Telecommunications and networks, the Internet

INFO 1500 Introduction to IT FundamentalsLearning Objectives6. Telecommunications andnetworks, the Internet1. What are the principal components of telecommunicationsnetworks and key networking technologies?2. What are the main telecommunications transmission mediaand types of networks?3. How does the Internet and Internet technology work andhow do they support communication and e‐business?Alexander Nikov4. What are the principal technologies and standards forwireless networking, communication, and Internet access?5. Why are radio frequency identification (RFID) and wirelesssensor networks valuable for business?6-2Hyundai Heavy Industries Creates AWireless ShipyardHyundai Heavy Industries Creates AWireless Shipyard• Problem: Shipbuilding space is too large (4.2 sq mi)and complex to track inventory in real‐time, limitingefficiency• Solution: High‐speed wireless network built by KTCorp, using radio sensors, notebooks, mobiles, Webcams• Illustrates:–Powerful capabilities and solutions offered bycontemporary networking technology–Use of radio sensor technologies to track inventory6-3 6-4

OutlineNetworking and communication Trends• Convergence:1. Telecommunications and Networking in Today’sBusiness World2. Communications Networks3. The Global Internet4. Wireless Networks– Telephone networks and computer networksconverging into single digital network using Internetstandards–E.g. cable companies providing voice service• Broadband:–More than 60% U.S. Internet users have broadbandaccess• Broadband wireless:6-5–Voice and data communication as well as Internetaccess are increasingly taking place over broadbandwireless platforms6-6What is a computer network?Components of a Simple Computer Network•Two or more connected computers•Major components in simple network– Client computer– Server computer– Network interfaces (NICs)– Connection medium– Network operating system– Hub or switch•Routers– Device used to route packets of data through differentnetworks, ensuring that data sent gets to the correct address6-7FIGURE 7-1Illustrated here is a very simple computer network, consisting of computers, anetwork operating system residing on a dedicated server computer, cable(wiring) connecting the devices, network interface cards (NICs), switches, anda router.6-8

Components of networks in large companies• Hundreds of local area networks (LANs) linked tofirmwide corporate network•Various powerful servers– Web site– Corporate intranet, extranet– Backend systems• Mobile wireless LANs (Wi‐Fi networks)• Videoconferencing systemToday’s corporatenetworkinfrastructure is acollection of manydifferent networksfrom the publicswitched telephonenetwork, to theInternet, tocorporate local areanetworks linkingworkgroups,departments, oroffice floors.Corporate Network Infrastructure• Telephone network•Wireless cell phones6-9FIGURE 7-26-10Key networking technologiesKey networking technologies (cont.)• Client/server computing– Distributed computing model– Clients linked through network controlled by networkserver computer–Server sets rules of communication for network andprovides every client with an address so others canfind it on the network–Has largely replaced centralized mainframecomputing–The Internet: Largest implementation of client/servercomputing•Packet switching–Method of slicing digital messages into parcels(packets), sending packets along differentcommunication paths as they become available, andthen reassembling packets at destination–Previous circuit‐switched networks required assemblyof complete point‐to‐point circuit–Packet switching more efficient use of network’scommunications capacity6-116-12

Packed‐switched Networks And PacketCommunicationsKey networking technologies (cont.)• TCP/IP and connectivity– Connectivity between computers enabled by protocols– Protocols: Rules that govern transmission of informationbetween two points– Transmission Control Protocol/Internet Protocol (TCP/IP)• Common worldwide standard that is basis for Internet– Department of Defense reference model for TCP/IP•Four layers1. Application layer2. Transport layer3. Internet layer4. Network interface layerFIGURE 7-3Data are grouped into small packets, which are transmitted independently overvarious communications channels and reassembled at their final destination.6-136-14The Transmission Control Protocol/ InternetProtocol (TCP/IP) Reference ModelOutlineThis figure illustrates the fourlayers of the TCP/IPreference model forcommunications1. Telecommunications and Networking in Today’s BusinessWorld2. Communications Networks3. The Global Internet4. Wireless NetworksFIGURE 7-46-156-16

Signals and Types of networksTypes of Networks• Signals: digital vs. analog–Modem: Translates digital signals into analog form• Types of networks–Local‐area networks (LANs)• Campus‐area networks (CANs)• Peer‐to‐peer• Topologies: star, bus, ring– Metropolitan and wide‐area networks•Wide‐area networks (WANs)• Metropolitan‐area networks (MANs)6-1718 6-18Functions Of The ModemNETWORK TOPOLOGIESThe three basicnetwork topologiesare the star, bus, andring.FIGURE 7-5A modem is a device that translates digital signals into analog form (andvice versa) so that computers can transmit data over analog networks suchas telephone and cable networks.6-19FIGURE 7-66-20

