Class Notes for Session1/TDC 461


  1. Introduction to Course
    1. Course Overview
      1. What you'll get out of this course:
        1. Basic concepts and info
        2. Sense of the real world application of telecom
        3. Heightened awareness of legal/social issues surrounding telecom technologies
        4. Ability to use your knowledge to evaluate proposed systems for feasibility and "fit
      2. What do you want to get out of this course. Please take a moment during the break or when you start to nod off in class to write down what you would like to get out of this course. Turn these in at the end of the evening and I'll come back with a "Top 10" list on Wednesday and some strategies for addressing your needs.
      3. Syllabus Overview
        1. How to reach me
        2. Office hours and appointments
        3. Grade components: Exams
          1. Both exams are take home
          2. Exams are open book, but not group work
          3. Exams must be wordprocessed and e-mailed as an attachment or turned in as hard copy by specified deadlines. Exams may be turned in early, but not late.
        4. Schedule
        5. My expectations of you
      4. Class HyperNews Group:
      5. Class web site:
      6. Class stuff: we will meet for at least three hours each class meeting time, with a break sometime between 7:15 and 7:30 each evening.
  2. Introduction to Telecommunications
    1. Definition=>the electronic communication of information over distance.
    2. Information:
      1. Voice
      2. Data
      3. Video
      4. Integrated Information (voice AND video AND data)
    3. Problems that spurred telecommunications development
      1. Problems of physical distance
      2. Problems of physical barriers
    4. Quality Measures of Telecommunications Systems
      1. Cost:
      2. Efficiency:
      3. Quality:
      4. Time:
      5. Ease of Use:
    5. Problems in Telecommunications
      1. Legacy Systems
      2. Communications Standards
  3. Brief History of Telecommunications
    1. Axiom: most major advances in telecommunications come as preparation for or a result of wartime action.
    2. Communication before 1830--what did it look like?
    3. 1830-1870s: What was going on in the world?
      1. How did world events impact telecommunications?
      2. What telecom inventions came out of this period of time?
    4. 1870s-1920s
      1. World events?
      2. Technology breakthroughs?
      3. Technology regulation?
    5. 1930s -1940s
      1. World events?
      2. Technology breakthroughs?
      3. Regulatory environment?
    6. 1950s-1960s
      1. World events?
      2. Technology breakthroughs?
      3. Regulatory environment?
    7. 1970s-1980s
      1. World events?
      2. Technology breakthroughs?
      3. Regulatory environment
    8. 1990s
      1. World events?
      2. Technology breakthroughs?
      3. Regulatory environment?
    9. Some things to keep in mind:
      1. Technology is developed in four big stages:
        1. Stage 1:
        2. Stage 2:
        3. Stage 3:
        4. Stage 4:
      2. This historical life cycle is about 70 years. We’re just now ready to see a new revolution.
  4. Voice Characteristics
      1. What do we know about human sound?
        1. What is sound?
        2. How do humans produce sound?
          1. Compression
          2. Rarefaction
          3. Frequency
          4. Amplitude
        3. What is the physical nature of the human voice?
      2. What do we know about electronic sound?
        1. How is human sound transmitted between two locations over a wire?
        2. What is the physical nature or wave of that sound?
      3. Components of sound production, hearing, and the telephone system
        1. One Hertz equals one 360 ° cycle around a central point
        2. Human voice creates 100-5000 cycles per second, or 5kHz
        3. Analog waves (sinusoidal)
        4. Human ear responsiveness:
        5. Telephone system infrastructure
          1. POTS line capabilities
          2. Bandpass filter/band-limited channel
      4. Bandwidth
          1. Size of pipe
          2. Speed of "stuff"
      5. Limitations of voice, analog signals, and bandwidth
  5. Trends in Telecommunications
    1. Continued Deregulation
      1. Regulation of use/abuse of telecommunications network
        1. Wiretapping
        2. Abuse provisions
        3. Enforcement remains a huge problem
      2. Communications Act of 1996
        1. Deregulation of local telephone service
        2. Deregulation of communication services
          1. Cable TV providers
          2. Data connectivity providers
          3. Long distance providers
          4. Local telephone service providers (dial tone)
          5. Local long-distance providers
    2. Local and Wide Area Networks
      1. New and enhanced services over the Public Switched Telephone Network (PSTN)
        1. Voice mail, e-mail
        2. Secure communications is becoming a standard service option
        3. Expanded voice services=>caller ID, call waiting, auto-call-back, 3-way calling
        4. Expanded data networking--telcos now provide many local- and wide-area-network functions and services
        5. Interactive Video
        6. Electronic Shopping
      2. ISDN (Integrated Services Digital Network)
        1. Basic Rate Interface (BRI) provisioned as two 64kb B (information bearer) channels and one 16kb D (data) channel for control (network management, signalling and packetizing).
        2. B channels can be aggregated to form one 128kb channel.
      3. Faster, more efficient transport media
        1. Fiber optics
        2. Copper
          1. Shielded twisted pair (STP)
          2. Unshielded twisted pair (UTP)
        3. T-Carrier System being converted to the Optical Carrier (OC) system (move from copper to fiber)
          1. T1 circuit provides 1.544 Mbps (also known as DS-0 (digital signal zero)
          2. T3 circuit provides 45 Mpbs (also known as DS-3)
          3. OC-1 circuit provides 51.84 Mpbs and is generally viewed as equivalent in service to one DS-3 circuit.
          4. OC-3 circuit provides 155.52 Mbps and is equivalent to 3 DS-3 circuits.
        4. ISDN
        5. Land-based (terrestrial) microwave systems
    3. Standardization of Protocols
      1. Open Systems Interconnect (OSI) model
        1. 7-layer model for developing hardware and software services for any network (LAN, MAN, WAN) to ensure interconnectivity.
      2. ISO Standards
        1. X.400 for Internet addressing
        2. X.500 for directory services (white pages) standards
    4. Wireless Communications
      1. Cellular: industry anticipates growth from 4 million U.S. customers in 1990 to 33 million in 2000.
      2. Personal Communications networks
    5. Trend 5: Expansion of Video Conferencing
      1. Speed of transmission increasing
      2. Compression algorithms and CODEC (coder/decoder) equipment getting better
    6. Trend 6: Improvement of Voice Processing
      1. Voice synthesis: input is text or data; output is voice
      2. Voice recognition: input is voice; output is text, data, other.
    7. Trend 7: Information as a Strategic Resource
      1. Moving away from use of data to explain why things happened to using data to predict what will happen.
      2. Development of Executive Information Systems (EISs) and Decision Support Systems (DSSs) that project implications of decisions, strategies, and other business changes before the changes and implemented.