Functional model for application plane for an MC system over EPS & 5GS
Audio MCPTT Call Performance
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 6.15 "MCX Service requirements specific to on-network use - Audio MCPTT call performance"
6.15 Audio MCPTT call performance
6.15.1 General overview
Meeting the KPIs defined in the following subclauses is based on a number of factors, including the selection of appropriate protocols, minimizing messaging, the backhaul technology used, and appropriate configuration of the deployed network. The corresponding requirements are intended to convey the resulting KPIs when all of those factors are taken into account. For example, where there is significant backhaul delay, that delay is expected to be added to the KPIs.
6.15.2 General requirements
[R-6.15.2-001] The architecture and protocols providing the MCPTT Service shall be designed in a way to eventually allow a deployed network to meet the KPIs specified hereafter (subclause 6.15.3.2 and subclause 6.15.4.2).
6.15.3 MCPTT access time and mouth-to-ear latency
6.15.3.1 General overview
For MCPTT Users, one of the most important performance criteria is the MCPTT Access time (KPI 1). The MCPTT Access time is defined as the time between when an MCPTT User request to speak (normally by pressing the MCPTT control on the MCPTT UE) and when this user gets a signal to start speaking. This time does not include confirmations from receiving users.
The MCPTT Access time (KPI 1) does not include the time for an MCPTT User to affiliate to the group. This is a common scenario within public safety, meaning that affiliations to MCPTT Groups are long lived during several working hours. KPI 1 is applicable in both an MCPTT Group call setup request and subsequent MCPTT Requests that are part of the same call. KPI 1 for subsequent MCPTT Requests might take a slightly shorter time than the first MCPTT setup request of the same call due to its potential need of resource allocation in terms of bearer establishment. However from an end user perspective there is no need to differentiate required performance for an MCPPT Group call setup request and subsequent MCPTT Requests.
The End-to-end MCPTT Access time (KPI 2) is defined as the time between when an MCPTT User requests to speak (normally by pressing the MCPTT control on the MCPTT UE) and when this user gets a signal to start speaking, including MCPTT call establishment (if applicable) and possibly acknowledgement from first receiving user before voice can be transmitted. Group calls can be set up with or without acknowledgements from receiving users.
For MCPTT Private Calls (with Floor control), end-to-end MCPTT Access time (also KPI 2) is measured from the initiating client’s Private call request to reception of either a Private Call response for automatic commencement or the MCPTT ringing indication for manual commencement. End-to-end access time for both automatic and manual commencement private calls (KPI 2) is shown in Figure 6.15.3.1-1.
NOTE: The End-to-end MCPTT Access time (KPI 2) is not applicable for an MCPTT Group transmission call setup when no acknowledgement is requested from any Affiliated MCPTT Group Member.
The Mouth-to-ear latency (KPI 3) is the time between an utterance by the transmitting user, and the playback of the utterance at the receiving user's speaker.
Figure 6.15.3.1-1 illustrates the MCPTT Access time and Mouth-to-ear latency.
6.15.3.2 Requirements
[R-6.15.3.2-001] KPI 1, KPI 2, and KPI 3 should be measured where there is negligible backhaul delay.
[R-6.15.3.2-002] The MCPTT Service shall provide the MCPTT Access time and Mouth-to-ear latency specified in this subclause to all MCPTT Users related to an MCPTT call regardless of call type (e.g., group, Private Call), group size and/or user density.NOTE: This ensures that all MCPTT Users experience the same performance regardless of whether the audio is transferred over unicast or multicast delivery.
[R-6.15.3.2-003] The MCPTT Service shall be capable of providing the performance specified herein for all Affiliated MCPTT Group Members in the Group Call when there is not a transcoder in the bearer path.
[R-6.15.3.2-004] The MCPTT Service shall be capable of providing the performance specified herein for all Participants in a Private Call when there is not a transcoder in the bearer path.
[R-6.15.3.2-005] The KPIs defined in this subclause shall apply in an 3GPP network under traffic load not exceeding 70% of each network nodes capacity.
[R-6.15.3.2-006] On networks with QoS services, the KPIs defined in this subclause shall apply when the total sector loading of the serving sector by MCPTT Users with equal or greater priority than the subject MCPTT User is less than 70%.
[R-6.15.3.2-007] The KPIs defined in this subclause shall apply to group calls when the transmitting MCPTT User is connected to the MCPTT Service and has selected an MCPTT Group.
[R-6.15.3.2-008] The KPIs defined in this subclause shall apply to group calls when the receiving MCPTT User is connected to the MCPTT Service and affiliated with the MCPTT Group.
[R-6.15.3.2-009] The KPIs defined in this subclause shall apply to Automatic Commencement Private Calls when both the transmitting and receiving MCPTT Users are connected to the MCPTT Service.
[R-6.15.3.2-010] Void
[R-6.15.3.2-011] When there are transcoding functions in the bearer path of the MCPTT Service, the performance provided by the MCPTT Service shall be no more than 40 ms greater than the performance specified herein when there are no transcoding functions in the bearer path.
[R-6.15.3.2-012] For group calls where no acknowledgement is requested from affiliated MCPTT group members, the MCPTT Service shall provide an MCPTT Access time (KPI 1) less than 300 ms for 95% of all MCPTT Request.
[R-6.15.3.2-012a] For group and private calls where the call is already established, the MCPTT Service shall provide an MCPTT Access time (KPI 1) less than 300 ms for 95% of all MCPTT PTT Requests.
[R-6.15.3.2-013] For MCPTT Emergency Group Calls and Imminent Peril Calls the MCPTT Service shall provide an MCPTT Access time (KPI 1) less than 300 ms for 99% of all MCPTT Requests.
[R-6.15.3.2-014] For group calls where automatic acknowledgement is requested from the UEs of the affiliated MCPTT group members, the MCPTT Service shall provide an End-to-end MCPTT Access time (KPI 2) less than 1000 ms for users under coverage of the same network.
[R-6.15.3.2-015] The MCPTT Service shall provide a Mouth-to-ear latency (KPI 3) that is less than 300 ms for 95% of all voice bursts.
[R-6.15.3.2-016] There shall be no (0 ms) initial lost audio at receiving user.
[R-6.15.3.2-017] There shall be no (0 ms) trailing lost audio at the end of the voice burst at receiving user.
[R-6.15.3.2-018] The KPIs defined in this subclause shall apply to Manual Commencement Private Calls when both the transmitting and receiving MCPTT Users are connected to the MCPTT Service.
[R-6.15.3.2-019] The MCPTT Service shall provide private call End-to-end MCPTT Access time (KPI 2) equal to or less than 1000 ms for users under coverage of the same network when the MCPTT private call is setup in the Manual Commencement mode.
[R-6.15.3.2-020] The MCPTT Service shall provide private call End-to-end MCPTT Access time (KPI 2) equal to or less than 1000 ms for users under coverage of the same network when the MCPTT private call is setup in the Automatic Commencement mode.
6.15.4 Late call entry performance
6.15.4.1 General overview
An MCPTT User is able to join or leave already ongoing MCPTT Group calls. Late call entry is the activity when an Affiliated MCPTT Group Member joins an MCPTT Group call in which other Affiliated MCPTT Group Members are already active. The Late call entry time (KPI 4) is the time to enter an ongoing MCPTT Group call measured from the time that a user decides to monitor such an MCPTT Group Call, to the time when the MCPTT UE's speaker starts to play the audio. The performance requirements for Late call entry time only applies to when there is ongoing voice transmitted at the time the MCPTT User joins the call.
In a Late call entry there might be an initial lost audio of the voice burst sent to the new Receiving MCPTT Group Member.
Figure 6.15.4.1-1 illustrates the Late call entry time.
6.15.4.2 Requirements
[R-6.15.4.2-001] The KPIs in this subclause shall apply for terrestrial use only, and when users are under coverage of the same network.
NOTE: Terrestrial use refers to using terrestrial 3GPP access, e.g. not using satellite 3GPP access. It includes support of air-to-ground scenarios, such as communication with MCPTT users in helicopters, fixed wing aircraft or other crewed aerial vehicles.
[R-6.15.4.2-002] The KPIs defined in this subclause shall apply in an 3GPP network under traffic load not exceeding 70% of each network nodes capacity.
[R-6.15.4.2-002a] The KPIs defined in this subclause shall apply to MCPTT users who have affiliated or have been affiliated by the network and are now performing late call entry due to activity on the affiliated group.
NOTE: Cases of UE mobility, or loss of coverage and re-establishment, are not covered.
[R-6.15.4.2-003] The maximum Late call entry time (KPI 4ᵃ) for calls without application layer encryption within one MCPTT system shall be less than 150 ms for 95% of all Late call entry requests.
[R-6.15.4.2-004] The maximum Late call entry time (KPI 4ᵇ) for application layer encrypted calls within one MCPTT system should meet the requirements for KPI 4 for unencrypted calls.
[R-6.15.4.2-005] The maximum Late call entry time (KPI 4ᵇ) for application layer encrypted calls within one MCPTT system shall be less than 350 ms for 95% of all Late Call Entries into encrypted calls.
[R-6.15.4.2-006] The Late call entry Time for encrypted calls interworking with other non-3GPP PTT systems should meet the requirements for KPI 4ᵇ for application layer encrypted calls within one MCPTT system.
NOTE: Additional delay deriving from the non-3GPP PTT system is not included in this KPI.
[R-6.15.4.2-007] The additional Late call entry Time for an MCPTT UE late entering an application layer encrypted call interworking with other non-3GPP PTT systems shall not exceed the difference in the encrypted and unencrypted Late call entry Times for the interworking system.
6.15.5 Audio / voice quality
[R-6.15.5-001] The MCPTT UE shall support at least one mandatory 3GPP voice codec.
NOTE 1: The UE implementation could include other non-3GPP voice codecs, e.g., TETRA voice codecs, P25 voice codecs [TIA-102.BABA: "Vocoder Description"].
NOTE 2: Refer to [R-6.4.9-006], which enables an MCPTT Administrator to set the preferred voice codec for an MCPTT Group.
[R-6.15.5-002] When an MCPTT call is within one MCPTT system the average MOS-LQO [Mean Opinion Score – Listening Quality Objective] shall be greater than or equal to 3.0 measured according to the ITU standard Perceptual Evaluation of Speech Quality (PESQ) as defined in P.862 [ITU-T Recommendation P.862: "Perceptual evaluation of speech quality (PESQ): An objective method for end-to-end speech quality assessment of narrow-band telephone networks and speech codecs"] and P.862.1 [ITU-T Recommendation P.862.1: "Mapping function for transforming P.862 raw result scores to MOS-LQO"].
[R-6.15.5-003] When an MCPTT call involves interworking with other non-3GPP PTT systems the average MOS-LQO shall be greater than or equal to 2.7 measured according to the ITU standard PESQ as defined in P.862 [ITU-T Recommendation P.862: "Perceptual evaluation of speech quality (PESQ): An objective method for end-to-end speech quality assessment of narrow-band telephone networks and speech codecs"] and P.862.1 [ITU-T Recommendation P.862.1: "Mapping function for transforming P.862 raw result scores to MOS-LQO"].
[R-6.15.5-004] When an MCPTT call is within one MCPTT system the average MOS-LQO shall be greater than or equal to 3.0 measured according to the ITU standard Perceptual Objective Listening Quality Assessment (POLQA) as defined in P.863 [ITU-T Recommendation P.863: "Perceptual objective listening quality assessment"].
[R-6.15.5-005] When an MCPTT call involves interworking with other non-3GPP PTT systems the average MOS LQO shall be greater than or equal to 2.7 measured according to the ITU standard POLQA as defined in P.863 [ITU-T Recommendation P.863: "Perceptual objective listening quality assessment"].
6.15.6 Radio Resource Efficiency Performance
[R-6.15.6-001] Void
MCVideo Performance and Quality Requirements
3GPP TS 22.281 "Mission-Critical Video services" (V17.0.0 (2022-03)) (22281-h00) clause 5.4 "MCVideo specific requirements - Performance and quality requirements for on-network and off-network"
5.4 Performance and quality requirements for on-network and off-network
5.4.1 MCVideo device and camera moving at high speed
5.4.1.1 Service description
Motion affects the length of time a desired target is shown in the video frame, and can cause the target to blur. The level of motion in a particular piece of video content can have a huge impact on the performance of a video coder. A moving camera might also produce video that is much more difficult to encode efficiently.
For public safety applications, if the video is considered “mission critical,” the loss or interruption of a video stream or any significant delay in the delivery of the video stream might be unacceptable for processing by the video decoder. Therefore, if a source of video content is in motion and handovers between radio coverage areas are necessary, then it is important that the handovers are handled in a manner to minimize loss, interruption and delay of the video stream.
5.4.1.2 Requirements
[R-5.4.1.2-001] The MCVideo Service shall support one-to-one video communications between authorized MCVideo UEs when the transmitting and/or receiving MCVideo UEs are moving at different speeds, from 0 km/h to 160km/h.
[R-5.4.1.2-002] The MCVideo Service shall support group video communications between authorized MCVideo UEs when the transmitting and/or receiving MCVideo UEs are moving at different speeds, from 0 km/h to 160km/h.
NOTE: It is assumed that communications in high speed trains might be possible with special design.
