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Unit 4 : Communication Technologies - Coggle Diagram
Unit 4 : Communication Technologies
Digital communications
Process in which two or more computers/devices transfer data, instruction and information
Communication involves cables and wires or through air (wireless)
Components needed for successful communications
1.Sender
Device initiates instructions to transmit message
Example
: Someone send message from his/her phone either audio, video, picture or text file
2. Receiver/receiving device
Device accepts the transmission of the message
Example
: A message reach its destination after being sent by the sender which is recei either by computer, mobile phone or others platform
3. Message
Data, information or instruction to be communicated
Can be text, audio, video, pictures, etc
Example
: Data or piece of information which is to be communicated
4. Medium
The physical path where the message travel from sender to receiver
Also known as communication channel
Example
: Data of communication transmit through wires or wireless as for example, twisted pair cable, fiber optic cable, radiowaves or microwaves
5. Protocol
A standard for the sender and receiver devices to communicates with each other
Set of rules that govern communications
Example
: Both people use language that both of them can understand
Network usage
Characteristics
Computer network requires both hardware and software to work
Protocol define how communication are sent and received and allow devices to communicate
Networks
Set of devices (referred to as nodes) connected by communication devices and transmission media
Types of network
Area of coverage
Geographical area that network can reach
PAN: Personal Area Network
Connect computers and computing devices in an individual workspace using wired and wireless technology
Devices can be connected through Bluetooth, Wi-Fi, infrared or cables.
BAN: Body Area Network
A type of PAN that wirelessly connects sensors that are placed on human bodies
Can be worn by, carried by, attached to or implanted in human bodies
Also known as Body Sensor Network (BSN)
Usage
: To monitor health data
LAN: Local Area Network
A network that connects computers and device in a limited geographical area
Each computer or device on the network is called a node and are connected by cable
Can be wired or wireless
Example
: Closely positioned group of building
Wireless LAN
Do not use physical cable
Can communicate with a wired LAN
Computer and devices on a WLAN must have built-in wireless capabilities
MAN: Metropolitan Area Network
A high-speed network that connects LANs in a metropolitan area
Design to extend over entire city
Typically has one or more LANs and WLANs
Covers a small geographical area than WAN
Example
: Company may use MAN to connect LANs in all its offices throughout a city
WAN: Wireless Area Network
Covers a large geographical area using a variety of wired and wireless transmission media
Provides long distance transmission of data over huge geographical areas that may comprise a country, continent or whole world
Consist multiple LANs and MANs connected together
Uses public, leased or privated communication equipment in combinations
Architecture
Configuration of computers, devices and media on a network
Client/server
One or more computers act as server
Server control access to hardware, software and other resources on network
Other computers (clients) on network request services from server
Provides centralized storage areas for programs, data and information
Example
: 10 or more computers, but can connect smaller number of computers
Peer-to-peer
Each computer or device on network
All computers have equal responsibilities and capabilities
Share software, hardware, data, information and other resources with computers and devices on network
Example
: Connects fewer than 10 computers
Network Topology
Arrangement or layout of computers/devices on a network
Ring
A network topology in which
every node has exactly two branches connected
to it
Star
A network topology in which
peripheral nodes are connected to central node
(such as a hub, switch, or router) which
rebroadcast all transmission received from any peripheral node to all peripheral nodes
on network originating node
Bus
A network topology in which there is
a single line
(the bus) to which all nodes are connected and the nodes only to this bus
Tree
A network topology in which nodes are
arranged as a tree
and it
is a generalization
of bus topology
Mesh
A network topology in which there are
at least two nodes with two or more paths between them
The Internet
Characteristic
Internet and World Wide Web are not the same
WWW is a service on the Internet
Short for
INTER
connected
NET
work
Uses
Access information
Send/post messages
Communicate with friends and family
Communication devices, lines
and transmission media
What it is communication devices?
Type of hardware capable of transmitting data, instructions, and information between a sender and receiver through transmission media
Example of communication devices
: Modems, wireless access point, network cards, hubs and switches
Dedicated line
- is a type of always-on physical connection that is established between 2 communications devices
Example of dedicated digital lines:
Cable, Digital Subscriber Line, Fiber to the Premises (FTTP), T-Carrier, Asynchronous Transfer Mode (ATM)
What is transmission media?
Materials or substances that carry communication signal
Types
Physical
Typically within/between buildings and underground
Examples:
a. Twisted pair cable (cooper) b. Coaxial cable (cooper)
c. Fiber- optic cable (glass/plastic)
Wireless
Signal sent through air
Example:
a. Infrared
b. Broadcast radio
c. Cellular radio
d. Microwaves
e. Communication satellites
Communication standards and protocols
To ensure compatibility in moving data between different computers and devices on across networks
Network standard
A guideline that specify:
a. The way computers access the medium to which they are connected
b. The type(s) of medium used
c. The speeds used on different types of networks
d. The type(s) of physical cable and/or wireless technology used
Example:
a. Ethernet
b. Token ring
c. Wireless Fidelity (Wi-Fi)
d. Long Term Evaluation (LTE)
e. Ultra-wideband
f. Infrared Data Association (IrDA)
Network protocol
a. Standard that outlines characteristics of how two devices communicate on a network
b. A protocol defines data format, coding schemes, error handling and data transfer sequences
Examples:
a. Transmission control
b. Protocol/Internet Protocol
c. Bluetooth
d. Radio Frequency Identification (RFID)
e. Near Field Communication (NFC)
Mobile Networks
Types
a. 1G
b. 2G
c. 3G
d. 4G
e. 5G
Based on cellular network
G refer to Generation
