Is iDEN's voice quality superior than CDMA?

[MacinJosh]

 

 

Yeah, if that phone has support for 850/1900 GSM but not 850/1900 UMTS, then you're hitting the ancient GSM network put up by Cingular/ATTWS.

 

 

No. It do support UMTS and even HSPA. Not quite sure why verizon allow this to happen. Is it part of their agreement with FCC when they bought 700Mhz?

 

Yep. They have to leave all their LTE devices unlocked. Sucks to be them, lol.

 

 

Sent from Josh's iPhone 5 using Tapatalk 2

[Rawvega]

Yeah sucks for them I guess, but it is a good thing for consumers.

[gusherb]

Here in Austin, VZW voice quality is atrocious. Their codec is mega compressed. They use all 1900 here for CDMA. I'd rather someone not call me at all rather than try to have a phone conversation with them. On top of that, there is terrible lag/delay on the circuit between Sprint and VZW networks.

 

I find the exact same thing here on VZW, except I also noticed that like a micro climate effect, the VQ quality varies from site to site and area to area. Calls going through the site that serves around my house have good VQ, but out by the mall it's horrible. This same pattern repeats from site to site all around the area, in most places it's bad though. VZW is 850-only around here, with very wide site spacing in the suburbs (I hear even in Chicago) VZW is not even the most populated carrier around here, AT&T and Sprint are. 

[WiWavelength]

I find the exact same thing here on VZW, except I also noticed that like a micro climate effect, the VQ quality varies from site to site and area to area.

 

I refuse to give parent company and corporate asshat VZ any money, so I cannot confirm this.  But VZW is reportedly using EVRC-B, which allows the network dynamically to swap voice quality for network capacity.  That could explain your varied experience.

 

AJ

[gusherb]

I refuse to give parent company and corporate asshat VZ any money, so I cannot confirm this.  But VZW is reportedly using EVRC-B, which allows the network dynamically to swap voice quality for network capacity.  That could explain your varied experience.

 

AJ

I tried them out through a Tracfone. 

 

Sprint for as long as I've had my service with them (8 months now) has been using EVRC-B. They apparently use the highest bitrate available in EVRC-B (8.5 kbit/s is it?) 

For about a month the site serving where I live was forcing QCELP13 though, which to me sounds the same as Sprint's EVRC-B except with the annoying scratchiness that comes with the 13k codec. I can't wait for VoLTE or to get a device that supports one of the wideband codecs. I hate talking on cellphones so much that I keep calls short. I use a POTS or VOIP line (with a good quality phone) If I wanna talk to someone for awhile. 

[WiWavelength]

Sprint for as long as I've had my service with them (8 months now) has been using EVRC-B. They apparently use the highest bitrate available in EVRC-B (8.5 kbit/s is it?)

That must be market or vendor dependent, maybe even Chicago (or CDMA1X 800) specific.  In Kansas City, we are definitely still on SO00003, which is good old EVRC.

 

As for bit rates, EVRC adjusts dynamically on a frame by frame basis among full rate, half rate, quarter rate, and eighth rate.  Correct, full rate is 8.55 kbps.  I do not know the nitty gritty details of EVRC-B, but my guess is that it allows the network to limit the number of full rate frames based on capacity needs.  By comparison, EVRC seems to encode basically all speech frames at full rate, falling back to eighth rate during silences -- mostly, bouncing back and forth between full rate and eighth rate.

 

For about a month the site serving where I live was forcing QCELP13 though, which to me sounds the same as Sprint's EVRC-B except with the annoying scratchiness that comes with the 13k codec.

 

Hmm, that was an interesting, temporary glitch.  Roamers on the Sprint network can typically force 13K QCELP, but native Sprint subs have not been able to do so on the Sprint network since roughly 2000-2001 if I recall correctly.

 

AJ

[Fraydog]

Yeah sucks for them I guess, but it is a good thing for consumers.

 

They're fighting like hell to overturn those open access rules in court.

[Rawvega]

They're fighting like hell to overturn those open access rules in court.

