Description
Proximity-based Services (ProSe) is a comprehensive 3GPP architecture defined across multiple technical specifications (e.g., TS 22.278, 23.280, 23.281) that enables Device-to-Device (D2D) discovery and direct communication. It allows User Equipment (UE), such as smartphones or IoT devices, to detect the presence of other ProSe-enabled devices in close geographic proximity and establish a direct data path, either using licensed spectrum (under network control) or independent of network coverage. The architecture involves several key network functions, including the ProSe Function in the core network, which manages authorization, provisioning, and discovery assistance, and the ProSe Application Server, which supports service-level operations.
ProSe operates through two primary procedures: ProSe Direct Discovery and ProSe Direct Communication. In Direct Discovery, a UE can announce its presence or listen for announcements from other devices using predefined codes. This can be network-assisted, where the network helps assign discovery resources and verify permissions, or autonomous, where devices use pre-configured resources. Direct Communication establishes a one-to-one or one-to-many data connection between devices. For in-coverage scenarios, the E-UTRAN or NG-RAN allocates radio resources for the direct link, ensuring efficient spectrum use and minimal interference with conventional cellular traffic. For out-of-coverage or partial-coverage scenarios, such as in public safety operations, devices can use pre-allocated resources to communicate directly, forming ad-hoc networks.
The technology leverages the underlying LTE or 5G NR radio access but introduces new sidelink interfaces (e.g., PC5 interface for direct communication between UEs). The ProSe Function authenticates users for ProSe services, provides them with necessary parameters (like discovery codes or radio resource configurations), and may relay discovery requests. For communication, the data plane bypasses the core network user plane, reducing latency and backhaul load. ProSe is integral to enabling critical services like public safety communications during network outages, commercial applications like social networking discovery, and vehicular communication (which later evolved into V2X services), representing a shift from purely infrastructure-centric to more distributed, device-centric connectivity models.
Purpose & Motivation
ProSe was created to address several key limitations of traditional cellular architecture, where all communication is routed through base stations and core network nodes. This model introduces latency, consumes backhaul resources, and fails entirely when network infrastructure is damaged or unavailable. The primary motivation was to support mission-critical public safety communications, where first responders need to communicate directly during disasters. Prior to ProSe, public safety relied on separate, dedicated land mobile radio systems, which lacked the high data rates and rich services of cellular networks.
Another driving purpose was to enable new commercial and social proximity-based applications, such as device discovery for social media, local file sharing, or targeted advertising. This created opportunities for network operators to offer new services and offload traffic from the core network, improving overall capacity and efficiency. The technology also laid the groundwork for more advanced direct communication paradigms, most notably Vehicle-to-Everything (V2X) communication, which is critical for autonomous driving and intelligent transportation systems.
The introduction in Release 14 marked a significant evolution from earlier D2D concepts studied in Releases 12 and 13, providing a fully standardized service layer and network architecture. It solved the problem of how to integrate direct device communication into a licensed spectrum, operator-managed environment, ensuring control, security, and billing capabilities. ProSe thus bridges the gap between the reliability and manageability of cellular networks and the flexibility and resilience of ad-hoc peer-to-peer networks.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (30 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-14, normative work from Rel-15.
In Release 15, new ProSe capabilities were introduced to support mission critical services, including Forward Error Correction (FEC) and header compression for Mission Critical services over MBMS. These enhancements were defined alongside the existing ProSe framework for ProSe Discovery and ProSe Communication, which includes both direct E-UTRA and WLAN communication paths.
- FEC for mission critical services TS 23.280CR0043
- Header compression for MC services over MBMS TS 23.280CR0058
- Correction to behaviour of SN for security handling This CR was not implemented as is was not based on the latest version of the spec. TS 38.423CR0082
- Correction of Core Network Type Restriction This CR was not implemented as is was not based on the latest version of the spec. TS 38.423CR0104
In Release 16, ProSe introduced new capabilities for Mission Critical services, including criteria-based automatic group affiliation and de-affiliation. It also added functional alias alternative addressing for MCX services, enabling automatic activation and deactivation of these aliases based on a user's location. These enhancements provided more dynamic and context-aware group communication for ProSe-enabled UEs.
- Location information reporting based on functional alias TS 23.280CR0203
- Criteria based automatic group affiliation and deaffiliation TS 23.281CR0123
- MCVideo client performs automatic activation and deactivation of functional aliases based on location TS 23.281CR0132
- Criteria based automatic group affiliation and de-affiliation TS 23.379CR0202
- MCPTT client performs automatic activation and deactivation of functional aliases based on location TS 23.379CR0216
- Spelling of ProSe TS 23.280CR0167
+ 3 more changes
In Release 17, the ProSe function was enhanced with clarifications for its use in off-network Mission Critical (MC) services, specifically for off-network MCPTT calls and MCVideo communications. These updates provided more precise operational guidelines for these direct, proximity-based communications. No new fundamental ProSe communication paths or discovery types were introduced in this release based on the provided materials.
- Add call forwarding based on manual input for MCPTT private calls TS 23.379CR0247
- Add call forwarding based on manual input for MCPTT private calls TS 23.379CR0249
- Introduction of NR Multicast and Broadcast Services TS 38.423CR0491
- Clarifications on the use of ProSe in off-network MCVideo communications TS 23.281CR0150
- Clarifications on the use of ProSe in off-network MCPTT calls TS 23.379CR0276
- Correction of RACH-based SDT Stage 3 TS 38.423CR0782
+ 2 more changes
In Release 18, the ProSe function introduced a new Call Release Reason code as part of the PES-based Call Disconnect procedure. This addition provides a specific mechanism for conveying the reason for a call release within proximity-based services communications. The release also included corrections to the XnAP protocol, specifically to the Conditional Handover Time Based Information IE.
In Release 19, the key enhancements for Proximity-based Services (ProSe) focused on refining Mission Critical (MC) group communication services. Specifically, the release introduced continuous updates to the participant list for both MCVideo and MCPTT ad hoc group communications, where the list is dynamically maintained based on defined criteria. Additionally, access to these MC services by external applications was restricted, and improvements were made to multi-talker control by enabling priority-based floor overriding.
- Priority-based floor overriding when using multi-talker control TS 23.280CR0552
- Potential IMS limitations based on deployment scenarios after migration TS 23.280CR0600
- Corrections of AI/ML-based CCO for XnAP TS 38.423CR1686
- Correction on UE Based TA Measurement ID assignment for inter-CU (SCG) LTM TS 38.423CR1700
- Removing external applications access to MC services TS 23.280CR0604
- Add statement to MCVideo ad hoc group communication about continuous updates to a group participant list based on criteria TS 23.281CR0245
+ 1 more changes
Explore further
Broader topics and technologies where ProSe plays a role.
Defining Specifications
3GPP specifications that define or reference ProSe, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 22.278 vj00 | Evolved Packet System Service Requirements | Rel-19 |
| TS 23.280 vk10 | Common Architecture for Mission Critical Services | Rel-20 |
| TS 23.281 vk10 | MCVideo Functional Architecture and Flows | Rel-20 |
| TS 23.379 vk00 | MCPTT Functional Architecture | Rel-20 |
| TS 38.423 vj10 | Xn Application Protocol (XnAP) specification | Rel-19 |