Week 3: Computer Networking

Computer Networking: is a collection of computers and other hardware devices so that network users can share hardware, software, data and they can communicate with each other electronically.

Computer Network:

• Wired vs wireless
• Topology
• Architecture
• Size or coverage area

Types of Network:

• LAN: Local Area Network
• MAN: Metropolitan Area Network
• WAN: Wide Area Network

Network Component:

(i) Host/ End Nodes

• Data sources and data destination
• Personal computers, terminals, workstations, automatic teller machine

(ii) Transmission Media

• Sending electric or signal through specific media
• 2 types of transmission media:-

(iii) Network Electronic Devices

• Control data from sources to destination
• Provide interface between different media transmitter or for different protocol
• Connect multiple network together or connect computer or network to the internet
• Bridges, routers, multiplexers, switches, hubs, gateways, front and processors

(iv) Software/ Application

• The applications at the end nodes normally involves technique and protocols
• Protocols determines the rules and procedure to send data, terminate data, interpret data, present data and control mistakes
• Software-ensure data is delivered at respective destination

(v) Network Architecture Standards & Protocols

• NAS- The blueprint of standards that define how device in a network typically connect and communicate
• Ensure interoperability between various devices and equipment made by different vendors

Week 2: Data Communication

On week 2, we learnt about data communication.

Data Communication:

• takes place between two devices that are directly connected by some form of point-to-point transmission medium.

• transmitted via mediums such as wires, coaxial cables, fibre optic, or radiated electromagnetic waves such as broadcast radio, infrared light, microwaves, and satellites.

Data Transmission

A. Type of Signals

   1. Analog signal

•  represent data with continuous wave

   2. Digital signal

• data represented by only two discrete states: 0 and 1 

B. Transmission Type

1. Parallel transmission: message sent one byte at a time- each bit in the byte taking separate path
2. Serial transmission: data sent one bit at a time- one after another along a single path

   Reconstruction of data after transmitted in serial
   -Synchronous and asynchronous transmission

   -Isochronous transmission
     -data sent at the same time- support some real time applications
     -initial communication between both devices to determine factors needed for data transmission

C. Direction of Transmission

  1. Simplex transmission

• one direction only
• role of transmitter and receiver fixed
• e.g: radio signal

  2. Half-duplex transmission

• 2 direction but not at the same time
• one transmits data to other without interruption
• e.g: walkie-talkie

  3. Full duplex transmission

• transmits data in both direction at the same time
• e.g: telephone

D. Data Compression

Week 1: Introduction to Telecommunications

Communication:
The imparting, conveying or exchange of thought, messages, ideas, knowledge or information by sign and sounds like speech, signals or behavior.

Telecommunication:
-Communication over a long distance
-Transfer of data from transmitter to receiver across distance

Elements of computer and communication technology

1. People :- Professional (programmer, computer engineer)
                 - End user (clerk, teacher)
2. Procedure : Specification of the series of actions, acts or operations which have to be executed
3. Data : Implies a binary, machine-readable representation of information
              - Unit for data : bit, byte, kilobyte, megabyte, gigabyte, terabyte

4. Hardware :- input device
                     - process device
                     - output device
                     - storage device
                     - communication device
5. Software :- Application software
                    - System software
6. Communication : Transmission of data
                               - Conversion of data (analog to digital, digital to analog)