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Cuyahoga County: PSAP Assessment
5. The MSC sends the call to the Local Exchange carrier who receives both
the voice signal and the 10-digit ESRD and ESRK routing numbers. The
call is now in the traditional E911 Tandem system used for wired calls,
and the call is processed by a Selective router or 911 Tandem.
The routing number is used to decide automatically which emergency call
center is appropriate and passes the call on specialized E911 trunks,
where the PSAP receives a 20-digit Automatic Number Identification (ANI)
consisting of the ESRD and the ESRK.
6. The emergency call center operator receives the 9-1-1 voice call and a
computer receives the unique 10-digit ESRK routing number. Using the
ESRK routing number, the computer then connects to the location
information database and retrieves the data that has been populated
including the caller’s wireless number, the tower’s address, and the
caller’s exact latitude/longitude coordinate location. At the same time, a
computer mapping application (if available) can then use the
latitude/longitude data and display this information on a map on the call
taker’s PC.
9.3 Infrastructure
Cuyahoga County can and should update its aged 9-1-1 infrastructure to include
a distributed network with SONET ring technology. This new architecture and
investment would assume four to five host sites for Regional Dispatching. There
are huge benefits to investing in such a platform, not limited to the importance
of load-balancing of the calls and the ability to failover call dispatching in the
event of a disaster.
The new 9-1-1 technology supports many groups sharing a single controller. On
Windows Server Systems, a 9-1-1 controller is a server that responds to security
authentication requests (logging in, checking permissions, etc.) within the
Windows Server domain. A domain is where a user may be granted access to a
number of computer resources with the use of a single username and password
combination.
9.4 Technology Roadmap
Cuyahoga County should create a prioritization plan to upgrade/update those
PSAPs that will not be consolidating quickly (e.g., within the next two years to
be 9-1-1 Phase Two Technological compliant). All 9-1-1 Controllers with the
exception of Fairview Park are considered “end of life” and should be replaced to
avoid any immediate issues in delayed response time related to dispatching.
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