How Portability Ruined the Telephone (2015)

We can't have sidetone nor full duplex in wide area cellular telephony because end-to-end latencies become so long the far-end echos go beyond asthetically disconcerting.

Try this just for fun: Call someone right next to you via your cell phones and talk to each other. One finds one can speak several words, maybe even a short but complete sentence before the other person starts hearing any of it. It can become a laughably long latency when experienced so directly.

But this cumulative latency ( be it from queuing delays, voice packet grouping for burst transmission, buffering delays along the many packet switches from here to there, you name it ) comprise engineering trade-offs necessary for optimal radio-level multiple access, efficient packetizing, and economically efficient (packet) transmission.

In other words, I'd postulate we can't (today) afford full duplex, sidetone-included, wideband (5KHz+) sub-20-millisecond latency in cellular telephony. Cellular is a different thing, but surely it's its own kind of magic.

But consider modern office telephony over Ethernet: I don't know the internals of it, but aesthetically, I find it significantly better than the analog telephony I remember from 40 years ago: The sidetone's there, it's full-duplex, speakerphone functionality is absolutely superb, and subjectively I find it sounds good.

I'd guesstimate a three orders of magnitude latency ratio between LAN-based telephony vs cellular telephony seems to me key to the very different engineering possibilities and compromises necessary in these two very different domains.

tl;dr 1) The choice of digital protocol for PSTN was sub-optimal; 2) landline phones are installed in areas which tend to be quiet and private; 3) the author likes holding a receiver handset, and doesn't consider modern smartphones or earbuds as good replacements.

None of these are really issues.

1) The author invokes the old myth that "digital audio must be sampled, therefore it's lower quality", whilst conveniently ignoring the facts that a) that sampling can be performed to any degree of precision you like and b) those samples can be reproduced exactly at the other end, unlike analogue signals which constantly degrade. Saying that the digital protocol is "permanent" is basically a lie; the fact it's digital, and being consumed by general purpose computers, means it is far easier to upgrade, provide capability-discovery, compress, tunnel through older protocols, etc. than the analogue protocols the author is implicitly comparing to.

2) Mobile phones are mobile. They can be moved to quiet and private locations. The author laments the loss of landline telephones installed in booths, at restaurants, etc. whilst ignoring how much it cost to install and maintain them. If a business/organisation were to spend money on providing customer phone service, it would make more sense to install a cellular repeater than a bank of landlines.

3) Many handsets are available for use with smartphones.

I think the only problems with mobile phones compared to landlines are social. For example, if a landline isn't answered then the owner might be out; if a mobile isn't answered then the owner doesn't like you; if a mobile goes to voicemail faster than normal, then the owner must have pressed the reject button; etc. These just depend on expectations: if you jump through hoops to be available for calls and answer them as quickly as possible, no matter the inconvenience or situation, then you're setting a high bar for yourself. On the other hand, if you only use a phone when it's convenient, and have it switched off or rejecting calls the rest of the time, then nobody can make those social inferences.

"You Can Hear a Pin Drop" - Sprint, 1986

"Can you hear me now?" - Verizon, 2004.

Voice quality ads discontinued - Verizon, 2011.

I reject the use of voice calls (I actually no longer use a phone) because synchronous communications interrupt what you are doing right now, and more importantly because they lack a proof-of-work barrier. Written communications automatically exclude individuals who cannot read and write properly. That is a fantastic time saver, as it keeps your contact list clean. Furthermore, it is trivially easy to implement anti-spam measures, to exclude individuals who still happen to be able to read/write but whose communications are also undesired. Google/gmail even does that automatically. Written communications are merciless in stamping out and excluding the illiterate and other undesired demographics. Therefore, voice calls are not a feature of a phone, but a bug.

I think the author would enjoy one of these:

http://www.instructables.com/id/Adapting-a-Telephone-Handset...

A few thoughts from deep inside the VoIP industry:

1) There are "high definition" / wideband codecs that remove the traditional 3.1 KHz PCM bearer channel audio spectrum restriction, along with its logarithmic companding, such as G.722. There is also desk handset hardware that makes them sound really, really good; given both, it's unlike any phone call you've ever had.

2) The challenge is that even in 2016, the PSTN - with its 3.1 KHz bearer channels - is still the common denominator to which nearly all audio must be reduced. So, you only stand a chance of having that kind of call quality on a private/intra-PBX type call.

3) Direct IP peering among VoIP providers hasn't really taken off, although pure-IP signalling across interconnects is becoming increasingly common. This is largely due to institutional inertia and deliberate lobbying on the part of LECs of all kinds who are invested in the incumbent per-minute revenue models and cost structures of the PSTN. (Even though the measured usage aspect is generally hidden from the end-user, the intra-industrial cost structure is not at all flat-rate.)

4) The VoLTE ambitions of mobile operators might change the game a lot as far as call quality, but there is some question as to whether the spectrum is physically there to support HD calls for all, and of course the limiting factor of mobile handsets as described in the article.

5) Residential and consumer users are probably not willing to pay for premium call quality experiences or value-added application-level features, and the VoIP industry is mostly disinterested in selling to them except through wholesale channels. But core business users - folks who still use desk phones, and who are pretty much the exclusive focus of the VoIP industry at this point - do care about this, and there's active work going on to cater to them and make their conference calls and such sound better.

6) WebRTC is overhyped and overrated, but there is one large industry to which it is directly relevant and for which it will make a significant impact: contact centres (call centres, customer service centres, support centres, etc.). Better codecs can be found there also, though somewhat offset by the varying quality of Internet connectivity and intermediate network engineering (that call centres are cheapscates is an understatement).

7) Along the lines of #4, over-the-top applications that support voice calling, such as Skype and WhatsApp, are also increasingly changing the character of the typical Millennial's "phone call", especially outside the USA. However, they are aggressively resisted by mobile carriers for obvious reasons: it commoditises them down into a dumb data pipe and purely price-level competition to provide bandwidth, while some clever Silicon Valley app takes all the value-added / higher-margin premium.