Description
RSLPP (Ranging and Sidelink Positioning Policy) is a policy control framework defined within the 5G System (5GS) to govern the use of sidelink-based ranging and positioning services. Sidelink refers to direct device-to-device communication, bypassing the network infrastructure, as used in technologies like NR Sidelink (SL) for Vehicle-to-Everything (V2X) and public safety scenarios. The RSLPP provides the rules and authorization mechanisms that determine when, how, and under what conditions two or more User Equipment (UEs) can perform ranging (distance measurement) or collaborative positioning using sidelink resources.
Architecturally, the RSLPP is managed by the Policy Control Function (PCF), a core network entity responsible for policy and charging control. The PCF generates RSLPP policies based on subscriber profiles, service requirements, and network conditions. These policies are then provisioned to the relevant UEs via the Access and Mobility Management Function (AMF) or directly over the sidelink control channels. The policy itself contains parameters such as authorized peer devices, permissible ranging methods (e.g., Time-of-Arrival, Round-Trip-Time), allowed frequency and duration of ranging sessions, geographic areas where ranging is permitted, and required security credentials.
Operationally, when a UE intends to initiate a ranging session with another UE, it must first evaluate the locally stored RSLPP. The policy dictates if the request is permitted. If authorized, the UE uses sidelink signaling (e.g., via the Sidelink Control Information (SCI)) to coordinate the ranging procedure with the peer UE. The actual ranging measurement can utilize physical layer signals like Positioning Reference Signals (PRS) transmitted over the sidelink. Results may be processed locally or reported back to a Location Management Function (LMF) for enhanced accuracy. The RSLPP ensures these operations do not interfere with other sidelink traffic, adhere to regulatory constraints (e.g., privacy), and consume resources efficiently.
Its role in the network is critical for enabling advanced location-based services in decentralized scenarios. In V2X, vehicles can accurately determine relative positions for collision avoidance without constant GNSS reliance. In public safety, first responders can locate team members in obscured environments. RSLPP provides the necessary governance to make these services reliable, scalable, and secure within the 5G policy framework, integrating sidelink capabilities into the broader network service architecture.
Purpose & Motivation
RSLPP was created to address the growing need for precise relative positioning between devices in direct communication scenarios, particularly within the 5G V2X and IoT ecosystems. Prior to Release 18, sidelink communication (introduced for data exchange in Rel-16/17) lacked a standardized policy mechanism for coordinating positioning activities. Devices could perform ad-hoc ranging, but this led to potential issues: uncoordinated use could congest sidelink resources, measurements might be unreliable without agreed protocols, and there were no formal authorization controls, raising security and privacy concerns.
The motivation stems from the evolution of 5G towards supporting advanced collaborative applications. Vehicle platooning, drone swarm coordination, and augmented reality interactions require devices to know their relative positions with high accuracy and low latency. While GNSS provides absolute location, it is often insufficient in urban canyons, indoors, or for precise relative distancing. Sidelink-based ranging offers a complementary, direct measurement method. However, without a policy framework, such services could not be reliably managed or monetized by network operators. RSLPP provides this management layer, allowing operators to control and offer ranging as a certified service.
It solves the problem of integrating ad-hoc device-centric positioning into the operator-managed 5G policy and charging control architecture. By defining a formal policy, it ensures ranging services are provided only to authorized subscribers, in authorized contexts, using authorized methods. This prevents misuse, optimizes radio resource usage, and enables service differentiation. It also facilitates compliance with regional regulations on location data privacy. RSLPP thus bridges the gap between decentralized sidelink operations and centralized network policy control, enabling scalable, commercial-grade ranging and positioning services.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (290 CRs across 6 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, the RSLPP (Ranging and Sidelink Positioning Policy) function was newly introduced as a component of UE policy information, which is used for access selection. This addition was part of the architectural enhancements to support ranging-based services and sidelink positioning as defined in the specifications. The policy framework for its management is encompassed within the broader UE policy control function provided by the PCF.
- Addition of Reflective QoS Timer in PDU session related policy information TS 23.503CR0005
- UE policies granularity and UE assistance for policy evaluation TS 23.503CR0011
- Update of UDR policy related subscription TS 23.503CR0021
- Corrections to description of session management related policy enforcement TS 23.503CR0025
- Clarification on UE policy configuration TS 23.503CR0044
- Correction on Policy Control Request Triggers TS 23.503CR0046
+ 35 more changes
In Release 16, the RSLPP (Ranging and Sidelink Positioning Policy) function was introduced as a new component of UE policy information for access selection, as defined within the policy and charging control framework. This addition specifically enabled policy control for new ranging-based services and sidelink positioning capabilities. The release also included related enhancements, such as new UE policy control request triggers for V2X communications and procedures for N2 PC5 policy management to support these new positioning and sidelink services.
