Wireless Communication Basics
Which describes Bluetooth Low Energy (BLE)?
- AIt uses sub-GHz bands such as the 920 MHz band and can communicate with devices several kilometers or more away where line of sight is clear
- BIt uses the 2.4 GHz band and keeps power consumption low by communicating only briefly and resting the rest of the time, and is used in wearables, sensors and similar devices
- CIt uses 13.56 MHz electromagnetic induction to communicate between devices brought within a few centimeters of each other
Show answer and explanation
Answer: B. It uses the 2.4 GHz band and keeps power consumption low by communicating only briefly and resting the rest of the time, and is used in wearables, sensors and similar devices
BLE is a short-range wireless standard in the 2.4 GHz band that keeps communication time very short and shuts down circuits the rest of the time, so devices can run a long time even on coin cells. Without connecting, a device can periodically send short signals called advertisements to announce its presence or small amounts of data to its surroundings, which is used for beacons. It uses the same 2.4 GHz band as classic Bluetooth (BR/EDR), but the communication methods differ, so the two cannot talk to each other directly (some devices support both).
- A. These are characteristics of LPWA (such as LoRaWAN).
- B. Correct. It saves power by communicating briefly and then resting.
- C. These are characteristics of NFC.