911 OperTions

Question 1

FCC

Answer 1

Federal Communications Commission

Question 2

Radio Waves

Answer 2

Fundamentally electromagnetic waves that travel through the atmosphere.

Question 3

VLF

Answer 3

Very-low frequency

10 to 30 kHz

Question 4

LF

Answer 4

Low Frequencies

30 to 300 kHz

Question 5

MF

Answer 5

Medium frequencies

300 to 3000 kHz

Question 6

HF

Answer 6

High frequencies

3 to 30 MHz

Question 7

VHF

Answer 7

Very high frequencies

30 to 300 MHz

Question 8

UHF

Answer 8

Ultra high frequencies
300 to 3000 MHz
Traditionally do not carry as far as lower frequencies but do penetrate structures better.
Generally can not communicate at distances greater than 25 miles.

Question 9

SHF

Answer 9

Super high frequencies

3 to 30 GHz

Question 10

EHF

Answer 10

Extremely high frequencies

30 to 300 GHz

Question 11

Trunked Radio

Answer 11

A method used to conserve radio spectrum.
In a trunked radio environment, all users share the same radio frequencies.
The channel switching is controlled by the software.

Question 12

Conventional Radio

Answer 12

The channel switching is manually controlled by the user

Question 13

Simplex Radio System

Answer 13

A basic radio system that transmits and receives on the same frequency.

Question 14

Repeater System

Answer 14

Allows portable and mobile users to hear other users a great distance away.

Question 15

Talk Around

Answer 15

Most portable or mobile equipment can be programmed with a simplex channel that uses the base stations transmit frequency.

Allowing the user to communicate with others without using the repeater.

The radio can only talk to those in a very limited area due to power, antenna, etc.

Question 16

Satellite Receiver

Answer 16

Like repeater stations, satellite receivers are placed strategically throughout the required coverage are.

Question 17

Simulcast System

Answer 17

Transmits the message over more than one transmitter on the same frequency.

Question 18

Analog System

Answer 18

Uses the voices vibrations to send the voice to the transmitter.

Question 19

Digital system

Answer 19

The voice is converted to a digital signal using a voice coder or “vocoder”.

Question 20

P25

Answer 20

Primary objective is to enhance public safety voice communications interoperability through use of and open radio frequency interface subsystem to facilitate the ability to communicate between systems and equipment from different manufacturers.

Question 21

GPS

Answer 21

Global Positioning System

The system relies on 24 satellites orbiting at over approximately 12600 miles out to serve as reference points for ground receivers.

Question 22

DGPS

Answer 22

Differential Global Positioning System.

Relies on a calculation from a second terrestrial receiver at a known fixed location to the satellite and then compares it to the first calculation to determine the error in the signal.

Question 23

AGPS

Answer 23

Assisted Global Positioning System

A-GPS is the handset-based location determination method used in wireless networks today to acquire the location of a 911 caller.

Question 24

U-TDOA

Answer 24

Uplink Time Difference of Arrival

The predominant network based location technology used for wireless 911 call.

U-TDOA determines location based on the time it takes a signal to travel from a mobile phone to each of the sensitive receivers called LMU’s.

Question 25

LMU’s

Answer 25

Location measurement units

Question 26

Local Exchange

Answer 26

Refers to the service area provided by an end office.

Question 27

Exchange area

Answer 27

Refers to the geographic area in which charges and services are uniform.

Question 28

Local loop

Answer 28

Refers to the wires that run from the subscribers PBX, telephone, or key telephone system back to the serving central office.

Question 29

Switching

Answer 29

Switching is the process of connecting the calling party to the called party without the use of dedicated transport facilities.

Question 30

Central Office or CO

Answer 30

Usually refers to a local switching system that connects lines (from subscribers) and trunks and sometimes refers to a telecommunications service provider building in which switching system and telephone equipment are installed.

A central office is where the subscribers lines are joined to the telecommunications service provider switching equipment for the purpose of connecting to other subscribers locally and over long distance.

Question 31

End Office or Class 5 Office

Answer 31

A switching system within a local access and transport area or market area where customer lines are terminated for purposes of interconnection to each other and to trunks.

Question 32

Access Tandem

Answer 32

A switching system that provides traffic concentration and distributes calls between end offices or to an inter exchange carrier.

Question 33

Facility or facilities

Answer 33

Is an all encompassing term used by telephone companies that can apply to any one of the elements of physical telephone plant that is required to provide service.

Question 34

VoIP

Answer 34

Voice over internet protocol

Is an internet protocol telephony term for a set of capabilities used to manage the delivery of voice information over the internet.

Question 35

VSP

Answer 35

VoIP service provider

Question 36

CMRS

Answer 36

Commercial mobile radio services.

Also known as wireless service provider, is an FCC term for any carrier or licensed whose wireless network is connected to the PSTN.