Acronyms & Key Terms Flashcards
NENA Knowledge Base Glossary
9-1-1
A three-digit telephone number to facilitate the reporting of an emergency requiring response by a public safety agency.
9-1-1 Authority
A State, County, Regional, or other governmental entity responsible for 9-1-1 service operations. For example, this could be a county/parish or other local government, a special 9-1-1 or Emergency Communications District, a Council of Governments, or other similar body.
9-1-1 Map Display
The part of the Human Machine Interface (HMI) that displays emergency event location and calling device location information on a map.
9-1-1 Service Area
The geographic area that has been granted authority by a state or local governmental body to provide 9-1-1 service.
9-1-1 System
The set of network, software applications, databases, components and operations & management procedures required to provide 9-1-1 service. This may include commercial, governmental and human resources.
A-GPS
(Assisted-Global Positioning System) is a system that often significantly improves the startup performance—i.e., time-to-first-fix (TTFF)—of a GPS satellite-based positioning system. A-GPS is extensively used with GPS-capable cellular phones, as its development was accelerated by the U.S. FCC’s 9-1-1 requirement to make cell phone location data available to emergency call dispatchers.
AACN
(Advanced Automatic Collision Notification) is an emergency call placed by a vehicle, initiated either automatically or manually, conveying telematics data. “Advanced” indicates that the call carries advanced telematics data such as information about a crash, rollover, fire, other incidents, vehicle description, location, etc.
aka Telematics Call
ACN
(Automatic Collision Notification)
The same as AACN but without the advanced aspects.
NG-AACN
(Next-Generation AACN) An AACN call using NG9-1-1 and conveying the data in the call set-up so the call can be identified as an AACN during routing and call handling, and the data may be available to call handling equipment and a call taker immediately.
Abandoned Call
An emergency Call in which the caller disconnects before the Call can be answered by the PSAP (Public Safety Answering Point).
Access Line
The connection between a customer premises network interface and the Local Exchange Carrier that provides access to the PSTN (Public Switched Telephone Network).
Access Provider
Any organization that arranges for an individual or an organization to have access to the Internet.
ACD
(Automatic Call Distributor) is equipment that automatically distributes incoming calls to available PSAP attendants in the order the calls are received or queues calls until an attendant becomes available.
ACL
(Access Control List) is a security mechanism used to allow or deny access to either computing or networking systems (e.g., access through a firewall).
Acoustic Coupler
An interface device for converting electrical signals to auditory signals and vice-versa, usually into and out of a traditional telephone handset. It consists of rubber cups that hold the telephone handset on a TTY device.
Americans with Disabilities Act (ADA)
Federal Legislation passed into law on July 26, 1990, prohibiting discrimination based on disabilities. It is a landmark civil rights law that identifies and prohibits discrimination based on disability in employment, state and local government, public accommodations, commercial facilities, transportation, and telecommunications. This Act requires all Public Safety Answering Points (PSAPs) to provide direct and equal access to emergency telephone services for people with disabilities who use teletypewriters (TTY/TDDs), also known as telecommunications devices for the deaf. This means that the personnel answering calls at the PSAP level must be able to receive TTY/TDD calls directly and must be able to engage in TTY/TDD conversation.
Additional Data
Further describe the nature of how the call was placed, the person(s) associated with the device placing the call, or the location the call was placed from. There are three types of Additional Data:
Additional Data for the Call
Additional Data for the Caller
Additional Data for the Location
Address Types
Civic Address - Any city-style address with a house number and a street name.
Postal Address - Address recognized and used by the USPS (United States Postal Service) for delivery of mail.
Service Address - The physical location of a (static) subscriber access line.
Sub address - A component of a Civic Address that provides differentiation between features having a common street name and address number.
ADM
NENA Administrative (ADM) documents describe the organizational structure of the association and its committees, establish the processes for document development and approval, and provide the appropriate forms to document committee work. ADM documents are developed and maintained by the Development Group Administrative Committee’s Document Management Working Group and approved by the DSC and NENA Board.
