Subsequent O-RAN releases will extend the MVP with additional features and functionalities based on continuing surveys and updates of the operators’ deployment priorities.
Another 18 newly released specifications bring updates to existing O-RAN standards, enriching them with new functions or updated features according to the O-RAN Architecture.
Below is a brief overview of the newly published documents.
The O-RAN Architecture Description document specifies the overall architecture of O-RAN. It describes all of the O-RAN functions and relevant interfaces that connect these functions. This version introduces the functional architecture of Non-Real-Time Radio Intelligent Controller (Non-RT RIC) with a brief description of rApps, R1 interface, and Non-RT RIC Framework. Other enhancements include implementation options of Fronthaul Multiplexer (FHM) function and Fronthaul Gateway (FHGW) function; definition of Managed Application (MA); and addition of ‘legends’ in the architecture figures.
This specification defines O-RAN OAM interface functions and protocols for the O-RAN O1 interface, which is the management interface between Service Management and Orchestration (SMO) and O-RAN Managed Elements. Version 4 of this document introduces Trace Management for both file based and streaming trace and provides an informative annex on the use of stndDefined VES events. More detail is provided on the supported format for restful notifications with updates in applicable existing services. Additional updates in this version include Heartbeat Management Service, CM services in the area of Subscription Control, Provisioning and CM notifications, fault supervision to identify required notifications, and Performance Assurance with streaming Performance Measurement.
The O-RAN OAM Architecture identifies management services, managed elements, functions and applications supported in O-RAN, including the interworking between SMO and O-RAN O-Cloud management components. Requirements are derived from end-to-end OAM use cases, including the initial provisioning of O-RAN service across VNFs and PNFs and the collection of measurement data. This version identifies the interfaces between SMO and Managed Elements for different models and deployment options. It also provides a framework for lifecycle management of applications delivered from a Solution Provider to a Service Provider/Network Operator.
This document describes potential O-RAN use cases at a very high level, emphasizing how the use case is enabled by the O-RAN architecture along with basic input data and actions required. This version includes 4 new use cases: SU-MU MIMO TM Optimization, Signaling Storm Protection, Cell Congestion Prediction, and L2 IIoT Optimization.
This document describes selected O-RAN use cases in further details to facilitate relevant O-RAN Work Groups to define requirements for associated O-RAN functions and interfaces. This version includes 2 new use cases: DSS, Long Term NSSI Optimization.
This document describes at a high level the O-RAN slicing related use cases, requirements and a reference slicing architecture, and slicing related impact to O-RAN functions and interfaces. This version includes requirements update to capture use case impacts, additional requirements for Multi-vendor slices use case, and addition of ONAP deployment options in the Annex section.
The O-RAN Information Model and Data Models document specifies the Information Model and the Data Models that are foundational for O-RAN’s model-driven architecture and for the functions carried out over O-RAN interfaces. This document includes information about existing standards and industry work referenced in O-RAN, e.g., a prosumer relationship between O-RAN and 3GPP. It also describes the evolving methods and procedures with respect to a modeling continuum that aims to establish one common and coherent Information Model for 5G/LTE RAN from which Data Models may be generated either manually or automated with a set of tools.
The purpose of the use cases is to help identify requirements for Non-RT RIC and A1 interface, eventually leading to formal drafting of interface specifications. For each use case, the document describes the motivation, resources, steps involved and data requirements, followed by the Non-RT RIC and A1 requirements section detailing the functional and non-functional requirements derived from these use cases. This version p updates to Traffic Steering use case with multi-access network scenario enhancements.
Non-RT RIC functional architecture technical report offers the rApp definition, the Non-Real Time (RT) Radio Intelligent controller (RIC) Framework functions and the R1 interface. The external interfaces are also described. The requirements on the Non-RT RIC framework and rApp are collected for the future specification of the Non-RT RIC functional architecture.
The A1 General Aspects and Principles have been enhanced with the definition of the lifecycle management of A1 Enrichment Information (A1-EI). It includes details on the lifecycle of EI Types, EI jobs, and EI Results. These principles are further defined in the A1 Application Protocol.
The A1 Application Protocol has been enhanced to introduce the service descriptions and data models to support the Non-RT RIC delivering Enrichment Information to the Near-RT RIC over the A1 interface. Several enhancements to the A1 Policy (A1-P) aspects have been added, and the versioning and compatibility aspects of the A1 interface and services have been defined.
This document describes the internal architecture of O-RAN Near-RT RIC from a functional perspective，including the general principles, requirements, basic functions and Near-RT RIC API. This version introduces updated requirements, a new platform function "API management services", and minor enhancements on xApp life-cycle management and O1 termination.
Version 5.0 of the specificaitons delivers enhanced C-Plane/U-Plane to increase fronthaul efficiency:
Clarification on PRACH C/U-plane window timing reference and Section Type 3 usage.
Added selective transmission/reception using beam ID for a shared cell in O-RAN.
Added Cascade-FHM mode for shared cell scenario.
