Maggie Koerth-Baker of BoingBoing interviews Brough Turner, a phone system expert, about why it’s hard to make cell phone calls during an emergency. Turner addresses the mechanics and limitations of cell phone networks and points out that, nostalgia notwithstanding, the pre-cell phone era faced its own technical problems:
Well, say you’d have an earthquake in California. This was for the old Bell system. The national long distance routing has a set of standard, predefined routes and it had network control centers in New Jersey and other places. Things would get overloaded and they would manually intervene by putting access restrictions on new calls coming into the area that was congested. In the 60s, 70s, and 80s they would let through one out of every five call attempts. They were doing that manually and just arbitrarily to reduce congestion.
(HT: The Big Picture)