Dimensioning and optimization of push-to-talk over cellular server

The PoC (Push-to-talk over Cellular) application allows point-to-point, or point-to-multipoint voice communication between mobile network users. The related work over PoC focuses on the performance analysis only and is completely ignorant about dimensioning PoC controller to optimize revenue for service providers. In this paper, we dimension a PoC controller with the assumption that the network grade of service is provided. The on-demand sessions should have access priority over pre-established sessions. A PoC controller should be able to terminate a PoC session based on an optimal timer. Moreover, the number of simultaneous session initiation by a PoC client is also a configurable parameter. We derived relations to provide access priority to special PoC sessions based on available Transmit/Receive Units (TRU) and threshold level. Load staring expressions are reported for a PoC controller using Lagrange multiplier technique. A simple relation to control the PoC session timer is proposed. Finally, the derivation of maximum number of allowable simultaneous session is depicted using two state Markov models. Values have been computed with the corresponding derivation to provide useful insight into the system behaviour. A PoC controller can benefit from these optimal values of our work during busy hour.