Voice and SMS over LTE

CS Fallback an LTE Innovation? I don't think so.

I was surprised by the announcement this week that a vendor has “successfully completed a circuit switch fallback voice call”.  

After reading the release, I’m shocked that making a call with CSFB is considered “a breakthrough demonstrating continued innovation in LTE/EPC”.

I’m not sure forcing a phone off LTE and back to GSM when the user wants to make a phone call is really a ‘continued innovation in LTE’.  

Am I the only one that sees CS Fallback as a step backward for the industry?    

It seems to me that a continued innovation would be giving operators the ability to turn their existing voice service into a VoIP service over LTE.  There’s no need to ‘fall back’ for operators to make ‘full use of their existing network to protect investments’.  

VoLGA, the simple solution which was demonstrated by two vendors more than a year ago, turns mobile voice into mobile VoIP.  No complicated interfaces, all proven 3GPP technology.

PS - kudos to James Middleton at Telecoms.com for using the image of the tin cans in his coverage of this 'announcement'.  

Verizon LTE's phones: Still no voice over LTE

I braved the mobs at CES last week.  I managed to squeeze into the Verizon stand for a look at their new LTE phones.  I saw two of the four devices, and both were exactly like you’d expect: Android smartphones with touchscreens. 

I spoke with the Verizon reps to understand how voice services would be delivered. 

But first, a word on CDMA network technology.  Of course Verizon has a CDMA-based network (as opposed to a GSM-based network like 90% of the world).  In CDMA land, 1xRTT is the radio equivalent of ‘2G’ (ie circuit voice).  CDMA operators added data with EV-DO, which is a ‘Data-Only’ 3G-esque technology.  In the GSM world, the 3G technology (W-CDMA) supports voice and data concurrently. 

The point is, Verizon’s entire 3G network is ‘data only’, there is no ability to have simultaneous voice and data.  If you’re on a phone call, you’re on 1xRTT.  If you’re surfing the web, you’re on EV-DO.  If a call comes in, the EV-DO radio stops and the 1xRTT radio starts.  This is a deficiency that AT&T has hammered home several times. 

Back to LTE… 

It turns out, Verizon is going to treat voice the same in LTE as it does in EV-DO. 

LTE = no native voice (use 1xRTT); EV-DO = no native voice (use 1xRTT). 

The rep I spoke with said they are working to come up with a way to have the 1xRTT radio on all the time while the LTE radio was on so there wouldn’t be a delay in making (or receiving calls).

I asked what impact there might be on battery life by having both the LTE and 1xRTT radios on simultaneously.  The rep said that while they are technically building this capability, in all likelihood the phones will ship with simultaneous V&D turned off.  Huh????

Then I asked about IMS… “Way off in the future”.  Great.

There is still no voice over LTE.