RFID Abuse, Human Tracking, and more...

[Nikita]

Thanks for the info :-)

Now, if you want to see something that's really open to abuse in the wrong hands, look into some of OnStar's surveillance capabilities (from archive.org as original has expired). Interestingly, that particular case was ruled to be an illegal wiretap, but not because of privacy concerns. Why anyone would order this system is beyond me to begin with, but this just makes it even worse.

Agreed there. A lot of newer model chevys and Buicks are coming out with this "feature" Standard. There is a website I found just now that talks about how to modify an onstar unit. In the wrong hands or in the owners hands, whichever.

[skroo]

Just for info, there is a service built on top of RDS called RASANT, which broadcasts RTCM corrections to GPS receivers. Today, with WAAS and SA switched off, it has become a nice toy.

Good point; I'd forgotten about this. Any idea if it's been implemented on US-based stations supporting RDS?

Besides, TV signals are usually designed not to overlap, so how can one get the signal from the same station, off different transmitters?

With digital, this may be possible under the right circumstances if they're using a spread-spectrum transmission method, but even then, you're right: it's just a bad idea.

Are they going to get all the TV operators to agree on something?

Probably not unless the FCC mandates it, and given their track record I'm not holding my breath.

Agreed there. A lot of newer model chevys and Buicks are coming out with this "feature" Standard. There is a website I found just now that talks about how to modify an onstar unit. In the wrong hands or in the owners hands, whichever.

Pretty much anything made or owned by GM in the US is going to have it. What's interesting is that some non-affiliated manufacturers offered it in the past, but I notice that that list has shrunk somewhat for 2006 - Audi, Subaru, and Volkswagen are all off the list; Oldsmobile's not included since GM killed that division.

It's been a long time since I looked into OnStar, but from what little I remember it ran over regular AMPS cellular frequencies; can't remember how data was carried, but I want to say it involved muting the earpiece audio while it was transferred in-band. Rather scary when people are encouraged by the literature in the vehicle to provide all of their personal information over OnStar itself in order to expedite their activation - not to mention the potential for fun and games with data interception and injection.

[Voltage Spike]

the GPS coordinates of the tower are known, and calculations determining position are made by differentiating signal strengths. This can lead to a fairly wide margin of error (usually greater than the local GPS accuracy offset) based on availability of towers, signal reflections, and other factors.

Sort of a side topic, but...

How many towers would a cell phone normally be working with to determine position? I would think the (generally) large number of high-power television transmitters would alleviate many of the accuracy problems. Other press releases indicate that the system has already passed E911 testing in indoor, urban environments.

The same group is also pushing a system whereby emergency personnel surround a building with a few transmitters for 3D positioning of anyone they send in.

I'd also be curious to take a peek at how they convert the image down to something small enough to transmit but unique enough to determine timing information.

All in all, it appears to be a very interesting technology.

Besides, TV signals are usually designed not to overlap, so how can one get the signal from the same station, off different transmitters? Are they going to get all the TV operators to agree on something?

Simple: they don't attempt to control the radio signals at all. They appear to use all of the stations independently (quickly cycle through the frequencies?) and they don't require the station to be anything beyond a standard transmission.

I don't see any mention of how they are going to handle the imminent transition to digital-only broadcasts, but I'm sure they have a plan for that.

[skroo]

How many towers would a cell phone normally be working with to determine position?

Typically two: the one that it's currently homed to and whatever the next strongest one is that it can see. No reason why it couldn't use more than that, though, or even just one emitting source: I'm pretty sure I posted a thread on this a couple or three years ago, but can't find it right now.

I would think the (generally) large number of high-power television transmitters would alleviate many of the accuracy problems. Other press releases indicate that the system has already passed E911 testing in indoor, urban environments.

I'll take a 'maybe' on the accuracy statement. It's entirely possible that it works flawlessly, but it's equally-likely that it has some issues that haven't cropped up in testing yet. For my part, I'd really like to know how it deals with reflections.

All in all, it appears to be a very interesting technology.

Definitely, but we really don't need another standard - we just need to make the existing one work more effectively.

I don't see any mention of how they are going to handle the imminent transition to digital-only broadcasts, but I'm sure they have a plan for that.

Doesn't matter - most major cities are already broadcasting digital alongside analogue, and they're only backing off of the digital transmitters.