So yeah. The thread title.

I always avoid dropping a GPS into my build setups because I see them as being a liability. I can't imagine that the satellite used to provide your positioning data to you couldn keep a record of that data. And we all know how data trails can be an issue should a GM take such an issue.

Any idea what the deal is here? Would the GPS company keep such info privileged? Could someone sniff out your GPS code and find you whenever you have the device on? Is it even encrypted?

Thoughts?

Currently, standard GPS appliances are only a passive receiver. It receives GPS sats constellation signal and compute its position accordingly. Then, instead of displaying it on a screen, it can transmit the result to a Facebook app, the Pentagon or the Illuminati HQ, just like any processed data, but that's not a feature of GPS technology.

Yeah, I was going to say... that's kind of a weird question. I mean, if the satellites had to receive data from every single GPS device, well, that's be some serious hardware. They just sit up there broadcasting where they are, and the devices take that information and tell you where you are relative to the satellites. No?

Yes. As we saw in James Bond, the only 'unsafe' thing about GPS is if the signals are false; there's no record unless *your* GPS sends your position to someone (like some cell phones do today).

One of the misconceptions of electronics that Hollywood has perpetrated is that you can never be sure who is listening in. While that is a good thing to keep in mind if you aren't trained in electronics, your technitian can guarantee that you don't have any electrical bits sending off cryptic messages on occasion to the big bad data collector in the sky. Or at least, they can guarantee that at the time they give you the product. Subsequent hackings and jackings can get you tapped and bugged, or else Burn Notice would be out of a job.

A commlink can act as a GPS, but only in wireless enabled areas (cities.) With a GPS, you know your position and velocity, anywhere, at any time, except underground. A commlink may be able to use underground wireless nodes. If you disable the GPS's wireless (as opposed to it's receiver), only someone looking at the GPS's screen knows the information. Setting the GPS's signal rating to 0 will allow you to view the data in AR, and only people within 3 meters of you have a chance of hacking the GPS. Both a GPS or a commlink would log your route, a problem if it falls into the wrong hands. These logs can be disabled and deleted.

A GPS company would have no information beyond your GPS serial number and SIN. They may be able to copy your logs when you return to a wireless area. Third-parties could only detect your GPS if they were within it's signal range. The GPS has two signal ratings, one for receiving satellite signals (signal 8, receive only), and one for data communication (signal 2, two-way). I'd say the data is only encrypted if you install Encryption software on the GPS.

Pretty much every comm would have GPS. It's pretty common nowdays. In sixty years, GPS would be an integral part of numerous standard apps on the cheapest commlink. But the GPS chip doesn't communicate with the outside world - only with your apps. So just make sure your apps aren't doing anything you don't want them to. But no one short of an expert (hacker) will be able to shut them all down. Five years ago, I had a security system on my computer that let me specify whether every individual program could reach the internet or not. I no longer have that software, and I have many more programs that send and retrieve information. It's only going to get worse.

There are a number of programs that provide 'outgoing side firewall' for Windows (I think ZoneAlarm was the most popular?), and a couple for Mac. I never understood why it wasn't built right in to the stock firewall, but that's reality for you.

In Shadowrun, you could make it a simple computer use test to configure something like that, and/or allow people to find commercial/open-source options to do it for them; it might even be a basic function of Firewall programs.

I think I used to use Zone Alarm. I should find it again.

But in 207X, there are so many programs running on your comm, that I don't think you could shut them all in. And what effects would that have on your comm or its security? You could prevent security updates. You might not recognize which ones are bad and which ones are good. There would be all kinds of ware designed not to show up on the proper lists.

Things are always in balance. Did using ZoneAlarm prevent security updates? Did having too many programs cripple it? Did it make your security worse? Did it recognize good/bad wrong? (This one is a 'yes', but that's intentional: you instruct it.)

iirc, it is built in, only that its disabled by default. I suspect thats a ease of use issue (less "incomprehensible" popups that ends up getting a yes by rote anyways).

and iirc, GPS is integral to how AR works. For the comlink to display AR signs and such in the right place, it first needs to know where itself is. And if your comlink is in active move, or in some other way transmitting AR data thats supposed to be displayed in relation to your comlinks location, it by default is sharing the location data with anyone within direct broadcast range.

and GPS is basically radio triangulation. And this can also be done without a GPS signal. and if one have 2 or more antennas with known locations, they can pinpoint your transmitter by drawing a virtual circle from each and looking at where the lines cross. The latter being basically what a GPS device is doing, in reverse.

Right, but the fact that GPS is the reverse of triangulation (which you can do in SR4, also) is very important for security; it means that your GPS location is only shared with others if you *want* to.

