Bandwidth Optimization in Centralized WLANs for Different Traffic Types

Allocating bandwidth between different forms of coexisting traffic (such as web-browsing, streaming and telephony) within a wireless LAN is a challenging and interesting problem. Centralized coordination functions in wireless LANs offer several advantages over distributed approaches, having the benefit of a system overview at the controller. Nonetheless, even with this overview, obtaining a stable configuration of bandwidth allocation for the system is nontrivial. We present, review and compare different mechanisms to achieve this end, and a number of different means of obtaining the configurations themselves. We describe an analytical model of the system under consideration and present two mathematical approaches to derive solutions for any system configuration and deployment, along with an adaptive feedback-based solution. We also describe a comprehensive simulation-based model for the problem. Our investigations demonstrate that a self-adaptive dynamic approach far out-performs any static scheme, and that using a comprehensive mathematical model to produce the configurations themselves confers several advantages.