Ipt Hsc Chapter Comunications

Front 1

Communication system

Back 1

An information system that enables people to send and relieve data

Front 2

Protocol

Back 2

A set of rules that governs the transfer of data between computers

Front 3

Handshaking

Back 3

An agreement on which protocol; to use to accomplish the exchange of information.

Front 4

Speed of transmission

Back 4

The speed of data transmission is determined by the transmitting device and the bandwidth.

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Bandwidth

Back 5

The Bandwidth is the capacity of the channel, or transmission medium.

Front 6

Bits per Second (bps)

Back 6

The maximum number of bits that can be transmitted in one second.

Front 7

Baud rate

Back 7

The maximum number of data symbols or electrical signals that can be transmitted in one second

Front 8

Error Checking

Back 8

When data arrives at its destination it may contain errors. These error must be detected and corrected

Front 9

Parity Checking

Back 9

a method of error checking using an extra bit called a parity bit. It can be odd or even.

Front 10

Checksum

Back 10

An error checking method that counts the bits in a data packet. Data is divided into packets the bits in each packet are counted and sent to the receiver if the number match it is assumed their is no errors

Front 11

Cycle redundancy check (CRC)

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binary numbers in the block are treated as 1. long binary number & divided by a number (CRC-32).The remainder of the division is retained & sent. Receiving computer does the calculation. If both agree
OK is sent,

Front 12

error correction

Back 12

the most common form of error correction is to retransmit the data.

Front 13

Communication settings

Back 13

parameter settings that may be altered to allow computer or peripherals to communicate

Front 14

parameter

Back 14

a variable that is given a constant value for a particular application.

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bits per second (communication setting)

Back 15

The speed of transmission

Front 16

Data bits (communication setting)

Back 16

are the number of bits in each group. usually 7-bit ASCII or 8-bit ASCII

Front 17

Parity (communication setting)

Back 17

whether it contains a parity bit for error detection it can be odd even or none

Front 18

Stop/Start bits (communication setting)

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The number of stop start bit used in asynchronous transmission.The parameter is used to identify each bit

Front 19

Flow control (communication setting)

Back 19

the handshaking protocol such as XON/XOFF

Front 20

Teleconferencing

Back 20

the use electronic transmission to allow a meeting to occur at the same time at different place

Front 21

Audio conferencing (Teleconferencing)

Back 21

A single phone call involving 3 or more people at different locations.

Front 22

Video conferencing (Teleconferencing)

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Allow people at different locations to see video and audio images of each other.

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Advantage of Teleconferencing

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It reduces costs by simulating face-to-face meetings.

Front 24

Messaging system

Back 24

used to send messages to people in different locations who may receive the message at later time.

Front 25

Traditional ways of messaging systems

Back 25

mail
telephone answering machines
fax- sends graphic over telephone line computer may have modern faxes
All of these are still used

Front 26

Electronic mail (email)

Back 26

ending mail electronically. was revolutionized by the invention of the internet. Can be sent around the world in minuets and to anyone who has an email address.

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Email Address

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They are unique and obtained free
have two parts name and domain name separated by the @ symbol

Front 28

Domain name (email address)

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The specific computer or server where the person's emails are stored

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Email message (structure)

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an email has two main parts the header and the body
the header is like an envelope and the sender address is automatically added

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to (email header components)

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the address of the person receiving the mail

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Carbon copy (Cc) (email header components)

Back 31

send message to other people apart from the recipient (optional)

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Blind carbon copy (Bcc)

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send a copy to other people but they cant see who else got it (optional)

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Subject

Back 33

topic of the email or brief description (optional)

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Reply (email)

Back 34

automatically enters return email address and in the subject types Re: whatever subject the original sender named it

Front 35

address book (email)

Back 35

Used to store people emails

Front 36

mailing list (email)

Back 36

mailing list a group of people who may want to receive the same message. e.g. a class at school

Front 37

signature (email)

Back 37

several lines that can be automatically inserted at the bottom of an email.

Front 38

Electrical commerce (e-commerce)

Back 38

is buying or selling goods through the internet. it is a type of communication system

Front 39

List issues with email

Back 39

spam and ant-spam legislation
changing nature of work
spreed of viruses
use of email in court cases

Front 40

EFTPOS(electronic founds transfer at point-of-sales)

Back 40

is a system that allows people to purchase good and services. it electronically transfer money from the costumer to the seller bank

Front 41

Electronic banking

Back 41

allows people to view the bank accounts and transfer money between accounts online

Front 42

issue with electronic banking

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loss of jobs
security
changing nature of work

Front 43

name the 2 way of data transmission

Back 43

parallel transmission
serial transmission

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Parallel transmission

Back 44

transferring data at the same time using separate channel. it is faster but get out of sync easily

Front 45

Serial transmission

Back 45

is transferring data one after another it is slower but less errors. serial transmission can be asynchronous or synchronous

Front 46

Asynchronous transmission

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sending data by identifying each byte with special start/stop bits

Front 47

Synchronous

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all data is sent at the same time and the same number of bytes is sent each second. it is faster and more efficient

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simplex data flow

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the data flow is one direction e.g normal television

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half-duplex data flow

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the data flows both ways but only one way at a time e.g. walkie-talkies

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Full-duplex data flow

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both way at the same time e.g. a phone call

Front 51

Network

Back 51

a number of computer and their peripheral device connected together in some way

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node

Back 52

each device in a network

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terminal

Back 53

a device that send and receives data from anther computer system

Front 54

intelligent terminal/workstations

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a terminal that has both memory and processing capabilities most are called workstations on a network

Front 55

local area network (LANs)

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a network the connect computer with a small geographical are e.g. a building

Front 56

Wide are network (WANs)

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a network that cover thousand of kilometers can use normal phone lines or leased data line

Front 57

network topology

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the physical arrangement of devices in a network

Front 58

Star topology

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has a central computer with each device connected directly to it. the central computer acts like a switch and if it goes down the network goes down. allocate a certain amount of cpu for each user

Front 59

Bus topology

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all the devices are attached to a
direct line called the bus.
nodes listen if the network is clear. If so, a node will transmit. If collision occurs, CSMA/CD Carrier Sense Multiple Access and Collision Detection allows node to re-transmit at later time.

Front 60

ring topology

Back 60

all devices are attached so that the path is the shape of a continuous circle.
each device as a unique address
data flows in one direction, moving from device to device until it arrives at destination
This avoids data collisions
A node transmits when it receives a token, hence, token ring network