Efficient routing and wavelength assignment in optical networks

Abstract

The tremendous growth of internet traffic and multimedia applications is in domains such as video broadcast, commercial and high definition TV that requires huge bandwidth transport facilities in the network. The need of huge capacity and long distance transmission are satisfied only through the optical network. In the existing optical network, fiber is entirely used for transmission of signal. A convincing number of researches have been done over the last few years to provide more functionality at the optical level, which leads to the next generation intellectual optical networks. These networks make use of optical routing of signals, along with optical transmission. This has motivated the research on routing and wavelength assignment to reduce the blocking probability along with the development of fault tolerant environment network, which can tolerate high bandwidth endto-end optical connections. To provide the routing mechanism for long distance data transmission and in order to achieve a reduced blocking probability in any network, an alternate path decision routing algorithm is developed. The Alternate Path Decision Algorithm (APDA) works on the principle of dynamic routing method. The routing decision takes place at each node. APDA provides control channel management, traffic engineering, path verification, path property correlation and fault management to maintain and manage the path connection. The control channel management maintains control channels between nodes to interchange signaling, routing and management messages. The control channel may be in-band while coupled with a data-bearing channel and out-of-band while having separate control network. Many controlchannels are possible to act simultaneously. Capability parameters negotiate for each channel separately.The traffic engineering mechanism must be provided to an acceptable performance guarantee, along with a required capacity in the network under usual operating condition. The channel connectivity is maintained by the exchange of hello packets.