Fundamentals of Telematics and Computer Networks
What is Telematics?
Telematics is a scientific and technological discipline arising from the evolution and fusion of telecommunications and computing.
Communication and Transmission Differences
Communication is the process by which information is transmitted from one entity to another. This transmission can be analog or digital.
Basic Elements of a Communication System
A communication system consists of the following elements:
- Message: The information communicated (text, numbers, audio, graphics).
- Transmitter: A device that sends the message (computer, camera, phone).
- Receiver: A device that receives the message (computer monitor).
- Environment: The physical path the message travels (twisted pair cable, coaxial cable, fiber optics, lasers, microwaves).
Local Area Network (LAN) vs. Wide Area Network (WAN)
A Local Area Network (LAN) interconnects computers and peripherals within a limited physical area (e.g., a building or up to 200 meters, potentially 1 kilometer with repeaters).
A Wide Area Network (WAN) covers a larger geographical area, connecting multiple LANs.
Protocol vs. Service
Protocol: Established rules for official ceremonies and social skills, or in the context of computing, rules governing data communication.
Service: A tool to establish a specific type of communication (e.g., print service).
Sending an SMS Text Message: A Communication Protocol Example
Steps to send an SMS:
- Write your message.
- Enter the recipient’s phone number.
- Send the message.
- Wait for the message delivery confirmation.
- If the message doesn’t arrive within five minutes, retry.
Another example of a communication protocol is HTTP for browsing the web.
Hardware Elements of a Classroom Network
Essential hardware components include:
- Processors
- Memory
- Storage Devices (Hard Drives, Diskettes)
- Input Peripherals (Mouse, Keyboard)
- Output Peripherals (Screen, Printer)
- Special Input/Output Units (Video Card, Sound Card, Modem)
Common Elements of Computer Networks
- Workstations
- Network Interface Cards (NICs)
- Cabling System
- Network Interconnect Devices (Routers, Switches)
Reasons for Using a Computer Network
We can connect multiple computers with a single cable, sharing resources and information.
File Transfer Methods: Advantages and Disadvantages
Two methods for transferring a file between computers:
1. Splitting the file into fragments:
Advantages: Faster transmission as smaller parts are sent, easier error management.
Disadvantages: Requires reassembly and confirmation for each fragment.
2. Sending the entire file:
Advantages: Simpler process, single confirmation.
Disadvantages: Slower for large files, potential for complete retransmission in case of errors, increased risk of virus transmission.
De Facto Standard Software Products
A de facto standard is a product widely accepted in the market due to its extensive use. An example is the IBM PC and its successors, as most manufacturers copied IBM’s designs.
Information Transfer Methods: Advantages and Disadvantages
Comparison of information transfer methods:
| Method | Advantages | Disadvantages |
|---|---|---|
| Circuit Switching | Information always arrives in order. An error doesn’t lose the entire message (but requires retransmission). Better channel congestion control (reserves channel for each connection). | Time lost in establishing the connection. Entire message resends on error. Communication interrupted by link failure. |
| Message Switching | Information always arrives. No time wasted establishing a connection. Communication not interrupted by link failure. | An error loses the entire message. No optimal channel congestion control (no reserved channel). |
| Packet Switching | No time wasted establishing a connection. An error doesn’t lose the entire message (only lost packets are resent). Communication not interrupted by link failure. | Information may arrive out of order. No optimal channel congestion control (no reserved channel). |