Might the strategy of integrating phones into a unified distributed antenna system serve as a means to mitigate the impacts of Russian electronic warfare?

According to an American firm involved in creating a system in Ukraine, networked mobile phones utilizing specific software may provide a cost-effective and straightforward solution to counter the sophisticated electronic warfare tactics employed by Russia.

The electronic warfare strategies employed by Russia, such as signal jamming and GPS spoofing, create substantial obstacles for Ukrainian military operations, particularly in the deployment of drones and high-tech U.S. weaponry. Identifying and locating adversarial jamming systems generally requires advanced software-defined radios, a type of equipment that is accessible to the United States and other well-resourced military organizations. However, smaller forces like Ukraine's encounter difficulties in acquiring these critical assets in adequate numbers due to financial constraints.

Should a cost-effective system be created to identify enemy jamming technology, it could enable Ukrainian operators to reclaim a measure of superiority against their more formidable opponents. Additionally, this advancement might alter the strategies that cellphone network providers adopt to fortify their devices against complex threats.

In the vicinity of Christmas last year, the Ukrainian military reached out to Sean Gorman and his team at Zephr, a company dedicated to fortifying devices against GPS-signal interference. Zephr quickly sent six Android Pixel phones preloaded with their software to Ukraine, and in April, they initiated field tests close to the frontlines in Donetsk.

According to Gorman's statement to Defense One, the phones were secured to drones, installed in cars, and positioned on fixed stands. Furthermore, they have been conducting controlled experiments employing their own signal jammers to accurately determine the location.

The initial aim was to investigate if conventional consumer mobile phones, functioning collaboratively in a network, could uncover the presence of an entity engaged in jamming GPS location information. The findings indicated that by comparing the GPS signals received by different phones, it was possible to detect instances when one or more devices were being targeted.

According to Gorman, "Our approach fundamentally involves leveraging the sensors integrated into the phone. The primary sensor of value is the raw data provided by the global navigation satellite system (GNSS). This encompasses automatic gain control (AGC), Doppler readings, carrier phase, code phase, along with additional information that mobile phones collect about their distances from satellites, cellular towers, and other network components."

These sensors are integrated into smartphones by manufacturers to enable the devices to optimize their performance, including identifying the closest cell tower. The data gathered from these sensors is essential for the GPS-processing software that allows phones to accurately inform users of their location. Analyzing data from various smartphones can help detect which devices are under potential attack.

According to Gorman, the integration of computational AI in our backend, along with the sophisticated processing of signals and software, enables us to achieve much more. Instead of merely relying on sensors or expensive antenna arrays, there is substantial opportunity to network phones together, effectively creating a large distributed antenna system.

The assessments further disclosed novel understandings of Russian electronic warfare.

In the Baltic Sea, Russia is interfering with GPS signals, which causes receivers to show erroneous location data. NATO representatives have labeled this situation as dangerous for civilian aircraft. A widely employed strategy to combat drones includes the spoofing of GPS signals, tricking the drone into believing it is situated above an airport, thereby forcing it to either land or exit restricted airspace.

Ukrainian soldiers stationed on the frontlines in Donetsk often describe experiencing spoofing attacks directed at their drones. Nevertheless, Gorman and his team have identified that much of this reported "spoofing" is actually high-powered jamming. These jamming actions occur within the same frequency bands as GPS or GNSS, which causes them to resemble satellite signals. As a result, they generate phantom or ghost satellites in areas where such signals should not be possible, including beneath the horizon.

In a detailed analysis provided to Defense One, Gorman noted that the noise in question does not match the typical profile of a GNSS signal, yet it contains energy at the frequencies targeted by the receiver for satellite signals. The receiver's signal-processing algorithms rely on correlation techniques to identify and track these signals. When a significant jamming signal is present, it can lead to false correlations, causing the receiver to mistakenly perceive that it is detecting satellites that are not actually visible.

Operating under a contract with the Ukrainian government, the group is striving to enhance their research efforts to not only identify cell phone jammer but also to determine their precise locations, enabling strategies for avoidance or elimination.

In an email, Gorman explained that the new methodologies under development aim to estimate the location of signals of interest using three key inputs: 1. localization by range based on power; 2. localization by area of effect; and 3. triangulation of jammers through angle of arrival. Each smartphone will capture the interference signal, document the last known position, and timestamp the reception, creating data points across the network. The system will then aggregate and process these signals centrally to triangulate the jammer's location.

The U.S. armed forces are dedicating considerable resources to the development of alternatives to GPS, typically termed alternative position, navigation, and timing (Alt PNT), to aid various users, including individuals and drones, in accurately identifying their locations. Nonetheless, many of these investments have not demonstrated a favorable return on investment.

According to Gorman, the entire process is contingent upon having an initial known position, which is exceedingly difficult to establish without GPS technology.

The networked methodology will not serve as a substitute for other, pricier military systems intended for the detection and identification of jammers. Nevertheless, it provides a swift and economical solution for armed forces like Ukraine and other organizations that could be impacted by jamming, such as first responders. While it will not eliminate the need for alternative position, navigation, and timing solutions, it may improve their overall efficacy.

According to Gorman, it is possible that a fundamentally different approach could be adopted. Instead of directing all resources towards Alt PNT and GNSS resilience, which are certainly advantageous, we should investigate how this scenario has materialized. He pointed out the necessity of accurately mapping and understanding the area concerning the emitters, allowing us to circumvent those locations and eradicate the emitters.