How do the Internet and Internet technology work, and how do they support communication and e-business?
· The Internet is a worldwide network of networks that uses the client/server model of computing and the TCP/IP network reference model. Every computer on the Internet is assigned a unique numeric IP address.
· The domain name system (DNS) converts IP addresses to more user-friendly domain names. Worldwide Internet policies are established by organizations and government bodies, such as the Internet Architecture Board (IAB) and the World Wide Web Consortium (W3C).
· Major Internet services include e-mail, newsgroups, chatting, instant messaging, Telnet, file transfer protocol (FTP), and the Web. Web pages are based on Hypertext Markup Language (HTML) and can display text, graphics, video, and audio.
· Web site directories, search engines, and RSS (Really Simple Syndication) technology help users locate the information they need on the Web. RSS, blogs, social networking, and wikis are features of Web 2.0.
· Firms are also starting to realize economies by using Voice-over Internet Protocol (VoIP) technology for voice transmission and by using virtual private networks (VPNs) as low-cost alternatives to private WANs.
2. What are the principal technologies and standards for wireless networking, communication, and Internet access?
· Cellular networks are evolving toward high-speed, high-bandwidth, digital packet-switched transmission. Broadband 3G networks are capable of transmitting data at speeds ranging from 144 kilobits per second (kbps) to more than 2 Mbps.
· 4G networks capable of transmission speeds that could reach 1 gigabits per second (Gbps) are starting to be rolled out.
· Major cellular standards include Code Division Multiple Access (CDMA), which is used primarily in North America, and Global System for Mobile Communications (GSM), which is the standard in much of the rest of the world. Standards for wireless computer networks include Bluetooth (802.15) for small personal area networks (PANs), Wi-Fi (802.11) for local area networks (LANs), and WiMax (802.16) for metropolitan area networks (MANs).
3. What are the main telecommunications transmission media and types of networks?
· The principal physical transmission media are twisted copper telephone wire, coaxial copper cable, fibre-optic cable, and wireless transmission.
· Twisted wire enables companies to use existing wiring for telephone systems for digital communication, although it is relatively slow.
· Fibre-optic and coaxial cable are used for high-volume transmission but are expensive to install. Microwave and communications satellites are used for wireless communication over long distances.
· Local area networks (LANs) connect personal computers (PCs) and other digital devices together within a 500-metre radius and are used today for many corporate computing tasks. Network components may be connected together using a star, bus, or ring topology.
· Wide area networks (WANs) span broad geographical distances, ranging from several miles to continents, and are private networks that are independently managed. Metropolitan area networks (MANs) span a single urban area. Digital subscriber line (DSL) technologies, cable Internet connections, and T1 lines are often used for high-capacity Internet connections.
· Cable Internet connections provide high-speed access to the Web or corporate intranets at speeds of up to 10 megabits per second (Mbps). A T1 line supports a data transmission rate of 1.544 Mbps.
