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Information processes and technology topic 3-Communication systems
Characteristics of Communication Systems
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A communication system allows its users to send and receive data and information
The framework in which communication systems function is shown in the diagram below, where it represents
Skype/MSN as a communication system.
Network
Interface
Card
Ethernet Cable
Wireless
Functions performed within communication systems to send a message:
 Message creation
 Organisation of packets at the interface between source and transmitter
 Signal generation by the transmitter
 Transmission via a medium
 Synchronising the exchange
 Addressing and routing
 Error detection and correction
 Security and management
All communication systems have five basic components:
1. The data source produces the data to be sent.
2. The transmitter encodes the data into a signal suitable for a transmission' medium.
3. The transmission medium is a channel, such as a cable, in which the signal is~ transmitted to the destination.
The signal may be changed or distorted during transmission.
4. The receiver decodes the signal back into the original data or an approximation! of the data
5. The destination is the receiver of the information.
Protocols in communication:
 A protocol is a set of rules that governs a communication process
 ‘Handshaking’ is the process of establishing a communication link and agreeing on which protocol to use.
 A communications protocol must define the following:
o Rate of transmission (in baud or bps)
o Whether transmission is to be synchronous or asynchronous
o Whether data is to be transmitted in half-duplex or full-duplex mode

Also, protocols can include sophisticated techniques for detecting and recovering from transmission errors and
for encoding and decoding data.
Common protocols:
 TCP/IP: Transmission Control Protocol/Internet Protocol – rules that split data into packets for transfer across
the internet
 HTTP: Hyper Text Transfer Protocol – allow the displaying of files containing hypertext links across a network
 FTP: File Transfer Protocol – the protocol defining the transfer of files over a network or the internet
 SMTP: Simple Mail Transfer Protocol – sending of e-mail messages
 POP: Post Office Protocol – retrieves e-mail messages
 SSL: Secure Sockets Layer – used for encryption of data for secure data transmission
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Information processes and technology topic 3-Communication systems
The client-server architecture:
The client sends a request to the server using its IP address and the
port. The server receives the request and responds using the client IP
address and port.
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The client controls the user interface and application
The server controls access to the network

Advantages:
o Centralised resources; given that the server is the centre of the network, it can manage resources that
are common to all users
o It is possible to remove or add clients without affecting the operation of the network and without the
need for major modification

Disadvantages:
o Client-server networks can become congested and overload the server with requests
o Increased costs due to the technical complexity of the server
TYPES OF CLIENTS
The client controls the user interface and application . Some examples of clients include; web browsers and e-mail
clients.
 Thin clients:
o A thin client - a workstation that does not have the capacity to perform meaningful tasks without a
server. E.g. a thin client is a network computer without a hard disk drive. They are easy to install and
have lower total costs than fat clients.

Fat clients:
o A fat client (or thick client) - a desktop computer connected to a Network that includes a NOS. They
may do their own processing without access to the server. They perform the bulk of the processing in
client/server applications.
o They can handle higher bandwidths; operating systems and software that do not run on thin clients
can run on fat/thick clients as it has its own resources.
Servers
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server – computer that controls access to the network
Some examples of servers include:
o Print servers - control access to printers on the network and queue data waiting to be printed
o Mail servers - receives electronic mail (e-mail) and stores it in the recipient’s mailbox.
o Web servers - stores and distributes web pages. It allows access over port 80 on its IP address.
o File servers- a computer that provides file services to workstations and users. It stores files and
application software.
o Proxy servers - a computer that manages printing tasks.
NOS

NOS(network operating system)- a set of core programs that run on the computer controlling a network. It
organizes the whole network as one. E.g. Microsoft Windows NT, and UNIX. They have features such as:
 Administration – allows the network manager to manage the network users and perform essential tasks
such as backing up the files on the shared network disk drives.
 File management – allows the network users to access and manage their files
 Security – protects the network resources, users and their files from unauthorised access to the network
 Sharing resources – enables users to access shared files and resources (e.g. printers and modems)
 Cross-platform access – provides software that will allow workstations using different operating systems
to connect to the file server.
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Information processes and technology topic 3-Communication systems
Examples of Communication Systems
Teleconferencing systems:
 Teleconferencing (video conferencing) is an alternative to face to face meetings, using electronic hardware and
software such as camera and internet connections to transfer video and audio data. Commonly used for
education and conferencing.

