3 ms·

Microwave seems promising.

• ac29 10y ago
  Microwave, as a radio term, isn't very useful. It covers 300 MHz to 30 GHz [0], which is nearly the entire usable radio spectrum. In industry terminology, microwave generally refers to >GHz radios, which have real problems in terms of obstacle penetration and range. In the >GHz range, you more or less require line of sight for transmissions over a kilometer or so, which often isnt practical. Free space path loss [1] is also an issue on long links, as signal loss is proportional to the square of frequency. A good practical example is to compare 2.4GHz WiFi to 5GHz WiFi. At the same power level (both are restricted to 1W in the US for unlicensed operation), 2.4GHz will cover approximately four times the distance ~(5/2.4)^2. However, much more spectrum is available in the 5GHz range, and signals cant travel as far which leads to less interference given an equal number of transmitters. Those factors give higher throughput, but free space path loss constrains coverage on 5 vs 2.4 GHz WiFi. Another example would be cellular: low frequency towers are used to expand coverage and improve building penetration, high density high frequency towers are used to improve speeds. Feel free to email me at my profile address -- I work in the sub-GHz narrowband radio industry. [0] https://en.wikipedia.org/wiki/Microwave https://en.wikipedia.org/wiki/Microwave [1] https://en.wikipedia.org/wiki/Free-space_path_loss https://en.wikipedia.org/wiki/Free-space_path_loss
  • Aelinsaar 10y ago
    I'm talking about site to site.