Ultra-Dense Heterogeneous Relay Networks: A Non-Uniform Traffic Hotspot Case

Ultra-dense heterogeneous networks (UD-Het- Nets) with non-uniform traffic hotspots are important scenarios for future wireless networks, which, however, impose challenges on efficient framework and algorithm design due to the heavy congestion incurred by massive hotspot users. Considering these challenges, this article first develops a two-layer interference-aware heterogeneous relay network architecture that consists of macro base station networks and ultra-dense relay networks. Particularly, we develop an approach to formulate a QoE-aware optimization problem that enfolds connectivity and delay, both of which are crucial for hotspot users in our framework. Regarding this problem, we further devise a cost-efficient resource allocation algorithm that achieves almost the same performance as the optimal one.