NextGen 9-1-1 Inside the PSAP

If your career is INSIDE the Public Safety Answering Point (PSAP), one question might be “How will NG9-1-1 help us do our job?”

In speaking with Telecommunicators (those dedicated individuals that answer your 9-1-1 call), many identify the following to be important:

  • Reduce the number of transfers– in other words, have the network route wireless 9-1-1 calls to the correct PSAP the first time, eliminating the need for 9-1-1 Call Takers to transfer the call elsewhere. note: I’ve listened to a lot of 9-1-1 calls, it can literally freak people out to tell them that you cannot help them, that they are located in another jurisdiction and you will need to transfer the call. Recently, a mother whose child needed assistance called 9-1-1 and was told that her call needed to be transferred. She became extremely upset. Later, she went to a local TV station to complain. Dan Koenig, from my team, and I were interviewed for a segment to explain how the current system works. 

Today most wireless 9-1-1 calls are routed, not by the callers location, but by which cell tower and cell tower face (sector) their mobile phone is connected to..

In the example below, the 9-1-1 caller is connected to a cell tower and sector that is ‘programmed’ to send all 9-1-1 calls to Municipality A. This is simply a limitation of how the traditional 9-1-1 network functions today.

PSAP A will receive this 9-1-1 call.  Once they determine the 9-1-1 callers location, they will transfer the call to PSAP B.

Cell Sector

  • NextGen impact:

With Geospatial Routing, the location of the caller is determined first. This information is then passed on to the GIS mapping function, which should then route the caller to the correct PSAP. In the picture above, the NextGen system should route the 9-1-1 caller directly to PSAP B.

Update: Admiral David Simpson of the FCC (Bio Here) posted a comment on this blog, mentioning that there are numerous occasions, throughout the country, where the mapping capabilities of (in this scenario) PSAP A would not provide the location of the 9-1-1 caller, so the Call Taker would not know where to transfer the call to provide assistance.

It is important to note that the above example addresses only a single  aspect, routing the call to the correct PSAP. Next post, we will look at the Holy Grail of identifying the exact dispatchable address of the 9-1-1 caller…

2 thoughts on “NextGen 9-1-1 Inside the PSAP

  1. Joseph Elfelt

    My comment pertains to the “holy grail” of location when someone with a cell phone calls 911. Chuck, the comment you referred to by Admiral Simpson points out the problem. A PSAP will always get phase 1 coordinates for a 911 call. But those are the coordinates for the cell tower that is carrying the call. The person that needs help can easily be several miles away.

    The problem involves phase 2 coordinates which are supposed to provide a reasonably good location for the caller. Sometimes the wireless carrier (1) does not provide any phase 2 coordinates or (2) does provide phase 2 coordinates but they have such poor accuracy as to be largely worthless. One reason this problem exists is that the FCC allows wireless carriers huge exemptions from the requirement that the carrier provide any phase 2 coordinates for 911 calls. Also, sometimes the technology the carriers uses to produce phase 2 coordinates does not work very well.

    Often a 911 caller can provide a useful street address or otherwise give the dispatcher a sufficient description of their location. For those calls, phase 2 coordinates do not provide much added value to the issue of location.

    But how does the dispatcher know the caller’s location, and thus where to send help, when the wireless carrier does not provide good phase 2 coordinates and the caller cannot describe their location?

    When this problem arises then the dispatcher can ask the caller to browse to and then tap the “Next format” button until the yellow screen appears. That screen displays the caller’s location using same coordinate format that PSAPs use. Usually in well under a minute the coordinates are determined to an accuracy of 10 meters or better. The caller can then read the coordinates and accuracy value to the dispatcher.

    I am the developer of FindMeSAR ( This browser app is a public service and part of my way to ‘pay it forward’.

    Four coordinate formats.
    The “Next format” button will loop through four coordinate formats, including USNG, and each one has a different colored background.

    Works offline.
    The first time you open the app it is saved on your phone in a special part of the browser’s memory. The app includes an icon that you can save on your homescreen.

    For more information please tap the “About” button.

    Every PSAP from the biggest to the smallest can use FindMeSAR to help solve the problem of getting an accurate location for wireless callers. I am always happy to answer questions and my contact information is under the “About” button.


  2. Dave Simpson

    Thanks Chuck for highlighting a critical issue for communities today. Too many lives are lost because 911 calls go to towers that cross 911 jurisdiction borders, are consequently sent to the wrong PSAP which can’t resolve the callers address because their computer aided dispatch maps “end at the county line” … Let’s move forward as a nation to realize NG 911. PSAPs are “on point” as communities address a growing range of emergency issues and we should support attainment of NG911 capabilities with the same priority we place on National Security issues.

    Liked by 1 person

Comments are closed