Menu

FAQ and other Resources

1) Where did wireless field science get its start? (however if you have an earlier citation, let us know!)

The first remote wireless sensing application for science for which the authors have been able to find information were unmanned weather stations, deployed in the Pacific in the 1940s (Wood, Louvan E. 1946. “Automatic Weather Stations.” Journal of Atmospheric Sciences 3 (December): 115–21.) These provided a variety of meteorological measures on a set schedule via automated pulses sent by scheduled shortwave radio broadcast. Data rates were on the order of a few bits/minute, and data reduction on the receiving end was conducted with a stopwatch (to count the number of pulses between delimiting signals) and a pad of paper/pencil.

 

 2) Some basics on the Radio Spectrum

Wireless communications operate in the electromagnetic spectrum - in the United States, this spectrum is managed by the Federal Communications Commission, who is responsible for promoting the economic uses of wireless communications and for preventing uses from interfering with each other. Access to the parts of the Radio Spectrum are provided via a wide set of mechanisms:

  • Licenses: users may be allowed to use spectrum in a particular frequency band for a specific time or in a specific place, typically with additional restrictions such as what they can broadcast or how much transmission power can be used.

    • Examples: Ham Radio operators, cellular providers, broadcast TV/radio stations, etc.

  • Fixed Allocations: Users may be given exclusive “rights holder” or priority access to parts of the electromagnetic spectrum by Congress or the FCC to perform particular functions.

    • Military use of radar frequencies, or police/fire for access to frequencies supporting civil needs

    • Commercial Radio Stations
    • Commercial Cellular Networks
  • White Space / Unlicensed

    • Frequency bands available for use by anyone, provided requirements for equipment certification and use are met to prevent signals from being transmitted outside of these bands

      • Wifi, Citizen’s Band Radio, Bluetooth, LoRA, etc

  • Dynamic Allocation: This is a new class of license in which users can employ spectrum owned by the US Department of Defense for civilian uses, provided their radios are enrolled in a “Spectrum Allocation System” which provides radios with time/geographically determined allocations via an online system.

    • CBRS (private 5G)

Here’s a simplified version of the radio spectrum useful for communications.  In general, high frequency wavelengths can provide greater data rates, but are useful at shorter distances due to interference with air, moisture, or terrain features (buildings, people, etc).