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GlossaryDispatch and call records

Enhanced 911

Enhanced 911 supplies callback and location information with a 911 call. Learn what E911 adds and why the displayed location still needs interpretation.

Enhanced 911, or E911, adds information and routing capabilities to basic 911 calling, notably supplying a callback number and caller-location information to the answering center. It helps staff identify where assistance may be needed. The information available depends on the phone service and system; E911 does not guarantee a perfectly precise incident location.

Number and location are different information

Automatic number identification, or ANI, provides a telephone identifier. Automatic location identification, or ALI, supplies associated location information. New York's 2025 statewide 911 plan describes these functions and explains how a landline number can be matched to an address in a database. New York State 911 plan

Mobile calling presents a different location problem because the device can move. A historic GAO review explains the distinction between an address tied to a fixed line and a location determined for a wireless caller. Its 2003 rollout figures are historical and do not describe present availability. GAO E911 explanation

For a resident reading a record, the important question is what the displayed location represents: a registered address, an estimate for the handset, a network location, or a location provided in conversation. These should not be treated as interchangeable.

Example

Hypothetical example: A mobile caller reports a fallen branch near a trail entrance. The answering center receives the phone number and an approximate location. The caller supplies the entrance name and explains that the branch is farther along the trail.

The automatically supplied position helps orient the call taker, but the response location is refined through the conversation. The phone's position and the obstruction's position are related without being identical. A map point from the call record cannot establish the exact spot of the hazard unless the field definition supports that interpretation.

Common confusion

E911 is different from Next Generation 911, or NG911, which uses an internet-protocol-based infrastructure to support richer routing and information exchange. E911 information can be relevant within a transition to newer systems; the names are not simply quality ratings for individual calls.

E911 is also unrelated to automatic vehicle location, which tracks response vehicles rather than the caller. A caller-location field does not reveal where an ambulance was when assigned.

Reading local capability claims

Check the type of service and the source of location data before interpreting accuracy. Avoid treating an E911 label as evidence that a specific apartment, floor, or person was automatically identified. A center's current technical documentation is needed for a narrower capability claim.

Sources