel differentiated QoP scheme named maximum shared scheme (MS scheme), which could allow backup resource sharing among services of different classes. The simulation results show that MS scheme could achieve smaller blocking probability, smaller redundancy and better resource utilization ratio compared with conventional QoP scheme.(3) In order to improve the spectrum resource efficiency of flexi-Grid optical networks, we propose max-shared backup resource mechanism which employs ergodicity to search the spectrum resource with maximum backup resource sharing degree, and design dynamic load balancing mechanism which considers the backup resource sharing degree. The simulation results show that both of them can effectively improve network resource efficiency.