What is the 5G multimedia priority service (MPS)?
According to the 3GPP, the response to emergency situations (e.g., floods, hurricanes, earthquakes, terrorist attacks) depends on the communication capabilities of public networks. In most cases, emergency responders use private radio systems to aid in the logistics of providing critically needed restoration services. However, certain government and emergency management officials and other authorized users have to rely on public network services when the communication capability of the serving network may be impaired, for example due to congestion or partial network infrastructure outages, perhaps due to a direct or indirect result of the emergency situation.
“Multimedia Priority Service [MPS], supported by the 3GPP system set of services and features, is one element creating the ability to deliver calls or complete sessions of a high priority nature from mobile to mobile networks, mobile to fixed networks, and fixed to mobile networks,” 3GPP said.
MPS is a 3GPP feature designed to enable NS (National Security) or EP (Emergency Preparedness) subscribers to make priority calls or data session on a Service Providers network, particularly at times of congestion.
According to Cisco, MPS allows priority access to system resources to Service Users, creating the ability to deliver or complete sessions of a high priority nature. Service Users are government-authorized personnel, emergency management officials and/or other authorized users. MPS supports priority sessions on an “end-to-end” priority basis. MPS includes signalling priority and media priority.
Cisco also noted that MPS provides the ability to invoke, modify, maintain and release sessions with priority, and deliver the priority media packets under network congestion conditions.
“All MPS-subscribed UEs get priority for QoS Flows (for example, used for IMS signalling) when established to the DN that is configured to have priority for a given Service User by setting MPS-appropriate values in the QoS profile in the UDM. Service Users are treated as On Demand MPS subscribers and not On Demand MPS subscribers, based on regional/national regulatory requirements. On Demand service is based on Service User invocation/revocation explicitly and applied to the media QoS Flows being established. Not On Demand MPS service does not require invocation and provides priority treatment for all QoS Flows only to the DN that is configured to have priority for a given Service User after attachment to the 5G network,” Cisco said.
The networking company also said that priority treatment for MPS includes priority message handling for Mobility Management procedures. Priority treatment for MPS session requires appropriate ARP and 5QI setting for QoS Flows according to the operator’s policy.
“MPS priority mechanisms can be classified as subscription-related and invocation-related. Subscription related mechanisms are divided into — always applied and conditionally applied. Invocation-related mechanisms are divided into — for mobile originated SIP call/sessions, for mobile terminated SIP call/sessions and for Priority PDU connectivity services.”
3GPP noted that MPS is applicable in EPS and 5GS systems.
“MPS provides priority treatment to increase the probability of an authorized Service User’s Voice, Video, and Data communication session 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,” 3GPP said.
“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,” 3GPP added.