EW Academy · Contents · Chapter 24 · Nederlandse versie
Chapter 24: Communications EW & SIGINT
The communications side of EW: SIGINT (COMINT vs ELINT), and above all communications jamming (COMJAM) — the J/S contest at the receiver, types of jamming, smart/protocol-aware jamming, spread spectrum and mesh networks (DSSS, FHSS, MANET), and geolocation through TDOA/FDOA.
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24.1The communications domain
So far this course has focused heavily on non-communications emitters: radar, IR, laser, missile guidance. But a large part of the EW discipline is about communications — intercepting, locating, jamming and deceiving them — and about the…
Read §24.1 →24.2SIGINT: COMINT vs ELINT
An important insight: even without deciphering the content , traffic analysis provides value. A sudden increase in message traffic or the appearance of a new radio net often betrays an imminent action. COMINT and COMJAM are therefore…
Read §24.2 →24.3COMJAM: the aim and the J/S contest
To disrupt a conversation you do not have to shout louder than the speaker — only louder than the speaker at the listener's ear.
Read §24.3 →24.4Types of COMJAM
Read §24.4 →24.5Waveforms and 'smart' jamming
Besides where you jam, it matters what you jam with:
Read §24.5 →24.6Spread spectrum, hoppers and mesh networks
Modern communications are deliberately designed to resist jamming. Three concepts you will often come across — explained here:
Read §24.6 →24.7Intercept, DF and geolocation (TDOA/FDOA)
If several receivers hear the same signal at slightly different moments, you can work out where the transmitter is — just as you estimate how far away a storm is from the gap between lightning and thunder.
Read §24.7 →