Call dropping performance of the relay station (RS)-first channel access scheme in LTE-Advanced relay networks

Both the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE-Advanced) and IEEE 802.16m rely on relay technique to ameliorate cell edge throughput. Despite the throughput benefit achieved by relay technique, LTE-Advanced relay network is vulnerable to frequent handoffs, which can degrade the dropping performance, an important quality-of-service metric concerning realtime communications. This paper proposes a mathematical model to analyze the call dropping performance of the relay station (RS)-first channel access scheme, which prefers a RS-channel over an eNode-B (eNB)-channel when determining an access channel for a new and a handoff call. Closed-form analytical result is derived for the dropping probability of the RS-first policy and based on the result a numerical study is conducted to evaluate the influences of diverse parameters on the dropping performance. The result obtained in this paper can be availed of to develop appropriate call admission strategies in LTE-Advanced relay networks.