* Posts by flec

11 publicly visible posts • joined 10 Jun 2019

Switch to hit the fan as BT begins prep ahead of analog phone sunset


"All that's happening here is the removal of the last remaining analogue component in the last mile"

No - System X is going too.

At the moment System X is dealing with that last mile of analogue-digital conversion.

Once it's digital end-to-end, there's no need for System X. The telephone "exchange" - which needs to be fairly close* to an analogue telephone handset - can now be anywhere.

https://telephonesuk.org.uk/exchanges/exchange-inside/ has some pretty pictures, and most of it is of the kit that won't be needed any more.

* circa 5 miles IIRC

What happens when What3Words gets lost in translation?


"Surely smartphones can embed the GPS data in the call metadata"

They do. It's called AML and is widely used in the UK.



'I can understand problems occuring when a phone's location services are a bit unsure and are just reporting position guestimated from what cell towers it can see. You can see that on Google Maps sometimes, when it paints an enormous circle to say "you're somewhere in here, maybe".'

It's exactly ^this^ which is the problem.

w3w is marketed as being a solution to being found an emergency, pinpointing the location to 3m.

So, perhaps folk download the app and try it at home. Mere seconds pass by, and they get a satellite view of their back garden. Wow, they say. Most impressive!

They don't appreciate they're in range of multiple cell sites, multiple nearby WiFi networks, and have a good strong data signal to help with A-GPS and hotspot/cell tower databases. All these helpers mean their phone can get a location, *fast*.

Then weeks later, out in the sticks, perhaps under some tree cover, in the range of only one cell tower, with no nearby WiFi, no/poor data signal, and in a panic not really knowing exactly where they are.... they open the app and rhyme off the first three words they see to the 999 call handler. They don't notice the massive blue circle. They don't appreciate they're relying on GPS acquisition alone which could take many seconds, perhaps even a minute or two, to get an accurate location. But it's too late. They've passed on those three words and they're in the system now.

Things have got slightly better. w3w produced a script for call handlers to follow; but fundamentally their system is still subject to spelling and transcription errors.

Speaking from experience.


The slight problem with lat/long, from the perspective of the untrained person who is possibly using them for the first time in what's likely to be a bit of a panic, is the multiple different formats and reference frames that lat/long can be conveyed in.

For the sake of argument let's assume the lat/long you want to convey is referenced to the WGS84 geoid.

Do you see it as:

Decimal degrees,

Degrees and decimal minutes,

or Degress, minutes and seconds

and then - whether or not negative numbers are used to convey locations south of the equator and west of the Greenwich meridian.

Is it interpreted by the receiver as another format?

If lat/long positions is read out by the user without understanding, it can be interpreted as another very easily.

The error in translation may be relatively insignificant (~500-1000m depending on circumstances), or may be highly error prone, or could result in an invalid coordinate).

This is why, I presume, UK Fire/Police/Ambulance have used OS eastings and northings (easily translatable to OS grid references) for years. Other than the numbers, there's nothing to misinterpret.

Speaking from experience after 22 years in mountain rescue.


Re: its a gimmick

"in UK OS NGR: SK123854 is a 10metre square"

Sorry to be fickle, but SK123854 refers to the south west vertex of a 100 metre square.

SK12348543 would be 10m (2+8)

SK1234585431 would be 1m (2+10)

BT providing free meals to coax its healthy customer support staff back into office as calls rocket amid pandemic


Don't worry about those dropped packets on a 999 call - it'll be all be fine. Just work from home on your broadband connection that you're sharing with the rest of the family during the day... what's the worst that could happen?


Microsoft hikes cost of licensing its software on rival public clouds, introduces Azure 'Dedicated' Hosts


Q: "Congratulations on the birth. Is it a boy or a girl?"

A: "....Yes."

Neuroscientist used brainhack. It's super effective! Oh, and disturbingly easy


Re: Let them dopamine themselves to death

You appear to have forgotten the story of the Golgafrinchans, and Ark Ship B.

When it comes to DNS over HTTPS, it's privacy in excess, frets UK child exploitation watchdog


Re: Help!

Ah, yes fair point - I misinterpreted eldakka's comment, thinking that that the "out of country provider" was using "standard" port 53 DNS.


Re: Help!

"Only if you are stupid enough to point to a DNS server located in the country you are in. Otherwise, they'll have no jurisdiction to force any laws on the DNS provider."

In the absence of a VPN, in this instance you're rather assuming that your local ISP isn't inspecting and rewriting the DNS responses from the out-of-country provider.


Re: Does this change anything?

You're thinking of TLS server name indication, where the client sends the hostname to the server in plaintext, a feature which allowed multiple HTTPS certificates to be served via a single IP address, thus effectively implementing Host-header support in HTTPS.

This is resolved by a TLSv1.3 extension - SNI encryption.