.. This work is licensed under a Creative Commons Attribution 4.0
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.. _docs_5G_oof_pci:

:orphan:

OOF-PCI
--------

Description
~~~~~~~~~~~

The 5G OOF-PCI use case is an implementation of a **SON (Self-Organizing Networks)**
algorithm for Physical Cell ID (PCI) optimization and the centralized Automatic Neighbor Relations
(ANR) function (blacklisting a neighbor for handovers) in a 4G/5G network using the ONAP
Optimization Framework (OOF).

The use case is a multi-releases effort initiated in Dublin release.
This use case began with the implementation of PCI optimization in Casablanca.
In Dublin release, the SON-Handler MS was onboarded as a
micro-service in DCAE. Enhancements were made to Policy and SDN-C components.

In Frankfurt release, the following are the main enhancements:

- Introduction of Control Loop Coordination functionality, wherein a second control loop execution is
  denied by Policy component when another control loop is in progress.
- Introduction of adaptive SON, wherein a set of cells whose PCI values are fixed (i.e., cannot be changed
  during PCI optimization) are considered during the PCI optimization.
- In addition, the first step towards O-RAN alignment is being taken with SDN-C (R) being able to receive a DMaaP
  message containing configuration updates (which would be triggered when a neighbor-list-change occurs in the RAN
  and is communicated to ONAP over VES). `Details of this implementation <https://wiki.onap.org/display/DW/CM+Notification+Support+in+ONAP>`_

The end-to-end setup for the use case requires a Config DB which stores the cell related details of the RAN.
This is updated by SDN-C (R), and is accessed by SON-Handler MS and OOF for fetching (e.g., neighbor list, PNF id, etc):

- `The Config DB implementation <https://github.com/onap-oof-pci-poc/sdnc/tree/master/ConfigDB/Dublin>`_
- `Swagger JSON API documentation <https://github.com/onap-oof-pci-poc/sdnc/blob/master/ConfigDB/Dublin/SDNC_ConfigDB_API_v3.0.0.json>`_

As part of this use case work, a RAN Simulator providing a simulated Radio Access Network
(RAN) with a number of netconf servers simulating PNF elements has been implemented. The
functionality of the RAN Simulator includes:

- Generation of neighbor-list-update messages
- Generation of alarms for PCI collision/confusion and
- Generation of handover metrics for different neighbor pairs (for the ANR use case).

All above functionality are enabled using a simple UI.

Please see also `OOF (SON) wiki page <https://wiki.onap.org/display/DW/5G+-+OOF+%28ONAP+Optimization+Framework%29+and+PCI+%28Physical+Cell+ID%29+Optimization>`_.
Additional information are available related to previous releases can be found
in `El Alto & Frankfurt OOF (SON) wiki page <https://wiki.onap.org/display/DW/OOF+%28SON%29+in+R5+El+Alto%2C+OOF+%28SON%29+in+R6+Frankfurt>`_.

How to Use
~~~~~~~~~~

The OOF-PCI use case is implemented in the Rutgers University (Winlab) ONAP Wireless Lab (OWL).
For details, please see
`lab details <https://wiki.onap.org/pages/viewpage.action?pageId=45298557>`_.

This page includes instructions for access to the lab. Setup and testing is done manually up to now.

For all instructions about installing the components, please see:

- `Wiki Installation page <https://wiki.onap.org/display/DW/Demo+setup+steps+for+Frankfurt>`_
- `Son-Handler installation <https://docs.onap.org/projects/onap-dcaegen2/en/frankfurt/sections/services/son-handler/installation.html?highlight=dcaegen2>`_

Test Status and Plans
~~~~~~~~~~~~~~~~~~~~~

OOF was enhanced with handling cells with fixed PCI values during the optimization,
SON-Handler MS was functionally enhanced for adaptive SON functionality, SDN-C (R)
was enhanced to include handling of DMaaP message for config changes in the RAN,
and Policy was also enhanced with Control Loop Co-ordination function.

See `test plans <https://wiki.onap.org/display/DW/Testing>`_ for details.

Known Issues and Resolutions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

(a) It is intended to have the RAN Simulator support sufficient Honeycomb netconf server instances to simulate 2000 cells.
    However, this number may be lower if there are hardware limitations.
(b) For Control Loop Co-ordination, the denial of a second Control Loop based on Target Lock (i.e., when a second Control
    Loop tries to operate on the same target (in this case, a PNF) is successfully tested. The CLC is also applied at Control
    Loop level only. However, some code updates are required in Policy to properly update the Operations History DB entry, and
    to check the existence of active Control Loops by Policy. This will be addressed in Guilin release, and tracked via
    https://jira.onap.org/browse/POLICY-2581 and https://jira.onap.org/browse/POLICY-2583.
(c) For Adaptive SON, the functionality in SON-Handler and OOF is implemented, however the OOF functionality is not
    fully tested (this was anyhow a stretch goal). Further, the DCAE-CL-RSP message is not sent by Policy in Frankfurt release.
    This is tracked via https://jira.onap.org/browse/POLICY-2580 and shall be part of Guilin release.