Communication Networks I Flashcards
process of sharing data, programs and information between two or more computers
communications
concept related to using computer networks to link people and resources
connectivity
widespread use of mobile devices with wireless internet connectivity
wireless revolution
allows individuals to stay connected with one another from almost anywhere at any time
wireless technology
electronic systems that transmit data from one location to another
communication systems
basic elements of a communication system (4)
- Sending and receiving devices.
- Connection devices
- Data transmission specifications
- Communication channel
these are often a computer or specialized communication device
sending and receiving devices
these devices act as an interface between the sending and receving devices and the communication channel
connection devices
these are rules and procedures that coordinate the sending and receiving devices by precisely defining how the message will be sent across the communication channel
data transmission specifications
the actual connecting or transmission medium that carries the message and these channels actually carry the data from one computer to another
communication channels
2 categories of communication channels
wired and wireless
uses a solid medium to connect sending and receiving devices
physical connections
physical connections include:
a. twisted-pair cable
b. coaxial cable
c. fiber-optic cable
consists of pairs of copper wire that are twisted together
twisted-pair cable
high-frequency transmission cable, replaces the multiple wires of telephone lines with a single solid-copper core that has over 80 times the transmission capacity of twister pair
coaxial cable
used to deliver television signals and to connect computers in a network
coaxial cable
are used by telephone lines and ethernet cables
twisted-pair cable
transmit data as pulses of light through tiny tubes of glass
fiber-optic cable
fiber-optic cable is capable of sending/receiving a speed of
1 petabit per second (1 million gigabits)
lighter, faster, and more reliable at transmitting data which is rapidly replacing twisted-pair cable telephone lines
fiber-optic cable
move data through the air by using radio waves
wireless connections
technologies used for wireless connections
bluetooth, Wi-Fi, microwave, WiMax, cellular, satellite connections
short-range radio communication standard that transmits data over short distances of up to approximately 33 feet
bluetooth
widely used for wireless headsets, printer connections, and handheld device
bluetooth
uses high-frequency radio signals to transmit data
Wi-Fi (wireless fidelity)
uses high-frequency radio waves which is sometimes referred to as line-of-sight communication as it only travels in a straight line
microwave
transmitted only over relatively short distance in a straight line
microwave
microwave dishes or antennas will be used for _______________ connections
long distance connection
WiMax is known as
Worldwide Interoperability for Microwave Access
a new standard that extends the range of Wi-Fi networks using microwave connections
WiMax
commonly used by universities and others to extend the capability of existing Wi-Fi networks
WiMax
uses multiple antennae (cell towers) to send and receive data within relatively small geographic regions (cells)
cellular
uses satellites orbiting about 22,000 miles above the earth as microwave relay stations
satellite
most satellites are offered by IntelSat which is known as
International Telecommunication Satellites Consortium
used to send and receive large volumes of data
satellite
term relating to sending data to a satellite
uplink
receiving data from a satellite
downlink
network of satellites owned and managed by the Department of Defense continuously sends location information to earth
Application: Global Positioning
device that use the information to uniquely determine the geographic location of the device
Global Positioning System (GPS)
uses infrared light waves to communicate over short distances
infrared
tv remote control is an example of
infrared
continuous electronic waves
analog
presence or absence of an electronic pulse - the on/off binary signals
digital
modem is also known as
modulator - demodulator
process of convertign digital into analog signal
modulation
process of converting analog into digital signal
demodulation
it enables digital personal computers to communicate across the different media, including telephone wires, cable lines, and radio waves
modems
transfer rate of modems is measured in
megabits per second (Mbps)
uses standard phone lines to create a high-speed connection directly to your phone company’s offices
digital subscriber line (DSL)
uses the same coaxial cable as your television that creates high-speed connections using the system unit’s USB or ethernet port
cable modem
WWAN is known as
Wireless Wide Area Network (Wireless Modem)
connection services include
- Dial-up Services
- Digital Subscriber Line (DSL) Service
- Cable Service
- Fiber - Optic Service (FiOS)
- Satellite Connection Services
- Cellular Service Providers
uses existing telephones and telephone
dial-up services
modems to connect to the internet
dial-up services
provided by telephone companies using existing telephone lines to provide high-speed connections and it is much faster than dial-up
digital subscriber line (DSL) service
provided by cable television companies using their existing television cables
cable service
showing up in some areas, but it is a new technology that provide speeds faster than cable or DSL connections
fiber-optic service (FiOS)
uses satellites to provide wireless connections
satellite connection services
satellite connection services is slower than DSL and cable modem
true
support voice and data transmission to wireless devices using cellular networks
cellular service providers