As for how AR works, I assume you just mean location-based adver-services. Runners probably don't want those anyway, but regardless, you should have control over whether that info (GPS) is sent or not; they'd probably just use Skyhook-style locating, anyway, which basically like GPS-lite (and you should still have control over access, because it happens on your commlink).

The "GPS" that you have on modern cell phones and on SR4 commlinks is a misnomer; it's not based on satellite signals, it's based on signals from cell towers and/or wireless networks. Take your cell phone/commlink out to the middle of the mountains where you've got no signal, and poof, the "GPS" function doesn't work; interestingly, they can be quite accurate in places that have been built to take advantage of this technology (within a meter).

True GPS is based on satellite signals, and will work fairly accurately pretty much anywhere you can get a clear signal to 3+ specific objects in orbit above you. Current tech lets GPS map your location down to within a few meters, good enough for navigation purposes but not quite accurate enough to do things like map property lines or underground gas pipes so you don't dig in the wrong spot. By 207X, they may have become more accurate.

That's not strictly accurate...
...Modern phones have GPS chips, which locate via satellite, and they also triangulate via cel towers and wifi hotspots - they usually flip from one to the other according to signal strength, etc though some might be able to prefer one over the other.

An example is the early iPhones, that didn't have GPS, but could use google maps...
...Wheras later models do use GPS, and fall back to cel towers and wifi hotspots if they can't use the GPS.

Right Shrike30, that's the Skyhook-style location service. There's no reason your phone (today) or your comm (SR) can't have real satellite GPS though.

If someone were to put their Commlink in "hidden mode" does any part of that translate to essentially shutting off the GPS function?

No. Again, the GPS (and Skyhook-type systems) are passive from the outsider's perspective.

there is also something called A-GPS. This basically gives a faster lookup by first asking the carrier who's network your using, where the cell your in is located. This is then used to speed up the initial GPS startup as otherwise the phone would basically just look for whatever sats it can see, check the time and date, and by that figure out in what part of the world you would see those sats at that date and time.

Ok, I guess I haven't read the Matrix rules in SR4 closely enough or at least my understanding of it isn't what it should be. I sort of got the impression that while using a commlink in SR any local calls (or at least those within the comms signal range) were straight comm to comm connections and not routed through some sort of cell tower and that only connections outside a comms signal range would need to go through a cell tower. I also envisioned that one benefit of being in 'hidden mode' would be to make it more difficult to triangulate your position.

It is. There really is not a 'cell system' like 2010. The Matrix is fluidly routed through anything and everything in signal range, including your commlink, your car, or large-scale towers.

Hidden Mode makes it impossible to see your node at all without resorting to a Detect Hidden Node (Electronic Warfare) action (SR4 p230). A successful Trace User action can give you a wireless user's location within 50m. If you steal their GPS/wireless location data directly, you get within 5m.

By RAW a commlink does NOT have Sat-based GPS. It only triangulates based off of your matrix connection. If you want a true GPS system you need to either buy a standalone GPS receiver, get a survival knife (1/4 the cost of a standalone GPS receiver ) or get an Orientation System.

GPS = Global Positioning System. The acronym itself has nothing to do with satellites. Earth's first Global Positioning System happens to consist of satellites.

Interesting point...

That's not completely true, at least as far as I understand it. NAVSTAR GPS is what we commonly call "GPS", which stands for "Navigational Satellite Timing and Ranging - Global Positioning System" and is the name of exactly one kind of satellite network used for this system.

There are other systems used for satellite based navigation (like the Galileo system europe is working on) but they're not called GPS.

not the first time, there was a similar knife in older editions that came with a trauma patch. The claim was that one could buy the knife in bulk, extract the patch, and sell the patch back at a profit.

sadly, the wording related to that is anything but detailed.

You can buy a GPS unit, but it doesn't really matter. Matrix-based triangulation is essentially identical for these purposes.

Sure, but it's the S in NavSTAR that indicates the satellite. GPS can use satellites, and the NavSTAR GPS does use satellites, but other Global Positioning Systems don't have to. Any identifiable structure with a known long/lat/alt coordinate can be part of a Global Positioning System.

The thing is, as far as I know, there is no "other" Global Positioning System. At least, I've never heard the term used to describe anything but the NAVSTAR GPS (Galileo at least is never described as a GPS, only as a satellite navigation system), and in fact I think it is probably trademarked and it might be illegal to call your "own" navigation system a GPS.

So yes, in theory, if we only look at the meaning of the acronym itself, you're right, but in practice, it's a trade name for one specific system.