Administrative ESN
(Emergency Services Number) - A 3-5 digit number that represents an ESZ (Emergency Service Zone). It is stored in the MSAG (Master Street Address Guide) and is returned from an ALI (Automatic Location Identification) query. The Administrative ESN facilitates dispatching of the proper emergency service agency(ies). An Administrative ESN is assigned to each MSAG range to associate the physical addresses to an ESZ. It is used to display English Language Translations (ELT) and may be used by CPE (Customer Premises Equipment) to transfer calls to the correct responder. An Administrative ESN may not be the same as a routing ESN (Refer to Routing ESN)
ADR
(Additional Data Repository) is a data retrieval facility for Additional Data. The ADR dereferences a URI passed in a Call-Info header field or PIDF-LO <provided-by> and returns an Additional Data object block. An Identity-Searchable Additional Data Repository (IS-ADR) returns Additional Data associated with an identity.</provided-by>
AES
(Advanced Encryption Standard) is a FIPS (Federal Information Processing Standard)-approved cryptographic algorithm that is used to protect electronic data.
AFLT
(Advanced Forward Link Trilateration) is a type of handset-based position location technology. Unlike A-GPS, AFLT does not use GPS satellites to determine location. To determine location, the phone takes measurements of signals from nearby cellular base stations (towers) and reports the time/distance readings back to the network, which are then used to triangulate an approximate location of the handset. In general, at least three surrounding base stations are required to get an optimal position fix.
Agency
An entity with a valid public safety purpose under a single discrete recognized administration.
In 9-1-1 and public safety operations, an Agency is a governmental entity, or a non-governmental entity under the direction of a governmental entity, responsible for all or some part of 9-1-1 system provisioning, call processing, and field response.
In NG9-1-1, a governmental Agency is recognized through validating an enabling statute, ordinance, municipal incorporation, joint powers agreement, or similar. A private entity is recognized through validating articles of incorporation, business registration, or similar. A validated Agency will have a unique Agency Identifier and will be issued an Agency Certificate. The Agency Certificate can validate Agents that are members of that Agency.
The Agency provisioned in the NG9-1-1 environment that holds an Agency Certificate may not necessarily be the same Agency recognized in 9-1-1 and public safety operations, depending on how the NG9-1-1 system is designed and configured.
Agency Identifier
A domain name for an agency used as a globally unique identifier.
Agent
An authorized person — employee, contractor, or volunteer — who has one or more authorized functions in, or as directed by, an Agency.
In NG9-1-1, an Agent is validated by its parent Agency. The fact that the Agent’s Certificate Signing Request is signed by the parent Agency’s Agency Certificate constitutes validation of that Agent. A validated Agent will have a unique Agent Identifier and will be issued an Agent Certificate. An Agent in NG9-1-1 can also be an automaton in some circumstances (e.g., an IMR answering a call). The Agent Certificate will enumerate the Role(s) of the Agent.
AIP
(Access Infrastructure Provider) is the entity providing physical communications access to the subscriber. This access may be provided over telco wire, CATV cable, wireless or other media. Usually, this term is applied to purveyors of broadband internet access but is not exclusive to them.
ALE
(Access Location Entity) is a network entity or function that provides network measurements to a LIS allowing the LIS to correlate a device with a physical location.
ALI
(Automatic Location Identification) is the automatic display at the PSAP of the caller’s telephone number, the address/location of the telephone and supplementary emergency services information of the location from which a call originates.
ALRS
(Agency Locator Record Store) is a web service that, when presented with an agency locator URI, returns the agency locator record.
Alternate Address Record
The Postal equivalent to the MSAG or any other alternate address required (i.e., an alias street name – John Carpenter Freeway vs. Highway 121).
