NG9-1-1 & GIS glossary

Defined in: FCC rules, 47 CFR Part 9

What it means: The part of the FCC's rules that covers 9-1-1 and 911 reliability, including dispatchable location, MLTS obligations, covered 911 service providers, and the NG911 transition rules.

In plain terms: Part 9 is the FCC's 9-1-1 rulebook: who has to do what, and by when.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010 · Also: FCC definition at 47 CFR § 9.28

What it means: The state, regional, Tribal, or local government body with responsibility for 9-1-1 in a given area. In the FCC's NG911 rules at 47 CFR § 9.28, the 911 Authority is the party that designates NG911 Delivery Points and makes valid requests of originating service providers.

In plain terms: If 9-1-1 in a region were a building project, the 911 Authority is the owner who signs the contracts and decides where the doors go.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: The three-digit number for mental health and suicide crisis support, separate from 9-1-1. The FCC adopted rules in 2024 requiring wireless calls to 988 to be georouted, meaning routed by the caller's approximate location instead of area code, so callers reach a nearby crisis center. Coordination between 988 centers and PSAPs is its own interoperability problem.

In plain terms: 9-1-1 sends help to you; 988 connects you with someone to talk to. Georouting makes sure that someone is nearby and knows local resources.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: A handset positioning method that uses GPS signals with help from the wireless network to find the caller faster. It's one source of the geodetic location on wireless 9-1-1 calls.

In plain terms: GPS with a head start from the cell network, so the phone finds itself faster.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: The legacy database record with the caller's address, looked up by the PSAP after the call arrives. In i3, location travels with the call instead.

In plain terms: The ALI is the address card pulled from a file after the phone rings.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: The caller's callback number, delivered with the call.

In plain terms: Caller ID for 9-1-1: the number to call back if the line drops.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: The security function at the edge of the ESInet that screens traffic entering and leaving it.

In plain terms: The BCF is the security checkpoint at the network's front gate.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: The PSAP's answering system: the positions and software telecommunicators use to answer, transfer, and log calls. It's often still called customer premises equipment (CPE). It has to be NG9-1-1 capable, or served through a Legacy PSAP Gateway, to receive i3 calls natively.

In plain terms: The PSAP's phone system and screens: the desk the call lands on.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-004 (CLDXF)

What it means: A location expressed as an address: street number, street name, community, and sub-address detail. Contrast with geodetic location.

In plain terms: What you'd write on an envelope.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-004

What it means: NENA-STA-004, the standard for how civic address elements are broken into fields, for example separating a street name's pre-type, name, and post-type. Getting addresses into CLDXF-consistent fields is often the largest single piece of GIS remediation.

In plain terms: CLDXF is filling in a form with separate boxes instead of one long line, so "N Main St" and "North Main Street" are recognized as the same street.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: The system telecommunicators use to create incidents, track units, and dispatch responders. CAD usually has its own map and address data, which should agree with the GIS data used for 9-1-1 routing.

In plain terms: CAD is the dispatcher's whiteboard, map, and unit roster in one. If CAD's map and the 9-1-1 map disagree, someone ends up double-checking addresses by hand.

Defined in: FCC rule, 47 CFR § 9.19

What it means: An FCC category at 47 CFR § 9.19 for entities that provide 9-1-1 capabilities such as call routing or ALI directly to a PSAP, or that operate certain gateways or a LIS serving two or more OSPs. It carries reliability certification obligations. Status turns on the function performed, not what the product is called.

In plain terms: The label follows the job, not the job title: if you do the routing or location work for a PSAP, the reliability rules follow you.

Defined in: Ground Truth Advisors working definition

What it means: The ongoing responsibility for keeping GIS data current, correct, and submitted on schedule, including who owns each layer and how changes flow to the NGCS provider.

In plain terms: Stewardship is owning the upkeep, like a homeowner: someone has to be responsible for the roof after the builder leaves.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: The i3 mechanism for one party to flag a data problem to the party responsible for it, for example a PSAP reporting a routing error back to the GIS data provider.

In plain terms: A discrepancy report is a formal "this looks wrong" ticket sent to whoever owns the data, with a way to track the fix.

