Concatenated code-based bit rate adaptation for blocking probability reduction in WDM networks

We propose to use bit rate, another network resource, adaptively for reducing the blocking probability in WDM networks with non-negligible transmission degradation. Different bit rates are assigned to different connection requests according to the transmission performance. One way to achieve the adaptive bit rate is by using a concatenated code with RS(255,239) code as the inner code and Golay(23,12) code as the outer code. The concatenated code is simple, but still powerful, making it possible to double the transmission distance with acceptable transmission quality. The performance of our network resource allocation algorithm with bit rate adaptation is checked by simulation in a CERNET-like network and significant reduction in blocking probability is found with minor loss in the total network usage.