[Vass654]

Hmmm. Herp. Yeah, I had that messed up. Sorry.

[Sichr]

OK. Here is what rules say:

sensors and Jamming Vehicle sensors are subject to ECM/jamming
(see ECM,p. 135, and also pp. 246 and 329, SR4A). If a vehicle’s Sensor rat-ing
does not exceed the rating of the ECM/jammer, the sensors
are effectively useless. This can be an important factor in sensor
targeting (p. 171, SR4A). ECCM software (p. 246, SR4A) may
be used to enhance sensors that are contesting against jamming.
Apply the ECCM rating to the Sensor rating when determining
if the ECM/jammer rating equals or exceeds it.
As an optional rule, the gamemaster can rule that jamming
impedes sensors, and apply the ECM/jammer rating as a negative
dice pool modifier to all Sensor Tests and Sensor Targeting Tests.

Which means Sensor targeting is affected by ECM, or better...it is impossible to target something that has higher ECM that you sensor rating is. RAW.
Now...what is the question again?

[Sichr]

No...most Missiles have Sensor lower tha 5, Highest being SA-53 SAM and a few others. That would mean, that with proper ECCM software they are still able to hit even ECM 10 target. This can be solved only by reduced signature. Stilll. it is great difference between being or not being hit by 20P AP -6 shit when sitting in your favourite Tbird.

[Michael Chandra]

So ECM on vehicles works against RFID tags, against weaker signal tracking devices on passengers, against hacking below ECM-rating signal+eccm and strongly messes with sensorlocks if the missiles aren't equipped with ECCM software?

[DamienHollow]

it won't fully block an RFID chip on the jammer/vehicle (Signal 1, 40 meters) unless the jammer is at least a rating 8 (range 40m.) If the signal of the device broadcasting has more reach than the jammer, then the jammer can't always reach the receiver. The receiving sensor is what the jammer needs to be in range of, not the broadcaster.

[Michael Chandra]

Oh? But doesn't that mean you're saying that a Jammer cannot ever block a Rating-2 Signal within the Jammer's range? That would mean Jammers would pretty much never work.

It says in the rules (SR4a p231) that any device with a Signal rating less than the Jammer's rating (and ECM counts as a Jammer) are jammed and lose wireless connectivity. Meanwhile, wi-fi inhibiting paint and wallpaper are treated like Jammers. "any Signal rating less than the negating system's rating cannot extend past the boundary."

So a device, such as an RFID chip, WOULD be blocked if it's within a jamming range at a signal above the device's signal. If my Jammer's active at Rating 6 and there's an RFID chip within 20 meters of it (and one can argue that ECM would broadcast from every part of the vehicle), it won't work anymore because its own Signal is jammed (6->2 > 1). Doesn't matter if there's someone at Signal 6+5 just 5 meters away from it, they're not in mutual signal range because the RFID tag gets cut out.

[Mirikon]

Jammers work if the transmitting or receiving node are within the jammer's range. However, because of the nature of wireless mesh networks, if one device is able to get a signal through the jamming, then other devices within the (modified) signal range will be able to, as well. So if the RFID is within a couple meters of a commlink that can still get mutual signal from a node outside the ramming, the RFID can use the wireless mesh to connect to the wider Matrix. That's how most people in places like Lagos have matrix access, afterall.

[Michael Chandra]

But that's based on Signal 0's 3m range, correct? If there's nothing within 3m range that can rout on the signal to eventually get outside jamming range, there won't be a mutual signal range, right?

[Mirikon]

Right. As long as there isn't a device (or chain of devices) within 3m, you can't get a signal.

[Michael Chandra]

Hm... That's with Jammers though... Wi-fi negating paint works different, right? Wonder what it'd cost to treat your car with it, to make sure RFID tags inside the car won't use Gridlink to rout the signal on.

[mtfeeney = Baron]

Wait, so all I have to do is have one device with a strong signal and everything else will work perfectly?  Then jamming seriously is worthless.

[Mirikon]

You have to have one device strong enough to get through the jamming, and the other devices have to be within mutual signal range to get to the device, even by 'chaining'. However, a high strength jammer will reduce signal ratings in its area by its rating, so a rating 6-10 jammer will knock out all but the best commlinks running some serious ECCM. But yes, jammers are best for up-close engagements, or when trying to cut someone (or something) off from the matrix when they aren't walking around with a milspec commlink, and are in an area with limited connectivity (like the barrens, or rural areas). It certainly isn't all-powerful, but it is far from worthless. You just have to play it right. Same idea as, say, suppressive fire. Not an all-powerful kind of thing, but when used with proper tactics, it can make life 'interesting' for those on the receiving end.

[Michael Chandra]

Anything jammed goes to signal 0, though I can't remember where that rule is located. Signal 0 is 3m range. With that in mind, jammed devices can stills end signals to each other as long as there is a chain possible where every link is at most 3m. If you got a good-enough on the inside, and a good-enough on the outside, then anything that can make a signal-0 routing chain to the good-enough on the inside will be able to talk with the outside. Of course not many people are walking around with ECCM on their devices, so unless you can connect with a Satellite (Signal 8 before ECCM) or have put up a communication device within reach, your ECCM still won't be enough to get past the jamming. Imagine being in the Redmond Barrens with Signal 4 and ECCM 4, that means you got a 1km range. If there's no Signal X+Y>=JammerRating within that 1km, you're still without connection.

[Sichr]

Jammers work if the transmitting or receiving node are within the jammer's range. However, because of the nature of wireless mesh networks, if one device is able to get a signal through the jamming, then other devices within the (modified) signal range will be able to, as well. So if the RFID is within a couple meters of a commlink that can still get mutual signal from a node outside the ramming, the RFID can use the wireless mesh to connect to the wider Matrix. That's how most people in places like Lagos have matrix access, afterall.

If RFID signal is blocked, there is no way it can reach that commlink. Even to ping the RFID with really powerful signal rating commlink would be impossible, since jammed RFID has signal 0, not in the meaning "Signal 0=3meters range", but "Signal 0=Ceased to exist".
Well RAW you would be right with the bridging/chaining IMO :p
IRL, in the jammed field all you can receive is signal static noise.

[Sichr]

And this has quite brutal effect on tacnets and secured/slaved networks. Since to Slave device, you need the subscription in the node, and it the subscription is terminated, in any node of the network, Master node is severed and goes to dumpshock. With EW drones, like Armadillo, this is pretty funny