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June 6, 2007

iphone

To those who think the iPhone has GPS, get lost

Posted Jun. 6, ’07, 9:55 AM PT by Dan Moren
Category | iPhone

noiphonegps.jpgYeah, let’s nip this one in the bud. There’ve been increasing susurrations in the Apple underground community that the iPhone is going to have GPS built in. I’m going to say that there’s a better chance that the device is going to work as a combination garage door opener and pumice stone.

But GPS functionality? Pretty darn unlikely, for a few reasons. Let’s start with the biggy: as others, including Senor Gruber, have pointed out, the iPhone’s already passed its FCC exams, with nary a mention of GPS. They can’t just shove a GPS chip in—that’d require getting the device recertified, which they’re not going to do this close to launch.

And if the iPhone did have GPS functionality, you can bet that Apple’d be talking it up. They gave us all the other specs at Macworld, why not mention it now? One site pointed towards the fact that Google Maps on the iPhone has a “directions” function as proof positive that it has GPS, leading to me wonder if the writers have ever used Google Maps? What makes them think that such a link doesn’t just prompt you to enter your current location? That’s like saying that since the iPhone has the ability to dial phone numbers, you’ll be able to send faxes from it.

(Hey, I’m watching you, rumor sites. If I hear so much as a hint of faxing capabilities, you’re going to wish you’d never even heard of an iPhone.)


10 Comments

Michael Long said:

Isn't there some FCC reg that requires the ability to determine cell phone positioning for 911 calls? You can have an idea of where you are w/o having full-bown GPS.

June 6, 2007 10:11 AM
Donn said:

^ Such a location system for cell phones is in the works in many states, but there's no standard and it's a big mess. I think integrated GPS is going to be the final solution in any case.

June 6, 2007 10:50 AM
Long said:

It's so weird. When I go on Google Maps, I see those links that give me directions. I might as well say that I have a GPS.

June 6, 2007 10:55 AM
halhiker said:

You can get position from the cell network; you do not need GPS. I read that some people thought it had GPS because when SJ demoed it at Mac World it showed his location. Hey dummies, for GPS to work you have to be OUTSIDE because you have to have contact with the satellites to give you the GPS reading. GPS won't work indoors and often won't work in canyons without a good view of the sky, or under heavy foliage. IF iPhone has some locator, it'll have to be related to the cell network

But it doesn't matter. I'll get one anyway.

June 6, 2007 11:32 AM
Joshua Orzech said:

What about "Location Services"? That is what my Sprint phone calls it. I believe it's a network triangulation tool which works similar to GPS in that it locates the user.

It seems the iPhone can use this information for a simple GPS implementation. This is very different from the common GPS devices that triangulate off of Satellite data. Just like satellite GPS will need line of site to the minimum satellite number, an iPhone GPS implementation would need to be in cell data range.

My Sprint/ Samsung i500 uses something called "location". This is what it reads in the preferences.

"Turning location on will allow the network to detect your position, making some Sprint applications easier to use. Tuning location off will hide your location from everyone except 911. Even if location is turned on in this handset, no service may use your location without your expressed permission. Your location is now available to the network. Sprint and those parties you have given permission to will now be able to retrieve your location."

June 6, 2007 12:25 PM
Peter said:

This is actually "phase 2" of the Enhanced 911 system, mandated by Congress back in 1998. The idea is that you can call 911 and yell for help and the information about where you are will be available to the 911 operator.

It's up to the cellular network provider to handle this--not the phone companies. The way Cingular appears to do it is through a system call U-TDOA. When you make a call, the network provider basically queries all the towers to find out when the signal got to each tower and computes the distance and direction from each tower and triangulates from there.

So the first issue is this happens when you make a call. So you have to be continually transmitting for this to work. That's going to affect battery life if you try to use it as a GPS. Also, there may be issues for the network if tons and tons of phones are continually asking "Where am I? Where am I?"

Finally, the triangulation must be accurate to within 164-984 feet (50-300 meters). GPS is significantly more accurate--my bike GPS is accurate to within less than 50 feet. With U-TDOA, accuracy is dependent upon the number of cell towers receiving the data, noise, and the time necessary to crunch the numbers.

So this could be useful for a query like, "I'm in a Seafood mood. What's close?" and not getting a list of Seafood restaurants that are 100 miles away. For directions, because of the accuracy issues, It's initial directions would probably be kind of funky ("You're somewhere around 2nd Street, but you might be beyond 2nd Street. So go down to 3rd Street and turn left, go one block and then turn left until you reach 2nd Street, then turn right and continue along 2nd Street..."). I don't know if you'd want to use it "live" (Or if AT&T would want you to use it "live") because of battery or network issues. However, supposedly the iPhone has 5 hours of talk time, so maybe it wouldn't be too bad.

But, then, I'm not an expert on cellular networks...

June 6, 2007 12:34 PM
dggraphics said:

you can send SMS and email to a fax machine. : )

June 6, 2007 1:13 PM
Ward Author Profile Page said:

That's one thing I can count on from this site: common sense. So rare...

I tried out a location finding system for my blackberry recently. It was off by about five miles.

June 6, 2007 1:13 PM
Dave-O said:

I had a friend that changed to a family plan with his provider (same provider, different plan). He had to buy a new phone because his didn't support E911. This is a requirement and for that reason the iPhone has to know its position.

It does not, however, have to broadcast anything. GPS receivers receive. Obviously for wifi/bluetooth/cell communications the iPhone is broadcasting signals and therefore requires an FCC license. To my knowledge, the FCC doesn't care about receiving signals.

June 6, 2007 1:16 PM
Jack said:

hey, I heard the iPhone has GPS and a version of iChat that makes VOIP calls.

Sorry.

June 6, 2007 1:56 PM

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