 

Well this is VZW that we're talking about so naturally we can't expect for them to like anything that even has a whiff of being pro-consumer.

[userkv8031]

Going back to voice quality here...I have noticed a big difference between my old Moto V950 and a Duramax. The sound quality of the Duramax is very tinny and distorted, even more so when loud. The V950 was clear and seemed to have more of a dynamic range (a bit more of the low range). Even when the V950 was loud it was still clear and had the dynamic range intact. I think Sprint needs to pressure the phone manufacturers to include better speakers on all models of phones.

[gusherb]

That must be market or vendor dependent, maybe even Chicago (or CDMA1X 800) specific.  In Kansas City, we are definitely still on SO00003, which is good old EVRC.

 

As for bit rates, EVRC adjusts dynamically on a frame by frame basis among full rate, half rate, quarter rate, and eighth rate.  Correct, full rate is 8.55 kbps.  I do not know the nitty gritty details of EVRC-B, but my guess is that it allows the network to limit the number of full rate frames based on capacity needs.  By comparison, EVRC seems to encode basically all speech frames at full rate, falling back to eighth rate during silences -- mostly, bouncing back and forth between full rate and eighth rate.

 

 

Hmm, that was an interesting, temporary glitch.  Roamers on the Sprint network can typically force 13K QCELP, but native Sprint subs have not been able to do so on the Sprint network since roughly 2000-2001 if I recall correctly.

 

AJ

 

It must be an anomaly for me, or another market/vendor specific thing, but I'm readily able to Force QCELP13, or even EVRC instead of EVRC-B on my GS3. I do think the stability of voice calls suffered when I was stuck on 13k, when I originally tried it I found that to be the case. Now that it's back to normal I haven't had any bit of choppiness at all. Also during that time that was going on, I was occasionally getting fast busies in the area, and still get what has got to be a bad connection in the PSTN every once in awhile (sounds like horrible distortion & background noise, the same thing happens on my grandma's AT&T POTS line every so often, you fix it by hanging up and dialing again) 

 

Oh I also forgot to mention that EVRC-B applies to 1X800 and 1900, I mentioned this some months ago and someone wanted numbers and I provided them and that turned out to be the case, still is. 

[dnwk]

Yeah sucks for them I guess, but it is a good thing for consumers.

 

Not really. Although it is Unlock, but it is really tricky to get its data working in ATT's network. They purposely make the configure difficult.

[iansltx]

I remember being able to select SMV as the home codec on my HTC Mogul (or was it my Touch Pro?). May have been the placebo effect, but I thought that calls sounded better with that codec selected.

 

As for the iDEN vs. CDMA discussion, I'd go for CDMA, as long as you've got halfway-decent reception and aren't dropping to half/quarter-rate all the time due to capacity concerns. Fortunately, Sprint doesn't seem to do that, so voice quality is decent here.

 

That said, running GrooVeIP on my Nexus 4, either over HSPA or over WiFi, gives significantly better voice quality, albeit with delay and/or echo issues at times. But hey, 64k uncompressed PCM voice, or whatever GVoice is actually using (probably G.711 or whatever) is wonderful.

 

Then there's the AT&T vs. T-Mobile voice quality comparison. AT&T often employs half-rate AMR-NB to squeeze more capacity out of their network. T-Mobile, to my knowledge, is full-rate AMR-NB, or even AMR-WB, everywhere. So if you can get a decent signal with them, they're comparable quality-wise to a CDMA call in ideal conditions.

 

As for GSM buzz, any TDMA airlink around 850MHz will cause harmonics that manifest themselves in speaker interference. In the case of iDEN, I've had CRTs go wobbly due to interference caused by using data or voice on my phone near the monitor. WCDMA/CDMA don't have this issue. LTE 750 actually does have this issue to an extent.

[jsolo]

Could someone clarify, on an android/cdma device, how do I see what vocoder is in use?

 

On my evo 4g lte, the debug screen does not seem to indicate this (##debug#).