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MD253 - E-Commerce

MD253 - E-Commerce. Module 1: A World Connected Spring 2003 The Internet, consumer devices, iTV How the Internet Works Telecom: an Industry in Crisis Solving the Last Mile Problem Mobile & Wireless Emerging & Key Technologies. What is the Internet?. A Network of Networks

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MD253 - E-Commerce

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  1. MD253 - E-Commerce Module 1: A World Connected Spring 2003 The Internet, consumer devices, iTV How the Internet Works Telecom: an Industry in Crisis Solving the Last Mile Problem Mobile & Wireless Emerging & Key Technologies

  2. What is the Internet? • A Network of Networks • TCP/IP - standard protocol for routing & transport • A medium of exchanging all form of digital data • text, graphics, audio, video, programs, faxes • An infrastructure for various services • e-mail (electronic mail) • WWW (world wide web) • FTP (file transfer protocol) • UseNet newsgroups • Games, EDI, etc.

  3. How Many Online? source: nua.ie

  4. BSkyB Moxi TiVo xbox Lyra Samsung Media Center Smart Display AOLtv Replay Ultimate TV XP Media Center

  5. Transmission Speeds • Bandwidth • measure of transmission speed / capacity • Bits & Bytes • bit - smallest form of computer memory - 1 or 0 • byte - 8 bits, roughly 1 character (Latin alphabet) • How do we measure speeds? • bps - bits per second • Kbps - kilobit, thousands of bits per second • Mbps - megabit, millions of bits per second • Gbps - gigabit, billions of bits per second

  6. Anatomy of a URL • URL • Uniform Resource Locator (web address) http://www2.bc.edu/~gallaugh/directory/file.html application protocol (http is assumed by current browsers). Others: FTP, NNTP host computer (others @ BC: agora, www) domain name, top level domain user ID directory file case sensitive

  7. The DNS & IP Addresses • IP Address • Unique number identifying Internet computers. Expressed as four numbers between 0 and 255. • ex: www.bc.edu = 136.167.2.72 (32 bit address) • IPv6: 128 bit addressing, more efficient/faster, secure • DNS - Domain Name Service • A distributed database used to translate host/domain names, into Internet Protocol (IP) Addresses. • Registry of an Internet domain name: • for com, net, org, over 60 firms (see icann.org for list) • for country-specific domains (.jp,.uk, .tv) fees vary widely (see icann.org for list)

  8. R R Network Interconnections dial-in users (56.6 Kbps) dorm users class/office users web server www2.bc.edu modem pool dorm LAN office LAN wireless BC Campus Network Backbone (10 Mbps) (IP #s 136.167.xxx.xxx domain) Internet Leased Line through our ISPs (45 Mbps / T3) The Internet microsoft.com local ISP whitehouse.gov

  9. TCP/IP • TCP/IP - the Internet’s common language • TCP - Transmission Control Protocol. Breaks up transmissions (e-mail messages, web pages, etc.) into packets of no more than about 1500 characters each, checks the integrity of incoming packets, and reassembles packets on the other end • IP - Internet Protocol. Routes packets.

  10. Packet Traffic • What’s in a packet? • source address • destination address • error checking (checksum) • time to live • options (timestamp, record route, etc.) • your data!

  11. R R R R R R A Packet Switched Network at Work packet1 E-mail message: Prof. Gallaugher, I just wanted to let you know that I got a job based on the stuff I learned in your class... E-mail message: Prof. Gallaugher, I just wanted to let you know ... packet1 packet2 packet2 packet1 packet3 packet3 packet2 packet2 packet3 packet3 = router

  12. US Internet Infrastructure Watch Cable & Wireless’s backbone traffic at: traffic.cwusa.com Source: lbrandt@nsf.gov

  13. TCP vs. UDP TCP - perfect transmission is critical (e.g. e-mail) TCP will request packets that are lost or damaged The Internet UDP = User Datagram Protocol UDP - low latency is critical (e.g. streaming audio, video) Latency matters - UDP will ignore packets that don’t arrive on time or in good shape The Internet

  14. Circuit vs. IP Telephony Circuit Switching Guaranteed QoS (quality of service) Internet Telephony (e.g. Vonage, Net2Phone) packets over the Internet, variable QoS The Internet IP Telephony over Private Networks (e.g. corporate VoIP, Qwest) packets over private network, improved QoS Private IP Network

  15. 87% Decline in InternationalDS-3 Pricing over the past two years Source: BandXChange

  16. 67% Decline in Domestic DS-3 Pricing over the past two years Source: BandXChange

  17. The Last Mile Problem • The contenders • Cable Modems (cable firms) • Tech limits:congestion (shared capacity with local users) • DSL (RBOCs & those leasing capacity) • Tech limits:distance (must be 3.5 miles from central office for ADSL), home wiring limitations • Terrestrial Fixed Wireless (WorldCom, Sprint, others) • Tech limits: line-of-sight, rain fade, antennas, congestion • GEO Satellite (Hughes, EchoStar) • Tech limits: slower transmission, latency, need dish, line-of-sight, congestion

  18. i-Mode’s Rocket Ride

  19. Europe poor technology “walled gardens” enormous capital outlays Japan packet-switched, always on, HTML standards, java open platform 3G licenses offered for free via “beauty contests” Mobile Contrasts

  20. Emerging Wireless Technologies • Wi-Fi • 802.11b – LAN replacement, 11 Mbps, 150-300 ft., crowded, unregulated 2.4 GHz spectrum • 802.11a (Wi-Fi 5) – 54 Mbps, similar range, less crowded 5 GHz spectrum, 802.11g – 54 Mbps, rev. compatible w/(b) • Bluetooth • Cable replacement technology • 400-700 Kbps, 30-33 ft., unregulated 2.4 GHz spectrum • UWB – Ultra Wide Band • 100 Mbps+, 30 ft., multiple spectra (licensed & unregulated) • RFID • Tracking, payment, bar-code replacement • Current high cost $1-$2+, privacy concerns

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