Motivation for Interference Management Sample Clauses

Motivation for Interference Management. Limited by their coverage area due to their low transmit power, small cells in HetNets are not exploited sufficiently for their potential to enhance network ca- pacity [44] [45]. This is simply because of the high power disparity between these nodes and the macro base stations. The adverse effect of small cells not draw- ing enough traffic is practically double-edged since macro users also suffer the unavailability of sufficient resources. To this end, one can easily conclude that a mechanism needs to be in place to balance the load amongst macro and small cell base stations in a HetNet for an optimal low power cell utilisation. The concept of range extension (RE) first initiated for LTE, has been proposed to balance the load between TPs in a HetNet [32]. Both cell splitting gain and the user QoE due to a more balanced load, are significantly increased through RE. However, optimal cell association is victimised as a result, as not all users will be connected to the base station with the highest link quality [46]. To extend the coverage of small cells, a positive bias is considered. When the difference in signal strength measured by the user terminal from the macro and nearby small node falls below this bias value, an association to the small cell is triggered, adding higher radius coverage contours around the low power nodes. Therefore, the bias values considered dictate the HO boundaries. It is readily deduced that enhanced performance in HetNets owes itself to determining optimal HO boundaries to avoid small cell radio link failure, in co-channel deployments [34]. Consequently, users in the extended coverage areas suffer strong macro interference affecting the robustness of data and control signal transmission links to these users. To allow for RE, macro interference can be handled either through terminal interference cancellation or base station coordination [30]. The main purpose of enhanced Inter-Cell Interference Coordination (eICIC) techniques is to leverage cell splitting gains through RE in HetNets weeding out the interference sources.