CWISE Practice Questions
Prepare for CWISE with more than an answer.
- Questions on the exam
- 5
- Level
- Expert
- Valid for
- 3 years
Domains covered on the exam 5
- Wireless IoT Administration (CWISA Foundation)20%
- Wireless IoT Connectivity (CWICP Focus)20%
- Wireless IoT Design (CWIDP Focus)20%
- Wireless IoT Integration (CWIIP Focus)20%
- Expert-Level Scenario Analysis20%
- 1
You are designing a LoRaWAN solution for a smart water metering project. The meters are located in deep basements. You calculate the Link Budget and determine you need a Maximum Coupling Loss (MCL) of at least 150 dB. Which Spreading Factor (SF) is most appropriate to ensure connectivity for these deep indoor devices?
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Correct answer: A
Higher Spreading Factors (SF) increase the range and sensitivity (link budget) at the cost of data rate and airtime. SF12 provides the highest sensitivity (typically around -137 dBm) and allows for MCL > 150 dB, making it suitable for deep indoor coverage. SF7 has the lowest range/sensitivity. SF9 is intermediate.
- 2
In a Zigbee network, which device type is responsible for starting the network, selecting the PAN ID, and holding the Trust Center functionality by default?
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Correct answer: D
The Zigbee Coordinator is the unique device that starts the network, selects the channel and PAN ID, and typically acts as the Trust Center for security key distribution. Routers extend the network but do not start it. End Devices are leaf nodes.
- 3
Case Study:
An agricultural company wants to monitor soil moisture across a 500-acre farm. The terrain is flat but has patches of dense vegetation.
Requirements:
- 500+ sensors.
- Data updates every 30 minutes.
- No mains power available in the field (solar/battery only).
- Central monitoring station is at the farmhouse on the edge of the property.
Constraints:
- Budget is limited.
- Cellular coverage is spotty.
Which technology provides the most viable solution?
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Correct answer: D
LoRaWAN is ideal for this scenario. It offers long-range coverage (miles/km) suitable for a 500-acre farm, operates on low power (battery/solar friendly), and handles low data rates (30 min updates) efficiently. A private network avoids recurring cellular costs and coverage issues. Wi-Fi has too short range and high power. Zigbee range is too short without many hops (routers need power). LTE-M depends on cellular coverage which is spotty.
- 4
What is the primary function of the 'Border Router' in a Thread network?
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Correct answer: D
A Thread Border Router connects the low-power 802.15.4 Thread mesh network to the adjacent IP network (like Wi-Fi or Ethernet), allowing IPv6 traffic to route between them. It does not translate protocols (like an application gateway) but routes IP packets.
- 5
Select THREE valid components of the Link Budget calculation. (Select THREE)
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Correct answer: A, B, D
Link budget includes Tx Power (source), Antenna Gains (amplification), and Losses (Cables, Free Space Path Loss). Data rate is a result/parameter, not a direct dB component in the sum (though it affects sensitivity).
- 6
A manufacturing plant is deploying a Wireless Sensor Network (WSN) to monitor vibration on rotating machinery in a highly metallic environment. The sensors are battery-powered and must operate for 5 years without maintenance. The environment has significant multipath propagation issues. Which modulation technique would provide the highest resilience against multipath fading while maintaining low power consumption for this specific environment?
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Correct answer: C
Chirp Spread Spectrum (CSS) uses wideband linear frequency modulated chirp pulses to encode information. This technique is inherently resistant to multipath fading and Doppler effect, making it ideal for harsh industrial environments with metallic obstructions. ASK is highly susceptible to noise and fading. OFDM is robust but typically requires higher power and processing overhead than CSS for simple sensor networks. FSK is robust but less resilient to severe multipath than CSS in this context.
- 7
Which organization is primarily responsible for developing the specifications for the Matter protocol, which aims to unify smart home IoT device interoperability?
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Correct answer: B
The Connectivity Standards Alliance (CSA), formerly the Zigbee Alliance, is the organization responsible for developing and maintaining the Matter specification. IEEE develops physical and MAC layer standards (like 802.15.4). IETF develops internet protocols (like 6LoWPAN). The Wi-Fi Alliance focuses on WLAN interoperability.
- 8
True or False: In a smart city deployment, the Noise Floor is a static value that can be measured once during the initial site survey and safely assumed to remain constant throughout the lifecycle of the IoT network.
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Correct answer: B
False. The noise floor is dynamic and changes based on environmental factors, new electronic device deployments, and other RF interference sources. In a smart city, the RF environment is particularly volatile due to the constant addition of new infrastructure and consumer devices. Continuous monitoring is required.
- 9
You are designing an IoT solution for a logistics company that requires tracking assets across a large warehouse (200,000 sq ft). The requirements state that assets must communicate directly with each other to update status ledgers without routing traffic through a central gateway for every transaction. Which network topology is best suited for this requirement?
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Correct answer: B
A Full Mesh topology allows every node to communicate directly with every other node (assuming they are within range), facilitating peer-to-peer communication without reliance on a central coordinator for local logic. A Star topology requires all traffic to pass through a central hub. A Cluster Tree is hierarchical and may not support arbitrary peer-to-peer without routing up the tree.
- 10
When implementing a WirelessHART network in a process control environment, you observe that the network reliability is suffering due to frequency-selective fading. Which feature of WirelessHART specifically addresses this issue by changing the transmission frequency for each packet?
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Correct answer: B
Time Slotted Channel Hopping (TSCH) is the MAC mechanism used by WirelessHART (and ISA100.11a). It combines Time Division Multiple Access (TDMA) with channel hopping. For every timeslot, a different frequency channel is used based on a hopping sequence, effectively mitigating frequency-selective fading and persistent interference on any single channel.