Alternate Routing
The capability of routing 9-1-1 calls to a designated alternate location(s) if all 9-1-1 trunks are busy or out of service. May be activated upon request or automatically, if detectable, when 9-1-1 equipment fails or the PSAP itself is disabled.
ANI
(Automatic Number Identification) is the telephone number associated with the call origination, originally associated with the access line of the caller.
ANI Controller
A stand-alone CPE component that provides the ANI decoding and function key control for 9-1-1 service.
ANI II Digits
Digits in the Enhanced MF Signaling protocol that indicate to the PSAP CPE ANI display device whether the display should remain steady or flash, or if the call is a test call.
pANI
(Pseudo Automatic Number Identification), Routing Number
A telephone number used to support routing of wireless 9‑1‑1 calls. It may identify a wireless cell, cell sector or PSAP to which the call should be routed.
ANS
(American National Standard) is a standard document accredited by ANSI (American National Standards Institute).
ANSI
(American National Standards Institute) is an entity that coordinates the development and use of voluntary consensus standards in the United States and represents the needs and views of U.S. stakeholders in standardization forums around the globe.
ANSI BSR
(Board of Standards Review) is responsible for the approval and withdrawal of American National Standards.
Answering Position
The workstation at which 9-1-1 calls are answered and responded to by the Telecommunicator.
AOA
(Angle of Arrival) is a terrestrial Location Determination Technology (LDT) that computes a transmitter’s location based upon the angle at which the transmitter’s radio signal strikes multiple receivers.
APCO
(Association of Public Safety Communications Officials) is the world’s oldest and largest not-for-profit professional organization dedicated to the enhancement of public safety communications.
API
(Application Programming Interface) is a set of routines, protocols, and tools for building software applications. The API specifies how software components should interact and APIs may be used when programming GUI (Graphical User Interface) components.
AQS
(ALI Query Service) is the NENA XML schema that defines the ALI interface between the ALI Database and the PSAP.
ASL
(American Sign Language) is a natural visual-spatial language which is governed by complex linguistic rules and parameters that are distinct from spoken and written languages. It is most commonly used by the Deaf community in the United States and parts of Canada.
ASL Gloss
(American Sign Language Gloss) is a simplified notational system used to transcribe American Sign Language into another language. This is most often used in settings where video is not available. American Sign Language does not have a written form and glossing should not be taken as such.
ASN
(Autonomous System Number) is a unique globally available number used to identify an autonomous system that enables it to exchange exterior routing information with other neighboring autonomous systems.
ASRR
(Average Sector Radius Range) is the average distance from a point (e.g., cell tower) that scribes an arc depicting a sector under average operating conditions.
ATIS
(Alliance for Telecommunications Industry Solutions) is a U.S.-based organization that is committed to rapidly developing and promoting technical and operations standards for the communications and related information technologies industry worldwide using a pragmatic, flexible and open approach.
Authoring Working Group
The group that approves the content of a NENA document and whose vote (by the group’s eligible voters) demonstrates evidence of consensus.
Authoritative
Definitive, master. Information has an authoritative source, normally the owner of the information or its designee. There is only one authoritative source. A specific element or service may be authoritative for a given implementation or jurisdiction.
Authorized Observer
A Working Group role available to Committee Co-Chairs, DSC Advisors, NENA Staff and Executive Board members who may participate in WGs, but do not have voting rights.
Average Busy Hour
The 1-hour period during the week statistically shown over time to be the hour in which the most telephone calls are received.
AVL
(Automatic Vehicle Location) is a means for determining the geographic location of a vehicle and transmitting this information.
B2BUA
(Back‑to‑Back User Agent) is a SIP element that relays signaling mechanisms while performing some alteration or modification of the messages that would otherwise not be permitted by a proxy server.
A logical entity that receives a request and processes it as a UAS (user agent server). In order to determine how the request should be answered, it acts as a UAC (user agent client) and generates requests. Unlike a proxy server it maintains dialog state and must participate in all requests sent on the dialogs it established.
