Free CWISA-103 sample questions

Correct answer: False

False. While operating multiple radios simultaneously can increase instantaneous power draw, MLO can significantly reduce overall energy consumption for battery-powered IoT devices. By aggregating links, the device can transmit its data much faster and return to a low-power sleep state more quickly. This reduction in active time often outweighs the higher instantaneous power draw, leading to net power savings over time.

Correct answer: Implement a Bluetooth Low Energy (BLE) based RTLS using battery-powered BLE asset tags. The existing Wi-Fi 6E APs, which have integrated BLE radios, will listen for tag advertisements and forward the data to a central location engine.

This solution meets all requirements. BLE tags provide multi-year battery life. Leveraging the integrated BLE radios in the existing Wi-Fi 6E APs requires no new cabling. The APs act as gateways, collecting BLE data without the tags needing to connect to the secure Wi-Fi network, thus bypassing WPA3-Enterprise complexities for the tags themselves. RSSI-based locationing from a dense AP deployment can achieve the required room-level accuracy. The data can then be sent over the existing network to the management platform.

Correct answer: 24 dBm

The calculation is as follows: 1. Convert transmitter power to dBm: 100 mW = 20 dBm (since 10 * log10(100) = 20). 2. Calculate total cable loss: 10 meters * 0.5 dB/meter = 5 dB. 3. Calculate EIRP: EIRP (dBm) = Tx Power (dBm) - Cable Loss (dB) + Antenna Gain (dBi). 4. EIRP = 20 dBm - 5 dB + 9 dBi = 24 dBm.

Correct answer: A faulty microwave oven operating near the Zigbee coordinator.

Microwave ovens are a notorious source of wideband RF interference in the 2.4 GHz band. A faulty or poorly shielded oven can raise the noise floor across the entire band, affecting all Zigbee channels, as well as Wi-Fi and Bluetooth. Wi-Fi interference would typically appear as a distinct 20 or 40 MHz wide signal, not a consistently high noise floor across all channels.

Correct answer: RPL (Routing Protocol for Low-Power and Lossy Networks)

RPL is the standard routing protocol for 6LoWPAN and was designed by the IETF specifically for the constraints of Low-Power and Lossy Networks (LLNs). It builds a Destination Oriented Directed Acyclic Graph (DODAG) and has modes of operation (storing and non-storing) that allow it to efficiently manage routes for sleepy end devices, minimizing the communication required and thus conserving battery life.

Correct answer: LoRaWAN

LoRaWAN is a Low Power Wide Area Network (LPWAN) technology specifically designed for long-range (kilometers), low-power communication. Its use of Chirp Spread Spectrum (CSS) modulation provides excellent resilience to interference and deep indoor penetration, making it ideal for sending small, infrequent data packets in challenging urban environments.

Correct answer: An attacker can passively decrypt all network traffic, potentially exposing sensitive operational data.

The Zigbee network key is used to encrypt the network layer and application layer data frames. If an attacker knows this key, they can use a Zigbee sniffer to capture and decrypt all traffic on the network. This allows them to not only view sensitive data but also to analyze traffic patterns to plan more sophisticated attacks, such as injecting malicious commands.

Correct answer: To receive messages from publishers and filter and forward them to subscribed clients.

The MQTT Broker is the central hub in a publish/subscribe messaging system. Its core responsibility is to manage the flow of messages. It receives messages published by clients (like sensors) on specific 'topics' and then forwards those messages only to clients that have subscribed to those topics. This decouples the message producers from the consumers.

Correct answer: A system using antenna diversity

Antenna diversity uses two or more antennas to combat the effects of multipath fading. The receiver can switch to or combine signals from the antenna that is experiencing the best signal conditions at any given moment. This spatial diversity provides a more robust and reliable link in environments with high levels of reflection and signal cancellation.

Correct answers: Access to a large amount of contiguous, greenfield spectrum, reducing interference.; Mandatory use of WPA3 security, enhancing network protection.; Support for more non-overlapping channels, allowing for denser AP deployments without co-channel interference.

Wi-Fi 6E operates in the 6 GHz band, which provides up to 1,200 MHz of new spectrum. This band is free from interference from legacy Wi-Fi devices, microwave ovens, and Bluetooth, leading to a much cleaner RF environment and more reliable performance.

The Wi-Fi Alliance requires that all devices operating in the 6 GHz band use WPA3 security. This eliminates outdated, less secure protocols like WPA2-PSK (TKIP) and WEP, ensuring a higher baseline of security for all connections.

The vast amount of new spectrum in the 6 GHz band allows for a significant number of non-overlapping channels (e.g., up to 59 20-MHz channels). This makes channel planning much simpler and enables very dense deployments of access points without them interfering with each other, which is ideal for a university campus.