3PoC: an architecture for enabling push to talk services in 3GPP networks

Push to Talk over Cellular (PoC) is an on-demand resource efficient half-duplex voice communication service, which has gained tremendous popularity but lacks standardization in the 3GPP domain. In this paper we propose and evaluate a 3GPP system architecture for efficient implementation of PoC services in a 3G packet switched network. We focus on the impacts of PoC requirements on 3GPP UTRAN and CN network elements. We illustrate key interfaces and sample signaling message exchange for PoC service. We also evaluate the performance of PoC signaling transfer over the proposed architecture using the NS2 simulator. Our initial findings indicate that a reasonable signaling QoS can be achieved in UMTS based PoC networks.