How data is transmitted and received:
o The video and audio data is captured, digitised (by assigning a number -binary code- to each pixel on
the image to represent its colour), transmitted over the internet, and then decoded when received.
Advantages
o Facilitates flexible meeting scheduling
o Achieves worldwide connectivity; thus avoids
expensive travel costs
Disadvantages
o Can be expensive and requires fast processors and
high transmission speeds
o Reduces personal contact; lack of social skills
develop
Messaging systems:
Email:
 Users are able to send text messages and attached files to individuals or groups of people via the internet (e.g.
used in schools to send notices and make appointments).

How data is transmitted and received:
o Use computers to send and receive text messages and attached documents via the internet
Advantages
 Very fast transmission of mail compared to
conventional postal mail
 Capable of transmitting and receiving text,
graphics, sound and video as attachments
Disadvantages
 Viruses, which can be attached to email
messages
 Only available to those who have a computer,
internet connection and email address
Voice mail:
 Voice mail allows transmission of vocal messages between users via telephone systems.
 How data is transmitted and received:
o Audio messages are recorded and then transmitted by telephone system for storage (when someone
is unavailable)
Advantages
 The receiver does not have to be present, and
messages are stored and can then be later
retrieved by the recipient
 No extra hardware needed besides a telephone
Disadvantages
 Voicemail can be viewed as impersonal by
callers
 Only users with a voice mail account can access
its functionality
Voice over internet protocol (VOIP):
 Purpose: To allow voice calls to be made over a broadband internet connection
 Participants: Residential home users, small businesses
 Data/information: Sound waves converted to digital audio signals
 Information technology: Broadband internet connection, computer, VOIP software (for computer-to-computer
connections), microphone, speakers, sound card, modem

How data is transmitted and received:
o Sound waves are recorded by microphone
o The computer compresses it into data packets for transmission over the IP network
o The sending computer places an address on each packet telling the network devices where to send
them
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Information processes and technology topic 3-Communication systems
o
o
o
Inside of each packet is a payload; a voice recording digitally converted
The sending computer sends the packet(s) to a router which directs it to the receiver
The receiving computer decodes the transmission to output sound waves
Advantages
 Except for your normal monthly ISP fee, there is
usually no charge for computer-to-computer
calls, no matter the distance
 VOIP consumes less transmission time
Disadvantages
 Phone conversations can become distorted,
garbled or lost because of transmission errors
(e.g. packet loss)
 Susceptible to worms, viruses and hacking
Other systems dependent on communication technology:
EFTPOS (Electronic Funds Transfer at Point Of Sale):
 EFTPOS is a financial network for processing credit cards, debit cards and ATM transactions at ‘point of sale’.
 How data is transmitted and received:
o Employee swipes card in a magnetic strip reader
o Customer enters password/PIN
o Card details collected and funds transferred from customer to retailer’s account
Advantages:
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Easier than manually transferring funds from
bank branch
Efficient, secure form of payment
Disadvantages:
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Both buyer and the seller have to pay charges
for use of the cards
Many people don’t have bank accounts or
prefer to use cash
Emerging trends
o Pay Pass
o Tap and Go (tap your visa card against the machine and up to $100 can be paid for using it,
E-commerce:
 E-Commerce - consists of the buying and selling of products or services over electronic systems such as the
internet and other computer networks. Can be used with computers, mobile phones, ATMs, telephone, etc.
Advantages
 Customers are more easily able to compare
products and services
 Reduced waiting time as products and services
are more quickly obtained by customers
Disadvantages
 Potential customers may not like having to
reveal their financial and personal information
online
 Fraud, hacking, identity theft, etc.
Electronic banking:
 Internet banking - involves consumers using the Internet to access their bank account and to undertake
banking transactions. They may do account enquiries and the access to the latest rate of interests and
schemes.
Advantages
o Allows people greater convenience in the
process of banking as electronic banking is
available 24/7
o Saves people from going into the bank to
withdraw or deposit money – travel time and
costs
Disadvantages
 Customers may be sucked into phishing scams
where they disclose their private details to
scammers believing them to be the actual bank
 Unauthorised individuals can intercept banking
transactions; gaining access to people’s private
banking details which they can use for criminal
activities such as fraud
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Information processes and technology topic 3-Communication systems
Transmitting and Receiving in Communication Systems
Transmission media
Wired transmission:
Twisted pair
What is it?
Twisted pairs are stiff copper wires
surrounded by insulating material
then encased by a conductor like a
mesh. ELECTRICAL SIGNALS USED.
The twists in the cable reduce
interference/noise during
transmission. They are also called
unshielded twisted pairs. (UTP)
Coaxial pair
Coaxial cables are thick cores
of copper surrounded by
insulating material. The
insulation is enclosed by a
woven mesh. The mesh is
surrounded by a plastic layer
for electrical interference
protection.
Optical fibre cable
Fibre optic cables are very
thin glass strands well
protected by insulation.
Expensive and most
reliable
10Mbps to 1Gbps
2000m
Cost/reliability
Least expensive, least reliable,
Moderate,
Speed
Cable length
Uses
10Mbps, 100 Mbps
100m
A twisted pair is installed to an
ethernet cable (RJ-45) for use to
connect computers in a local area
network (LAN)
10Mbps
185m
Mostly used for Internet
connections and Foxtel (cable
television)
Topologies
Star, ring
Bus
Star, ring
Wireless transmission:
 Microwave:
o Microwaves are extremely high frequency radio waves waves that can be used for data transmission.
o Microwaves are also used by fixed traffic speed cameras, and for radar, which is used by aircraft, ships
and weather forecasters.

