Feasibility Study for the LTE-Advanced System

DC (Dual Connectivity) and D2D (Device to Device) are two most promising methods to address huge traffic challenges in extreme dense network. In this paper, we investigate the researches and developments on DC and D2D in 3GPP (Third Generation Partnership Project). DC refers to the operation where some UE consumes radio resources provided by at least two different network points connected with non-ideal backhaul. We detail all the four deployment scenarios of DC, i.e., macro and small cells on the same carrier frequencies, macro and small cells on different carrier frequencies that can be split into two sub-scenarios, and only small cells on one or more carrier frequencies. Then we explain the reason why control plane and user plane architecture are designed in the status quo. As to D2D, we design a general procedure about its discovery and communication establishment. At last, we analyze the pros and cons after introducing these two technologies into the existing wireless cellular network.