Second Global O-RAN ALLIANCE Plugfest Demonstrates the Accelerated Readiness of Multi-vendor O-RAN Compliant Network Infrastructure

By Petr Jurcik (Deutsche Telekom), Anil Umesh (NTT DOCOMO), Santram Vashist (Bharti Airtel) and Tracy van Brakle (AT&T).

In summer 2020, the O-RAN ALLIANCE successfully conducted its second worldwide plugfest and proof of concept to demonstrate the functionality as well as the multi-vendor interoperability of O-RAN based network equipment.

At four venues across the globe, in total 55 companies came together to deal with the functional, interoperability and performance challenges of the O-RAN ecosystem. Test scenarios have successfully passed, proving the readiness of O-RAN implementations for commercial rollout.
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Asia

The second O-RAN ALLIANCE plugfest took place at two Asian venues, East Asia and India.

East Asia

The O-RAN plugfest/PoC in East Asia was conducted in various operator and vendor labs in Japan and China. Activities in Japan were hosted by NTT DOCOMO, KDDI and SoftBank Corp., and activities in China were hosted in China OTIC labs. 16 companies participated. One set of scenarios focused on multi-vendor interoperability using O-RAN’s open interfaces, while others also involved RAN virtualization and RAN Intelligent Controllers (RIC).

The test scenarios comprised:

1. Multi-vendor IOT with O-RAN’s Open Fronthaul and Open X2 was demonstrated by NTT DOCOMO, Fujitsu, NEC and Samsung. Multi-vendor RAN demos included 5G NSA services with NR on sub 6GHz and mmWave that are already live on NTT DOCOMO’s commercial network. The testing also included a pre-commercial realization of the Fronthaul Multiplexer (FHM) and NR sub 6GHz inter-band Carrier Aggregation.
2. End-to-end network slicing Proof of Concept with RIC radio resource management was demonstrated by KDDI and Samsung. The resource management feature was realized by O-RAN interfaces with enhancements to enable E2E network slicing use cases.
3. Integration of full containerized virtual RAN and multi-vendor IOT with NEC O-RU and Mavenir O-CU/O-DU using O-RAN Open Fronthaul was introduced by SoftBank Corp.
4. The O-RAN based F1 and E1 interfaces leveraging 5G fully virtualized Control and User plane CU, Open Fronthaul multi-vendor IOT between 100% software RAN, and 3rd party O-RU support, were introduced by JMA Wireless.
5. IOT between O-RU and O-DU emulator using O-RAN Open Fronthaul was demonstrated by Kyocera.
6. Distributed Antenna System and O-RU development was introduced by Toshiba.
7. Multi-vendor 5G small cell with O-RAN Open Fronthaul and ARM based virtualization platform were demonstrated by CIG, Altran, ASTRI, Keysight, NXP and Radisys. Demos included IOT of O-RU and O-DU emulator, and integration of ARM based platform, L1 and L2/L3/5GC software from different vendors.

India

Hosted by Bharti Airtel, the India Plugfest was held at Gurgaon and Bengaluru locations. Demonstrations from 10 companies were put together to showcase O-RAN-compliant Open Fronthaul multi-vendor interworking, O-DU system validation, O-RAN-compliant open X2 interface, and Radio Intelligent Controller (RIC) use cases compliant with O-RAN O1 and E2 interfaces for network performance optimization, combining machine learning and radio intelligence:

1. Altiostar and NEC teamed up to demonstrate interoperability and integration of O-RU and O-DU based on O-RAN Open Fronthaul Specifications comprising of CUSM-plane protocols. 3GPP radio conformance tests as well as performance test cases were executed successfully.
2. VVDN, Xilinx and VIAVI demonstration consisted of VVDN developed Open Fronthaul O-DU implementation on Xilinx’s T1 Telco Accelerator card integrating a third party L1 stack. The VIAVI TM500 O-RU emulator was used for in-depth verification of O-DU OFH implementation. Testing of S-Plane PTP master and CU plane interoperability based on O-RAN OFH specifications were carried out.
3. Mavenir demonstrated coverage and capacity optimization, Mobility Robustness Optimization (CCO & MRO rAPP) and O1 interface compliance testing as per O-RAN standard. Key elements of setup include Non-Real-Time RIC, which makes use of advanced machine learning algorithms using Bayesian optimization to optimize network performance, O-eNB, and EMS supporting O-RAN O1 NETCONF. The closed-loop automation provides a way to continuously monitor and tune the system parameters.
4. STL and ASOCS demonstrated mobile load balancing (MLB xApp) and E2 setup and subscriptions as per O-RAN standard. The key elements of overall setup include Near–Real-Time RIC and MLB xApp developed by STL and O-eNB developed by ASOCS. Automatic MLB use case helps in controlling and managing the radio resources efficiently to enhance user experience.
5. Altran showcased compliance to O-RAN Open X2 specification between MeNB and SgNB. Altran successfully demonstrated ENDC X2 Setup and SgNB Addition procedure.

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Europe

Deutsche Telekom, TIM, Telefónica, Orange, and BT have teamed up together with the Telecom Infra Project (TIP) to host the first Joint O-RAN & TIP plugfest. O-RAN and TIP jointly worked on the definition of test cases and test scenarios, enabling future cooperation and synergy between the Open Testing and Integration Centre (OTIC) and TIP community lab. The plugfest focused primarily on Open Fronthaul interface, associated transport options, and multi-vendor interoperability.

