Most of the “conventional wisdom” currently going around is that Apple has lock, stock and barrel moved to the Qualcomm baseband (RF – the cellular part) processor for all future iPhones. If that does turn out to be the case, then you can just ignore the rest of this post.
However I’m inclined to believe Apple may not yet unify the GSM and CDMA iPhones, especially given the size footprint of the Qualcomm CDMA/EVDO/HSPA+ chipset inside the iPhone 4 (CDMA). Without a significant redesign Apple just cant put all those chips necessary for a dual-mode phone, plus the Micro-SIM slot, plus the Qualcomm chip inside on that tiny PCB. Given recent rumors, the next iPhone isn’t expected to be a big overhaul.Anandtech was smart to point out the space limitation…
Though the baseband supports dual mode operation, upon looking at more of the CDMA iPhone disassembled, it’s quickly apparent why that isn’t put into use. There simply isn’t space for the required power amps as the mainboard is organized right now. Though there’s definitely space picked up from losing the SIM slot (which, as an aside, explains why Apple seemed keen on losing SIMs entirely – it’s starting to become a huge chunk of real-estate), but the MDM6600 is simply larger than the Infineon X-Gold 618. Unless you can get in there and add both the signaling for the SIM and necessary RF components, there’s no way the CDMA iPhone is becoming dual-mode anytime soon.
To make a dual-mode phone that would work on both AT&T and Verizon, you’d need 3 more RF amps, a 10-way switch, and numerous other parts (along with paying for both CDMA and GSM/HSPA licensing fees to the respective patent owners for every phone, an extra cost of up to $20/unit). While keeping the phones separate means paying less money to patent holders for technology the user may never use (how often would an AT&T customer use the CDMA parts of the phone – I cant think of any exclusively CDMA countries, even South Korea has a 3G GSM network).
So in comes Intel’s (neé Infineon), the provider of the RF baseband chips in the iPhone, 3G, 3GS and 4-GSM models with a new 3G/HSPA+ RF baseband chip. The specifications are impressive – 21Mb/s down and 11.5Mb/s up, which translates roughly to 5-6Mb/s down and 2.5Mb/s up in the real world on a good network. But more importantly there are two features Intel is really pushing about the chip that make this seem to be custom tailored for Apple.
First is the power efficiency. The previous chip (in the 4-GSM model phones) was built at 65nm, and the new chip is 40nm. To those that understand semiconductor fabrication technology know those numbers mean a huge leap in terms of power consumption – for the same workload the new chip may consume as much as 65% less powerthan the previous generation chip, since the fabrication technology has gone down 1.5 “nodes”. This is something Apple, in their never ending quest for battery life and usability, could benefit tremendously from. I’d estimate it buys an extra 30% on 3G talk time, and 15% on 3G web, bringing Apple’s stated totals to 9 hrs 3G talk and 7 hrs 3G web.
Second is the package size. Intel is pushing hard that the chip’s footprint is very small, which is appropriate for Apple’s notoriously small circuit boards. The goal to make the chip small allows Apple to make the circuit board smaller, and make the battery larger (or just the same volume, just thinner). Making the package smaller could also accommodate larger/alternate amps and radios, to possibly accommodate other GSM bands (perhaps even T-Mobile’s AWS band?).
Anyways, just some wishful speculation. To me its always made sense that Apple not unify their product line at the iPhone 5 from a cost perspective. We’ll see the first unified phones when we move to LTE in 2012, and if Apple can get their way, no more SIM card either.