IST 220 Networking and Telecommunications, Section 03, Midterm 2 Review

Exam Rules

1. The exam will be held at 1:25-2:15pm (class time), on Wednesday 10/30, in E203 Westgate. Try to come to class a few minutes early. Exam starts right at 1:25pm.

2. The exam is close book and close notes. You can bring one double-sided letter-size cheat sheet. Letter size (8.5" x 11") is the most common printing paper size.

3. You should bring your own calculator to the exam. No computer or other digital device is allowed.

4. You should sit at your assigned seat during the exam. The seat assignment will be displayed on the screen before the exam.

5. Turn in your midterm exam paper AND the cheat sheet.

6. There will be NO make-up examinations unless an official excuse (document) is submitted and pre-approved by the instructor.

Exam Content

Note: The points below are for your reference only and are subject to change.


          Part 1. Choose ONE from the multiple choices. (15 points)

          Part 2. True or False. (20 points)

          Part 3. Short answer questions. (65 points)

Key Points in Each Chapter


o         This exam covers Chapters 10, 11, 13 (including Section 14.6.2 for CDMA/CD), 15, and 17.

o         All the exam contents are covered in our slides. We will not test the contents in the textbook but are not in slides. However, if you have problems in understanding the slides, you need to refer to the textbook. The corresponding section numbers and key points in the textbook are listed below.

o         All slides can be downloaded from the course website. To prepare for the exam, you should carefully go through all the slides. Re-do the exercises in the slides.

o         Pay special attention to the homework assignment questions (all questions). The solution will be posted on Canvas after the submission deadline. Carefully compare your answers with the solution, and learn from the mistakes.

Chapter 10. Modulation and Modems

          Sections covered: 10.1 – 10.12


o         What are modulation and demodulation

o         Why do we need this technology

          FM, AM

o         How do they work

          FSK, ASK, PSK

o         How do they work

o         Know how to draw the resulting waveform after each type of modulation

o         Efficiency issues of ASK and FSK

o         Know how to calculate phase shift

o         Phase shift and constellation diagrams

          Modem: What is it

Chapter 11. Multiplexing and Demultiplexing

          Sections covered: 11.1 – 11.13, 11.15 -- 11.16


o         What are multiplexing and demultiplexing

o         Why do we need this technology


o         How does it work

o         What are its advantages and disadvantages

o         Why using a range of frequencies per channel


o         What is synchronized TDM? What problem does it have?

o         How does statistical TDM work?


o         How to determine if two vectors are orthogonal

o         How does CDM work? Know how to calculate the final signals to be sent through the shared media

o         What are its advantages and disadvantages

Chapter 13. Local Area Networks (LAN)

          Sections covered: 13.1 – 13.12

          Circuit switching vs. packet switching

o         What are they? How do they work?

o         Pros and cons

          MAC addresses

o         The structure of MAC address

o         Know how to use ipconfig to find the MAC address of a computer

          Number systems

o         Know how to convert binary/hexadecimal to decimal

o         Know how to convert decimal to binary/hexadecimal

          Frames: layer-2 packets

o         Composition of a frame: header, payload, SOH, EOT, CRC

          LAN Topologies

o         Types and their pros/cons

o         Star topology

          Steps to send a message in a network using star topology (with a switch)

o         Bus topology

          Steps to send a message in a network using bus topology

          CSMA/CD: what is it; how does it work (also see Section 14.6.2 of textbook )

Chapter 15. Wired LAN Technology (Ethernet and 802.3)

          Sections covered: 15.1 – 15.4, 15.6 – 15.12

          Ethernet frame format

o         Type field

          Three major versions of Ethernet wiring

o         Know the differences among thicknet wiring (1 st gen), thinnet wiring (2 nd gen), and twisted pair Ethernet wiring (3 rd gen)

o         Know the cable type for each version

o         Know the pros and cons of each version

o         Variants of twisted pair Ethernet wiring and their data rates

          Hubs vs. switches

o         What is a hub?

o         What’s the difference between hubs and switches?

o         What is the logical topology of a hub?

Chapter 17. LAN Extensions

          Sections covered: 17.1 – 17.5, 17.7, 17.9

          Fiber modem extensions

o         What is it? Pros and cons?


o         How does it work?

o         Pros and cons?


o         How does it work? Why does it work well in practice?

o         Steps to send a message in a networking with bridges


o         What is a switch?

o         Switches vs. bridges