What frequencies and modulation techniques does LoRa use?
What will be an ideal response?
LoRa networks operate at lower, usually license-exempt, frequencies. In North America, LoRa transmits in the 902 to 928 MHz ISM band using sixty-four 200 KHz downlink channels and eight 500 KHz uplink channels, plus an additional eight 500 KHz downlink channels. In Europe LoRa uses the 867 to 869 MHz band with a total of 10 channels. The LoRa specification covers OSI Layer 1 only and currently specifies the use of chirp spread spectrum (CSS) modulation, which has been used in military applications for several decades, because CSS supports long-range communications, as well as being resistant to interference and to multipath distortion.
You might also like to view...
Which of the following would not be considered normal during the heating mode of a heat pump?
a. Hot, high-pressure refrigerant flows through the indoor coil. b. The outdoor check valve is pushed open. c. The refrigerant flows through the outdoor TXV. d. The reversing valve is de-energized.
____ is used to describe things that result from human activity
A) Anthropogenic B) Antiplasmatic C) ?Anthropomorphism D) Antebellum
Which of the following measures is the standard airflow across an air-conditioning coil?
A) 400 CFM per ton B) 600 CFM per ton C) 500 CFM per ton D) 300 CFM per ton
For the electromagnet of Figure P18.1:
a. Find the flux density in the core.
b. Sketch the magnetic flux lines and indicate their direction. c. Indicate the north and south poles of the magnet.
