LTE-Advanced enhancements for self-backhauled LTE-U small cells: An Addis Ababa case study

The heterogeneous deployment of high-power macro cells and low-power small cells is expected to become the most common approach for operators to meet the increasing demand for capacity in high traffic areas, such as, dense urban hotspots. Furthermore, the recent proposals for operating Long Term Evolution (LTE) networks in the unlicensed spectrum bands (LTE-U) is being considered as an approach for providing additional spectrum for dense small cell deployments. However, the implementation of affordable and flexible small cell backhaul links remains challenging. To that end, self-backhauling the small cells via the existing macro cells as interesting approach, but has limited capacity compared to traditional dedicated backhaul links. In this paper, we investigate possible performance enhancements through the use of LTE-Advanced enhancements, specifically: coordinated multipoint and carrier aggregation (CA), to relax the downlink backhaul capacity bottleneck for self-backhauled LTE-U small cells. We study this proposed approach through system simulations of a selected realistic deployment scenario in a busy area of Addis Ababa. The results of the simulation campaign demonstrate that deployment of self-backhauled LTE-U small cells in dense urban hotspots can provide notable throughput gains, particularly for the case CA enhancements in the small cell backhaul links.