| Lab Name | 
How is Reliability affected by Obstacles?
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| Subject Area | 
Computer Science and Engineering
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| Grade | 
9 - 12
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| Topic | 
Wireless communications, obstacles, and noise.
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| Experiment Title | 
Measuring the power level at different electromagnetic frerquencies when different obstacles are blocking the transmitter
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| Hardware | 
	- Pairs of Walkie Talkies
 
	- CS IoT node pairs with XBee(900)
 
	- Primary Nodes (with Bunny Ears antenna)
 
	- Primary Nodes (with 900MHz antenna)
 
	- Smart Phone (2.4GHz wifi AP)
 
	- Smart Phone (5 GHz wifi AP)
 
	- 2 Android phones
 
	- CS IoT node with Infrared transmitter & receiver hardware
 
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| Software | 
	- COSMOS toolkit framework
 
	- GnuRadio file for reading power levels
 
	- Arduino XBee_Tx code
 
	- Arduino IR_Rx code
 
	- Arduino IR_Tx code
 
	- WiFi Analyzer app (for Android phone)
 
	- Hotspot ability (for 2 smartphones)
 
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| Number of Sessions to teach the topic  | 
2 sessions
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| Educational standards to be addressed | 
	- HS-PS4-1
 
	Use mathematical representations to support a claim regarding relationships among the period, frequency, wavelength, and speed of waves traveling and transferring energy (amplitude, frequency) in various media.
  
	- HS-ETS1-1
 
	Analyze a major global challenge to specify qualitative and quantitative criteria and constraints for solutions that account for societal needs and wants.
  
	- HS-ETS1-2
 
	Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering.
  
	- HS-ETS1-3
 
	Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics, as well as possible social, cultural, and environmental impacts.
  
 
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| COSMOS concepts to be used for the lab | 
Signal Strength, Electromagnetic Power, Noise, Attenuation of signal through air, Electromagnetic frequency, Relationship between signal strength and distance
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| K12 Educational Goals (How the educational goals are achieved through teaching using the experiment, how the topic is connected to the COSMOS concepts used) | 
 As students gather data about the distances that wireless messages will travel, they will be able to compare technologies and frequencies of those technologies to see an inverse relationship.
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| Short Description and Walk-through of the experiment | 
For each technology:
	- Each group is responsible for one specific technology.
 
	- Group sets up a receiver with a computer/GRC/Antenna.
 
	- Group's transmitter will send a signal out.
 
	- Group can read the Power level (in dBm) from the GRC program.
 
	- The obstacle will be placed in between the transmitter and receiver.
 
	- Group will take a measurement of Power WITHOUT the obstacle
 
	- Group will take a measurement of Power WITH obstacle.
 
	- Groups will cycle around the room to different obstacles.
 
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| Testbed mapping of the experiment  | 
	Instead of a map of the classroom/school, students could work off of a map of Harlem.
	Transmitters would be set at a central location of testbed.
	Every other node could be set as a receiver and power levels could be mapped from each node.
	The procedure could be executed using all of the different wireless technologies that a COSMOS node employs (i.e., 2.4GHz, 5 GHz, WiFi, LTE, etc)
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