Service discovery protocols in D2D-enabled cellular networks: Reactive versus proactive

Device-to-Device (D2D) communication, which allows access services offered by nearby devices bypassing the base station, has been regarded as an essential component of the emerging 5G mobile networks. Many advantages can be provided by this direct communication paradigm such as high data rate, traffic offloading, range extension, as well as proximity services and social networking. In such a context, service discovery approaches need to be investigated. In this paper, we propose two protocols for service discovery, namely, reactive (pull) discovery and proactive (push) discovery in infrastructure-coordinated D2D networks. The protocol overhead is calculated and numerical results are provided in order to compare these two protocols. Performance evaluation and simulation results show that the reactive protocol performs better when there are few D2D users whereas the proactive protocol is preferable if the D2D communication demand is high.