Spectral efficiency and energy consumption tradeoffs for reconfigurable devices in heterogeneous wireless systems

The proliferation of wireless broadband usage over the last decade has led to the development and deployment of multiple broadband wireless radio access technologies (RATs) such as EVDO, WiMAX, HSPA and LTE. To support the ever-increasing wireless traffic demand, researchers have worked on the concept of an integrated heterogeneous wireless environment that encompasses several of these RATs which makes the resource allocation process more efficient by assigning each user in the system to the best RAT/RATs. In this paper, for such an integrated heterogeneous wireless system, we show the possible gains in spectral efficiency at the cost of increased energy consumption for an unbalanced heterogeneous wireless network deployment scenario. In prior work, based on the assumption that all cellular operators under study were equally well-provisioned, we showed an increase in spectral efficiency of up to 75%. In the research presented in this paper, we assume the coverage of each operator might differ significantly in a given area. With this 'unbalanced' scenario, we show that an ideal, centralized allocation strategy provides an almost linear tradeoff between gain in spectral efficiency (554%) and worst-case increase in energy consumption (615%) for users supporting elastic traffic. © 2012 IEEE.