Description
A Presence Reporting Area (PRA) is a network-defined geographical zone, conceptualized in 3GPP standards to provide a mechanism for reporting a UE's location at a granularity between a single cell and a large Tracking Area (TA). A PRA can be constructed from a list of cells, Tracking Area Identities (TAIs), or evolved NodeBs (eNBs/gNBs), or it can be defined as a geographical shape (e.g., polygon). It is a logical construct maintained by the Core Network, specifically the Mobility Management Entity (MME) in 4G or the Access and Mobility Management Function (AMF) in 5G, often in coordination with the Policy and Charging Rules Function (PCRF/PCF).
How it works involves several key components and procedures. First, the PRA is provisioned in the network, defining its identity (PRA ID), its constituent elements (cells/TAIs), and the reporting triggers (e.g., UE entering the area, leaving the area, or being inside the area). This information can be pushed to the UE or used solely within the network. When a UE's mobility events (like cell changes) align with the configured triggers for a monitored PRA, the Radio Access Network (RAN) or the UE itself (depending on the configuration) generates a report. This report is sent to the core network, which then may forward it to an external Application Function (AF) or use it internally for network optimization.
Architecturally, the PRA functionality spans multiple network nodes. The PCRF/PCF can request the PRA-based reporting for a specific UE as part of policy and charging control, often initiated by an AF's service request. The MME/AMF is responsible for managing the PRA subscription for the UE, including activating, modifying, or deactivating the reporting. It communicates the relevant PRA information to the RAN (eNB/gNB) via S1/NGAP signaling. The RAN then monitors the UE's cell-level location and triggers reports accordingly. In some configurations, the UE can be informed of the PRA and report its own presence, reducing RAN signaling load.
The role of PRA is to provide a flexible, efficient tool for location-aware services. For example, for a localized broadcast service (e.g., an earthquake warning), an AF can request to be notified when UEs enter a PRA corresponding to the affected region, and then initiate a broadcast only in those cells. For mobility optimization, the network can define PRAs around congestion hotspots and use entry reports to trigger load balancing actions. It offers a more targeted alternative to Tracking Area Updates, which cover larger areas and are primarily for network-originated paging, not for application-level location services.
Purpose & Motivation
The Presence Reporting Area was introduced in 3GPP Release 12 to address the growing demand for efficient, network-assisted location services that balance precision with signaling overhead. Prior to PRA, applications requiring knowledge of UE location had limited options: they could rely on imprecise Tracking Area information, burden the network with frequent, fine-grained location requests (e.g., using Cell-ID), or depend entirely on the UE's GNSS (GPS), which consumes UE battery and may be unavailable indoors.
It solves the problem of providing application-relevant location information without incurring excessive network signaling or UE power consumption. PRA allows the network to define an area of interest once and then receive automatic notifications only when relevant mobility events occur, rather than polling the UE's location repeatedly. This event-driven model is significantly more efficient for services that only need to know when a UE crosses a specific boundary, such as geo-fenced advertising, localized emergency alerts, or optimized content caching at the network edge.
Its creation was motivated by the need to enable new business models and network optimization techniques in the LTE-Advanced era and beyond. Operators and service providers sought mechanisms to offer context-aware services. PRA provides a standardized way to meet this need, facilitating lawful interception location reporting, supporting machine-type communication (MTC) location triggers, and enabling core network functions like the Service Capability Exposure Function (SCEF/NEF) to provide location as a service to third-party applications. It represents a shift towards more intelligent, policy-driven mobility management.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (116 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-12, normative work from Rel-15.
In Release 15, the Presence Reporting Area (PRA) function was newly introduced, as indicated by a dedicated Change Request. This release also included specific corrections and clarifications to PRA, such as resolving an Editor's Note on the topic, correcting the `PresenceInfo` data type, and clarifying PRA reporting procedures for the ECM-IDLE state. Furthermore, enhancements were made to enable immediate reporting and to introduce a Presence Reporting Area Node AVP.
- Secondary RAT related data usage reporting TS 23.401CR3267
- Control of Secondary RAT data volume reporting TS 23.401CR3285
- Data volume reporting when secondary RAT is using unlicensed spectrum TS 23.401CR3357
- Data Volume Reporting for Secondary RAT usage TS 32.251CR0499
- Secondary RAT related data usage reporting improvements TS 23.401CR3325
- Secondary RAT related data usage reporting format from RAN TS 23.401CR3326
+ 21 more changes
In Release 16, the Presence Reporting Area (PRA) function was enhanced with clarifications and corrections to event reporting, including the handling of location change reporting to the PCF and the description of the scopes field and presenceStatus attribute. Specific improvements addressed the correct presence condition for event subscriptions and for network slice identifiers (snssai). Furthermore, updates were made to location reporting procedures for multiple cells and to enable periodic PSCell ID reporting.
