Page 10 - ITU-T Focus Group IMT-2020 Deliverables

1 ITU-T Focus Group IMT-2020 Deliverables

NOTE – A set of managed run-time network functions, and resources to run these network functions, forming
a complete instantiated logical network to meet certain network characteristics required by the service
instance(s). It provides the network characteristics which are required by a service instance. A network slice
instance may also be shared across multiple service instances provided by the network operator. The network
slice instance may be composed by none, one or more sub-network instances, which may be shared by
another network slice instance.
Service Instance: An instance of an end-user service or a business service that is realized within or by a
network slice. Each service is represented by a service instance. Services and service instances would be
provided by the network operator or by third parties.

2.2 Terms and definitions need further harmonization
The following terms need more work to reach consensus in the future ITU-T SG13 meeting.

Network slice: A Network slice is a managed group of infrastructure resources, network functions and
services. Network slice is programmable and has the ability to expose its capabilities. The behaviour of the
network slice realized via network slice instance(s).
NOTE 1 – Network slice enables the operator to create networks customized to provide flexible solutions for
different market scenarios, which have diverse requirements, with respect to the functionality, performance
and resource separation.

NOTE 2 – Infrastructure resources include any kind of resources (e.g., physical, logical, virtual resource).
Orchestration: An automated arrangement, coordination of complex network systems and functions
including middleware for both physical and virtual infrastructures. It is often discussed as having an inherent
intelligence or even implicitly autonomic control. Orchestration results in automation with control network
systems.
Physical resource: A physical asset for computation, storage and transport (e.g. switch, router, antenna, etc.).

NOTE – Network functions are not regarded as resources.
Slice: As a concept describing system behaviour, slice is a logically isolated set of programmable
infrastructure resources (i.e., physical and/or logical resources) to enable functions and services of IMT-2020
network. Slice is created and deleted by order from the orchestrator.

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