CWISA-102 Sample Questions Answers

• Attenuation: Describes the progressive loss of signal strength as it travels through a medium (like air, cables, walls). It's caused by factors like absorption, distance, and obstacles.
• Other Phenomena:

References

• Attenuation: https://en.wikipedia.org/wiki/Attenuation

• IP Ratings & Manufacturing: IP66 provides:
• 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

• XAML and .NET: XAML (eXtensible Application Markup Language) is primarily used within the .NET framework for defining user interfaces. Specifically, technologies like:
• XAML in Other Frameworks: While some limited adaptation exists, its core use is tightly coupled with .NET technologies.

References:

• XAML Overview (Microsoft Docs): Introductions to XAML emphasizing its use in .NET applications.
• WPF Documentation: Tutorials and references specifically mentioning XAML's role in Windows desktop development.

• 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.

References:

• Service Level Agreements (SLAs): Documentation related to outsourced work may be defined as a deliverable within an SLA.
• Knowledge Management Best Practices:

• 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:

References:

• Captive Portals: Explanations of how they work and their use cases.
• Guest Wi-Fi in Hospitality: Best practices highlight the prevalence of captive portals in this industry.

• OFDM vs. OFDMA:

References

• OFDM: https://en.wikipedia.org/wiki/Orthogonal_frequency-division_multiplexing
• OFDMA: https://en.wikipedia.org/wiki/Orthogonal_frequency-division_multiple_access

• IETF's Focus: The Internet Engineering Task Force (IETF) primarily develops and standardizes internet protocols operating at the Network Layer (Layer 3) and above in the OSI model.
• Key Protocols: Some prominent IETF-developed protocols include:

References

• IETF Website: https://www.ietf.org/
• OSI Model: https://en.wikipedia.org/wiki/OSI_model

• KPI alignment: Key Performance Indicators (KPIs) define success metrics for the wireless IoT solution (e.g., uptime, device responsiveness, data accuracy). Continuous monitoring tracks performance against these KPIs.
• Meeting Business Needs: Monitoring ensures the solution delivers the intended value. Are response times fast enough? Are business processes supported effectively?
• Proactive maintenance: Monitoring can reveal performance issues before they become critical failures, allowing for proactive fixes.
• Optimization: Monitoring data over time helps identify areas for fine-tuning the solution to further align with business requirements.

References

• Wireless IoT monitoring tools: Vendor documentation or articles on specific tools and the KPIs they can track.
• ITIL (Information Technology Infrastructure Library): Frameworks emphasizing monitoring and continuous improvement.

• 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/

• Wireless Transceiver: A transceiver is a combination of a transmitter and receiver used for wireless communication.
• Radio: The radio is the primary component responsible for:

References

• Transceiver: https://en.wikipedia.org/wiki/Transceiver

• SBCs (Single Board Computers): Designed as standalone, small-form-factor computers. They often include:
• Controller Boards: Focus on controlling specific hardware or systems.

References

• SBC Examples: https://www.raspberrypi.org/, https://www.beagleboard.org/
• Controller Board Examples: https://www.arduino.cc/

• Signal Strength and Data Rate: In wireless links, weaker signal strength often directly correlates to reduced transmission speeds. Modern wireless technologies use adaptive modulation and coding, sacrificing speed for reliability when signals become weaker.
• Noise and Interference: While these can impact performance, they don't inherently decrease simply because signal strength drops.
• Latency: Latency can be affected by poor signal, but its primary drivers are distance and network congestion.

References:

• Wireless Signal Strength vs. Speed: Articles explaining the relationship and how adaptive modulation works.
• Modulation and Coding Schemes (MCS): Technical descriptions of how Wi-Fi and other wireless technologies adjust speeds based on signal quality.

• Customization and Integrations: The presence of APIs often suggests a system is integrated with other platforms or has custom-built elements.
• Understanding Dependencies: Documenting used APIs helps clarify how different parts of the system interact and where potential issues might arise.
• Troubleshooting Efficiency: Detailed API documentation aids in resolving problems, allowing staff to assess interconnected systems effectively.
• Knowledge transfer: Future support teams won't have to reverse-engineer the system; documentation ensures smooth handover and understanding.

References:

• Best practices API documentation: Guides on API documentation formats and the level of detail needed for maintenance. [Example: Swagger, OpenAPI Specification] (https://swagger.io/)
• Software Development Life Cycle (SDLC): Materials emphasizing the importance of documentation during development and support phases.

• 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.

References:

• Occupational Safety and Health (e.g., OSHA in the US): Websites of regulatory bodies outlining guidelines for safe equipment installation in various settings.
• Electrical Codes (e.g., National Electrical Code): Standards that address safe practices to prevent fire and shock hazards.

• Overlay vs. Integrated Monitoring:
• Overlay Advantage: Since the overlay system is separate, it doesn't add overhead or complexity to the core network, avoiding potential disruption of wireless services.

• WBAN Range: Wireless Body Area Networks (WBANs) specialize in short-range communication around the human body. Typical ranges fall within 1-2 meters.
• Purpose: This range is designed to:

References

• WBAN Overview: https://en.wikipedia.org/wiki/Body_area_network
• WBAN Research Paper (Check Range Discussion): https://www.mdpi.com/2224-2708/11/4/67

• Requirements Drive Decisions: The decision between wired or wireless must align with the solution's overall purpose, performance targets, and operational constraints.
• Key Considerations:
• Other Factors are Important, But Secondary: Distance, PoE availability, specific applications all matter, but they are assessed within the context of the overarching business needs.

References:

• Wireless vs. Wired Network Design: Comparisons of pros and cons, highlighting how use cases guide the choice.
• IoT Solution Planning: Materials on defining requirements before selecting technology.