ARCHITECTING NONCOOPERATIVE NETWORKS

In noncooperative networks users make control decisions that optimize their individual performance measure. Focusing on routing, two methodo logies for architecting noncooperative networks are devised, that impr ove the overall network performance. These methodologies are motivated by problem settings arising in the provisioning acid the run time pha ses of the network. For either phase, Nash equilibria characterize the operating point of the network. The goal in the provisioning phase is to allocate link capacities that lead to systemwide efficient Nash eq uilibria. The solution of such design problems is, in general, counter intuitive, since adding link capacity might lead to degradation of use r performance. For systems of parallel links, it is shown that such pa radoxes cannot occur and that the optimal solution coincides with the solution in the single-user case, Extensions to general network topolo gies are derived. During the run time phase, a manager controls the ro uting of part of the network flow. The manager is aware of the noncoop erative behavior of the users and makes its routing decisions based on this information while aiming at improving the overall system perform ance. We obtain necessary and sufficient conditions for enforcing an e quilibrium that coincides with the global network optimum, and indicat e that these conditions are met in many cases of interest.