Satellite:
o Use microwave signals between the satellite and its ground stations.
o Geostationary object (in space) functioning as a repeater or microwave tower.
o Used for internet connections mainly in remote areas where other internet connections may be
unavailable
o Advantages: carry very high bandwidth over very large distances

Radio waves:
o The two types of radio transmission are ‘line-of-sight’ and ‘wide area spread spectrum’.
 line-of-sight- having a directional antenna in line with another antenna without objects
impeding the signal. Disadvantage = eavesdropping
 wide area spread spectrum- signals jump from one frequency to another. Advantages=
reduces interference and improves security
o Radio waves have the longest wavelengths in the electromagnetic spectrum.
o Radio waves do more than just bring music to your radio; they also carry signals for your television
and mobile phones.

Infrared:
o Infrared light-emitting diodes (LEDs) emit infrared radiation which is focused by a plastic lens into a
narrow beam. The beam is modulated, i.e. switched on and off, to encode the data. The receiving
computers will contain a silicon photodiode which will convert the infrared radiation to an electric
current.
o Wireless signals, mainly used in devices such as remote controls where it is transmission over very
short distances
o Advantages: add devices without cables
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Information processes and technology topic 3-Communication systems
Transmission speed:
 Transmission speed is the time it takes data to travel from the source to the destination. The hardware being
used and the transmission medium will greatly affect this speed. It can be best described in terms of
bandwidth, baudrate and bits per second (bps).
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Bandwidth: The ability of the transmission medium to handle a particular amount of data in a given time; the
higher the bandwidth the more data that can be sent
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Baud rate: A measure of the speed of transmission in a communication medium; measures how many bits per
second a channel can send per second
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Bits per second (bps): A measure of the speed of transmission in communication medium; measures how many
bits of data are transmitted (or received) in one second
Application level protocols:
 HTTP: Hyper Text Transfer Protocol – allow the displaying of files containing hypertext links across a network
 SMTP: Simple Mail Transfer Protocol – sending of e-mail messages
 SSL: Secure Sockets Layer – used for encryption of data for secure data transmission
Communication control and addressing level protocols:
 TCP/IP: Transmission Control Protocol/Internet Protocol – rules that split data into packets for transfer across
the internet

