Distributed [Formula Omitted]-Optimal User Association and Cell Load Balancing in Wireless Networks

• Published in: IEEE/ACM transactions on networking Vol. 20; no. 1; p. 177
• Main Authors: Kim, Hongseok, de Veciana, Gustavo, Yang, Xiangying, Venkatachalam, Muthaiah
• Format: Journal Article
• Language: English
• Published: New York The Institute of Electrical and Electronics Engineers, Inc. (IEEE) 01.02.2012
• Subjects: Associations; Load; Studies; Wireless networks
• ISSN: 1063-6692; 1558-2566
• DOI: 10.1109/TNET.2011.2157937

In this paper, we develop a framework for user association in infrastructure-based wireless networks, specifically focused on flow-level cell load balancing under spatially inhomogeneous traffic distributions. Our work encompasses several different user association policies: rate-optimal, throughput-optimal, delay-optimal, and load-equalizing, which we collectively denote [Formula Omitted]-optimal user association. We prove that the optimal load vector [Formula Omitted] that minimizes a generalized system performance function is the fixed point of a certain mapping. Based on this mapping, we propose and analyze an iterative distributed user association policy that adapts to spatial traffic loads and converges to a globally optimal allocation. We then address admission control policies for the case where the system is overloaded. For an appropriate system-level cost function, the optimal admission control policy blocks all flows at cells edges. However, providing a minimum level of connectivity to all spatial locations might be desirable. To this end, a location-dependent random blocking and user association policy are proposed.