Basic 9-1-1
An emergency telephone system which automatically connects 9-1-1 callers to a designated answering point. Call routing is determined by originating central office only. Basic 9-1-1 may or may not support ANI and/or ALI.
Baudot Code
A five-bit encoding scheme developed for Telex transmission that represents text, numerals, punctuation and control signals. It is the standard transmission signaling scheme used by TDD/TTY devices.
BCF
(Border Control Function) provides a secure entry into the ESInet for emergency calls presented to the network. The BCF incorporates firewall, admission control, and may include anchoring of session and media as well as other security mechanisms to prevent deliberate or malicious attacks on PSAPs or other entities connected to the ESInet.
BGP
(Border Gateway Protocol) is a protocol designed to exchange routing and reachability information among autonomous systems.
BISACS
(Building Information Services and Control System) is a computer-based system that allows access to building information such as its structural layout and/or monitors a particular building or set of buildings for alerts.
Business Day
A 24-hour period of time beginning at midnight which is established by the Database Management System Providers’ and/or Service Providers’ hours of operation. Business days do not normally include Saturday and Sunday or any Provider’s recognized holidays.
Busy Hour
The hour each day with the greatest emergency call volume at a PSAP.
CAD
(Computer Aided Dispatch) is a computer-based system that aids PSAP Telecommunicators by automating selected dispatching and record-keeping activities.
UCAD
(Unified Computer Aided Dispatch)
A detailed, comprehensive, and unified set of functional requirements for CAD (Computer Aided Dispatch), developed by the IJIS Institute and APCO (Association of Public Safety Communications Officials International).
CALEA
(Commission on Accreditation for Law Enforcement Agencies) was created in 1979 as a credentialing authority through the joint efforts of law enforcement’s major executive associations:
IACP (International Association of Chiefs of Police);
NOBLE (National Organization of Black Law Enforcement Executives);
NSA (National Sheriffs’ Association); and
PERF (Police Executive Research Forum).
The purpose of CALEA’s Accreditation Programs is to improve the delivery of public safety services, primarily by: maintaining a body of standards, developed by public safety practitioners, covering a wide range of up-to-date public safety initiatives; establishing and administering an accreditation process; and recognizing professional excellence.
Call
A generic term referring to any request for public safety assistance, regardless of the media used to make that request.
See also: Call, The - dramedy starring Halle Berry as an unrealistic version of a dispatcher.
NENA’s magazine is also named The Call Magazine.
Call Back
The capability to re-contact the calling party.
Call Handling
A Functional Element concerned with the details of the management of calls. It handles all communication from the caller. It includes the interfaces, devices, and applications the Agents utilize to handle the call.
Call Identifier
A globally unique identifier assigned by the first element in the first ESInet which handles a call.
Call Progress Signals
Audible cues to advise 9-1-1 callers of the status of their call. (e.g. Busy Tone, Reorder Tone)
Call Queuing
The method of selection of which calls get passed to the outgoing trunk group when there are more call originations than terminating members on the outgoing trunk.
Call Relay
Forwarding of pertinent information by a Telecommunicator to the appropriate response agency (not to be confused with Telephone Relay Service).
Call Routing
The function of delivering the 9‑1‑1 call to the appropriate PSAP.
Call Server
Used in the Interim VoIP Architecture For Enhanced 9‑1‑1 Services standard to refer to the entity in a private or public IP domain that provides service to endpoints in an emergency caller’s home domain and that interworks with the SIP servers and other elements in the IP domain used to support emergency services call routing in the i3 solution. The Call Server may use SIP or some other VoIP signaling protocol within its own serving domain.
Call Set-Up Time
In wireline telephony, the amount of time between when a caller dials the last one (1) in 9‑1‑1 and the call is presented to the appropriate PSAP. In wireless and IP telephony, the amount of time between when a caller presses “send” (or equivalent) and the call is presented to the appropriate PSAP.