5.4.2 Latencies
[R-5.4.2-001] The MCVideo Service shall ensure that transmission of urgent real time video transmissions shall be started within 2 seconds after the request.
[R-5.4.2-002] The MCVideo Service shall ensure that the end-to-end delay from transmitting MCVideo UE to receiving MCVideo UE or console for urgent real time video transmissions shall be no more than 1 s.
[R-5.4.2-003] A sending MCVideo UE may be configured to begin storing video immediately from the time the user requests an MCVideo transmission. In this case the end to end delay shall not exceed 1 s plus the commencement delay (up to 2 s).
[R-5.4.2-004] The MCVideo Service shall ensure that the end-to-end delay from transmitted MCVideo UE to receiving MCVideo UE or console for non-urgent real time priority video transmissions shall be no more than 10 s.
[R-5.4.2-005] Synchronisation between video and audio when played at the MCVideo receiving UE or console shall be within 50 ms.
MCX Services Security
3GPP TS 22.280 "Mission Critical Services Common Requirements (MCCoRe); Stage 1" (V18.2.0 (2022-06)) (22280-i20) clause 5.12 "MCX Service requirements common for on the network and off the network - Security"
5.12 Security
[R-5.12-001] The MCX Service shall provide a means to support the confidentiality and integrity of all user traffic and signaling at the application layer.
[R-5.12-002] The MCX Service shall support MCX User with globally unique identities, independent of the mobile subscriber identity (IMSI) assigned by a 3GPP network operator to UEs.
[R-5.12-003] The MCX Service identities shall be part of the MCX Service application service domain.
[R-5.12-004] The MCX Service identities shall form the basis of the MCX Service application layer security for the MCX Service.
[R-5.12-005] The MCX Service shall provide the MCX User with a mechanism to perform a single authentication for access to all authorized features.
[R-5.12-006] The MCX Service shall provide a means for an authorized MCX UE to access selected MCX Service features prior to MCX User authentication.
[R-5.12-007] The MCX Service shall require authentication of the MCX User before service access to all authorized MCX Service features is granted.
NOTE: The MCX Service features available are based on the authenticated user identity(s).
[R-5.12-008] Subject to regulatory constraints, the MCX Service shall provide a means to support confidentiality, message integrity, and source authentication for some information exchanges (e.g., MCX Service User Profile management, kill commands) that have the potential to disrupt the operation of the target MCX UE.
[R-5.12-009] The MCX Service shall provide a means to support end-to-end security for all media traffic transmitted between MCX UEs.
[R-5.12-010] End-to-end security shall be supported both within and without network coverage and regardless of whether the traffic is transmitted directly or via the network infrastructure.
[R-5.12-011] Subject to regulatory constraints, the MCX Service shall provide a cryptographic key management service(s).
[R-5.12-012] The cryptographic key management service(s) shall support both pre-provisioning and over-the-air provisioning of cryptographic keys.
[R-5.12-013] The cryptographic key management service(s) shall ensure that cryptographic keys are confidentiality protected, integrity protected and authenticated when delivered over-the-air.
[R-5.12-014] The MCX Service shall provide end-to-end confidentiality and integrity protection to the MCX User Profile when transferred to and/or from and while stored on an MCX Server, an MCX UE or both.
3GPP TS 22.280 "Mission Critical Services Common Requirements (MCCoRe); Stage 1" (V18.2.0 (2022-06)) (22280-i20) clause 6.13 "MCX Service requirements specific to on-network use - Security"
6.13 Security
6.13.1 Overview
Security covers areas designed to protect the confidentiality, integrity, and availability of information that is processed, stored, and transmitted. The security requirements listed here cover the areas of cryptographic protocols, authentication, access control, regulatory issues and storage control.
6.13.2 Cryptographic protocols
[R-6.13.2-001] The MCX Service shall employ open cryptographic standards, subject to applicable local policy (e.g., Federal Information Processing Standards (FIPS) 140-2).
[R-6.13.2-002] The MCX Service shall allow for update to new cryptographic operations and methods without making obsolete existing operations and methods, or requiring upgrade of all user equipment simultaneously.
[R-6.13.2-003] The MCX Service shall allow for the coexistence of a multiplicity of cryptographic suites.
NOTE 1: A "cryptographic suite" is a consistent collection of cryptographic operations (e.g., encryption and message authentication) spanning the totality of required cryptographic operations for MCX Service. That is, if MCX Service requires a stream cipher, a message authentication code, and a secure hash, then counter-mode AES-256, CMAC with AES-256 as an underlying cipher, and SHA-512 would constitute a cryptographic suite for MCX Service.
NOTE 2: The definition and identification of cryptographic suites and algorithms need not all be within the scope of 3GPP.
6.13.3 Authentication
[R-6.13.3-001] The MCX Service shall provide a means by which an MCX UE can require authentication of the MCX Service.
6.13.4 Access control
[R-6.13.4-001] The MCX Service shall support suspending or disabling of access from an MCX UE or an MCX User to the MCX Service.
[R-6.13.4-002] An MCX User who has a profile that has been deleted or suspended shall be prevented from using that MCX Service User Profile to access the MCX Service.
[R-6.13.4-003] The MCX Service shall provide a mechanism to temporarily disable an MCX UE remotely by the MCX Service Administrator or an authorized MCX User.
[R-6.13.4-004] The MCX Service shall only allow a user to affiliate to or select an enabled MCX Service Group (i.e., not disabled).
[R-6.13.4-005] A temporarily disabled MCX UE, which has limited access capability per Mission Critical Organization policy, shall be able to be re-enabled by the MCX Service Administrator or an authorized MCX User.
[R-6.13.4-006] The MCX Service shall provide a mechanism to re-enable a temporarily disabled MCX UE by the MCX Service Administrator or an authorized MCX User.
[R-6.13.4-007] The MCX Service shall provide a mechanism to permanently disable an MCX UE by the MCX Service Administrator or an authorized MCX User.
[R-6.13.4-008] The permanently disabled MCX UE shall remove all MCX Service User Profiles stored in the MCX UE.
[R-6.13.4-009] The permanently disabled MCX UE shall have no access to MCX Services.
[R-6.13.4-010] The security solution for the MCX Service shall minimize the impact of a compromised MCX UE on other MCX UEs.
6.13.5 Regulatory issues
[R-6.13.5-001] The MCX Service shall support lawful interception.
6.13.6 Storage control
[R-6.13.6-001] The MCX Service shall provide all relevant security for media storage (e.g., video or data) on the MCX UE (e.g., data encryption, access only to authorized MCX Group Members).
MCX Services Dynamic Regrouping
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 4.2 "Mission Critical Push To Talk overview - Typical use of the MCPTT Service"
4.2 Typical use of the MCPTT Service
NOTE: Even though this subclause is written from an organization specific perspective the text is illustrative for typical use of MCPTT Services by all MCPTT Users.
Public safety workers often operate in groups and perform different tasks during the day/week. Many tasks and operations are controlled, assisted and/or coordinated by a dispatcher.
For their communications public safety workers are organized in groups. People that are working together communicate in the same MCPTT Group, the group communication helping them to coordinate quickly.
People with different tasks often communicate in separate MCPTT Groups.
Many of the public safety tasks are routine tasks, that are handled by standard procedures and communication structures, using dedicated MCPTT Groups.
Communication structures and MCPTT Groups are also prepared for the handling of large incidents and control of large events. Similarly there are MCPTT Groups and procedures for coordination with public safety workers from other organizations and/or other countries.
The standard procedures and communication structures help the public safety workers to do their work successfully. This results in a long list of (>100) MCPTT Groups available to a public safety worker, from which the correct one is selected depending on the task. To help the public safety worker to quickly find and select the correct MCPTT Group for the task, the MCPTT Groups in the radio are often structured in folders and/or accessible via key-shortcuts.
In addition to pre-established MCPTT Groups that users select, there are also provisions in MCPTT systems to merge MCPTT Groups and to select on behalf of a user which group they should be using and for a dispatcher to push them onto it.
[...]
3GPP TS 22.280 "Mission Critical Services Common Requirements (MCCoRe); Stage 1" (V18.2.0 (2022-06)) (22280-i20) clause 6.6 "MCX Service requirements specific to on-network use - Dynamic group management (i.e., dynamic regrouping))"
6.6 Dynamic group management (i.e., dynamic regrouping)
6.6.1 General dynamic regroupingγ
[R-6.6.1-001] Group Regroup and User Regroup operations shall be manageable by authorized MCX Users.
[R-6.6.1-002] The temporary group formed by Group Regroup or User Regroup operations shall persist until torn down by an authorized MCX User.
[R-6.6.1-003] The priority of the temporary group formed by a Group Regroup or User Regroup operations shall be established by the creator of the group within bounds established by MCX Service Administrators.
[R-6.6.1-004] The MCX Service shall enable an MCX Service Administrator to grant and to revoke the authorization of an MCX User to be able to perform dynamic regrouping operations.
[R-6.6.1-005] The MCX Service shall enable an MCX Service Administrator to configure whether a temporary group is encrypted.
[R-6.6.1-006] The temporary group formed by Group Regroup or User Regroup operations shall be treated like any other MCX Service Group, except the ability for a temporary group formed by a Group Regroup operation to be included in another Group Regroup operation.
6.6.2 Group regrouping
6.6.2.1 Service description
Group regrouping enables dispatchers or any authorized user to temporarily combine MCX Service Groups. A dispatcher uses group regrouping for different reasons.
Due to an incident in an area it can be necessary to temporarily enable MCX Users from different MCX Service Groups to communicate to each other to coordinate. After the incident the dispatcher cancels the group regrouping and the MCX Users continue with their original configured MCX Service Groups.
During quiet periods control room managers can decide to combine MCX Service Groups and handle their operations and communications with one dispatcher. In the busier period the group regrouping is cancelled and the MCX Service Groups are handled by separate dispatchers.
MCX Service Groups that are being combined in a Group Regroup operation may belong to the same or different MCX servers and may have different security and priority levels, different floor control methods, as well as different operational characteristics (e.g. different call start criteria, different call or session hang timers, different transmit time limits, different override settings, different floor control parameters such as queue depth, queing policy and time-to-live in the queue). However, the newly created temporary MCX Service Group can have only a single security level, priority level, floor control method, and set of operational characteristics. The MCX Service will apply the proper setting of those parameters for the new MCX Service Group.
6.6.2.2 Requirements
[R-6.6.2.2-001] The MCX Service shall provide a means of dynamically combining a multiplicity of groups into a new, temporary group (i.e., to perform a "Group Regroup operation").
[R-6.6.2.2-002] The MCX Service shall notify MCX Users when and how any of their affiliated groups are affected by a Group Regroup operation including notification of modified security, priority, floor control, and other operational characteristics.
[R-6.6.2.2-003] The MCX Service shall provide notification and information to an authorized MCX User if that user is attempting to Group Regroup MCX Service Groups of different security levels, priority levels, and/or floor control methods.
[R-6.6.2.2-004] The MCX Service shall enable an authorized MCX User to set the security level of the Group created from a Group Regroup operation. Where an MCX User does not specify the security level the MCX Service shall default the security level to be set to the lowest security level of the constituent Groups.
[R-6.6.2.2-005] The MCX Service shall notify Affiliated MCX Service Group Members of a constituent MCX Service Group when the security level of the MCX Service Group that they are using lowers as a result of a Group Regroup operation.
[R-6.6.2.2-006] The MCX Service shall enable an authorized MCX User to set the priority level of the group formed from a Group Regroup operation. Where an MCX User does not specify the priority level the MCX Service shall default the priority level to be set to the highest priority level of the constituent Groups.
[R-6.6.2.2-007] Broadcast Groups shall be able to be included in a Group Regroup operation.
[R-6.6.2.2-008] The MCX Service shall enable an authorized MCX User or MCX Service Administrator to configure default settings and rules for the operational characteristics of temporary MCX Service Groups resulting from Group Regroup operations (e.g. call start criteria, hang time).
[R-6.6.2.2-009] The MCX Service shall enable an authorized MCX User to specify the operational characteristics of temporary MCX Service Groups resulting from Group Regroup operations either explicitly, or via pre-defined implicit rules, or via pre-configured default values, or, in case all the constituent Groups have in common the same operational characteristics, to use the common settings.
[R-6.6.2.2-010] The MCX Service shall enable an authorized MCX User to set the floor control method of the Group created from a Group Regroup operation when the Group Regroup includes one or more groups configured for audio cut-in operation. Where an MCX User does not specify the floor control method the MCX Service shall default to using normal floor control for the Group Regroup (i.e. do not use audio cut-in).
[R-6.6.2.2-011] The MCX Service shall prevent an authorized MCX User from including a temporary group in a Group Regroup operation.
[R-6.6.2.2-012] The MCX Service shall prevent an authorized MCX User from including a MCX Group that is already part of an existing Group Regroup in a different Group Regroup operation.
[R-6.6.2.2-013] The MCX Service shall be configurable either to prevent or to allow all authorized MCX Users from including a MCX Group that is in emergency state in a Group Regroup operation.
6.6.3 Τemporary Broadcast Groups
[R-6.6.3-001] The MCX Service shall enable an authorized MCX User to create a temporary Group-Broadcast Group from a multiplicity of MCX Service Groups within that MCX Service.
