Verizon, Sprint won't support simultaneous voice/data in iPhone 5

AT&T retains advantage in this area for new smartphone
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Apple's (NASDAQ:AAPL) iPhone 5 will not support simultaneous voice and data transmissions for CDMA customers on Verizon Wireless (NYSE:VZ) and Sprint Nextel (NYSE:S), but will do so for AT&T Mobility (NYSE:T) customers, according to Apple and the carriers.

AT&T iPhone customers have always had the ability to use cellular voice and data at the same time, and AT&T will continue to retain to that advantage over its competitors.

"iPhone 5 supports simultaneous voice and data on GSM-based 3G and LTE networks," Apple spokeswoman Natalie Kerris told the New York Times. "It is not yet possible to do simultaneous voice and data on networks that use CDMA for voice and LTE for data in a single radio design."

"The iPhone 5 is designed to allow customers to make voice calls on the Verizon Wireless network and surf the Web on Wi-Fi," Verizon spokeswoman Brenda Raney said in a statement distributed to media outlets. "It was an Apple decision." Sprint confirmed to The Verge that its iPhone 5 will not support simultaneous voice and data and AT&T confirmed its iPhone 5 will.

What is the main reason behind the split? CDMA networks have always been unable to produce simultaneous voice and data transmissions, but some new LTE smartphones, such as Samsung Electronics' Galaxy S III for Verizon, can do so. Anand Shimpi, editor-in-chief of AnandTech, told the NYT that Apple did not add in a third antenna to the iPhone, which would have allowed its CDMA iPhones to support simultaneous voice and data. Additionally, with the introduction of Voice over LTE technology in the next few years, the issue may become less relevant.

In other iPhone 5 specification news, Sprint confirmed to PhoneScoop that the iPhone 5 will not support its HD Voice solution, which it is implementing as part of its Network Vision network modernization plan. As PC Magazine explained, Sprint is using a new codec called EVRC-NW over its CDMA 1x Advanced network to produce its HD Voice service, and the iPhone 5 does not support that.

Meanwhile, in a bit of intriguing news for AT&T's iPhone 5, the device will apparently have support for more LTE bands than what Apple listed on its website. The GSM variant for AT&T will support AT&T's 700 MHz B Block as well as its AWS Band 4 (2100/1700 MHz), but according to FCC documents unearthed by ExtremeTech, the AT&T device also supports LTE in the 1900 MHz PCS band and the cellular band at 800/850 MHz.

AT&T has said it will turn off its 2G service in those bands over the next few years and could presumably turn on LTE service there, but it is not clear if AT&T requested that Apple add support for those bands. An AT&T spokeswoman declined to comment.

For more:
- see this NYT article
- see this The Verge article
- see this PC Magazine article
- see this GigaOM article
- see this ExtremeTech article

Special Report: Apple's iPhone 5: Complete coverage

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