Calling Party Hold
The capability of the PSAP to maintain control of a 9‑1‑1 caller’s access line, even if the caller hangs up.
CAMA
(Centralized Automated Message Accounting) is a type of in-band analog transmission protocol that transmits telephone numbers via multi-frequency encoding. Originally designed for billing purposes.
CAP
(Common Alerting Protocol) is a general format for exchanging emergency alerts, primarily designed as an interoperability standard for use among warning systems and other emergency information systems.
CAP message
A notification using the Common Alerting Protocol. CAP is used within the ESInet to send alerts from automated systems to PSAPs, and is also used to communicate data between agencies without a call.
Carrier
In the context of 9‑1‑1 database vernacular, a business entity provides a function to a customer base, typically for a fee. Examples of carriers and associated services are; a Local Exchange Carrier providing PSTN service, a VoIP Service Provider providing VoIP service, an Internet Service Provider providing email service.
CAS
Call Associated Signaling
Allows for the device position or location information to be delivered to the emergency services network in the call signaling as part of the call setup information. With Call Associated Signaling, the originating network pushes the position information to an ESNE (Emergency Services Network Entity).
CallPath Associated Signaling
A method for delivery of wireless 9-1-1 calls in which the Mobile Directory Number and other call associated data are passed from the Mobile Switching Center to the PSAP via the voice path.
Channel Associated Signaling
An option for the signaling channel (time slot 16) of an E1 interface; ITU G.704. Used on digital interfaces for signaling.
CDR
(Call Detail Record) is a record stored in a database recording the details of a received or transmitted call. The data information sent to the ALI computer by a remote identifying device (PBX, Call Position Identifier, …)
Cell Sector
One face of a cell site (typically 3-sided) that operates independently of the other sectors.
Cell Site
The location of a cell tower and related equipment.
Centrex
A business telephone service offered by some Local Exchange Carriers that provides PBX type features over access lines.
Centroid
A point within and at the center of the physical extent of a real-world object, as represented in a GIS.
CERT
(Community Emergency Response Team) is a FEMA-sponsored training program to enable local volunteers to assist first responders in disaster response.
Certificate Authority
A trusted entity that issues digital certificates. The Certificate Authority conducts a vetting process to ensure that the digital certificate holder is who they claim to be. Digital certificates are essential to secure communication and are important in the PKI (Public Key Infrastructure).
CGL
(Calling Geodetic Location) is an ISUP parameter that indicates the X/Y coordinates of the calling party.
CHGN
(Charge Number) is a parameter within SS7 and MF signaling to designate the telephone number that would be billed for the call (billing is not applicable to 9‑1‑1 calls).
CHS
(Call Handling System) is a communications software system and equipment used to receive and process Calls.
CID
(Company Identifiers) NENA Company Identifiers (also known as Company IDs or CIDs) allow 9-1-1 centers to quickly identify the telephone company or access infrastructure provider responsible for a particular telephone number.
CID 1
Access Infrastructure Provider ID, Company Identifier (ID) 1, CID 1
A 3-5 character identifier that distinguishes the entity providing voice service (e.g., Wireline, Wireless, VoIP, PBX, etc.) to the end user. The company identifier registry is maintained by NENA in a nationally accessible database
CID 2
Data Provider Company ID, Company Identifier (ID) 2, CID 2
A 3-5 character identifier that distinguishes the source of the ALI record information (e.g., service provider/reseller/private switch owner, or telematics provider).
SPID
(Service Provider Identifier), OCN (Operating Company Number)
A four (4) character, numeric service provider identification code assigned by the NECA (National Exchange Carrier Association) to Local Exchange Carriers. It does not include resellers, private switch owners or others not acting as LEC’s who are sending customer’s transaction record data to the 9-1-1 databases.
cid
(Content Identifier [Content‑ID]) is a unique identifier assigned to a body part that allows the body part to be referenced in a SIP header field.
