This document discusses telecommunications, the internet, wireless technology, and their components. It covers analog and digital signals, wired and wireless transmission methods, network topologies like star, bus, and ring networks. It also discusses local and wide area networks, standards like TCP/IP and OSI models, internet service providers, the world wide web, electronic business technologies, firewalls, extranets, web content management systems, and challenges of new IT infrastructures.
2. Components and functions of a Telecommunications System
• Transmit information
• Establish interface between sender and
the receiver
• Route messages along most efficient
paths
• Perform elementary processing of
information
• Perform editorial tasks on data
• Convert message speed or format
• Control flow of information
3. Analog Signal
• Continuous waveform
• Passes through communications
medium
• Used for video, audio and voice
communications
Digital signal
• Discrete waveform
• Transmits data coded into two discrete
states as 1-bits and 0-bits
• Used for data communications
4. Communication channels
Wired transmission
• Twisted wire: Telephone systems
• Coaxial cable: Cable television
• Fiber optics and optical networks: Dense wave division multiplexing
(DWDM)
Wireless transmission:
• Microwave, Satellites, Paging systems, Cellular telephones,
Personal communication Services, Personal digital assistants,
Mobile data networks
Proprieties
Transmission speed: Baud, bandwidth
5. Star network : All computers and others devices are connected to a central
host computer
Bus Network: Links a number of computers by a single circuit
Ring Network: All computers are linked by a closed loop
Communication Networks
Topologies
6. Local Area Networks
• Require their own dedicated channels
• Encompass a limited distance
• Gateway, router, Network Operating System
(NOS), peer-to-peer
Wireless LANs-WLAN
• Wi-Fi (IEEE 802.11b) standard: Up to 11 Mbps,
low cost, high-speed mobile Internet access,
links work groups
• Bluetooth standard: Up to 720 Kbps, small
personal area networks
• Span large geographical distance
• Consist of variety of cable, satellite, and microwave
technologies
• Switched lines, dedicated lines
Local Area Networks (LANs) and Wide Area Networks (WANs)
7. Electronic Commerce Electronic Business Technologies.
• E-mail: eliminates telephone tag and costly long distance telephone charges
• Groupware: Enables work groups at different locations to participate in discussion
forums and work on shared documents and projects
• Teleconferencing: ability to confer with a group of people simultaneously
• Data conferencing: Two or more users can edit and modify data files simultaneously
• Videoconferencing: Participants are able to see each other over video screens
• E-learning: Instruction delivered online using the Internet or private networks
8. THE NEW INFORMATION TECHNOLOGY (IT) INFRASTRUCTURE
Standards and Connectivity for Digital Integration
• Open systems Interconnect OSI : determines a
multiple-layer layout to interconnect different equipment.
• TCP/IP model: it is based on OSI layers but it’s focused on
the transmission. It’s a short practical model, not so
theoretical than OSI.
9. What Is Internet?
Internet Service Provider (ISP)
• Commercial organization with a permanent
connection to Internet
• Sells temporary connections to subscribers
"The World Wide Web (WWW, or simply Web) is an
information space in Which the items of interest,
Referred to as resources, are Identified by the global
identifiers called Uniform Resource Identifiers (URI).“
Main Features
• Based on a standard hypertext language called
Hypertext markup language (HTML)
• Combines text, hypermedia, graphics, and sound
• Handles all types of digital communication
• You use graphical user interfaces for easy viewing
Firewall :Hardware or software Placed Between an
organization's internal network and external network and
Prevents outsiders from invading private networks
Extranets: Private intranets extended to Authorized users
outside company
10. Web Content Management Tool
A content management system (CMS) is a system
providing a collection of Procedures used to
manage work flow in a collaborative environment.
These Procedures can be manually or computer-based.
The Procedures are designed to do the Following:
• Allow for a large number of people to Contribute to and
share stored data
• Control access to data, based on user roles (defining
Which information users or user groups can view, etc.).
• Aid in easy storage and retrieval of data
• Reduce repetitive duplicate input
• Improve the ease of report writing
• Improve Communication between users
The Challenge of the New Information
Technology Infrastructure
• Loss of management control
• Connectivity and application integration challenges
• Organizational change requirements
• Hidden costs of enterprise computing
• Scalability, reliability, and security downtime