4 ms·
The national air raid sirens were controlled over random POTS lines[1]. The theory was that a dedicated system would need proper upkeep and testing, but when a
by wolfgang42 10y ago
The national air raid sirens were controlled over random POTS lines[1]. The theory was that a dedicated system would need proper upkeep and testing, but when a telephone line goes down the customer at the end of it will notice and file a complaint.
[1] https://en.wikipedia.org/wiki/HANDEL https://en.wikipedia.org/wiki/HANDEL