TCP: Responsible for breaking data down into IP packets before they are sent, and for assembling the packets
when they arrive
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IP: Responsible for ‘routing’ each packet to the correct destination
Transmission level protocols:
 Ethernet: The Ethernet protocol allows for bus, star, or tree topologies, depending on the type of cables used
and other factors
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Token ring: A token ring network is local areas network (LAN) in which all computers are connected in a ring or
star topology and a bit (or token) passing scheme is used in order to prevent the collision of data between two
Asynchronous – uses start and stop bits
computers that want to send messages at the same time.
Synchronous – no start/stop bit
Strategies for error detection and error correction:
 Parity:- Parity is the method used to check data in asynchronous transmission, where one character is checked
at a time. The eighth bit of the byte is the parity bit, which is used to check the accuracy of transmission. The
parity checking can be either odd or even.
o When 01010111 are sent, there is an odd parity.
o
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When 01011111 are sent, there is an even parity, thus an error.
Checksum:-- If the 1 digits of a binary code are added they give a total which is called a checksum. The
receiving computer calculates the checksum and compares it to the transmitted checksum, and if they do not
match, an error is detected.
if the total of the bytes is lower than 255, that is the checksum
add all except for the last, divide by 255 if greater, get remainder,
if there’s an error, then the addition of the byte values, divided by 255 gets a different same remainder
o What is the checksum for the message 00000010
 00000010 = 2 (checksum)
Cyclic redundancy check (CRC):- the transmitted data is treated as one large binary sum . The sum is then
divided by a constant and the remainder is sent to the receiver. The receiver then works out the sum of the
transmitted data, divides it by the same constant and compares the remainder with the transmitted data. CRC
has the highest probability of detecting errors.
o TREAT THE MESSAGE AS 1 BIG BINARY. GET THE VALUE AND DIVIDE BY A CONSTANT. THE
REMAINEDER IS THE CRC.
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Information processes and technology topic 3-Communication systems
Network topologies:
Star networks:
Star networks are where one central node (computer or other network device) and
distant nodes are connected along communications lines that radiate as spokes from the
central node.

Advantages:
o Fast; if the central computer is fast
o Non-centralised failure will not cause the entire network to fail
o Multiple nodes can be easily connected
o Files can be simultaneously accessed by multiple nodes

Disadvantages:
o The network operation depends on the functioning of the central
node; hence, the failure of the central node leads to the failure of the
entire network
Bus networks:
Bus networks are where several devices are connected to a single communications
channel.
Ring networks:
Hybrid networks:

Advantages:
o It is easy to handle and implement; only one main line
o Cheaper; no extra hardware is required (such as a central server)
o Easy error detection since there is only one main line and few
connections
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Disadvantages:
o Slow; can perform well only for a limited number of nodes
o If the main line (bus) is broken, transmission will fail
Ring networks are where there is a continuous circle, with nodes around the
circumference.
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Advantages:
o Cheaper, a central server is not required for the management of this
topology
o Easily set up/implemented – using cables

Disadvantages:
o If one node of the ring breaks down or a part of the network is
disconnected, the network will not work
Hybrid networks are where a combination of any two or more of the basic topologies.

Advantages:
o Able to be used where different types of networks are required

Disadvantages:
o Expensive, errors may be hard to detect within the network
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Information processes and technology topic 3-Communication systems
Wireless networks:
Wireless networks are where the data packets are converted into radio
frequencies which travel through the air to the receiving node.
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Advantages:
o Cables aren’t needed to connect the nodes together; portable
applications are available, e.g. laptops, wireless printers, etc.
o Easy to add stations as there are no cables required
Disadvantages:
o Disconnections are more common than with cable connections
o Quality of transmission is not as high as other methods
o Devices which are not Wi-Fi enabled cannot be connected to the
network
o Wireless signal can be intercepted and accessed by hackers
o within the network
Data collisions
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CSMA/CD is used by bus or star topologies when data collides.
When a node needs to put data onto the network it must first 'listen' to the line for a carrier signal. It can
transmit data after it determines that no carrier signal is detected on the network. Since no other device is
transmitting it places it’s on carrier signal onto the line to prevent other nodes from transmitting. If a node
were to detect a carrier signal present it would wait until the signal is turned off.
Network hardware
Hubs:
 Hubs- A multiport device used to connect computers in a local area network. They send data to many locations
at the same time.
 In a network with hubs data Passes network traffic to all devices connected, therefore slowing down the
network.
 They are cheap and use Half duplex transmission, therefore inefficient under high network traffic
Switches:
 Switches- A multi-port device that allows small sections of LANs to connect and switch traffic directly from the
source to the destination. They:
o Transmit to the destination port only
o Enables faster data transmission as it reduces collisions
o Are more expensive and faster
o Limit traffic to a certain node
Routers:
 Router - stores information about its surrounding networks and the paths it can use to access them. They:
 direct data traffic, which is protocol dependent
 Selects the best path on the network to route data (efficient) by reading the packet address and
understanding the network topology
 Enables fast data transmission as it reduces collisions
 Connects different network
Bridges and gateways:
 Bridges - used to connect two LANs together in a simple network topology which use the same protocol to
communicate.

