Besides where you jam, it matters what you jam with:
- Noise jamming (wideband, partial-band or pulsed): simply raises the noise floor until the receiver loses its bit or voice quality.
- Tone / multitone: a few carriers that upset specific demodulators or control loops (AGC) — more economical than wideband noise.
- Protocol-aware / smart jamming: attack the weakest link in the protocol — the synchronisation or pilot signal, the control channel or the acknowledgements (ACKs). By jamming only the sync you can bring down an entire link with a fraction of the power of brute-force jamming.
Key point
Smart jamming is the communications counterpart of deceptive radar jamming with DRFM (EW receivers & DRFM under the bonnet): not shouting louder, but hitting precisely the most vulnerable function. It does require good COMINT beforehand — you have to know the protocol to find the weak spot.