CIF
(Critical Issues Forum) are periodic events presented as a public service, focusing on emerging and significant topics in emergency communications. CIFs typically provide one to three day workshops featuring industry experts.
Circuit-Switched Networks
A type of network in which a physical path is obtained for and dedicated to a single connection between two end points in the network for the duration of the connection. Ordinary voice phone service is circuit-switched.
CISA
(Cybersecurity and Infrastructure Security Agency) is a federal agency that is the Nation’s risk advisor, working with partners to defend against today’s threats and collaborating to build more secure and resilient infrastructure for the future. “CISA Central” replaces the NCCIC (National Cybersecurity and Communications Integration Center).
CISC
(Canadian radio-television and telecommunications commission Interconnection Steering Committee) is the Steering Committee for the CRTC (Canadian Radio-Television and Telecommunications Commission).
CISD
(Critical Incident Stress Debriefing) refers to a structured group discussion, usually provided 1 to 10 days post crisis, and designed to mitigate acute symptoms, assess the need for follow-up and, if possible, provide a sense of post-crisis psychological closure.
CISM
(Critical Incident Stress Management) refers to a team comprised of peers and mental health professionals who train and work together to help personnel through traumatic and/or critical incidents. These teams play a crucial role following a critical incident by providing group defusing and debriefing meetings and coordinated conversations to mitigate stress reactions and provide guidance on coping. CISM Teams may be local, regional, or from different parts of the US, as it is strongly discouraged for peers to debrief their own personnel.
CJIS
(Criminal Justice Information Services) serves as the focal point and central repository for criminal justice information services in the FBI. Programs initially consolidated under the CJIS Division included the NCIC (National Crime Information Center), UCR (Uniform Crime Reporting), and Fingerprint Identification. In addition, responsibility for several ongoing technological initiatives was transferred to the CJIS Division, including the IAFIA (Integrated Automated Fingerprint Identification System), NCIC 2000, and the NIBRS (National Incident-Based Reporting System).
CLDXF
(Civic Location Data Exchange Format) is a United States profile of PIDF‑LO that defines a set of standard data elements that describe detailed street address information.
Client ID
An identifier for an instance of a Location Object (Geo Location, Civic Location or both) that is stored in a LIS.
CLLI
(Common Language Location Identifier) is an identifier used in the North American telecommunications industry to specify the location of equipment. For example, an 8 to 11 character code assigned to a central office to designate the physical location.
CMRS
(Commercial Mobile Radio Service) is a US FCC designation for any carrier or licensee whose wireless network is connected to the public switched telephone network.
CO
(Central Office) The Local Exchange Carrier facility where access lines are connected to switching equipment for connection to the Public Switched Telephone Network.
aka End Office (EO)
Code Point
A code for a requested QoS action used in the Diffserv QoS mechanism on an IP network. The code point is sent in the TOS field of an IP packet.
CODEC
(Coder/DECoder or Compression/DECompression) describes the integrated circuits, or chips that perform data conversion. In this context, the term is an acronym for “coder/decoder.” This type of codec combines analog-to-digital conversion and digital-to-analog conversion functions in a single chip. In personal and business computing applications, the most common use for such a device is in a modem.
Collaboration Functional Element
A Functional Element that provides for collaborative communications among agents, both within and between agencies.
COLT
(Cell On Light Truck) is an area mobile cell site on smaller box trucks and limited with respect to the cell phone network, as opposed to the fully functional COW (cell on wheels).
Common Trunk Group
A trunk group that carries calls that originates from more than one service type or more than one carrier.
aka Shared Trunk Group
Communications Assistant
A general term for person who voices text and types speech (IP Relay or TRS) or who interprets ASL conversation between callers (VRS). “Communications Assistant” supersedes the term “TDD operator”.
