Page 124 - ITU-T Focus Group IMT-2020 Deliverables

3 ITU-T Focus Group IMT-2020 Deliverables

Slice controller/
Manager Network Constructed of
Manages
Slice

Composed of Orchestrated Of

Network Utilizes Network
Resource Service

Figure 6.3.4-1 – Basic Network Slice Model

A network slice provides a number of services with dedicated/shared, or physical/virtualized network
resources, and implements network functions to control/manage these services and resources. Different
slices may provide the same types of services with different QoS. A slice controller/mgr manages the virtual
resources and orchestrates them for the user’s service requests. A user/application uses services in one slice
(likely more than one slice), different services can also share a slice if policy permits it. The service of the
upper level slice is an orchestration of the services provided by the lower level sub-slices (intra-domain or
inter-domain).

Each network slice can have a set of physical/virtual resources and functions. Vertically, the resources of the
upper level slice are composed by the lower level sub-slices grouped in different context (e.g., domains,
dependencies, ownerships, share-ability, etc.). The lowest level of resources of the network is constructed
by physical resources. A two-level network slice architecture example is illustrated in Figure 6.3.4-2.

Slice controller/
Network Manager
Slice

Network Network
Resource Service

Orchestrated of
Composed of

Sub-slice Sub-slice Sub-slice Sub-slice
Network controller/ Manager Network controller/ Manager Network controller/ Manager
Slice Slice Slice

Network Network Network Network Network Network
Resource Service Resource Service Resource Service

Figure 6.3.4-2 – Two-tier Network slicing example

The network slicing architecture model depicted in this section is aligned with 3GPP’s three layer slicing
architecture (shown in Figure 6.3.4-3) [3GPP TR 23.799 v0.4.0, 2016-04].

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