[R-6.6.3-001a] The MCX Service shall enable an authorized MCX User to create a temporary User-Broadcast Group from a multiplicity of MCX Users within that MCX Service.
[R-6.6.3-001b] The MCX Service shall enable an authorized MCX User to create a temporary Broadcast Group from a combination of a multiplicity of MCX Service Groups and a multiplicity of MCX Users within that MCX Service.
[R-6.6.3-002] The MCX Service shall only allow the creator of the temporary Broadcast Group to transmit on it.
6.6.4 User regrouping
6.6.4.1 Service description
6.6.4.1.1 User regrouping controlled by dispatcher or authorized user
There is a need for a mechanism for combining MCX Users into a new MCX Service Group under control by a dispatcher or authorized user to support ad-hoc communication needs.
In the operational MCX Service environment, most tasks are covered by standard procedures and communication structures, and MCX Users can easily access the MCX Service Groups to handle their tasks.
Exceptionally it could happen that there is an urgent need for a dedicated set of individual MCX Users to communicate in an MCX Service Group, but that this is not foreseen in the communication structure. This could be due to extreme conditions or due to a cooperation that is outside normal procedures.
User Regrouping enables dispatchers or authorized users to instantaneously provide a dedicated MCX Service Group to these MCX Users to enable the required communication. Depending on configuration the MCX Users could be automatically affiliated to this MCX Service Group. After the operation this MCX Service Group is removed by the dispatcher or authorized user.
6.6.4.1.2 Automatic user regrouping
There is also a need to for an automatic mechanism that determines a set of individual MCX Users to become members of a MCX Service Group and to automatically become affiliated to that MCX Service Group.
These individual MCX Users are selected automatically by the MCX Service based on certain parameters (e.g. location, geographic area, participant type, direction of movement, speed). If MCX Service Group members do not meet the parameters anymore they will automatically be de-affiliated from the MCX Service Group and removed from the MCX Service Group member list. The remaining MCX Service Group members and the MCX Service Group member(s) removed will be informed accordingly. Conversely, MCX Users that are starting to meet the parameters (e.g., due to location changes) will automatically be added and affiliated to the MCX Service Group. The MCX Service Group members and the added MCX Service Group member(s) will be informed accordingly.
6.6.4.2 Requirements
[R-6.6.4.2-001] The MCX Service shall provide a means for combining a multiplicity of MCX Users into a new, temporary group (i.e., to perform a "User Regroup operation").
[R-6.6.4.2-002] The MCX Service shall provide a means for combining a multiplicity of MCX Users into a new, temporary group based on a parameter or a combination of parameters (e.g., particular geographic area, Participant type, initiation of urgent type communication such as MCX Emergency Alert or MCX Emergency Group Communication).
[R-6.6.4.2-002a] The MCX Service shall provide a means for automatically combining a multiplicity of MCX Users into a temporary MCX Service Group based on certain criteria. For example, the criteria may include one or more parameters from the list below:
- A specific element or combination of specific elements in the functional alias of a MCX User
- Location (including speed and heading) of a MCX User
- Location or particular geographic area specified by an MCX Service Administrator
- MCX Service configuration (e.g. MCX User responsible for a certain geographic area or MCX User responsible for a certain MCX Service Group)
[R-6.6.4.2-002b] The MCX Service shall be able to automatically update the memberslist of a temporary MCX Service Group based on certain criteria i.e. to remove MCX Users no more meeting the criteria and add MCX Users starting to meet the criteria. For example, the criteria may include one or more parameters from the list below:
- A specific element or combination of specific elements in the functional alias of a MCX User
- Location (including speed and heading) of a MCX User
- Location or particular geographic area specified by an MCX Service Administrator
- MCX Service configuration (e.g. MCX User responsible for a certain geographic area or MCX User responsible for a certain MCX Service Group)
[R-6.6.4.2-003] The MCX Service shall provide a mechanism to preconfigure the parameters for a particular User Regroup operation, such that an authorized MCX User activates this preconfigured User Regroup and communicates with this temporary group with minimal delay.
NOTE: An example of the use of this functionality is for an MCX User to communicate with particular other MCX Users within a predefined radius of the MCX User's Location. This functionality is likely to be for urgent type communications such as MCX Service Emergency Group Communications.
[R-6.6.4.2-004] The MCX Service shall notify MCX Users when they are affected by a User Regroup operation.
[R-6.6.4.2-005] The MCX Service shall provide a mechanism for an MCX Service Administrator to configure whether an MCX Service system shall automatically affiliate the MCX Users included in the temporary group created by the User Regroup operation.
6.6.5 Dynamic Group Participation
6.6.5.1 Service description
Dynamic group participation enables control of group affiliation, de-affiliation, and selection on MCX Service Groups based on various combinations of criteria. For highly mobile MCX UEs, such as those used in railway communication, the group affiliation and selection needs to change, for example, when a train crosses a controlling area border.
6.6.5.2 Requirements
[R-6.6.5.2-001] The MCX Service shall enable an MCX User to automatically affiliate to one or more MCX Service Groups based on one, or a combination of, criteria.
[R-6.6.5.2-002] The MCX Service shall be able to automatically affiliate an MCX User to one or more MCX Service Groups based one, or a combination of, criteria.
[R-6.6.5.2-003] The MCX Service shall enable an MCX User to automatically choose the Selected MCX Service Group based on one, or a combination of, criteria.
[R-6.6.5.2-004] The MCX Service shall be able to automatically choose the Selected MCX Service Group of an MCX User based on one, or a combination of, criteria.
[R-6.6.5.2-005] The MCX Service shall enable an MCX User to automatically de-affiliate from one or more currently affiliated groups based on a change to one, or a combination of, criteria.
[R-6.6.5.2-006] The MCX Service shall be able to automatically de-affiliate an MCX User from one or more currently affiliated groups based on a change to one, or a combination of, criteria.
[R-6.6.5.2-007] The MCX Service shall be able to prevent an MCX User de-affiliating from specific currently affiliated groups based on one, or a combination of, criteria.
NOTE: Examples of criteria for the above requirements could include one or more parameters from the list below:
- A specific element or combination of specific elements in the functional alias of a MCX User
- Location (including speed and heading) of a MCX User
- Location or particular geographic area specified by an MCX Service Administrator
- MCX Service configuration (e.g. MCX User responsible for a certain geographic area or MCX User responsible for a certain MCX Service Group)
[R-6.6.5.2-008] The MCX Service shall enable an MCX User to select on specific MCX UEs whether automatic affiliation and/or de-affiliation is allowed.
3GPP TS 22.280 "Mission Critical Services Common Requirements (MCCoRe); Stage 1" (V18.2.0 (2022-06)) (22280-i20) clause 6.15.5 "MCX Service requirements specific to on-network use - Additional services for MCX Service communications - MCX Service Ad hoc Group Communication"
6.15.5 MCX Service Ad hoc Group Communication
6.15.5.1 Overview
Due to an incident in an area, or a special operation, it can be necessary to coordinate MCX Users using Group Communication where these users do not normally work together and do not share any groups in common. MCX Service Ad hoc Group Communication enables authorized users to combine a random set of MCX Users into a group communication. The main characteristics of this ad hoc group communication are:
a) The ad hoc group does not exist until it is spontaneously created during the communication.
b) The ad hoc group ceases to exist when the communication terminates.
c) The ad hoc group does not support ‘persistent state’ communication, e.g. emergency state.
A single communication consists of one or more media transmissions until explicitly terminated by various means. MCX Users that are being combined in an ad hoc group communication may be served by the same or different MCX systems and may normally use MCX Service Groups with different security and priority levels, different floor control methods, and other different operational characteristics. The MCX Service Ad hoc Group Communication will use a common security level, priority level, floor control method, and set of operational characteristics for the participants during a communication. As with any group communication, the priority level can change dynamically.
The ad hoc group is used for a single communication or for an emergency alert and it does not persist when the communication is terminated or when the emergency alert is cancelled. Authorized users can recreate the ad hoc group for subsequent communications, or request creation of a permanent MCX Service Group from the participants in the ad hoc group communication.
NOTE: When the MCX Service Ad hoc Communication is terminated the list of participants may be retained for ease of initiating another ad hoc communication with the same participants.
6.15.5.2 General aspects
[R-6.15.5.2-001] The MCX Service shall provide a mechanism for an authorized MCX User to combine an ad hoc multiplicity of MCX Users into a MCX Service Ad hoc Group Communication. NOTE: Selection of the list of MCX Users can be manual, or automatic based on certain criteria (e.g., location). This is left for implementation.
[R-6.15.5.2-002] An MCX Service Ad hoc Group Communication is a type of MCX Service Group communication and shall support MCX Service Group Communication mechanisms for call processing (e.g., transmit request queuing, hang time, broadcast mode).
[R-6.15.5.2-003] MCX Service Ad hoc Group Communications shall be terminated using the same mechanisms as MCX Service Group communications (e.g., initiator release, server release, hang time expiration).
[R-6.15.5.2-004] The MCX Service shall provide a mechanism for an MCX Service Administrator to configure additional conditions under which MCX Service Ad hoc Group Communication shall be terminated (e.g., last Participant leaving, second last Participant leaving, initiator leaving).
[R-6.15.5.2-005] When an MCX Service Ad hoc Group Communication is terminated the group shall not persist.
[R-6.15.5.2-005a] When an MCX Service Emergency Alert based on ad hoc group is cancelled, the group shall not persist.
[R-6.15.5.2-006] The MCX Service shall provide a mechanism for the initiator of a MCX Service Ad hoc Group Communication to indicate which MCX Users have to mandatorily acknowledge the setup request before the media transmission proceeds.
[R-6.15.5.2-007] The MCX Service shall provide a mechanism for an authorized initiator of a MCX Service Ad hoc Group Communication to define the communication parameters for the Ad hoc Group Communication (e.g. priority, hang time, broadcast/non-broadcast)
[R-6.15.5.2-008] MCX Service Ad hoc Group Communications shall be able to support the same urgency as MCX Service Group communication (e.g., general group, emergency, imminent peril).
[R-6.15.5.2-009] MCX Service Ad hoc Group Communications shall support the applicable security requirements as identified in sub-clause 5.12.
[R-6.15.5.2-010] The MCX Service shall provide a mechanism for the initiator of an MCX Service Ad hoc Group Communication to request that the list of participants is suppressed.
[R-6.15.5.2-011] The MCX Service shall provide a mechanism for authorized MCX Users to create a permanent MCX Service Group from the members of the MCX Service Ad hoc Group communication.
[R-6.15.5.2-012] The MCX Service shall provide a mechanism for the initiator to add or remove participants during an in progress MCX Service Ad hoc Group communication.
[R-6.15.5.2-013] The MCX Service shall provide a mechanism for a participant to join an in progress MCX Service Ad hoc Group communication.
[R-6.15.5.2-014] The MCX Service shall provide a mechanism for the initiator of an MCX Service Ad hoc Group Communication to request that the list of participants be determined and updated by the MCX Service system using pre-defined criteria.
6.15.5.3 Administrative
[R-6.15.5.3-001] The MCX Service shall provide a mechanism for an MCX Service Administrator to configure which MCX Users, within their authority, are authorized to initiate a MCX Service Ad hoc Group Communication.
[R-6.15.5.3-002] The MCX Service shall provide a mechanism for an MCX Service Administrator to configure the maximum number of MCX Users who can participate in a MCX Service Ad hoc Group Communication.
[R-6.15.5.3-003] The MCX Service shall provide a mechanism for an MCX Service Administrator to configure which MCX Users are authorized to participate in a MCX Service Ad hoc Group Communication. [TS 22.280 R-6.7.2-003: The MCX Service should provide a mechanism for authorized MCX Users to query whether a particular MCX User is capable of participating in a Private Communication.]
[R-6.15.5.3-004] The MCX Service shall provide a mechanism for an MCX Service Administrator to define the default parameters for MCX Service Ad hoc Group communication (e.g., priority, hang time, broadcast mode).
[R-6.15.5.3-005] The MCX Service shall provide a mechanism for an MCX Service Administrator to configure whether MCX Service Ad hoc Group Communication is allowed on the MCX system regardless of individual MCX User authorizations.
6.15.5.4 Notification and acknowledgement for MCX Service Ad hoc Group Communications
[R-6.15.5.4-001] The MCX Service shall provide mechanisms for notification and acknowledgement of MCX Service Ad hoc Group Communications as defined in section 6.2.1 [MCX Service requirements specific to on-network use - MCX Service communications - Notification and acknowledgement for MCX Service Group Communications].
NOTE: For MCX Service Ad hoc Group Communications a participant is considered an affiliated member of the group during communication setup.
MCX Services Control and Management by Mission-Critical Organizations
3GPP TS 22.280 "Mission Critical Services Common Requirements (MCCoRe); Stage 1" (V18.2.0 (2022-06)) (22280-i20) clause 5.16 "MCX Service requirements common for on the network and off the network - Control and Management by Mission-Critical Organizations"
5.16 Control and Management by Mission-Critical Organizations
5.16.1 Overview
Clause 5.16 contains general requirements for the management of the MCX Service by Mission-Critical Organizations sharing the same MCX Service system, and more specific requirements pertaining to management controls and operational visibility, and to the management of security services.
