Release Notes

This document provides the release notes for the Amber Release of the Admission Control xAPP.

Version history

Date Ver. Author Comment
2019-11-04 1.0.0 Ashwin Sridharan First draft


The Amber release of the AC xAPP supports full closed loop control as well as report mode operation for admission control of SgNB Addition requests, reporting of metrics over VES, and configuration of single instance policies via the A1-Interface.

Release Data

Project RAN Intelligent Controller
Repo/commit-ID ric-app/admin
Release designation Amber
Release date 2019-11-14
Purpose of the delivery open-source xAPP for admission control.


  • src/ contains the main source code. Under that directory :
    • xapp_utils.hpp, is generic multi-threaded framework for receiving and sending RMR events.
    • E2AP-c/subscription/ contains generic classes to send/process ASN1 subscription requests, responses, deletes and failures as well as thread-safe subscription handler for managing the subscription process.
    • E2AP-c/ contains generic classes for generating/processing ASN1 E2AP Indication and Control messages.
    • E2SM/ contains generic classes for handling generating/processing ASN1 E2SM service model (e.g event trigger etc).
    • curl/ contains a simple libcurl based class for POSTing JSON messages.
    • json/ contains a generic class for simple JSON key retrieval and modification (based on rapidjson)
    • protector-plugin/ contains code specific to the admission control algorithm and interfaces for setting/getting policy.
  • test/ contains unit tests showing how to use various components as well as mock-ups for integration testing.
  • schemas/ contains the JSON schemas for A1 policy, VES metrics as well as sample payloads.


  • While the xAPP framework used in the AC xAPP supports multi-threading, the admission plugin currently only supports a single thread.
  • The admission plugin supports only a single class of service in current release.
  • The subscription request parameters (RAN Function ID etc) cannot be changed.