In advanced D2D communication, a single radio resource can be reused among multiple groups which want to communicate with each other if the interference incurred between groups is tolerable.
Hence, we can increase the spectral efficiency and the number of the simultaneous connection by utilizing D2D communication in 5G.
Moreover, since the data is directly transmitted and not going through the core network, the end-to-end latency can be considerably reduced.
Therefore, advanced D2D communication is quite well aligned with IoT services as shown in Figure 25.
The cars can communicate with each other to exchange the information for safety alarm and infotainment without cellular base station.
The home appliances communicate with each other for home automation service.
Many objects in proximity region can be connected to each other so that IoT services can be accomplished.