I’ve designed several E911 systems. The old “three leg” ATT E911 system was designed around the Tandem compute infrastructure from 1990 or so. Unfortunately, some small municipalities can’t/won’t update.

Modern E911 systems replicate continuously, with a map of all resources, states, GIS info, audio and video feeds and a quality judgment of each. In most cases, remote devices will automatically connect to the most reliable-recent data (ms apart!) If a dispatch facility goes offline, there are others who have “up to the moment” data that is automatically arbitrated as authoritative.

Practice drills or a complete failure would be uneventful as C&C is automatically transferred. 

I don’t know exactly how this is done in Nashville, but a complete Central Office or NOC failure would have to go several layers deep to affect National Command Infrastructure, including PD dispatch. 

You can rest assured that the FIrstNet system survived this incident, as it will the next.

Mickey

On Mon, Dec 28, 2020 at 10:28 AM w3tom--- via arrl-odv <arrl-odv@reflector.arrl.org> wrote:

Anthony Quinn Warner, the Nashville bomber, had a specialty in alarm/security systems.

 

From a Public Safety perspective, it is interesting to note that in addition to taking down the Central Office (CO), that in turn took down the Nashville 911 System where the RV was parked, the lost of the Central Office also took out several other 911 Systems in near by jurisdictions. Redundancy in all phases of Public Safety Communications is a paramount design concept, including Radio/Data and 911 systems. With the failure of multiple 911 Systems from one act, I would think that the after-action report for this event would make for some interesting reading. What has not been made public is the potential loss of radio communications that may have occurred due to the Public Safety trunked radio system back-hauls on fiber routes through the Central Office near the event.

 

73, Tom – W3TOM  

 

From: arrl-odv <arrl-odv-bounces@reflector.arrl.org> On Behalf Of hopengarten@post.harvard.edu
Sent: Monday, December 28, 2020 9:33 AM
To: arrl-odv <arrl-odv@reflector.arrl.org>
Subject: [arrl-odv:31536] Anthony Quinn Warner NOT a Ham

 

Anthony Quinn Warner, the Nashville bomber, described by the Washington Post as “into phones and electronics,” does NOT appear in a search by name in the QRZ.com database.

 

Whew,

 

-Fred K1VR

 

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