There may be other global positioning systems which don't use sats, but there is only one Global Positioning System and that uses NAVSTAR

I can only assume you are trying to prevaricate by stating that GPS does not automatically assume satellite navigation. There are no land-based systems now, or planned anytime in the future, that have a global reach.

In addition to Galileo there is the Russian GLONASS which is now almost fully operational again. Most decent GPS recievers will use Galileo and GLONASS in addition to NAVSTAR -- better recievers can also use differential correction from beacons (really accurate readings usually require post-processing though).

And the Chinese are working on their own system called COMPASS. This one is quite similar to Galileo or the next generation of (NAVSTAR) GPS satellites.
The land based LORAN-C system was used for military and commercial sea navigation and had a large reach. But it was not global and mainly for the coastal areas. And by the U.S. it has been decommissioned this year.

as if it was not crowded up there already...

Jesus, who cares? Questioned answered about 12 posts ago: 'GPS' don't necessarily mean satellite GPS, except it basically does.

The more interesting question is whether or not GPS signals can be spoofed or faked.

Speaking from real-world experience in the cell phone and GPS business, GPS signals (NAVSTAR, if you want to be particular) are relatively easy to simulate and spoof. Current cell phones with (NAVSTAR) GPS use the existing cell phone network to give a first-pass location, which cues the phone on what GPS satellites to look for. I would imagine that in 207X, there are several localization systems in place, and the average commlink uses a bunch of them in coordination. However, those localization signals are broadcast signals, and low-power signals at that. As such, it wouldn't be that hard to generate false signals that a device would consider as genuine. The complication comes when the device thinks it's in the wrong place, and starts behaving oddly. In a dynamically meshed network like SR4, it could start interfering with the operation of the network in the area - though the protocol likely has ways of dealing with that problem fairly rapidly.

In game terms, I'd quite happily let any hacker with a commlink and some Electronic Warfare skill spoof a targeted commlink into not knowing where it is. Probably just use the exploit rules, but using EW skill and Signal ratings. Likewise, it would be a very basic hack to have a device send out an incorrect location. I'd give spoofed devices periodic chances to notice something is wrong or stop working. Throw in the fact that some commlinks have bad reception in the area for color, and call it a day.

-- Yes, but with some caveats.
1) Everyone and their dog uses GPS so you're not doing your side any favors. In Shadowrun, all that AR stuff requires good positional information.
2) Antennas are often directional on hardened devices. In Shadowrun, more than one navigation network will use encrypted signals to reduce spoofing.
3) Most of the stuff you REALLY want to jam has inertial navigation backups and checks. In Shadowrun this includes optical navaid recognition.

Actually, that's a good point. The other systems I was thinking of, such as my mobile phone, aren't global systems. They're limited to populated areas. They'd need countless radio-buoys at sea that could hold a constant lat-long position to pull that off.

Today's only global positioning system is satellite based. My argument was purely language based.

personal location out at sea (or in the air) will be somewhat pointless as you will most likely be in a vehicle (and if not there is more pressing matters to deal with) that already have sat based GPS, or some other long range means of knowing where the hell it is at any given moment.

heck, i think there have been several systems for location and direction finding for both sea and air ever since the development of radio. And especially after one got transistor based calculation and timing, as then a box could do the job that was earlier done by a analog clock and a sextant.

here for instance is a ground based system for aircrafts:
https://secure.wikimedia.org/wikipedia/en/w...rectional_range

tune in two or more of these transmitters and you have something very similar to GPS.

Well, I was actually worried about the GPS peripheral device, the Sat-linked one, whether or not it would keep unwanted positioning records and who might be able to access those records. The benefit of a sat-style GPS being the high signal to defeat jamming for use in a sloppy Orientation system.

I suppose you could keep it wiped just like with the comlink GPS, but the topic in general does offer up an interesting opportunity for a good tracking Worm...

A GPS device probably would keep records; certainly if you wanted it to. The nice thing about SR4 abstract electronics is that everything is basically user-configurable in that way. I just wanted to point out that it doesn't really matter whose satellite does what, right?

Except a matrix signal can be jammed. If you want to know where you are at all times of the day, you have to have a Orientation System.

An Orientation System is somewhat cheap and takes up only 1 capacity in a cyberlimb.

Sat-GPS can be jammed as well. You're right, you need inertial… as if that would ever come up.

Considering that it only costs 1200 for an Orientation System and that you can put it into a cyberlimb for only 1 capacity, it's a steal.

Couple it with a Radar sensor (Rating 4) and you can create maps of a building on the fly.

Except for when your radar gets jammed too.

I wonder if your comlink's ECCM carries over to the UWB in your cyber?
If not, it'd probably be better to slap UWB into an MCT Flyspy and just have it feed the info into your PAN...