Why mesh networks for IoT in IOT Protocols - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a mesh network node that can connect to multiple neighbors.

IOT Protocols

node = MeshNode(connections=[1])

Drag options to blanks, or click blank then click option'

A['neighbor1', 'neighbor2']

B'single_neighbor'

CNone

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using a single string instead of a list

Setting connections to None or 0

Mesh nodes connect to multiple neighbors to create a network where data can hop between devices.

2fill in blank

medium

Complete the code to send a message through the mesh network.

IOT Protocols

mesh.send_message(destination=[1], message='Hello')

Drag options to blanks, or click blank then click option'

A'device_5'

Bmesh

CNone

Dbroadcast

Attempts:

3 left

💡 Hint

Common Mistakes

Using broadcast instead of a device ID

Passing None or the mesh object

Messages are sent to a specific device identified by its ID in quotes.

3fill in blank

hard

Fix the error in the code to correctly add a new node to the mesh network.

IOT Protocols

mesh.add_node([1])

Drag options to blanks, or click blank then click option'

A3

Badd_node('node_3')

C'node_3'

DNode('node_3')

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a string instead of a Node object

Passing an integer or calling add_node inside add_node

Adding a node requires creating a Node object with its ID.

4fill in blank

hard

Fill both blanks to create a function that checks if a node is reachable in the mesh network.

IOT Protocols

def is_reachable(node_id):
    return node_id [1] mesh.nodes and mesh.nodes[node_id].status [2] True

Drag options to blanks, or click blank then click option'

Ain

B==

C!=

Dnot in

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'not in' instead of 'in'

Using '!=' instead of '=='

The function checks if the node ID is in the mesh nodes and if its status is True (reachable).

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps node IDs to their signal strength if above a threshold.

IOT Protocols

strong_signals = {node_id: mesh.nodes[node_id].[1] for node_id in mesh.nodes if mesh.nodes[node_id].[2] [3] 50}

Drag options to blanks, or click blank then click option'

Asignal_strength

C>

D50

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong attribute names

Using '<' instead of '>'

Missing the threshold value

This comprehension collects signal strengths for nodes with strength greater than 50.

Practice

1. Why are mesh networks preferred for IoT devices over large areas?

easy

A. Because they use more power to keep devices always active.

B. Because they allow devices to communicate through multiple paths, increasing reliability.

C. Because they require a central hub to manage all communications.

D. Because they limit the number of devices that can connect.

Solution

1. Step 1: Understand mesh network communication

   Mesh networks let devices connect through many paths, not just one direct link.

2. Step 2: Identify benefit for large areas

   This multiple-path setup means if one device fails, data can still travel another way, making communication reliable over large areas.

3. Final Answer:

   Because they allow devices to communicate through multiple paths, increasing reliability. -> Option B

4. Quick Check:

   Multiple paths = Reliable communication [OK]

Hint: Mesh means many paths for data, so more reliability [OK]

Common Mistakes:

• Thinking mesh needs a central hub
• Assuming mesh uses more power
• Believing mesh limits device count

2. Which of the following is the correct feature of mesh networks in IoT?

easy

A. Devices communicate only with a central router.

B. Devices cannot add new members once network is set.

C. Devices must be physically connected by wires.

D. Devices can forward data for other devices.

Solution

1. Step 1: Recall mesh network feature

   In mesh networks, devices can pass data along to other devices, acting as repeaters.

2. Step 2: Eliminate incorrect options

   Devices communicate only with a central router. is wrong because mesh does not rely on a central router. Devices must be physically connected by wires. is wrong because mesh is wireless. Devices cannot add new members once network is set. is wrong because mesh networks allow easy addition of new devices.

3. Final Answer:

   Devices can forward data for other devices. -> Option D

4. Quick Check:

   Forwarding data = Mesh feature [OK]

Hint: Mesh devices help each other by forwarding data [OK]

Common Mistakes:

• Thinking mesh needs wires
• Believing mesh uses a central router
• Assuming mesh networks are fixed size

3. Consider a mesh network where device A sends data to device D through devices B and C. If device C fails, what happens?

medium

A. Data is rerouted through another path if available.

B. Data from A to D stops completely.

C. Device A must restart to send data again.

D. Device D sends data back to device A.

Solution

1. Step 1: Understand mesh network routing

   Mesh networks have multiple paths. If one device fails, data can find another route.

2. Step 2: Apply to failure scenario

   When device C fails, the network tries alternate paths from A to D to keep data flowing.

3. Final Answer:

   Data is rerouted through another path if available. -> Option A

4. Quick Check:

   Mesh reroutes data on failure [OK]

Hint: Mesh finds new paths if one device fails [OK]

Common Mistakes:

• Assuming data stops immediately
• Thinking devices must restart
• Confusing data direction

4. A mesh network is not forwarding data correctly. Which is the most likely cause?

medium

A. The network has too many devices.

B. The central router is down.

C. Devices are too far apart to communicate.

D. Devices are wired incorrectly.

Solution

1. Step 1: Identify common mesh network issues

   Mesh networks rely on devices being close enough to communicate wirelessly.

2. Step 2: Analyze given options

   The central router is down. is invalid because mesh networks do not depend on a central router. Devices are wired incorrectly. is invalid because mesh is wireless. The network has too many devices. is unlikely to cause forwarding failure directly.

3. Final Answer:

   Devices are too far apart to communicate. -> Option C

4. Quick Check:

   Distance too far = communication failure [OK]

Hint: Check device distance first if mesh fails [OK]

Common Mistakes:

• Blaming central router in mesh
• Thinking mesh needs wires
• Assuming device count breaks mesh

5. You want to add 50 new IoT sensors to a mesh network covering a large farm. Which advantage of mesh networks helps this task the most?

hard

A. Each new sensor can join without rewiring or central setup.

B. All sensors must connect directly to a central hub.

C. Sensors need to be manually configured with fixed routes.

D. Adding sensors requires shutting down the network temporarily.

Solution

1. Step 1: Understand mesh network scalability

   Mesh networks allow devices to join easily without complex setup or wiring.

2. Step 2: Apply to adding many sensors

   New sensors can join by connecting wirelessly and automatically finding routes, no central hub or shutdown needed.

3. Final Answer:

   Each new sensor can join without rewiring or central setup. -> Option A

4. Quick Check:

   Easy joining = mesh advantage [OK]

Hint: Mesh lets new devices join easily without rewiring [OK]

Common Mistakes:

• Thinking mesh needs central hub
• Assuming manual route setup is required
• Believing network must stop to add devices