Multi-Layer Mobility Load Balancing in a Heterogeneous LTE Network

This paper analyzes the behavior of a distributed Mobility Load Balancing (MLB) scheme in a multi-layer 3GPP (3rd Generation Partnership Project) Long Term Evolution (LTE) deployment with different User Equipment (UE) densities in certain network areas covered with pico cells. Target of the study is to evaluate MLB in terms of efficient pico cell utilization and macro layer load balancing (LB). The analysis focuses on video streaming traffic due to specific service characteristics (e.g. play-out buffer delay/jitter protection) that might make any mobility performance degradation transparent to the end user performance. Results have shown that the proposed MLB scheme can significantly improve the overall network resources utilization by eliminating potential load imbalances amongst the deployment layers and consequently enhance user experience. However this occurs at the cost of increased Radio Link Failures (RLF), a fact that might be critical for further applying MLB in real-time conversational services without additional mobility optimization and interference management techniques.