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This letter proposes an analytical model to evaluate the collision probability on the Random-Access CHannel (RACH) in Long-Term Evolution systems as a function of the number of user equipment, the number of available preambles, and the Inter–arrival times of the RACH Requests (IRRs) of the average user. The model for the IRR of the average user is obtained from real traffic data captured at the eNodeB of a mobile operator, and is derived by emulating the radio resource control (RRC) state machine for different RRCs Inactivity timer (RRC $_{\text {IT}}$ ) settings. The results of this letter suggest that when RRC $_{\text {IT}}$ is set to a few seconds, a mixture model is more accurate than the Poisson hypothesis both in modeling the IRR and in estimating the RACH performance.

Monitoring operations in today's mobile networks is becoming a more and more challenging task due to the higher bandwidth and technological complexity brought by LTE. The paper summarizes some relevant problems that arose in the tests of LTE equipment carried out at Telecom Italia Lab (TILAB, the R&D center of Telecom Italia), and presents an ongoing project that aims at realizing a flexible hardware/software platform to cope with these problems at reasonable costs. The ultimate goal of this research is to develop a Software Defined Networking (SDN) measurements platform, which permits to easily and dynamically configure the measurement devices involved in the test and monitoring functions according to the requirements defined by the operator. Furthermore, the paper proposes the integration of the designed framework in a realistic lab environment, and discusses the improvements introduced to the actual architecture.