Military Communications and Information Technology: A Trusted ...

Chapter 1: Concepts and Solutions for Communications and Information Systems
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A coarse model for jamming effective range, that should be workable in any
situation for the most of the world, is presented in [6]. Maximum effective range
is given by
where necessary jamming power P J is
(2)
P t – effective power output by the enemy transmitter;
H J – elevation of jamming antenna above sea level;
H t – elevation of enemy transmitter antenna above sea level;
D J – jammer to receiver link distance in km;
D t – enemy transmitter to receiver link distance in km;
K – jammer tuning accuracy: 2 (for FM in VHF), 3 (for CW or AM in VHF);
n – terrain and ground conductivity factor:
5 – very rough terrain, poor conductivity;
4 – moderately rough terrain, fair to good conductivity;
3 – rolling hills, good conductivity;
2 – level terrain, good conductivity.
IV. Aspects of effective RCIED jamming
As it was already mentioned, the trigger for RCIED can be both a mobile phone
and modified remote control device for a child’s toy or other easily and cheaply
available electronic gadget (fig. 1). All of those transmission systems can be jammed
by suitable transmitters that can provide some protection around a vehicle or a patrol.
The size of the protection zone depends on the JSR – relation of the jammer’s
power to transmitted power of the device used to trigger the IED (1).
Radio jamming not only prevents the remote detonation of RCIEDs but also
obstructs the communication channels of terrorist or riot organizers. Unfortunately
it can have influence on our own radio communications.
Therefore it is important to design jammers which can leave ‘windows’ to
enable friendly communications. Such intelligent, working in a reactive mode, jamming
sets deployed on mobile platforms have already a few implementations, e.g.
the Crew Duke [10] used by the U.S. Army.
RCIED jamming is different from typical electronic warfare involving actions
taken to impair the effectiveness of hostile electronic devices, equipment or systems.
In military receiving equipment, in contrast to RCIEDs, are implemented ECCM
(3)