What is 3G iPhone anyway?

Wednesday, May 14, 2008

A friend posed this iPhone question recently –

Could the iPhone run on CDMA with the Infineon chip that will be in the 3G GSM phone? Or would different hardware and/or software be required?”

I thought I will publish a tutorial to benefit all my readers. This is my view of the wirelss standard we will see implemented in the 3G iPhone.

There are two pervasive wireless standards that support 3G -

  • The third generation partnership project (3GPP) has defined 3G as the CDMA-based evolution of GSM. So, GSM networks (e.g. AT&T in the US and most of Europe) have migrated or are migrating to WCDMA for higher voice capacity and also nominal data-rates. 3GPP has also added high throughput data capabilities in its later releases of the standard (e.g. HSDPA, HSPA, HSPA+.)
  • The Qualcomm-promoted CDMA2000 1x standard is part of the 3GPP2. Qualcomm calls its CDMA2000 1x as 3G. High throughput data capabilities have been added in the various revisions of EV-DO. Hence EV-DO is considered a natural evolution path for most CDMA2000 1x based networks (e.g. Sprint, Verizon)

Now, if we assume that the iPhone 3G has the Infineon SGOLD3H chip and its HEDGE platform, then we will have -

  • 3GPP Release 5 compliant dual-mode protocol stack
  • HSDPA with up to 7.2 Mbps for downlink
  • WCDMA 384 Kbps for uplink and downlink
  • Backward compatibility with GSM/GPRS/EDGE

For more details, I will direct you to the Infineon product brochure here. This version of iPhone 3G will have support for the above standards and nothing more. Essentially, it will not have HSUPA, or HSPA+.

Further, if the Infineon assumption holds, we will not have one iPhone that supports both 3GPP and 3GPP2-based standards. In other words, if the 3G iPhone is HSDPA capable, it will not be CDMA1x or EV-DO capable. Of course, it does not preclude Apple from releasing two versions of the iPhone – one for HSDPA and the other for CDMA1x/EV-DO. This will necessitate that Apple develop a completely new chipset/platform partnering with Qualcomm.

The common 3G iPhone notion is WCDMA or HSDPA-capability. Though not impossible, Apple will mostly desist from a CDMA1x version now. There are at least two reasons for this

  • WCDMA/HSDPA will be the dominant 3G standard moving forward. This will allow Apple to address most markets
  • In the US, a major market for CDMA1x, AT&T provides enough opportunities for Apple to increase its market share. In turn, the iPhone gives AT&T the chance to steal subscribers from the other service providers

In summary, a software upgrade/hack will not make AT&T’s 3G iPhone CDMA1x/EV-DO capable so you can use on Sprint or Verizon. Finally, irrespective of the actual standard in the 3G iPhone, the truth is it will have a CDMA air interface.

Posted by Vijay Nagarajan at 10:00 PM  



Nice blog and good articles.

I have a question..

If we assume Infineon chipset(or any other vendor's chipset) is used, would that vendor still be paying royalties to Qualcomm?


May 15, 2008 at 4:46 PM  

Yes. The rate is determined by the relative IP positions though.

Please read


for the details.


Vijay Nagarajan said...
May 15, 2008 at 4:59 PM  

I think the link I meant to put on my previous comment got truncated. Please read my Qualcomm and iPhone article for more on the topic of iPhone royalties.


Vijay Nagarajan said...
May 15, 2008 at 5:00 PM  

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