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الاثنين، 31 ديسمبر 2012



happy new year 2013




الأحد، 30 ديسمبر 2012

Why Apple Made Three iPhone 5 Models and What That Means For You


Apple has finally made its latest iPhone compatible with LTE networks. But it’s not all good news for the company’s customers. Due to 4G LTE fragmentation, Apple has had to make three different models of the iPhone 5. Where the iPhone 4S was a dual GSM/CDMA device, meaning one model for all carriers, the LTE-enabled iPhone 5 comes in two separate GSM models and one CDMA model. This means that consumers will have fewer choices when switching carriers, and that LTE access will be limited when traveling abroad

Since carriers utilize different radio frequencies (also known as frequency bands) for LTE service, Apple has had to diversify its iPhone 5 portfolio. This largely has to do with the fact that 4G LTE is still in the early stages of development, compared to more mature networks like 2G and 3G. It’s a messy situation that Android handset makers like Samsung and HTC have been dealing with when it comes to their 4G LTE devices. For example, the Samsung Galaxy SIII comes in nine model variants, five of which are specific to North American carriers.

The three iPhone 5 models include: GSM model A1428 that supports LTE Bands 4 and 17; GSM model A1429 that supports LTE Bands 1, 3, and 5; and CDMA model A1429 that supports LTE Bands 1, 3, 5, 13, and 25

In layman’s terms, this means an iPhone 5 user who wanted to jump from, say, AT&T to Verizon or vice versa, would have to buy a new handset, since AT&T runs a GSM network and Verizon is CDMA. And where owners of GSM handsets previously enjoyed wide compatibility with foreign networks, LTE fragmentation means that AT&T customers using an iPhone 5 in Europe, for example, won’t be able to take advantage of LTE speeds while abroad and will instead get kicked down to the 3G network.


“With 2G, pretty much everything has matured to use four main frequency bands,” IHS analyst Francis Sideco told Wired. “And the components have matured enough so there are a lot of multiband components out there. 3G is in a similar state, where the bands are known and components are becoming more integrated with multiband capability…. When we get to LTE, neither one of those things is true. The bands that are being selected by operators globally have not coalesced, nor are the components mature enough where they are integrating to the same degree as far as multiband capability.”

The GSM A1428 model appears to be made specifically for AT&T, which is the only carrier that uses both LTE Bands 4 and 17. It will also support T-Mobile’s U.S. LTE network as well as several Canadian networks. But don’t expect any LTE service outside of North America — currently no carriers in other countries use Bands 4 or 17. Even though GSM networks are more common worldwide, this particular iPhone 5 model is not a global phone when it comes to LTE support. Instead, Apple has opted to make a second GSM model for other countries. Model A1429 supports the three more common LTE Bands in places like Asia and Europe, but none for North America use

he CDMA phone, however, is more of a global device. It supports the same three LTE bands as the non-U.S. GSM phone, as well as the two main bands used by U.S. carriers Verizon and Sprint. Another benefit to the CDMA phone is that it supports GSM/EDGE radio frequencies, while the GSM phones do not support CDMA frequencies. GSM support is available for both international and domestic use; just keep in mind that if you switch your CDMA phone to a GSM network like AT&T, you likely won’t get LTE access. What is oddly missing from all three phones is LTE support for a large portion of Western Europe, which uses LTE Band 7

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When asked why Apple chose to make two GSM phones, instead of one that could work globally with LTE networks, Sideco pointed to the bands each of the phones supports. It could be that there are no multiband components for AT&T frequencies (Bands 4 and 17), while there were for Verizon and Sprint’s LTE networks. We won’t, however, know for sure until we get a peek inside the iPhone 5 models

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After we’ve done a teardown and know exactly which companies have been used for the different models, we’ll actually be able to provide more insight to what might have driven these decisions,” Sideco said. “It could come from many different factors.”

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