[PrimeApe]

Every commlink has the ability to scan for wireless signals. Active and Passive commlinks will show up quickly. It does not state that this alone can tell you the range or location of these signal sources however core rulebook illustrations imply that it does.
(perhaps active commlinks will broadcast their GPS for the benefit of other active users)

For this argument we will assume that a commlink in passive mode can't be physically located.

I propose that if multiple users were to link their commlink's wireless detection abilities via a TacNet (UnWired page 124) could retrieve relative signal strength data from all coms in the net and triangulate the location of the opponent's commlink and overlay the location in their heads up display/AR. The assumption is that this would be done automatically based off the discription text of the TacNet (as an expert system designed to adapt, incorporate sensor data , analyze and predict ...etc)

Modifiers:  The closer the target to the sensor net, the more accurate it would be
                   The further apart the team members in the TacNet, the more accurate it would be.(like a VLA , V.ery L.arge A.rray)

For 3-dimentional mapping, the team would require at least one sensor/commlink/tacnet user to be above or below the rest of the team.

-this could also mean that ANY signal (RFID tags in your clothes, smartguns, area jammers, "SmartPack",etc ) could be triangulated provided at least two tacnet members are within minmum range of the transmitting source)

Questions comments?

[Sengir]

Have a look at the Telematics Infrastructure in Unwired

[sniperfox47]

As sengir stated the telematics infrastructure software is what you want. It's a software/program that you run which automatically links together various wireless sensors to collect and analyze wireless data and pinpoint other devices in passive or active mode. In addition it automatically scans for hidden nodes as well and can feed its outputs directly into a tacnet or any of the devices running the TI software and connected to that network.

Just to clarify though since I don't see it anywhere in the book is the below correct?

•Triangulating the location of a commlink in 2 dimensional
space would require 3 sensors in signal range (comlinks, RFID chip, ect.) running the telematics infrastructure software (each needs it's own copy right?) and in addition these three sensors must not be in a line. If there are only 2 sensors or if the three are in a line then it gives 2 possible points for the device.

•Triangulation in 3d space would require 4 sensors in signal range that must not be on a plane. If they are on a plane or if there are only 3 devices it gives 2 possible points for the device (provided no 3 sensors are in a line).

Correct the above 2 if they are incorrect since they are based off my understanding of trilateration which may be incorrect.

[PrimeApe]

I've had a chance to look at  Telematics Infrastructure and it says it only scans for hidden nodes once per minute rolling only it's rating.
R 1 to 6 (15+, 1 minute)
This seems painfully slow given that for anyone else they can make the test once per combat turn. It seems a miserable waste of money given it's sluggish performance.

Why not assign an agent program with the scan software loaded to scan for hidden networks (one check per Combat Turn) and when it succeeds, pass that info to the tacnet?

--Also the number of sensors used to triangulate a source on a flat plane , really you only need two if you're checking via signal strength, more if you're using signal delay (such as how they triangulate cellular devices). Our training on that in the army was pretty darned limited but I learned that much. --

[sniperfox47]

I've had a chance to look at  Telematics Infrastructure and it says it only scans for hidden nodes once per minute rolling only it's rating.
R 1 to 6 (15+, 1 minute)
This seems painfully slow given that for anyone else they can make the test once per combat turn. It seems a miserable waste of money given it's sluggish performance.

Why not assign an agent program with the scan software loaded to scan for hidden networks (one check per Combat Turn) and when it succeeds, pass that info to the tacnet?

You're missing the entire point of that part. The benefit to that is it does that *in addition* to all it's other bonuses automatically across the whole network. If your primary goal is to detect hidden nodes there are much better ways to do it, you're absolutely right, but it's a package that counts as a single running program (one that can even run on RFID chips), gives you all the information of surrounding devices, *and* automatically scans for additional hidden nodes. If you want to waste a couple more slots per device there's nothing stopping you from having an agent search for additional hidden nodes (and even feed that info back to the TI if you want), but you'll blow 2 extra running software (agent and scan) and probably can't get it to run on an RFID chip.

--Also the number of sensors used to triangulate a source on a flat plane , really you only need two if you're checking via signal strength, more if you're using signal delay (such as how they triangulate cellular devices). Our training on that in the army was pretty darned limited but I learned that much. --

Trilateration (How GPS, GLONASS, and GALILEO work) is based on the idea that you have two known circles (or spheres in 3D) each with a centerpoint (the scanning device) and a radius (signal strength or delay). When those two circles overlap you can identify two points (that may be in the same location but usually aren't) on a plane where the detected target could be. By adding a third circle (with certain constraints on the centerpoint) you can narrow that down to 1 point.

The relative strength of a signal only works if you know it's originating strength (and therefore how much it's decreased), which would give you your radius. That would equate to knowing the devices "signal" rating in shadowrun, and i doubt most devices broadcast that since, as far as I understand, it's a metagame abstraction.

Additionally if you throw the idea of trilaterating the signal out the window and instead just triangulate it,  you could do it with less devices, but *ONLY* if you have some way of knowing the relative direction to the target such as having a directional antenna.

All of that being said though, it's quite possible the TI works on "futuretech" and doesn't follow any modern system of determining location. There's no way to really say because it doesn't really say anything in the book (since it seems like it's mostly intended as an NPC software).