Defined in: FCC rule, 47 CFR § 9.3

What it means: The FCC's term, defined at 47 CFR § 9.3, for a validated street address plus the additional detail, such as suite, apartment, or floor, needed to find the caller. It's the standard multi-line telephone systems and many providers are measured against.

In plain terms: "123 Main Street" gets responders to the building. "123 Main Street, 3rd floor, Room 312" gets them to the person.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010; NENA-STA-005

What it means: The i3 function that takes a caller's location and returns where the call should go, using the LoST protocol and GIS boundary data. If the PSAP or emergency service boundaries loaded into the ECRF are wrong, calls route wrong.

In plain terms: The ECRF is a sorting machine that reads the address on each envelope and drops it in the right PSAP's bin. A wrong boundary line means the right letter goes in the wrong bin.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-021; NENA-STA-024

What it means: NENA's standard format for sharing incident information between authorized systems, such as one PSAP's CAD and another's. The JSON format is defined in NENA-STA-021, and NENA-STA-024 covers how EIDOs are conveyed.

In plain terms: An EIDO is a standard incident folder, so when one center hands a call to another, the notes come with it instead of being retyped.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: NENA's professional certification for people working in 9-1-1.

In plain terms: ENP is to 9-1-1 what a PMP is to project management: a credential that says you know the field end to end.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-006

What it means: GIS polygon layers showing which law enforcement, fire, and EMS agencies respond in each area. They replace the Emergency Service Number (ESN) zones used in legacy 9-1-1.

In plain terms: Emergency service boundaries are the fence lines for who responds, drawn separately for police, fire, and EMS.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: The legacy code that identifies the combination of law, fire, and EMS agencies serving an address. The selective router uses it to route calls. In NG9-1-1, emergency service boundary polygons do the same job.

In plain terms: An ESN is a zip code for emergency response: one code stands for which police, fire, and EMS agencies serve that area.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: The managed IP network that carries 9-1-1 traffic between the edge of the system and the PSAPs. An ESInet is transport; it doesn't route calls to the right PSAP on its own. That job belongs to the core services running on it.

In plain terms: The ESInet is the highway. It carries the traffic, but it doesn't decide which exit each car takes.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: The i3 function that receives a call, asks the ECRF where it should go, applies policy, and forwards it to the next hop or the PSAP.

In plain terms: The ESRP is the air traffic controller: it asks where the plane should land, checks the rules for today, and clears it to the right runway.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: The legacy system that delivers a caller's callback number and address to the PSAP using ANI, ALI, and a selective router.

In plain terms: E9-1-1 is caller ID plus a looked-up address. It worked well for landlines at fixed addresses.

Defined in: NENA i3 Standard (NENA-STA-010) describes the interfaces; the term here is general usage

What it means: Connecting neighboring ESInets, for example across a state or regional line, so calls and incident data can be transferred between PSAPs on different networks. It needs agreements on routing, security, and data as much as it needs circuits.

In plain terms: Interconnection is building the bridge between two highways, plus agreeing on the speed limit and who pays for upkeep.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-006

What it means: Turning an address into a point on the map, either by matching it to an address point or by estimating its position along a road centerline's address range. Where address points are missing, geocoded locations are estimates.

In plain terms: Geocoding is estimating a house's spot by counting along the block. An address point is walking up and finding the door.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: A location expressed as coordinates, such as latitude and longitude, usually with an uncertainty value. Wireless calls often arrive with geodetic location first.

In plain terms: What you'd read off a GPS: a dot on the map with a circle around it showing how sure the phone is.

Defined in: General usage; see NENA-STA-006 for the data model aggregated data is validated against

What it means: Combining GIS data maintained by counties, cities, and Tribal governments into one regional or statewide dataset, validating it against the NENA GIS Data Model, and provisioning it to the NGCS. The hard part is agreement between the organizations that own the data, not the software.

In plain terms: Aggregation is sewing a quilt from squares made by different people. The seams have to line up, and everyone has to agree on the pattern first.

Defined in: General usage in state NG9-1-1 GIS programs

What it means: Comparing legacy MSAG and ALI records to GIS data to find addresses that disagree. The share of records that match is often reported as a match rate, and many states set a target before a PSAP moves to GIS-based routing.

