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Implementing E911 On-prem: Goals, Issues, Approaches
- Requirements – Summarizing the new E911 regulations
- Issues – Listing key problems and decisions
- Approaches – Suggesting next steps
- Dial 9-1-1 requires that people can reach the public safety answering point (PSAP) from any phone without needing to dial additional digits for trunk access.
- Notice must be served to a central location, whether on-site or off-site, where someone can easily see or hear that a 911 call was made and from where it was dialed. This applies if notice can be provided by the phone system without improved hardware or software.
- Dispatchable location, which includes the street address of the calling party and additional information to adequately locate the caller like room number or floor number, needs to be communicated to the PSAP. “Fixed” devices must do this automatically, and “non-fixed” services must be automatic if technically feasible.
- Dial 9-1-1 requires your dial plan and telco call routing to connect the caller to the PSAP, which is straightforward for telcos to do at single sites that have fixed-in-place stations. The first problem is if you have a multi-site system that spans locations covered by multiple PSAPs. The second is sending the right calling number to the PSAP, both for location (see below) and for callbacks, should the call be disconnected. If you have non-DID extensions or have VoIP phones that users can move, you need a system that supports emergency location identification number (ELIN) capabilities.
- Notice gives real-time alerts to designated on-site or off-site personnel, facilitating emergency personnel escort. The first issue is whether your present system can be configured to provide this notice now without new hardware or software. If so, 911 notification needs to be configured in the system, and if not, you need to decide whether notification is important in your organization. The second is who should get the notices and how. You need to decide if you have staff at the physical site(s) who can help emergency responders and, if so, decide on the best combination of notification options ranging from phones, desktop application pop-ups, emails, and text messages.
- Dispatchable location – The E911 system doesn’t directly transmit location information but rather associates the calling DID number (or ELIN) with a location database accessible by the PSAP called the private switch-automatic location information (PS-ALI). PS-ALI is traditionally hosted by telco carriers, but increasingly is hosted by service providers who you need to select and pay in addition to telco. The first problem is to find out what your options are for PS-ALI and to decide on your hosting approach. The second is handling “moving” VoIP stations that continue to work even if moved by a user to another location and deciding whether to “lockdown” the port or to install a system/service that detects the move and updates the PS-ALI location. The “granularity” of the location information is one of your most important decisions – VoIP station room-level location is more complex because it requires tracking the phone MAC addresses to network ports, compared to the floor-level location that can use the phone’s subnet IP range.
- Dial 9-1-1 determines the native capabilities of your present MLTS system to implement 9-1-1. You should work with your vendor to pinpoint “gaps” in those capabilities. Then identify and select the right combination of systems and services to meet these needs.
- Notice starts with existing staff who have already been helping “first responders” when emergency vehicles arrive. Do they meet responders at the door or go directly to the person in need? Determine responsibilities, negotiate the best notification method(s), set procedures, and train staff.
- Dispatchable location assesses your existing station/location database and extends as necessary for additional location granularity. PSAPs have specific format requirements for addresses, working against a nationwide database of street names. Work with your vendor(s) to validate all addresses and, if you have “granularity” of floor- or room-level, set a standard for the typical 20-character LOCATION field (e.g., BLDG2 FLR3 RM2301) used in the PS-ALI. If you are doing room-level location, and depending on the system/service you select, you will need to document all network switches and the rooms served by each port.
"SCTC Perspective" is written by members of the Society of Communications Technology Consultants, an international organization of independent information and communications technology professionals serving clients in all business sectors and government worldwide.