Conference Transfer
The capability to bridge a third party onto an existing call.
aka Three-Way Calling
Confidence
In terms of certainty, the mathematically derived statistical estimate indicates how sure the measuring system is that the wireless Phase 2 location data estimate is accurate, within the bounds defined by the Uncertainty value. This is expressed as a percentage, such as 90%, or 45% etc. The specific value is not representative of the accuracy of the PDE locating system.
Uncertainty
The mathematically derived statistical estimate, expressed in meters, indicating the size of the area used in the calculation of Confidence. The specific value IS NOT representative of the accuracy of the PDE locating system.
Congestion Control
A method of controlling traffic when there are insufficient resources to meet demand, for example, more requests for calls than there are trunks. It may be achieved by rejecting requests, and/or diverting calls.
Consensus Body
The group that approves the content of a standard and whose vote demonstrates evidence of consensus. The voting members of the Working Group are deemed to be the Consensus Body for purposes of the document review and approval process. Consensus is documented by a formal approval ballot.
COOP
(Continuity Of Operations Plan) is a plan to ensure that Primary Mission Essential Functions continue to be performed during a wide range of emergencies, including localized acts of nature, accidents and technological or attack-related emergencies.
CoS
(Class of Service) is a designation in E9‑1‑1 that defines the service category of the telephony service. A few examples are residential, business, Centrex, coin, PBX, VoIP and wireless Phase II (WPH2).
Fixed (Static)
VoIP Class of Service sold as not having nomadic capability. Refers to an IP end-point that cannot move, is always in same location and always accesses a network from the same point.
FX (Foreign Exchange) Service
A telephone line switched in an exchange or central office other than the exchange or central office area in which the telephone is located.
COW
(Cell On Wheels) is a mobile cell site that consists of a cellular antenna tower and electronic radio transceiver equipment on a truck or trailer, designed to be part of a cellular network typically on a temporary or short-term basis.
CPE
(Customer Premises Equipment) consists of communications or terminal equipment located in the customer’s facilities – Terminal equipment at a PSAP.
CRDB
(Coordinate Routing Database) is a database where cell site addresses are provisioned. The CRDB provides a translation between a given position expressed in X, Y coordinates, to an ESZ (Emergency Services Zone), by determining the ESZ in which the coordinates are located.
CRM
(Committee Resource Manager) is a NENA staff or contractor position who provides administrative support to the DSC volunteer leadership and to the Process Review Committee (PRC).
CRN
(Contingency Routing Number) is a 24x7 PSAP emergency number, or a routing number associated with a national or default call center.
CRTC
(Canadian Radio-television and Telecommunications Commission) supervises and regulates broadcasting and telecommunications systems in Canada.
CSRIC
(Communications Security, Reliability and Interoperability Council) is an advisory body of the FCC, formerly known as NRIC (Network Reliability and Interoperability Council), which provides recommendations to the FCC to ensure, among other things, optimal security and reliability of communications systems, including telecommunications, media, and public safety.
CTI
(Computer Telephone Integration) is integrating telephone function into a computing device.
CTIA
(Cellular Telephone Industry Association) is an association for the wireless industry.
CTX-IP
(Centrex-based Internet Protocol) is a Telco voice service that provides Internet protocol based private automatic branch exchange or PABX-like features on all lines used by a single customer; the switching equipment is located at the central office and is operated and maintained by the Telco.
DAS
(Distributed Antenna System) is a network used to distribute RF signals from a central hub to a specific area with poor coverage or inadequate capacity.
Data Domain
An enumerated listing or range of valid values that may be used as an attribute. If no Data Domain is provided, then any value that meets the format criteria may be used.
DBMS
(Data Base Management System) is a system of manual procedures and computer programs used to create, store, and update the data required to provide Selective Routing and/or Automatic Location Identification for E9‑1‑1 systems.