5.16.2 General requirements
[R-5.16.2-001] The MCX Service shall be able to support multiple Mission-Critical Organizations, each with their own MCX Users and MCX Service Groups, on the same MCX Service system.
[R-5.16.2-002] The MCX Service shall provide a mechanism by which Mission-Critical Organizations designate and manage (i.e., add, delete, change authorizations, etc.) MCX Service Administrators with authority to manage users, groups, other MCX Service Administrators, security controls, and other mission-affecting parameters (e.g., authorizations and priorities) of the MCX Service.
[R-5.16.2-003] The MCX Service shall protect the operational privacy of Mission-Critical Organizations by providing effective separation between the administrative and security management (e.g., key) parameters of those organizations except as authorized by the Mission-Critical Organizations involved.
[R-5.16.2-004] The MCX Service shall protect the administrative and security management parameters of Mission-Critical Organizations from viewing and manipulation by individuals (including those within and outside of the mission-critical organization) not explicitly authorized by the Mission-Critical Organization.
[R-5.16.2-005] The MCX Service shall provide a mechanism by which Mission-Critical Organizations may share subsets of their administrative and security parameters with other Mission-Critical Organizations.
NOTE: The purposes of these requirements protect the operational security of organizations while still allowing for the interworking of MCX UE and Users under the control of Mission-Critical Organizations.
5.16.3 Operational visibility for Mission-Critical Organizations
[R-5.16.3-001] The MCX Service shall provide a means by which an MCX Service Administrator associated with a Mission Critical Organization has visibility into the operational status of the service (e.g., during a natural disaster).
5.16.4 Sharing of administrative configuration between Mission-Critical Organizations
Mission-Critical Organizations can deploy their own 3GPP standardized mobile, local, countrywide, or national broadband mission-critical communications systems. In order to grant visiting MCX Service Users access to a Partner MCX Service System and its services, a mechanism is required, which allows the exchange of administrative configuration between connected MCX Service Systems.
NOTE: Administrative configuration is used for adding MCX Service Users into a Partner MCX Service System’s user and group databases, modifying security controls and other mission-affecting parameters, and for enabling or disabling certain services for specific users. Relevant information can be exchanged, for example, prior to the visiting MCX Service Users arriving at a Partner MCX Service System or dynamically during events.
[R-5.16.4-001] An MCX Service shall provide a mechanism to allow an authorized MCX User to request MCX User configuration changes in one or more Partner MCX Service Systems (e.g., priorities, authorizations).
[R-5.16.4-002] An MCX Service shall provide a mechanism to allow an authorized MCX User to evaluate and respond to requests for configuration changes from Partner MCX Service Systems.
[R-5.16.4-003] An MCX Service shall provide a mechanism to allow an authorized MCX User to configure automatic responses to categories of requests for configuration changes from Partner MCX Service Systems (e.g., particular users, or groups).
[R-5.16.4-004] An MCX Service shall provide a mechanism to allow an authorized MCX User to request configuration information (e.g., users, groups, security level) from Partner MCX Service Systems.
[R-5.16.4-005] An MCX Service shall provide a mechanism to allow an authorized MCX User to send configuration information to Partner MCX Service Systems.
[R-5.16.4-006] An MCX Service shall provide a mechanism to allow an authorized MCX User to exchange operationally relevant information for specific MCX Users, e.g., MCX User capability information, with Partner MCX Service Systems. NOTE: Capability information could include, but is not limited to, information such as chemical, biohazard, medical, or equipment handling capabilities for a specific MCX User.
[R-5.16.4-007] An MCX Service System shall provide a mechanism to allow the secure exchange of administrative and security-related information with interconnected MCX Service systems without compromising the integrity and security of either system.
[R-5.16.4-008] An MCX Service System shall provide a mechanism to allow the exchange of administrative and security-related information with interconnected MCX Service systems without exposing the internal network topology of either system.
Blue Force Net
3GPP-compliant
Mission-Critical
Mobile Communications
MCX Services Select Details
MCX Services Prioritization
3GPP TS 22.280 "Mission Critical Services Common Requirements (MCCoRe); Stage 1" (V18.2.0 (2022-06)) (22280-i20) clause 5.1.7 "MCX Service requirements common for on the network and off the network - MCX Service General Group Communications requirements - Prioritization"
5.1.7 Prioritization
[R-5.1.7-001] The MCX Service shall provide a mechanism to organize MCX Service Groups into a hierarchy(ies).
[R-5.1.7-002] The MCX Service shall provide a mechanism to prioritize MCX Service Group Communications based on the priorities associated with elements of the communication (e.g., service type, requesting identity, and target identity).
3GPP TS 22.280 "Mission Critical Services Common Requirements (MCCoRe); Stage 1" (V18.2.0 (2022-06)) (22280-i20) clause 6.4.7 "MCX Service requirements specific to on-network use - General MCX Service Group Communications - Prioritization"
6.4.7 Prioritization
[R-6.4.7-001] The MCX Service shall provide a mechanism to establish, dynamically and in real-time, the relative priorities of different MCX Service Group Communications with respect to transport.
[R-6.4.7-002] The MCX Service shall provide a mechanism to establish, dynamically and in real-time, the relative priorities of different MCX Service Group Communications with respect to presentation.
[R-6.4.7-003] The MCX Service shall provide a mechanism to establish, dynamically and in real-time, the relative priorities of MCX Service Groups Communications and other traffic with respect to transport.
[R-6.4.7-004] The MCX Service shall provide a mechanism to establish, dynamically and in real-time, the relative priorities of MCX Service Groups Communications and other traffic with respect to
3GPP TS 22.280 "Mission Critical Services Common Requirements (MCCoRe); Stage 1" (V18.2.0 (2022-06)) (22280-i20) clause 6.8.1 "MCX Service requirements specific to on-network use - MCX Service priority requirements - General"
6.8.1 General
[R-6.8.1-001] The MCX Service shall support multiple MCX Service Application priorities, which are mapped to priority levels, based on network operator policy.
[R-6.8.1-002] MCX Service shall support multiple pre-emptive priorities.
[R-6.8.1-003] The MCX Service shall provide a mechanism for MCX Service Administrators to create, a pre-emption hierarchy for MCX Service Group transmissions and their associated users (i.e., to facilitate local management of the service and its resources).
[R-6.8.1-004] The MCX Service shall support MCX Service Groups with the permission to pre-empt other MCX Service communications.
[R-6.8.1-005] In case of resource shortage a communication made to a group with pre-emption permissions shall be given resources to complete this communication by pre-empting lower priority communications.
NOTE: An MCX Service communication that needs the use of pre-emption still needs to satisfy the communication setup requirements.
[R-6.8.1-006] MCX Service shall support queuing and retention by priority.
[R-6.8.1-007] The MCX Service shall provide a mechanism for an MCX Service Administrator to establish the priority hierarchy and characteristics of MCX Service Group transmissions.
[R-6.8.1-008] The MCX Service shall enable an MCX Service Administrator to prioritize MCX Service Groups in relation to other MCX Service Groups (with respect to transport and presentation).
[R-6.8.1-009] The MCX Service shall enable an MCX Service Administrator to set the priority for a subset of a Mission Critical Organization's MCX Service Groups relative to other subsets of a Mission Critical Organization's MCX Service Groups subordinate to the MCX Service Administrator's authority.
[R-6.8.1-010] When determining priority for an MCX Service communication, the MCX Service shall use the MCX User/Participant's attributes (e.g., first/second responder, supervisor, dispatcher, on/off duty) and the MCX Service Group's attributes (e.g., type of group, owning organization of the group, MCX Service Emergency, Imminent Peril).
[R-6.8.1-011] When determining priority for an MCX Service transmission, the MCX Service shall use the MCX User/Participant's attributes (e.g., first/second responder, supervisor, dispatcher, on/off duty) and the MCX Service Group's attributes (e.g., type of group, owning agency of the group, MCX Service Emergency, Imminent Peril).
[R-6.8.1-012] The MCX Service shall provide a means for the attributes used for determining the priority for MCX Users and Groups to influence the Priority and QoS for all MCX UEs associated with the MCX User.
[R-6.8.1-013] Based on the attributes used for determining the priority for MCX Users and Groups, the MCX Service shall provide consistent and deterministic priority for all MCX Users within their Primary MCX Service System.
[R-6.8.1-014] Based on the attributes used for determining the priority for MCX Users and Groups, subject to roaming capabilities and operator agreement, the MCX Service shall provide consistent and deterministic priority for all MCX Users that roam into Partner MCX Service Systems.
[R-6.8.1-015] The MCX Service shall provide a means for an MCX User to monitor the attributes used for determining priority of his/her communications and transmissions.
[R-6.8.1-016] The MCX Service shall provide a means for an authorized MCX User to monitor and affect a change of the attributes used for determining the priority of another MCX User's communications and transmissions.
3GPP TS 22.280 "Mission Critical Services Common Requirements (MCCoRe); Stage 1" (V18.2.0 (2022-06)) (22280-i20) clause 6.8.7 "MCX Service requirements specific to on-network use - MCX Service priority requirements - Application layer priorities"
6.8.7 Application layer priorities
6.8.7.1 Overview
Dispatchers from different critical communication organizations access the same networks and network resources. Depending on the event, the priority is given to an organization and/or a group rather than to another. For instance, in case of a fire priority is given to the fire brigades dealing with it, while in case of a criminal arrest priority is given to the police officers in charge of the arrest.
6.8.7.2 Requirements
[R-6.8.7.2-001] The MCX Service system shall be able to give application priorities to each communication according to the event in addition to the priority given according to groups.
[R-6.8.7.2-002] The 3GPP system shall inform the MCX Service system if a new MCX Service communication cannot be set up.
[R-6.8.7.2-003] The MCX Service system shall assign to each communication:
- an application layer pre-emption capability;
- a capability to be pre-empted; and
- an application layer priority value.
[R-6.8.7.2-004] If there are no MCX Service communications with the capability to be pre-empted, the MCX Service communications with the lowest application layer priorities may be terminated, even if the MCX Service communications are set as not pre-emptable.
[R-6.8.7.2-005] There shall be at least 8 and preferably 30 configurable levels of priority.
[R-6.8.7.2-006] The MCX Service shall enable the MCX User to request the priority level for each individual communication.
[R-6.8.7.2-007] The MCX Service system shall provide a mechanism that enables the MCX User to request any priority level up to the authorised priority level.
[R-6.8.7.2-008] The MCX Service system shall verify the priority level at communication setup against the maximum authorised priority level.
[R-6.8.7.2-009] The MCX Service system shall assign the defined priority level to a communication if the MCX User has not requested a priority level at setup.
[R-6.8.7.2-010] The MCX Service system shall assign the maximum authorised priority level to a communication if the MCX User has requested at setup a priority level higher than the maximum authorised priority level.
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 6.8.6 "MCPTT Service requirements specific to on-network use - MCPTT priority requirements - Application layer priorities"
6.8.6 Application layer priorities
6.8.6.1 Overview
Dispatchers from different critical communication organizations access the same networks and network resources. Depending on the event, the priority is given to an organization and/or a group rather than to another. For instance, in case of a fire priority is given to the fire brigades dealing with it, while in case of a criminal arrest priority is given to the police officers in charge of the arrest.
6.8.6.2 Requirements
[R-6.8.6.2-001] Void
[R-6.8.6.2-002] Void
[R-6.8.6.2-003] Void
[R-6.8.6.2-004] The MCPTT system may stop already established MCPTT calls with the capability to be pre-empted and a lower application layer priority to allow a new MCPTT call with pre-emption capability enabled for pre-emption to be established.
[R-6.8.6.2-005] Void
[R-6.8.6.2-006] Void
MCX Services Request Handling and Floor Control
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 4.1 "Mission Critical Push To Talk overview - General"
4.1 General
[...]
The MCPTT Service allows users to request the permission to talk (transmit voice/audio) and provides a deterministic mechanism to arbitrate between requests that are in contention (i.e., Floor control). When multiple requests occur, the determination of which user's request is accepted and which users' requests are rejected or queued is based upon a number of characteristics (including the respective priorities of the users in contention). MCPTT Service provides a means for a user with higher priority (e.g., MCPTT Emergency condition) to override (interrupt) the current talker. [...]
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 4.4 "Mission Critical Push To Talk overview - General handling of requests"
4.4 General handling of requests
Request handling is by no means specific only to MCPTT Service, but it plays a central role in its functionality.
Requests appear in the MCPTT Service in many forms and under many circumstances: e.g., requests for the floor during a call, requests for starting a call, requests for resources. Conceptually, requests are accompanied by priority information that is used in the arbitration, in case of contention; see also subclause 4.6 for a brief explanation and examples on how priority processing is modelled.
Upon arrival, a request is immediately granted, denied, or queued.
If queued, a request can be dropped due to queue overflow (i.e., too many items queued) or can be cancelled by an authorized user, who is usually the initiator of the request. Either way, the net result is that the request is denied.
When a request denial is communicated, the request may be re-requested either manually by user action or automatically. In the automatic case, while the request remains denied, it may be automatically repeated a configurable number of times where a minimum time interval between re-transmissions may also be applied.