In plain terms: The match rate is a report card comparing the old phone book to the new map. Every mismatch is a call that might route differently after cutover.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: NENA's architecture for end-state NG9-1-1, defined in NENA-STA-010, Detailed Functional and Interface Standards for the NENA i3 Solution. When a vendor or an RFP says "i3-compliant," it's worth asking which functional elements and which version of the standard they mean.

In plain terms: i3 is the building code for NG9-1-1. It doesn't build the house; it tells every builder how the pieces must fit so they work together.

Defined in: FCC rule, 47 CFR § 9.16

What it means: The federal law requiring MLTS users to be able to dial 9-1-1 directly, without a prefix, and requiring notification to a central location on site when 9-1-1 is dialed. The FCC implements it at 47 CFR § 9.16.

In plain terms: No "dial 9 first." Anyone in the building can reach 9-1-1 directly, and the front desk knows it happened.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: The i3 element that converts calls from legacy telephone networks into SIP so they can be handled by NGCS. It's how older originating networks reach an NG9-1-1 system during transition.

In plain terms: A travel adapter that lets an old plug work in a new outlet.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: The i3 element that lets a PSAP still running legacy call-handling equipment receive calls from an NG9-1-1 system.

In plain terms: The same travel adapter, pointed the other way: it lets an older PSAP take calls from a new system.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: The element that holds or determines a caller's location and supplies it to the call. Under 47 CFR § 9.29(b), an originating service provider that receives a Phase 2 valid request must use a LIS or its functional equivalent to verify customer location records.

In plain terms: The LIS is the carrier's address book for its callers, answering "where is this phone right now?"

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010; NENA-STA-005

What it means: The i3 function that checks a civic address against GIS data before a call is ever made, so providers can confirm an address is routable. It uses the same GIS data as the ECRF, which is why address points and road centerlines matter well before go-live.

In plain terms: The LVF is spell-check for addresses, run before the call ever happens, so the ECRF isn't guessing during an emergency.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010 · Also: IETF RFC 5222

What it means: The IETF protocol, RFC 5222, that the ECRF and LVF use to answer the question: for this location, which service boundary applies?

In plain terms: LoST is the question and answer format: "Here's a location; who serves it?"

Defined in: NENA i3 Standard (NENA-STA-010)

What it means: The i3 function that records calls, messages, and the events around them across the NG9-1-1 system, supporting records requests, quality review, and investigations.

In plain terms: The logging service is the flight recorder for every call.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: The legacy table of valid street names and address ranges by community, each tied to an Emergency Service Number. Comparing the MSAG and ALI records to GIS is one of the first steps in finding data problems before a transition.

In plain terms: The MSAG is the legacy system's phone book of valid streets and house-number ranges.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · FCC rule, 47 CFR § 9.3

What it means: A phone system serving many stations, such as a PBX, Centrex, or hosted VoIP system, as defined at 47 CFR § 9.3. MLTS rules apply to government agencies, schools, hospitals, and businesses that run their own systems.

In plain terms: Any phone system where you dial a code to get an outside line, or where one main number fronts many desks.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: The National Emergency Number Association, the standards body behind i3, the NG9-1-1 GIS Data Model, and CLDXF.

In plain terms: NENA writes the playbook most of the NG9-1-1 industry builds to.

Defined in: NENA-STA-006, NENA Standard for NG9-1-1 GIS Data Model

What it means: NENA-STA-006, the standard that defines the GIS layers and attributes NG9-1-1 needs, including road centerlines, site/structure address points, and the PSAP, emergency service, and provisioning boundaries. Most state and regional aggregation programs validate local data against it.

In plain terms: The GIS Data Model is the shared recipe card: every county can cook in its own kitchen, but the dish has to come out the same so the state can serve it.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: The move from analog, telephone-era 9-1-1 to an IP-based system that routes calls using location data from GIS instead of tabular address lists. Calls, texts, and eventually data travel over an Emergency Services IP Network and are routed by Next Generation Core Services. For most agencies the network is the part that gets bought; the GIS data is the part that decides whether it works.

