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.


Also, clean a few things while I'm here:
- account for FCS when determining if RTS protection must be used
- fix check for whether WEP encryption is needed or not
- encrypt mgmt frames if we need to (shared authmode)
- cosmetic tweaks

1 files changed, 4 insertions, 1 deletions

diff --git a/sys/dev/ic/rt2661var.h b/sys/dev/ic/rt2661var.h
index bbfd1071253..3d76c96ea25 100644
--- a/sys/dev/ic/rt2661var.h
+++ b/sys/dev/ic/rt2661var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rt2661var.h,v 1.5 2006/06/01 16:24:22 robert Exp $	*/
+/*	$OpenBSD: rt2661var.h,v 1.6 2006/06/08 19:58:44 damien Exp $	*/
 
 /*-
  * Copyright (c) 2006
@@ -141,6 +141,9 @@ struct rt2661_softc {
 	int				rssi_2ghz_corr;
 	int				rssi_5ghz_corr;
 
+	int				ncalls;
+	int				avg_rssi;
+
 	uint8_t				bbp18;
 	uint8_t				bbp21;
 	uint8_t				bbp22;