Physical transmission mediaBP’s Satellite Transmission System•Twisted wire (modems)• Coaxial cable• Fiber optics and optical networks–Dense wavelength division multiplexing (DWDM)•Wireless transmission media and devices–Microwave– Satellites– Cellular telephones• Transmission speed (hertz, bandwidth)FIGURE 7-7Communication satellites help BP transfer seismic data between oil explorationships and research centers in the United States.6-216-22OutlineThe Global Internet1. Telecommunications and Networking in Today’s BusinessWorld2. Communications Networks3. The Global Internet4. Wireless Networks•What is the Internet?• Internet Addressing and Architecture–The Domain Name System• Hierarchical structure•Top‐level domains– Internet Architecture and Governance•No formal management: IAB, ICANN, W3C–The Future Internet: IPv6 and Internet26-236-24

The Domain Name System• How the internet works• http://www.youtube.com/watch?v=Jj6EHgSsx_U&feature=relatedDomain NameSystem is ahierarchicalsystem with a rootdomain, top-leveldomains, secondleveldomains, andhost computers atthe third level.• How the Internet Works in 5 Minuteshttp://www.youtube.com/watch?v=7_LPdttKXPc&feature=relatedFIGURE 7-8256-26Internet Network ArchitectureInternet servicesThe Internetbackbone connectsto regional networks,which in turn provideaccess to Internetservice providers,large firms, andgovernmentinstitutions. Networkaccess points(NAPs) andmetropolitan areaexchanges (MAEs)are hubs where thebackbone intersectsregional and localnetworks and wherebackbone ownersconnect with oneanother.FIGURE 7-96-27•E‐mail• Chatting and instant messaging• Newsgroups• Telnet• File Transfer Protocol (FTP)•World Wide Web•VoIP•Virtual private network (VPN)6-28

Major Internet ServicesClient/Server Computing On The InternetFIGURE 7-10Client computers running Web browser and other software can access anarray of services on servers over the Internet. These services may all run ona single server or on multiple specialized servers.296-30How Voice Over IP WorksA Virtual Private Network Using The InternetFIGURE 7-11An VoIP phone call digitizes and breaks up a voice message into datapackets that may travel along different routes before being reassembled atthe final destination. A processor nearest the call’s destination, called agateway, arranges the packets in the proper order and directs them to thetelephone number of the receiver or the IP address of the receivingcomputer.This VPN is a privatenetwork of computerslinked using a secure“tunnel” connectionover the Internet. Itprotects datatransmitted over thepublic Internet byencoding the data and“wrapping” them withinthe Internet Protocol(IP). By adding awrapper around anetwork message tohide its content,organizations cancreate a privateconnection that travelsthrough the publicInternet.FIGURE 7-126-316-32

The World Wide WebThe World Wide Web (cont.)•HTML (Hypertext Markup Language):–Formats documents for display on Web• Hypertext Transfer Protocol (HTTP):– Communications standard used for transferring Webpages•Uniform resource locators (URLs):– Addresses of Web pages•E.g.http://www.megacorp.com/content/features/082602.html•Web servers–Software for locating and managing Web pages•Search engines–Started in early 1990s as relatively simple softwareprograms using keyword indexes–Today, major source of Internet advertising revenuevia search engine marketing, using complexalgorithms and page ranking techniques to locateresults• Shopping bots–Use intelligent agent software for searching Internetfor shopping information6-336-34How Google WorksTop U.S. Web Search EnginesThe Google searchengine iscontinuouslycrawling the Web,indexing the contentof each page,calculating itspopularity, andstoring the pages sothat it can respondquickly to userrequests to see apage. The entireprocess takes aboutone-half second.FIGURE 7-136-35FIGURE 7-14Google is the most popular search engine on the Web, handling 72 percentof all Web searches.6-36

Browser Statisticshttp://www.w3schools.com/browsers/browsers_stats.aspWeb 2.0•Four defining features1. Interactivity2. Real‐time user control3. Social participation4. User‐generated content• Technologies and services behind these features– Cloud computing– Blogs/RSS– Mashups & widgets– Wikis– Social networks37 6-376-38Web 3.0 and Other visionsOutline•Web 3.0 − the Semanc Web– Effort of W3C to add meaning to existing Web–Make searching more relevant to user• Other visions–More“intelligent” computing–3D Web– Pervasive Web–Increase in cloud computing, SaaS– Ubiquitous connectivity between mobile and other accessdevices–Make Web a more seamless experience1. Telecommunications and Networking in Today’s BusinessWorld2. Communications Networks3. The Global Internet4. Wireless Networks6-396-40

