For most of the mobile industry’s history, operators bought their radio access networks as single-vendor bundles. One supplier provided the radios, the baseband, and the software, and the pieces were guaranteed to work together because they came from the same company. The arrangement was reliable, but it limited competition and left operators dependent on their suppliers.

Open RAN, short for Open Radio Access Network, was meant to break that model. By defining open interfaces between the radio unit (RU), distributed unit (DU), and centralized unit (CU), it lets operators mix equipment from different vendors. The appeal is straightforward: more suppliers, more competition, and less lock-in. The difficulty is making those mixed components work together reliably once they are carrying live traffic.

Where multi-vendor networks break down

Open interfaces are only as useful as the consistency with which vendors implement them. In practice, suppliers interpret the same specifications differently, test on different schedules, and release software on their own timelines. A small mismatch between an RU from one company and a DU from another can surface as added latency, reduced throughput, or a security gap once the network is in service. Those are the points where deployments stall.

The O-RAN Alliance, the industry body that maintains the specifications, continues to issue technical updates as operators and vendors work through these gaps. Much of the verification still happens in isolation, with different companies independently discovering the same faults rather than resolving them through shared testing. Industry analysts increasingly point to interoperability validation as one of the practical bottlenecks slowing large-scale commercial deployment.

Published research on multi-vendor environments treats the recurring problems, latency, scalability, and security, as structural rather than isolated errors, and argues that interoperability is better understood as a question of governance and system behavior than of standards compliance alone.

“Interoperability is not a feature you can add at the end,” said Sachin Singh, a senior manager at EchoStar with more than two decades in wireless telecommunications. “It has to be built into how you plan, test, and govern the network from the beginning.”

Testing moves from the lab to live networks

One response to the problem has been the creation of integration labs where vendors can validate equipment before it reaches production. EchoStar’s Open RAN Center for Integration and Deployment (ORCID), supported by a $50 million award from the U.S. Department of Commerce’s National Telecommunications and Information Administration, lets approved participants test RU, DU, and CU components against a commercial-grade Open RAN 5G network operated by its DISH Wireless subsidiary.

According to the lab, automating its CU, DU, and security test cases, more than 400 in total, shortened vendor onboarding and sped up fault localization. Singh, who directed the testing and validation strategy there, describes the objective as narrowing the distance between what a lab can verify and how equipment behaves in the field.

Efforts like this sit alongside the O-RAN Alliance’s own plugfests and a growing set of open testing and certification programs. All are pointed at the same goal: giving operators confidence that a given combination of hardware and software will behave predictably before it goes live.

The direction of the research

Newer work is moving past static, checklist-style validation toward context-aware behavioral modeling, where systems are judged by how they actually perform together under changing conditions rather than by whether they pass a fixed set of tests. Research accepted at IEEE WCNC 2025 in Milan proposes frameworks intended to reduce the time and cost of onboarding new vendors into disaggregated networks, and a pending U.S. patent application describes a portal-based approach to component testing and validation.

The common thread is that interoperability cannot be certified once and left alone. As networks evolve, so does the behavior of the parts inside them.

The path forward

Open RAN is no longer a purely theoretical alternative. Certification programs are maturing, operator coalitions are forming, and federally backed initiatives in the United States are funding deployment models meant to hold up under real-world conditions rather than in demonstrations alone.

The open question is whether the industry can close the gap between what it proves in a lab and what operators can build in the field.

“That gap is still too wide,” Singh said. “That is where the real work is.”