U1Ch1L3: Developing A Protocol (Sending Binary Messages With The Internet Simulator) Purpose: Students will learn how to develop a Protocol in order to solve a problem. Vocabulary: (Give each student/partner a word to define and explain. They will provide to other students) Protocol - A set of rules governing the exchange or transmission of data between devices. Bit – Short for "Binary Digit"; the single unit of information in a computer, typically represented as a 0 or 1. Byte – A Byte is 8 Bits. Bandwidth - Transmission capacity measure by bit rate (think of different pipe sizes.). Bit rate - (sometimes written bitrate) the number of bits that are conveyed or processed per unit of time. e.g. 8 bits/sec. Latency - Time it takes for a bit to travel from its sender to its receiver.

Intro:
Yesterday you made a Device and developed a Process to communicate your own binary message. In order to interpret the message we needed to know which signal meant A and which meant B. What we were really doing was beginning to develop a communication Protocol. Today you’re going to develop a protocol to solve a problem.

 Journal Entry: Give each student/partner a vocabulary word from the list above to define and explain. They will provide to other students.

Flashlight Binary Signal!
Instructions:

• “Imagine that you and your friend have made a binary signaling protocol using a flashlight. The light on is letter “A”, off is letter “B.”  
• One student is the transmitter and sends a message with a flashlight.
• One student is the receiver and decodes the binary message.

Challenge #1 - Transmitting simple Binary Code.
“Imagine that you and your friend have made a binary signaling protocol using a flashlight. The light on is letter “A”, off is letter “B.”  

• Protocol: The Transmitter shall pulse the flash light on and off at ~1 second intervals 4 times.
• The Transmitter and Receiver should take a moment to practice with both the Device & Protocol.
• The Instructor will provide the Transmitting Student with the a code.
• Your partner sends you this code. What is being signaled here? Write down what you think the message says.”
  Students can check to see if it matches the code that was provided to the Transmitter.
• Should the protocol be rewritten?

Challenge #2 - Transmitting more complex Binary Code.
“Uh oh! Your friend realizes she actually made a mistake encoding the message from before and decides to re-send the message. Decode this new version of the message and write it down.”

• The instructor will provide the students with a new code.
• Students should once again transmit and receive.
• Did it work?
• Should the protocol be rewritten?
  

Developing Protocols Using An Internet Simulator
Today we will be using an Internet Simulator to explore some of the challenges of sending bits on the Internet. This tool simulates a single wire connecting two people who cannot otherwise see or speak to each other. The Internet Simulator helps to enforce “the binary rule” for sending messages – it will present challenges that you will need to problem solve around.

Video: Video: How to use the Internet Simulator Tool Tutorial

Accessing the Internet Simulator:

• Go to the CSP Class Web Page and click on the Link to Code.org Student Accounts:   https://studio.code.org/join/MBSFQB
• Click on your name
• Select stage 3 (U1Ch1L3) and click on: Internet Simulator: Sending Binary Messages
• Select ok
• Then select a partner from the class list. ("Join" / "Accept")

Step #1: All the students should write a Binary Question (one question with two answers - the answers should have "A"& "B" attached to the respective answers.); Eg. Do you prefer to travel by car or plane? Partners will agree on the first Binary Question with accompanying answers they will use first.

Step #2: Partners should agree on who is going first. The Sender types in their answer to the Binary Question with an "A"or "B". and selects “Send”. The Receiver clicks  “Read,” states the letter that they received and the corresponding answer.

The challenge in this activity is making sure that when the “Sender” puts out a message, the “Receiver” is listening. Partners need to agree to who is going first. That person can then send their answer. – They should talk out loud so that each partner knows when they need to act.

Step #3: The Receiver now types in their answer with a "A" or "B"and “clicks”“Send.” The Sender clicks  “Read,” states the letter that they received and the corresponding answer.
Note: Start this activity without the pressure of a Timer! Eventually you can begin using the metronome as your timer.

Continue...
The Sender and Receiver will ask and answer a new question...
After several successful rounds, regroup and try to increase the speed by eliminating the talking. The partners should edit the protocols so that this new goal is achievable (eventually try to Send 2 Bit and finally 3Bit answers – make sure you rewrite the protocols. You should factor in plenty of transition time – a timeline may help.).
Try for 15 min.
Hint: If you pre enter you’re A &Bs, and use the Enter key…it is faster to send off.

Watch the following video so that you can see how others came to successfully use the simulator. Remember…it is all about Timing & Synchronization! You need to write your own rules or protocols to make it work.
Video: “An example of how the Internet Simulator is being used..” (link is on Class Website – Start at 34 sec.)

Journal: How did you and your partner rewrite your protocol to have a more successful discussion on the Internet Simulator. (With Partner Explain!)