CS Principles U 1 L 3 Sending Binary

CS Principles U 1 L 3: Sending Binary Messages with the Internet Simulator

U 1 L 3: Sending Binary Messages with the Internet Simulator U 1 L 3 Objectives SWBAT: Explain how synchronization and coordination enable the transmission of binary messages. Develop a protocol for exchanging binary messages in two directions. Calculate the bit rate for a binary message exchange. Provide a definition of "bit" and relate it to the binary messages they have seen so far.

U 1 L 3 Content • The challenging problem of engineering a physical network for digital communications is that you must communicate in binary by setting the state of some object (such as a wire) to one of its two possible states. • Defining “State A” and “State B” is insufficient because there is no way to distinguish between a single bit "A" and a string of "AAA" for example. • Some element of time must be incorporated into a communication protocol to make it functional for exchanging bits. • This time-per-bit leads naturally to calculating a bitrate for a given device, or a measure of how quickly a system transmits digital data.

U 1 L 3 Vocab Bandwidth - Transmission capacity measure by bit rate Bit - A contraction of "Binary Digit"; the single unit of information in a computer, typically represented as a 0 or 1 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. Protocol - A set of rules governing the exchange or transmission of data between devices.

Getting Started Yesterday you all made your own binary message devices. We learned that we could compose any number of messages by sending a sequence of states. In order to interpret the message we needed to know which signal meant A and which meant B and some kind of mapping between sequences of signals and a possible message. What we were really doing was beginning to develop a communication protocol Today you're going to develop a protocol to solve a problem.

Binary Signal Test 1 "Your friend sends you this message. What is being signaled here? Write down what you think the message is. "

Binary Signal Test 2 "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. "

U 1 L 3 Prompt Did this new message make you think about your answer to the first question? Do you want to change your answer to the first question? What assumptions did you make in interpreting these messages? Is this protocol specific enough to allow useful communication of a binary message? If not what information would need to be added to it?

U 1 L 3 Activity: Internet Simulator Code to Code. org U 1 L 3 Stage 1 Download U 1 L 3 Coordination and Binary Messages Today we will be using the 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 they will need to problem solve around Internet Simulator - Part 1

Wires, Cable, and Wifi Watch the Video Wires, Cable and Wifi, and complete the Activity Guide: U 1 L 3 Wires, Cable, and Wifi