Field-to-lab testing assures high-quality communications in challenging environments

Story

September 13, 2022

In civilian venues, dropped connections and garbled transmissions can be a source of frustration. On military smart bases, they can mean the difference between mission success or failure. No surprise then, that the U.S. Department of Defense (DoD) expects field-communications infrastructures to support clear audio transmission, high-performance video, and nonstop uncorrupted data communications. For those tasked with standing up these environments, however, meeting those expectations can be enormously difficult.

Smart bases, especially those in forward operating environments, present a long list of on-the-ground challenges to reliable, high-performance communications. As these locations often have no existing fiber infrastructure, wireless communications – increasingly, 5G – becomes the default option. However, smart base environments tend to have highly contested and congested airspaces. These venues are also typically characterized by significant noise, fast-moving vehicles and aircraft, interference from geographical topography, and other factors that compromise reliability and quality.

This mix of challenges makes testing of core technologies such as 5G fixed wireless access (FWA), spectrum sharing, and voice/video/data applications critical. Yet, those seeking to conduct realistic testing face a basic dilemma: The environment in which these technologies operate while a smart base is being stood up can be radically different from the conditions that will prevail once it is fully commissioned and operating at scale. Historically, field engineers have had few on-the-ground tools available to bridge this gap. Today, a new generation of “field-to-lab” testing techniques can enable more accurate, predictive evaluations.

Inside field-to-lab performance evaluation

Field-to-lab evaluation draws on the stability and flexibility of lab testing 5G networks and technologies, but uses live feedback from the field environment to enable more accurate results. In this model, data is captured from the real-world smart base environment and imported to a lab testbed, where data logs are replayed to identify potential issues. Deployment teams then adjust the communications network and technologies and repeat the process iteratively. In this way, performance tests draw on the most accurate environmental data, while bringing to bear the full capabilities of a laboratory testbed to simulate the production environment at scale.

By combining the best aspects of field and lab testing, military stakeholders can:

1. Establish a baseline for current performance to identify potential issues
2. Enable repeatability by iteratively testing for multiple factors against that baseline, in ways that are not possible with field testing alone
3. Improve accuracy by creating a lab-testing regime tuned specifically to the target environment
4. Test against field conditions not currently present by adding noise, congestion, movement, and other factors to baseline data
5. Improve relevance and utility of testing by combining live capture of field data with 3D visualizations and creating practical resources to guide optimizations

Testing in action

Once a field-to-lab evaluation framework is in place, stakeholders can proactively test a broad range of smart base communications applications and infrastructure.

• 5G FWA: 5G FWA is among the most effective ways to enable high-performance connectivity in the field. However, as the technology relies on a user’s line of sight, it can be among the most vulnerable to interference and signal degradation. Understanding exactly how the infrastructure will behave in its specific field environment is crucial to identifying issues, correcting them (such as by adjusting antenna placement), and measuring the effects of those corrections. This is also an area where running “what-if” scenarios modeled on potential future conditions can be beneficial. If the infrastructure interfaces with high-speed aircraft, for example, lab testing can emulate Doppler-effect influence on communications long before the network goes into production.
• Dynamic spectrum-sharing (DSS): In urban and congested environments where the commercial market shares spectrum with military applications, spectral interference in shared frequency bands can create significant issues. Historically, however, it has been extremely difficult to evaluate the impact of DSS on military communications via field testing, especially in forward operating environments. A field-to-lab approach makes it possible to run real-world field data through a variety of DSS scenarios, with and without additional impairments, and identify needed adjustments before DSS is implemented.
• Data, video, and voice quality: Traditional field testing can offer an accurate picture of how high-volume military communications perform in a given environment under the calm, relatively noise-free conditions that prevail when that environment is first created. It cannot, however, simulate the thousands of troops, vehicles, and constant motion that exist when a forward smart base is operating at full capacity – even though it is under those conditions that reliable communications are most essential. Field-to-lab testing can take real-world environmental data and test voice, video, and data communications against noisy, highly congested future conditions. Lab test beds can capture drive, flight, and walk testing, including measuring the impact of signal reflection and topographical interference. They can also augment baseline data to simulate motion of vehicles and aircraft at different speeds and vectors, and even the presence of thousands of troops. This sort of testing regimen can proactively reveal drops or degradations and help ensure clear, secure communications in congested environments.
• Speech intelligibility: Nowhere is clear verbal communication more essential than in forward operating environments, especially in scenarios when troops are under attack. Yet measuring audio performance under normal conditions cannot replicate the chaotic scenario of a live environment congested with vehicles, aircraft, and troops. Ensuring that individual words and phrases can be understood, even in noisy and contested environments, is essential – yet extremely difficult to achieve with traditional field approaches. Alternatively, field-to-lab test beds can evaluate baseline voice communications via rhyme testing. This emerging methodology algorithmically models human auditory systems and uses a rhyming profile of short words and phrases to test intelligibility. Testers can add artificial impairments and examine “what-if” scenarios to optimize infrastructure against a variety of potential future conditions.
• Video performance: Smart bases use video in a variety of ways, including for both humans and machines. In addition to video calling, installations in forward- and rear-facing installations may share real-time video uplinks, monitor warehouses and supply transport logistics, and more. It is therefore essential to ensure that video communications are clear and free from pixelation and other degradations. Smart bases can employ field-to-lab evaluation frameworks to continuously monitor video streams and conduct automated testing for quality and reliability. These test beds replay real-world data captured from machine-related field environments to evaluate the performance of data transfers and identify sources of pixelation and other quality issues.
• Three-dimensional terrain: Topographical characteristics of a given base environment – forests, hills, valleys, and other features – can significantly impact communications. Field-to-lab testing enables testers to visualize captured field data overlaid onto 3D maps of the environment. In this way, they can more accurately translate test results to real-world optimizations, such as identifying exactly where antennas should be placed to achieve the best performance. (Figure 1.)

[Figure 1 | An Army signal-support specialist prepares a high-frequency radio system during a battalion field-training exercise at Fort Sill, Oklahoma. Commercially available 5G technology, due to its high frequency output and smaller size, enables easier integration of the systems on to Army platforms. Photo credit: U.S. Army/Sgt. Dustin Biven.)

Enabling tomorrow’s smart bases

These field-to-lab evaluation capabilities can dramatically expand the toolset available to DoD planners and other stakeholders to ensure high-quality, highly reliable communication in locations where it is needed most. These capabilities are now extensible to practically any environment, through trusted military and government technology partners.

Note also that this model need not be restricted to standing up new infrastructure: By implementing field-to-lab evaluation as an automated, continuous testing framework, stakeholders can monitor smart base environments on an ongoing basis, diagnose new issues as they emerge, and measure the impact of planned technology changes before they are put into production. They can ensure that high-quality communication is always available for tomorrow’s smart military bases, even in the most challenging forward environments.

Stephen Douglas heads Spirent’s market strategy organization, helping to define market positioning, future growth opportunities, innovative solutions, and disruptive technologies. Stephen also leads Spirent’s strategic initiatives for 5G and future networks and represents Spirent on a number of industry and government advisory boards. He has more than 24 years of experience in telecommunications and has worked across the industry with service providers, network equipment manufacturers, and start-ups.

Spirent • https://www.spirent.com/