How do I read signal and noise ratings?

These numbers are actually in decibels or db and are expressed as negative numbers. So, a lesser number, like -10, represents more strength than -70.

Based on this Forum-postSignal -> Low is good (well -10 is good, -98 is bad, mathematically -10 is higher than -98.)

Noise -> High is good (-98 is good, -10 is bad, -70 would be pretty bad in the real world)

SNR -> High is good (should be the same as difference between noise and signal, a difference of 20 would be great, a difference of 1 may barely work)

Signal Quality -> High is good (somewhat like SNR but indexed to 100 with noise as the base, percentage of the best theoretical available quality in regards to your local-noise, difficult to explain *g*)

Examples would be:

    Signal  Noise  SNR  Signal Quality
   -82     -98    16   14%
    Signal - Noise = SNR
   -82    - -98   = 16
   Signal/Noise * SNR = Signal Quality
   -82   / -98  * 16  = 13.4%

Typically, noise will be -92 which means you should get a connection with a signal as low as -92. However, expecting to hold a good connection with a signal less than -85 (eg -90), is expecting too much. The signal can be improved by -3db by doubling the power setting at the transmitting radio, eg 100mW increased to 200mW would better your Signal from -85 to -82. Antennas with increased gain will also help. Say you had the standard 3db antenna and changed it for a 12db antenna, thats a 9 db increase, so your signal would increase from -82 to -73 which would be an excellent signal, probably capable of 54Mbps. Using the term excellent in terms of running a WISP, it would probably be only 3 bars on a 5 bar signal strength meter. Don’t worry if, as a WISP your Signal Quality is low, like 14%. It’s not really a problem since -82 is considered acceptable.

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