RE: London incidents

Some of the problems on the mobile networks were the
result of a protocol to reserve mobile capabilities for
the emergency services. The police have the authority to
switch cells to emergency service and then people with
specially registered SIM cards in their mobile can
take priority. Presumably, some amount of capacity is
also held in reserve for these people as well.

  Yes, a certain amount of capacity can be placed on reserve for the holders of priority access SIMs. You only get those issued to you by the government. This can include critical emergency services personnel, selected government officials, important members of the financial services community, etc....

  I don't know the specifics of how much capacity is reserved, but this sort of thing has been done on telecommunications networks for a long time. Back before cell phones existed, you could have "flash" traffic on the DDN or even the PSTN, and when placing a flash call the phone system would disconnect anyone that stood in your way of getting the connection you wanted.

  You had to be using special telephone equipment, or connected to a special operator with the right equipment, and you had damn well better be sure that your call was worthy of knocking anyone else off the network, but the capability was there. Even the President would normally make his calls at lower than "flash" priority.

  There were lower levels of priority that you could also use, but "flash" was the top one that I heard about.

I had moved the weekend before and my landline was not
yet installed. Also, I live near a large hospital. I noticed
that my mobile didn't function at all even late on Thursday
unless I left home and travelled a kilometer or two from
the hospital. Presumably, the cells in this suburban
location had also been switched to emergency service.

  Could be, but I'd be willing to bet it was more a matter of the cell just being overloaded. Traffic reservation for priority access SIMs is only going to take a small amount of the bandwidth available. The problem is that even normal heavy traffic can overload a cell, and what was seen during the time you're talking about was anything but "normal heavy".

Brad Knowles <> writes:

  There were lower levels of priority that you could also use,
but "flash" was the top one that I heard about.

The four buttons on the "1633" row of an AUTOVON telephone are labeled
P, I, F, and FO for Priority, Immediate, Flash, and Flash-Override.
The fifth (normal) level is of course routine, with no priority code

My understanding is that many (most?) phones could not issue the
higher priority levels. Don't want some E-2 in a guard shack to
misdial a number and knock off a four-star who's speaking with the
Joint Chiefs. :slight_smile:


See also and , as well as and which explain those Fo,
F, I and P keys on AutoVON 16-button WECo 2500s.

-- jra