Coordination of autonomic functionalities in communications networks

Future communication networks are expected to feature autonomic (or self-organizing) mechanisms to ease deployment, tune parameters automatically and repair the network. Self-organizing mechanisms are designed as stand-alone entities, even though multiple mechanisms run in parallel in operational networks. An efficient coordination mechanism will be the major enabler for large scale deployment of self-organizing networks. We model self-organizing mechanisms as control loops, and study the conditions for stability when running control loops in parallel. Based on control theory, we propose a distributed coordination mechanism to stabilize the system. In certain cases, coordination can be achieved without any exchange of information between control loops. The mechanism remains valid in the presence of noise via stochastic approximation. Instability and coordination in the context of wireless networks are illustrated with two examples. We are essentially concerned with linear systems, and the applicability of our results for non-linear systems is discussed.