From 932fed8cc7fbf640045781e95998b6fdfe0f692e Mon Sep 17 00:00:00 2001
From: joxe <joxe>
Date: Thu, 28 Oct 2010 08:54:54 +0000
Subject: [PATCH] improved ETX calculation

---
 core/net/neighbor-info.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/core/net/neighbor-info.c b/core/net/neighbor-info.c
index 4cd8bafc5..594172bc7 100644
--- a/core/net/neighbor-info.c
+++ b/core/net/neighbor-info.c
@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: neighbor-info.c,v 1.16 2010/10/27 00:45:24 nvt-se Exp $
+ * $Id: neighbor-info.c,v 1.17 2010/10/28 08:54:54 joxe Exp $
  */
 /**
  * \file
@@ -50,8 +50,10 @@
 
 #define ETX_LIMIT		15
 #define ETX_SCALE		100
-#define ETX_ALPHA		85
-#define ETX_FIRST_GUESS		3
+#define ETX_ALPHA		90
+#define ETX_FIRST_GUESS		5
+
+#define NOACK_PACKET_ETX        8
 /*---------------------------------------------------------------------------*/
 NEIGHBOR_ATTRIBUTE(uint8_t, etx, NULL);
 
@@ -74,8 +76,9 @@ update_etx(const rimeaddr_t *dest, int packet_etx)
   packet_etx = ETX2FIX(packet_etx);
   new_etx = ((uint16_t)recorded_etx * ETX_ALPHA +
              (uint16_t)packet_etx * (ETX_SCALE - ETX_ALPHA)) / ETX_SCALE;
-  PRINTF("neighbor-info: ETX changed from %d to %d (packet ETX = %d)\n",
-	FIX2ETX(recorded_etx), FIX2ETX(new_etx), FIX2ETX(packet_etx));
+  PRINTF("neighbor-info: ETX changed from %d to %d (packet ETX = %d) %d\n",
+         FIX2ETX(recorded_etx), FIX2ETX(new_etx), FIX2ETX(packet_etx),
+         dest->u8[7]);
 
   if(neighbor_attr_has_neighbor(dest)) {
     neighbor_attr_set_data(&etx, dest, &new_etx);
@@ -123,14 +126,20 @@ neighbor_info_packet_sent(int status, int numtx)
     packet_etx = numtx;
     add_neighbor(dest);
     break;
-  case MAC_TX_ERR:
+  case MAC_TX_COLLISION:
+    packet_etx = numtx;
+    break;
   case MAC_TX_NOACK:
+    packet_etx = NOACK_PACKET_ETX;
+  /* error and collissions will not cause high hits ??? */
+    break;
+  case MAC_TX_ERR:
   default:
-    packet_etx = ETX_LIMIT;
+    packet_etx = 0;
     break;
   }
 
-  update_etx(dest, packet_etx);
+  if (packet_etx > 0) update_etx(dest, packet_etx);
 }
 /*---------------------------------------------------------------------------*/
 void