Spectrum Analysis Help regarding FFT Duty Cycle and SNR
Last Post: February 26, 2009:
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Ok, so recently I have done a site survey of the eastern half of our ware house, which is roughly around 250,000 sqf (almost 500,000 in total) . I want to try to utilize as much of the software that I have to generate reports or at least get a general idea of what I am looking at with our wireless network.
I am using Fluke Networks' InterpretAir for the survey, and AnalyzeAir for the spectrum analysis.
I have a few questions about SNR and FFT Duty cycle. If I am reading correctly, the information that the FFT Duty Cycle plot is showing me, it is the percentage of time that the signal is above the 20 dBm noise floor. Is 20 a default and rather generic level of SNR? The reason why I ask is because our network is running relatively smoothly, but the data I am seeing is contradicting that.
The only devices that access the wireless network are mounted MRX PCs on forklifts running simple telnet sessions to servers for inventory and warehouse management of products. We have a few hundred Intermec 2415 and Motorola MC3090s running the same simple telnet session for order picking and processing and of course the occasional laptop here in there when supervisors use the WLAN instead of the hard LAN.
Now, the main part of my question is what should I be seeing with the FFT Duty and SNR? The data I am seeing is showing that at any given point in time, in the area where i have the directional pointed, my signal is on average around 20% above the 20 dBm noise level.
This doesnt seem right to me at all. I look at the APs, and their retry errors are only a few, if any at all. Most of them are reporting 0, and some are reporting 2 or 3 with an uptime of 1 month (we do a monthly power cycle on our APs)
Do i need to edit the criteria for the reporting tool to see a more realistic report of our signals in the area?
Any ideas or better knowledge of running and viewing Spectrum Analyzers would be awesome!
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