For the first time, network operators across Europe and across the O-RAN ALLIANCE and TIP communities tested the O-RAN solutions together, and shared between them the detailed results, experiences, and lessons learned.  The joint, open, and coordinated effort greatly accelerates the technical evaluation of O-RAN solutions, helps to assess and progress the state of the industry, and effectively avoids duplication of efforts for all involved parties whether network operators or solution providers.

As part of the event, products and solutions from 27 manufacturers were used in three operator labs, namely Berlin hosted by Deutsche Telekom, Torino hosted by TIM, and Madrid hosted by Telefónica. O-RAN Radio Units (O-RU), Distributed, and Central Units (O-DU/O-CU) were installed, integrated and tested on-site at these labs. More than 80 engineers from participating solution providers collaboratively supported the integration and testing, most of them remotely due to Covid-19 travel restrictions.

Test and measurement equipment was provided by Calnex, EXFO, Keysight Technologies, ng4T, Rohde & Schwarz, and VIAVI Solutions.

The O-RU and O-DU/O-CU devices for end-to-end system integration and testing were provided by Altran, Astri, Baicells, Foxconn, JMA Wireless, Mavenir, MTI mobile, QCT, Radisys, Wind River, and WNC.

The O-RU devices for sub-system integration and testing with an O-DU emulator were provided by Benetel, CommScope, Delta, Fujitsu, and Xilinx.

The O-DU devices for sub-system integration and testing with an O-RU emulator were provided by Radisys and Wiwynn.

The transport solutions supporting O-RAN infrastructure were provided by Ciena, Cisco and Juniper Networks.

The integration and testing efforts were coordinated by EANTC as the systems integrator, and supported by engineers from the hosting operators and from highstreet technologies, as lab integrators.

As an outcome of the European Joint O-RAN & TIP plugfest:

• O-RAN specifications are enabling open interfaces for disaggregating RAN, adding flexibility and facilitating multi-vendor interoperability
• O-RAN and TIP are collaborating to accelerate MNO's Open RAN efforts
• O-RAN and TIP are helping to accelerate the commercialization of Open RAN & the diversification of the RAN supply chain

The tested products from the European branch of the plugfest will also be listed in TIP exchange, as a reference to the community for the solution tested.

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North America

The joint O-RAN & O-RAN Software Community (OSC) Plugfest/PoC hosted by AT&T and Verizon took place within the indoor/outdoor city-scale “living labs” established by the Platforms for Advanced Wireless Research (PAWR) initiative:

• COSMOS in the New York City metropolitan area
• POWDER in Salt Lake City, Utah.

O-RAN members contributing to the design, development, deployment, and initial operations of these community labs over the past 12+ months include AirSpan, Altiostar, AT&T, Cisco, CommScope, Ericsson, Fujitsu, Juniper, NEC, Nokia, Samsung, Verizon, and Viavi (a partial list).  The investment of time and effort made it possible for the North American Plugfest/PoC to proceed regardless of the Covid-19 pandemic, as participants were able to establish secure connections from their private lab spaces to COSMOS or POWDER and then execute test cases or conduct experiments remotely, safely, and cost-effectively with the support of the community.

The primary focus this year, building upon the results obtained during the first O-RAN Plugfest/PoC in 2019, was to demonstrate the evolution of key O-RAN specifications in conjunction with the enhancements and new capabilities being delivered by Release 2 “Bronze” from the O-RAN Software Community.  Note that the specifications and the software are being worked in parallel, and the software is considered pre-specification:

• Configuration & Persistency Service (C&PS) and its relationship with O1 interface, presented by Nokia and Ericsson with ODL and ONAP components imported from Linux Foundation Networking (LFN)
• A1 interface with OSC components (A1 Adapter & Policy Management Service), demonstrated by Ericsson
• O-RAN Information Model and Data Models (IM/DM) within OSC and aligned with 3GPP, i.e., published models (available for implementation) and recent contributions (experimental) from Accelleran, AT&T, Cisco, Ericsson, highstreet technologies, Mavenir, Nokia, and VMware
• O1/Open Fronthaul and SMO with O-RAN early adopters, e.g., Kumu Networks
• Integration of novel xApps in Near-Real-Time RIC deployed using Akraino REC and AirFrame openEdge infrastructure, demonstrated by Nokia and AT&T
• Bulk Performance Management (O1/OAM, SMO) with IPv4/IPv6, demonstrated by Nokia
• Non-Real-Time RIC with performance and configuration feeds from live network to optimize key performance indicators, demonstrated by Mavenir
• Software upgrade over O1 interface, demonstrated by Ericsson
• Performance Management counter collection over O1 interface, demonstrated by Ericsson
• LNF (ONAP R7) 5G & PNF use cases aligned with O-RAN and 3GPP, presented by Nokia

The next steps within the North American region will include increased coordination and collaboration with other regions across the globe as part of the upcoming O-RAN/OSC Release 3 “Cherry” Proof of Concept scheduled to take place in 1Q 2021.