When a single system isn't enough
Back in 1935, tech was emerging. Before that you had church bells and signal fires to warn of emergencies.
Look at the situation today.
Tech has moved so quickly and without a thought for such needs.
Or has it ?
Anyone remember when VOIP started to be offered to domestic customers.
There were several choices, but if one recalls correctly, only a couple that offered 999 access.
One was Vonage (still going today).
That is why we chose them.
We did away with our copper phone line and had cable internet. That worked.
Until. Yes. You know whats coming.
Power cut.
(Even cordless phones knew that issue, and a lot of base stations had battery back up compartments.)
So what to do ? Pop to a neighbour and use their landline phone !
What might be the future is satellites with 999 capabilities, but also phone boxes which are linked via copper network to a battery backup exchange. But much much smaller than now.
We all know that an EM pulse knocks out tech, batteries run out, rain interrupts satellite.
So, we find, and agree, on a multi network that is resilient and redundant.
Or we just put big hand bells in cabinets.