A Client-Driven Approach for Channel Management in Wireless LANs

Abstract

Abstract-We propose an efficient client-based approach for channel management (channel assignment and load balancing) in 802.11-based WLANs that lead to better usage of the wireless spectrum. This approach is based on a "conflict set coloring" formulation that jointly performs load balancing along with channel assignment. Such a formulation has a number of advantages. First, it explicitly captures interference effects at clients. Next, it intrinsically exposes opportunities for better channel re-use. Finally, algorithms based on this formulation do not depend on specific physical RF models and hence can be applied efficiently to a wide-range of in-building as well as outdoor scenarios.We have performed extensive packet-level simulations and measurements on a deployed wireless testbed of 70 APs to validate the performance of our proposed algorithms. We show that in addition to single network scenarios, the conflict set coloring formulation is well suited for channel assignment where multiple wireless networks share and contend for spectrum in the same physical space. Our results over a wide range of both simulated topologies and in-building testbed experiments indicate that our approach improves application level performance at the clients by upto three times (and atleast 50%) in comparison to current best-known techniques.

Distributed spectrum assignment for home WLANs

“…[19] explicitly takes into account interference at the clients of each WLAN. However, it does not provide any optimality guarantee and it requires all the APs to be under a single administrative domain.…”

“…Several approaches exist to efficiently assign channels to nodes in order to increase network performances (see e.g., [15], [16], [19], [20], [23]). In general, when all channels have the same width, the goal is to introduce as much spectral separation as possible between potentially interfering links.…”

Partially Overlapping Channel Assignments in Wireless Mesh Networks

“…First, an existing algorithm [22] was modified which is a centralized greedy-style approach for CA in WLANs using only orthogonal channels with the objective of increasing overall spectrum utilization. The algorithm employs an indicator variable to model the interference in WLANs and the authors have modified this indicator variable to capture not only the orthogonal channels (which was previously the case) but also channels with partial overlap (using their I-factor model).…”

Load Balancing for Dynamic Spectrum Assignment with Local Information for Secondary Users

“…There are also two recent excellent treatments studying games related to CR spectrum allocation by Etik et al [18] and Suris et al [19]. In the different context the semi-centralized or distributed channel allocation has also been studied in the context of ISM-band WLAN-systems [20], [21], [22], [23], [24], [25]. Useful background can be also found from [26], [27], [28], [29], [30].…”