DBMSP
(Data Base Management System Provider) is an entity providing Selective Routing (SR) and/or Automatic Location Identification (ALI) data services.
DCE
(Data Communications Equipment) is the designation for RS-232 and EIA/TIA-574 serial communication devices such as modems. DCE (Data Communications Equipment) typically connects to DTE (Data Terminal Equipment).
DCE
(Data Communications Equipment) is the designation for RS-232 and EIA/TIA-574 serial communication devices such as modems. DCE (Data Communications Equipment) typically connects to DTE (Data Terminal Equipment).
Dedicated Trunk
A telephone circuit used for a single purpose; such as transmission of 9-1-1 calls.
Default Routing
The capability to route a 9‑1‑1 call to a designated (default) PSAP when the incoming 9‑1‑1 call cannot be selectively routed due to an ANI failure or other cause.
Default Route
The routing condition that occurs when a 9‑1‑1 call arrives at a switching or routing point with insufficient data to allow normal routing to the correct PSAP.
MSC (Mobile Switching Center) Default Route
The routing condition that occurs when:
a wireless 9-1-1 call arrives at an MSC with insufficient data to allow normal routing to the correct PSAP, or
all dedicated MSC to Selective Router trunks, primary and secondary routes, are out of service (i.e., trunk failure condition).
MSC (Mobile Switching Center) Trunk Alternate Route
The routing condition that occurs when all trunks from the MSC to SR are out of service and calls need to be routed to the PSAP. The scenario represents an MSC to SR trunk failure condition versus an all trunks busy condition.
Delegate Credential Authorities
An entity responsible for issuing certificates derived from Valid Emergency Services Authority (VESA) certification to the operators of network entities that utilize VESA certificates to exchange authenticated data on the i2-defined interfaces. Examples of delegate credential authorities may be PSAP operators, state emergency authorities, or regional 9‑1‑1 service providers.
Demarcation Point
A mutually-defined boundary dividing one area of responsibility from another.
Dereference
The act of exchanging a reference to an item by its value. For example, the dereference operation for location uses a protocol such as SIP or HELD to obtain a location value (PIDF-LO).
DES
(Data Encryption Standard) is a common standard for data encryption and a form of secret key cryptography (SKC), which uses only one key for encryption and decryption. Public key cryptography (PKC) uses two keys (i.e., one for encryption and one for decryption).
Development Committee
A committee in the NENA Development Group (NDG) established to address the complex operations and technology issues related to the provision and management of emergency communications services in specific topical areas.
Diffserv
A quality of service mechanism for IP networks defined by the IETF.
Direct and Equal Access
The ability to TTY calls without relying on an outside relay service or third-party services to communicate with individuals with hearing and speech disabilities regardless of how the communication originated.
Direct Dispatch
The performance of 9‑1‑1 service wherein upon receipt of an emergency call, a PSAP telecommunicator transmits all relevant available information to the appropriate public safety personnel or emergency responders without delay, transfer, relay, or referral.
Discrepancies
Used in NENA documentation, is a term used to describe records that do not match the associated database such as the MSAG database. Such discrepancies are referred to an error file or report for resolution.
Dispatch System
Functional Element used to assign appropriate resources (emergency responders) to an incident, monitor the response and relay relevant information. Tracks and logs all transactions associated with the emergency response.
Diverse Routing
The practice of routing circuits along different physical paths in order to prevent total loss of 9‑1‑1 service in the event of a facility failure.
Diverted Call
Call that was rerouted due to the nominal destination’s unavailability or inability to accept. Calls may be diverted for conditions that are scheduled (e.g., maintenance, hours the PSAP is not staffed, etc.) or for events that cannot be scheduled (e.g., equipment or network failure, disasters, etc.)
Call Diversion
The process that results in a diverted call.
DMZ
(Demilitarized Zone), in computer networks, a physical or logical sub‑network separates an internal local area network (LAN) from other untrusted networks, usually the Internet.
