2001: Homework assignment 1

• General instructions
• Material
• Assignment
• Returning

• Deadline: Tuesday 2.10.2001 at 4pm

Material

If you use other sources than the material mentioned below, add a reference list to your homework assignment!

• The coursebook
• "Satellite-Based Internet: A Tutorial" in course handouts.

Important information for all: Copyright basics for Web authors and users by Jukka Korpela

Assignment: The basics of Internet

1. Briefly tell about those people - who they are/were and what are their crowning achievements in telecommunications?

1. Alexander Graham Bell
2. Emile Baudot
3. Samuel Morse
4. Harry Nyquist
5. William Fothergill Cooke
6. Claude Shannon
7. Agner Erlang
8. Bob Metcalfe
9. Charles Wheatstone

2. Transmission media

1. List the main properties for each of the following transmission media: bandwidth, cost, purpose of use and approximated maximum wiring distance (without repeaters). Are there any special problems occuring when using each media?
   1. twisted pair
   2. coaxial cable
   3. optical fiber
   4. radio waves
   5. microwaves
2. About 10 years ago, the soviet occupation ended in Estonia. There is a story about building a LAN those days. A company had bought enough of good cable for cabling the company's new network. A clever technician thought he could save some money for the company, and instead of using the new expensive cable, he made a "new" cable of pieces of telephone wires and other cables mixed up and used it in cabling the LAN. The boss of the technician was very angry to him after finding out what had happended. Why?
   (Truthness of this legend is unconfirmed)
3. Choose the best alternative for each question.
   1. Providing satellite connection on Maldives is possible using
      1. GSO satellites
      2. LEO satellites
      3. both GSO and LEO satellites
      4. none of the above
   2. An antenna size needed for satellite transmission depends of
      1. transmission distance
      2. wavelength
      3. none of the above
   3. Resource wasting is a problem of
      1. DAMA
      2. USAT
      3. TDMA
   4. Which of these protocols will be probably leaved out in satellite-based Internet?
      1. TCP
      2. UDP
      3. both
      4. none of the above
   5. DT-DVTR works by
      1. making static routing look like dynamic routing for each time period
      2. making dynamic routing look like static routing for each time period
      3. using static and dynamic routing in different parts of a network

3. TCP/IP model

1. Link these terms to correct TCP/IP layers. Explain your choise.
   1. error correction
   2. routing
   3. Ethernet
   4. FTP
   5. bridge
   6. repeater
   7. NNTP
   8. UDP
2. Define the terms connectionless and connection-oriented protocol.
3. Why are layered models used for protocols?

4. Calculations

1. Bandwidth of fictional network is 4000 Hz and the number of signal levels is 4.
   1. Calculate maximum data rate in a noiseless channel.
   2. Signal/noise ratio of the network is 10 dB. Calculate maximum data rate of the channel.
2. Transmission channel between two terminals is made up of two sections. In the first section attentuation is 4.6 dB and in the second the attentuation is 5.2 dB. In a repeater between those sections the signal is amplified 3.8 dB. What should the power level of the signal in the beginning be if the receiver can't resolve signal below 200 mW?
   

5. Feedback

1. How many hours did you spend doing this assignment?
2. Was the assignment too hard or too easy? Why?
3. What topics should this assignment cover next year?

Returning your answer