Device-to-Device Communications; Functional Prospects for LTE-Advanced Networks

TLDR

Device‑to‑device communication offers new service opportunities and lightens eNB load for short‑range, data‑intensive peer‑to‑peer traffic, and LTE‑Advanced’s fast, high‑resolution resource management supports this capability. The study investigates the feasibility of adding device‑to‑device communication as an underlay to LTE‑Advanced, addressing key functional blocks and integration with the LTE SAE architecture. The authors propose a dedicated radio bearer for D2D, controlled by the eNB for session setup and resource allocation, allowing use of non‑allocated or partially reused time‑frequency resources under eNB‑controlled power constraints, and evaluate feasibility and range via simulations in two scenarios. Simulations show that modest interference increases make practical‑range D2D feasible, and higher interference tolerances further extend the range.

Abstract

In this paper the possibility of device-to-device (D2D) communications as an underlay of an LTE-A network is introduced. The D2D communication enables new service opportunities and reduces the eNB load for short range data intensive peer-to-peer communication. The cellular network may establish a new type of radio bearer dedicated for D2D communications and stay in control of the session setup and the radio resources without routing the user plane traffic. The paper addresses critical issues and functional blocks to enable D2D communication as an add-on functionality to the LTE SAE architecture. Unlike 3G spread spectrum cellular and OFDM WLAN techniques, LTE-A resource management is fast and operates in high time-frequency resolution. This could allow the use of non-allocated time-frequency resources, or even partial reuse of the allocated resources for D2D with eNB controlled power constraints. The feasibility and the range of D2D communication, and its impact to the power margins of cellular communications are studied by simulations in two example scenarios. The results demonstrate that by tolerating a modest increase in interference, D2D communication with practical range becomes feasible. By tolerating higher interference power the D2D range will increase.