Description
The Multimedia Priority Service (MPS) is a 3GPP-defined service that provides preferential treatment to multimedia sessions initiated by authorized users, such as government officials, first responders, and critical infrastructure personnel. Its architecture is integrated into the core network functions, primarily the Policy and Charging Control (PCC) framework. When a user with MPS subscription initiates a session, the network identifies the request via subscription data and applies priority policies. The key components involved include the Home Subscriber Server (HSS) or Unified Data Management (UDM) for storing MPS subscription profiles, the Policy Control Function (PCF) for authorizing and enforcing priority policies, and the Session Management Function (SMF) in 5G (or PGW in 4G) for implementing these policies during session establishment and bearer management.
MPS works by marking the service request with a specific Allocation and Retention Priority (ARP) value and Quality of Service (QoS) Class Identifier (QCI) that indicate high priority. During network congestion, sessions with lower priority may be preempted or blocked to ensure resources are available for MPS sessions. The PCF plays a central role by determining the authorized priority level based on user profile and network conditions, then communicating this to the SMF and User Plane Function (UPF). The UPF then applies the corresponding packet forwarding treatment, ensuring low latency and guaranteed bandwidth for the prioritized media streams.
In the radio access network, MPS influences Radio Resource Management (RRM). The base station (gNB in 5G, eNB in 4G) receives the QoS parameters for the prioritized bearer and schedules radio resources accordingly, giving precedence to MPS traffic over non-priority traffic. This end-to-end priority handling spans from the user equipment through the RAN and core network to the destination, which could be within the same network or in a peer network via interconnection. MPS is defined for both IP Multimedia Subsystem (IMS)-based services like Voice over LTE (VoLTE) and non-IMS services, ensuring broad applicability for critical communications.
Purpose & Motivation
MPS was created to address the critical need for reliable communication for authorized personnel during emergencies, disasters, or network congestion events. Traditional best-effort networks cannot guarantee service availability when demand spikes, which can hinder emergency response and national security operations. The service ensures that vital communications from government, military, and public safety users are maintained even when public networks are overloaded, a scenario common during natural disasters or major public events.
Historically, priority services existed for circuit-switched voice (e.g., Government Emergency Telecommunications Service), but with the migration to all-IP networks like LTE and 5G, a standardized mechanism for prioritizing multimedia sessions (including voice, video, and data) became necessary. 3GPP introduced MPS to provide a consistent, interoperable framework across operators and borders. It solves the problem of service degradation or denial for critical users by defining a standardized profile and network procedures that mandate priority treatment across all network layers, from radio scheduling to core network resource allocation.
The motivation extends beyond national security to include essential services like healthcare, utilities, and transportation during crises. By formalizing MPS in 3GPP specifications, it enables global roaming for priority users and ensures that multi-vendor network equipment can interoperate to support the service. This standardization is vital for cross-border emergency cooperation and for providing a predictable quality of service for authorized entities in any network conditions.
Release Timeline
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (101 CRs across 6 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, a key enhancement for Multimedia Priority Service (MPS) was the introduction of the capability to store the MPS indicator in the non-volatile memory of the mobile device. This specifically applies when the MPS subscription information is stored in the UE, where its membership in a special access class (for E-UTRAN/EPC) or Access Identity 1 (for 5GS) is used for priority radio access during network congestion. This stored indicator enables the UE to invoke priority treatment for session establishment without relying solely on network-provided signaling during registration.
- Storing of MPS indicator in non-volatile memory of mobile TS 24.501CR0123
In Release 16, key enhancements for Multimedia Priority Service (MPS) included defining its applicability within Standalone Non-Public Networks (SNPNs) and specifying the handling of MPS sessions by the P-CSCF. The release also introduced procedures for ensuring priority treatment for Mobile Terminated sessions, thereby extending end-to-end priority support to cover both session origination and termination scenarios.
