Since 2014 when Russia began threatening and invading its European neighbors (especially Ukraine and the Baltic States) NATO has learned a lot more about Russian post-Cold War EW (electronic warfare) capabilities. The fighting in eastern Ukraine (Donbas) led the Russians to use a lot of their most modern electronic warfare equipment. Not just Cold War era stuff (which Ukraine inherited a lot of after the Soviet Union collapsed in 1991) but equipment NATO knows was developed in the 1990s or later but not encountered until now. NATO now believes that Russia has developed effective and reliable encrypted battlefield radios that are proving very difficult for Western forces to decrypt or jam. As expected, Russian eavesdropping and jamming gear turned out to be very effective. This Russian gear has greatly aided the rebels, who have neither captured any advanced Ukrainian electronic warfare equipment or possess the number of electronic warfare experts needed to operate the equipment required to explain the amount of jamming and eavesdropping the rebels are being supported with. Thus the rebels can jam or eavesdrop on all manner of Ukrainian communications (cell phones, military communications and control equipment for UAVs and anything else operated remotely) and jam those communications as well. It also appears that the Russians have not used all the capabilities of their electronic gear.
At the request of Ukraine NATO has provided a growing electronic warfare support effort and there has been, not surprisingly, little publicity about the result. That is typical when it comes to electronic gear in general, which is much more effective if the other side does not know much about how it works. This is nothing new. For example the World War II strategic bombing campaign against Germany saw nearly all the modern electronic warfare techniques (and countermeasures) being developed and used for the first time. The Russians captured a lot of the German stuff and were impressed. Thus they never exported a lot of their best Cold War era stuff and most of this gear was never seen in action. After the Cold War Russia continued to develop electronic warfare equipment and now, in Ukraine and the Baltic States, NATO is getting a better idea of how much trouble they are in. A lot, it turns out.
In Ukraine NATO electronic warfare experts have had ample opportunity to get a better understanding of the latest Russian electronic warfare gear under combat conditions. That is important because Russia now exports a lot more of this equipment. The Russians don’t mind making their electronic warfare tech more vulnerable to theft because Russian manufacturers need the money to stay in business. Meanwhile NATO would simply like to know more about the latest Russian gear, just in case.