MD1 Jammer information

Q & A

1. Do you have a 'test stub' or 'test simulator' for testing against the websocket rather than needing an actual MD1? Our software dev has asked as we are doing some integration with our RF sensor.

Our existing communications method (API) is using web sockets as you are aware. We have some existing client side code to use this interface, however things move rapidly and we have just added a gRPC interface. Going forward this is probably the better, quicker and easier API to use. On our side of life all of our code is unit tested, including the gRPC interface so whilst we don’t have a ’test simulator’ per se we can provide something to talk to. Equally we can put a real Meteor on a VPN for more detailed integration.

2. Do you have any rough data on effective range for jamming with the Meteor and Meteorite specifically in the ISM bands (868MHz, 915MHz, 2.4GHz, 5.2GHz, 5.8GHz)

Complicated question - the answer is … it depends on a lot of factors. A Meteor(its) box has a certain amount of power it can transmit. How you program it chooses how much of that resource is spread over what threats/targets. The more threats you address the more diluted your energy. Equally different threat devices transmit at different power levels. And finally, and a very dominant factor, is how the jammer is used and deployed (elevation, open ground etc). If the ECM has clear line of site but the flyer doesn’t we get an advantage, and vice versa. We tend to talk about jamming ratios, where the ratio is the comparison of distance between the threat transmitter and the jammer. For 2.4GHz devices that transmit at legal levels we’d like to be in the 1:1 to 1:2 range. A 1:1 ratio means if the bloke flying the bird is 500m away from the drone the jammer would get a ‘kill’ at 500m from the drone, a 1:2 ratio is the flyer at 500m and the jammer gets a kill at 250m. For Futaba type links we’d expect to be in the 1:1 to 1:2 range, similar for most commercial 2.4 GHz type devices. The extreme of this would be something like an ELRS powered FPV drone with the transmitter wound up to half a watt where we’d be very happy with a 1:4 ratio. Tactics and training make a huge difference by placing the ECM in a sensible place. Equally the more targeted you can be the better - the more generic you make your waveform the worse the performance will be, the more bespoke it is the better you can make it. And Jerry’s final though is that using multiple boxes with different waveforms installed gives even bigger gains.

3. Jamming on Cellular phone bands

Jamming cellular systems in countries such as Indonesia comes with many unknowns. Jamming LTE is hard but we often find places in that region are highly unregulated with cellular base stations placed too close together, fighting each other and running at high RF power levels. Jamming LTE in central Bangkok for example is close to impossible. We also ask customers to think about what their threat actually is. For example south Thailand all IEDs are still 2G based so jamming anything more than that might be unnecessary. That being said our starting point should be a fairly powerful system assuming the cellular network is strong but not outrageous. A four stack system comprising variant B and variant C meteors would be a wise point to start discussions.

4. The user requested confirmation that the jammer's power output is 750 watts, whether it is 750 watts per module or per entire module

Output power: Each Meteor in the stack has two RF outputs and produces 150W or 200W depending on variant. Our four stack system produces 750W in total. There are 7 x 100W RF outputs and 1 x 50W output.

5. The user requested that the 20-520 MHz module be incorporated into the cruiser jammer system.

No problem, already fitted. A Cruiser system has the following standard stack-up:

​a. Variant A = Low 20-530MHz @ 100W + Mid 500-3000 MHz @ 100W

​b. Variant A = Low 20-530MHz @ 100W + Mid 500-3000 MHz @ 100W

​c. ariant B = Mid 500-3000 MHz @ 100W + Mid 500-3000 MHz @ 100W

​d. Variant C = Mid 500-3000 MHz @ 100W + High 2500-6000 MHz @ 50W

The stack-up can be changed but this is a good mix of capability for CIED purposes.

6. If the cellular signal is weaker than −120 dBm and  there are no other active transmitters nearby. the environment is line-of-sight with no obstructions,  Does the  jammer range could coverage 1,500 meters in its optimum power ?

The last question is a bit odd. If the cellular signal is down at -120 dBm or weaker then you’re either at the limit of sensitivity or below it so a cell phone won’t be working. They also don’t state the technology (2G, 3G or 4G). This matters because 2G, for example, can have the base station ramp up power as and when needed. If a jammer is turned on the base station will detect that and increase its transmit power so your -120 dBm suddenely becomes a lot higher. If we take the question at face value and say can we jam a radio signal at 1km if the RSSI is -120 dBm then the answer is yes but a huge amount more detail is required such as which frequency bands, just one cellular operator or all operators, what does the terrain look like etc etc. We’d likely be wanting to use a directional antenna(s) for this kind of application.

7. For the stationary Meteor jammer you have quoted for vehicle mount, what is its effective jamming range with Omni directional and Directional antenna?

There are a huge range of variables in jamming. We normally only ever talk about jamming distances in terms of ratios - how far away the transmitter directly affects how far away the jammer is. The below are wet fingers in the air.

What we see and understand is that other manufacturers quoting numbers - they are making it up, quite literally making it up!

​a. Omni jamming of GNSS should be in the region of many 2 - 6km

​b. In field test scenarios low power C2 links such as those used in COTS drones should be in the > 1km range for omni jamming

​c. In field test scenarios high power wideband frequency hopping C2 links should be in the hundreds of meters for omni jamming

Adding directional antennas adds in the order of 6 - 9 dB to the jamming signal power (+3 dB is a doubling of power). The difference this makes compared to omni jamming is not linear, but it practical situations 2x distance would be the order of the day.