Network Infrastructure
access point (AP)
a device (base station) that connects wireless devices together; usually connected to a wired-network
DSL modem
allows digital communication between networks and computers, requires a digital modem
mobile 1G
analog voice
communication devices
any type of hardware capable of transmitting data, instructions, and information between devices functioning as receiver, transmitter, adaptor, converter, etc.
network device vendors
cisco, juniper, IBM, HP, alcatel-lucent, 3Com
network servers
computers that manage and provide network resources and services to clients; usually have more processing power, memory, and hard disk space than clients
network clients (workstation)
computers that request network resources or services
network
consists of 2 or more "computers" connected together in a way that they can communicate and share resources (e.g. information); collection of computers linked by a transmission medium according to a data-transmission protocol
5G
denotes the next major phase of mobile telecommunications standards; 50 billion connected devices (by 2020) to the internet via mobile networks; network capacity = 10,000 times current network; peak data range = 10 Gbps
mobile 2G
digital voice + simple data
broadcast radio
distributes signals through the air over long distance
node
each computer in a network
ESSID
extended service set ID; a "name" for the AP (e.g. mobilenet)
advantages of clients/servers
facilitate resource sharing, facilitate system backup and improve fault tolerance, enhance security, support more users
mobile 4G LTE
faster and better; richer video content; more connections
hub
hardware that allows computers to share data packets within a network
switch
hardware that forwards and filters between connected cables according to the media access control (MAC) addresses in the packets, forwards frames only to the ports involved in the communication rather than to all connected ports (as hub does)
router
hardware that forwards packets between networks by processing information found in the datagram, can be used to connect networks to one another
repeater
hardware that receives a signal, removes unnecessary noise, regenerates it, and retransmits it at high power so that the signal can cover longer distances without degradation
disadvantages of clients/servers
high cost for servers, need experts to configure and maintain, single point of failure to system
twisted-pair cables
if pair of wires not twisted, electromagnetic noises will affect closer wire more than further one, causing errors
LAN
local area network; a group of computers connected within a building or campus (e.g. computers located on a single floor of building or all computers in small company)
mobile 3G
mobile broadband
cable modem
modem that transmits and receives data over cable television (CATV) network, also called broadband modem (carrying multiple signals)
shielded twisted-pair (STP)
more expensive than UTP but less susceptible to noise
coaxial cable
outer jacket, braided shield, foil shield, dielectric, center conductor
optical fiber cable
provides a high-speed data connection between different parts of a building
microwaves
radio waves providing high speed transmission, used for satellite communication
bluetooth
supports a very short range, approx. 10 meters (33 ft.), relatively low bandwidth (1-3 Mbps.), low manufacturing cost
VoIP
talking to other people over the internet; sending digitized audio signals over the internet
hotspot
the area covered by wireless access points
unshielded twisted-pair (UTP)
typically wrapped inside a plastic cover (for mechanical protection); plastic cover, twisted pairs, insulator, metal
dial-up modem
uses standard phone lines, converts digital information into analog, consists of modulator and a demodulator, can be external or internal
WAN
wide area network; computers of LAN's connected across a distance; can cover small to large distances, using different topologies such as telephone lines, fiber optic cabling, satellite transmissions and microwave transmissions
WLAN
wireless LAN; wi-fi (wireless fidelity); a wireless technology that connects computers without cables
infrared (IR)
wireless transmission media that sends signals using infrared light waves