Do you have any idea whether a DECT phone system such as my Synergy 5500 loses any of its existing functionality if I retain it and use the BT DV Adapter rather than switch to new BT DV handsets? Intercom and call transfer functions between handsets would be unaffected, but I was thinking more about the answerphone capability...
I guess audio quality should improve; current landline's pretty scratchy...
The DV adapter just presents a normal phone connection, so plugging your existing DECT phone system into it, would not affect your phone`s function.
You would have to turn off 1571 if you wanted to use your existing answerphone.
This Ofcom document provides information about back-up power for FTTC street cabinets. Page 42 column 2 onwards: BT cabinets = 4 hours minimum. Read also on Page 44 about back-up power (or lack thereof) at mobile phone base stations.
https://www.ofcom.org.uk/__data/assets/pdf_file/0023/186413/Connected-Nations-2019-UK-final.pdf
More on power supply resilience in general at https://www.raeng.org.uk/publications/reports/living-without-electricity ( at Page 8 )
You will find that in general most comms systems are backed up by 4 hour UPS systems or in the event of critical systems like telephone exchanges generators are used.
With digital voice the consumer is lumbered with providing some of the power and the cabinet also gets powered.
A normal consumer UPS will last about an hour unless you pay a lot more.
The cabinet will be supported for 4 hours.
Your local mobile mast is also supported for 4 hours, but if it's like where I live it will drop after an hour.
So - any outage over 8 hours, like the north of england just lately, then everybody will have no service. This means no emergency services what ever.
Welcome to the new world!