Interview with Haran Somasegaran, APT Product Leader
Haran Somasegaran is a Product Planner and R&D Manager at Keysight Technologies, based in Aalborg, North Jutland, Denmark. With a career spanning more than six years at Keysight, Haran has been in his current role since January 2019. Haran's expertise encompasses product development, strategic planning, and research and development in the field of electronic measurement technology. Haran stands out with extensive experience with 3GPP standards, particularly in L1-L3(AS) and NAS for GSM, WCDMA, LTE, and 5G NR technologies.
OpenTAP: Why did the APT team choose OpenTAP for the product/toolset?
Haran: In the initial design phase of the APT Toolset (S8708A), our main objective was to empower customers by providing a framework that allowed them to scale their software/hardware automation setups according to their particular needs, without requiring direct support.
A key element of any test and automation solution is the sequencer. Although our R&D team could have easily developed a basic sequencer, scaling it to meet diverse customer requirements—such as various test steps for automating different instruments or software components—and maintaining it, would have been a significant challenge. OpenTAP addressed this problem effectively.
OpenTAP: In particular, how does OpenTAP help the S8708A meet its specifications and mission requirements?
Haran: We chose OpenTAP (and its Keysight commercial version, KS8400 PathWave Test Automation) because it provides a robust and independent test sequencing software platform, making it an ideal fit for our automation solution. OpenTAP/KS8400 enables our R&D engineers, who specialize in specific software/hardware components, to create plugins independently, execute test sequences, and develop their own test steps in C#. Keysight customers can do the same with our solution. This independence has allowed our general software developers and APT R&D team members to focus on our primary goal of developing and releasing solution-level software features.
OpenTAP: What types of customers use the tool set?
Haran: Our customers are R&D and verification teams at network operators, wireless modem manufacturers, and 5G device vendors developing and verifying new prototypes and commercial products.
OpenTAP: Are those customers exposed directly to OpenTAP or only through the APT UI/UX?
Haran: Our customers utilize both the KS8400 UI and the APT UI. The APT UI provides a solution-level overview of test case executions, such as combining the output/input of multiple test sequence executions using OpenTAP. Our customers use KS8400 directly for debugging, modifying, extending existing test cases, and creating new ones.
OpenTAP: What has been your personal experience with OpenTAP?
Haran: OpenTAP and KS8400 enable our developers and test team to prototype new test plans more quickly. I've noticed that customers are delighted to find that the features they request for the sequencer are either already available in OpenTAP or planned in its roadmap.
While using OpenTAP may not offer the same flexibility for quick hacks as an in-house sequencer would, I see this as a benefit. It helps our developers avoid technical debt. Moreover, the OpenTAP community leverages the de facto standard provided by OpenTAP to develop plugins for various instruments. Having a standards-based platform and an ecosystem around it clearly outweighs the tactical benefits of having one's own RYO sequencer. Building on OpenTAP also eliminates the need to maintain yet another piece of code and to sustain expertise around it.
OpenTAP: Have you or the APT team made any contributions to the OpenTAP project?
Haran: APT R&D staffers has occasionally encountered bugs in OpenTAP/KS8400. We don't expect new software releases to be flawless; the issues we've reported have been resolved, allowing us to proceed with APT software releases. We've also made feature requests, most of which had already been submitted by others and were included in the OpenTAP roadmap. We have also created OpenTAP plugins and other resources for UXM5G and PROPSIM as part of APT Toolset solution delivery.
Keysight Advanced Performance Test Toolset
The Keysight S8708A 5G Advanced Performance Test Toolset (APT) enables reliable lab testing of mobile devices. This end-to-end wireless device test solution lets chipset and device makers together with mobile operators evaluate and optimize the performance of 5G devices in a lab environment. The toolset is a part of Keysight’s 5G Network Emulation Solution portfolio that addresses the entire device development workflow from early design to acceptance and manufacturing.
The solution offers a verified test set developed before the release of 3GPP FR2 MIMO OTA. It allows R&D teams to test beam management in a 3D spatial fading channel at millimeter-wave (mmWave) frequencies. It covers advanced performance testing above standard requirements for beam management testing with predefined test cases and customizable test scripts that meet specific customer requirements.
The solution offers:
Verified test set developed before the release of 3GPP FR2 MIMO OTA
Validated channel models for FR2 MIMO OTA according to the TR38.901 test specification
Predefined and customizable beam management performance test cases
Verified device data throughput performance under CDL channel models in FR1 and FR2
State-of-the art logging, visualization, and debugging tools to resolve issues more quickly