2.3 Telecommunications Network Flashcards
_ generally refer to all types of long-distance communication
Telecommunications
_ is the exchange of information in any form over networks.
Telecommunications
_ is a subset of telecommunications and is achieved through the use of telecommunication technologies.
Data communications
_ is a collection of compatible hardware and software arranged to communicate information from one location to another.
Telecommunications system
Telecommunications systems have two sides: the _ and the _.
transmitter, receiver
The major components of a telecommunications systems are:
Hardware, Communications media, Communications networks, Communications processors, Communications software, Data communications providers, Communications protocols, Communications applications.
_— all types of computers and communications processors.
Hardware
_— the physical media through which electronic signals are transferred.
Communications media
_— the linkages among computers and communications devices.
Communications networks
_— devices that perform specialized data communication functions; includes front-end processors, controllers, multiplexors and modems
Communications processors
_—software that controls the telecommunications system and the entire transmission process.
Communications software
_— regulated utilities or private firms that provide data communications services.
Data communications providers
_—the rules for transferring information across the system.
Communications protocols
_— electronic data interchange (EDI), teleconferencing, videoconferencing, e-mail, facsimile, electronic funds transfer, and others.
Communications applications
To transmit and receive information, a telecommunications system must perform the following separate functions that are transparent to the user:
Transmit information.
Establish the interface between the sender and the receiver.
Route messages along the most efficient paths.
Process the information to ensure that the right message gets to the right
receiver.
Check the message for errors and rearrange the format if necessary.
Convert messages from one speed to that of another communications
line or from one format to another.
Control the flow of information by routing messages, polling receivers,
and maintaining information about the network.
Secure the information at all times.
Telecommunications media can carry _ basic types of signals:
two, analog and digital
_ are continuous waves that “carry” information by altering the amplitude and frequency of the waves.
Analog signals
Sound is _ and travels to our ears in the form of waves.
analog
The greater the height (_) of the waves, the _ the sound.
amplitude, louder
the more closely packed the waves
(higher _), the _ the pitch.
frequency, higher
Radio, telephones, and recording equipment historically transmitted and received _ signals, but they are rapidly changing to _ signals.
analog, digital
_ are discrete on-off pulses that convey information in terms of 1’s and 0’s, just like the central processing unit in computers.
Digital signals
T/F
Analog signals have several advantages over digital signals.
False, it’s the other way around
T/F
First, analog signals tend to be less affected by interference or “noise.”
False, it’s digital signals
_ (e.g., “_”) can seriously alter the information carrying characteristics of analog signals, whereas it is generally easier, in spite of noise, to distinguish between an “on” and an “off.”
Noise, static
_ can be repeatedly strengthened over long distances, minimizing the effect of any noise.
Digital signals
_ are hardware devices that support data transmission and reception across a telecommunications system.
Communications processors
Examples of communications processors
Modems, multiplexers, front-end processors, and concentrators
_ - is a communications device that converts a computer’s digital signals to analog signals before they are transmitted over standard telephone lines.
Modem
The public telephone system (called POTS for “Plain Old Telephone Service”) was designed as an _ network to carry voice signals or sounds in an _ wave format.
analog
The conversion from digital to analog is called _, and the reverse is _.
modulation, demodulation
The device that performs modulation and demodulation is called a _; a contraction of the terms modulate/ demodulate.
modem
T/F
Modems are always used in pairs.
True
To take advantage of telecommunications, Ethio-telecom is installing _ advanced across all regions.
4G LTE
_ are terminals (inputs used to transmit and receive data), telecom processors (devices that perform control and provide support function), telecom channels (media for transmission of information), various computer and telecom control software (programs that control telecom activities).
Telecommunications network components
