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

In this letter, we propose to use bit rate as another network resource for reducing the blocking probability in wavelength-division-multiplexing networks with nonnegligible transmission degradations. In our proposed scheme, different bit rates are assigned to the connection requests according to the transmission performance. The adaptive bit rate can be achieved by a concatenated code with the commonly used Reed-Solomon RS(255,239) code as the inner code and Golay(23,12) code as the outer code. The concatenated code is simple in operation and it can be used to double the transmission distance with acceptable transmission quality. The performance of our network resource allocation algorithm is checked by simulation in a China Education and Research Network-like network and significant reduction in blocking probability is found.