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Managing Telecommunications

Managing Telecommunications. Telecom & IS Organization . IS departments have been responsible for designing, building, and maintaining the information Just as governments are responsible for building and maintaining streets, roads, and freeways

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Managing Telecommunications

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  1. Managing Telecommunications

  2. Telecom & IS Organization • IS departments have been responsible for designing, building, and maintaining the information • Just as governments are responsible for building and maintaining streets, roads, and freeways • Telecom provides infrastructure for moving information and messages • Internet opened up a new view of telecom of providing a cyberspace

  3. Telecom History • Circuit-switching network • PSTN (POTS) • Suitable for analog voice signals • Overhead of establishing a temporary circuit (seconds) tolerable • Packet-switching network • Aimed at transmitting data • Messages are sent in packets • Assume the intelligent user devices

  4. The Evolving Telecommunications Scene • The Internet can handle all kinds of intelligent user devices • PDAs, VoIP phones, gaming consoles, wireless devices, PCs... • The Internet allows these device to handle different kinds of services • Voice, e-mails, graphics, gaming... • The global telecom infrastructure is changing from a focus on voice to a focus on data

  5. Transformation of Telecom Industry (1) • The telecom structure of old was originally provided by (often Government owned) monopolies (e.g. AT&T) • Gradually, the telecom industry has been deregulated • Telecom industry is even more competitive than computer industry • Bandwidth on fiber is now doubling capacity every four months

  6. Transformation of Telecom Industry (2) • The last mile problem for RBOCs in 1990s • A Fire-hose-to-straw gap • tbps (1012) in backbones VS. 56k or 1.2m in the last mile (Figure 6-1) • RBOCs then became ILECs, and there came new competitors CLECs (competitive LECS) • ILECs bundled local phone access with Internet access • CLECs came up with new connection options • Cable modems, optical fiber, wireless, satellite…

  7. Telecom Technologies and Their Speeds

  8. Case Example: ICG Communications • This CLEC provides voice and data services in 25 metropolitan areas in the United States • It was formed in 1984 to provide local telephone service in Denver. • It expanded to provide long distance, buying up companies with fiber routes • It later focused on being an Internet backbone provider, serving ISPs • When the dot-com bubble burst, ICG filed for bankruptcy, but moved out of bankruptcy in late 2002 • Acquired by Level 3 Communication in 2006

  9. The Internet is the Network of Choice (1) • Internet and telecom surprised us by its fast rise and fall in the past one decade • History of the Internet • In 1960s, APARNET developed by DOD for transferring scientific files • Mainly used for email • Until 1993, still an all-text world-wide network for scientists and academics • Email, FTP, Telnet, Gopher…

  10. The Internet is the Network of Choice (2) • In 1994, Tim Berners Lee invented World Wide Web • URL • HTML • Browser • The Internet has done for telecom what the IBM PC did for computing: brought it "to the masses" • Open architecture of Internet • Interconnectivity

  11. The Internet is the Network of Choice (3) • 3 important attributes of the Internet • Ubiquity • Global reach • Reliability • Alternate routing, scale-free network • Scalability • Easy extension of its reach, increasing performance of websites

  12. The Internet is the Network of Choice (4) Public Website • Intranet • Internet technology used inside an enterprise • Extranet • Internet technology used to connect trading partners, customers, suppliers etc. E Extranet Intranet

  13. Digital Convergence • Intertwining of various forms of media – voice, data and video • All forms of media can be digitized, put into packets and sent over an IP network • Media managed and manipulated digitally and integrated in highly imaginative ways

  14. IP Telephony (1) • The use of Internet to transmit voice to replace their telephone system • A phone with an IP address, voice delivered in digital packets • Previously conceived application of IP telephony • To another IP phone on the LAN • Through the company's WAN to a distant IP phone on another of the company's LANs • Through an IP voice gateway to the PSTN to a standard telephone

  15. IP Telephony (2)

  16. IP Telephony (3)

  17. IP Telephony (4)

  18. Video Telephony • Similar story to IP Telephony • Not video conferencing via a PBX, but rather video over IP • With the appropriate IP infrastructure, video telephony can be, say, launched from an instant-messaging conversation • IP phones with cameras also facilitate it, phone to phone

  19. IPTV • IPTV is television content that, instead of being delivered through traditional broadcast and cable formats, is received by the viewer through IP networks. • Standards used: MPEG2, MPEG4/H.264, MPEG2-TS IP, UDP, RTP, TCP, etc. Voice IP Converged services over copper or fiber Video Data Content Provider Service Provider Delivery Network Home Network

  20. OSI Reference Model • Closed VS. open network • Closed network: using proprietary networking technology • Open network: based on national or international standards • What is a reference model? • A division of functionality together with data flow between the pieces • No detailed standards specified for each layer

  21. An Analogy: Mailing a Letter • Information encapsulated • Envelop vs. packet • Control information on the envelop • Address, services • Each layer wraps the message with its own layer of control information • Headers • Reversed unwrap at the receiving end

  22. Seven Layers Important protocols Application Layer 7 Presentation Layer 6 Session Layer 5 Transport Layer 4 Network Layer 3 Data Link Layer 2 Physical Layer 1

  23. The Physical Layer • Responsibility: • Transmission of raw bits over a communication channel. • Issues: • Mechanical and electrical interfaces • Time per bit • Distances

  24. The Data Link Layer • Responsibility: • Data Link Control sub-layer: provide an error-free communication link • MAC sub-layer: provides DLC with “virtual wires” on multiaccess networks. • Issues: • framing (dividing data into chunks) • header & trailer bits • addressing 10110110101 01100010011 10110000001

  25. The Network Layer • Responsibilities: • Path selection between end-systems (routing). • Subnet flow control. • Fragmentation & reassembly • Translation between different network types. • Issues: • Packet headers • Virtual circuits

  26. The Transport Layer • Responsibilities: • Provides virtual end-to-end links between peer processes. • End-to-end flow control • Issues: • Headers • Error detection • Reliable communication

  27. The Session Layer • Establishes, manages, and terminates sessions between applications. • The Presentation Layer • Data encryption, data compression, data conversion • The Application Layer • Anything not provided by any of the other layers

  28. Connecting Network • Repeater: physical layer • Bridge: data link layer • Router: network layer • Gateway: network layer and above.

