CWISA-102 Certified Wireless Iot Solutions Administrator Practice Questions

A BLE-based RTLS meets all the specified requirements. BLE tags are low-cost and have excellent battery life. Deploying a dedicated network of BLE anchors avoids interfering with the congested Wi-Fi network. BLE RTLS, especially with Angle of Arrival (AoA) or RSSI-based trilateration, can easily achieve the required 5-10 meter accuracy. Modern RTLS platforms natively support geofencing. GPS would not work indoors, and active RFID may be more expensive and offer less sophisticated location capabilities.

The formula for converting milliwatts (mW) to dBm is: 10 * log10(Power in mW). Therefore, 10 * log10(100) = 10 * 2 = 20 dBm. A wireless professional should also know common conversions: 1 mW = 0 dBm, 10 mW = 10 dBm, 100 mW = 20 dBm, 1000 mW (1W) = 30 dBm.

This is false and represents a major security risk. Medical IoT devices should be placed on a separate, secured, and isolated network segment (e.g., a dedicated VLAN and SSID) with strict access controls. Connecting critical devices to an untrusted network like a guest network would expose them to potential attacks and violate regulatory compliance standards like HIPAA.

Polarization diversity uses two antennas with different polarizations (e.g., vertical and horizontal, or two slanted at +/- 45 degrees). When an RF signal reflects, its polarization can change. A diversity antenna system can select the antenna receiving the strongest signal at any given moment, effectively mitigating the nulls caused by multipath fading. This is a common technique in challenging RF environments.

Diffraction is the phenomenon where RF waves bend around the edges of an obstacle they encounter. This behavior is what allows for non-line-of-sight (NLOS) communication, as signals can reach receivers even when the direct path is blocked. Reflection is when waves bounce off a surface, refraction is when they bend passing through a medium, and scattering is when they are reflected in many directions by a rough surface.

A Wireless Body Area Network (WBAN), standardized under IEEE 802.15.6, is specifically designed for short-range, low-power wireless communication in, on, or around the human body. This makes it the ideal choice for medical applications like real-time patient monitoring. WPANs (like Bluetooth) cover a slightly larger area (a room), while WLANs and WSNs are designed for different scopes and purposes.

EIRP is calculated by taking the transmitter's power, adding the antenna gain, and subtracting any losses before the antenna (like cable loss). The formula is: EIRP = Transmitter Power (dBm) - Cable Loss (dB) + Antenna Gain (dBi). In this case: 20 dBm - 2 dB + 12 dBi = 30 dBm. The receive-side values are not needed to calculate the transmit EIRP.

LoRaWAN is specifically designed for long-range (kilometers), low-power, low-data-rate applications, making it ideal for this scenario. Its excellent link budget allows gateways on silos to cover vast areas, and its low power consumption enables multi-year battery life. The ability to deploy a private network is also a key advantage where no public coverage exists. Bluetooth Mesh and Wi-Fi HaLow have insufficient range, and NB-IoT requires cellular coverage.

Transport Layer Security (TLS) is the standard cryptographic protocol used to provide end-to-end security for data in transit over a network. It is used to secure protocols like HTTPS and MQTTS (MQTT over TLS). TCP provides reliable delivery but no encryption. SSH is for secure remote administration, not typically for encapsulating application data streams. SNMP is a network management protocol.

In the 2.4 GHz band, Wi-Fi channel 6 (2.437 GHz center) significantly overlaps with Zigbee channel 15 (2.425 GHz center). Heavy Wi-Fi traffic can raise the noise floor and interfere with Zigbee communications, causing packet loss and unresponsiveness, especially for devices at the edge of the mesh with weaker signals. The best practice is to move the Zigbee network to a non-overlapping channel like 25 or 26.