In Release 17, the Multimedia Priority Service (MPS) was significantly expanded to include formal support for the Data Transport Service (DTS) and introduced new authorization and session upgrade capabilities. Key enhancements now allow for upgrading an established non-MPS session, such as an MMTEL voice call, to an MPS session, and provide additional authorization functionality specifically for MPS for DTS. The release also added mechanisms for the attestation of authorized MPS priority markings and extended priority treatment to cover end-to-end paths involving enterprise networks.
- Common MPS Voice, Video and Data updates based on TR 22.854, MPS Phase 2 Feasibility Study TS 22.153CR0041
- MPS service specific updates based on TR 22.854, MPS Phase 2 Feasibility Study TS 22.153CR0042
- Attestation of Authorized MPS Priority Markings TS 22.153CR0045
- Addition of requirements to upgrade an established MMTEL voice call to MPS TS 22.153CR0046
- TR 22.953 Updates based on TR 22.854 MPS Phase 2 Feasibility Study TS 22.953CR0003
- Multimedia Priority Service (MPS) Phase 2 support for Data Transport Service TS 23.203CR1133
+ 28 more changes
In Release 18, the Multimedia Priority Service (MPS) was significantly enhanced to provide comprehensive support for non-3GPP WLAN access to both the EPC and 5GC. This included new specifications for priority treatment during WLAN registration/attach procedures, transport priority, and congestion exemptions to ensure end-to-end priority sessions. The release also expanded MPS interactions with supplementary services and defined consistent MPS and MCS indicators for use across both 3GPP and non-3GPP accesses, including in Equivalent SNPN scenarios.
- MPS when access to EPC/5GC is WLAN (MPS_WLAN) TS 22.153CR0049
- MPS and Supplementary Services Interactions TS 22.153CR0055
- MPS for WLAN NAI augmentation TS 23.003CR0693
- MPS when access to 5GC is WLAN TS 23.501CR3745
- General MPS for Supplementary Services TS 24.173CR0150
- MPS for WLAN EPC congestion exemptions TS 24.302CR0754
+ 26 more changes
In Release 19, the Multimedia Priority Service (MPS) was significantly expanded to include comprehensive priority treatment for messaging services. This includes new support for MPS in IMS Immediate Messaging, IMS Session-based Messaging, and SMS over NAS procedures, with specific enhancements for paging priority and provisioning via interfaces like Rx, Cx, N5, and SCEF. The release also introduced an exemption for MPS from energy limitation controls and provided clarifications for the MPS-subscribed UE definition.
- MPS for Messaging services TS 22.153CR0056
- MPS for Messaging when access is WLAN TS 22.153CR0061
- Support of MPS priority for Messaging TS 23.203CR1139
- Support of MPS priority for IMS Immediate Messaging and IMS Session-based Messaging TS 23.228CR1419
- MPS support for MO and MT SMS over NAS procedure TS 23.272CR0975
- MPS support for Messaging TS 23.501CR5499
+ 24 more changes
In Release 20, the MPS (Multimedia Priority Service) function was extended to specifically support scenarios where access to the EPC or 5GC is provided via satellite networks. This enhancement ensures that authorized Service Users, including those utilizing IoT devices through machine interactions, can receive priority treatment for session establishment and maintenance even when connected through satellite access. The update integrates MPS capabilities into satellite access architectures, applying the existing mechanisms for priority treatment across the end-to-end session path in these new scenarios.
- MPS when access to EPC/5GC is satellite TS 22.153CR0071
Explore further
Broader topics and technologies where MPS plays a role.
