A Research On The Algorithm Of Deflection Routing In Optical Burst Switching Networks

There is an explosive growth trend of Internet business, which leads to rapid increase of network bandwidth available for IP data business. In recent years, the improvement of dense wavelength division multiplexing (DWDM) technology has made it possible that a single optical fiber can serve more than one hundred channels and transmission bandwidth reach dozens to hundreds of Tb/s, which meets the demands for Internet bandwidth business. Optical fiber communication will play an important role in the future society of information. The optical data network that is based upon the technology of IP over DWDM not only sufficiently uses huge band-width resource of optical fiber, but also has the flexibility of IP service. Hence it will become the tendency of future communication network.Optical Burst Switching is one of the best practical methods to realize optical transport network. It makes BDP as the basic unit of exchange, and adopts a special approach that BDP and BCP are transmitted on the separated signal channel, with the advantages of moderate size, high performance, simple to complement and so on. It is widely considered to be a way of realizing the all optical network communication with wide prospect. How to avoid or reduce high rate of lost data and end-to-end delay caused by sudden random data conflicts is one of the key technologies determining whether OBS network is practical or not. In the paper, we have a comprehensive and systematic study of OBS network architecture. Then we analysis several network resources competition settlement mechanism, and make conclusions of the basic principle, as well as its advantages and disadvantages. The improved thought of deflection routing solution is given in this paper. New strategy about the"random"deflection process of traditional deflection routing is proposed. This is, first we choose the three shortest routes from source node to destination node in orderly. Then we calculate the total hops of the two conflict bursts after deflecting from current node to destination node. Take the way that burst with less hop count is to deflect or to retransmit, and the burst with more hop count is to transmit directly on the current path in order to solve the burst contention problem in OBS. The network simulation tool of OPNET 10.0 is used in this paper to compare the results. Experimental data shows that it can reduce data loss in OBS networks using deflection routing. And this improvement takes less delay than traditional deflection routing and highly improves the performance of network system.