Module Name:	src
Committed By:	rpaulo
Date:		Thu Jun  8 20:56:41 UTC 2006

Modified Files:
	src/sys/dev/ic: rt2661.c rt2661var.h

Log Message:
Bring the following change from OpenBSD:

  Keep track of the average RSSI using an Exponential Moving Average (EMA).
  Use it to dynamically tune radio receive sensitivity.

  The idea is simple:
  - increase sensitivity when the RSSI is bad to optimize throughput on
    long distance to the AP, and
  - decrease sensitivity when the RSSI is good to reduce noise level and
    optimize throughput on short distance to the AP

  The EMA allows to smooth RSSI variations so we don't end up changing the
  sensitivity too frequently.  We check if it would be worth updating the
  sensitivity every one second.
  RSSI thresholds were taken from the Ralink Tech. Linux driver.


To generate a diff of this commit:
cvs rdiff -r1.5 -r1.6 src/sys/dev/ic/rt2661.c
cvs rdiff -r1.2 -r1.3 src/sys/dev/ic/rt2661var.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.