3 Definitions and abbreviations
22.1793GPPMission Critical Push to Talk (MCPTT)Release 17Stage 1TS
3.1 Definitions
For the purposes of the present document, the terms and definitions given in TR 21.905 [1] and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905 [1]. Definitions provided in 3GPP TS 22.280 [15] also apply to this specification.
Affiliated MCPTT Group Member: An MCPTT Group Member who has indicated an interest in the group and is prepared to receive and/or transmit Group Communications from/to the particular MCPTT Group.
Automatic Commencement Private Call: A Private Call in which the initiation of the Private Call does not require any action on the part of the receiving MCPTT User.
Broadcast Group Call: A group call where the initiating MCPTT User expects no response from the other MCPTT Users, so that when his transmission is complete, so is the call.
Call Commencement Mode: This is a setting that determines the conditions under which a call is started.
Dispatcher: An MCPTT User who participates in MCPTT communications for command and control purposes.
Floor control: An arbitration system in an MCPTT Service that determines who has the authority to transmit (talk) at a point in time during an MCPTT call.
Group-Broadcast Group: A collection of groups defined by the MCPTT Administrator (e.g., representing a particular organizational structure) and intended to be the recipients of Broadcast Group Calls.
Group Regroup: The temporary combining of a multiplicity of groups into a single group.
Hang Time: A configurable maximum length of the inactivity (silence) period between consecutive MCPTT transmissions within the same call.
Imminent Peril Call: An urgent MCPTT Group call that highlights the potential of death or serious injury, but is less critical than an MCPTT Emergency Group Call. For example a call prioritized in the event of immediate threat to any human life such as resulting from an MCPTT User’s observation of or engagement in a situation involving imminent peril to the general public (e.g., a forest fire about to encircle campers, tanker truck ready to explode near a school, casualties at the scene of a car bombing).
In-progress Emergency: An emergency condition for a group that has been accepted by the MCPTT Service, but has not yet been cancelled by an authorized user.
In-progress Imminent Peril: An imminent peril condition for a group that has been accepted by the MCPTT Service and has not yet been cancelled by an authorized MCPTT User.
Late call entry: An Affiliated MCPTT Group Member joins in an in progress MCPTT Group Call.
Location: The current physical location (i.e., co-ordinates plus estimated accuracy and timestamp) of the MCPTT UE that can be cross-referenced to a map.
Losing audio: Audio of an overridden talker that is routed to selected authorized MCPTT Users.
Manual Commencement Private Call: A Private Call in which the initiation of the Private Call requires the receiving MCPTT User to perform some action to accept or reject the Private Call setup.
MCPTT Administrator: An individual authorized to control parameters of the MCPTT Service for an organization including, for example, user and group definition, user/group aliases, user priorities, group membership/priorities/hierarchies, security and privacy controls.
MCPTT Emergency Alert: A notification from the MCPTT UE to the MCPTT Service that the MCPTT User has an emergency condition.
MCPTT Emergency Group Call: An urgent MCPTT Group call that highlights the potential of death or serious injury to the initiator.
MCPTT Emergency Private Call: An urgent MCPTT Private Call that highlights the potential of death or serious injury to the initiator.
MCPTT Emergency State: A heightened condition of alarm for an MCPTT User indicating a need for immediate assistance due to a personal life-threatening situation.
MCPTT Group: A defined set of MCPTT Users identified independently of transport or network type.
MCPTT Group Member: An MCPTT User who has been authorized to participate in Group Communications of a particular MCPTT Group.
MCPTT Request: The action taken by an MCPTT User to request the permission to transmit voice on a call.
MCPTT Service: A Push To Talk communication service supporting applications for Mission Critical Organizations and mission critical applications for other businesses and organizations (e.g., utilities, railways) with fast setup times, high availability, reliability and priority handling.
MCPTT system: The collection of applications, services, and enabling capabilities required to provide Mission Critical Push To Talk for a Mission Critical Organization.
MCPTT UE: A UE that enables an MCPTT User to participate in MCPTT Service.
MCPTT User: A user of an MCPTT Service, who has a device with the capability to participate in MCPTT Services.
MCPTT User Profile: The set of information that allows an MCPTT User to employ the MCPTT Service in a given role and/or from a given MCPTT device.
Mission Critical Push To Talk: A group communication service with fast setup times, ability to handle large groups, strong security and priority handling.
Off-Network MCPTT Service: The collection of functions and capabilities required to provide MCPTT using ProSe Discovery and the ProSe Communication path for MCPTT Users using Public Safety ProSe-enabled UEs as a direct communication between UEs.
Partner MCPTT System: Allied MCPTT system that provides MCPTT Services to an MCPTT User based on the MCPTT User Profile that is defined in the Primary MCPTT System of that MCPTT User.
Pre-emption: The act of terminating on-going calls in order to free up resources for a higher priority call request.
Primary MCPTT System: MCPTT system where the MCPTT User Profile of an MCPTT User is defined.
Private Call: A call between a pair of MCPTT Users using the MCPTT Service with or without MCPTT Floor control.
Project 25 RFSS: A Project 25 Radio Frequency (RF) Subsystem as defined in TSB-102-B [2].
Receiving MCPTT Group Member: An Affiliated MCPTT Group Member who is currently receiving Group Communication from an MCPTT Group.
Selected MCPTT Group: The MCPTT Group that a particular Affiliated MCPTT Group Member uses for transmission.
System Call: A special case of a Broadcast Group Call that is transmitted to all users in a dynamically defined geographic area.
Transmitting MCPTT Group Member: An Affiliated MCPTT Group Member who is currently transmitting a Group Communication to a Selected MCPTT Group.
User-Broadcast Group: A collection of users defined by the MCPTT Administrator (e.g., representing a particular organizational structure) and intended to be the recipients of Broadcast Group Calls.
User ID: The main unique identifier for an MCPTT User.
User Regroup: The temporary combining of a multiplicity of users into a new group.
3.2 Abbreviations
For the purposes of the present document, the abbreviations given in TR 21.905 [1] and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905 [1].
FIFO First In First Out
GCSE_LTE Group Communication System Enablers for LTE
KPI Key Performance Indicator
MCPTT Mission Critical Push To Talk
MOS-LQO Mean Opinion Score – Listening Quality Objective
P25 Project 25
PESQ Perceptual Evaluation of Speech Quality
POLQA Perceptual Objective Listening Quality Assessment
ProSe Proximity Services
PTT Push To Talk
RFSS Radio Frequency (RF) Subsystem as defined in the TIA-102 specifications (P25)
TETRA Terrestrial Trunked Radio
TIA Telecommunications Industry Association
UIC Union Internationale des Chemins de Fer