5G Proximity Services-enabled User Equipment

Description

The 5G ProSe-enabled UE is a fundamental component of the 5G Proximity Services (ProSe) framework, defined in 3GPP Release 19 and maintained in Release 20. It represents a user equipment that has the capability to support 5G ProSe requirements and the associated procedures specified in 3GPP TS 23.304. ProSe allows UEs to discover each other and communicate directly, either with or without network coverage, using the 5G radio interface. This capability is essential for public safety, commercial applications, and mission-critical services where direct communication is needed.

Architecturally, a 5G ProSe-enabled UE can operate in several modes: it can perform ProSe discovery (either direct discovery or network-assisted discovery) and ProSe communication (direct or indirect). The UE interacts with the 5G core network (5GC) through the PC5 interface for direct communication and the Uu interface for network communication. The 5G ProSe architecture includes network functions such as the ProSe Function, which manages authorization, provisioning, and policy control for ProSe-enabled UEs. The UE must be authorized by the network to use ProSe services, and it may be provisioned with ProSe policies and parameters.

The UE supports various ProSe procedures, including ProSe discovery, ProSe direct communication, and ProSe UE-to-network relay. ProSe discovery enables a UE to detect other ProSe-enabled UEs in its vicinity. ProSe direct communication allows two or more UEs to communicate directly over the PC5 interface without traversing the network. ProSe UE-to-network relay allows a remote UE to connect to the network via a relay UE. These procedures are essential for extending coverage and enabling group communication.

From a management perspective, the 5G ProSe-enabled UE is managed via the 5G ProSe management object (MO) defined in 3GPP TS 32.277. This MO allows the network to configure ProSe-related parameters on the UE, such as ProSe discovery parameters, ProSe communication parameters, and relay parameters. The MO ensures that the UE behaves according to operator policies and can be dynamically updated.

The 5G ProSe-enabled UE is a key enabler for a wide range of applications, including public safety (e.g., push-to-talk, group communication), commercial services (e.g., social networking, proximity-based advertising), and IoT (e.g., wearable devices, vehicle-to-everything communication). By supporting direct communication, ProSe reduces latency, improves spectral efficiency, and enables new use cases that are not possible with traditional cellular communication. As 5G evolves, the role of ProSe-enabled UEs will continue to expand, especially with the integration of new features like network slicing and edge computing.

Purpose & Motivation

The 5G ProSe-enabled UE exists to enable direct device-to-device communication and discovery within the 5G ecosystem, addressing the limitations of traditional cellular networks that require all traffic to traverse the core network. This is particularly important for public safety and mission-critical communications, where network infrastructure may be unavailable or congested. ProSe allows devices to communicate directly, ensuring reliable and low-latency connectivity even in challenging environments.

Historically, ProSe was first introduced in 4G LTE (Release 12) to support public safety and commercial proximity services. However, 4G ProSe had limitations in terms of flexibility, scalability, and integration with the 5G core. The 5G ProSe-enabled UE builds on these foundations, leveraging the 5G service-based architecture, network slicing, and enhanced QoS to provide more robust and versatile proximity services. It also supports new use cases such as vehicle-to-everything (V2X) communication and industrial IoT.

The 5G ProSe-enabled UE solves the problem of direct communication in scenarios where network coverage is unreliable or where low latency is critical. It also enables new business models, such as proximity-based marketing and social networking, by allowing devices to discover and interact with each other based on their location. By integrating ProSe into the 5G standard, 3GPP ensures interoperability and global adoption, driving innovation in both consumer and enterprise markets.