Digital Escape Room

• One room per group
• Each room needs a computer connected to the internet (Stored in Google Golab) and a projector to display the videos and the virtual escape room.
  • https://colab.research.google.com/drive/1i3-SvRIznnZOISXM6cpXFgPETJ1j1zFj?hl=es#scrollTo=7xQeKLDCg5Ve

• The activity is a digital escape room. The game has three rooms for two hours (it can be extended for more time). 
• Each room has an introductory video of about 7 minutes explaining one of the communication blocks (sampling and digitization, channel coding, and modulation, respectively).
• The story is about a scientific group that discovered a universal vaccine to COVID-19 and need to communicate with their peers in the world, but they are trapped because of an earth-quake: There is a short video of 2 minutes explaining that. Thus, they must build the communication link for transmitting the information. 
• After the video in each room, they have to solve the puzzles in the room using the knowledge they had just learned. 
• The first room is sampling and digitization where they learn why they need to sample and digitalize information and the main concepts on that such as sampling rate, Nyquist, bps, memory needed, resolution…. In this first room, they also learn the main block diagram for a generic communication link.

At the room’s computer, open a browser and open the google collab. Go to “Environment” and Run All

1. Room 1

   At first Room, you have to press “Comenzar” (Start) And read the description of the room, look for the clues and once you know, the puzzle in collab has 3 bars you can move. This is the code.

   The first one indicates the memory for document 1 and you can move the bar for the correct sampling frequency.

   Since the document 1 has higher resolution than 2, it means that you need to use a higher sampling frequency in document 1. How much, the maximum memory.

   The second bar is for document 2. the same, memory and sampling frequency. Since document 2 is lower resolution, you need to move the bar for the 2 at Nyquist, this is, twice the maxium frequency of the document you can see in the spectrugram above for document 2.

   The temperature bar is flexible and is between 20º to 40ºC.

   Then, you press “SALIR SALA 1” (exit from room 1)

   Copy the code you get to introduce as input in the next room.

2. Room 2

   Put the code and press “Entrar en sala 2” (enter in room 2)

   You will find some binary sequences coming up. One in blue, whihc represents the input sequence. One in green, the correct encoded sequence from  input sequence, and a red one, which is an erroneous encoded sequence.

   You need to figure out that green is the correct one, and see that it comes from input bit (blue one).

   Dividing in three blocks because using the clues you can figure out that it is a convolutional cod, with 3 outputs, and three registers. You need to figure out the encode code. The swiches represents wether the wire is conected or not into the code.

   The solution is switch 11 and 12 on for the first part, and switch 21 and 23 onn.

3. Room 3

   Put the code and press “Entrar en sala 3” (enter in room 3).

   With the BER graphic you need to figure out that the target BER is 1e-4 (indicated in the figure), and see the different modulations and eb/B0 that you need to obtain this BER.

   And then, selecting a especific modulation for each Eb/N0 and the correct number of bits transmitted for this modulation.

   The solution is:

   15: 8PSK 3

   20:16PSK 4

   5: QPSK 2

   10: QPSK 2

   22: 32PSK 5

   17: 16PSK 4

   25: 32PSK 5

   13:8PSK 3

   And press “Transmitir” (transmit)

   You are out, congratulations.

Thanks to the IEEE Communications Society (ComSoc) and it’s members who created this hands-on activity:

• Victor P Gil Jimenez, Universidad Carlos III de Madrid, Spain