- Enhancement of network event reporting TS 23.401CR3454
- Enhancement of event reporting information TS 29.508CR0047
- Clarification of MME handling for secondary RAT data reporting TS 23.401CR3581
- Reporting event of EPS FB initiated TS 23.503CR0384
- Corrections for event reporting from the PCF TS 23.503CR0419
- Reallocation of credit reporting to the AF TS 23.503CR0434
+ 11 more changes
In Release 17, the Presence Reporting Area (PRA) function was enhanced to support reporting the initial presence status for a UE when the PRA monitoring is activated. Key corrections were made to the triggering conditions for location change reporting and to immediate PRA reporting procedures. Additionally, the release introduced support for mute reporting and enabled the reporting of available allowed NSSAI when an ImmediateReport is triggered.
- Reporting Change of PDUID by the PCF TS 23.503CR0573
- Support of Mute Reporting TS 29.508CR0132
- Reporting the outcome of the AM Policy request fron the AF TS 23.503CR0650
- corrections for 5GS Bridge Information reporting and subscription TS 23.503CR0714
- report initial presence status for PRA TS 29.507CR0130
- Correction on the condition for location change reporting TS 29.507CR0188
+ 7 more changes
In Release 18, the PRA function was enhanced with new UE reporting capabilities including support for Packet Delay Variation monitoring and reporting, periodicity measurement and reporting for power saving, and the reporting of URSP rule enforcement between SM-PCF and UE-PCF. It also introduced support for time synchronization status reporting and mechanisms for UE location reporting specifically for NB-IoT satellite access. Furthermore, the release completed the reporting procedures for Satellite Backhaul changes and configured NSSAI changes.
- UE reporting implementing conclusions for KI#2 from TR 23.700-85 TS 23.503CR0901
- Support of time synchronization status reporting TS 23.503CR0929
- Forwarding of UE reporting of URSP rule enforcement between SM-PCF and UE-PCF TS 23.503CR0947
- Policy control support for Packet Delay Variation monitoring and reporting TS 23.503CR0955
- Periodicity measurement and reporting for power saving TS 23.503CR0995
- PCRT for UE reporting of URSP rule enforcement for LBO roaming TS 23.503CR1073
+ 32 more changes
In Release 19, the Presence Reporting Area (PRA) function was enhanced with new reporting capabilities for QoS parameters, Available Bit Rate QoS monitoring, and QoS notification events with direction information. It also introduced support for reporting AF request rate limitation information for service data flows and completed the subscription for Satellite Identifier reporting. Furthermore, the release included corrections and clarifications to various reporting procedures, such as QoS monitoring and multiplexed media identification, to improve reliability and feature dependencies.
- Support of relocation reporting for UPF relocation TS 29.508CR0293
- Support of QoS parameters reporting TS 29.508CR0329
- Support of AF request rate limitation information reporting for service data flow TS 29.514CR0716
- Complete the Satellite Identifier reporting subscription TS 29.514CR0747
- Clarification about the feature dependency for QME reporting TS 29.514CR0750
- Update rate limit information reporting TS 29.514CR0752
+ 15 more changes
Explore further
Broader topics and technologies where PRA plays a role.
Defining Specifications
3GPP specifications that define or reference PRA, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 23.203 vj20 | Policy and charging control architecture | Rel-19 |
| TS 23.401 vj50 | Evolved Packet System (EPS) Stage 2 Description | Rel-19 |
| TS 23.503 vk00 | 5G Policy and Charging Control Framework | Rel-20 |
| TS 29.212 vj00 | Gx/Gxx/Sd/St Diameter Protocol | Rel-19 |
| TS 29.507 vj40 | 5G Access & Mobility Policy Control Service | Rel-19 |
| TS 29.508 vj40 | 5G Session Management Event Exposure Service | Rel-19 |
| TS 29.514 vj40 | 5G System; Policy Authorization Service; Stage 3 | Rel-19 |
| TS 29.525 vj40 | 5G UE Policy Control Service Stage 3 | Rel-19 |
| TS 32.251 vj00 | PS Domain Charging Management | Rel-19 |