Abstract
Mission Critical Communications and Services are of a special nature that needs special requirements. Therefore, there are many challenges that face implementing mission critical communication system over commercial mobile communications networks. Signaling of SIP messages in the access technology domain and IMS domain needs enhancement to ensure meeting the mission critical service requirements. LTE, as a broadband technology that is widely deployed nowadays for providing 4G communication networking services, is facing a lot of challenges in terms of its ability to provide multimedia services. And due to the special nature of Mission Critical Systems (MCS) that have stringent requirements for SIP signaling specifically, the need for investigating the SIP signaling performance over LTE based MCS is of great importance. In this paper, the performance metrics for an SIP signaling over LTE-MCS will be defined, and the overall system performance measures were evaluated via discrete event simulator.