There are many "queuing disciplines" possible that govern the placement of items in a queue and their subsequent removal from the queue: e.g., FIFO, priority order. Assuming that the queuing discipline chosen places the highest priority requests towards the top of the queue, the granted request is either, depending on the design and configuration, the front-most entry in the queue or the first entry counting from the top that can be satisfied by the available resources. For example, if the topmost entry in the queue is awaiting for ten GBR bearers of given characteristics to become available and the second entry in the queue is waiting for seven GBR bearers to become available, and at some point in time eight GBR bearers become available, then it is possible that the second request is granted ahead of the first one, which continues to wait. Alternatively, neither the first request nor the second request is granted and the wait continues until at least ten GBR bearers become available, at which time the first request is granted while the second request continues to wait.
3GPP TS 22.280 "Mission Critical Services Common Requirements (MCCoRe); Stage 1" (V18.2.0 (2022-06)) (22280-i20) clause 6.2.2 "MCX Service requirements specific to on-network use - MCX Service communications - Queuing"
6.2.2 Queuing
[R-6.2.2-001] The MCX Service shall prioritize the transmit request queue based on the type of communication (e.g., group, private), urgency of the communication (e.g., general group, MCX Service Emergency, Imminent Peril), attributes (e.g., priority level) of the MCX Service Group (if a group communication), and attributes (e.g., priority level) of the requesting MCX User.
[R-6.2.2-002] When prioritizing the transmit queue, the MCX Service may assign higher priority to communications of the MCX Service Groups and MCX Users operating within the boundaries of their jurisdictions, if known.
[R-6.2.2-003] When prioritizing the transmit queue, the MCX Service may assign higher priority to communications of the MCX Service Groups and MCX Users during hours of operation or while on duty, if known.
[R-6.2.2-004] The MCX Service shall allow MCX Users with queued requests for permission to transmit to cancel their requests.
[R-6.2.2-005] If an MCX Service Group Communication request to transmit has been queued, the MCX Service shall provide, upon request, that MCX User's current position in the queue.
[R-6.2.2-006] If a request for an MCX Service Group Communication is queued, the MCX Service shall provide an indication to the requester when the communication continues.
3GPP TS 22.280 "Mission Critical Services Common Requirements (MCCoRe); Stage 1" (V18.2.0 (2022-06)) (22280-i20) clause 6.19.1 "MCX Service requirements specific to on-network use - Additional MCX Service requirements - Communication rejection and queuing"
6.19.1 Communication rejection and queuing
Requests to transmit appear in MCX Services in many forms and under many circumstances. Normally, requests to transmit are accompanied by priority information that is used to arbitrate the decision to assign resources for the transmission amongst competing requests to transmit.
Upon arrival, a request to transmit is immediately granted, rejected, or queued.
If queued, a request to transmit is normally granted when conditions which caused the queue are removed, or it can be dropped automatically for a number of reasons, or it can be cancelled by an authorized user who is usually the initiator of the request to transmit.
When a request to transmit is rejected, it can be re-requested either manually by user action or automatically.
6.19.1.1 Requirements
[R-6.19.1.1-001] The MCX Service shall provide a mechanism to queue any MCX request to transmit.
[R-6.19.1.1-002] The MCX Service shall provide a mechanism to reject MCX request to transmit with a cause indication.
[R-6.19.1.1-003] The MCX Service shall notify the requesting MCX Participant and may notify one or more authorized users when a communication is queued, when a communication is rejected, when communications has started after being de-queued.
[R-6.19.1.1-004] The MCX Service shall provide a mechanism for an MCX User to remove its MCX request to transmit from the MCX request queue.
[R-6.19.1.1-005] The MCX Service shall provide a mechanism for an authorised user to remove another user’s MCX request to transmit from the MCX request queue.
[R-6.19.1.1-005a] The MCX Service shall provide a mechanism for an authorised user to clear the entire MCX request queue.
[R-6.19.1.1-006] An MCX Service User shall be notified when his request to transmit is removed from the MCX request queue.
[R-6.19.1.1-007] The MCX Service shall provide a mechanism for an MCX Administrator to configure service parameter(s) (e.g., timer) for automatic removal of an MCX request to transmit from any MCX request queue.
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 4.6.1 "Mission Critical Push To Talk overview - Overview of MCPTT priorities - MCPTT priority model": As in the above section 'MCX Services Priority over the Cellular Network'.
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 4.6.2 "Mission Critical Push To Talk overview - Overview of MCPTT priorities - Generic processing of priority information": As in the above section 'MCX Services Priority over the Cellular Network'.
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 4.6.3 "Mission Critical Push To Talk overview - Overview of MCPTT priorities - Handling of MCPTT priority information for Floor control"
Floor control is applied in the context of a single MCPTT Call and is triggered by a Participant request for the permission to transmit. Priority information accompanies each grant request.
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 6.2.3 "MCPTT Service requirements specific to on-network use - MCPTT calls - Floor control"
6.2.3 Floor control
6.2.3.1 General aspects
[R-6.2.3.1-001] The Floor control functionality in an MCPTT Service shall determine at a point in time which Participant(s) are allowed to transmit to other Participant(s).
[R-6.2.3.1-002] Receiving Participant(s) shall receive audio from one transmitting Participant. The only exception is if an MCPTT Group is configured to allow simultaneous Transmitting MCPTT Group Members in override.
[R-6.2.3.1-003] The MCPTT Service shall provide a mechanism for the MCPTT Administrator to configure the number (maximum of N9) of simultaneous audios received by an MCPTT User in a single MCPTT Group.
6.2.3.2 Requesting permission to transmit
[R-6.2.3.2-001] An authorized Participant shall be able to request to transmit to an MCPTT Group or an individual Participant.
[R-6.2.3.2-002] At call setup the MCPTT Service shall provide a notification, for example audio and/or visual, to the MCPTT Group Member attempting to transmit that there are no other Group Members who have affiliated to the MCPTT Group.
[R-6.2.3.2-003] The Floor control functionality shall determine the transmitting Participant(s) when there are simultaneous requests for permission to transmit within the same call.
[R-6.2.3.2-004] Following an MCPTT Request for permission to transmit on the Selected MCPTT Group, the Affiliated MCPTT Group Member that made and was granted the request shall be given an indication of being allowed to transmit.
[R-6.2.3.2-005] Following an MCPTT Request for permission to transmit on the Selected MCPTT Group, an Affiliated MCPTT Group Member that made and was not granted the request shall be given an indication that permission to transmit was rejected or queued.
[R-6.2.3.2-006] The depth of the Floor control queue shall be configurable.
[R-6.2.3.2-007] Following an MCPTT Private Call (with Floor control) request for permission to transmit, the MCPTT User that is allowed to transmit shall be given an indication that the user is allowed to transmit to the targeted MCPTT User.
[R-6.2.3.2-008] Following an MCPTT Private Call (with Floor control) request for permission to transmit, an MCPTT User that is not allowed to transmit shall be given an indication that the permission to transmit was rejected or queued.
[R-6.2.3.2-009] The MCPTT Service shall provide an indication to receiving Participants that the transmitting Participant is starting to transmit.
[R-6.2.3.2-010] The MCPTT Service shall provide a mechanism for an MCPTT Participant to remove its MCPTT Request from the Floor control queue.
[R-6.2.3.2-011] The MCPTT Service shall provide a mechanism for removal (i.e., request accepted, request denied, or expiration of a timer) of an MCPTT Request from the Floor control queue.
[R-6.2.3.2-012] The MCPTT Service shall provide a mechanism for the MCPTT Administrator to configure the parameter(s) of the Floor control queue for an MCPTT Group (i.e., timer).
6.2.3.3 Override
6.2.3.3.1 General aspects
[R-6.2.3.3.1-001] The MCPTT Service shall enable MCPTT Administrators to create a priority hierarchy for determining what Participants, Participant types, and urgent transmission types shall be granted a request to override an active MCPTT transmission.
[R-6.2.3.3.1-002] The MCPTT Service shall enable an MCPTT Administrator to configure which MCPTT Group transmission a Participant(s) receives, overriding and/or overridden for cases where an authorized Participant overrides an MCPTT transmission.
[R-6.2.3.3.1-003] The MCPTT Service shall enable the MCPTT Administrator to configure the MCPTT Group to allow only the overriding Participant to transmit or to allow both the overriding and overridden Participant to transmit.
[R-6.2.3.3.1-004] The MCPTT Service shall provide a mechanism for an MCPTT Administrator to configure MCPTT Private Calls (with Floor control) to allow only the overriding Participant to transmit or to allow both the overriding and overridden Participant to transmit.
[R-6.2.3.3.1-005] The priority hierarchy used for granting a request to override an active MCPTT transmission shall contain at least four (4) levels.
[R-6.2.3.3.1-006] The transmitting Participant shall be determined by the relative Floor control priorities of the Participants and Call type based on priority (e.g MCPTT Emergency).
[R-6.2.3.3.1-007] The MCPTT Service shall provide a mechanism for Participants, to override an active MCPTT transmission of a transmitting Participant when the priority level of the overriding Participant or Call type based on priority (e.g MCPTT Emergency) are ranked higher than the priority level of the transmitting Participant or Call type based on priority.
[R-6.2.3.3.1-008] If an authorized Participant overrides an MCPTT transmission, the MCPTT Service shall provide a means of notifying the overridden Participant(s) that the transmission has been overridden.
6.2.3.3.2 Override – one transmitting Participant
[R-6.2.3.3.2-001] If the MCPTT Group has been configured to only allow the overriding transmitting Participant, the MCPTT Service shall revoke the transmit permission of the overridden transmitting Participant.
6.2.3.3.3 Override – simultaneously Transmitting MCPTT Group Members
[R-6.2.3.3.3-001] If the MCPTT Group has been configured to allow both overriding and overridden transmitting Participants, authorized receiving Participants shall be enabled to listen to both the overriding and overridden Participant transmissions, dependent on configuration.
[R-6.2.3.3.3-002] The MCPTT Service shall allow successive overrides of an MCPTT Group Call when the request to override is made by an MCPTT User having a higher Floor control priority than the currently transmitting Participants.
[R-6.2.3.3.3-003] In the case of successive overrides, the MCPTT Service shall enable only two transmissions, one overriding transmission, from the highest priority MCPTT User, and one overridden transmission, chosen from among the two overridden Participants based upon configured rule(s). (i.e., this could be based simply on priority of user, it could be based on a policy that an overridden MCPTT Emergency transmission shall remain as the overridden transmission or a rule could be established that the MCPTT system shall not allow two dispatchers to be both the overriding and overridden transmitters.).
6.2.3.4 Terminating permission to transmit
[R-6.2.3.4-001] The MCPTT Service shall enable an authorized MCPTT User to terminate the permission to transmit of a transmitting Participant at any time.
[R-6.2.3.4-002] A transmitting Participant shall be able to indicate to the MCPTT Service that the Participant no longer wants to transmit.
NOTE: In this case audio stops being transmitted to the receiver Participant(s) until an authorized Participant sends a subsequent request for permission to transmit.
[R-6.2.3.4-003] The MCPTT Service shall provide an indication to receiving Participants that the transmitting Participant has finished transmitting.
6.2.3.5 Transmit time limit
[R-6.2.3.5-001] The MCPTT Service shall enable an MCPTT Administrator to configure the limit for the length of time that a Participant transmits from a single request to transmit.
[R-6.2.3.5-002] The Floor control functionality shall have a configurable limit for the length of time that a Participant transmits from a single request to transmit.
[R-6.2.3.5-003] The Floor control functionality shall provide an indication to the transmitting Participant that the Participant is within a configurable amount of time before his transmit time limit is reached.
[R-6.2.3.5-004] The Floor control functionality shall provide an indication to the transmitting Participant that the Participant's transmit time limit has been reached.
[R-6.2.3.5-005] The Floor control functionality shall remove the permission to transmit from the transmitting Participant when the Participant's transmit time limit has been reached.
6.2.3.6 Audio cut-in on designated MCPTT Groups
6.2.3.6.1 Overview
The audio cut-in feature applies to specially designated MCPTT Groups and results in Floor control for that group allowing any participant within the MCPTT Group to interrupt any other participant. In particular the audio cut-in feature means that the last Participant to request the floor is assigned the floor immediately and there is only ever one talker on the call at a particular point in time. Audio cut-in is often used for teams escorting VIPs where timeliness is essential to allow teams to react as quickly as possible.
Other than the difference in floor control logic, the MCPTT Groups configured to support audio cut-in behave in the same way as other MCPTT Groups with group management, affiliation, selection of a group, requesting the floor, the notifications received related to Floor control etc working in the same way.
6.2.3.6.2 Requirements
[R-6.2.3.6.2-001] The MCPTT Group shall be configurable to allow audio cut-in.
NOTE 1: MCPTT Groups configured for audio cut-in behave in the same way as MCPTT Groups not configured for audio cut-in in all other respects other than the Floor control logic described in this sub-clause.
[R-6.2.3.6.2-002] When an MCPTT Group has been configured to support audio cut-in, the Floor control functionality shall give the floor to the MCPTT Group Member that has selected that MCPTT Group and made the most recent request to transmit in that MCPTT Group.
NOTE 2: Requests to transmit that are received simultaneously will be addressed by manufacturer implementation.
[R-6.2.3.6.2-003] When an MCPTT Group has been configured to support audio cut-in the Floor control functionality shall restrict the number of talkers in the group to one.
[R-6.2.3.6.2-004] When an MCPTT Group has been designated to support audio cut-in the MCPTT Group shall not support any form of floor control queuing and associated functionality.
