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