Thương mại điện tử - Chapter 6: Telecommunications and networks

TelecommunicationsAnd NetworksChapter6Identify several major developments and trends in the industries, technologies and business applications of telecommunications and Internet technologies.Provide examples of the business value of Internet, intranet, and extranet applications.Learning ObjectivesLearning ObjectivesIdentify the basic components, functions, and types of telecommunications networks used in business.Explain the functions of major types of telecommunications network hardware, software, media, and services.Why Study Networking?When computers are networked, two industries – computing and communications – converge, and the result is vastly more than the sum of the parts.Suddenly, computing applications become available for business-to-business coordination and commerce, and for small as well as large organizations.Case #1: Wireless Business ApplicationsBusiness Value of Wireless:Time is money. Pocket PCs help reduce travel time at Celanese Chemicals related to plant equipment diagnosis.Fidelity Investments attracts customers by offering services via wireless devices.GM uses wireless devices to improve forklift operator productivity and cut costs.Case #1: Wireless Business ApplicationsWhat is the business value of wireless technologies in the chemicals and automotive manufacturing industries? What other manufacturing applications might benefit from wireless technologies? Why?What are some of the business benefits of wireless technologies in finance and investments? What other applications would you recommend? Why? Check the website of Fidelity.com to help you answer.Case #1: Wireless Business ApplicationsWhat are some of the business benefits and challenges of using wireless technologies in retailing? What are some other applications that might be beneficial to consumers, as well as retailers? Why?What are some of the major challenges limiting the widespread use of wireless technologies in many business applications? What can be done to meet such challenges?TelecommunicationsDefinition:The exchange of information in any form (voice, data, text, images, audio, video) over networksTrends in TelecommunicationsOpen SystemsDefinition:Information systems that use common standards for hardware, software, applications, and networkingConnectivityDefinition:The ability of networked computers and other devices to easily access and communicate with each other and share informationInteroperabilityDefinition:The ability of an open system to enable the many different applications of end users to be accomplished using the different varieties of computer systems, software packages, and databases provided by a variety of interconnected networksDigital Network TechnologiesDefinition:Digital transmission technologies that transmit information in the form of discrete pulsesBenefits:Higher transmission speedsMovement of larger amounts of informationGreater economyLower error ratesBusiness Value of TelecommunicationsInternetDefinition:A network made up of millions of smaller private networks each with the ability to operate independent of, or in harmony with, all the other millions of networks connected to the InternetInternetInternet ApplicationsBusiness Use of the InternetBusiness Value of the InternetIntranetDefinition:A network inside an organization that uses Internet technologies to provide an Internet-like environment within the enterprise for information sharing, communications, collaboration, and the support of business processesBusiness Value of IntranetsCommunications and Collaboration – includes email, voicemail, paging, faxes, and groupwareWeb Publishing – easy, attractive and low-cost way of publishing and accessing multimedia business informationBusiness Operations and Management – platform for developing and deploying critical business applications to support business operations and managerial decision making across the inter-networked enterpriseBusiness Value of IntranetsExtranetDefinition:Network links that use Internet technologies to interconnect the intranet of a business with the intranets of its customers, suppliers, or other business partnersBusiness Value of ExtranetsIntranets & ExtranetsCase #2: Serving Citizens without WiresMEMA Technologies:Global-positioning satellite communicationsCellular phonesGeospatial technologiesMicroelectronics technologiesCase #2: Serving Citizens without WiresFeatures:A device to communicate warnings to properly position individuals before an event happensA tool to collect timely information after a disaster hitsCase #2: Serving Citizens without WiresWhat is the business value of advanced mobile technologies to Maryland’s emergency management services?In what other government services could GPS serve to provide business value? Give some examples.Are there disadvantages or risks associated with the deployment of GPS systems to monitor the location of people? Explain.Case #2: Serving Citizens without WiresWhat is the business value of the various applications of GPS satellite networks beyond those discussed in the case? Check out the websites of satellite services providers like Hughes Network Systems (www.hns.com) or G-Com International (www.g-com.com) to help you answer.Telecommunications Network ComponentsTerminals – any input/output device that uses telecommunications networks to transmit or receive dataTelecommunications Processors – devices that perform control and support functionsTelecommunications Channels – media over which data are transmitted and receivedComputers – all sizes and typesTelecommunications Control Software – programs that control telecommunications activitiesTelecommunications Network ComponentsTypes of Telecommunications NetworksWide Area Network (WAN) – network that covers a large geographic areaLocal Area Network (LAN) – network connecting information processing devices within a limited physical areaVirtual Private Network (VPN) – secure network that uses the Internet as its main backbone network, but relies on network firewalls, encryption, and other security features of its Internet and intranet connections and those of participating organizationsLAN & VPNTypes of Telecommunications NetworksClient/Server – PCs and workstations, called clients are interconnected by local area networks and share application processing with network serversNetwork Computing – Thin clients provide a browser-based user interface for processing small application programsPeer-to-Peer – file-sharing software connects each PC to a central server or to another online user’s PCClient/ServerClient/Server & Network ComputingPeer-to-PeerPeer-to-PeerTelecommunications