Defining Specifications
3GPP specifications that define or reference MPS, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 22.153 vk00 | Multimedia Priority Service (MPS) requirements | Rel-20 |
| TS 22.261 vk30 | 5G System Service Requirements | Rel-20 |
| TS 22.278 vj00 | Evolved Packet System Service Requirements | Rel-19 |
| TR 22.854 vh10 | Feasibility Study on Multimedia Priority Service - Phase 2 | Rel-17 |
| TR 22.862 ve10 | Critical Communications Feasibility Study | Rel-14 |
| TR 22.953 vj00 | Multimedia Priority Service Feasibility Study | Rel-19 |
| TS 23.003 vj50 | Numbering, addressing and identification in 3GPP | Rel-19 |
| TS 23.203 vj20 | Policy and charging control architecture | Rel-19 |
| TS 23.216 vj00 | SRVCC Architecture Enhancements | Rel-19 |
| TS 23.228 vj50 | IMS Stage-2 Service Description | Rel-19 |
| TS 23.272 vj10 | CS Fallback in EPS | Rel-19 |
| TS 23.333 vj00 | MRFC-MRFP Mp Interface Requirements | Rel-19 |
| TS 23.501 vk00 | 5G System Architecture Stage 2 | Rel-20 |
| TS 23.503 vk00 | 5G Policy and Charging Control Framework | Rel-20 |
| TS 23.700 vk00 | XR Services Application Enablement Layer | Rel-20 |
| TS 23.854 vb00 | Multimedia Priority Service (MPS) Enhancements | Rel-11 |
| TS 24.173 vj00 | Multimedia Telephony Service and Supplementary Services in IMS | Rel-19 |
| TS 24.302 vj00 | Access to EPC via non-3GPP networks; Stage 3 | Rel-19 |
| TS 24.368 vj40 | NAS Configuration Management Object | Rel-19 |
| TS 24.501 vj50 | 5G NAS Protocols Specification | Rel-19 |
| TS 24.502 vj20 | 5G Core Access via Non-3GPP Networks; Stage 3 | Rel-19 |
| TR 26.941 vj01 | 5G Media Slicing Extensions | Rel-19 |
| TR 26.950 vj00 | Surround Sound in 3GPP Services Study | Rel-19 |
| TS 29.122 vj40 | T8 Reference Point for Northbound APIs | Rel-19 |
| TS 29.162 vj00 | IMS-IP Network Interworking | Rel-19 |
| TS 29.163 vj00 | Interworking between 3GPP IM CN and CS networks | Rel-19 |
| TS 29.165 vj10 | Inter-IMS Network to Network Interface (NNI) | Rel-19 |
| TS 29.212 vj00 | Gx/Gxx/Sd/St Diameter Protocol | Rel-19 |
| TS 29.213 vj20 | PCC Signalling Flows and QoS Mapping | Rel-19 |
| TS 29.214 vj20 | Policy and Charging Control over Rx | Rel-19 |
| TS 29.228 vj20 | Cx and Dx Interface Signaling Flows | Rel-19 |
| TS 29.232 vj00 | Mc Interface Protocol Profile | Rel-19 |
| TS 29.238 vj00 | H.248 Profile for IBCF-TrGW Interface | Rel-19 |
| TS 29.292 vj00 | IMS Centralized Services (ICS) Interworking | Rel-19 |
| TS 29.332 vj00 | MGCF-IM-MGW Interface Protocol (Mn) | Rel-19 |
| TS 29.333 vj00 | MRFC-MRFP Mp Interface Protocol | Rel-19 |
| TS 29.334 vj00 | IMS-ALG to IMS-AGW Interface Protocol | Rel-19 |
| TS 29.500 vj50 | 5GC Service Based Architecture Specification | Rel-19 |
| TS 29.513 vj40 | 5G PCC Signalling Flows & QoS Mapping | Rel-19 |
| TS 29.514 vj40 | 5G System; Policy Authorization Service; Stage 3 | Rel-19 |
| TS 29.536 vj30 | NSACF Service Based Interface Protocol | Rel-19 |
| TS 29.562 vj40 | HSS Services for IMS & GBA Interworking | Rel-19 |
| TS 29.809 vc00 | Diameter Overload Control Study | Rel-12 |
| TS 29.890 vg00 | CT3 5G System Technical Report | Rel-16 |
| TR 29.949 vj00 | VoLTE IMS Roaming Architecture & Procedures | Rel-19 |
