Selection of UE relay considering QoS class for public safety services in LTE-A network

Introduction of Device-to-Device (D2D) communication in public safety (PS) environments has been well investigated by 3rd Generation Partnership Project (3GPP). The main target is to provide communication services to user equipments (UE) in the disaster struck area with the help of ordinary UEs over D2D links. UE-relaying is one of the most important application of D2D communication especially in PS environment. While selecting this type of relay, several factors have to be considered prior to the selection process. Previously, only transmission rates were considered for the selection of UE relay on the basis of received signal strength. We propose a UE relay selection scheme in this article taking into account the quality of service (QoS) class. For that, we consider two important factors which greatly affect the communication process specially in cellular networks; data rates and radial velocity. We use weighted sum model as a tool for selecting most appropriate UE relay. The efficiency of the relay selection process is also increased and we evaluate the performance with the help of system level simulations.