Application of MIH for the lightweight deployment of LTE-advanced systems through mobile relaying

Abstract

In a conventional cellular network end users connect directly to a Base Station (BS). Mobile relaying allows establishing an indirect two-hop link between the end user, called Mobile Node (MN), and the BS through a Mobile Relay (MR). This spreads out the cell coverage and increases the cell-edge throughput hence improving fairness among nodes. This article is focused on a Long Term Evolution Advanced (LTE-A) cellular network where MNs and MRs are connected through a Wireless Fidelity (WiFi) ad-hoc connection. It is proposed the use of Media Independent Handover (MIH) signaling to define an efficient dynamic routing mechanism for MR in this framework. The proposed mechanism, called MIH-Driven Relay Selection Mechanism (MIDRES), detects which is the best direct or indirect link with the BS based on information collected using MIH messages. The MNs or MRs send MIH messages when experiencing bad channel conditions, that is detected thanks to predefined thresholds. Then, the BS starts a polling process, again supported by MIH signaling, and performs optimal route selection either through the LTE-A radio interface or through a WiFi ad-hoc interface. This article examines the implementation of this mechanism and obtains the optimal thresholds that maximize operational performance. Moreover, the potential benefit of this LTE-compliant mobile relaying solution is evaluated using a calibrated simulation tool. The results show significant savings in cost of network deployment.