Modeling diameter protocol in an LTE environment : a method -

Abstract

The Diameter protocol, successor to RADIUS, is the de-facto AAA protocol in LTE networks. However, it acquired and is still acquiring more roles and functionalities, because the protocol was designed with the ability to expand. This expansion in the protocol functionalities led in some cases to signaling storms in the EPC. Our study thus focuses on the effect of Diameter in LTE networks. A mathematical model that estimates Diameter traffic on the S6, Gx, Ro, and Sy interfaces, along with a set of Diameter message pairs exchanged on the interfaces in question, is derived. In addition, the model can be extended in order to study any other Diameter interfaces of interest. Simulations were performed in MATLAB for two cases: fixed UEs and mobile ones. The mathematical results derived from the model and the simulation results were compared, and showed good agreement, with an error range from 3 to 14percent. Furthermore, we conclude from our study that when it comes to UE populations with low average mobility speed, the effects of mobility on signaling are minimal.