Assessing performance gains via the use of global resource controller for realistic heterogeneous wireless networks

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 multi-modal, which makes it possible for each device to use the Access Point (AP)/Base Station (BS) of any available RAT at any given time. Through detailed protocol level simulations performed in ns-2, we show an increase in spectral efficiency of up to 99.2% and an increase in instantaneous fairness of up to 28.5% for two greedy sort-based user device-to-AP/BS association algorithms implemented at the GRC compared to a distributed solution where each user makes his/her own association decision.