Gateways- devices that provide the ability for one protocol to talk to a different one . They are more complex
than bridges and will translate data in one protocol to another protocol for transmission.
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Information processes and technology topic 3-Communication systems
Network interface cards (NIC):
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NIC- a circuit board that is installed in a slot inside a PC. The NIC is where the network cable plugs into the
computer.
Provides a physical link to a computer network; this connection allows computers to communicate with
servers, as well as other computers on the network.
The job of the NIC is to control the sending, receiving and error checking of all data exchanged between the PC
and the other network devices.
Mobile phones:
 Transmit and receive voice calls via radio waves
Cables:
 Connects communication systems together, allowing for data transmitting and receiving
Wireless access points:
 A wireless access point (WAP) is a device that allows wireless communication devices to connect to a wireless
network. Common hardware devices that connect to a WAP include laptop computers.
Bluetooth devices:
 Bluetooth is a wireless network protocol for exchanging data over short distances (using short length radio
waves) from fixed and mobile devices, creating personal area networks (PANs). Common hardware devices
that connect to Bluetooth include mobile phones to send and receive data.
Backbone link
 Backbone link- typically fibre or high capacity coaxial cable. It is designed to connect central nodes (such as
hubs and switches) and carries a much higher volume of data than UTP or standard coaxial cable. Users would
not normally connect directly to a backbone.
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Information processes and technology topic 3-Communication systems
OSI model
The bottom layers are responsible for transfer of data from one place to another. They include protocols that specify
the type of plugs, the format of data, the method of transmission and error checking.
The top layers examine the exchange of data between application programs. They include protocols that specify file
transfer, passwords and network management.

OSI (Open Systems Interconnection model)- a theoretical model that describes defined layers in a network
operating system. There are 7 layers:
o Layer 7, Application layer- provides the interface for the application programs.
o
Layer 6, Presentation layer-converts formats specific to
system to formats that are generic. It also provides
encryption and compression.
o
Layer 5, Session layer- Facilitates the starting, handling
and ending of connections between nodes. It also
synchronises streams of data.
o
Layer 4, Transport layer-Ensures that reliability and flow
control are ensured by choosing the correct protocols,
e.g. TCP. It also uses port numbers to differentiate
between different applications on the same node. If the
packet/frame fails then the transport will begin resending.
o
Layer 3, Network layer- It provides addressing across the internet. It determines the best path for the
data. The source and destination is added to the packets. It also handles congestion control and
packet sequencing. This includes switching and routing technologies, such as routers and hubs.
o
Layer 2, Data link layer- It translates messages from the Network layer into bits for the Physical layer
to transmit. It also makes sure that there is reliable transfer between 2 nodes, while dealing with
physical addressing.
Layer 1, Physical layer-It sends the data through physically, e.g. electrical impulse, light or radio signal. It provides the
physical means, e.g. twisted cables, cards.
ASCII basics
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A= 65
The remainder goes on the left, then minus that
and divide.
Keep dividing by 2, no remainder = 0, remainder =1
Keep dividing to 1/2, since can’t have fractions, then
It is from bottom to top.
remainder
0 or 1
Internet, intranets and extranets:
 The Internet consists of a worldwide network of computer networks that use the TCP/IP network protocols to
facilitate data transmission and exchange.

An Intranet is a private computer network that uses the protocols of the Internet. An intranet is not accessible
by computers on the outside of the private network.

