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Has the GPS chip been upgraded in the iPhone 4S? How does it compare to the 4 and 3GS?

As I understand it the GPS in iPhone 4 is much better than that in the 3GS.

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closed as not a real question by Loïc Wolff, bmike, cksum, Philip Regan Oct 14 '11 at 18:00

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I presume that you are asking because you require or would at least enjoy more accurate reception. Frankly though, the chip used has little to do with the relative accuracy when compared to the role that the antennas have. Accuracy could be much improved even with the same chip, and also it could be slightly degraded if the antenna designs have focussed on the other spectrums for 3G etc. I would expect that it would be better simple because time yields improvements, but without headline grabbing multiple and/or WAAS antennas I doubt there will be much in it from a user perspective. –  stuffe Oct 11 '11 at 15:04
    
@stuffe Okay, thank you! –  Znarkus Oct 11 '11 at 16:36
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Honest question... how can GPS possibly be more or less accurate? GPS provides has a specific level of granularity, and I was under the impression that any GPS receiver receives and uses the same amount of granularity. –  Jason Salaz Oct 11 '11 at 19:24
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The GPS signal, all things being equal in clear reception areas, should be constant regardless of the device you use. All the GPS signal is, though, is a stream of data broadcast at something ridiculous like 50bytes a second which contains the current timestamp, that is synchronised with all the satellites than sit in geosynchronous orbit (i.e. they never move their relative position to Earth, and are always located in the same place). None of this provides any location data whatsoever. Location data is calculated by getting the GPS stream from at least 3 satellites, and using trigonometry –  stuffe Oct 12 '11 at 9:01
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...your device does the calculating. If the timestamp from satellite A is 2 seconds old, and the one from B is 1.8 seconds old, and the one from C is 1.9 seconds old by the time they arrive on the device and can be compared, then it can triangulate your position using that data. –  stuffe Oct 12 '11 at 9:03
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3 Answers 3

up vote 1 down vote accepted

Just got the iPhone 4S - GPS reception is much better then iPhone 4.

I checked number of satellites the phone can see - using MotionX GPS app, same location, same time. The two phones was next to each other for 15 minutes, and I also swapped their location few times.

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What, didn't know they'd even shipped them yet. If so, very good. Thank you! –  Znarkus Oct 14 '11 at 18:41
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The iPhone 4s, and the most recent iPhone 4 (Verizon) don't use a discrete GPS chip, as it's integrated into the baseband (Qualcomm MDM 6600). I believe the GPS chip in the iPhone 3GS used the Hammerhead II PMB 2540, or 2525 GPS chip. By integrating the GPS with the baseband it allows a smaller phone, less energy consumption, and cost less to produce.

iPhone 4s GPS [Qualcomm MDM 6600 Gobi]

The main improvements should be:

  • Integration with Siri
  • Updated antenna switching (spatial diversity)
  • Improved TTFF and TTSF (fixes)
  • Longer battery life (more energy efficient)
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High quality rumor and speculation - will gladly up vote once we have some tear downs and initial data on how the combined software / hardware stack works in iPhone 4S. The API doesn't give raw GPS data, so the iOS software plays a large role in this even when the underlying tech changes. –  bmike Oct 11 '11 at 14:11
    
Not speculation or rumors; I am only stating facts. Check the Apple website and maybe you will stop jumping to conclusions smarty pants. –  l'L'l Oct 11 '11 at 14:19
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How do you know the antenna switching doesn't intentionally sacrifice GPS accuracy for other concerns? Why say "leads me to think" if you're not speculating :-) your awesome facts seemed to stop at By integrating unless you've seen engineering details or somehow have a phone already and are being coy. I do apologize if I offended you with my comment(s). I like this place for having real documented answers - not opinion pieces or attempts to break the news. –  bmike Oct 11 '11 at 14:28
    
Apples own website lists the improvements I've mentioned. Since you seem to be the expert I'm sure it's a myth that anyone might be using the iOS 5 SDK, or has an iPhone 4s and writes GPS applications for mobile devices too right? Hmmm, well I better get back to work. –  l'L'l Oct 11 '11 at 14:38
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Also, there are such things called non-disclosure agreements. –  l'L'l Oct 11 '11 at 14:44
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Since there is no official iPhone 4S delivered, I think there are no good records about this chip. All I can tell is the GPS accuracy improves with every iPhone model so far. iPhone 3G sucks at GPS, iPhone 3GS was a bit better, iPad 1 was accurate, iPhone 4 is excellent as well as the iPad 2.
So as technology keeps improving, I guess the chips used in Apple's iPhones will too.

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An iFixit teardown showed that the iPad 1 and iPhone 4 has the same GPS, question is if the iPad 1 and 2 have the same GPS chip? –  Znarkus Oct 11 '11 at 15:07
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