Everything you should know about ORAN-SC Architecture in 30 minutes or less
(at least the minimum to work on testbed)
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LASSE - 5G & IoT Group - Federal University of Pará
ORAN-SC Architecture Overview
Interfaces
Service Management and Orchestration (SMO)
SMO is an automation platform for Open RAN and the specifications for the SMO framework are defined by the Open RAN Alliance.
Interfaces
What is eNB?
It is the hardware that is connected to the mobile phone network that communicates directly wirelessly with mobile handsets (UEs), like a base transceiver station (BTS) in GSM networks.
C
U
D
U
Centralized
Unit
Distributed
Unit
O-CU
O-DU
CU provides support for the higher layers of the protocol stack such as SDAP, PDCP and RRC
DU provides support for the lower layers of the protocol stack such as RLC, MAC and Physical layer.
5G CORE
gNB-CU
gNB-DU
gNB-DU
gNB-DU
NG
NG
Xn
F1
F1
F1
gNB-CU
gNB-DU
gNB-DU
gNB-DU
F1
F1
F1
overview about interfaces of SMO
A1 Interface:
A1 interface is used for policy guidance. SMO provides fine-grained policy guidance such as getting User-Equipment to change frequency, and other data enrichments to RAN functions over the A1 interface.
R1 Interface:
R1 interface operates towards multi-vendor rApps. It is designed to support portability of multi-vendor rApps and provides value-added services to rApp developers and solution providers. The interface enables Open APIs to be integrated in the SMO framework.
overview about interfaces of SMO
O1 Interface:
SMO supports O1 interface for managing the operation and maintenance (OAM) of multi-vendor Open RAN functions including fault, configuration, accounting, performance and security management, software management, and file management capabilities.
O2 Interface:
O2 interface in SMO is used to support cloud infrastructure management and deployment operations with O-Cloud infrastructure that hosts the Open RAN functions in the network. O2 interface supports orchestration of O-Cloud infrastructure resource management
overview about interfaces of SMO
M-plane:
For, SMO supports NETCONF/YANG based Open FrontHaul M-Plane as an alternative to O1 interface to supporting multi-vendor O-RU integrations. Open FrontHaul M-plane supports the management features including startup installation, software management, configuration management, performance management, fault management and file management.
ORAN-SC Again
The nRT RIC manages events and resources that require very fast response times down to 10 milliseconds. It uses closed-loop measurements such as data analytics and input from the non-RT RIC, plus artificial intelligence and machine-learning algorithms “to optimize traffic, to optimize mobility, to optimize load to reduce energy consumption and other improvements across multiple radios.
The non-RT RIC, responds to “less urgent messages” on a timescale of 1 second or more. It operates deeper within the network, from within the Service Management Orchestration or SMO platform. rApps are specialized microservices operating on the nonRT RIC for optimization and automation; the non-RT RIC communicates with the nRT RIC’s xApps to provide policy-based guidance to assist in RAN optimization.
Non-Real TIme Ric
Near-Real TIme Ric
Open Interface
What is O-Cloud?
The O-RAN Alliance defines O-Cloud as a cloud computing platform comprised of a collection of physical infrastructure nodes that meet O-RAN requirements to host the relevant O-RAN functions.An O-Cloud will include functionality to support both deployment-plane and management services.
ORAN-SC Again
overview about interfaces of ORAN-SC
X2 Interface:
The X2 interface is broken up into the X2-c and X2-u interfaces, where the former is for the control plane and the latter is for the user plane. Both are originally designed by 3GPP for sending information between a 4G network’s eNBs, or between an eNB and a 5G network’s en-gNB.
NG Interface:
The NG control and user plane interfaces connect an O-CU control plane (O-CU-CP) and O-CU user plane (O-CU-UP) to the 5G core. The control plane information goes to the 5G access and mobility management function (AMF), which receives connection and session information from the user equipment.
Overview about interfaces of ORAN-SC
E1 Interface:
The last of the 3GPP-based interfaces is the E1 interface. It connects the two disaggregated O-CU user and control planes. It transfers configuration data and capacity information between the two O-CU planes. The configuration data ensures the two planes can interoperate. The capacity information is sent from the user plane to the control plane and includes the status of the user plane.
E2 Interface:
The near real-time RIC in the open RAN architecture connects to the O-CU, O-DU, and O-eNB with the E2 interface. These elements combined make the E2 node. An E2 node can only connect to one near real-time RIC, but one of those RICs can connect to multiple E2 nodes. The protocols that go over the E2 interface are only control plane protocols.
overview about interfaces of ORAN-SC
F1 Interface:
The F1 interface, again broken into control and user plane subtypes, connects the O-CU-CP and O-CU-UP to the O-DU. It exchanges data about the frequency resource sharing and other network statuses. One O-CU can communicate with multiple O-DU via F1 interfaces.
Obrigado!