[R-6.2.3.6.2-005] When the current talker is interrupted by a request to transmit on an MCPTT Group supporting audio cut-in, the talk request of the interrupted talker shall end. NOTE 3: The interrupted talker must make a new request to transmit in order to transmit again.
[R-6.2.3.6.2-006] Void
[R-6.2.3.6.2-007] Void
6.2.3.6.3 Requesting permission to transmit
[R-6.2.3.6.3-001] An authorized Participant shall be able to request to transmit to an MCPTT Group configured to support audio cut-in.
[R-6.2.3.6.3-002] At call setup the MCPTT Service shall provide a notification, for example audio and/or visual, to the MCPTT Group Member attempting to transmit that there are no other Group Members who have affiliated to the MCPTT Group configured to support audio cut-in.
[R-6.2.3.6.3-003] Following an MCPTT Request for permission to transmit on the Selected MCPTT Group configured to support audio cut-in, the Affiliated MCPTT Group Member that made and was granted the request shall be given an indication of being allowed to transmit.
[R-6.2.3.6.3-004] The MCPTT Service shall provide an indication to receiving Participants that the transmitting Participant is starting to transmit on a group configured for audio cut-in.
6.2.3.6.4 Terminating permission to transmit
[R-6.2.3.6.4-001] The MCPTT Service shall enable an authorized MCPTT User to terminate the permission to transmit of a transmitting Participant at any time on a group configured for audio cut-in.
[R-6.2.3.6.4-002] A transmitting Participant shall be able to indicate to the MCPTT Service that the Participant no longer wants to transmit on a group configured for audio cut-in. NOTE: In this case audio stops being transmitted to the receiver Participant(s) until an authorized Participant sends a subsequent request for permission to transmit.
[R-6.2.3.6.4-003] The MCPTT Service shall provide an indication to receiving Participants that the transmitting Participant has finished transmitting on a group configured for audio cut-in.
6.2.3.6.5 Transmit time limit
[R-6.2.3.6.5-001] The MCPTT Service shall enable an MCPTT Administrator to configure the limit for the length of time that a Participant transmits from a single request to transmit on a group configured for audio cut-in.
[R-6.2.3.6.5-002] The Floor control functionality for a group configured for audio cut-in shall have a configurable limit for the length of time that a Participant transmits from a single request to transmit.
[R-6.2.3.6.5-003] The Floor control functionality for a group configured for audio cut-in shall provide an indication to the transmitting Participant that the Participant is within a configurable amount of time before his transmit time limit is reached.
[R-6.2.3.6.5-004] The Floor control functionality for a group configured for audio cut-in shall provide an indication to the transmitting Participant that the Participant's transmit time limit has been reached.
[R-6.2.3.6.5-005] The Floor control functionality for a group configured for audio cut-in shall remove the permission to transmit from the transmitting Participant when the Participant's transmit time limit has been reached.
6.2.3.7 MCPTT Groups configured for multi-talker control
6.2.3.7.1 Overview
The multi-talker control applies to designated MCPTT Groups and results in allowing several Participants talking simultaneously within the MCPTT Group. For example, Multi-talker control is used by railway communication e.g. during shunting operation.
Except for Floor control as specified in clauses 6.2.3.1, 6.2.3.2, 6.2.3.3 and 6.2.3.6 all other requirements specified in 6.2.3 floor control are applicable to MCPTT Groups configured to support multi-talker control.
When an MCPTT Group is configured for multi-talker control, the requirements listed below apply.
6.2.3.7.2 General aspects
[R-6.2.3.7.2-001] An MCPTT Group shall be configurable to allow multi-talker control.
[R-6.2.3.7.2-002] The MCPTT Service shall provide a mechanism for multiple MCPTT Users to talk simultaneously in an MCPTT Group configured for multi-talker control.
[R-6.2.3.7.2-003] The MCPTT Service shall determine which Participant(s) are allowed to transmit to all other Participant(s) in an MCPTT Group configured for multi-talker control.
[R-6.2.3.7.2-004] The MCPTT Service shall support all Participant(s) to receive audio from all other Participant(s) that are transmitting in an MCPTT Group configured for multi-talker control.
[R-6.2.3.7.2-005] The MCPTT Service shall provide a mechanism for the MCPTT Administrator to configure the maximum number of simultaneous talkers in an MCPTT Group configured for multi-talker control.
[R-6.2.3.7.2-006] The MCPTT Service shall allow an authorized MCPTT User to change the maximum number of simultaneous talkers at any time during a group call in an MCPTT Group configured for multi-talker control.
6.2.3.7.3 Requesting permission to transmit
[R-6.2.3.7.3-001] The MCPTT Service shall enable authorized Participants to request to transmit to an MCPTT Group configured for multi-talker control.
[R-6.2.3.7.3-002] At call setup the MCPTT Service shall provide a notification, for example audio and/or visual, to the MCPTT Group Member attempting to transmit that there are no other Group Members who have affiliated to the MCPTT Group configured for multi-talker control.
[R-6.2.3.7.3-003] The MCPTT Service shall determine the transmitting Participant(s) when there are simultaneous requests for permission to transmit within the same call for an MCPTT Group configured for multi-talker control.
[R-6.2.3.7.3-004] Following an MCPTT Request for permission to transmit on the Selected MCPTT Group configured for multi-talker control the MCPTT Service shall provide an Affiliated MCPTT Group Member that made and was granted the request an indication of being allowed to transmit.
6.2.3.7.4 Override
6.2.3.7.4.1 General aspects
[R-6.2.3.7.4.1-001] If the number of MCPTT Users requesting the permission to talk exceeds the maximum number of simultaneous talkers in an MCPTT Group configured for multi-talker control, the MCPTT Service shall apply the override mechanism.
[R-6.2.3.7.4.1-002] The MCPTT Service shall enable MCPTT Administrators to create a priority hierarchy for determining what Participants, Participant types, and urgent transmission types shall be granted a request to override an active MCPTT transmission on an MCPTT Group configured for multi-talker control.
[R-6.2.3.7.4.1-003] The priority hierarchy used for granting a request to override an active MCPTT transmission on a group configured for multi-talker control shall contain at least four (4) levels.
[R-6.2.3.7.4.1-004] The transmitting Participant onan MCPTT Group a group configured for multi-talker control shall be determined by the relative priorities of the Participants and Call type based on priority (e.g MCPTT Emergency).
[R-6.2.3.7.4.1-005] Transmission requests of Participants with insufficient relative priority shall be rejected.
[R-6.2.3.7.4.1-006] The MCPTT Service shall provide a mechanism for Participants, to override an active MCPTT transmission of a transmitting Participant when the priority level of the overriding Participant or Call type based on priority (e.g MCPTT Emergency) are ranked higher than the priority level of the transmitting Participant or Call type based on priority for an MCPTT Group configured for multi-talker control.
[R-6.2.3.7.4.1-007] If an authorized Participant overrides an MCPTT transmission, the MCPTT Service shall provide a means of notifying the overridden Participant(s) that the transmission has been overridden for an MCPTT Group configured for multi-talker control.
[R-6.2.3.7.4.1-008] The MCPTT Service shall revoke the transmit permission of the overridden transmitting Participant on an MCPTT Group configured for multi-talker control.
MCX Services Priority and QoS (Quality of Service) over the Cellular Networks
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 4.6.1 "Mission Critical Push To Talk overview - Overview of MCPTT priorities - MCPTT priority model"
4.6.1 MCPTT priority model
[...] MCPTT Priority and QoS (Quality of Service) are situational. The MCPTT Service is intended to provide a real-time priority and QoS experience for MCPTT calls, as public-safety users have significant dynamic operational conditions that determine their priority. For example, the type of incident a responder is serving or the responder's overall shift role needs to strongly influence a user's ability to obtain resources from the 3GPP system.
Another feature of a mission-critical service is the transparency of interactions between the users and the system. A first responder that needs to change the QoS of his communications is not to be distracted from his mission due to complicated UE (User Equipment) behaviors or service interactions. Instead, the service acts in an anticipatory and adaptive manner to provide the proper quality of experience to the user, automatically, or with simple and minimal interaction.
The mission-critical service is also expected to provide the ability to interface with public-safety systems (e.g., CAD (Computer-Aided Dispatch)) in order to determine the user's state (e.g., incident severity), environment, and conditions and to affect the most appropriate priority and QoS experience for the user.
The MCPTT Priority handling for on-network use for MCPTT Calls is conceptually modeled as shown in figure 4.6.1-1.
The conceptual model identifies three areas of prioritization: prioritization at the transport layer (3GPP System and UE), prioritization between and within calls, and inter-system prioritization. At the Application Layer a generic, network side, functional entity, "MCPTT Priority and QoS Control", processes with each request static, preconfigured information about users and groups participating in MCPTT, as well as dynamic (or situational) information about them. Based on the results of this processing, the "MCPTT Priority and QoS Control" provides information to and directs interactions with other functional entities, systems, or layers to ensure, to the extent possible, that from a quality of experience point of view, calls, and transmissions are handled properly in accordance to established policy rules.
The User Static Attributes include information categorizing the user, possibly by several criteria (e.g., first responder, second responder, supervisor, dispatcher, administrator), as well as jurisdictional boundaries and possibly a preconfigured system-wide individual priority level.
The Group Static Attributes include information about the nature/type of the group and the owning organization(s), the jurisdictional boundaries for transmitters and receivers within the group, the normal hours of operation for the group, pre-emption dispositions relative to other groups, and the default minimum priority of the group, i.e., the minimum priority characteristics that are provided to all the Participants in a group call associated with this group, regardless of their individual priority characteristics.
The User Dynamic Attributes include the user/Participant's operational status (e.g., on/off duty), his location, the type of incident (e.g., MCPTT Emergency or Imminent Peril) he might be involved in, and whether or not he initiated it, whether or not he is individually involved in a formally managed incident and if yes, the boundaries of the incident area, the incident severity and his assigned role in the resolution of the incident.
The Group Dynamic Attributes include the type of incident (e.g., MCPTT Emergency or Imminent Peril), if any, the group is currently handling and in case of involvement in a formally managed incident the boundaries of the incident area and the incident severity.
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 4.6.2 "Mission Critical Push To Talk overview - Overview of MCPTT priorities - Generic processing of priority information"
4.6.2 Generic processing of priority information
This functionality applies to MCPTT Call initiations and transmissions for the management of potentially contended resources (e.g., GBR bearers) and also for Floor control during an MCPTT Group Call.
Each request for exclusive access to resource(s) or for preferential treatment over a contending request arrives accompanied by priority information. This information stays associated with the companion request, whether the request is granted or is queued. The priority information is used for comparison between requests and facilitates the adding and removing of requests from queues and/or authorized interruption of service associated with a previously granted request, if still active. For each request, whether initially queued or not, the requesting party is informed (directly or indirectly) when his request is granted or denied. Other users/Participants are also notified of the disposition of a request and the notification includes the identity of the requestor, as needed. In addition, each requestor can be notified of the position of his request in the queue and he is allowed to cancel his requests while queued.
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 4.6.4 "Mission Critical Push To Talk overview - Overview of MCPTT priorities - Handling of MCPTT priority information for interactions at the transport layer"
4.6.4 Handling of MCPTT priority information for interactions at the transport layer
At the Transport Layer, the MCPTT Service uses 3GPP controls to adapt the overall behavior of the MCPTT System to the needs for resources and/or preferential treatment over other contenders, based on the priority information accompanying the request.
The following four controls are available, to be used as necessary, based on the phase of the MCPTT call:
-
3GPP System Access Controls;
-
UE Access Controls;
-
3GPP System Admission Controls; and
-
3GPP System Scheduling Controls.
3GPP System Access Controls and UE Access Controls are used to allow preferential treatment of public-safety UEs in situations of access congestion. The controls use Priority and QoS mechanisms (e.g., using mechanisms like Access Class Barring, Service Specific Access Control, Access Control for Circuit Switched Fallback, and Extended Access Barring).
3GPP System Admission Controls are used for the establishment and maintenance of the priority levels and of the pre-emption vulnerability and capability of bearers associated with transmissions and calls. At the start of an MCPTT call, the MCPTT Service requires bearers with proper ARP (Allocation and Retention Priority) and pre-emption characteristics to be in place prior to the call proceeding.
3GPP System Scheduling Controls (e.g., QCI (QoS Class Identifier) and bandwidth for the bearers) are used to assuring the appropriate QoS necessary for meeting the Participants' expectations in the perceived quality of the delivered information, primarily in terms of when the service starts and the real-time characteristics of the delivered traffic (e.g., perceived delay, choppiness, clarity).
3GPP TS 22.280 "Mission Critical Services Common Requirements (MCCoRe); Stage 1" (V18.2.0 (2022-06)) (22280-i20) clause 6.8 "MCX Service requirements specific to on-network use - MCX Service priority requirements"
6.8 MCX Service priority requirements
6.8.1 [...]
6.8.2 3GPP System Access Controls: [R-6.8.2-001] The 3GPP system shall, subject to operator policy, provide a means for the MCX Service to influence the modification of the access parameters used by the network to admit MCX UEs within a defined area. NOTE: It is believed that the existing UE network access mechanisms could be utilized to meet the above requirement.