MediaTwisted-Pair Wire – copper wire twisted into pairsCoaxial Cable – sturdy copper or aluminum wire wrapped with spacers to insulate and protect itFiber Optics – one or more hair-thin filaments of glass fiber wrapped in a protective jacketTelecommunications MediaWireless TechnologiesTerrestrial Microwave – earthbound microwave systems that transmit high-speed radio signals in a line-of-sight path between relay stations spaced approximately 30 miles apartCommunications Satellites - high-earth orbit communications satellites placed in stationary geosynchronous orbitsWireless TechnologiesCellular and PCS Systems – a geographic area divided into cells with one low-power transmitter device per cell used to relay calls from one cell to anotherWireless LANs –high- or low-frequency radio technology installed in an office or buildingWireless Web – wireless, Web-enabled information appliances accessing the Internet, intranets and extranetsWireless Application Protocol (WAP)Telecommunications ProcessorsModems – convert digital signals from a computer into analog frequencies that can be transmitted over ordinary telephone linesMultiplexers – allows a single communications channel to carry simultaneous data transmissions from many terminalsModemTelecommunications TechnologiesInternetwork ProcessorsSwitch – makes connections between telecommunications circuits in a networkRouter – intelligent communications processor that interconnects networks based on different protocolsHub – a port switching communications processorGateway – connects networks using different communications architecturesCommunications ProcessorsNetwork ProcessorsNetwork ManagementTraffic Management – manage network resources and traffic to avoid congestion and optimize telecommunications service levels to usersSecurity – provide authentication, encryption, firewall, auditing and enforcementNetwork ManagementNetwork Monitoring – troubleshoot and watch over the network, informing network administrators of potential problems before they occurCapacity Planning – survey network resources and traffic patterns and users’ needs to determine how best to accommodate the needs of the network as it grows and changesNetwork TopologiesStar – ties end user computers to a central computerRing – ties local computer processors together in a ring on a relatively equal basisBus – local processors share the same communications channelNetwork TopologiesNetwork TopologiesNetwork Architectures & ProtocolsProtocol – standard set of rules and procedures for the control of communications in a networkNetwork Architecture – the use of standard protocols, standard communications hardware and software interfaces and the design of a standard multilevel interface between end users and computer systems with the goal of promoting an open, simple, flexible, and efficient telecommunications environmentOSI & TCP/IP ModelsOpen Systems Interconnection (OSI) - model is a seven-layer model that serves as a standard model for network architecturesTransmission Control Protocol / Internet Protocol (TCP/IP) – is a five layer telecommunications protocol used by the InternetOSI & TCP/IP ModelsIP AddressBandwidthDefinition:Classification of communications speed and capacity of telecommunications networksTransmission Rates:Narrow-band – low-speedBroadband – high-speed Transmission SpeedsSwitching AlternativesCircuit Switching – a switch opens a circuit to establish a link between a sender and receiver; it remains open until the communication session is completedMessage Switching – a message is transmitted a block at a time from one switching device to anotherSwitching AlternativesPacket Switching – messages are divided into fixed or variable length packets, and packets are sent across networksCell Switching – breaks voice, video and other data into fixed cells of 53 bytes and routes them to their next destination in the networkCase #3: Wi-Fi NetworksBenefits:SuperfastLower costCase #3: Wi-Fi NetworksChallenges:Hit-or-miss hotspotsLost productivity due to disruptionsMust create billing systemsMust establish technical standardsMust develop tighter security measuresCase #3: Wi-Fi NetworksWhat are the business benefits of Wi-Fi networks?What are some of the problems faced by companies who are using Wi-Fi networks? What are some solutions to those problems?What are some other business uses for Wi-Fi networks not mentioned in this case? What are their business benefits and challenges?Case #4: Voice Over IPServices:Combine email with voicemailAudio-conferencingCollaboration technologiesVideoCase #4: Voice Over IPBenefits:Install one line to carry voice and dataReduced staff trainingImproved productivityCase #4: Voice Over IPWhat are the main benefits that can be gained by companies that switch to VoIP systems?What are some of the major cost factors that may limit a positive rate of return from investments in VoIP projects?Should more companies switch to VoIP systems? Visit the websites of Avaya and Cisco Systems to view their VoIP news, products, and services to help you answer.SummaryOrganizations are becoming networked enterprises that use the Internet, intranets, and other telecommunications networks to support business operations and collaboration within the enterprise, and with their customers, suppliers, and other business partners.Telecommunications technology is moving toward open, inter-networked digital networks for voice, data, video and multimedia.SummaryOpen systems with unrestricted connectivity using Internet technologies are the primary telecommunications technology drivers in e-business systems.Companies are deriving strategic business value from the Internet, which enables them to disseminate information globally, communicate and trade interactively with customized information and services for individual customers, and foster collaboration of people and integration of business processes within the enterprise and with business partners.SummaryBusinesses are installing and extending intranets throughout their organizations to:Improve communications and collaboration among individuals and teams within the enterprisePublish and share valuable business information easily, inexpensively, and effectively via enterprise information portalsDevelop and deploy critical applications to support business operations and decision makingSummaryThe primary role of extranets is to link the intranet resources of a company to the intranets of its customers, suppliers, and other business partners.The major generic components of any telecommunications network are:TerminalsTelecommunications processorsCommunications channelsComputersTelecommunications softwareEnd of ChapterChapter6