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

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:

RFID for Livestock: Radio Frequency Identification (RFID) tags are the most widely used technology for livestock tracking and individual identification on large farms.

Benefits:

Unique ID: Each RFID tag has a unique code.

Data Storage: Some tags store information about the animal.

Durability: Tags withstand outdoor conditions.

Automated Reading: Tags can be scanned quickly.

References

RFID (General): https://en.wikipedia.org/wiki/Radio-frequency_identification

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.

IP Ratings & Manufacturing: IP66 provides:

Dust-tight: (First '6') Complete protection against dust ingress.

Powerful Water Jets: (Second '6') Protection against strong water jets from any direction.

Harsh Manufacturing Environments: IP66 is common due to dust, dirt, and potential exposure to liquids during cleaning or spills.

References

IP Ratings: https://en.wikipedia.org/wiki/IP_Code

Primary Concern: Safety: Building codes and safety regulations are there to prevent injury and accidents. This includes potential harm from improper equipment installation (falling objects, electrical hazards, etc.).

Legal and Ethical Responsibility: Organizations have an obligation to provide a safe workplace for employees and protect the well-being of end-users.

Insurance Considerations: While complying with codes may impact insurance rates, this shouldn't be the primary motivation, as safety itself is paramount.

Smart City Focus: Smart city initiatives mainly address infrastructure, environmental monitoring, and optimization of public services.

Ride-sharing Context: While self-driving technology could contribute to future smart city transportation, it's primarily a private-sector innovation, not a core municipal service like the other options.

Typical Smart City Applications:

Wi-Fi: Provides public internet access, enabling data collection

Pollution Monitoring: Tracks air/water quality for environmental management.

Demand-based Tolling: Adjusts pricing for traffic management.

XAML and .NET: XAML (eXtensible Application Markup Language) is primarily used within the .NET framework for defining user interfaces. Specifically, technologies like:

WPF (Windows Presentation Foundation): Desktop application UIs

Xamarin: Mobile app UIs

XAML in Other Frameworks: While some limited adaptation exists, its core use is tightly coupled with .NET technologies.

Legacy Support: The primary reason to continue using older wireless technologies is the need to connect with devices that don't support newer standards (e.g., old sensors or equipment).

Other Reasons (Not as Strong):

Cost: Replacing legacy devices can be expensive.

Reliability: Some legacy technologies might be well-proven in specific settings.

Smart Building Core Benefit: Smart building technologies primarily aim to optimize a building's operational efficiency through automation and data-driven insights.

Efficiency Examples:

Energy Management: Automated lighting and HVAC control based on occupancy and environmental conditions.

Maintenance: Predictive maintenance through IoT sensors reduces downtime.

Space Utilization: Optimization of space allocation based on real-time usage patterns.

References

Smart Buildings: https://en.wikipedia.org/wiki/Smart_building

Articles on Benefits of Smart Buildings: A quick search will yield many resources detailing these advantages.

Browser Ubiquity: JavaScript has a native runtime environment within almost every modern web browser, making it the 'built-in' scripting language for web-based interfaces.

Node-RED: This IoT flow-based programming tool specifically uses JavaScript for its logic and automation functions.

Other Languages:

PHP: Primarily server-side for web applications

Python: Versatile language, used in some back-end IoT functions but not natively in browsers

R: Statistical and data analysis, not typically embedded in wireless solutions

Coexistence Priority: Frequency coordination is the most critical aspect in ensuring that multiple wireless solutions function without significant interference.

Impact of Interference: Uncoordinated frequencies lead to:

Signal degradation: Reduced network performance and reliability.

Data errors and retransmissions: Inefficient operation and higher battery drain on devices.

QAM Constellations: QAM (Quadrature Amplitude Modulation) uses a constellation diagram where points represent unique combinations of amplitude and phase.

Bits per Symbol: The number in QAM-XX indicates the number of points:

QAM-16: 16 points = 2^4 = 4 bits per symbol

QAM-64: 64 points = 2^6 = 6 bits per symbol

Higher Data Rates: More points in the constellation enable transmitting more bits per symbol, leading to higher data rates at the same bandwidth.

References

QAM: https://en.wikipedia.org/wiki/Quadrature_amplitude_modulation

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.

Captive Portals for Guest Access: These are web pages that intercept users' requests before granting full internet access. They often require agreeing to terms, entering basic information, or viewing ads.

Hospitality Fit: Captive portals are simple to deploy, require minimal user setup, and provide control for the hospitality provider (e.g., usage limits).

Why Other Options Are Less Common:

NTLM: Microsoft authentication, mainly for corporate networks, too complex for casual guest use.

Kerberos: Complex authentication for enterprise, overkill for guest Wi-Fi

SIM Cards: Used in cellular devices, not for general Wi-Fi access.

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.

HTTP's Popularity: HTTP is the foundation of the web, making it widely known and supported. Developers have extensive familiarity with its concepts (methods, headers, status codes, etc.).

REST APIs and Webhooks: These often leverage HTTP for communication, building upon existing knowledge and tools.

Tradeoffs:

Security: HTTP itself is not inherently secure; HTTPS or additional layers address this.

Speed: Protocols optimized for IoT may have lower overhead, but HTTP's simplicity often outweighs minor performance differences.

IEEE 802.15.4: The IEEE 802.15.4 standard is a fundamental specification for low-rate wireless personal area networks (LR-WPANs). It serves as the basis for many wireless IoT protocols.

IEEE's Role: The Institute of Electrical and Electronics Engineers (IEEE) is the organization responsible for creating, maintaining, and publishing the 802.15.4 standard.

References

IEEE 802.15.4 Standard: https://standards.ieee.org/standard/802_15_4-2020.html

IEEE Website: https://www.ieee.org/