Cloudification of Test Software，Keysight Open RAN Architect (KORA) software is available on AWS

It's no surprise that major software tools are moving to the cloud. As mysterious as the cloud may be to those unfamiliar with modern software hosting architectures, its benefits on paper are clear: lower IT overhead, reduced costs, and scalability. The wireless communications world has been moving radio access network (RAN) software to the cloud for over a decade. Cloud RAN was a popular architecture during the 4G LTE era. With the rise of Open RAN (O-RAN), running RAN software on white-box servers and readily available cloud platforms is increasingly attractive for 5G. Disaggregation of processing means less and less purpose-built hardware is necessary for a RAN architecture. Specifications that tighten timing and latency requirements enable the use of cloud-native RAN software in the design.

The mobile networking demand has increased beyond expectations. 4G has moved from 9 million subscribers to 4.7 billion in the past decade, and mobile networks are carrying almost 300 times as much traffic as they did in 2011, according to the Ericsson Mobility Report. To meet subscriber expectations, especially as more vertical markets look to 5G for connectivity, mobile network operators (MNOs) rely on the cloud to scale up.

The scalability requirements aren't the only reason MNOs are turning to cloud-based RAN solutions. Resource virtualization in the cloud allows for resource optimization that provides flexibility to these modern 5G deployments. MNOs can deploy services at the edge instead of the core, allowing for lower latency and more responsive service for key applications. They can pool resources dynamically. And high-performance data center-type servers allow for computational power that wasn't previously available to existing networks. All these capabilities lend themselves to making the modern wireless network nimbler and more scalable to anticipate the needs of the next generation of technology that wishes to connect across them.

Major carriers and infrastructure vendors have already begun their deployments. Ericsson has been a major supporter of cloud RAN efforts. Rakuten Mobile and Altiostar have launched the first cloud-native, container-based 5G RAN solution. And DISH and Amazon Web Services (AWS) have partnered to form strategic collaborations to reinvent 5G. The move to the cloud is happening, but not without challenges.

Hard Times in Software

Testing becomes increasingly complex with the shift to integrating the cloud into RAN deployments. O-RAN has introduced a heavy emphasis on testing and automation as part of the architecture. The RAN development process is adopting tools and techniques commonly found in the software development world. Continuous integration and continuous development (CI/CD) workflows have become commonplace in large-scale software development efforts. The notion of testing early and often, paired with the frequent iterations of software updates, means that testing is not just happening at the start or end of a project but is a continuous element running alongside the development process.

For network equipment manufacturers and operators, the design and research lab and the operations testing efforts are coalescing. Think of it this way: RAN is moving from a "waterfall" software development methodology, where development teams complete functional pieces of code and pass them downstream to the next team, to an "agile" software development methodology, with collaboration and improvements occurring throughout the development cycle. When this happens, the natural gating of testing that occurs shifts. No longer does particular team conduct testing up to a certain point, then throw it over the wall to the downstream team. Testing becomes on-demand, repeated over and over inside the development process.

You Can Take It with You

With this shift toward more testing, the tools used for testing the RAN in the lab and the field have to scale up and meet the same demands as the RAN software. When your entire software stack starts heading to the cloud, you need test tools that will follow. The software tools that will be the most valuable are those that scale with you and deliver competitive coverage.

The same advantages discussed previously regarding changing the business model for software costs ring true here with test software. Instead of up-front test software purchases or complex, multiseat / multi-region license management, test software that's available and ready for a cloud deployment shifts the cost from Capex to Opex. Test software becomes a service. Like any service, the move to a metered, utility pay-as-you-go model becomes more scalable and easily managed from a cost perspective. The gains go beyond getting the right software at the right price for your business. The tighter coupling of test software in the cloud with RAN software means that the insights gained in the R&D lab can be delivered at the network deployment. Operations teams can better understand how the network operates and access emulated test scenarios on-demand.

The test software is following the movement of commercial RAN software to the cloud, and KEYSIGHT is leading the way. Keysight Open RAN Architect software (KORA)  is available on AWS. KORA provides multiple simulators working in unison to deliver a seamless solution to vendors, carriers, and testers to verify the end-to-end O-RAN ecosystem infrastructure. The test software landscape is changing rapidly, and now is the time to plan your move to the cloud with your test vendor at your side.