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Unformatted text preview: Chapter 7. Telecommunica3ons, the Internet, and Wireless Technology Part 1. Networking Basics • Iden3fy the principal components of telecommunica3ons networks and key networking technologies • Describe the main telecommunica3ons transmission media and types of networks • Explain how the Internet and Internet technology work and how they support communica3on and e‐business • Iden3fy the principal technologies and standards for wireless networking, communica3on, and Internet access • Assess the value to business of radio frequency iden3ﬁca3on (RFID) and wireless sensor networks Learning Objec3ves Produced by Dr. Brian Janz 1 What Is A Computer Network? • Two or more connected computers • Major components in simple network – Client computer – Server computer – Network interfaces (NICs) – Connec3on medium – Network opera3ng system – Hub or switch – Router Components of a Simple Computer Network Figure 7-1 Produced by Dr. Brian Janz 2 Types of Networks • Local‐area networks (LANs) – Client/server or peer‐to‐peer – Ethernet – physical network standard – Topologies: star, bus, ring • Campus‐area networks (CANs) • Metropolitan‐area networks (MANs) • Wide‐area networks (WANs) Network Topologies Figure 7-6 Produced by Dr. Brian Janz 3 Networks In Large Companies • Components can include: – Hundreds of local area networks (LANs) linked to ﬁrm‐wide corporate network – Various powerful servers • Web site • Corporate intranet, extranet • Backend systems – Mobile wireless LANs (Wi‐Fi networks) – Videoconferencing system – Telephone network – Wireless cell phones Corporate Network Infrastructure Figure 7-2 Produced by Dr. Brian Janz 4 Communica3ons Networks • Physical transmission media – Twisted telephone pairs – Coaxial cable – Fiber op3cs and op3cal networks • Wireless transmission media and devices – Microwave – Satellites – Cellular telephones • Transmission speed/capacity – Hertz – Bandwidth Signals: Digital vs. Analog • Modem: Translates (or “MODulates”) digital signals into analog form, and then retranslates (or “DEModulates”) back to digital Figure 7-5 Produced by Dr. Brian Janz 5 Packet Switching • Method of slicing digital messages into parcels (packets), sending packets along diﬀerent communica3on paths as they become available, and then reassembling packets at des3na3on • Previous circuit‐switched networks required assembly of complete point‐to‐point circuit • Packet switching more eﬃcient use of network’s communica3ons capacity Packet‐Switched Networks and Packet Communica3ons Figure 7-3 Produced by Dr. Brian Janz 6 TCP/IP and Connec3vity • Connec3vity between computers is enabled by protocols – Protocols: Rules that govern transmission of informa3on between two points • Transmission Control Protocol/Internet Protocol (TCP/IP) – Common worldwide standard that is basis for Internet • 4‐layer DoD reference model for TCP/IP – Applica3on layer – Transport layer – Internet layer – Network interface layer The Transmission Control Protocol/Internet Protocol (TCP/IP) Reference Model Figure 7-4 Produced by Dr. Brian Janz 7 Chapter 7. Telecommunica3ons, the Internet, and Wireless Technology Part 2. The Global Internet The Global Internet • What is the Internet? • Connec3ng to the Internet – Internet service providers (ISPs) • DSL, cable, satellite, T lines (T1, T3) • Internet addressing and architecture – IP addresses – The domain name system • Hierarchical structure • Top‐level domains Produced by Dr. Brian Janz 8 The Domain Name System Figure 7-8 The Global Internet • Internet Architecture – Trunk lines (backbone networks) – Regional networks – ISPs • Internet Governance – No formal management – Policies established by professional, government organiza3ons, e.g., IAB, ICANN, W3C • The Future Internet – IPv6 – Internet2, NGI Produced by Dr. Brian Janz 9 Internet Network Architecture Figure 7-9 Internet Services • E‐mail • Chaeng and instant messaging • Newsgroups • Telnet • File Transfer Protocol (FTP) • World Wide Web • Voice over IP (VoIP) • Virtual private networks (VPNs) Produced by Dr. Brian Janz 10 Client/Server Compu3ng on the Internet Figure 7-10 How Voice Over IP (VoIP) Works Figure 7-11 Produced by