Doodle Labs Smart Radio Посібник з усунення несправностей - Сторінка 9
Переглянути онлайн або завантажити pdf Посібник з усунення несправностей для Мережеве обладнання Doodle Labs Smart Radio. Doodle Labs Smart Radio 16 сторінок. Advanced mimo mesh router for resilient private wireless networks
Друкувати сторінкуSmart Radio Trouble-Shooting
Guide
Fresnel Zone Clearance
The required Fresnel Zone clearance is the radius around the line-of-sight path which must be
clear of obstancles. The Fresnel Zone clearance is frequency dependent, so we recommend
using an RF calculator to calculate the required clearance for your application. Drone
applications typically do not need to worry about Fresnel Zone clearance, but it is critical for
unmanned ground vehicles (UGV).
Noise and Interference
Background noise and interference has a direct effect on the achievable range. The 2.4-GHz ISM
band may be the most crowded frequency band in the world due to the ubiquity of 2.4-GHz
WiFi. Therefore, the achievable range in urbanized areas is notably poorer for the 2.4-GHz band
than other bands. Aside from the 2.4-GHz band, the 915-MHz band and the 5-GHz bands are
also license-free and may be highly congested depending on where the radios are being
deployed. You can measure the level of the background noise picked up by the radio using the
built-in spectrum analyzer on the wireless configuration page. This is only accessible in the
Advanced Settings. The figure below shows the wireless page with Advanced Settings enabled,
and a Spectrum Scan button available for the radio0 interface. The spectrum scanner is only
available for 10 MHz channel bandwidth or greater.
If you perform a spectrum scan, the radio will scan all channels. We recommend narrowing in
on the desired operating channel to check the noise performance as it will be faster and more
accurate. Note that the thermal noise floor is approximately -116 dBm per FFT bin in a 20-MHz
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Fig. 2 – Wireless page with Spectrum Scan available
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September 8, 2021