Comment by chriswarbo | Hacker News Reader

Comment by chriswarbo | Hacker News Reader

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.

> The author invokes the old myth that "digital audio must be sampled, therefore it's lower quality"

Actually, the author made a different argument: That the removal of the higher frequencies in PTSN PCM combined with the low frequency of modern cellphone background noise made for something much harder to understand. As someone quite familiar with the subject, I think this is a very nuanced and compelling argument.

> Saying that the digital protocol is "permanent" is basically a lie;

The author also did a spectacular job dealing with this in an understandable way too, talking about how it's baked into so much of the infrastructure.

> Actually, the author made a different argument: That the removal of the higher frequencies in PTSN PCM combined with the low frequency of modern cellphone background noise made for something much harder to understand.

The author certainly made the case you say, which I don't disagree with. However, they also invoke the "analogue sounds better" myth. Regarding analogue:

> At first, telephone audio was entirely analogue, such that the signal of your voice and your interlocutor’s would be sent directly over the copper wire. The human ear can hear frequencies up to about 20 kHz, but for bandwidth considerations, the channel was restricted to a narrow frequency range called the voice band, between 300 and 3,400 Hz. It was a reasonable choice when the purpose of phones—to transmit and receive normal human speech—was taken into account.

Regarding digital:

> In order to digitally switch calls, the PSTN became subject to sampling, the process of converting a continuous signal to a discrete one... Since the voice band required only 4 kHz of bandwidth, a sampling rate of 8 kHz (that is, 8,000 samples per second) was established by Bell Labs engineers for a voice digitization method.

This choice of frequency is later criticised as too narrow; yet the analogue signal was even narrower! Even ignoring the issues of error correction, etc. this goes completely against the author's claim that "they’ve become much crappier phones... partly because of the nature of the apparatus we used to refer to as the "telephone"...".

>> Saying that the digital protocol is "permanent" is basically a lie; [...it is far easier to upgrade... than the analogue protocols the author is implicitly comparing to.] > > The author also did a spectacular job dealing with this in an understandable way too, talking about how it's baked into so much of the infrastructure.

I've added a little more context to that quote: the existing digital infrastructure may be difficult to upgrade, but the previous analogue networks would be harder. Hence it's misleading to make claims like this when arguing that modern phones are "much crappier" than what came before.

In fact, I disagree that digital phone infrastructure is difficult to upgrade. With a few taps on a digital phone (e.g. running Android) a non-technical user can download a program like Skype, over their digital phone network, install it and be making calls over that network in a matter of minutes. A more technical user can use WebRTC to tunnel any protocols they like, at whatever bandwidth they like, recorded with whichever equipment they like, in whatever location they like, all on top of the existing infrastructure. Those are digital phone calls just as much as any standards-body-approved, nationally-implemented, monopoly-owned operator's offerings.

Also, the author doesn't realize (or maybe never noticed?) that modern handsets support wideband codecs, often marketed as "HD Voice," that offer far superior audio than any landline.

On the other hand, there seems to be little interoperability between carriers, at least in the US. Even though all of the major networks support it between their own customers, none of them enable it between carriers.

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