Section: 4.3.18.3a MPS for Data Transport Service
Content: MPS for Data Transport Service is an on-demand service that may be invoked/revoked by an authorized MPS Service User using a UE with a subscription for MPS (i.e. according to its MPS profile), or using a UE that does not have a subscription for MPS (using methods not in scope of this specification). MPS for Data Transport Service requires explicit invocation. The Service User invokes the service by communicating with an AF. The authorization of an MPS for Data Transport Service request is done by the AF or by the PCRF according to clause 6.1.11.5 of TS 23.203[ Policy and charging control architecture ]  [6]. Upon successful authorization the PCRF performs the necessary actions to achieve appropriate ARP and QCI settings for the bearers (see clause 6.1.11.5 of TS 23.203[ Policy and charging control architecture ]  [6]). NOTE 1: MPS for Data Transport Service can be applied to any APN other than the well-known APN for IMS. MPS for Data Transport Service enables the prioritization of all traffic on the default bearer and other bearers upon AF request. The QoS modification to the default bearer and other bearers is done based on operator policy and regulatory rules by means of local PCRF configuration. NOTE 2: If no configuration is provided, MPS for Data Transport Service applies only to the default bearer. NOTE 3: MPS for Data Transport Service controls the priority of traffic on bearers independent of the application(s) being used. Other mechanisms (e.g., Priority EPS Bearer Service) can be used to control the priority of traffic on other bearers not under control by MPS for Data Transport Service, based on operator policy. For MPS for Data Transport Service, the AF may also create an SDF for signalling priority between the UE and the AF (see clause 6.1.11.5 of TS 23.203[ Policy and charging control architecture ]  [6]). NOTE 4: The network can hide its topology from the AF supporting MPS for Data Transport Service. At the same time, the UE needs to provide its locally known IP address to the AF supporting MPS for Data Transport Service to support Diameter routing to the applicable PCRF. Thus, there can be no NAT of the UE IP address between the PDN-GW and the AF supporting MPS for Data Transport Service.