Page 57 - ITU-T Focus Group IMT-2020 Deliverables

ITU-T Focus Group IMT-2020 Deliverables 2

• 5G Control Plane

The 5G Control Plane (5G-CP) provides programmable means to control the behaviour of 5G resources (such
as data transport and processing), following requests received from the 5G-ASP and according to 5G-MP
policies. 5G-CP is operating on resources provided by the 5G Resource Layer and exposes an abstracted view
of the 5G access and core network to the 5G Application and Service Plane. The 5G-CP interacts with the 5G
Resource Plane (5G-RP), 5G-ASP, and 5G-MP via standard interfaces.

– Applications and Services Support
The Control Plane Applications and Services Support (CP-AAS) provides a standard interface to the 5G-ASP
for accessing 5G network information and requesting application-specific 5G network behaviours. The
information exposed to 5G-ASP is abstracted by means of information and data models. In case of network
virtualization by softwarization capability, the CP-AAS may expose a subset of network resources which can
be used for exclusive for the virtual network.
– Management Support, Softwarization, and Orchestration
The Control Plane Management Support, Softwarization, and Orchestration (CP-MSSO) provides
management support, softwarization, and orchestration capabilities of 5G-CP and the management, if
delegated by 5G-MP, of network resources based on the policies provided by 5G-MP in multi-domain and/or
heterogeneous 5G access and core network environment. It also provides the capabilities for provisioning CP
functions and managing a particular CP function and its scalability and performance based on the KPIs. It
keeps track of the overall state of allocated and available resources in the 5G-CP.
It orchestrates CP functions based on service policies (e.g., a placement rule which aims to avoid single points
of failure) and softwarizes some CP functions as virtual functions if required.
The CP-MSSO also provides capabilities for connecting multiple 5G access and core network domains in order
to make inter-domain operations. In such case it is responsible for establishing the communication path(s)
required, and for passing appropriate identity and credentials with requests made among these domains.
– Control Plane Functions
The Control Plane Functions (CP-F) provides a set of programmable control and optionally management
functions (if delegated by 5G-MP) covering e.g., discovery of physical and virtual network topologies, network
element configuration, and traffic flows forwarding management, on-demand path computation, monitoring
of responsible resources, mobility management, mobile edge including distributed EPC control, cloud control,
etc.
– Resource Abstraction

The Control Plane Resource Abstraction (CP-RA) provides capabilities to support unified programmability of
resources. Common information and data models of underlying resources are provided so that the
developers of CP functions can simplify their program logics without the need for a detailed knowledge of
the underlying network resource technologies. These models provide a detailed, abstracted view of both,
physical or virtualized network resources. The Resource Abstraction can create multiple virtual resources by
using a single physical resource or can create a composite virtual resource as an aggregation of several virtual
or physical resources. In cases when the Resource Plane provides itself the abstracted view of its resources
to the 5G-CP, the CP-RA can be ignored.

• 5G Resource Plane
The 5G Resource Plane (5G-RP) is where the physical or virtual network elements perform transport and/or
processing of data packets according to 5G-CP decisions. Such data processing can be hardwired as it is the
case at the present or programmable which is supported by user plane deep programmability capabilities.
These decisions, the information about network resources, and resource management policies/requests are
exchanged via standard interfaces.

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