An Extranet is a private network that uses Internet protocols. It can be viewed as part of a company's intranet
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Information processes and technology topic 3-Communication systems
that is extended to users outside the company, usually via the Internet.
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Information processes and technology topic 3-Communication systems
Other Information Processes in Communication Systems
Collecting:
 A phone is a collection device for the use of voice mail
 An EFTPOS terminal is a collection device for electronic banking
Digital data:
 Digital Data is data that is stored and transmitted in two possible states; each digit can be either on or off,
represented using electrical impulses that are of high or low voltage
 Much of our technology relies on digital data
 Computers use the binary system to store and transmit data, i.e. the digits 1 and 0
Analog data:
 analogue data is represented in a continuous form in which there are many different possibilities
 Analogue data can be represented as a wave
 It is more difficult to handle this type of data as transmitting it accurately involves sending it in its exact form,
and because there are so many more variables it is more easily corrupted.
Processing:
Encoding and decoding analog and digital signals:
 Communication systems use both analog and digital data, for this reason it is often necessary to encode and
decode signals
o Analog data to analog signal - Telephone conversations are the best example here. The system
encodes speech and transmits it from sender to receiver.

o
Digital data to analog signal - A digital device will often have to display data in an analog form for
humans to understand. This will require encoding the 0’s and 1’s.
o
Digital data to digital signal - This form of transmission has both sender and receiver speak the same
language. One computer on a network is able to communicate directly with another computer.
o
Analog data to digital signal - The analog data is encoded to a series of 0’s and 1’s by dividing the
data into two groups across an illogical line.
Real life example- modems
o Modem converts the digital data from your
PC into an analog signal before sending it
through the telephone link - the
modulation step (the 'mo' in modem).
o The modem on the receiving computer
converts the analog data from its
telephone line back into digital before
passing it to the computer - the
demodulation step (the 'dem' in modem).
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Information processes and technology topic 3-Communication systems
Types of modulation
Wave
Amplitude modulation
Description + diagram
 the change of peak of the wave indicates a 0
or 1. A high peak equals an 1.
Frequency modulation

A higher frequency indicates a 1, a lower
frequency indicates a 0.
Phase modulation

A change of phase indicates a o or 1
NRZ-L modulation

Non return to zero level modulation uses a
high voltage to indicate a zero, and an low
voltage to indicate an 1.
NRZ-I modulation

Non return to zero level inverted
modulation uses a high voltage to
indicate a zero, and an zero voltage to
indicate an 1. The polarity of the bit is
reversed when a 1 bit is encountered.
Manchester encoding

Bits are translated depending on the
transitions.
a 0 is indicated by a 0 to 1 transition at
the centre of the bit
a 1 is indicated by a 1 to 0 transition at
the centre of the bit.
(HIGH LOW = zero) (LOW HIGH = 1)
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QAM
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Quadrature Amplitude Modulation
Waves that have specific shape
(amplitude and phase) represent agreed
upon codes.
(duplicate the wave, then take it back
and reduce depending on amplification.
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Information processes and technology topic 3-Communication systems
Formation of data packets:
 A packet is the unit of data that is routed between an origin and a destination on a network
 The structure of a packet depends on the type of packet it is and on the protocol. Normally, a packet has a
header and a payload
 For example, an IP packet includes;
o The source IP address
o The destination IP address
o The sequence number of the packets
o The type of service, etc.
o The payload is the data it carries
Routing:
 Routing is the process of selecting paths in a network along which to send network traffic
 Routing is performed for many kinds of networks
Encryption and decryption:
 Encryption is the process of transforming information (referred to as plaintext) using an algorithm (called
cipher) to make it unreadable to anyone except those possessing special knowledge, who obtain the ‘key’.