- Access and mobility related policy information for 5G-RG TS 23.503CR0236
- Update to Policy Framework for TSC TS 23.503CR0310
- Introduction of background data transfer policy information in URSP TS 24.526CR0043
- Specifying and adding reference for V2X Policy TS 24.526CR0052
- NR PC5 unicast security policy provisioning TS 24.587CR0003
- Inconsistent security policy during PC5 unicast link modification procedure TS 24.587CR0093
+ 53 more changes
In Release 17, the RSLPP function was enhanced by extending UE policy control to specifically support ProSe-based services and ProSe U2N relay, as indicated in the CR titles "Extending UE policy control for ProSe based services" and "UE policy control to support ProSe U2N relay." This allowed the PCF to provision updated UE policy information, which includes RSLPP rules for access selection, to the UE to govern these new sidelink and positioning-related capabilities.
- BSF enhancement on PCF Discovery for dynamic AM policy TS 23.503CR0506
- Access and mobility policy control functionality to enable dynamic change of AM Policies TS 23.503CR0520
- Policy control based on satellite backhaul information TS 23.503CR0539
- ProSe Policy TS 23.503CR0533
- Policy control of data rate per network slice TS 23.503CR0552
- Policy control enhancement for local notification TS 23.503CR0587
+ 61 more changes
In Release 18, the Ranging and Sidelink Positioning Policy (RSLPP) function was newly introduced as part of UE policy information for access selection. Key enhancements included specifying the policy and its reference, extending the Requested UE policies Information Element with an indicator for Ranging/SL Positioning policies, and defining message updates for V2X communication procedures to support ranging and sidelink positioning.
- NWDAF- assisted URSPs introduced in policy decision TS 23.503CR0769
- Policy control for dynamic satellite backhaul TS 23.503CR0788
- DN Performance Analytics usage in PDTQ policy TS 23.503CR0799
- Policy update to support policy control enhancements for multi-modal services TS 23.503CR0835
- Updates on PDU session related policy information TS 23.503CR0871
- VPLMN Specific Offloading Policy for HR-SBO TS 23.503CR0925
+ 81 more changes
In Release 19, the main novelty for RSLPP is its formal introduction and definition as a component of UE policy information, used for access selection. This is specified alongside clarifications to the sidelink positioning service request procedure and the required QoS for positioning the located UE(s). The release thus integrates RSLPP into the policy control framework for managing ranging and sidelink positioning policies.
- Minimize number of UE and AM Policy Associations TS 23.503CR1288
- Local Offloading Policy to support Local Handling of Edge Computing TS 23.503CR1348
- KI#1 Clarification on Local Offloading Policy TS 23.503CR1401
- PCF use of QoS and policy assistance information analytic TS 23.503CR1303
- Support of the minimize number for the UE Policy TS 29.513CR0561
- UE and AM Policy Association control based on UDM Subscription Data TS 29.513CR0562
+ 25 more changes
In Release 20, the Ranging and Sidelink Positioning Policy (RSLPP) function was introduced as a new component of UE policy information for access selection, as defined within the policy and charging control framework. This addition specifically enables policy control for new services related to ranging and sidelink positioning, which are architectural enhancements detailed in the supporting specifications. The release thereby expanded the scope of UE policy control to govern how user equipment selects access for these advanced positioning and direct communication services.
- Policy control based on abnormal user plane traffic analytics and traffic pattern analytics TS 23.503CR1599
- Service Adjustment based on Exposure - Policy TS 23.503CR1600
- Adding BDT, PDTQ and UE policy control for network energy saving TS 23.503CR1612
- Policy control based on new Abnormal User Plane Traffic Analytics TS 23.503CR1613
- Correction on QoS and policy assistance analytics TS 23.503CR1627
Explore further
Broader topics and technologies where RSLPP plays a role.
Defining Specifications
3GPP specifications that define or reference RSLPP, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 23.503 vk00 | 5G Policy and Charging Control Framework | Rel-20 |
| TS 24.514 vj30 | Ranging & Sidelink Positioning in 5GS | Rel-19 |
| TS 24.526 vj30 | UE Policies for 5GS; Stage 3 | Rel-19 |
| TS 24.587 vj30 | V2X Services Protocols for 5G System | Rel-19 |
| TS 29.513 vj40 | 5G PCC Signalling Flows & QoS Mapping | Rel-19 |
| TS 29.525 vj40 | 5G UE Policy Control Service Stage 3 | Rel-19 |