This lesson introduces how bits are transmitted over the most common mediums (copper wire, fiber-optic cable, and radio waves) used to connect devices on the Internet. You will choose a device that transmits bits, then research that device and the system it uses. Your end product will be a poster presenting your findings. The class will have a gallery walk of all posters.
Students will be able to:
- Differentiate between three common methods for transmitting bits across the Internet
- Identify how household items use these technologies to send, receive, or store information
Binary information must be encoded in some way before transmission over the Internet. There are a few methods for encoding bits that are used far more often than others. Copper wire is used to transmit binary messages using electricity - a voltage on the wire means one state, and no voltage means the other. Fiber-optic cables, on the other hand, use light (on or off) to transmit a binary message. Radio waves can be used to send binary information by altering the frequency or amplitude of the wave. Together these different systems form the network of bit-sending devices we know as the Internet. A single bit sent from a cell phone in North America to someone in China probably travels over radio waves, fiber-optic cable, and copper wire before it reaches its destination.
- Worksheet in Large Print - Video Guide for "Wires, Cables & WiFi"
- Worksheet in Braille .dxb - Video Guide for "Wires, Cables & WiFi"
- Worksheet in Braille .brf - Video Guide for "Wires, Cables & WiFi"
- Activity Guide in large print
- Activity Guide in braille, Duxbury file
- Activity Guide in braille, .brf
- Rubric for the Activity in large print
- Rubric for the Activity in braille, Duxbury file
- Rubric for the Activity in braille, .brf
Use the worksheet to take notes on the video, of you have not already done so. After the video, respond to the prompt below.
- For each medium (copper wire, fiber-optic cable, and radio waves), how is the information encoded?
- Why are all three methods of sending bits used? Why isn't there one "best" way of sending bits across the Internet? Provide instances when you'd want to use one method vs. another.
Using the activity guide and rubric, we're going to use our new understandings of how bits travel across the Internet to learn more about bit sending devices we use every day. You will choose a familiar digital device that transmits information and research which bit sending technology it uses. Once you've completed your research you'll be asked to create a poster to present your findings to your classmates.
Mix it up! Try to choose different devices, so the gallery walk will be more interesting. Also, you might need to use more than one source to find your information. That's ok!
When you finish your poster, display it in the room for the Gallery Walk. During the Gallery Walk, complete the Reflection portion of your rubric.
1. Match each bit-sending technology (numbers) with the underlying system (letters).
- 1. Copper Wire
- 2. Fiber Optic Cable
- 3. Radio Waves
- A. Beams of Light
- B. Alternating Frequencies
- C. Electric Voltage
2. Choose a bit sending technology you learned about today (electricity, light, radio waves) and describe the pros and cons of using this technology.
3. Describe how a single bit might be transmitted from a laptop in a coffee shop in Chicago, to someone's phone in China. How is a single bit physically transmitted from one place to another?
- James May addresses the need for and use of protocols in communicating across different devices
- Science Scrapbook explores the physical systems/networks, protocols, and routes that information must navigate in order to be transmitted from one device to another
- Andrew Blum TED talk about the physical Internet and how it works
Blown to Bits
- Read Blown to Bits, Chapter 8, Bits in the Air, pp. 260-272 (How Broadcasting Became Regulated). Then answer the following questions.
- What early regulatory body later became the FCC?
- What mediums are now under their oversight?
- Should the FCC regulate additional mediums, such as the variety of electronic mediums that have sprung up in the digital era? Why or why not?
- CSTA K-12 Computer Science Standards: CD.L2:6, CD.L3A:9
- CSTA K-12 Computer Science Standards: CI.L3B:2, CI.L3B:4
- Computer Science Principles: 2.1.1 (A, B, C, E)
- Computer Science Principles: 2.1.2 (D, E, F)
- Computer Science Principles: 3.3.1 (A, B)
- Computer Science Principles: 6.1.1 (A, B, C, D)
- Computer Science Principles: 6.2.1 (A, D)
- Computer Science Principles: 6.2.2 (A, B, C, E, F, G, H, I, J, K)