Cellular systems• Competing standards for cellular service–CDMA: United States–GSM: Rest of world, plus AT&T and T‐Mobile•Third‐generation (3G) networks– Suitable for broadband Internet access– 144 Kbps – 2Mbps•4G networks–Entirely packet‐switched– 100 Mbps – 1GbpsWireless computer networks and Internetaccess• Bluetooth (802.15)–Links up to 8 devices in 10‐m area–Useful for personal networking (PANs) and in businessto transmit data from handheld devices to othertransmitters•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 radioreceiver/transmitter for connecting wireless devices toa wired LAN6-416-42A Bluetooth Network (PAN)An 802.11 Wireless LANBluetooth enables avariety of devices,including cellphones, PDAs,wireless keyboardsand mice, PCs, andprinters, to interactwirelessly with eachother within a small30-foot (10-meter)area. In addition tothe links shown,Bluetooth can beused to networksimilar devices tosend data from onePC to another, forexample.FIGURE 7-156-43Mobile laptopcomputers equippedwith network interfacecards link to the wiredLAN bycommunicating withthe access point. Theaccess point usesradio waves totransmit networksignals from the wirednetwork to the clientadapters, whichconvert them into datathat the mobile devicecan understand. Theclient adapter thentransmits the datafrom the mobiledevice back to theaccess point, whichforwards the data tothe wired network.FIGURE 7-166-44

Wireless computer networks and Internetaccess•Wi‐Fi (cont.)– Hotspots: Access points in public place to providemaximum wireless coverage for a specific area–Weak security features• WiMax (802.16)– Wireless access range of 31 miles– Require WiMax antennas–Sprint Nextel building WiMax network as foundationfor 4G networksRadio frequency identification (RFID)• Use tiny tags with embedded microchips containingdata about an item and location, and antenna•Tags transmit radio signals over short distances tospecial RFID readers, which send data over networkto computer for processing•Active RFID: Tags have batteries, data can berewritten, range is hundreds of feet, more expensive• Passive RFID: Range is shorter, also smaller, lessexpensive, powered by radio frequency energy6-456-46Radio frequency identification (RFID) (cont.)How RFID Works• Common uses:– Automated toll‐collection–Tracking goods in a supply chain• Requires companies to have special hardware andsoftware• Reduction in cost of tags making RFID viable formany firmsFIGURE 7-17RFID uses low-powered radio transmitters to read data stored in a tag atdistances ranging from 1 inch to 100 feet. The reader captures the data fromthe tag and sends them over a network to a host computer for processing.6-476-48

Wireless sensor networks (WSNs)A Wireless Sensor Network• Networks of hundreds or thousands ofinterconnected wireless devices embedded intophysical environment to provide measurements ofmany points over large spaces– Devices have built‐in processing, storage, and radiofrequency sensors and antennas– Require low‐power, long‐lasting batteries and abilityto endure in the field without maintenance• Used to monitor building security, detect hazardoussubstances in air, monitor environmental changes,traffic, or military activityThe small circlesrepresent lowerlevelnodes andthe larger circlesrepresent highendnodes.Lower levelnodes forwarddata to eachother or tohigher-levelnodes, whichtransmit datamore rapidly andspeed upnetworkperformance.FIGURE 7-186-496-50Video case: Unified Communications Systems With VirtualCollaboration: IBM and ForterraVideo case: Unified Communications SystemsWith Virtual Collaboration: IBM and Forterra1. What are the gains in productivity that can result through aunified communications system?2. How does this system support collaboration?3. How realistic is the collaborative design meeting?4. What different kinds of communications tools does thissystem integrate?5. What does virtual reality add to the unified communicationsystem?http://www.youtube.com/watch?v=dhndnl__HkA6-516-52

Video Case: Unified Communications Systems With Virtual Collaboration: IBM and Forterra1. What are the gains in productivity that can resultthrough a unified communications system?Video Case: Unified Communications Systems With Virtual Collaboration: IBM and Forterra2. How does this system support collaboration?Easier to find people, arrange meetings, communicate ondifferent platforms simultaneously. Easier to collaborate, andfaster to reach decisions.Strengthens sense of presence, stronger relationships,memorable experiences, faster problem solving and decisionmaking. Overcomes geographical and time limitations oftraditional meetings.6-536-54Video Case: Unified Communications Systems With Virtual Collaboration: IBM and Forterra3. How realistic is the collaborative designmeeting?Video Case: Unified Communications Systems With Virtual Collaboration: IBM and Forterra4. What different kinds of communications toolsdoes this system integrate?On balance, an interesting believable dialog among designers,marketers and vendors. It would seem to depend on peoplebeing at the computers to work. For instance, if some peoplewere on their cell phones, this system might not work so wellexcept for voice.• Phones,• desktops,• email,• mobile phones,• audio and• Web conferencing.6-556-56

Video Case: Unified Communications Systems With Virtual Collaboration: IBM and Forterra5. What does virtual reality add to the unifiedcommunication system?Virtual reality is not as “real” as telepresence which involveshuman beings appearing on screens. However, if humanscannot be present in the meeting room, they might be able toparticipate in conferences as avatars. Although there is a tradeoff(less realism), it may be more practical..6-57