Dr. Brian Janz 11 A Virtual Private Network (VPN) Over the Internet Figure 7-12 The World Wide Web • HTML (Hypertext Markup Language): – Formats documents for display on Web • Hypertext Transfer Protocol (HTTP): – Communica3ons standard for transferring web pages • Uniform resource locators (URLs): – Addresses of web pages • e.g., hgp://www.memphis.edu • Web servers • Sohware for loca3ng and managing web pages Produced by Dr. Brian Janz 12 The Global Internet: Web 2.0 • Second‐genera3on Internet‐based services enabling people to collaborate, share informa3on, and create new services online • Cloud compu3ng, mashups and widgets • Blogs: Chronological, informal websites created by individuals using easy‐to‐use weblog publishing tools • RSS (Really Simple Syndica3on): Syndicates Web content so aggregator sohware can pull content for use in another seeng or viewing later • Wikis: Collabora3ve websites where visitors can add, delete, or modify content on the site The Global Internet: Web 3.0 • Eﬀorts to make using Web more produc3ve – Ineﬃciency of current search engines • Seman3c Web – Collabora3ve eﬀort to add a layer of meaning on top of Web, to reduce the amount of human involvement in searching for and processing Web informa3on • Other, more modest views of the future Web – Increase in cloud compu3ng, SaaS – Ubiquitous connec3vity between mobile and other access devices – Make Web a more seamless experience Produced by Dr. Brian Janz 13 Intranets and Extranets • Intranets – Use exis3ng network infrastructure with Internet standards/ sohware developed for the Web – Create networked applica3ons that can run on many types of computers – Protected by ﬁrewalls • Extranets – Allow authorized vendors and customers access to an internal intranet – Used for collabora3on – Firewall protec3on cri3cal Chapter 7. Telecommunica3ons, the Internet, and Wireless Technology Part 3. Wireless Telecommunica3ons Produced by Dr. Brian Janz 14 The Wireless Revolu3on • Wireless devices – PDAs, BlackBerry, smart phones • Cellular systems – Compe3ng standards for cellular service • United States: CDMA • Most of rest of world: GSM – Third‐genera3on (3G) networks • Higher transmission speeds suitable for broadband Internet access Wireless Computer Networks and Internet Access Bluetooth (IEEE 802.15) – Links up to 8 devices in 10‐m area using low‐ power, radio‐based communica3on – Useful for personal networking (PANs) Produced by Dr. Brian Janz 15 Wi‐Fi (IEEE 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/ transmiger for connec3ng wireless devices to a wired LAN • Hotspots: One or more access points in public place to provide maximum wireless coverage for a speciﬁc area • Weak security features WiMAX (IEEE 802.16) • Wireless access range of 31 miles • Require WiMAX antennas • Sprint Nextel building WiMAX networks Produced by Dr. Brian Janz 16 Wireless Sensor Networks • Networks of hundreds or thousands of interconnected wireless devices embedded into physical environment to provide measurements of many points over large spaces • Used to monitor building security, detect hazardous substances in air, monitor environmental changes, traﬃc, or military ac3vity • Devices have built‐in processing, storage, and radio frequency sensors and antennas • Require low‐power, long‐las3ng bageries and ability to endure in the ﬁeld without maintenance Radio Frequency Iden3ﬁca3on (RFID) • Small tags with antenna and embedded microchips containing data about an item as well as loca3on • Tags transmit radio signals over short distances to special RFID readers, which send data over network to computer for processing – Ac3ve RFID: Tags have bageries, data can be rewrigen, range is hundreds of feet, more expensive – Passive RFID: Range is shorter, also smaller, less expensive, powered by radio frequency energy • Common uses: – Automated toll‐collec3on – Tracking goods in a supply chain • Reduced cost of tags making RFID viable for many ﬁrms Produced by Dr. Brian Janz 17 How RFID Works Figure 7-17 Produced by Dr. Brian Janz 18 ...
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This note was uploaded on 02/24/2011 for the course MIS 7650 taught by Professor Janz during the Spring '11 term at U. Memphis.
- Spring '11