Apple Inc.'s Let's talk iPhone event on Tuesday offered something which is not just enough to satisfy the feature-hungry iPhone fans. Saying 'yes' to the rumors of a thorough revised model of last year's iPhone 4, the company unveiled iPhone 4S, and the iPhone 5 mystery remained a mystery after all.

But what could be the reason behind the move, which is considered by many as a setback? According to an analyst, the Cupertino-based tech giant is preparing a phone branded as the iPhone 5, which will sport 4G LTE technology.

Analyst Will Strauss, president of wireless chip market research firm Forward Concepts, told CNET that Apple is saving the iPhone 5 brand for the LTE version, and the new model won't arrive until the 4G LTE technology is ready to be used in smartphones.

They're saving iPhone 5 for the LTE version and that won't be out until next spring, said Strauss. Compared to existing 3G technology, LTE provides higher download and upload speeds, among other key features.

Strauss, who tracks companies such as Qualcomm that deliver the chips for 3G and 4G technology for smartphones, also said that Apple cannot come out with LTE now. According to him, for Apple's taste, the current implementations of LTE technology in phones like the HTC Thunderbolt are too kludgy, CNET reported.

There are two chip solutions in LTE-capable HTC Thunderbolt - an LTE baseband (modem) chip and a second one from Qualcomm for 3G voice connections, Strauss said.

In addition, there were reports that Apple was unhappy with the first generation LTE chipsets from Qualcomm that would make phones bulkier. In April, Apple's then stand-in Chief Executive Officer (CEO), Tim Cook, said that the first generation LTE chipsets forced a lot of design compromises with the handset and that the company was not willing to make those compromises.

According to another analyst Anand Shimpi, chip expert and CEO of Anandtech, the iPhone 4 printed circuit board is not big enough to carry an extra chip to enable LTE without shrinking the size of the battery. He said that a Qualcomm chip called the MDM9615, which will be capable of LTE voice and data that would fit Apple's phone specifications, is likely to come out in the second quarter of 2012.

Apple (and all other smartphone makers) could [use]...the MDM9615 and have a 'single chip' LTE solution for smartphones...Next year (Q2 to be exact) should be when we can finally get LTE into something iPhone-sized, Anand wrote.

Anand believes the reason that has caught a number of handset makers by surprise is the stumbling blocks in the jump from 4x-nm to 28nm chips.

I suspect that an aggressive 28nm roadmap that didn't pan out probably caught a lot of SoC and smartphone vendors in a position where they couldn't ship what they wanted to in 2011, Anand wrote. If I were to guess at the release date of the rumored iPhone 5 I'd say early Q3 2012.

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