The Electronic Warfare Package comes with advanced encoding/decryption systems, homers, jammers and ECM systems. It allows you to eavesdrop on the radio communications of others, to make your own communications untraceable and to jam all communication or electronic surveillance nearby. This last operation is electronically very noisy, even though people cannot pinpoint your location, they sure know something is out there.
In most situations, assume that a character with an EW pack is immune to electronic detection or eavesdropping, while he can roughly locate and eavesdrop on normal radio communications with an opposed Fix-It roll.
Two characters with EW packs or similar gear can counteract one another with successful Fix-It rolls, but they still cannot eavesdrop on each other's communications.
Similiar packages are available as normal portable gear, but the internal versionis is slicker and easier to use "on the go".