Decryption is the reverse process where the receiver requires the ‘key’ to decrypt the data.
Error checking:
 Parity bit check
 Check sum
 Cyclic redundancy check (CRC)
Displaying:
 A phone is also a display device for the use of voice mail
 An EFTPOS terminal is also a display device for electronic banking
Network administration tasks:
 Adding/removing users
 Assigning users to printers
 Giving users file access rights
 Installation of software and sharing with users
 Client installation and protocol assignment
 Network-based applications
 Logon and logoff procedures
o Where user enters username and password to validate access. A user session is opened and the user
can access resources they have rights to.
o Log-off disconnects that user form network – important for security as open network can be used by
unauthorised users
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Information processes and technology topic 3-Communication systems
Issues Related to Communication Systems
Teleconferencing systems:
 Changing the nature of work as individuals around the world can work on a project and share information
 May lose interpersonal skills as communication via microphones and speakers
Messaging systems:
 Cyber bullying
 Misinterpretation (may not understand abbreviation, cannot see facial expressions)
 Privacy
o Employers have rights to read employee emails sent from work
o Social networking companies may sell user information without user’s knowledge
 Child grooming for sexual assault (using fake Facebook accounts)
 Diminishing of interpersonal skills
E-commerce:
 Hacking
 Loss of jobs as machine replace humans
 Globalisation: access to unreliable sellers – loss of money
Electronic banking:
 Jobs and bank branches close as ATM machines replace bank tellers
 Extra costs for businesses who need to train staff in IT
 E-crime more common (phishing scams, key logging)
EFTPOS:
 Similar to e-commerce
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Information processes and technology topic 3-Communication systems
Changing nature of work (working from home):
Advantages:
 Flexibility over when to work when productivity is high and when it suits private life (taking care of children)
 Save costs on travel
 Allows disabled and rural workers to find jobs
 Reduced office needs for employers
Disadvantages:
 Need self-motivated staff who can cope with isolation
Virtual communities:
 Network of individuals who pursue similar interests; e.g. forums created in Facebook and online dating sites
 Advantages:
o People from around the world can communicate
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Disadvantages:
o Young people can become addicted
o Loss of social skills
The Internet:
The need for ethical behaviour when using the internet
 Do not attack others through insulting messages – cyber bullying
 Do not copy and paste information without proper referencing – plagiarism
 Do not impersonate others to extract personal data – follow netiquette
These behaviours make the internet safe and enjoyable for everyone.
Issues that have arisen from internet use
 Availability of material normally restricted
o Internet saturated with pornography and children with internet access can easily view sites if no filter
(leading to sexualisation of children)
o Internet used to spread child pornography in file sharing sites (abuse of children)
o Australian Government implementing a mandatory filter: will this restrict material that is legally
available
Domination of content and control of access to internet
 Previously, large media organisations decided what news people would receive. But individuals have greater
control and power through blogs – where they can report news.
 Access to internet controlled by a few large companies. There is less competition, leading to higher internet
prices, which limits access to the poor.
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Information processes and technology topic 3-Communication systems
Current and emerging trends in communications
Blogs:
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Wikis:
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BLOGS- a web page that serves as a publically, accessible personal journal for an individual.
Other users can read; entries are dated & have a journal design.
Only updated by blog owner.
Current and emerging trends are:
o Interactive blogs
o Blogs in education
o Group blogs are now possible
A Wiki is a piece of server software that allows users to freely create and edit Web page content using any
Web browser.
Can be updated by any internet user with a wiki account
Powerful educational resource – but the information may not be accurate
RSS feeds:
 RSS FEEDS- A format for delivering regularly changing web content.
 A user subscribes to a feed by entering the users URL by clicking on the feed icon in a browser that activates
the subscription process. It allows the users to avoid manually inspect which feeds they want to read.
Podcasts:
 Podcasts are audio files that deliver content over the Internet
 Users subscribe for podcasts through specific software. It may be on the internet and users will be notified
through email or the software.
 They can be uploaded for download or streamed direct from the site.
Online radio
 Internet Radio is an audio service transmitted via the internet.
 It involves streaming media, giving listeners a continuous stream of audio that cannot be paused or replayed.
 Audio data is transmitted serially over the local network or internet in TCP or UDP packets.
TV and video on demand
 Video on Demand - where a user has access to the companies video database and from there, is able to make
a selection appropriate to their needs.
 The downside of VOD is the large file size that the videos have, this impedes on the speed of the transfer and
consumes the users downloads (assuming they are on a capped plan)
4G
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4G as the name implies, is the fourth generation in the mobile networking standard with speeds up to 1gpbs.
The fourth generation of mobile networking technology requires new hardware to support newer features.
This includes:
o Gaming and high demand services like video conferencing and streaming.
o All prior features in 1G, 2G, and 3G
o up to 30x faster than initial 3G speeds
4G also utilises packet switching telephony only which means packets do not need to be routed, improving
reliability and efficiency.
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Information processes and technology topic 3-Communication systems
3G technologies for mobile communications
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3G refers to the Third Generation of mobile telephone technology.
3G technology is intended for the true multimedia cell phone - usually called smartphones.
3G has the following enhancements over 2.5G and previous networks:
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Several times higher data speed
Enhanced audio and video streaming
Video-conferencing support Web and WAP browsing at higher speeds
IPTV (TV through the Internet) support.
3G application services include mobile internet access, wide-area voice calls, mobile TV and video calls, all in a mobile
environment.
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