In plain terms: Legacy 9-1-1 is like a switchboard with a printed phone book of addresses. NG9-1-1 is like a GPS navigation app: the call is routed by where the caller actually is, using a live map.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: The set of i3 functions that receive, route, and log 9-1-1 calls on the ESInet, including the ESRP, ECRF, LVF, BCF, and policy and logging functions. NGCS is usually procured as a service, and it depends on GIS data the vendor doesn't create.

In plain terms: If the ESInet is the highway, NGCS is the traffic control center: the signals, signs, and dispatchers deciding where each call goes.

Defined in: FCC rule, 47 CFR § 9.28

What it means: The location a 911 Authority designates where originating service providers must deliver 9-1-1 traffic under the FCC's NG911 rules at 47 CFR § 9.28 and § 9.29.

In plain terms: The delivery point is the loading dock. Carriers must bring 9-1-1 traffic to the dock the 911 Authority picks.

Defined in: FCC rule, 47 CFR § 9.29

What it means: The two stages of the FCC's NG911 rules at 47 CFR § 9.29. Phase 1 requires originating service providers to deliver 9-1-1 traffic in SIP to the NG911 Delivery Points a 911 Authority designates. Phase 2 adds delivery that meets NG9-1-1 commonly accepted standards, with location carried in a PIDF-LO or its functional equivalent. Each phase starts with a valid request from the 911 Authority.

In plain terms: Phase 1 changes the language calls arrive in. Phase 2 makes sure the location arrives inside the call, in a standard envelope.

Defined in: Ground Truth Advisors working definition

What it means: A record or feature that fails a validation rule. A non-conformance report tells a county what to fix; the useful ones say it in terms a GIS technician can act on.

In plain terms: A non-conformance is a failed inspection item, with a note saying what to fix.

Defined in: FCC rule, 47 CFR § 9.28

What it means: Under 47 CFR § 9.28, the provider that originates 9-1-1 traffic: wireline, wireless (CMRS), covered text, interconnected VoIP, and internet-based TRS providers. The definition is keyed to origination; supplying location or routing a call is a different function.

In plain terms: The OSP is where the call starts: the phone company, wireless carrier, or VoIP service the caller is using.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010; NENA-INF-011

What it means: The part of the ESRP that decides the next hop for a call using policy routing rules, such as sending calls to a backup PSAP when the primary is overloaded or closed. NENA-INF-011 is the operations guide for writing them. Who writes and approves these rules is an operational decision, not a vendor setting.

In plain terms: Policy routing rules are the call center's standing orders: "if we're full, send overflow to our neighbor." The PRF follows them.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010 · Also: IETF RFC 4119

What it means: The IETF format, RFC 4119, for carrying civic or geodetic location with a call. In i3, location travels with the call as a PIDF-LO rather than being looked up afterward in an ALI database.

In plain terms: The PIDF-LO is the address label stuck on the call itself, instead of a note someone has to look up afterward.

Defined in: NENA-STA-006 (Provisioning Boundary layer)

What it means: The GIS polygon that defines which authority is responsible for maintaining and submitting GIS data for an area. It settles who fixes an error when one is found.

In plain terms: The provisioning boundary is the property line for data: inside it, you're the one who fixes the map.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-006

What it means: The GIS polygon layer showing which PSAP answers calls in each area. The ECRF uses it to route calls, so gaps and overlaps with neighboring jurisdictions have to be resolved before go-live.

In plain terms: The PSAP boundary is the fence line that says whose phone rings. Gaps and overlaps are where calls get lost or argued over.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: The facility where 9-1-1 calls are answered. Some PSAPs dispatch directly; others transfer the caller to the agency that does.

In plain terms: The PSAP is the front door. Every 9-1-1 call knocks there first, whether or not the same building sends the ambulance.

Defined in: FCC rule, 47 CFR § 9.16

What it means: The federal provision that led the FCC to require dispatchable location for 9-1-1 calls from MLTS and other services. The MLTS compliance dates were January 6, 2021 for on-premises fixed phones and January 6, 2022 for non-fixed and off-premises devices.

In plain terms: Kari's Law makes sure the call gets out; RAY BAUM'S Act makes sure the room number goes with it.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010 · Also: FCC rules, 47 CFR Part 67

What it means: Text that is sent character by character as it is typed, so the telecommunicator sees the message forming. The FCC adopted RTT, at 47 CFR Part 67, to replace TTY on wireless networks, with backward compatibility to TTY and support for calls to 9-1-1.

