This document discusses the components of telecommunications systems including different types of signals, methods of conversion between analog and digital signals, communication channels, network processors and topologies, local and wide area networks, broadband technologies, and electronic commerce services. Analog signals are continuous waveforms that pass through media for video, audio and voice, while digital signals use discrete values of 1s and 0s for data transmission. Communication occurs through wired or wireless channels and is processed by front-end processors, concentrators, controllers and multiplexers within star, bus or ring network topologies. Local and wide area networks provide connectivity along with value-added networks and other services to enable electronic mail, conferencing, commerce and distance learning.

1. Telecommunications System
Components

2. Types of signals: Analog and Digital
• Analog:
– Continious waveforms
– Passes through communications medium
– Used for video, audi and voice communications
• Digital:
Discrete waveforms
Transmits data coded into two discrete states as 1-bits or 0-bits
Used för data communications

3. Methods of conversation
• Analog to digital

4. Functions of a modem
• Translates computers digital signal into analog
and vice versa

5. Communications Channels
• Wired transmission
• Wireless transmission

6. Communications Processers and
Software
• Front-end processor
• Concentrator
• Controller
• Multiplexer

7. Network topologies
• Star network
• Bus network
• Ring network

8. Local Area Networks (LAN´s) &
Wide Area Networks (WAN´s)

9. Network services and Broadband
Technologies
• Value-added networks (VAN´s)
• Other network services

10. Electronic Commerce & Electronic
Business Technologies
• Electronic mail and groupware = E-mails and
Groupware
• Voice mail and fax
• Teleconferencing
• Dataconferencing
• Videoconferencing
• Digital information services, distance learning and
E-learing
• EDI = Electronic data Interchange
•