For the purposes of the present document, the terms and definitions given in TR 21.905
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
3GPP SSO Authentication:
Authentication performed between an SSO-capable UE and 3GPP SSO Identity Provider using Operator-controlled credentials and without requiring user involvement.
3GPP SSO Identity Provider:
An entity that maintains Operator-controlled identity and credential information for a user, performs 3GPP SSO Authentication, and asserts the user's identity to a Data Application Provider.
3rd Party SSO Identity Provider:
An entity that maintains identity and credential information (that is not Operator-controlled) for a user, performs authentication, and asserts the user's identity to a Data Application Provider.
Attended Data Traffic:
Data traffic of which the user is aware he/she initiated, e.g. based on the screen/keypad lock being deactivated, length of time since the UE last received any input from the user, known type of application (e.g. an application monitoring a user's health - "mHealth" - which may need its data always treated as Attended Data Traffic.)
A manually or automatically initiated emergency call (TS12 or IMS emergency call), from a vehicle, supplemented with a minimum set of emergency related data (MSD).
Data Application Provider:
An entity that offers data application services to users (e.g., over the public Internet). The data applications can be browser or non-browser based services.
The sharing of E-UTRAN among a number of operators.
Free-to-air (FTA) TV:
A TV service characterised by no content encryption and being made available at no additional cost to the end user.
Free-to-view (FTV) TV:
A TV service characterised by optional content encryption and being made available at no additional cost to the end user.
a UE, which acts as a gateway providing access to and from the 3GPP network for one or more non-3GPP devices that are connected to the gateway UE.
GERAN or UTRAN Sharing:
The sharing of GERAN or UTRAN among a number of operators.
Hosting E-UTRAN Operator:
The Operator that has operational control of a Shared E-UTRAN. With regard to management of the Shared E-UTRAN the Hosting E-UTRAN Operator is a Master Operator 
The Shared RAN that is owned or controlled by the Hosting RAN Operator.
Hosting RAN Operator:
The Operator that has operational control of a Shared E-UTRAN, UTRAN or GERAN
IMS Centralized Services:
The provision of communication services wherein services and service control are based on IMS mechanisms and enablers, and support is provided for a diversity of access networks (including CS domain and IP based, wireless and wireline), and for service continuity between access networks.
The Minimum Set of Data 
forming the data component of an eCall sent from a vehicle to a Public Safety Answering Point or other designated emergency call centre. The MSD has a maximum size of 140 bytes and includes, for example, vehicle identity, location information and time-stamp.
A radio access network connecting to the 5G core network which uses NR, E-UTRA, or both.
Authorized operator that is sharing E-UTRAN, UTRAN or GERAN resources provided by a Hosting RAN Operator
RAN user plane congestion:
The situation where the demand for RAN resources to transfer user data exceeds the available RAN capacity to deliver the user data for a significant period of time in the order of few seconds or longer.
The network infrastructure connecting to 3GPP network over the SGi or Gi reference point that provides various IP-based services (e.g. NAT, antimalware, parental control, DDoS protection, video optimization).
E-UTRAN that is shared among a number of operators.
GERAN, UTRAN or E-UTRAN that is shared among a number of operators.
Shared GERAN or UTRAN:
GERAN or UTRAN that is shared among a number of operators.
An entity that provides SSO Service. The SSO Provider enables a user to authenticate to an IdP and thereby to have their identity asserted to a DAP. Each data application, whether provided by different DAPs or the same DAP, may have its own policy regarding authentication. In the 3GPP SSO Service, the SSO Provider is the 3GPP Operator.
A service in which the user of a data application is authenticated once, and as a result of that authentication is provided with seamless and transparent access to multiple data applications offered by one or more Data Application Providers.
SSO Local User Authentication:
Authentication performed by the UE that establishes the presence of the registered user of the data application by requiring input which only the registered user would be able to provide.
Subscribed TV service:
A TV service which is characterised by requiring a subscription (to content owner, content provider, or MNO) in order to access the service.
Unattended Data Traffic:
Data traffic of which the user is unaware he/she initiated, e.g. based on the screen/keypad lock being activated, length of time since the UE last received any input from the user, known type of app (e.g. an application monitoring a user's health - "mHealth" - may need its data never treated as Unattended Data Traffic.)
Additional examples for a user in the context of this TS:
As defined in TR 21.905
: An entity, not part of the 3GPP System, which uses 3GPP System services. Example: a person using a 3GPP System mobile station as a portable telephone.
a non-3GPP device connected to the 3GPP system via a gateway, or an application running on a UE.
information representing a user in a specific context. A user can have several user identities, e.g. a User Identity in the context of his profession, or a private User Identity for some aspects of private life.
a piece of information used to identify one specific User Identity in one or more systems.
User Identity Profile:
A collection of information associated with the User Identities of a user.
An ME with multiple USIMs.
Further definitions are given in TR 21.905