Voice Quality on Smart Phones Still Sucks (2014) • Hacker News Board

Re: Voice Quality on Smart Phones Still Sucks (2014)

#41

Post by solotronics » Mon, Dec 07, 2015, 9:26 PM UTC

pak wrote: post #27

jfountain2015 wrote: post #3

Cell quality of GSM/CDMA or others isn't good but the article ignores all the Wi-fi calling, FaceTime Audio and VOIP type calls you can make on a smart phone now. I've found that those are substantially better quality than any landline or cell.

If you want to know the real reason for this, it's because normal cell calls still have to go over POTS ( https://en.wikipedia.org/wiki/Plain_old_telephone_service ) on the backend, which typically uses 8-bit mu-law companding of audio at 8kHz. This compresses the typical frequency range for phone calls to 300-3000Hz, which is a lot smaller than the real range of human hearing, although it covers the range used by hu…

I deal with a ton of cell towers interconnected with Ethernet over fiber [ Ethernet point to point built on MPLS ]. I am not sure about cell towers over POTS but I dont think thats how its done now.

Thats not to say there arent legacy towers out there on POTS, but all new towers are on Ethernet via fiber as far as I can tell.

Re: Voice Quality on Smart Phones Still Sucks (2014)

#42

Post by smileysteve » Mon, Dec 07, 2015, 9:28 PM UTC

dswiese wrote: post #24

but does the average customer care? similar to how Pono may have better audio quality, most people are just fine with a compressed mp3. Its what works and its just good enough.

> but does the average customer care?

They do, but they don't understand why it's bad. This is 'can you hear me now' and 'what'd you say' happen most of the time

Re: Voice Quality on Smart Phones Still Sucks (2014)

#43

Post by pak » Mon, Dec 07, 2015, 11:19 PM UTC

solotronics wrote: post #41

pak wrote: post #27

Earlier quoted context omitted.

If you want to know the real reason for this, it's because normal cell calls still have to go over POTS ( https://en.wikipedia.org/wiki/Plain_old_telephone_service ) on the backend, which typically uses 8-bit mu-law companding of audio at 8kHz. This compresses the typical frequency range for phone calls to 300-3000Hz, which is a lot smaller than the real range of human hearing, although it covers the range used by hu…

I deal with a ton of cell towers interconnected with Ethernet over fiber [ Ethernet point to point built on MPLS ]. I am not sure about cell towers over POTS but I dont think thats how its done now. Thats not to say there arent legacy towers out there on POTS, but all new towers are on Ethernet via fiber as far as I can tell.

Sure, you can connect the towers to the carrier however you want, and this is why certain carriers can sometimes hack in better quality protocols within-network (see the discussion on voLTE further down the page). Carrier-to-carrier connections, however, still have to use POTS/PSTN (since, if you send a voice call to another carrier's network, you can't a priori know it's a smartphone vs. a landline vs. something else right now, and PSTN is the only standard they all agree on). I agree, it's dumb.

Also see https://en.wikipedia.org/wiki/Public_switched_telephone_netw... regarding the 64kbit/s limitation.

Re: Voice Quality on Smart Phones Still Sucks (2014)

#44

Post by cptskippy » Tue, Dec 08, 2015, 12:19 AM UTC

tschuy wrote: post #37

cptskippy wrote: post #22

I started playing around with a Lumia 530 on T-Mobile which has HD Voice and the call quality is night and day compared to my Nexus 4. Everyone I've talked to says the calls sound dramatically better and I'm not aware of anyone who has HD Voice capable phones. The noise cancelling seems to be a big thing as most people tell me that they can't tell I'm driving when I have them on speaker phone. I didn't realize it had…

The Nexus 4 also has HD voice, at least on T-Mobile.

I seriously question your claim and would require some citation. The Nexus 4 call quality is abysmal and the dual microphones to cancel out background noise seem to only amplify it. It's not just my phone because I've had 2 now, I love the phone but it's call quality sucks.

Re: Voice Quality on Smart Phones Still Sucks (2014)

#45

Post by toomuchtodo » Tue, Dec 08, 2015, 2:55 AM UTC

hueving wrote: post #18

guelo wrote: post #16

Earlier quoted context omitted.

None of those IP voice services interoperate either, it's the same issue just at another layer with a different set of greedy corporations.

True, but it's easy to switch between these upper-level services. It's a pain to change cell providers (in the US).

> It's a pain to change cell providers (in the US).

What!? You can port your number from one carrier to another with ease, for several years now.

Re: Voice Quality on Smart Phones Still Sucks (2014)

#46

Post by superuser2 » Tue, Dec 08, 2015, 5:27 AM UTC

pak wrote: post #27

jfountain2015 wrote: post #3

Cell quality of GSM/CDMA or others isn't good but the article ignores all the Wi-fi calling, FaceTime Audio and VOIP type calls you can make on a smart phone now. I've found that those are substantially better quality than any landline or cell.

If you want to know the real reason for this, it's because normal cell calls still have to go over POTS ( https://en.wikipedia.org/wiki/Plain_old_telephone_service ) on the backend, which typically uses 8-bit mu-law companding of audio at 8kHz. This compresses the typical frequency range for phone calls to 300-3000Hz, which is a lot smaller than the real range of human hearing, although it covers the range used by hu…

I've usually found POTS-to-POTS calls to sound much better than latest-iPhone to latest-iPhone telephone calls. Why can't cells at least get to that level?

Re: Voice Quality on Smart Phones Still Sucks (2014)

#47

Post by tumba » Wed, Dec 09, 2015, 2:17 PM UTC

Aloha wrote: post #33

rcthompson wrote: post #28

Earlier quoted context omitted.

That doesn't really explain why smartphones (and cell phones in general) sound so much worse than landlines, does it?

Compression largely, EVRC and GSM (CDMA and GSM respectively) are pretty heavily compressed, while I prefer the sound of EVRC, both are compressed - another thing to point out is most smartphones are pretty lousy telephones, bad earpieces, poor microphones, and so on. If you want to see how cellular handset can perform, use a good communications grade handset.

Any recommendations or examples of "good communications grade" handsets?