Multiple updates to clarify existing material, including:
Renamed NMS to SMO.
In this specification and associated YANG models, following features are added on top of the previous version:
Version 5.0 also provides multiple updates to clarify existing material, including:
Version 3.0 of the document delivers several enhancements over the previous versions, such as:
Version 2.0 of the document delivers several enhancements over the previous versions, such as:
This document describes the Transport Management Plane for the Cooperative Transport Interface (CTI), which specifically provides cooperation between the O-DU and the resource allocation based transport network to reduce the upstream transport latency due to the allocation process. CTI consists of a Transport Control plane (TC) and a Transport Management Plane (TM). This document specifies the TM-plane. Its goals are to define the CTI-related configurable parameters at Transport Node (TN) and at O-DU, to define a suitable set of YANG modules to capture these parameters, to describe necessary steps in the configuration of the parameters, and to define an auto-discovery method to automate the correlation between TN specific parameters and CTI parameters.
The scope of this document is to specify the interface that links O-DU to the SMO. It includes:
Future versions will include adding support for SA deployments, updating YANG models and configuration parameters accordingly, and adding Trace support and Antenna Line Device (ALD) support.
This first version of the Acceleration Abstraction Layer (AAL) General Aspects and Principles introduces the hardware accelerator interface functions and protocols for the O-RAN AAL interface. The document studies the functions conveyed over the interface, including configuration and management functions, and identifies the requirements as well as general procedures and operations. It also introduces the initial set of the O-DU/O-CU AAL profiles.
This is an update of the O-Cloud Reference Designs document to encompass both deployment scenario B and scenario C. Another update concerns the Time Sync for LLS-C3 configuration with detailed requirements and an example design for the cloud platform to support the LLS-C3 configuration.
This is an update of the Orchestration Use-Cases document to include more use-cases, specifically adding the Scale Out/In of Network Function, the Software Upgrade, and the xApp Deployment use-cases.
The document specifies a high-level architecture and hardware design for an Indoor Pico Cell using the Split Option 6 deployment scenario as specified in the Deployment Scenarios and Base Station Classes document.
The O-RAN Base Station O-CU and O-DU Architecture and APIs specification provides the reference architecture, design and APIs for O-CU and O-DU implementation. The specification details the functional block of O-CU and O-DU, including messages across L1, L2 and L3 layers and call flows. This version includes the timing sync aspects of L1, additions and corrections to L2 and L3 APIs, description of O1 and E2 interfaces, and new call flows.
The O-RAN WG8 Stack Interoperability Test Specification provides interoperability test cases of O-CU and O-DU for end to end call flows. It includes the details of test setup, test profiles, and basic interoperability test cases.
This document is intended to describe best practices for O-RAN fronthaul transport based on the Wavelength Division Multiplexing (WDM) technology. It is recognized that other solutions, not based on WDM technology, could be employed or mixed with a WDM solution. Beyond the technologies in this document, other WDM solutions may be adequate for fronthaul transport network and can be considered for future versions of this document.
This document defines the requirements for an Open Xhaul transport infrastructure. As far as possible it tries to make no assumptions about the underlying transport technology, rather define a set of requirements about the overall capabilities of an Open Xhaul transport infrastructure that can support different 5G services, different radio architectures and is multi-service in nature. This document refers to 5G services, but the transport requirements also apply to O-RAN networks deploying 4G services.
The document is intended to describe best practices for O-RAN transport based on end-to-end packet switching technology. It is recognized that other solutions, not based on packet switching, could be employed or mixed with a packet switching solution. Beyond the solutions described in this document, other packet switching solutions may be adequate for Xhaul transport networks and can be considered in future versions of this document.
The present document describes the essential criteria and guidelines (guiding principles) from process, organization, space and technical perspective on the qualified Open Testing and Integration Centre (OTIC). Comparing to version 1.0, the details of OTIC qualification process have been added to Chapter 4, and OTIC application form has been added to Annex A.
Co-chair of the O-RAN ALLIANCE’s Technical Steering Committee,
Member of O-RAN Executive Committee,
Chief Scientist of China Mobile.
Chih-Lin I has been a distinguished expert with nearly 40 years of rich experience in wireless communications. She is a key proponent of ICDT convergence for future wireless networks. She proposed 5G being “Green and Soft” from the first day of 5G design. The philosophy continuously evolved and embraced “Open and Smart” later on, which laid out the foundation for O-RAN.
Co-chair of the O-RAN ALLIANCE’s Technical Steering Committee,
Professor of EE & CS at Stanford University.
Sachin Katti is also Co-Founder and ex-CEO of Uhana (now part of VMware), as well as previously co-founder of Kumu Networks, which is commercializing breakthrough research from his lab on full duplex radios. He received his PhD in EECS from MIT in 2009. His research has won numerous awards, including the 2008 ACM Doctoral Dissertation Award - Honorable Mention, the George Sprowls Award for Best Doctoral Dissertation in EECS at MIT, the IEEE William Bennett Prize, and the Best Student Paper Award at ACM SIGCOMM 2012.
