Power control for OSNR optimization in optical networks: a distributed algorithm via a central cost approach

This paper addresses the problem of optical signal-to-noise ratio (OSNR) optimization in optical networks. An analytical OSNR network model is developed for a general multi-link configuration, that includes the contribution of amplified spontaneous emission and crosstalk accumulation. An network OSNR optimization problem is formulated such that all channels maintain a desired individual OSNR level, while input optical power is minimized. An iterative, distributed algorithm for channel power control is proposed, which is shown to converge geometrically to the optimal solution. Convergence is proved for both synchronous and asynchronous operation.