Internet Connections and Technologies: A Comprehensive Overview

1. Chapter 7 (Part 2) Telecommunications, the Internet,and Wireless Technology

2. What is internet? • The Internet is the global system of interconnected computer networks that use the Internet protocol suite (TCP/IP) to link billions of devices worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks of local to global scope, linked by a broad array of wireless, and wired networking technologies. • Internet connections (wired broadband and wireless broadband) are provided by Internet Service Provider (ISP).

3. Technologies for wired broadband -Digital Subscriber Line (DSL): Need to have a landline phone -Asymmetric DSL (ADSL): Most popular form of DSL. Available in Bangladesh. Example: BTCL -Fiber to the Home (FTTH): Use internet from optical fiber. Available in Bangladesh. Example: Link3 -Cable internet connections: Provided by cable TV providers -T lines: Dedicated lines for businesses and governments that require high-speed guaranteed service levels. Not available to end users. • Connection medium: • DSL: Telephone wire • FTTH: Optical fiber • Cable internet connection: Coaxial cable • T lines: Telephone wire • Speed ranges: • DSL: 385 kbps to 40 mbps, FTTH: up to 150 mbps • Cable internet connections: Most providers provide 1 mbps to 6 mbps • T lines: T1- 1.54 mbps, T3- 45 mbps

4. Internet address • The internet is based on the TCP/IP networking protocol to send data from one computer to other computers • Each computer on the internet is assigned with a unique address called Internet Protocol Address (IP Address). • IP address is represented by four strings of numbers ranging form 0 to 255 separated by periods (dots) • Example: 207.43.123.241

5. Major Internet services (Table 7.3 ) • E-mail • Chatting and instant messaging • Newsgroups • Telnet • File Transfer Protocol (FTP) • World Wide Web

6. The World Wide Web • Website: A collection of web pages • HTML (Hypertext Markup Language): • Formats documents for display on Web by using HTML tags • Example: <Name> Kabid Md Surid </Name> <address> Somewhere in Dhaka </address> • Hypertext Transfer Protocol (HTTP): • Communications standard used for transferring Web pages from web server to the client computers. E.g. http://www.megacorp.com • Uniform resource locators (URLs): • Addresses of Web pages • E.g. http://www.megacorp.com/content/features/082602.html • Web servers • Used for locating and managing Web pages

7. Searching information on internet • Search engines • Started in early 1990s as relatively simple software programs using keyword indexes • Search engine marketing • Today, major source of Internet advertising revenue happens via search engine marketing, using complex algorithms and page ranking techniques to locate results • Shopping bots • Use intelligent agent software for searching Internet for shopping information. Example: pricegrabber.com

8. Web 2.0 • Web 2.0 • Four defining features • Interactivity: Search customized information as per user criteria • Real-time user control: Update, delete, Copy, paste of information; build applications on web using cloud computing • Social participation • User-generated content: You Tube videos • Technologies and services behind these features • Cloud computing • Blogs/RSS (Rich Site Summary) • Mashups: enables mix and match web contents to create useful information • Wikis: Example- Wikipedia • Social networks: Build communities and friends

9. Cellular systems • Competing standards for cellular service • CDMA: Citycell • GSM: Grameenphone, Robi • Third-generation (3G) networks • Speed range is 144 Kbps – 2Mbps • 4G networks • Speed range is 100 Mbps – 1Gbps

10. The Wireless Computer Networks and Internet • Bluetooth (802.15) • Links up to 8 devices in 10-m area • Useful for personal area networking (PANs) and in business to transmit data from handheld devices to other transmitters • Wi-Fi (802.11) • Set of standards: 802.11a, 802.11b, 802.11g, 802.11n • Used for wireless LAN and wireless Internet access • Use access points: Device with radio receiver/transmitter for connecting wireless devices to a wired LAN

11. The Wireless Computer Networks and Internet • Wireless computer networks and Internet access • Wi-Fi (cont.) • Hotspots: Access points in public place to provide maximum wireless coverage for a specific area • Weak security features • WiMax (802.16) • Wireless access range of 31 miles • Require WiMax antennas • Fix the problems of not having Wi-Fi and Fixed broadband connectivity

12. The Wireless Computer Network A BLUETOOTH NETWORK (PAN) Bluetooth enables a variety of devices, including cell phones, PDAs, wireless keyboards and mice, PCs, and printers, to interact wirelessly with each other within a small 30-foot (10-meter) area. In addition to the links shown, Bluetooth can be used to network similar devices to send data from one PC to another, for example. FIGURE 7-15

13. The Wireless Internet Access AN 802.11 WIRELESS LAN Mobile laptop computers equipped with network interface cards link to the wired LAN by communicating with the access point. The access point uses radio waves to transmit network signals from the wired network to the client adapters, which convert them into data that the mobile device can understand. The client adapter then transmits the data from the mobile device back to the access point, which forwards the data to the wired network. FIGURE 7-16