LTE Advanced Pro

7LLC Service – Proximity Communications

7.1. Introduction

The proximity service (ProSe) enables a new type of link, the sidelink (SL), between mobiles, in addition to the downlink (DL) and uplink (UL) between a mobile and an evolved node base station (eNB).

The proximity service implements two types of communication:

• – device-to-device (D2D) communication;
• – vehicle-to-everything (V2X) communication.

The D2D communication comes in two applications:

• – communication between mobiles related to public safety (e.g. firefighters);
• – communication between mobiles for commercial purposes.

The mobile communication between mobiles related to public security allows the service to be maintained when the eNB entity fails, for example, in a large-scale disaster or when mobiles are no longer covered by the eNB entity.

The distribution of information to nearby terminals is a function introduced for mobile communication for commercial purposes.

In the coverage scenario, the radio access network controls the resources used for the D2D communication. It can assign to a mobile-specific resource or a pool of resources from which the mobile selects. In this way, interference with cellular traffic is avoided.

In the case of the mobile being out of coverage, control over the radio access network is not possible. The mobile uses preconfigured resources, either on the equipment or in the universal subscriber identity module (USIM) of the universal integrated circuit card (UICC).

A special case ...