Page 254 - 5G Basics - Core Network Aspects

1 Core network aspects

1 Scope
As defined in [ITU-T Y.2251], multi-connection functionality provides capabilities to the user equipment and
network to support simultaneous attachment to multiple access technologies. Furthermore, it controls and
coordinates media sessions and components through multiple access technologies.
The user experience depends on the access technologies provided: high throughput, low delay, high security,
etc. Multi-connection enables users to utilize either one of the available access technologies, or to utilize
several at the same time. It is recognized that both operators and users will benefit from the harmonization
of multiple connections, such as efficient utilization of network bandwidth, load balancing, high reliability of
connection and continuity of services.

This Recommendation describes the functional architecture of multi-connection in terms of the overall
functional requirements and the high-level overview of the multi-connection framework itself. The objective
of this Recommendation is to develop the functional architecture, definitions and capabilities of the relative
functional entities, and to describe the relationship between the multi-connection functional architecture
and the NGN functional architecture [ITU-T Y.2012].

2 References
The following ITU-T Recommendations and other references contain provisions which, through reference in
this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated
were valid. All Recommendations and other references are subject to revision; users of this Recommendation
are therefore encouraged to investigate the possibility of applying the most recent edition of the
Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is
regularly published. The reference to a document within this Recommendation does not give it, as a stand-
alone document, the status of a Recommendation.
[ITU-T Y.2012] Recommendation ITU-T Y.2012 (2010), Functional requirements and architecture of
next generation networks.
[ITU-T Y.2251] Recommendation ITU-T Y.2251 (2011), Multi-connection requirements.

3 Definitions

3.1 Terms defined elsewhere

This Recommendation uses the following terms defined elsewhere:
3.1.1 functional entity [ITU-T Y.2012]: An entity that comprises an indivisible set of specific functions.
Functional entities are logical concepts, while groupings of functional entities are used to describe practical,
physical implementations.

3.1.2 mediated services [ITU-T Y.2012]: Services that are based on intermediate service stratum facilities
provided by one or more service providers.

3.1.3 multi-connection [ITU-T Y.2251]: The functionality which provides capability to the user equipment
(UE) and network to maintain more than one access network connection simultaneously.
NOTE 1 – All connections are coordinated to provide service to higher layer entities.
NOTE 2 – In a multi-connection communications at least one UE is required to be a multi-connection UE.
3.1.4 non-mediated services [ITU-T Y.2012]: Services that are not based on intermediate service stratum
facilities provided by any service provider.

3.2 Terms defined in this Recommendation
This Recommendation defines the following term:

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