  29. Repeater • Copies bits from one network to another • Does not look at any bits • Allows the extension of a network beyond physical length limitations REPEATER

  30. Bridge • Copies frames from one network to another • Can operate selectively - does not copy all frames (must look at data-link headers). • Extends the network beyond physical length limitations. BRIDGE

  31. Router • Copies packets from one network to another. • Makes decisions about what route a packet should take (looks at network headers). ROUTER

  32. Gateway • Operates as a router • Data conversions above the network layer. • Conversions: encapsulation - use an intermediate network translation - connect different application protocols encrpyption - could be done by a gateway

  33. The Optical Era Will Provide Bandwidth Abundance • Decline in cost of key factors • During the industrial era: horsepower • Since the 1960s: semiconductors • Now: bandwidth • 40 million miles of fiber optic cable have been laid around the world, in the USA at a rate of 4,000 miles per day • Half of the cable is dark, that is, it is not used. And the other half is used to just one-millionth of its potential • Over the next decade, bandwidth will expand ten times as fast as computer power and completely transform the economy

  34. The Wireless Century Begins • The goal of wireless is to do everything we can do on wired networks, but without the wire • Wireless communications have been with us for some time • Mobile (cell) phones, pagers, VSATs, infrared networks, wireless LANs etc. • Radio waves are none-deterministic • The 20th century was the Wire-line Century, the 21st will be the Wireless Century

  35. Licensed VS. Unlicensed Frequencies • Some frequencies of the radio spectrum are licensed by governments for specific purposes; others are not • Devices that tap unlicensed frequencies are cheaper • No big licensing fees • Greater competition, more innovation and faster changes • Possibility of collision between signals

  36. "Telecoms Crash" • Auctions of the 3g radio spectrum in Germany and Britain at the beginning of 2000. • Although one similar auction in the USA had failed disastrously the year before. • 3G also requires an infrastructure development measured in billions of dollars • The nature of the auctions, was to offer a limited number of licenses • This put the telephone operators in a difficult position, as diabetics being forced to bid for insulin. • The stock market lost confidence (dot-com crash), influencing the credit rating of the operators • Within a year 100,000 jobs were lost in telecoms in Europe (30,000 in UK) • Subsequent government auctions of the 3g spectrum were met with low bids

  37. Wireless Networks (1) • Wireless Personal Area Networks (WPANs) • Provide high-speed connections between devices that are up to 30 feet apart • Wireless Local Area Networks (WLANs) • Provide access to corporate computers in office buildings, retail stores, or hospitals or access to Internet "hot spots" where people congregate • Wireless Metropolitan Area Networks (WMANs) • Provide connections in cities and campuses at distances up to 30 miles • Wireless Wide Area Networks (WWANs) • Provide broadband wireless connections over thousands of miles

  38. Wireless Networks (2)

  39. Wireless Long Distance (1) • The only two wireless technologies are infrared light and radio airwaves • Cell phone and cellular network • 1G cellular • Using analog technology and circuit switching • Main targeted at voice service • In the main, GSM has become the mobile telephony standard

  40. Wireless Long Distance (2) • 2G cellular • Predominant today, uses digital technology, but still circuit switched • 2G can carry SMS service • It aims at digital telephony, but with certain ability to carry data • 2.5G (e.g. GPRS)---2.75G (e.g. CDMA) • Adds data capacity to a 2G network • The problem with adoption has been pricing

  41. Wireless Long Distance (3) • 3G • Services include wide-area wireless voice telephony and broadband wireless data, all in a mobile environment. • 802.11 networks are short range • 384k-2M • Costs to deploy not seen as tenable in many circumstances • It faces the same pricing issues at 2.5G – perhaps worse • Killer apps still not clear • Battery and input

  42. Wireless Long Distance (4) • 4G • A comprehensive IP solution where voice, data and streamed multimedia can be given to users on an "Anytime, Anywhere" basis • Features • higher data rates than previous generations: 100M-1G (any two points in the world) • premium quality and high security • Fully IP-based • Supporting a greater number of wireless devices that are directly addressable and routable (IPv6) • Spectrally efficient and high network capacity • Pre-4G technologies • WiMax, LTE, UMB...

  43. Coming: An Internet of Things • Wireless communications like promised by 4G will enable machine-to-machine Internet • Sensor network • RFID tag • Devices are all connected to the Internet, with a mix of wired and wireless technologies • A new business environment

  44. The Role of the IS Department • Three roles of IS department • Create the telecom architecture • Connectivity • Interoperability • Operate the network • Stay current with the technology

  45. Conclusion • The telecom world is complex, and getting more complex every day • The business world is becoming increasingly dependent on telecom • In the past, electronic data exchange • The Internet unleashed email • Web sites were then used to get noticed globally • Now it is used for transaction and business • The first generation of the Internet economy has been wired. • The second is unwired

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