Enhanced floor control protocol for PoC application in data packet voice communication

Push-to-Talk over Cellular (PoC) is a one-to-one or one-to-many Push-To-Talk (PTT) service designed to work over the cellular network. In the PTT, a participant may speak as soon as he/she has obtained the permission through pushing a “talk” button. The typical telephone setup delay is avoided. In the traditional floor control protocol defined in the Open Mobile Alliance standard (FCP-OMA) for PoC, at any time only one participant is permitted to speak. The permitted speaker is totally “deaf” and the listeners are fully “dumb” until the speaker releases or is revoked the floor. In this article, we propose an enhanced floor control protocol (EFCP) for PoC application in a packet voice scenario where full-duplex communications can be supported. The proposed protocol is divided into two categories: EFCP-M and EFCP-NM depending on whether media mixing is needed or supported. Through a queuing model, we compare the performance of EFCP against FCP-OMA. Experimental results show that our scheme can significantly reduce the probability that floor requests are denied and the expected waiting time in queue.