Date: Sat, 25 Jul 92 15:32:10 -0500
From: martin@datacomm.ucc.okstate.edu
Newsgroups: comp.dcom.telecom
Subject: 911 Nightmare
Organization: TELECOM Digest
X-Submissions-To: telecom@eecs.nwu.edu
X-Administrivia-To: telecom-request@eecs.nwu.edu
X-Telecom-Digest: Volume 12, Issue 584, Message 3 of 9

According to a report on Tulsa's KTUL television, gridlock in the
telephone system may have contributed to the death of a lady on
Saturday, July 18.  On that morning, tickets to a Garth Brooks concert
went on sale and there was much congestion as people tried to place
orders.  A Dr. Hardy, of Tulsa, observed his wife was having a heart
attack and, after starting CPR, tried to call 911 to summon an
ambulance.  What he heard was a busy signal.  Dr. Hardy said that he
repeated dialing 911 seven or eight times before finally getting
through.

     He said that he really didn't know how much difference the delay
caused in the outcome of the event, but valuable time was lost.

     A spokesman for Southwestern Bell explained the dilemma of the
economics of providing enough capacity to handle large loads as
opposed to normal activity.

     It seems to me that a sensible remedy to this and similar
problems around the country would be to program the system to start
dropping calls, if necessary to free up access to 911.  Would this
make people mad?  You bet it would, but it is still better than trying
to dial the standard emergency number, only to get a busy signal.  The
algorithm, here is simple.  John Q. Public just dialed 911.  Are all
circuits busy? Knock off the first one that isn't from or to an
emergency service.


Martin McCormick WB5AGZ   Stillwater, OK
O.S.U. Computer Center Data Communications Group


[Moderator's Note: The problem is *NOT* in deciding how to handle a
911 emergency call *once you have identified the call and know it is
to go to the police.*  The problem comes up in first identifying the
call. Let's say ten phones on my desk are ringing at one time. One is
my brother telling me the building is on fire and to flee for my life
with the cats, etc. Another phone call is from a friend inviting me
over for pizza and beer. When I get the 'house on fire' call, I know
what to do with no further delay. The question is how do I know which
ringing line to answer *first*? Should I hire ten people to stay there
and answer calls in the event ten come at one time just so I'll be
immediatly notified that the house is on fire?  

Phone systems are the same way. How many calls should be dealt with at
the same instant in order to prevent the possibility that an emergency
call will receive delayed handling?  What happens if I have the
ability to deal with that many then I get that many plus one more?
Typically the ability to deal with 10-12 percent of the subscribers at
any one time is more than adequate -- and that is during the busy
times of the day. Maybe five percent of the subscribers (big maybe)
want to use the service at the same time during off hours. How much
should telco spend (and you the subscriber pay) to have the essence of
a 'non-blocking' switch, if there is such a thing?  

The modern CO does not know the difference between one off-hook and
another *until it finds time to go and get the caller's request.* At
least one advantage of the old manual phone system was that a steadily
flashing lamp on the switchboard meant a routine call; a rapid off/on
flashing (because the subscriber was tapping the hook rapidly) would
usually catch the eye of an operator who would then go to that one
next *presuming it to be an emergecy*, and giving hell to the
subscriber for flashing like that if it was not. (A rapid blink-blink-
blink of a light on the board was universally accepted to mean 'oper-
ator, talk to me now this is urgent.').  PAT]