CWISA-103 Certified Wireless IoT Solutions Administrator(2025 Edition) Questions and Answers

Importance of Time Sync in IoT: Coordinated actions, accurate data analysis, and event logging in wireless IoT solutions often rely on devices having a shared time reference.

NTP's Role: Network Time Protocol (NTP) enables devices to synchronize their clocks against a reliable time source (NTP server), ensuring consistency across the network.

Why Other Options Don't Fit:

IP Addressing: Usually handled by DHCP, not NTP.

Encryption: SSL/TLS secure data in transit, not related to timekeeping.

Name Resolution: Purpose of DNS, not NTP.

Health IoT Device Categories:

Wearable: Devices worn on the body (smartwatches, fitness trackers).

Non-wearable: Devices used without being worn (smart scales, connected medical equipment).

Implantable: Surgically inserted devices (pacemakers, glucose monitors).

References

Health IoT: Resources on healthcare + IoT will illustrate device types.

Authentication: Verifying "who" the user or device is (e.g., via passwords, certificates).

Authorization: Controlling "what" a user or device can do once authenticated (e.g., read-only vs. read/write permissions).

Combined for Security: Both are essential. Authentication alone doesn't control access levels, and authorization without verification is meaningless.

Cloud Connectivity Relies on IP: Most cloud-based services operate via the internet, which utilizes Internet Protocol (IP) at Layer 3 of the network model.

Flexibility: Various Layer 2 technologies (Ethernet, Wi-Fi) can connect to a Layer 3 network that ultimately provides Internet access

BLE Exception: Bluetooth Low Energy can have cloud connectivity, but often through gateways and not as a direct Layer 2 connection.

Eliminating Incorrect Options: IPX/SPX is an outdated protocol, and cellular is only one possible way to achieve Internet access.

SBCs (Single Board Computers): Designed as standalone, small-form-factor computers. They often include:

Display Interfaces: HDMI, DisplayPort, etc.

Input Connections: USB for keyboards, mice, etc.

General Purpose Functionality: Can run a full operating system for wider applications.

Controller Boards: Focus on controlling specific hardware or systems.

Limited direct I/O: Limited connectors for displays/input devices.

Specialized tasks: Designed for embedded applications within larger systems.

References

SBC Examples: https://www.raspberrypi.org/ , https://www.beagleboard.org/

Controller Board Examples: https://www.arduino.cc/

Outsourcing Knowledge Transfer: When outsourcing implementation, the service provider has firsthand knowledge of system setup and configuration. Clear documentation ensures this knowledge remains accessible to you after the project is complete.

Ongoing Support: While paid/free support options influence long-term maintenance, they won't substitute missing documentation about the specific setup.

Reducing Future Vendor Reliance: Detailed documentation helps mitigate over-reliance on the service provider for minor changes and troubleshooting, giving you more long-term autonomy.

Proof of Concept: A POC typically happens before outsourcing, and focuses on validating the solution's feasibility, not ensuring smooth knowledge transfer thereafter.

PoE Splitter: A PoE splitter separates power and data from a PoE-enabled Ethernet cable, allowing the powering of non-PoE devices.

Other PoE Devices:

PoE Injector: Adds power to non-PoE Ethernet cable.

PoE Switch: Provides power directly through its ports.

60GHz Absorption: The 60GHz band experiences significant signal attenuation due to absorption by oxygen molecules in the atmosphere. This severely restricts the usable range of wireless systems operating in this frequency.

Why Other Options Don't Apply:

Atmospheric Scattering: Impacts longer wavelength transmissions, less significant at 60GHz.

Solar Radiation: Can cause interference on some frequencies, but not a primary range limitation at 60GHz.

Rain Fade: Primarily affects higher frequencies (above 10GHz), but its impact is less severe than oxygen absorption at 60GHz.

BLE Beacon Power Efficiency: Bluetooth Low Energy (BLE) beacons are designed for low power consumption. Their primary function is to periodically broadcast short data packets (advertising their presence).

Other Technologies:

Cellular: More power-hungry due to long-range communication and complex protocols.

GPS: Power intensive, especially when actively tracking location.

Wi-Fi:

Key Modulation Differences:

ASK (Amplitude Shift Keying): Digital data is represented by changes in the amplitude (strength) of a carrier wave.

FSK (Frequency Shift Keying): Digital data is represented by changes in the frequency of a carrier wave.

References

ASK: https://en.wikipedia.org/wiki/Amplitude-shift_keying

FSK: https://en.wikipedia.org/wiki/Frequency-shift_keying

SSL/TLS Secures Web Traffic: HTTPS builds upon HTTP, adding the encryption provided by Secure Sockets Layer (SSL) or its successor, Transport Layer Security (TLS).

Other Protocols Have Different Purposes:

IPSec: Secures IP traffic at a network level, can be used alongside TLS.

SNMPv3: Management protocol, offers security features, but not the primary mechanism in HTTPS.

SSH: Secure remote shell, unrelated to web data encryption.

Perception Layer: The foundation of an IoT system, it consists of sensors and actuators that:

Sense: Collect data about the environment or object being monitored.

Actuate: Potentially make changes based on commands (e.g., a smart valve opening/closing).

Transmit: Send gathered data to upper layers for processing.

WWAN (Wide-Area Wireless Network): WWANs provide connectivity over extensive geographic areas, typically covering regions or even entire countries.

Cellular Technology: WWANs often rely on cellular networks (3G, 4G, 5G) offered by mobile carriers.

References

WWAN: https://en.wikipedia.org/wiki/Wireless_wide_area_network

IIoT Environments: Industrial IoT (IIoT) often involves deployment in harsh environments (factories, plants, outdoor sites) with:

Extreme temperatures

Dust & Vibrations

Exposure to chemicals or moisture

Ruggedization: IIoT devices are designed to withstand these conditions, ensuring reliability and longevity.

References

IIoT: https://en.wikipedia.org/wiki/Industrial_Internet_of_things

Rugged Devices: Articles on ruggedized electronics will emphasize their importance in industrial settings.

Mesh Connectivity Depends on Signal: Mesh nodes relay data for each other. Weak signal strength between nodes can disrupt connectivity throughout the network.

Troubleshooting Signal Issues: Physically relocating affected nodes can improve their ability to form stable connections with other nodes in the mesh.

Why Other Options May Not Help:

Separate Mesh: Splits the network, not solving the root connectivity issue

Output Power: May help marginally, but significant improvement is typically achieved through repositioning.

Security Settings: Unlikely to cause connectivity issues between properly configured nodes in the same mesh.

SINR vs. SNR:

SNR (Signal-to-Noise Ratio): Measures the power of the desired signal relative to background noise.

SINR (Signal-to-Interference-plus-Noise Ratio): Considers both background noise and interference from other signals operating on the same frequency.

Practical Importance: SINR is a more realistic indicator of real-world signal quality in wireless environments where interference is a significant factor.

References

SINR: https://en.wikipedia.org/wiki/Signal-to-interference-plus-noise_ratio

SNR: https://en.wikipedia.org/wiki/Signal-to-noise_ratio

Capacity Planning: The number of devices a wireless network can support is the primary determinant of its required capacity. This is because:

Traffic Load: Each device generates network traffic that contributes to the overall load.

Resource Sharing: Devices compete for airtime and bandwidth resources.

Device Type: Requirements vary; a simple sensor has different needs than a video camera.