A Local IP Access Mechanism for VoIP Service in LTE Home eNodeB Systems

The need for multimedia communication through wireless media brings development of 4G cellular wireless networks. Long Term Evolution (LTE) is one of 4G standards and specified in 3GPP. In an LTE system, home base station (HeNB) is designed for indoor usage. Since packets are always routed back to the core network before to destination, if two user equipments (UEs) stay in the same HeNB, the routing path is detour and results in longer packet delivery delay, jitters and thus lower data throughput. As a result, the idea of local IP Access (LIPA) was drawn and two solutions have been proposed. However, the two solutions would suffer from poor voice quality in a VoIP application. We propose a novel solution which establishes an additional data radio bearer (DRB) between UE and HeNB to detect local packets. Once local packets are detected, the data radio bearer is then responsible for local packet delivery. Simulation results show that our method outperforms the other two solutions in terms of packet delivery delay and mean opinion score (MOS).