In this paper, we examine the Physical Sidelink Discovery Channel (PSDCH) for out-of-coverage (OOC) Device-to-Device (D2D) Long Term Evolution (LTE) networks using direct discovery for User Equipments (UEs) that are half-duplex. We derive upper bounds for the number of D2D-capable OOC UEs that can share the PSDCH while maintaining a minimum probability of discovery message reception by optimizing the transmission probability threshold and exploiting the fact that the upper bound is nearly linear with respect to the number of resources in the discovery resource pool. The simple, closed form approximate bound that results from our analysis can be used by network operators and public safety agencies as they plan the deployment of the National Public Safety Broadband Network (NPSBN). We validate our results using Monte Carlo simulations in MATLAB and the ns-3 simulation tool.
2019 IEEE Global Communications Conference (GLOBECOM)