CIF: Small: Cooperation in networks: a quantitative study

California Institute Of Technology, Pasadena CA

Investigators

Abstract

This project addresses the study of cooperation in distributed networks, first through the study of simple structures that isolate dedicated resources for global or local cooperation and then directly in general networks. The work is organized into three thrusts. The first thrust employs a global facilitator that has access to all messages in the network and can transmit a rate-R description of these messages to all nodes. Bounding the capacity of such a network as a function of R gives a first-order estimate of the minimal cost and maximal benefit of cooperation in a given network. In the second thrust, we move from global to local models of cooperation to understand how much of the cooperative advantage can be achieved using smaller groups of cooperators. The final thrust studies the implementation and approximation of the most successful cooperation strategies from the earlier thrusts for use in wireless, sensor, and wired networks; here the rate employed to enable cooperation shares the same network resources as the capacity it aims to increase. Example networks demonstrate large potential benefits in communication system performance through the use of strategies that employ cooperation among the communicating devices. Performance improvement is here measured as an increase in the amount of information that can be reliably delivered through a communication network. Increasing rate through cooperation may allow more users to simultaneous communicate or each user to communicate at an increased rate in a given network. This project aims to develop the theoretical foundations of cooperation-based communication strategies and to help guide the design of communication protocols that realize the benefits of cooperation in practice.