The Global mobile Suppliers Association notes that 32 commercial LTE1800 systems around the world have been launched, with another 20 in deployment. It is likely that the A1429 (CDMA and GSM) models may actually roam on quite a few networks; however, I'm quite worried about the Model A1428 (GSM) - the US AT&T version, as it does not support the LTE1800 band. This could ultimately influence AT&T's uptake of the iPhone 5 among world travellers. I don't understand why LTE1800 was not supported. For that matter, the LTE 2600 band is also missing from these models - another common worldwide LTE frequency band.
Certainly, some work will need to be done to map out all of the roaming compatibilities and something that I expect we will be doing in the coming weeks as well. Because it does depend on operator supported bands as well as, bands supported on the handset. LTE is highly fragmented across the world when it comes to frequencies.
Still this device will help sow the seeds for LTE roaming and, as it has done for many features, will act as a catalyst for operators to move ahead with their LTE roaming plans - especially those that support the most popular, worldwide LTE frequency band.
Another area that is not really addressed with iPhone 5 is Voice over LTE (or VoLTE). VoLTE needs network support, and today only a couple of Korean operators and metroPCS in the US support VoLTE. Others, such as Verizon are talking about deploying it soon. So, next week, when iPhone 5 hits the streets, LTE will not be used for voice - at least until there is more widespread network support. But, VoLTE support might be something that could be updated in a software revision, later on. For now, the iPhone 5 will likely use circuit-switch fallback for voice.
Like other iPhone generations before, iPhone 5′s features are implemented exceptionally well, and I believe their conservative approach to LTE integration will be likely the best way forward.
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