Comparison of Spectrum Sharing Techniques for IMT-A Systems in Local Area Networks

The explosive growth of mobile communications on one hand and the overly crowded and expensive spectrum on the other hand have fueled hot debates on spectrum sharing techniques, anticipating fundamental changes in spectrum regulation. A key point of the discussions has been the need for empirical tests and validation of even the simplest spectrum sharing proposals already available. In this paper, inspired by IEEE 802.11 WLANs, the authors employ carrier sense multiple access with collision avoidance (CSMA/CA) in an LTE-Advanced framework and compare the achieved performance with that of an ordinary LTE-Advanced system employing static frequent reuse schemes. The analysis is performed by means of system level simulations in Local Area networks where the e-NodeBs (eNB) may be randomly placed without any prior considerations to minimize inter-cell interference. Average and cell-edge user throughput results show that the contention based approach, despite its beautiful simplicity, wastes resources due to random back-off timers and hidden nodes. In nearly all cases, well known frequency reuse alternatives are more interesting options.