6.8.3 3GPP System Admission Controls: [R-6.8.3-001] The 3GPP system shall, subject to operator policy, provide a means for the MCX Service to influence the selection and/or modification of admission and retention controls for the bearers assigned or about to be assigned to an MCX UE based on the MCX User's and MCX Service Group attributes used for the priority determination. NOTE: It is believed that the existing 3GPP mechanisms for network priority and QoS could be utilized to meet the above requirement.
6.8.4 3GPP System Scheduling Controls: [R-6.8.4-001] The 3GPP system shall, subject to operator policy, provide a means for the MCX Service to influence the selection and/or modification of the bearer scheduling controls for the bearers assigned or about to be assigned to an MCX UE based on the MCX User's and MCX Service Group attributes used for the priority determination. NOTE: It is believed that the existing 3GPP mechanisms for network priority and QoS could be utilized to meet the above requirement.
6.8.5 UE Access Controls: [R-6.8.5-001] The MCX Service shall allow the MCX UE to temporarily modify selected 3GPP system access parameters, according to configuration established by an MCX Service Administrator in agreement with the operator's policy. NOTE: It is believed that the existing network access mechanisms, e.g., ACDC [Application specific Congestion control for Data Communication] (see 3GPP TS 22.011 [applicable to 2G GSM, 3G UMTS, 4G LTE] and 3GPP TS 23.122 [applicable to 2G GSM, 3G UMTS, 4G LTE, 5GS]), could be utilized to meet the above requirement.
3GPP System Access Controls
TCCA White Paper "Public Safety Prioritisation on Commercial Networks" June 2019 §5.1 "Available Prioritisation Mechanisms in 4G on shared network - Access Class Barring (ABR)": ACB prevents congestion at signaling level (random access procedure) when too many UEs try simultaneously to get a radio resource assigned (RRC (Radio Resource Control) connection). [...] The network can automatically activate ACB based on certain overload thresholds at a cell level. [...]
3GPP TS 22.179 "Mission Critical Push to Talk (MCPTT); Stage 1" (V17.1.0 (2022-03)) (22179-h10) clause 6.8.1 "MCPTT Service requirements specific to on-network use - MCPTT priority requirements - General": [R-6.8.1-002] The MCPTT Service shall provide an access control mechanism to support multiple Access Priorities to prioritize MCPTT MO (Mobile Originated) call initiation attempts, depending on their Access Priorities.
3GPP TS 22.011 "Service accessibility" (V17.0.0 (2019-12)) (22011-h00) (applicable to 2G GSM, 3G UMTS, 4G LTE) clause 4.2 "Access control - Allocation": All UEs are members of one out of ten randomly allocated mobile populations, defined as Access Classes 0 to 9. The population number is stored in the SIM/USIM. In addition, UEs may be members of one or more out of five special categories (Access Classes 11 to 15), also held in the SIM/USIM. These are allocated to specific high-priority users as follows. (The enumeration is not meant as a priority sequence):
• Access Class 11: for PLMN (Public Land Mobile Network) Use;
• Access Class 12: for Security Services;
• Access Class 13: for Public Utilities (e.g. water/gas suppliers);
• Access Class 14: for Emergency Services;
• Access Class 15: for PLMN Staff
3GPP TS 22.011 "Service accessibility" (V17.0.0 (2019-12)) (22011-h00) (applicable to 2G GSM, 3G UMTS, 4G LTE) clause 4.3.1 "Access control - Operation - ACB (Access Class Barring)": If the UE is a member of at least one Access Class that corresponds to the permitted classes as signaled over the air interface, and the Access Class is applicable in the serving network, access attempts are allowed. [...] Also, the serving network can indicate that UEs are restricted to perform location registration, although common access is permitted. [...] Note: The network operator can take the network load into account when allowing UEs access to the network. [...]
3GPP TS 22.011 "Service accessibility" (V17.0.0 (2019-12)) (22011-h00) (applicable to 2G GSM, 3G UMTS, 4G LTE) clause 4.4 "Access control - Emergency Calls": An additional control bit known as "Access Class 10" is also signaled over the air interface to the UE. This indicates whether or not network access for Emergency Calls is allowed for UEs with Access Classes 0 to 9 or without an IMSI. For UEs with Access Classes 11 to 15, Emergency Calls are not allowed if both "Access class 10" and the relevant Access Class (11 to 15) are barred. Otherwise, Emergency Calls are allowed.
3GPP System Admission Controls
TCCA White Paper "Public Safety Prioritisation on Commercial Networks" June 2019 §5.2 "Available Prioritisation Mechanisms in 4G on shared network - Admission control through Allocation and Retention Priority (ARP)":
Admission control prevents congestion at Evolved Packet System (EPS) bearer level, once Radio Resource Control (RRC) is established.
3GPP has defined different levels of Allocation and Retention Priority (ARP) that are assigned to the EPS bearers. The range of the ARP priority level is 1 to 15 with 1 as the highest level of priority. An existing lower-priority bearer can be pre-empted by a higher-priority bearer, if the lower-priority bearer has pre-emption vulnerability set and the higher-priority bearer has pre-emption capability set.
ARP value is valid for both GBR (Guaranteed Bit Rate) bearers and non-GBR bearers. A typical Public-Safety example could be prioritization of GBR bearer for MCPTT service over regular Voice over LTE (VoLTE) call or any other bearer. The dedicated GBR bearer for MCPTT call could have ARP priority level 3 and dedicated GBR bearer for VoLTE could have ARP priority level 10. If all GBR resources were consumed in a cell and pre-emption enabled, then a new MCPTT call could pre-empt general internet traffic or video streaming.
ARP is part of QoS parameters. For default bearers the ARP priority is included in subscription data in the Home Subscriber Server (HSS) for each allowed Access Point Name (APN). Pre-emption capability and vulnerability for default bearers are set by the Mobility Management Entity (MME) according to operator policy. ARP priority and pre-emption settings can be also modified by the Packet Data Network Gateway (P-GW) based on interaction with the Policy and Charging Rules Function (PCRF). ARP for dedicated bearers is set by P-GW based on subscription or based on interaction with PCRF.
3GPP TS 23.401 "GPRS enhancements for E-UTRAN access" (V17.5.0 (2022-06)) (23401-h50) clause 4.3.2.1 "Architecture model and concepts - High-level functions - Network access control functions - General": Network access is the means by which a user is connected to the Evolved Packet Core system.
3GPP TS 23.401 "GPRS enhancements for E-UTRAN access" (V17.5.0 (2022-06)) (23401-h50) clause 4.3.2.4 "Architecture model and concepts - High-level functions - Network access control functions - Admission control function": The purpose of admission control is to determine if the requested resources are available, and then reserve those resources.
3GPP TS 23.401 "GPRS enhancements for E-UTRAN access" (V17.5.0 (2022-06)) (23401-h50) clause 4.7.3 "Architecture model and concepts - Overall QoS concept - Bearer level QoS parameters":
The EPS bearer QoS profile includes the parameters QCI (QoS Class Identifier), ARP, GBR (Guaranteed Bit Rate) and MBR (Maximum Bit Rate), described in this clause. This clause also describes QoS parameters which are applied to an aggregated set of EPS Bearers: APN(Access Point Name)-AMBR(Aggregate Maximum Bit Rate) and UE-AMBR.
Each EPS bearer (GBR and Non-GBR) is associated with the following bearer-level QoS parameters:
- QoS Class Identifier (QCI);
- Allocation and Retention Priority (ARP).
[...]
NOTE 2: When required by operator policy, the eNodeB can be configured to also use the ARP priority level in addition to the QCI to control bearer level packet forwarding treatment in the eNodeB for SDFs [Service Data Flows] having high priority ARPs.
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The ARP shall contain information about the priority level (scalar), the pre-emption capability (flag) and the pre-emption vulnerability (flag). The primary purpose of ARP is to decide whether a bearer establishment / modification request can be accepted or needs to be rejected due to resource limitations (typically available radio capacity for GBR bearers). The priority level information of the ARP is used for this decision to ensure that the request of the bearer with the higher priority level is preferred. In addition, the ARP can be used (e.g. by the eNodeB) to decide which bearer(s) to drop during exceptional resource limitations (e.g. at handover). The pre-emption capability information of the ARP defines whether a bearer with a lower ARP priority level should be dropped to free up the required resources. The pre-emption vulnerability information of the ARP defines whether a bearer is applicable for such dropping by a pre-emption capable bearer with a higher ARP priority level.
Once a bearer has been successfully established, the packet handling (e.g. scheduling and rate control) within the eNodeB, PDN GW, and Serving GW should be solely determined by the following EPS bearer QoS parameters: QCI, GBR and MBR, and by the AMBR parameters. However, when required by operator policy, the eNodeB can be configured to also use a bearer's ARP priority level in addition to the QCI to determine the relative priority of the SDFs [Service Data Flows] for packet handling (e.g. scheduling and rate control) in the eNodeB as defined in TS 23.203 "Policy and Charging Control Architecture" (applicable to 2G GSM, 3G UMTS, 4G LTE) clause 6.1.7.2 ["Functional description - Overall description - Standardized OoS characteristics - Standardized QCI characteristics"]. This configuration applies only for bearers with high-priority ARPs as defined in TS 23.203 clause 6.1.7.3.
The ARP priority level may be used in addition to the QCI to determine the transport level packet marking, e.g. to set the DiffServ Code Point. The ARP is not included within the EPS QoS Profile sent to the UE.
NOTE 3: The ARP should be understood as "Priority of Allocation and Retention"; not as "Allocation, Retention, and Priority".
NOTE 4: Video telephony is one use case where it may be beneficial to use EPS bearers with different ARP values for the same UE. In this use case an operator could map voice to one bearer with a higher ARP, and video to another bearer with a lower ARP. In a congestion situation (e.g. cell edge) the eNodeB can then drop the "video bearer" without affecting the "voice bearer". This would improve service continuity.
NOTE 5: The ARP may also be used to free up capacity in exceptional situations, e.g. a disaster situation. In such a case the eNodeB may drop bearers with a lower ARP priority level to free up capacity if the pre-emption vulnerability information allows this.
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The HSS [Home Subscriber Server] defines, for each PDN subscription context, the 'EPS subscribed QoS profile' which contains the bearer level QoS parameter values for the default bearer (QCI and ARP) and the subscribed APN-AMBR value. The subscribed ARP shall be used to set the priority level of the EPS bearer parameter ARP for the default bearer while the pre-emption capability and the pre-emption vulnerability information for the default bearer are set based on MME operator policy. In addition, the subscribed ARP shall be applied by the P-GW for setting the ARP priority level of all dedicated EPS bearers of the same PDN connection unless a different ARP priority level setting is required (due to P-GW configuration or interaction with the PCRF).
NOTE 7: The ARP parameter of the EPS bearer can be modified by the P-GW (e.g. based on interaction with the PCRF due to e.g. MPS [Multimedia Priority Service] user-initiated session) to assign the appropriate pre-emption capability and the pre-emption vulnerability setting.
The ARP pre-emption vulnerability of the default bearer should be set appropriately to minimize the risk of unnecessary release of the default bearer.
3GPP TS 23.203 "Policy and Charging Control Architecture" (V17.1.0 (2021-06)) (23203-h10) (applicable to 2G GSM, 3G UMTS, 4G LTE) §6.1.7.1 "Functional description - Overall description - Standardized QoS characteristics - General": The service level (i.e., per SDF (Service Data Flow) or per SDF aggregate) QoS parameters are QCI, ARP, GBR, and MBR. [...] For the same IP-CAN (IP-Connectivity Access Network) session multiple SDFs with the same QCI and ARP can be treated as a single traffic aggregate which is referred to as an SDF aggregate. An SDF is a special case of an SDF aggregate. [...]
3GPP TS 23.203 "Policy and Charging Control Architecture" (V17.1.0 (2021-06)) (23203-h10) (applicable to 2G GSM, 3G UMTS, 4G LTE) clause 6.1.7.3 "Functional description - Overall description - Standardized QoS characteristics - Allocation and Retention Priority characteristics":
The QoS parameter ARP contains information about the priority level, the pre-emption capability and the pre-emption vulnerability.
The priority level defines the relative importance of a resource request. This allows deciding whether a bearer establishment or modification request can be accepted or needs to be rejected in case of resource limitations (typically used for admission control of GBR traffic). It can also be used to decide which existing bearers to pre-empt during resource limitations.
NOTE 1: The ARP priority level can be used in addition to the QCI to determine the transport level packet marking, e.g. to set the DiffServ Code Point of the associated EPS bearer, as described in TS 23.401.
NOTE 2: When required by operator policy, the eNodeB can be configured to use the ARP priority level in addition to QCI priority level to control the packet forwarding treatment for SDFs [Service Data Flows] having high-priority ARPs.
The range of the ARP priority level is 1 to 15 with 1 as the highest level of priority. The ARP priority levels 1-8 should only be assigned to resources for services that are authorized to receive prioritized treatment within an operator domain (i.e. that are authorized by the serving network). The ARP priority levels 9-15 may be assigned to resources that are authorized by the home network and thus applicable when a UE is roaming.
NOTE 3: This ensures that future releases may use ARP priority level 1-8 to indicate e.g. emergency and other priority services within an operator domain in a backward compatible manner. This does not prevent the use of ARP priority level 1-8 in roaming situation in case appropriate roaming agreements exist that ensure a compatible use of these priority levels.
