Impact of inactivity timer on performance of control plane in LTE core network under burst traffic

This paper proposes a simple EPC queueing model to evaluate the network performance of the control plane in LTE core networks, and to clarify the impact of the parameter for the radio interface, the inactivity timer, on the performance of core networks. The proposed EPC queueing model incorporates the protocol behaviors of state transition in session management, and introduces a parameter, the mixture ratio of batch arrival (MRBA), to represent burst traffic or spike traffic in the input of the queueing model. The network performance is evaluated in terms of loss rate and latency for connection setup. Numerical results show that MRBA substantially affects the performance of a core network. It is also revealed that some values of the inactivity timer locally degrade the performance of a core network depending on the specific conditions of the input traffic.