Impact of ARQ protocols on QoS in 3GPP systems

Traffic transmission over the radio channel requires appropriate techniques to preserve information integrity while maintaining the desired quality of service (QoS) and energy constraints. We focus on a possible configuration of the automatic repeat request (ARQ) protocol defined in the Third Generation Partnership Project (3GPP) technical specifications. A Markov model is developed in order to study the protocol behavior as channel characteristics change. Through this model, we evaluate the impact of the 3GPP ARQ scheme on the QoS of traffic services such as data file transfer and IP telephony. In the case of data transfer, a tradeoff between loss probability and energy efficiency is derived. In the case of IP telephony, we investigate the possibility of guaranteeing low maximum delay and low jitter by adopting the ARQ protocol as an error-recovery scheme.