Asus B and W PCI CARD - Manual (Page 61)

60 ASUS SpaceLink B&W PCI Card
Chapter 3 - Wireless LAN Reference
Chapter 3
3.5.3 Monitor
Directed link state test with one particular wireless network, including:
RSSI: This indicates the value of received signal strength of the last received
frame. In principle, the higher the RSSI, the better your communications
quality.
Throughput: This sends a specified number of data packets to the remote
host and calculates the average megabytes per second.
During the test, the Start button toggles to Stop. You can click Start button
to begin the link test and click Stop button at any time to terminate the test.