Modeling X2 backhauling for LTE-advanced and assessing its effect on CoMP coordinated scheduling

Many LTE-Advanced algorithms and protocols rely on node coordination and cooperation to reduce power consumption, increase spectral efficiency and improve cell-edge performance. Functions such as Coordinated Multi Point, Network Assisted Handover, etc., require a standard connection among nodes to support their operations. The LTE X2 interface meets the above requirements and allows operators to connect nodes for both rel-8 and more advanced (e.g rel-13) functionalities. In this work we describe the modeling of X2 within the SimuLTE system-level simulator. Most research works assume an ideal X2 connection, with null delay and infinite bandwidth. However, the X2 delay and bandwidth do affect the behavior and performance of the aforementioned algorithms. Thus, using CoMP Coordinated Scheduling as a case-study to test X2 functionalities, we show how X2 round-trip delay affects the performance of the CoMP scheduler.