From St. Louis Hackerspace Wiki
This page includes results from a brief survey performed of the Wifi spectrum on 3-9-2010 in the Lemp Brewery space, for your amusement. The equipment used was a Ubiquiti AirView USB spectru analyzer, a 5dB dipole, and a wee little ASUS EeePC netbook.
Here is the initial SpecAn display. []
Here is the display after a 15minutes. []
Here is the display after running for approximately one hour. []
If these are too boring, here is an animated PNG (1.3MB) of 5 consecutive screen caps of the SpecAn results, taken over the course of ~1hour. You will notice the line of noise that appears in the top panel gradually progressing upward, i.e. back in time. []
Here is an alternate display, showing channel usage. []
To accompany the analyzer results given above, here is what iwlist had to say about the AR space:
Cell 01 - Address: 00:21:29:80:FC:02 Channel:6 Frequency:2.437 GHz (Channel 6) Quality=39/70 Signal level=-71 dBm Encryption key:on ESSID:"archreactor" Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s 24 Mb/s; 36 Mb/s; 54 Mb/s Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 48 Mb/s Mode:Master Extra:tsf=0000008e5a45e183 Extra: Last beacon: 404ms ago IE: Unknown: 000B6172636872656163746F72 IE: Unknown: 010882848B962430486C IE: Unknown: 030106 IE: Unknown: 2A0104 IE: Unknown: 2F0104 IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : CCMP Pairwise Ciphers (1) : CCMP Authentication Suites (1) : PSK IE: Unknown: 32040C121860 IE: Unknown: 2D1A1C181AFFFF000000000000000000000000000000000000000000 IE: Unknown: 3D1606001F00000000000000000000000000000000000000 IE: Unknown: 7F0101 IE: Unknown: DD090010180209F0010000 IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00 IE: Unknown: DD1E00904C331C181AFFFF000000000000000000000000000000000000000000 IE: Unknown: DD1A00904C3406001F00000000000000000000000000000000000000 Cell 02 - Address: 00:1E:2A:55:28:6C Channel:1 Frequency:2.412 GHz (Channel 1) Quality=40/70 Signal level=-70 dBm Encryption key:on ESSID:"SKool HOuse 1" Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 6 Mb/s; 9 Mb/s 11 Mb/s; 12 Mb/s; 18 Mb/s Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s Mode:Master Extra:tsf=000000162fffb181 Extra: Last beacon: 856ms ago IE: Unknown: 000D534B6F6F6C20484F7573652031 IE: Unknown: 010882848B0C12961824 IE: Unknown: 030101 IE: Unknown: 0706555320010B1B IE: Unknown: 200100 IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK IE: WPA Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK IE: Unknown: 2A0102 IE: Unknown: 32043048606C IE: Unknown: DD180050F2020101060003A4000027A4000042435E0062322F00 IE: Unknown: DD0900037F0101002EFF7F IE: Unknown: DD1A00037F0301000000001E2A55286C061E2A55286C64002C012E08
Pretty boring here, nothing salacious to report. The 2 active access points on channels 1 and 6 appear quite clearly, with their sidebands quite clear of overlap. There is definitely a very narrow-band trace that appears near channel 11 which is likely not a Wifi device. Access points set to this channel may have difficulties.
Of interesting note is the horizontal band that appears in the top panel of the SpecAc display (the "Waterfall" panel), and which gradually drifts upward in the animation. This recorded the moment when I carried the SpecAc over to the three, powered laptop guts that hang on the wall next to the entry door. So, if ever you were curious why laptop cases are shielded...