The pre-emption capability information defines whether a service data flow can get resources that were already assigned to another service data flow with a lower priority level.
The pre-emption vulnerability information defines whether a service data flow can lose the resources assigned to it in order to admit a service data flow with higher priority level.
The pre-emption capability and the pre-emption vulnerability can be either set to 'yes' or 'no'.
3GPP System Scheduling Controls
TCCA White Paper "Public Safety Prioritisation on Commercial Networks" June 2019 §5.3 "Available Prioritisation Mechanisms in 4G on shared network - Traffic scheduling":
Every default and dedicated EPS bearer has a QoS Class Identifier (QCI), which defines the resource type (GBR or non-GBR), latency target, packet loss rate and priority level for scheduling.
The original 3GPP Release 8 specified standard GBR QCIs 1-4 and non-GBR QCIs 5-9.
3GPP Release 12 added additional QCIs for Public-Safety applications. GBR QCIs 65 and 66 are respectively for mission-critical PTT and non-mission-critical PTT. Non-GBR QCI 69 is for mission-critical signaling and non-GBR QCI 70 is for mission-critical data. MCPTT service will use QCI 69 bearer for signaling and QCI 65 for voice media. This is similar to VoLTE service, which uses QCI 5 for Session Initiation Protocol (SIP) signaling and QCI 1 for voice media. With these new QCIs PS users get priority scheduling for MCPTT even over the VoLTE service.
3GPP Release 15 added QCI 67 for MCVideo.
3GPP TS 23.401 "GPRS enhancements for E-UTRAN access" (V17.5.0 (2022-06)) (23401-h50) clause 4.7.3 "Architecture model and concepts - Overall QoS concept - Bearer level QoS parameters":
The EPS bearer QoS profile includes the parameters QCI (QoS Class Identifier), ARP, GBR (Guaranteed Bit Rate) and MBR (Maximum Bit Rate), described in this clause. This clause also describes QoS parameters which are applied to an aggregated set of EPS Bearers: APN(Access Point Name)-AMBR(Aggregate Maximum Bit Rate) and UE-AMBR.
Each EPS bearer (GBR and Non-GBR) is associated with the following bearer-level QoS parameters:
- QoS Class Identifier (QCI);
- Allocation and Retention Priority (ARP).
A QCI is a scalar that is used as a reference to access node-specific parameters that control bearer level packet forwarding treatment (e.g. scheduling weights, admission thresholds, queue management thresholds, link layer protocol configuration, etc.), and that have been pre-configured by the operator owning the access node (e.g. eNodeB). A one-to-one mapping of standardized QCI values to standardized characteristics is captured in TS 23.203.
NOTE 1: On the radio interface and on S1, each PDU [Protocol Data Unit] (e.g. RLC [Radio Link Control] PDU or GTP-U [GPRS Tunnelling Protocol for User Plane] PDU) is indirectly associated with one QCI via the bearer identifier carried in the PDU header. The same applies to the S5 and S8 interfaces if they are based on GTP.
NOTE 2: When required by operator policy, the eNodeB can be configured to also use the ARP priority level in addition to the QCI to control bearer level packet forwarding treatment in the eNodeB for SDFs [Service Data Flows] having high priority ARPs.
[...]
Once a bearer has been successfully established, the packet handling (e.g. scheduling and rate control) within the eNodeB, PDN GW, and Serving GW should be solely determined by the following EPS bearer QoS parameters: QCI, GBR and MBR, and by the AMBR parameters. However, when required by operator policy, the eNodeB can be configured to also use a bearer's ARP priority level in addition to the QCI to determine the relative priority of the SDFs [Service Data Flows] for packet handling (e.g. scheduling and rate control) in the eNodeB as defined in TS 23.203 clause 6.1.7.2. This configuration applies only for bearers with high-priority ARPs as defined in TS 23.203 clause 6.1.7.3.
[...]
The HSS [Home Subscriber Server] defines, for each PDN subscription context, the 'EPS subscribed QoS profile' which contains the bearer level QoS parameter values for the default bearer (QCI and ARP) and the subscribed APN-AMBR value.
[...]
3GPP TS 23.203 "Policy and Charging Control Architecture" (V17.1.0 (2021-06)) (23203-h10) (applicable to 2G GSM, 3G UMTS, 4G LTE) clause 6.1.7.1 "Functional description - Overall description - Standardized QoS characteristics - General":
The service level (i.e., per SDF (Service Data Flow) or per SDF aggregate) QoS parameters are QCI, ARP, GBR, and MBR. [...] For the same IP-CAN (IP-Connectivity Access Network) session multiple SDFs with the same QCI and ARP can be treated as a single traffic aggregate which is referred to as an SDF aggregate. An SDF is a special case of an SDF aggregate. [...]
3GPP TS 23.203 "Policy and Charging Control Architecture" (V17.1.0 (2021-06)) (23203-h10) (applicable to 2G GSM, 3G UMTS, 4G LTE) clause 6.1.7.2 "Functional description - Overall description - Standardized QoS characteristics - Standardized QCI characteristics":
Standardized characteristics, associated with standardized QCI values, describe the packet forwarding treatment that an SDF aggregate receives edge-to-edge between the UE and the PCEF (Policy and Charging Enforcement Function) in terms of the following performance characteristics:
1 Resource Type (GBR or Non-GBR);
2 Priority;
3 Packet Delay Budget;
4 Packet Error Loss Rate;
5 [...];
6 [...].
The standardized characteristics are not signalled on any interface. They should be understood as guidelines for the pre-configuration of node specific parameters for each QCI. The goal of standardizing a QCI with corresponding characteristics is to ensure that applications / services mapped to that QCI receive the same minimum level of QoS in multi-vendor network deployments and in case of roaming. [...]
Table 6.1.7-A "Standardized QCI characteristics"
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QCI: 65 - Resource Type: GBR - Priority Level: 0.7 - Packet Delay Budget: 75 ms - Packet Error Loss Rate: 10^(-2) - Example Services: Mission Critical Push To Talk voice (MCPTT) user plane;
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QCI: 67 - Resource Type: GBR - Priority Level: 1.5 - Packet Delay Budget: 100 ms - Packet Error Loss Rate: 10^(-3) - Example Services: Mission Critical Video (MCVideo) user plane;
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QCI: 69 - Resource Type: Non-GBR - Priority Level: 0.5 - Packet Delay Budget: 60 ms - Packet Error Loss Rate: 10^(-6) - Example Services: Mission Critical delay sensitive signalling (e.g., MCPTT signalling, MCVideo signalling);
QCI: 70 - Resource Type: Non-GBR - Priority Level: 5.5 - Packet Delay Budget: 200 ms - Packet Error Loss Rate: 10^(-6) - Example Services: Mission Critical Data (MCData) (e.g. Video (Buffered Streaming) TCP-based (e.g., www, e-mail, chat, ftp, p2p file sharing, progressive video, etc.))
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The Resource Type determines if dedicated network resources related to a service or bearer level Guaranteed Bit Rate (GBR) value are permanently allocated (e.g. by an admission control function in a radio base station). GBR SDF aggregates are therefore typically authorized "on demand" which requires dynamic policy and charging control. A Non GBR SDF aggregate may be pre-authorized through static policy and charging control.
[...]
The Packet Delay Budget (PDB) defines an upper bound for the time that a packet may be delayed between the UE and the PCEF. For a certain QCI the value of the PDB is the same in uplink and downlink. The purpose of the PDB is to support the configuration of scheduling and link layer functions (e.g. the setting of scheduling priority weights and HARQ (Hybrid Automatic Repeat ReQuest) target operating points). Except for QCIs 82 and 83, the PDB shall be interpreted as a maximum delay with a confidence level of 98 percent. [...]
NOTE 1: The PDB denotes a "soft upper bound" in the sense that an "expired" packet, e.g. a link layer SDU that has exceeded the PDB, does not need to be discarded (e.g. by RLC (Radio Link Control) in E-UTRAN). The discarding (dropping) of packets is expected to be controlled by a queue management function, e.g. based on pre-configured dropping thresholds.
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Services using a Non-GBR QCI should be prepared to experience congestion-related packet drops, and, except for QCI 80, 98 percent of the packets that have not been dropped due to congestion should not experience a delay exceeding the QCI's PDB. This may for example occur during traffic load peaks or when the UE becomes coverage limited. See Annex J for details. Packets that have not been dropped due to congestion may still be subject to non-congestion-related packet losses (see PELR [Packet Error Loss Rate] below). [...]
Except for services using QCI 82 or 83 services using a GBR QCI and sending at a rate smaller than or equal to GBR can in general assume that congestion-related packet drops will not occur, and 98 percent of the packets shall not experience a delay exceeding the QCI's PDB. Exceptions (e.g. transient link outages) can always occur in a radio access system which may then lead to congestion-related packet drops even for services using a GBR QCI and sending at a rate smaller than or equal to GBR. Packets that have not been dropped due to congestion may still be subject to non-congestion-related packet losses (see PELR [Packet Error Loss Rate] below). [...]
Every QCI (GBR and Non-GBR) is associated with a Priority level (see Table 6.1.7). The lowest Priority level value corresponds to the highest Priority. The Priority levels shall be used to differentiate between SDF aggregates of the same UE, and it shall also be used to differentiate between SDF aggregates from different UEs. Via its QCI an SDF aggregate is associated with a Priority level and a PDB. Scheduling between different SDF aggregates shall primarily be based on the PDB. If the target set by the PDB can no longer be met for one or more SDF aggregate(s) across all UEs that have sufficient radio channel quality then the QCI Priority level shall be used as follows: in this case a scheduler shall meet the PDB of an SDF aggregate on QCI Priority level N in preference to meeting the PDB of SDF aggregates on next QCI Priority level greater than N, until the priority N SDF aggregate's GBR (in case of a GBR SDF aggregate) has been satisfied.
Other aspects related to the treatment of traffic exceeding an SDF aggregate's GBR are out of scope of this specification.
When required by operator policy, the eNodeB can be configured to use the ARP priority level in addition to the QCI priority level to determine the relative priority of the SDFs in meeting the PDB of an SDF aggregate. This configuration applies only for high-priority ARPs as defined in clause 6.1.7.3.
NOTE 4: The definition (or quantification) of "sufficient radio channel quality" is out of the scope of 3GPP specifications.
NOTE 5: In case of E-UTRAN a QCI's Priority level, and when required by operator policy, the ARP priority level may be used as the basis for assigning the uplink priority per Radio Bearer (see TS 36.300 for details).
The Packet Error Loss Rate (PELR) defines an upper bound for the rate of SDUs (Service Data Units) (e.g. IP packets) that have been processed by the sender of a link layer protocol (e.g. RLC (Radio Link Control) in E-UTRAN) but that are not successfully delivered by the corresponding receiver to the upper layer (e.g. PDCP [Packet Data Convergence Protocol] in E-UTRAN). Thus, the PELR defines an upper bound for a rate of non-congestion-related packet losses. The purpose of the PELR is to allow for appropriate link layer protocol configurations (e.g. RLC [Radio Link Control] and HARQ [Hybrid Automatic Repeat ReQuest] in E-UTRAN). For a certain QCI the value of the PELR is the same in uplink and downlink.
NOTE 6: The characteristics PDB and PELR are specified only based on application / service level requirements, i.e., those characteristics should be regarded as being access agnostic, independent from the roaming scenario (roaming or non-roaming), and independent from operator policies.
QoS Dynamic modification
TCCA White Paper "Public Safety Prioritisation on Commercial Networks" June 2019 §5.4 "Available Prioritisation Mechanisms in 4G on shared network - QoS Dynamic modification":
Default EPS bearers have QoS defined in HSS [Home Subscriber Server] (QCI, ARP, Maximum Bit Rate (MBR) plus Aggregated Maximum Bit Rate (AMBR)). It is possible to dynamically modify the QoS of EPS bearers including default bearers. This can be achieved by having a PS application (e.g. a dispatcher application in a PS control room) that triggers policy change via PCRF. A less sophisticated option is also possible where predefined rules per traffic type are defined for example.
So, the scenario for dynamic priority level for PS users is possible with bearer QoS modification. PS users could for example have QCI 6 with ARP priority 8 for generic data connection normally and in the case of an emergency mission the data connection QoS could be modified to QCI 70 and ARP priority 6.
3GPP TS 23.401 "GPRS enhancements for E-UTRAN access" (V17.5.0 (2022-06)) (23401-h50) clause 4.7.3 "Architecture model and concepts - Overall QoS concept - Bearer level QoS parameters": As above.
3GPP TS 23.203 "Policy and Charging Control Architecture" (V17.1.0 (2021-06)) (23203-h10) (applicable to 2G GSM, 3G UMTS, 4G LTE) clause 6.1.7.1 "Functional description - Overall description - Standardized QoS characteristics - General":
The service level (i.e., per SDF (Service Data Flow) or per SDF aggregate) QoS parameters are QCI, ARP, GBR, and MBR. [...] For the same IP-CAN (IP-Connectivity Access Network) session multiple SDFs with the same QCI and ARP can be treated as a single traffic aggregate which is referred to as an SDF aggregate. An SDF is a special case of an SDF aggregate. [...]