Lab Name Relationship between Independent and Dependent Variables Using Experiment Connecting Distance and Wireless Signal Strength.
Subject Area Mathematics
Grade 7
Topic Investigating the relationship between Independent and Dependent Variables.
Experiment Title Measuring the Strength of different Signals changing locations (indoor & outdoor) and using the data gathered by analyzing results.
Hardware
  • COSMOS Toolkit: Computer Node
  • COSMOS Toolkit: Mobile Node
  • Software Defined Radio (i.e., ADALM Pluto SDR, RTL-SDR)
  • Additional Transmitter (i.e., Walkie-Talkie, baby monitor, car key, or a radio control toy)
Software
  • COSMOS Toolkit: Framework
  • GNU Radio Companion
Number of Sessions to teach the topic 5 - 6 sessions
Educational standards to be addressed 7.RP.2.a, b, c, d
Recognize and represent proportional relationships between quantities.

7.EE.B.4
Use variables to represent quantities in a real-world or mathematical problem, and construct simple equations and inequalities to solve problems by reasoning about the quantities.
COSMOS concepts to be used for the lab Wireless signals, attenuation of the signal over the air, signal strength indoor/outdoor, relationship between signal strength and distance.
K12 Educational Goals (How the educational goals are achieved through teaching using the experiment, how the topic is connected to the COSMOS concepts used) Teaching relationship between independent and dependent variables by observing the relationship between signal strength and distance.
Short Description and Walk-through of the experiment
  • Outdoor:
    • Transmit the signal through a Pluto SDR and receive it through another SDR.
    • Repeat the same experiment using different distances, collect the results and analyze them.
  • Indoor:
    • Repeat the same experiment or the same procedure.
    • Repeat the over-all procedure using different transmitters( walkie-talkie, baby monitors, etc)
Testbed mapping of the experiment The experiment can be extended by executing it into a testbed (ORBIT/COSMOS) through the following steps:
We define a particular node as the receiver and we change the nodes we use as transmitters. In this way, we perform the experiment using nodes in different locations and we observe the relationship between signal strength and distance or even more in the presence of external interference moving obstacles in the area like cars, etc.

Experiment Execution

Select the appropriate function or the node (i.e., Transmitter or Receiver) and press START to begin the experiment. In order to terminate the experiment press STOP.
Transmitter Receiver

Experiment Material

NGSS Lesson Plan
Worksheet
Other

© 2018 COSMOS Project. Created by Juditha Capa Damiao, Joseph F. Lamb School
Melissa Sanchez, Urban Assembly Academy for Future Leaders
Deidre Walker, New York Harbor School