The iPhone 5 Review
by Anand Lal Shimpi, Brian Klug & Vivek Gowri on October 16, 2012 11:33 AM EST- Posted in
- Smartphones
- Apple
- Mobile
- iPhone 5
GNSS: Subtle Improvements
Section by Brian Klug
Like the iPhone 4S and the iPhone 4 CDMA before it, Apple has gone with the GNSS (Global Navigation Satellite System) leveraging both GPS and Russian GLONASS which lives entirely on the Qualcomm baseband. In the case of the iPhone 4S and 4 CDMA, that was onboard MDM6610 and MDM6600 respectively, both of which implemented Qualcomm’s gpsOneGen 8 with GLONASS tier. Going to on-baseband GNSS is really the way of the future, and partially the reason why so many of the WLAN, BT, and FM combos don’t include any GNSS themselves (those partners know it as well). In this scheme GNSS simply uses a dedicated port on the transceiver for downconversion, additional filtering (on RTR8600), and then processing on the baseband. The advantage of doing it all here is that often it eliminates the need for another dedicated antenna for GNSS, and also all of the assist and seed information traditionally needed to speed up getting a GPS fix already exists basically for free on the baseband. We’re talking about both a basic location seed, precision clock data, in addition to ephemeris. In effect with all this already existing on the baseband, every GPS start is like a hot start.
There was a considerable bump in both tracking accuracy and time to an assisted GPS fix from the iPhone 4 which used a monolithic GPS receiver to the 4 CDMA and 4S MDM66x0 solution. I made a video last time showing just how dramatic that difference is even in filtered applications like Maps.app. GLONASS isn’t used all the time, but rather when GPS SNR is either low or the accuracy of the resulting fix is poor, or during initial lock.
With MDM9615 now being the baseband inside iPhone 5, not a whole lot changes when it comes to GNSS. MDM9615 implements gpsOneGen 8A instead of just 8, and I dug around to figure out what all has changed in this version. In version 8A Qualcomm has lowered power consumption and increased LTE coexistence with GPS and GLONASS, but otherwise functionality remains the same. MDM9x25 will bring about gpsOneGen 8B with GLONASS, but there aren’t any details about what changes in that particular bump.
I spent a lot of time playing with the iPhone 5 GNSS to make sure there aren’t any issues, and although iOS doesn’t expose direct NMEA data, things look to be implemented perfectly. Getting good location data is now even more important given Apple’s first party turn by turn maps solution. Thankfully fix times are fast, and getting a good fix even indoors with just a roof between you and clear sky is still totally possible.
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rarson - Wednesday, October 17, 2012 - link
Car bumpers are not made of aluminum.Aluminum oxidizes. So if you scratch it, then you've removed that oxidation layer to allow it to further oxidize at that spot. Rust is just iron oxidation.
Spunjji - Friday, October 19, 2012 - link
It is not normal for them to scratch so damn easily. Furthermore, you might notice that other manufacturers (say, HTC?) take steps to harden the surfaces of their devices to avoid this kind of problem.name99 - Wednesday, October 17, 2012 - link
So you're basically(a) upset that Apple fans buy products based on how they look
(b) upset that Apple fans's don't care enough about how products look to care about this
???
The true sign of the demented mind --- that it can happily hold two contradictory opinions at once.
steven75 - Wednesday, October 17, 2012 - link
Would you buy a car that gets nicks and scratches from normal usage?Um yes, everyone does. I guess all cars should be recalled!
Spunjji - Friday, October 19, 2012 - link
Would you buy a car that gets nicks and scratches from simply driving down the street? No, you wouldn't. Stop distorting the argument for an easy victory, it makes for extremely aggravating reading.doobydoo - Saturday, October 20, 2012 - link
And what evidence do you have that the equivalent of 'driving down the street' with an iPhone causes scratching?ltcommanderdata - Tuesday, October 16, 2012 - link
Any final MHz rating on the GPU? Given Apple tends to use a 4:1 clock speed ratio between the CPU and GPU, the SGX543MP3 being up to 325MHz would make sense. The SGX543MP2 seemed to be clocked at 200MHz in the iPhone 4S and 250MHz in the iPad 2 and Apple said the iPad 2012 has a 2x faster GPU, so the SGX543MP4 in the A5X likely is also at 250MHz. A SGX543MP3 at 325MHz vs a SGX543MP4 at 250MHz would seem to explain the results seen in the benchmarks.A few corrections, on page 11 the GLBenchmark 2.5 - Triangle Texture Test - Fragment Lit (Offscreen 180p) is missing the iPad 2012 result.
In iPhone 5 Device Conclusions on page 22, you write "Going back to the old 4:3 aspect ratio iPhones feels extremely claustrophobic now", but it should be 3:2.
daar - Tuesday, October 16, 2012 - link
The in-depth tech info was nice, but would have preferred it in a second post. As an engineer, while I can appreciate the advances made with the new SoC and the depth of the effort went into researching all the aspects of the phone, I also think for most purposes, the length is counterproductive when the majority of readers are looking for indicators of whether the phone is worth an upgrade. Even without the tech explanation though, the review unnaturally lacked the concise detail I'm used to at AT.In some ways, it sort of came across that the tech explanation was a long worded way of making excuses for the iPhone 5's faults and direct comparisons to superior implementations were ignored. Simple example would be the camera, where praise was given about how they cut the size, that it looked good, explanation of the purple tint and so forth. If say, Samsung had released a phone with such issues, I'd expect the review to mention the sloppiness of it, esp with rivals such as the One X having a 2.0f lens (I quite enjoyed the One X/SG3 review comparison from AT). The excuse that the lack of innovation in the new iOS being that the aim of the phone is like that of an appliance whereas Android phones aiming to be PC's is baffling; the concept of a smartphone was a versatile device to aid in our daily lives not reach a point of some ambiguity called an appliance.
darwinosx - Tuesday, October 16, 2012 - link
That was a lot of words to say nothing besides bragging that you are an engineer. Nobody cares.kyuu - Tuesday, October 16, 2012 - link
What nobody cares about are your rabid attacks on any comment that has even the slightest critique of an Apple product.