> Ethernet had to adapt to deterministic real-time needs

Without being able to get too into the telco detail, I think the lesson was that hard realtime is both much harder to achieve and not actually needed. People will happily chat over nondeterministic Zoom and Discord.

It's both psychological and slightly paradoxical. Once you let go of saying "the system MUST GUARANTEE this property", you get a much cheaper, better, more versatile and higher bandwidth system that ends up meeting the property anyway.

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burnished 6 hours ago | parent | next [-]

Yeah, big differences between an absolute guarantee and "we'll take as much as we can get"

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wat10000 5 hours ago | parent | prev [-]

I saw a story once, which may well be completely made up, about why AT&T got out of the cell phone business. They had a research project, but reliability was an issue. They couldn't see a way to do better than 1 dropped call in 10,000. Their standard for POTS at the time was 1 in 2 billion.

Seeing that the tech would never be good enough, they sold off the whole thing for cheap. Years later, they bought it back for way, way more money because they desperately needed to get into the cell phone business that was clearly headed to the moon.

I totally understand the pride they had in the reliability of their system, but it turns out that dropped calls just aren't that big of a deal when you can quickly redial and reconnect.

	▲	projektfu 4 hours ago \| parent [-]
		Seems a little sus. AT&T basically created the cellular mobile phone, and built up an analog, then digital system (D-AMPS/TDMA). AT&T sort of sold out the mobile business in 2004 to Cingular (BellSouth) because TDMA was a dead end. They then bought BellSouth back in 2006 and carried on with CDMA. Those old phones had a long range. It was hard to make small ones because the old AT&T towers were much farther apart, up to 40km. Meanwhile, their competitors focused on smaller coverage areas (e.g. 2km or less for PCS) and better tech (CDMA), and it seemed to pay off.