Chap 10 Flashcards
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Numerous applications depend on communication
systems, including
– Texting.
– E-mail.
– Videoconferencing
Wireless Connections
Wireless connections do not use a solid substance to
connect; uses the air itself. Most use radio waves to
communicate
Cellular radio
Use multiple antennae to
communication
a form of broadcast radio that is in wide use for mobile
communications
Bluetooth (short-range).
Radio communication
standard.
Broadcast radio
a wireless transmission medium that distributes
radio signals through the air over long distances
Wi-Fi (wireless fidelity)
Uses high frequency radio
Microwave.
Uses high frequency radio
wave signals.
WiMax (extends Wi-Fi)
New standard that uses microwave
to extend WiFi.
Satellite.
Uses satellites as microwave relay
stations.
a space station that receives microwave signals from an earth-based station, amplifies it, and broadcasts the signal over a wide area to any number of earth-based stations
GPS.
Determine geographic location of
the devices.
Infrared
Use infrared light wants to
communication over short
distances.
Physical Connections
Telephone lines.
* Ethernet cables.
Coaxial cable: single solid copper core.
* Cable TV.
Fiber-optic cable: tiny glass tubes.
* Faster and more reliable than coax.
* Speeds as high as 1 petabit per second.
Types of signals
Analog (telephone).
* Digital (computer)
Transfer rates
- Mbps – million bits per second.
- Gbps – billion bits per second.
- Tbps – trillion bits per second.
- Speed in which modems transfer data.
- Usually measured in megabits per second (Mbps).
Modem
modulator-demodulator.
* Modulation is the process of converting from digital to analog.
* Demodulation is the process of converting from analog to digital.
Types of Modems
Digital subscriber line (DSL).
* High speed telephone lines.
Cable.
* Uses coaxial cable.
Wireless.
* Also known as WWAN
Fourth Generation 4G
increased
speed, streaming video and music.
Fifth Generation 5G,
speeds approaching those of a home
Internet connection
Digital subscriber line (DSL)
- Uses phone lines.
- ADSL is most widely used
type of DSL.
Fiber Optic Service (FiOS)
New technology.
* Google and Verizon
Cable.
- Uses existing TV cable.
- Faster than DSL
Satellite connection
services.
Use almost anywhere.
A network
a collection of computers and devices
connected together via communications devices and
transmission media
Advantages of a network include:
Facilitating communications
– Sharing hardware
– Sharing data and information
– Sharing software
– Transferring funds
A local area network (LAN)
a network that
connects computers and devices in a limited
geographical area
wireless LAN (WLAN)
a LAN that uses no physical wires
A metropolitan area network (MAN)
connects LANs in a metropolitan area
wide area network (WAN)
a network that covers a large geographic area
personal area network (PAN)
a network that connects computers and devices in an individual’s workspace using wired and wireless technology
network architecture
Network Topology.
– Physical arrangement of the network.
* Network Strategy.
– How the information and resources are shared
Client/Server Network.
- Central computers
coordinate and supply
services to other nodes
on the network. - Server provides access
Types of Network
Ring
Star
Tree
Mesh
Peer-to-Peer (P2P) Network
- All nodes have equal authority.
- Can act as both client and server.
Communications software
Help users establish a connection to another computer, mobile device, or network
– Manage the transmission of data, instructions, and
information
– Provide an interface for users to communicate with one another
Ethernet
network standard that specifies no
central computer or device on the network (nodes)
should control when data can be transmitted
token ring
standard specifies that computers and
devices on the network share or pass a special signal
(token)
TCP/IP
a network protocol that defines how messages (data) are routed from one end of a network
to another
LTE
network standard that defines how high-speed cellular
transmissions use broadcast radio to transmit data for mobile communications
Bluetooth
network protocol that defines how two Bluetooth devices use short-range radio waves to transmit data
UWB (ultra-wideband)
network standard that specifies how two
UWB devices use short-range radio waves to communicate at high speeds with each other
IrDA
transmits data wirelessly via infrared (IR) light waves
RFID
a protocol that defines how a network uses radio signals to communicate with a tag placed in or attached to an object, an animal, or a person
NFC (near field communication)
a protocol, based on RFID, that defines
how a network uses close-range radio signals to communicate between two devices or objects equipped with NFC technology
A broadband modem
sends and receives data and
information to and from a digital line
– Cable modem
– DSL modem
A wireless access point (WAP)
a central communications device that
allows computers and devices to transfer data wirelessly among themselves or to a wired network
routers provide additional functionality:
– Wireless router
– Broadband router
– Broadband wireless
router
– Mobile broadband
wireless router
A network card
enables a computer or device that does
not have built-in networking capability to access a
network
Intranet.
- Private network within an organization.
- Works like the Internet.
Extranet.
Private network that connects more than one organization.
* Works like the Internet, but provides suppliers and other
trusted partners with limited access to the organization’s
networks.
Firewall.
Hardware and software that controls access to network.
* Proxy server provides pass-through access.
* Protects against external threats.
Intrusion detection system (IDS).
Works with firewall to protect organization’s network.
* Analyzes all incoming and outgoing network traffic.
Virtual private network (VPN).
- Creates a secure private network connection between your computer
and the organization.
Broadband media
transmit multiple signals simultaneously
bandwidth
The amount of data, instructions, and information that
can travel over transmission media
Latency
time it takes a signal to travel from one
location to another on a network
