---
title: "Open RAN without the futurism: what operators actually test in multi-vendor networks in 2026"
description: "Intelligent RAN Forum 2026: what operators in different countries test in 4G, 5G and Open RAN networks, which emulators they need, how to stay on budget."
---

[TEST4NET Blog — Network & Security Testing Insights](https://test4net.com/blog)

# [Open RAN without the futurism: what operators actually test in multi-vendor networks in 2026](https://test4net.com/blog/open-ran-testing-multi-vendor-networks-2026)

 Written by [Alexander Zemskov](https://test4net.com/blog/author/az) | Oct 23, 2026, 6:00:00 AM

At Intelligent RAN Forum 2026, VIAVI and Battelle talked about AI in the RAN. The most useful number from the event has nothing to do with AI. According to Battelle, the first integration of its radio unit with another vendor's DU took months. Today the same job takes weeks. That is multi-vendor RAN in 2026: integration and regression. An operator's test lab will be doing exactly this for several more years, and AI applications for the RIC will sit on top of that work when their turn comes.

## Where the market actually stands

GSMA forecasts that in Sub-Saharan Africa 4G will become the dominant technology and reach half of all connections only by 2030. 5G there will hold around 17% by the same date, mostly in South Africa, Nigeria and Kenya. GSMA's global forecast for end-2025: 5G at roughly a quarter of connections, 4G at about 55%.

The typical operator today runs 4G plus 5G NSA, sometimes with its first Open RAN sites. Its multi-vendor setup happened by itself: a supplier swap, legacy from earlier procurements, new sites from a different manufacturer. What gets tested is interoperability, and the word "innovation" is rarely heard in that lab.

## What gets tested in practice

The O-RAN Global PlugFest Fall 2025 under the O-RAN ALLIANCE gives an honest picture: 64 companies, 19 labs, 25 operators and OTIC centres as hosts, tests running from August to November 2025. 4 tracks recur both at PlugFests and in operator labs:

- **Open fronthaul.** O-RUs are checked for conformance to WG4 specifications across 4 planes: C, U, S and M.  
  The radio is connected to an O-DU emulator, the DU to an O-RU emulator (at Keysight, Open RAN Studio and RuSIM play these roles).  
  This is how M-plane discrepancies and synchronisation issues are caught before equipment from different vendors is trucked to the same site.
- **End-to-end performance.** A gNB or eNB sits between a subscriber emulator (the Keysight UeSIM class) and a core emulator (CoreSIM).  
  Teams measure throughput, latency and behaviour in stress scenarios: mass registrations, handovers, traffic peaks.  
  For the core there is a separate class of tools (Spirent Landslide, Keysight LoadCore): thousands of emulated UEs and gNBs load the AMF/SMF/UPF without a single real base station.
- **Security under load.** Automated 3GPP SCAS tests, DDoS and fuzzing run in parallel with emulated subscriber traffic. The question is what happens to subscriber QoE while the gNB is fending off the attack.
- **RIC.** Near-RT and non-RT RIC are checked on the A1, E2 and O1 interfaces with emulated E2 nodes. VIAVI's assessment: the RIC has already moved from specifications into production labs.  
  For most operators this is the next stage, but it is cheaper to leave room for it in the lab architecture now.

## Pitfalls

- "Weeks instead of months" applies to the second and later integrations. The first one still takes months.
- VIAVI names frequent software updates as one of the main difficulties of Open RAN. Every DU or RIC release means another round of fronthaul and E2E regression. Without automation, the lab cannot keep up with that pace.
- Battelle points to the absence of common metrics and data formats across vendors. Radio, DU and core logs do not line up directly, and locating the source of a problem stretches into weeks.
- A core emulator does not replace a test against a real core, and a UE emulator does not replace real phones. Emulation answers 80% of the questions for moderate money; the rest is checked on a small pilot.

## Where this is heading

AI in the RAN is already in use, but in narrow spots. VIAVI and NTT Docomo demonstrated AI-driven beamforming management with system throughput gains of up to 20% thanks to lower control overhead. VIAVI offers a RAN scenario generator to train and validate models on synthetic data, since operator data is closed. The main brake today: trust in a system with no human in the loop. The practical takeaway for an operator: start collecting and normalising data now, and schedule AI application testing for the RIC rollout stage.

## What this means for the business

A multi-vendor network saves on procurement and moves the risk to integration. Every supplier software update can turn into an outage for subscribers. A lab with emulators costs money, but less than site visits, rollbacks and complaints. A mid-sized operator does not have to buy the full stack: pick 3–5 critical scenarios, rent time at an OTIC or a partner lab, and automate regression. Then one engineer validates a release in days.

## What to do

- **Record the actual state of your network:** 4G, 5G NSA, first O-RUs, and which inter-vendor interfaces already exist.
- **Pick your scenarios:** fronthaul conformance, E2E load, security under traffic.
- Decide what to emulate and what to verify on real hardware, and cost out each option.
- Automate regression from day one.

Planning a test lab for a multi-vendor network? Contact TEST4NET: we will review your configuration and propose a plan.

## Sources

- [Open RAN testing in the AI era – RCR Wireless, Intelligent RAN Forum 2026](https://rcrwireless.com/20261007/open_ran/open-ran-ai-testing)
- [O-RAN Global PlugFest Fall 2025 results – O-RAN ALLIANCE (via AAP)](https://www.aap.com.au/aapreleases/cision20251211ae44590)
- [Keysight at O-RAN Spring 2023 Global PlugFest – Business Wire](https://www.businesswire.com/news/home/20230629364737/en)
- [RuSIM – O-DU Testing Solution datasheet – Keysight](https://go.keysight.com/us/en/assets/3120-1436/data-sheets/RuSIM-UERU-Emulation-Solutions-Over-the-O-RAN-Fronthaul.pdf)
- [GSMA Mobile Economy Sub-Saharan Africa 2024 – press release GSMA](https://www.gsma.com/newsroom/press-release/powering-progress-through-connectivity-gsmas-mobile-economy-sub-saharan-africa-report-calls-for-action-to-close-the-digital-dividenew-report-highlights-opportunities-in-ai-5g-and-satellite-connectivit/)
- [GSMA: 5G to represent 25% of global mobile connections by end-2025 – RCR Wireless](https://www.rcrwireless.com/20220301/5g/5g-represent-25-global-mobile-connections-end-2025-gsma)

[View full post](https://test4net.com/blog/open-ran-testing-multi-vendor-networks-2026)

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