Grid ofAccess Points
This grid of local access points is updated in (semi) realtime -- that is, scans are performed approximately once every 5 seconds. The data for each column is briefly described below:
SSID |
Service Set Identifier -- a human-readable identifier corresponding to a wireless network. In general, there could be multiple BSSIDs (i.e. APs) operating on the same wireless network and using the same SSID. A client station (STA) can choose to associate with any of the BSSIDs on the same wireless network (though performance may differ for a variety of reasons). |
BSSID (MAC) |
Basic Service Set Identifiers -- corresponds to the access points (APs) from whom beacons were detected. For infrastructure 802.11 networks, the BSSID is equivalent to the MAC address of the AP. |
Channel |
An access point is configured to transmit/receive on a particular 802.11 channel (actually, a specific frequency range). Under 802.11 b/g there are 14 possible channels, but only 11 are used in North America (i.e. channels 1 - 11). |
Beacon Strength (dBm) |
Received signal strength indication (RSSI) in dBm. This measures the strength or power of the "I'm here" beacon transmitted from an AP approximately every 100 mSec. It is a reflection of the distance between the AP and the client STA and is *not* an indication of performance. |
Beacon Strength (mWatt x 10^6) |
Same as above, but measured in mWatt x 10^6. |
Beacon Quality (%) |
Converts the beacon's signal level into a signal quality (0-100%) -- where a maximum signal is assumed to be -20 dBm and the dissociation signal is -85 dBm (http://www.ces.clemson.edu/linux/dbm-rssi.shtml). More intuitive than reporting a RSSI in dBm or mWatt. |
Beacon Quality |
Qualitative measure of beacon strengths: where "Excellent" implies > -57 dBm, "Very Good" implies > -67 dBm, "Good" implies > -71 dBm, "Low" implies > -81 dBm, and "Very Low" implies > -90 dBm. Any RSSI below -90 dBm is reported as "No Signal". |
Radio Type |
The network type supported by the access point: where 'DirectSequencing' refers to 802.11 b, and 'OFDM24' refers to 802.11 g |
Encryption |
Whether encryption is supported and enabled on the access point -- 'WEP' implies that it is, 'None' implies that encryption is not being used. |
Active |
An indication of whether the access point is currently active -- that is, whether a beacon for this access point was detected during the last scan. |
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