[jcrawfordor]

Cordless phones are a whole different and rather interesting topic. The huge security issues with early cordless phones lead to DECT (or technically DECT 5.0) becoming widespread in the US, and it's actually a rather interesting protocol with a very complex and rich set of capabilities considering we normally only see it used for simple cordless phones. IP over DECT is an uncommon but interesting application.

[foepys]

There are some smart home devices that use DECT Ultra Low Energy to communicate with their base station. It's a pretty cool tech because DECT uses its own frequency band and doesn't interfere with bluetooth or wifi in the often highly congested 2.4 and 5 GHz bands. Even firmware updates are possible because the bandwidth is large enough to push some megabytes through.

[jcrawfordor]

That's very cool. When I was a kid, a nearby department store (Fred Meyers on 39th and Hawthorne) used a large-scale DECT system for employee-to-employee and paging. Each staff member carried what was essentially a ruggedized cordless phone with an earpiece and they heavily used DECT's "intercom" handset-to-handset feature to talk to each other, and it was all on a PBX with their outside phone lines. I believe it was a Panasonic system. Panasonic seems to still offer such a setup that uses IP for coordination between the multiple DECT "cells," but I'm not sure what was in use at the time. I remember it giving me an overwhelming feeling that my home's DECT cordless phone was a disappointment to the technology's capabilities.

For that matter I once had a job where I had a WiFi IP phone that I carried around, but I think cellphones have gotten cheap enough for corporate users that the wind is out of those sails. I keep thinking about buying one of those on eBay...

[majewsky]

This sounds very similar to the phone network that the Chaos Computer Club uses at their events, the biggest one being the Chaos Communication Congress. Everyone who wants can bring a DECT or GSM phone and register a 4-digit extension, and each congress, several thousand people do. The whole venue, as well, as some nearby hotels, are littered with DECT and GSM base stations. There's also bidirectional interconnectivity to the regular phone network. It's always one of my favorite parts of Congress, but it has kind of ruined me since I have trouble taking tech conferences without their own phone network seriously. :)

(Cave-at: I'm not involved with the technical implementation. I just know the system as a user.)

[tim--]

DECT VoIP base stations are still very much a thing.

http://www.grandstream.com/products/ip-voice-telephony/dect-...