LTE and the iPad
louie at transsys.com
Wed May 2 16:05:56 CDT 2012
On May 2, 2012, at 4:47 PM, Andre Kesteloot wrote:
> André N4ICK
> Tacos mailing list
> Tacos at amrad.org
This is hardly surprising.
With increasing demand for new wireless capacity, new bands have been allocated for use in mobile networks, and different spectrum is freed up in different countries as time goes on. It's driven somewhat by the ability to migrate existing spectrum users out of this new mobile spectrum allocation.
The other thing to note is that most operators deploy LTE in new spectrum allocations. The demand is for data carriage, not for handling more voice calls. So they can opportunistically roll out LTE in new bands in markets that have capacity issues. And the new devices with the bigger screens that will typically use more bandwidth than the 3 year old phone.
It's a real tough engineering challenge to build a truly universal LTE radio. Not only do you have the choice to support the 43 different LTE operating bands that have been standardized, there's also a choice the operator can make to deploy FDD (full duplex, with distinct uplink/downlink bands) or TDD (single frequency ping-pong). http://en.wikipedia.org/wiki/E-UTRA#Frequency_bands_and_channel_bandwidths for details.
The other funny bit is that I don't think anyone has deployed any carrier voice services on LTE yet. The standards bodies have only recently finished the definitions for how this is supposed to work. In LTE, voice will be carried as VoIP as another data application, but it's way more complicated than that to support handing-off the call between 2G, 3G and 4G LTE networks. Oh, and you have CDMA and GSM based signaling protocols to worry about as well when figuring out the handoff problem. It's a bit easier to deploy a data-only LTE service at the outset.
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