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Training Slides. Code 5774 Naval Research Laboratory Washington DC, 20375 202-404-7616 (DSN) 754-7616 builder@enews.nrl.navy.mil builder@nrl-dc.navy.smil.mil https://builder.nrl.navy.mil https://builder.nrl-dc.navy.smil.mil. Day 1 Exercise.
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Training Slides Code 5774 Naval Research Laboratory Washington DC, 20375 202-404-7616 (DSN) 754-7616 builder@enews.nrl.navy.mil builder@nrl-dc.navy.smil.mil https://builder.nrl.navy.mil https://builder.nrl-dc.navy.smil.mil
Day 1 Exercise • There is a civilian cell phone network in Baghdad. • There is a group of friendly vehicles traveling through the area. • They have an independent comm system • They’ll jam the civilian network as they pass through • To save time, we’ll use the cell towers and hummers modeling in Chapter 11 • Open the CellTower lab in the tutorials directory • Save to an alternate scn on your desktop • Remove the UAV • Remove the network
Civilian cell towers • Reposition the two existing towers, and add a third tower by exporting/importing the tower. Use the following positions. • Tower A • Latitude: 33.3039 • Longitude: 44.4942 • Tower B • Latitude: 33.3291 • Longitude: 44.1188 • Model the signal coverage of the civilian network • Use SNR plots. Ignore jamming; we’ll add it later. • Assume Minimum SNR is 7 • Assume Ideal SNR is 15 • Increase the towers’ Tx power to 30 W
Civilian Network Coverage • Model the signal coverage of the civilian network • Use SNR plots. Ignore jamming; we’ll add it later. • Assume Minimum SNR is 7 • Assume Ideal SNR is 15 • Increase the towers’ Tx power to 30 W
Friendly Transit Path • Use this path to reposition and define Hummer 1’s motion • Initial Point: • Latitude: 33.3835 • Longitude: 44.4641 • First Waypoint: • Latitude: 33.3186 • Longitude: 44.4068 • Second Waypoint • Latitude: 33.2319 • Longitude: 44.4116 • You can leave the velocity at ~49 knots, it’s ~55mph
Reducing Unnecessary Calculations • Models of jammed comm networks take a lot of time (longer than jammer radar plots) • To reduce unnecessary computations, we want to limit area that we calculate signals for. • Add an overlay to the Hummer that shows range rings up to 3000 ft. • Use whatever division distance seems good. • Then crop the plots of civilian tower coverage so they only cover the transit region…
Reducing Unnecessary Calculations • Results of my cropping… • Tower A: • Range: 7 km – 12 km (4.35 mi - 7.45 mi) • Azimuth: 220 – 350 • Tower B: • Range: 25 km – 35 km (15.5 mi – 21.75 mi) • Azimuth: 77 – 115 • Reducing divisions to 10 for range and 20 for azimuth should maintain reasonable calculation times; we’ll bump up the resolution later
Friendly Jamming • Add a jammer to the Hummer • Antenna: Isotropic • Gain: 1 dBi • Tx: 1800 MHz (same as towers) • Bandwidth: 5 MHz(should be at least equal to tower bandwidth) • Power: .5 W • System Loss: 2 dB • Height: 5 ft • What are the ranges of signal values from each tower along the Hummer’s path? • -100 dBW to -110 dBW from Tower A • -130 to -135 from Tower B • What is the signal strength of the jammer at 100, 300, 500, 1000, and 200 ft from the vehicle? • Plot the Jammer’s signal, use the plot tool in conjunction with range rings to see the signal values of -70, -85, -90, -95, respectively. • At what distance does the signal drop below -100 dBW? • ~1100 ft • Change the two towers’ plots to include the effects of the Hummer’s jammer (as noise)
Modeling Potential Receivers • So far, we’ve ignored the receiver’s capabilities. To get a better idea of jamming effectiveness, we need to consider what type of receiver we’re trying to jam. • Create a hostile land vehicle, location is unimportant • Add a comm device to represent a cell phone’s receiver • Use an Isotropic pattern • Gain: 0 dBi • Z Offset: 10ft • Rx: 1800 MHz • Rx Bandwidth: 1 MHz • Rx Noise: 5 dB • Min SNR: 7 dB • Ideal SNR: 10 dB • System Loss: 2 dB
Modeling Potential Receivers • Use the receiver you just created in Tower A’s signal plot • Opt not to treat jammers as noise • Move the Hummer to the spot you think will be most vulnerable (using the time-slider) • Crop the plot down to approximately match the extent of the range overlay you created before. • Experiment with how effective the jammer is against a range of receiver values • Use J/S (in the cell phone function) to define a jamming buffer • This controls the magenta section of the plot