Description
MCVideo Emergency State (MVES) is a logical and functional state entered by a user's Mission Critical Service Client (e.g., an MCVideo application) and recognized by the network's Mission Critical Server. It is triggered by an explicit user action to initiate an emergency service, most commonly the start of an MCVideo Emergency Private Call (MVEPC). Entering MVES is a pivotal event that alters the operational parameters and network handling for all communications from that user for the duration of the emergency incident.
Architecturally, the state transition is managed collaboratively between the MC Client and the MCVideo Server. When a user triggers an emergency video call, the client application sends a specific service request (e.g., an emergency session initiation request as per TS 24.281) to the MCVideo server. Upon validating the request and beginning call setup, the server acknowledges and confirms the activation of MVES for that user. This state is then maintained in both the client and the server. The client's user interface may change (e.g., displaying a prominent 'EMERGENCY' indicator), and its behavior is modified—for instance, it may automatically accept incoming emergency-related communications or restrict non-emergency actions.
From a network perspective, the declaration of MVES has significant implications. It informs the MCVideo server and, by extension, the core network policies that this user's traffic should be treated with the highest priority, not just for the initial call but for any follow-on communication. This means that even if the initial MVEPC session ends, the user might remain in MVES, and any new video call or data session they initiate could continue to receive emergency-priority QoS (governed by mechanisms like MVEPP) until an authorized person (the user or a dispatcher) explicitly cancels the emergency state. The server manages this state, potentially broadcasting the user's emergency status to other authorized users (like a dispatcher group) and logging all activities for post-incident analysis. Clearing the MVES involves a specific deactivation procedure, returning the user and their services to normal priority levels.
Purpose & Motivation
MVES exists to provide context and persistence to emergency operations beyond a single call session. The problem it solves is the potential fragmentation of emergency response; without a persistent state, a first responder might establish a high-priority MVEPC, but once that call ends, their next communication (e.g., sending a vital image or starting a new call) could inadvertently revert to normal priority, causing dangerous delays. MVES ensures continuity of priority treatment throughout the entire emergency incident.
This concept was motivated by operational protocols from traditional land mobile radio systems, where an 'emergency mode' or 'man-down' state persists until cleared. Translating this to IP-based broadband systems required a standardized, service-layer state machine. MVES addresses the limitation of a purely session-centric QoS model by tying priority to the user's operational status. It provides a clear, unambiguous signal to the entire mission-critical system that a particular user is engaged in a life-critical situation, allowing for coordinated and prioritized support from both the network and other human operators until the situation is formally resolved. It is a key feature for making MCVideo services robust and operationally practical for real-world public safety use.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (116 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-14, normative work from Rel-15.
In Release 15, the MVES (MCVideo Emergency State) function was newly introduced, providing the signaling control for MCVideo emergency calls and emergency alerts as part of the MCVideo service for public safety. This included the definition of specific client internal states such as the MCVideo emergency alert state and MCVideo emergency group call state. The release also introduced support for handling these emergency communications both on-network and off-network using the specified MCVideo call control protocols.
- MCVideo ambient viewing client procedures TS 24.281CR0033
- MCVideo ambient viewing participating MCVideo function procedures and controlling MCVideo function procedures TS 24.281CR0034
- MCVideo ambient viewing general description TS 24.281CR0035
- Usage of MBMS for MCVideo - signaling control TS 24.281CR0037
- Correction to session-type in XML schema for MCVideo Information TS 24.281CR0039
- Fix issues with encoding of IEs in MONP messages for MCVideo TS 24.281CR0046
+ 8 more changes
In Release 16, enhancements to the MCVideo Emergency State (MVES) function included corrections to location schemas and alert elements, along with fixes for emergency upgrade procedures. The release also formally completed IANA registrations for MCVideo parameters. Furthermore, it expanded the scope of emergency support by introducing off-network MCVideo capabilities for both group and private calls.
In Release 17, the MVES function was enhanced with new interconnect procedures for Emergency Alerts, enabling coordinated emergency communications across different MCVideo systems. Additionally, improvements were made to the location XML schema by adding altitude, timestamp, and accuracy attributes for more precise emergency situational awareness. The release also introduced client-side handling for emergency alert area notifications, ensuring users are promptly informed of relevant emergency events.
- Functional Alias usage in MCVideo Call TS 24.281CR0093
- Add altitude, timestamp to MCVideo location XML schema TS 24.281CR0095
- Add preconfigured regroup to MCVideo TS 24.281CR0096
- Control per service authorizations limit for MCVideo service TS 24.281CR0100
- Call control - Restricting MCVideo private communications TS 24.281CR0105
- Emergency alert area notification functionalities handling for MCVideo TS 24.281CR0106
+ 32 more changes
In Release 18, the MVES (MCVideo Emergency State) function was enhanced with new procedures for emergency and imminent peril ad hoc group calls, and for handling emergency alerts to clients affiliating after a group has moved to an emergency alert state. It also introduced support for location information requests from an MCVideo client and updates to location information triggers. Furthermore, the release added clarifications for the conditions of emergency group or alert notifications upon area entry or exit.
- Use of 5G MBS transmission in MCVideo signalling plane TS 24.281CR0199
- Add the description of 5MBS in MCVideo TS 24.281CR0220
- MCVideo support of multiplexing - SDP offers and answers TS 24.281CR0215
- Support MCVideo over 5G ProSe TS 24.281CR0225
- General adhoc group call procedures in single system - Protoc impl for MCVideo TS 24.281CR0221
- Adhoc group call participants modify procedures in single system - protoc impl MCVideo TS 24.281CR0226
+ 35 more changes
In Release 19, enhancements to the MCVideo Emergency State (MVES) function specifically refined the criteria for determining participant lists during an ongoing ad hoc group emergency alert. These modifications also included corrections and enhancements to the handling of SIP messages containing these participant lists for authorized users. The updates further addressed schema corrections and operational procedures to ensure robust functionality for ad hoc group emergency communications.
- Modify list of participants by changing the criteria during an ongoing MCVideo ad hoc group call TS 24.281CR0278
- Adhoc group emergency alert add criteria to the SIP message containing the participant lists sent to the authorised users TS 24.281CR0279
- MCVideo adhoc group call to migrated user TS 24.281CR0280
- Modifying the criteria for determining the participants during an ongoing ad hoc group emergency alert TS 24.281CR0282
- FRMCS_Ph5 Adding reason to leave a session in MCVideo TS 24.281CR0290
- Enhance handling of criteria for ad hoc group communication (MCVideo) TS 24.281CR0267
+ 11 more changes
Explore further
Broader topics and technologies where MVES plays a role.
Defining Specifications
3GPP specifications that define or reference MVES, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 24.281 vj40 | MCVideo Signalling Control Specification | Rel-19 |
| TS 37.579 vi40 | Mission Critical services conformance testing | Rel-18 |