Wireless Technology Flashcards

Which wireless protocol operates in the 900 MHz band and is commonly used for long-range IoT sensor networks?

Answer: LoRaWAN

LoRaWAN uses 915 MHz (in the US) and is designed for low-power, long-range IoT applications spanning many miles.

In 802.11 networks, what is the purpose of the RTS/CTS mechanism?

Answer: To reserve the wireless medium before transmitting large frames, reducing collisions

RTS/CTS (Request to Send/Clear to Send) is a collision avoidance mechanism that reserves the channel before large frame transmissions.

What is the typical frequency range of Bluetooth Classic technology?

Answer: 2.400 GHz – 2.4835 GHz

Bluetooth Classic and Bluetooth Low Energy (BLE) both operate in the 2.4 GHz ISM band from 2.400 to 2.4835 GHz.

A VDV technician needs to connect a building's access points back to a central switch without running cables through the ceiling. Which technology is most appropriate?

Answer: Wireless mesh networking

Wireless mesh networking allows APs to backhaul traffic wirelessly to each other and ultimately to a wired uplink point.

What is the maximum transmission power typically allowed for 2.4 GHz Wi-Fi in the United States per FCC Part 15 rules?

Answer: 100 mW (20 dBm)

FCC Part 15 limits 2.4 GHz WLAN transmitter output to 1 W (30 dBm), but with antenna gain the EIRP is limited to 4 W; typical device limits are 100 mW (20 dBm).

Which wireless technology uses frequency hopping spread spectrum (FHSS) to avoid interference?

Answer: Bluetooth Classic

Bluetooth Classic uses FHSS, rapidly hopping between 79 channels in the 2.4 GHz band 1,600 times per second.

When performing a passive wireless site survey, the technician walks through the facility without doing what?

Answer: Associating with the wireless network or generating traffic

A passive survey measures existing RF conditions by listening only, without connecting to or generating traffic on the network.