Page 475 - 5G Basics - Core Network Aspects

Core network aspects 1

3 Definitions

3.1 Terms defined elsewhere

This Recommendation uses the following terms defined elsewhere:
3.1.1 handover [ITU-T Q.1706].

3.1.2 seamless handover [ITU-T Q.1706].
3.1.3 service continuity [ITU-T Q.1706].

3.2 Terms defined in this Recommendation

NOTE – For convenience, this Recommendation uses the terms "mobility" and "mobile UE" to imply service continuity
at a minimum, with the intent to achieve seamless handover. This is explicitly contrasted with nomadicity, although the
latter is included in the broader definition of [ITU-T Q.1706].
This Recommendation defines the following terms:
3.2.1 access service authorizer: A network operator that authenticates a UE and establishes the UE's
authorization to receive Internet service.

3.2.2 access service provider: The operator of the access network to which the UE is attached.
3.2.3 adaptive QoS resource management: The network capability which may afford dynamic QoS
assurance to mobile UE according to network capability, user preference and service administration policies
during handover. With this capability, the network may dynamically change the QoS resources granted to
the individual flows of a session upward or downward within the range set by the application.
3.2.4 anchor point: A location in the forwarding plane above which movement of the terminal equipment
within a certain topological scope is masked by the provision of mobility service at layer 3. "Above" means
"on the side away from the user equipment (UE)". There may be more than one anchor point on the path
between the UE and a correspondent entity.

3.2.5 anchoring network: The network within which an anchor point resides.
3.2.6 candidate access point (or network): An access point or network being evaluated as a possible new
point of attachment (new serving access network) after handover.
3.2.7 handover latency: A delay in delivery of user data during handover due to the use of buffering as
part of the handover procedure.

3.2.8 handover quality: The degree of impairment experienced by the user during the period of handover.
This can range from cut-off (loss of service continuity) to a degree of impairment unnoticeable by most users.
The latter condition is taken as the working definition of seamless handover.
3.2.9 host-based mobility: A mode of operation whereby the mobile UE takes an active role in the
provision of mobility service at layer 3, in particular by contacting the mobile service provider directly to
invoke this service after gaining network access.
3.2.10 integrated scenario: A scenario in which the same AAA infrastructure is used to authorize both
transport and mobility service, so that a common set of user credentials is used to gain access to both
services.

3.2.11 mobility service authorizer: A network operator that authenticates a UE and establishes the UE's
authorization to receive mobility service. It is assumed in the network-based case that this authorization
covers the affected components both in the anchoring network and in the access network.

3.2.12 mobility service provider: A network operator that provides mobility service. In the case of network-
based mobility, this term refers specifically to the operator of the anchoring network, taking note that the
access service provider is actually the operator of the equipment providing the tunnel lower end.
3.2.13 network-based mobility: A mode of operation whereby the mobile UE does not take an active role
in the provision of mobility service at layer 3.

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