In plain terms: Like watching someone type in a shared document: the telecommunicator sees each letter as it's typed, not a finished message.

Defined in: Ground Truth Advisors working definition

What it means: The work of fixing non-conforming GIS data so it can be used for routing and validation. It is usually a cycle, not a one-time project, because addresses keep changing.

In plain terms: Remediation is the repair work after the inspection. Addresses change every week, so the inspections keep coming.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-006

What it means: The GIS line layer representing streets, with address ranges on each side. Centerlines support geocoding, validation, and map display, and their ranges must agree with the address points around them.

In plain terms: Centerlines are the street map with house-number ranges written along each side of the road.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: The legacy switch that routes E9-1-1 calls to a PSAP based on the caller's ESN. NG9-1-1 replaces it with the ESRP and ECRF.

In plain terms: The selective router is the old switchboard operator, routing by a code instead of by the map.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010 · Also: IETF RFC 3261

What it means: The IETF signaling protocol, RFC 3261, used to set up calls in IP networks, including NG9-1-1. The FCC's Phase 1 NG911 obligation at 47 CFR § 9.29 is framed in terms of delivering 911 traffic in SIP format.

In plain terms: SIP is the dial tone and ring of the internet: it sets up the call, then gets out of the way.

Defined in: NENA-STA-006 (Site/Structure Address Point layer)

What it means: The GIS point layer with one point for each addressable location, such as a building, unit, or site. Address points are the most precise way to validate and route a civic address, and many agencies are still completing them.

In plain terms: Address points are a pin on every front door, rather than an estimate of where the door should be along the street.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: The i3 mechanism by which authoritative GIS data is provisioned into the ECRF and LVF. How often data moves through it, and who approves each update, are procurement questions worth answering in writing.

In plain terms: The Spatial Interface is the conveyor belt that carries your approved map into the routing system.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: The person who answers 9-1-1 calls and, in many centers, dispatches responders. NG9-1-1 changes what arrives at their screen, including location, text, and eventually media, more than it changes the job itself.

In plain terms: The telecommunicator is the first first responder: the person on the line before anyone arrives.

Defined in: FCC rule, 47 CFR § 9.10(q)

What it means: Sending a text message to 9-1-1. FCC requirements for wireless and covered text providers are at 47 CFR § 9.10(q), and providers deliver texts once a PSAP says it is ready to receive them.

In plain terms: "Call if you can, text if you can't." Texting helps when speaking would put someone in danger or they can't use voice.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · Key standard: NENA-STA-010

What it means: The older device people who are deaf, hard of hearing, or speech disabled use to type over a phone line. PSAPs must still be able to take TTY calls, and real-time text is replacing it on wireless networks.

In plain terms: A TTY is a typewriter that talks over a phone line; RTT is its modern replacement.

Defined in: Ground Truth Advisors working definition; rules come from NENA-STA-006 and state programs

What it means: Checking GIS data against the NENA GIS Data Model and against itself: whether required fields are filled, whether address ranges agree with address points, whether boundaries close without gaps or overlaps.

In plain terms: Validation is the inspection before the certificate of occupancy.

Defined in: NENA Knowledge Base Glossary, read NENA's definition

What it means: Legacy wireless E9-1-1 location levels. Phase I delivers the callback number and the cell site or sector handling the call. Phase II adds the caller's estimated latitude and longitude.

In plain terms: Phase I tells you which cell tower picked up. Phase II tells you roughly where the phone is.

Defined in: NENA Knowledge Base Glossary, read NENA's definition · FCC rule, 47 CFR § 9.10(i)(2)(ii)

What it means: A caller's vertical position, such as height or floor. Under 47 CFR § 9.10(i)(2)(ii), nationwide wireless carriers must provide vertical location within 3 meters above or below the handset for 80 percent of wireless 9-1-1 calls from z-axis capable devices, on the deployment schedule in that rule. Floor-level detail is also part of what makes a multistory location dispatchable.

In plain terms: Latitude and longitude get you to the building. The z-axis tells you whether to take the stairs.