CWISA-102 Certified Wireless IoT Solutions Administrator Questions and Answers

• PtMP (Point-to-Multipoint): A single access point (AP) communicates with multiple client devices. This means the AP needs to manage how the available airtime is shared among those clients.
• Airtime Fairness: Mechanisms are needed to ensure that:
• PtP (Point-to-Point): A dedicated link only has two devices, eliminating the need for complex airtime management.
• Considerations in Both: While interference, SINR, and frequency selection are important in both PtMP and PtP systems, the need for airtime management is unique to the multipoint scenario.

References:

• Wireless Network Topologies (PtP vs. PtMP): Explanations of the differences in how communication is managed in each scenario.
• TDMA (Time Division Multiple Access): A common airtime sharing method used in PtMP systems.

• 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.

References:

• Identity and Access Management (IAM): Articles and resources outlining the core principles of authentication and authorization.
• Cybersecurity Best Practices: Guides on securing systems will often emphasize the need for both authentication and authorization controls.

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

References

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

• 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

• LoRa Modulation: LoRa (Long Range) is a proprietary wireless technology that utilizes Chirp Spread Spectrum (CSS) modulation.
• CSS Characteristics:

References

• LoRa: https://en.wikipedia.org/wiki/LoRa
• Chirp Spread Spectrum (CSS): https://en.wikipedia.org/wiki/Chirp_spread_spectrum

• 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:

• 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.

References:

• OSI Model: Descriptions of Network Layers, especially Layer 2 (Data Link) and Layer 3 (Network).
• Cloud Architecture: Diagrams showing how devices commonly access cloud resources through internet-based infrastructures.

• Free Space Path Loss (FSPL): Describes how a radio signal weakens as it travels through open space, even without obstacles. It's caused by the signal spreading out, resulting in decreased power density at the receiver.
• Calculation: FSPL depends on distance and frequency.

References

• Free Space Path Loss: https://en.wikipedia.org/wiki/Free-space_path_loss

• 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/

• 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.

• 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

• 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

• JSON Fundamentals: JSON (JavaScript Object Notation) is a text-based format for representing data in a structured, yet flexible way. Its key features are:
• JSON vs. Other Options

References:

• JSON Introduction: Clear definitions and examples of its syntax. (e.g., https://www.json.org/json-en.html)
• JSON Data Structures: Explanations of how arrays and nested objects are handled within JSON.

• 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:

References:

• Smart City Examples: Case studies showcasing common application areas (infrastructure, environment, utilities).
• Autonomous Vehicles and Smart Cities: Discussions of the potential interplay but emphasize the still-developing nature of self-driving tech.

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

• LoRa: This refers to the underlying radio modulation technique using Chirp Spread Spectrum (CSS). It defines how data is physically encoded onto the wireless signal.
• LoRaWAN: This is the network protocol built on top of LoRa. It manages device communication, network topology, and aspects like security. It operates at the MAC sublayer of the Data Link layer (Layer 2) of the OSI model
• LoRa vs. LoRaWAN: Key takeaway is that LoRa is the physical layer technology, while LoRaWAN adds the networking layer for management.

References:

• LoRa Modulation: Technical explanations of Chirp Spread Spectrum (CSS).
• LoRaWAN Specification: Official documentation detailing the network architecture and MAC layer functions.
• OSI Model: Descriptions of the Data Link layer and its role in networking.

• Lab Purpose: Wireless testing labs offer controlled settings to:
• Other Benefits (While not the primary benefit):

References

• Benefits of IT Labs: Can be extended from wireless to broader IT experimentation and learning. (Articles on this topic are readily available)