Page 170 - ITU-T Focus Group IMT-2020 Deliverables

3 ITU-T Focus Group IMT-2020 Deliverables

Resource orchestrator can act as the slice management and orchestration, and it can be realized in
hierarchical way. Authorization between application and network capability exposure platform is needed.
Resource provider can act as the resource management and orchestration, which realizes the deployment of
network slice functions including network connectivity. Transport SDN is an underlying technology of
providing the overall bandwidth guarantee on an instantiated network slice.

8.2 End-to-end slice

8.2.1 Overview
The softwarization of the IMT-2020 wireline network requires that nearly all components of the IMT-2020
network be programmable. Many of the wireline components available today are already programmable
with various API’s and it is expected that these will not be changed substantially but will instead be
augmented to support new applications like 5G. As a result the softwarization process requires that multiple
existing technologies together with the new technologies be blended in a manner that permits convenient
programming of the entire end to end network from a single location. Since SDN is already (or will soon be)
a major component of networks it is expected that SDN controllers/orchestrators of various types will be
responsible for the different network components and that a layer above those SDN
controllers/orchestrators will be required to control and co-ordinate the end to end 5G wireline behaviour.

MASTER
METRO N/W SLICE CONTROLLER C-RAN INSTANCE
CONTROLLER SLICE CONTROLLER
C-RAN INSTANCE D-RAN C-RAN INSTANCE
SLICE CONTROLLER CONTROLLER SLICE CONTROLLER
UE SLICE FH SLICE IDC SLICE CRAN FABRIC CRAN SERVER DC SERVER DC FABRIC IDC SLICE FH SLICE Mm & UE SLICE
CTRL CTRL CTRL CTRL CTRL CTRL CTRL CTRL CTRL uWave CTRL
CTRL
DC
CONTROLLER
Fabric Server
DWD RAT / CN Control Control
M
RAT/ CN RAT / CN
CN / MEC RAT/ CN mmWave
R CN / MEC
A CN/MEC RA
T T
RAT/ CN CN CN CN CN/MEC
CN Idle/off CN CN
RAT/MEC CN CN CN CN CN RAT/ CN
Idle/off Idle/off CN mmWave
DWD RAT/MEC
M DC POD Idle/off
DC POD mmWave
PON IP o <anything> mmWave
D-RAN
Analog RAT

Figure 8.2-1 – Hierarchy of controllers and relationship to wireline orchestration
Figure 8.2-1 gives a likely logical/hierarchical arrangement of controller entities that are required to control
the 5G wireline and in particular to implement slicing at the wireline level. Note that the picture depicts
different controller entities but they may be combined of course. Note also that a controller does not
uniquely imply a direct SDN (OpenFlow) model, indirect (MPLS/GMPLS etc.) distributed control planes with
various flavours of PCE are also possible and even likely.
Based on the above figure, this contribution will start to elaborate the sequences of events that would occur
as a result of various orchestration events. We do not try to detail the formats or APIs but rather what would
happen when a particular orchestration event is requested or triggered. In other words we are discussing the
actors and their general conversations not the exact language used.

First we begin with a list of high level descriptions of the various controller functions (actors involved):

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