Grid of Access Points


This grid of local access points is updated in (semi) realtime -- that is, scans are performed approximately once every 5 seconds.  Pressing one of the first, four column headers will change the way data is sorted in the grid.  That is, you can sort by SSID, BSSID, Channel or Beacon Strength.



The data for each column is 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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