4 General description

22.1533GPPMultimedia priority serviceRelease 19TS

MPS is applicable in EPS and 5GS systems.

MPS provides priority treatment to increase the probability of an authorized Service User’s Voice, Video, Data and Messaging communication being successful. Some form of priority treatment is applied to the MPS invocation and session establishment, and continues to be applied until the MPS session is released. The priority treatment may be applied before the invocation if a greater probability of success in receiving, recognizing, and processing the invocation is needed.

MPS allows qualified and authorized users to obtain priority access to the next available radio channel on a priority basis before other PLMN users, during situations when PLMN congestion is blocking session establishment attempts. In addition, MPS supports priority sessions on an "end-to-end" priority basis.

MPS is intended to be utilised for Voice, Video, Messaging and Data bearer services, including the Data Transport Service, in the Packet-switched (PS) domain and the IP Multimedia Subsystem (IMS). It also involves priority transitioning of MPS service (e.g., Voice) to the CS domain when the network does not support the requested service in the PS domain. MPS sessions for Voice, Video, Data, and Messaging are based on providing priority treatment to the corresponding commercial services offered to the public.

MPS is also intended to be utilized for IoT communications through machine interactions that may not directly involve a human Service User.

MPS includes network functions that fall into the following broad categories:

Service Invocation: The process to recognize and identify a request for an MPS session. An MPS Service Provider network recognizes an MPS invocation based on the presence of an MPS-unique identifier entered by the originating Service User in the service request received by the network from the UE, or based on the subscription profile of the originating UE, or as a regional/operator option the subscription profile of the terminating UE.

NOTE: The option related to “subscription profile of the terminating UE” may not involve end-to-end priority because this option is based on providing priority only in the terminating network based on the terminating UE subscription profile.

Authorization: The process to verify that a Service User is authorized for MPS. This includes capabilities to verify authorization to receive priority treatment in the radio access network and to access the MPS application service (MPS Voice, Video, Data, and Messaging).

End-to-End Priority Treatment: The process of providing priority treatment in all parts of the path, from one endpoint to the other endpoint(s). End-to-end priority treatment includes priority treatment by all MPS capable networks involved in the MPS session path, the origination network and the termination network as well as any transit networks in between.

Invocation-to-Release Priority Treatment: The process of providing priority treatment to all phases of a session, from invocation until release, including all steps in between.

The combination of End-to-End Priority Treatment and Invocation-to-Release Priority Treatment includes both pre- and post-authorization treatment and includes the following aspects:

1) Priority processing of the Service User’s MPS invocation,

2) Admission control and allocation of network resources (including bearer resources) in origination, termination, and transit networks, including handovers,

3) Transport of signaling and media packets,

4) Priority processing within EPS, 5GS and CN, and

5) Processing of the Service Users release of an MPS service session.

Network Interconnection and Protocol Interworking: A Service User’s MPS invocation and session establishment will involve transport and processing, and the end-to-end signaling and media path may traverse multiple MPS Service Provider networks. These end-to-end cases include, but are not limited to:

1) Voice, video, data and messaging services over EPS or 5GS, including signaling for call/session establishment and media;

2) EPS/5GS interworking with the CS domain, including a) calls originated in the CS domain and terminated in EPS/5GS, and b) calls from EPS/5GS to the CS domain;

3) CS Fallback from EPS, for one or both ends of call, with maintenance of existing PS domain MPS services, either in EPS or in a legacy system, e.g., the GPRS Core; and

4) Access to MPS data, video, and messaging services not under IMS control.