Recent global conflicts are dominated by stories of inventive drone attack strategies and low cost, high-volume drones punching well above their weight. The current state is the  culmination of years of advancements in three different technical areas: increasingly capable  and available commercial drone subsystems, military use of ever smarter missile systems, and  advancements in communications techniques. Each of these capabilities were advancing rather  independently and without much understanding of the complexities involved from one industry  to the next.

Before the war in Ukraine, drones were navigating via GPS and actively controlled by a pilot  communicating using a single, fixed frequency that was probably WiFi or LTE. That recipe yields  a chain of single failure sources, easily exploited by Electronic Warfare (EW) techniques.

EW techniques are now at the center of all modern conflicts and the battle of drone vs. jammer  is the new arms race producing increasingly capable and creative Unmanned Systems, whether  by land, sea, or air. These techniques, and ways to counter them, are in use in every possible  dimension of Unmanned Systems.

Tethering

By unrolling a thin spool of glass fiber as they fly, these drones maintain a physical, un jammable link to the operator. This technique has proven effective in contested and congested  RF environments where radio signals are completely saturated. The limitations are clear,  however, as the drone mission is limited to the range of the tether and there have been  successes in tether clipping tactics.

Navigation

GPS systems are relatively susceptible to the use of jamming and spoofing meaning their use in  navigation is a point of vulnerability. Jamming interferes with reception of the GPS signal while  spoofing introduces false positioning information, both of which can render a drone literally lost  in space and unable to complete a mission or return. This GPS attack is just as effective and far  less expensive than kinetic attacks.

There are now multi-constellation, jam-detecting, spoof-detecting GPS receivers able to deflect  these attacks and, increasingly, techniques like inertial or visual navigation that make use of AI  and don’t rely on GPS for positioning at all. By using onboard cameras and pre-loaded satellite  maps, the drone “sees” the ground to determine its location, making it entirely immune to GPS  spoofing or jamming.

Command and Control

A single operator in constant communication with the drone requires continuous RF  communications between the operator and the vehicle and provides an opening to detection,

location, jamming, and spoofing of both. There are two general strategies employed in  combatting these threats: autonomous drone actions and resilient and stealthy  communications.

The more autonomous the decision making of an Unmanned asset is, the fewer commands are  required from an operator. However, as the offensive capabilities of these assets increase,  defense organizations are insisting on keeping some level of human control in the decision making chain. Reconnaissance and target acquisition are increasingly autonomous capabilities,  but systems continue to require some amount of human participation and, therefore, RF  communications with the system.

RF communications for command and control of drones have advanced to using various  combinations of spectrum manipulation techniques, all in pursuit of maintaining manual control  of drones while reducing the risk of detection of the RF signals:

• Mesh networking – Adding nodes to the communications systems providing a level of redundancy to the system and allowing sharing of information from the drone with other participants.
• Interference avoidance – Detecting interference and selecting a new single frequency for operations.
• Fast frequency hopping – Rapid tuning to multiple frequencies for communications to limit, confuse, and evade enemy EW assets.
• Spread spectrum – Spreading out the transmission signal to make it harder to detect. Swarms and Attritable Assets

In swarms, a group of drones communicates with each other and an operator via a mesh  network. Each drone in a swarm is capable of independent navigation and mission  advancement. Combine that with the rise of attritable vehicles – drones so relatively low in cost  that they are treated as disposable – and swarms become capable of more complex strategies.  They may have decoy, self-destruct, kamikaze, and redundant elements combined in a single  highly-effective offensive mission.

Escalation

One key element to these EW tactics in the race for supremacy is the Software Defined Radio (SDR). While it is possible to get a small radio with a specific feature set to perform some of the  tactics described here, an SDR can be continuously upgraded and reprogrammed as better  capabilities and features are developed. The more processing power on the SDR, the more  capable of feature expansion the platform becomes. The higher the radio transmit power, the  longer the communications range. Conversely, the lighter the radio solution, the less drain on the system battery and the larger the mission runtime of the system. SDR producers are in  their own contest for the best Size, Weight, Power, and Cost (SWaP-C) offerings while continuing  to the push the boundaries of RF communications technologies.

The integration of Electronic Warfare into drone technology has moved from a niche technical  requirement to the very heart of global defense strategy. The best drone is no longer the one  with the fastest engine or the largest camera, but the one that can navigate the challenges of  modern communications technologies.

Governments are pivoting from a few high-cost, vulnerable platforms to swarms of low-cost drones, employing advanced EW techniques, yielding a solution of nested redundancies. By  combining EW knowledge, swarm tactics, and prices allowing sacrifice of assets, there is no longer a single point of communications failure nor a single point of mission failure. This is the  new overwhelming force.