Impact of HARQ Retransmission on VoLTE Call Blocking in Cellular LTE

Voice over LTE (VoLTE) has been one of the main revenue generating service for Long Term Evolution (LTE) operators. Any error in the wireless communication systems may result in loss of voice packets leading to poor quality of transmission. To be able to handle errors in the communication system Third Generation Partnership Project (3GPP) has recommended the use of Hybrid Automatic Repeat reQuest (HARQ) scheme for reliable voice communication in an LTE network. However, to achieve reliability HARQ considers retransmission of packets that require more radio resources. This may affect the availability of radio resources due to which one of the network Quality of Service (QoS) measure that is call blocking may get affected. In this paper, we have used a Physical Resource Block (PRB) based Markov model to investigate the impact of HARQ retransmissions on VoLTE call blocking performance in a cellular LTE network.