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MeasurementBlues
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Re: How's your LTE performance?
MeasurementBlues   8/20/2013 11:45:44 AM
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I know people who have dial phones at thome on no mobile phones at all.

MeasurementBlues
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Re: How's your LTE performance?
MeasurementBlues   8/20/2013 11:44:05 AM
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#G/4G kills batteries life on an iPhone and costs too much anyway. I keep my phone on 2G rather than run down the battery faster and pay more.

Bert22306
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CEO
Re: Voice over LTE
Bert22306   8/19/2013 6:56:25 PM
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Sticklers will no doubt object to my claim that AM radio is 5 KHz. In the US, the RF channel width is 10 KHz, however AM radio in the AM broadcast band uses double sideband. That makes audio quality limited to 5 KHz in theory, and often no better than 3.6 or so KHz in practical receivers.

Also, during the day, it's possible for AM radio stations to expand their channel width. But in practice that buys you very little. Most AM receivers aren't set up to use the wider band. And at dusk, all of that goes out the window anyway.

Bert22306
User Rank
CEO
Re: Voice over LTE
Bert22306   8/19/2013 6:45:58 PM
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As one who finds all voice telephony quality to be pathetic, whether land line or cellular, analog or digital, I'm also interested in seeing drastic improvements. I can only imagine how much more useful teleconferncing would be, if we weren't tied to traditional telephony standards.

From the days of analog telephones, the voice bandwidth was limited to a 4 KHz channel, so that means a practical passband of about 3.3 or perhaps 3.5 KHz. As bad as most AM radio in practice, although worse than AM radio in principle (where channel width is 5 KHz in the US).

That's why voice telephony sounds like the other guy is covering his mouth all the time.

When digital telephony came to be, that 4 KHz channel width was deemed good enough, and the standard 8 KHz sampling rate used in digital telephoney made darned sure that we wouldn't get anything better.

HD voice doubles that passband to 7 KHz. That should improve matters a lot. Although Skype, unhampered by any of this, can sound even much better than HD voice (assuming a decent broadband connection and that both sides have the latest codec).

junko.yoshida
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Blogger
Voice over LTE
junko.yoshida   8/19/2013 2:53:26 PM
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The author of this piece pointed out: 

LTE has been predicated on the promise of high-speed mobile broadband access, but subscribers will still expect to make voice calls on their devices, so audio quality needs to be assured. The success of services like HD voice and voice over LTE (VoLTE) depend on device and network performance, and audio quality performance testing is a critical component of LTE testing.


I am wondering about the differences in voice quality between voice over LTE and voice over 3G. Can anyone give us any pointers? And what about HD voice? How is that different from other voice?

 

rick merritt
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Author
How's your LTE performance?
rick merritt   8/19/2013 1:23:45 PM
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Speaking of real-world LTE performance, it would be cool if folks with handsets would chime in on what benefits they may be seeing, if any over 3G.

JanineLove
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Blogger
LTE-A and real world
JanineLove   8/19/2013 11:10:17 AM
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I'm curious about this statement: "where real-world environments and scenarios are replicated" How ready are we for "real-world" simulation with LTE-A?



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