A model for combined user premises/local exchange dynamic bandwidth assignment in broad-band communication networks

A model is proposed of a two-level control structure for the dynamic allocation of bandwidth to different users and different services in the access area of a multiservice network. Essentially, decisions on traffic scheduling within an assigned bandwidth budget are taken locally and independently at the customers´ premises, following a simple time-invariant randomized strategy, on the basis of the local state information. All customers´ flows are multiplexed at a service center or local exchange onto a digital pipe. The service center periodically reassigns each customer´s capacity share on the basis of global state information at the intervention time. The scope is to compensate for the suboptimality and complete decentralization of the local strategies, without overriding local decisions. The capacity reallocation has to minimize a performance index consisting, for instance, in a weighted sum of expected queue lengths of queuable traffic (e.g. data packets) and blocking probability for nonqueuable traffic (voice or video). Some aspects of this problem are discussed that pertain also to structures other than the one described. For the structure treated, a procedure is outlined for solving the optimization problem