Hacker News Reader

Comment by saurik | Hacker News Reader

Landlines were so fast and so "direct" in their latency (where distance correlates very directly with time, due to a lack of "hops") that local phone calls were faster than the speed of sound across a table, and for a bit after they came out--before people generally got used to seemingly random latency--local calls felt "intimate", like as if you were talking to someone in bed with their head right next to you; I also have heard stories of negotiators who had gotten really tuned to analyzing people's wait times while thinking that long distance calls were confusing and threw them off their game. But no: cell phones haven't become as fast as landlines and likely never can due to fundamental contrast of compressed packetized routed audio vs. the speed of an analog signal propagating over a circuit-switched wired connection.

View on HN

I have very clear memories of my first overseas long-distance calls in the 1980s, which were over a satellite link. The latency was so pronounced (about half a second) that carrying out a conversation took quite a bit of practice. You almost had to carry out a formal protocol of handing over control of the line, as if you were on a walkie-talkie.

I have equally clear memories of my first overseas calls carried by undersea fiber because the lack of latency was so pronounced compared to what I had become accustomed to by then.

I still can barely tolerate carrying on a conversation on a cell phone though. The latency and compression artifacts are just horrible compared to a landline. VOIP has gotten pretty good though. I can't tell the difference between a good VOIP landline and a POTS line.

I'm in the military. I have found that the habit of saying "over", learned as crowded circuit management for open radio circuits, is quite useful in teleconferences and VTCs, and for similar reason. It makes it clear that you're handing over the circuit. "Out" means you're leaving the circuit.

I think that can work well, as long as people also adopt the military/aviation habit of speaking crisply and not rambling on to hog the channel until they're absolutely sure they've emptied themselves of every possible thought they could ever have on the matter. Like I just did with every word after "rambling on". ;)

Yeah, this. The experience with overseas calls I was referring to was talking to my then-girlfriend who was spending a year studying in France. Saying "over" all the time is not very romantic.

Her: I miss you so much, your touch, your smell. I can't wait to hold you in my arms and gaze into your eyes.

You: Copy.

On the amateur radio side you see both types mixing in pretty amusing ways. On the one hand there's contesters and dx-ers that are all about confirming contacts as fast as they can, and on the other there's more casual people that'll talk about anything and everything that comes to mind. In my experience both sides use some amount of procdural language, but at very different cadences.

I gather some senior military people answer calls with a curt “Speak!” - and will get the hump if a junior presumes to “Out” them.

In the early 1990s I was sharing a flat in Edinburgh with a guy who's dad was working in Nigeria. The delay was routinely 4-5 seconds, which almost always took us a frustrating 30 seconds or so to sort out while we went backwards and forwards, both saying "no, you start" at the same time, leading to 10 seconds of silence, then both starting again...

4-5 seconds??? How is that even possible (with 1990s technology)? Even round-trip light time to the moon and back is less than three seconds.

If you use something like FaceTime over a cell phone, the audio quality is miles beyond anything any landline ever provided.

There was a hack to force a call over cable I used to use when I did a lot of international calls for BT when I worked on international interconnect for x.400

You should note that most landlines have significantly more delay than they used to have 50 years ago.

All landlines now get digitised and packetized, and usually go over an IP network, frequently via the landline companies HQ hundreds of miles away, before heading back to your neighbours house who you were calling...

Data is the same - If I ping my next door neighbor, from my broadband connection to his, it goes via London (my ISP's headquarters) and Manchester (his ISP's headquarters) before coming back to him, with a round trip latency of >20ms. In sound terms, that delay is like him standing in the next room over.

> Data is the same - If I ping my next door neighbor, from my broadband connection to his, it goes via London (my ISP's headquarters) and Manchester (his ISP's headquarters) before coming back to him, with a round trip latency of >20ms. In sound terms, that delay is like him standing in the next room over.

I feel like that would be enough to be basically perfect, though. If only we could cut down on everything else in the chain adding its own latency.

I think the rule of thumb I used to go by when recording myself playing guitar was that 20ms was a noticeable delay, 100ms was sort of tolerable and anything more than that was enough to make my picking lose synchronization.

I remember hearing 16 ms being the general threshold for most people recognizing out of synch audio.

16ms is also approximately 60 frames/samples second (hz).

There's no compelling reason we couldn't have IP audio links (with an easy calling interface) that have no such compression artifacts. I would actually call it more of a noise gate issue perhaps trying to save bandwidth by maximizing the compressibility of quiet parts as if they're total silence, signal off. That kills the intimacy IMO.

We've had it for so long now with digital cell phone calls, even HD calling, certainly Zoom et al (some are particularly aggressive on the noise gate when others are speaking over you).

The process of waiting to create the first packet to send (even with no compression) will always be slower than a system where you just send the audio instantly as an analog signal. Even the process of waiting for a single "sample" of audio (for a tiny tiny packet) is technically slower (but of course no one does that: they tend to group together at least 2ms of audio into a packet). The only way you can go faster than a classic land line (assuming there were no signal repeaters: like, this is one of those landlines where as you get further away the signal also gets quieter) is if you can go a shorter distance or use materials with less resistance--maybe "lower relative permittivity"? I don't know exactly what measurement you use here as I don't remember enough physics--to build the wiring or (probably your best bet) switches.

I believe the velocity factor actually depends mostly on the dielectric insulator used.

Not sure why you've been downvoted, it's at least partly true with my idealised understanding of transmission lines

It would depend on the characteristics of the transmission line used to transmit the signal.

Is noise gating why you can't talk over each other? I am terrible at doing this (I think of it as synthesis - 2 excited ppl grabbing the idea, running with it, then the other interrupts and takes over) and while I acknowledge it's a bad behaviour, why do video calls or most digital audio ones not let it happen? I get there's delay so they can't exactly blend the two audio streams together, but what is this crazy limitation that only one person can talk at a time?

Delay/latency is a totally separate issue that also has negative effects but not in a way that I would characterize as intimacy. Full duplex vs half duplex plays into it as I alluded: the symptom of half duplex is that the louder person "wins" temporary exclusivity which causes the quieter source to drop out in a way that isn't entirely different from what a noise gate does; the difference is that dropping out due to half duplex is based on the relative levels of the two sources and dropping out due to a noise gate is based on the absolute level of the source being above some determined noise threshold. Either way, all the dropouts where quiet becomes silent result in a lack of breath noise, saliva noise, the kind of laugh that manifests as just a bit of a strong nasal exhale, and plenty of other sounds. Think ASMR videos.

I never thought I'd miss working in a call center, but man do I miss my landline Jabra hardwired headset with an in-line mute button!! That place was a hellhole, but their call systems were fantastic.

I have a Logitech H390 which is better than any headset I ever used in call center(mainly Plantronics). It has inline mute. It's only $30 - $40. Also the call systems I was using were often crap, where every 30th call would just be static or weird behavior like agents getting routed to each other.

Reply on news.ycombinator.com