Association Optimization in Wi-Fi Networks

Abstract

Densification of Wi-Fi networks has led to the possibility for a station to choose between several access points (APs). On the other hand, the densification of APs generates interference, contention and decreases the global throughput as APs have to share a limited number of channels. Optimizing the association step between APs and stations can alleviate this problem and increase the overall throughput and fairness between stations. In this paper, we propose an original solution to this optimization problem based on two contributions. First, we present a mathematical model for the association optimization problem based on a realistic share of the medium between APs and stations and among APs when using the 802.11 DCF (Distributed Coordination Function) mode. Then, we introduce a local search algorithm to solve this problem through a suitable neighborhood structure. This approach has the benefit to be tuned according to the CPU and time constraints of the WLAN controller. Our evaluation, based on simulations, shows that the proposed solution improves the overall throughput and the fairness of the network.

Performance analysis of video on demand in an IEEE 802.11p-based vehicular network

“…Typically, these works rely on mono-dimensional or two-dimensional Markov chains whose solutions may not necessarily be trivial. Aside from these finegrained models, more macroscopic models for IEEE 802.11 that deliver estimates for the mean throughput attained by a node (for a given level of priority) have been proposed [10,11,12,13]. In this paper, we too consider a general and versatile model that eases its application to the case of a VoD platform.…”

“…Knowing the maximum achievable throughput of each vehicle, we aim at estimating their attained throughput while taking into account the CSMA/CAbased sharing of the radio channel between vehicles, which mostly ensures fairness in the number of channel accesses among the vehicles (and not so much the duration of those access). To do that we rely on the formula proposed by Amer et al [10], which is derived from previous works [11,12,13]. Denoting the attained throughput of vehicle i by B i , and assuming that RSUs have always frames waiting to be sent to their associated vehicles, we have:…”

Association Optimization in Wi-Fi Networks based on the Channel Busy Time Estimation

“…• Access based Fairness [5]: stations associated to the same AP have the same opportunity of service in saturated mode. It is denoted AbF in the figures.…”

“…Most of the existing solutions to optimize associations propose solutions that aim to improve the overall network throughput and/or the fairness between stations in a saturated scenario [5][6][7]. The saturated scenario corresponds to a case where devices (stations and/or APs) have always a frame to send.…”

Association optimization based on access fairness for Wi-Fi networks

“…This paper is an extended version of [20]. Compared to [20], this new version includes, in addition to a new Related Work section, a more detailed version of our local search algorithm, a comparison of the proposed heuristic with the optimum solution and several versions of our heuristic with different initial configurations along with the computing times, a comparison of our solution with time-based fairness solutions, and a more detailed performance evaluation part with new scenarios including realistic and variable packet sizes extracted from a real traffic trace, non saturated networks and TCP traffic. The paper is organized as follows.…”