Next Generation 911 GIS Services

Screenshot of the North Carolina Next Generation 911 GIS Status by PSAP and County Dashboard map.

 

Currently in 911 systems, Geographic Information Systems (GIS) data are used for mapping a caller’s location and supporting dispatch functions. 911 calls are mapped based on address range, street name and city information stored in the tabular Master Street Address Guide (MSAG). The Automated Location Information (ALI) and MSAG validate addresses and route a 911 call to the correct Public Safety Answering Point (PSAP). 

Next Generation 911 (NG911) will allow 911 calls to be mapped by coordinates or address locations and GIS data will be used to validate address data and route 911 calls to the correct PSAP. GIS data will be used by the Location Validation Function (LVF) to validate address locations and by the Emergency Call Routing Function (ECRF) to geospatially route calls to the correct PSAP. This means GIS data will become mission critical and will be used for life safety. The GIS data for address information and service area boundaries will need to be accurate, kept up-to-date, and seamless across the state. The importance of data quality (accuracy, validity, consistency, timeliness, completeness) and sustainable data maintenance workflows are paramount. In the NG911 call flow architecture, when a location is identified by a new landline or digital service, it is validated against the NG911 GIS data before the 911 call can be placed. If a 911 call cannot be validated by the GIS, there may be a delay in the call being routed to a PSAP.

The NC 911 Board has contracted with GeoComm to assist with the NC NG911 GIS Project. Local agencies will continue to maintain their own GIS data and will submit their data to the State through GeoComm's GIS Data Hub. Submitted data will automatically load into the State’s standardized NG911 GIS database schema. GeoComm will provide managed services to help aggregate data from local agencies and assist in identifying and reporting any gaps, errors and discrepancies in GIS data. 

Local agencies that maintain authoritative data required for NG911 will also be responsible for the remediation of any errors and discrepancies identified by a series of data validation checks provided through the GIS Data Hub. It will be up to the local GIS authorities to clean up and maintain required data, as well as coordinate with neighboring jurisdictions to ensure there are no gaps, overlaps or redundancies in any of the required datasets. It is imperative that you understand the importance of GIS data in a NG911 system and start identifying what it would take for your agency to meet requirements. 

Important Things to Know

What are the required datasets I need to upload into GeoComm’s GIS Data Hub?

What are the required datasets I need to upload into GeoComm’s GIS Data Hub?

  • Road Centerlines
  • Address Points
  • PSAP Boundary
  • Emergency Service Boundaries
  • Provisioning Boundary
  • ALI Database Table
What is the Provisioning Boundary?

What is the Provisioning Boundary?

This is your area of responsibility for the GIS data you’ll be uploading into the GIS Data Hub.  This is one polygon that should be identical to the coverage area of all your PSAP boundaries.  For all the data you are responsible for maintaining, you need to have a polygon boundary around this. The emergency service boundaries will also need to cover this same area.

What if I do not have the ALI table?

What if I do not have the ALI table?

If you know who your service provider is, request a copy from them.  If you do not know your service provider, please reach out to your regional coordinator to find out this information.  If your provider is AT&T, Intrado or West the NextGen 911 GIS Team can request the ALI for you. If your provider is CenturyLink, your regional coordinator can assist you with filling out a request form to email the request. While you are awaiting receipt of the ALI, you can upload the MSAG which will still help identify areas needing to be corrected while you wait.

What are the required attributes for the NextGen 911 GIS Data Model?

What are the required attributes for the NextGen 911 GIS Data Model?

​​​​​​We have provided a table which lists the required attributes for each required and recommended layer. This table follows the NENA GIS Data Model standard. Please visit this NENA document for more information on the Civic Location Data Exchange Format (CLDXF) fields for the street name attributes.

The XML of the NENA schema and the field mapping spreadsheet are both part of the NG9-1-1 GIS GeoComm Tool package that may be downloaded from the State NG9-1-1 GIS services page.

How often can I upload and process my data?

How often can I upload and process my data?

​​​​​​As often as you would like! After you upload and process your data, you should receive your results within 1-2 hours. After you receive those results, you can upload again at any time. Feel free to upload and process your data after you have made updates to see how those changes have affected your results and score.

Is there an option for automating uploads into GIS Data Hub? (Related to this, Is there a way to point to a REST service?)

Is there an option for automating uploads into GIS Data Hub? (Related to this, Is there a way to point to a REST service?)

​​​​​​No, not currently.

How do I handle our Fire, EMS, and Law Boundaries when there are mutual aid agreements in place with adjacent jurisdictions? How does this affect the PSAP and Provisioning Boundaries?

How do I handle our Fire, EMS, and Law Boundaries when there are mutual aid agreements in place with adjacent jurisdictions? How does this affect the PSAP and Provisioning Boundaries?

If your mutual aid boundaries fall into your neighboring jurisdiction’s PSAP coverage area (calls are routed to your neighboring PSAP), you should split the emergency service boundaries at the PSAP boundary and add an exception code of “999” to the polygons that fall outside of your PSAP boundary. There is no need to remove them prior to uploading into GIS Data Hub. the “999” code will take care of this. Your neighboring jurisdiction should submit these polygons with the rest of their data to ensure 100% emergency service boundary coverage of their PSAP and Provisioning Boundary.

How does this affect my CAD system?

How does this affect my CAD system?

The legacy street name fields, the MSAG community and ESN fields are intended for legacy system purposes. Any additional CAD system GIS data required fields can be maintained in addition to the NG9-1-1 schema fields.

What happens with roads that border a county boundary or weave in and out of a county boundary?

What happens with roads that border a county boundary or weave in and out of a county boundary?

Roads that run along a boundary should run coincident (snapped to each vertex). The ranges for the neighboring jurisdiction’s side should be attributed 0-0. The neighboring jurisdiction should do the same, so no overlapping ranges are introduced into the statewide dataset.

If a road weaves in and out of county, it should be broken every time it crosses a boundary. Alternately, if it is more efficient to have a specific responder responsible for the whole road, then the boundary of the PSAP responsible for dispatching that responder could cover the entire road. Keep in mind that the Provisioning boundary and the emergency service boundaries need to cover this PSAP boundary 100% and this plan needs to be coordinated with the neighboring jurisdiction.

The ‘999’ exception code may also be used to exclude features in your dataset that weave in and out of your county and are maintained and submitted by the neighboring jurisdiction. Features with the ‘999” exception code are essentially removed as part of the GIS Data Hub ingest process, before quality checks are run. These features will also not be aggregated into the statewide dataset.

I know my ALI database addresses match my road centerlines and address points. Why is my synchronization rate so low?

I know my ALI database addresses match my road centerlines and address points. Why is my synchronization rate so low?

 A very low synchronization rate can be caused by incorrect or missing field mapping. We suggest double-checking your field mapping of ALI, roads and address points. The fields used in the synchronization check are:

    1.  
  • House number in address points and ALI database
  • House number suffix in address points and ALI database
  • Legacy street name components (parsed) in address points, road centerlines and ALI database
  • Ranges in road centerlines
  • MSAG community in address points, road centerlines and ALI database
How often do counties/PSAPs need to request their ALI moving forward?

How often do counties/PSAPs need to request their ALI moving forward?

Once a month is the suggested minimum to ensure new records are validated, but it can be requested and uploaded with your GIS data as often as you wish.