Resource-on-demand schemes in 802.11 WLANs with non-zero start-up times

Abstract

Increasing the density of access points is one of the most effective mechanisms to cope with the growing traffic demand in wireless networks. To prevent energy wastage at low loads, a resource-on-demand (RoD) scheme is required to opportunistically (de) activate access points as network traffic varies. While previous publications have analytically modeled these schemes in the past, they have assumed that resources are immediately available when activated, an assumption that leads to inaccurate results and might result in inappropriate configurations of the RoD scheme. In this paper, we analyze a general RoD scenario with N access points and non-zero start-up times. We first present an exact analytical model that accurately predicts performance but has a high computational complexity, and then derive a simplified analysis that sacrifices some accuracy in exchange for a much lower computational cost. To illustrate the practicality of this model, we present the design of a simple configuration algorithm for RoD. Simulation results confirm the validity of the analyses, and the effectiveness of the configuration algorithm.The work of J. Ortín was supported in part by the Gobierno de Aragón (research group T98) and the European Social Fund, in part by the EU H2020 Wi-5 Project under Grant 644262, and in part by the Centro Universitario de la Defensa under Project CUD2013-05. The work of C. Donato, P. Serrano, and A. Banchs was supported by the European Commission in the framework of the H2020-ICT-2014-2 Project Flex5Gware under Grant 671563 and in part by the Madrid Regional Government through the TIGRE5-CM program under Grant S2013/ICE-2919