Assessing Performance Gains Through Global Resource Control of Heterogeneous Wireless Networks
Abstract: We study the resource allocation and management issues related to heterogeneous wireless systems made up of several radio access technologies (RATs) that collectively provide a unified wireless network to a diverse set of users through co-ordination managed by a centralized global resource controller (GRC). We assume that the user devices are multimodal, which makes it possible for each device to use any available access point (AP)/base station (BS) of a RAT at any given time. Through detailed protocol level simulations performed in ns-2, we show an increase in spectral efficiency of up to 99 percent and an increase in short-term fairness of up to 28.5 percent for two greedy sort-based user deviceto-AP/BS association algorithms implemented at the GRC compared to a distributed solution used in practice today where each user makes his/her own association decision. While the increase in overhead due to re-associations for a centralized solution grows only slightly (by up to 4.1 percent) compared to a distributed solution, we find the performance increase in spectral efficiency and short-term fairness attributes come at the cost of an order of magnitude increase (of up to 794 percent) in energy consumption.