From 01e9498dd9849ec8116b9b617ac6f9067b63dec5 Mon Sep 17 00:00:00 2001
From: fros4943 <fros4943>
Date: Wed, 25 Nov 2009 10:36:08 +0000
Subject: [PATCH] radio medium update: receiving nodes that become interfered
 still receive connection data, but may (should) choose to ignore or corrupt
 it. this solves a problem with half-filled FIFO buffers on CC2420 radio
 platforms

+ minor fixes: the received signal strength is the maximum of all active connection, and a transmitting radio may still be interfered
---
 .../java/se/sics/cooja/radiomediums/UDGM.java | 23 +++++++++++++------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/tools/cooja/java/se/sics/cooja/radiomediums/UDGM.java b/tools/cooja/java/se/sics/cooja/radiomediums/UDGM.java
index bfddd8290..b52c7e696 100644
--- a/tools/cooja/java/se/sics/cooja/radiomediums/UDGM.java
+++ b/tools/cooja/java/se/sics/cooja/radiomediums/UDGM.java
@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: UDGM.java,v 1.27 2009/10/27 10:36:01 fros4943 Exp $
+ * $Id: UDGM.java,v 1.28 2009/11/25 10:36:08 fros4943 Exp $
  */
 
 package se.sics.cooja.radiomediums;
@@ -215,7 +215,8 @@ public class UDGM extends AbstractRadioMedium {
         if (recv.isInterfered()) {
           /* Was interfered: keep interfering */
           newConnection.addInterfered(recv);
-
+        } else if (recv.isTransmitting()) {
+          newConnection.addInterfered(recv);
         } else if (recv.isReceiving() ||
             (SUCCESS_RATIO_RX < 1.0 && random.nextDouble() > SUCCESS_RATIO_RX)) {
           /* Was receiving, or reception failed: start interfering */
@@ -226,7 +227,6 @@ public class UDGM extends AbstractRadioMedium {
           for (RadioConnection conn : getActiveConnections()) {
             for (Radio dstRadio : conn.getDestinations()) {
               if (dstRadio == recv) {
-                conn.removeDestination(recv);
                 conn.addInterfered(recv);
                 break;
               }
@@ -249,7 +249,7 @@ public class UDGM extends AbstractRadioMedium {
 
   public void updateSignalStrengths() {
     /* Override: uses distance as signal strength factor */
-
+    
     /* Reset signal strengths */
     for (Radio radio : getRegisteredRadios()) {
       radio.setCurrentSignalStrength(SS_NOTHING);
@@ -258,7 +258,9 @@ public class UDGM extends AbstractRadioMedium {
     /* Set signal strength to below strong on destinations */
     RadioConnection[] conns = getActiveConnections();
     for (RadioConnection conn : conns) {
-      conn.getSource().setCurrentSignalStrength(SS_STRONG);
+      if (conn.getSource().getCurrentSignalStrength() < SS_STRONG) {
+        conn.getSource().setCurrentSignalStrength(SS_STRONG);
+      }
       for (Radio dstRadio : conn.getDestinations()) {
         double dist = conn.getSource().getPosition().getDistanceTo(dstRadio.getPosition());
 
@@ -267,7 +269,9 @@ public class UDGM extends AbstractRadioMedium {
         double distFactor = dist/maxTxDist;
 
         double signalStrength = SS_STRONG + distFactor*(SS_WEAK - SS_STRONG);
-        dstRadio.setCurrentSignalStrength(signalStrength);
+        if (dstRadio.getCurrentSignalStrength() < signalStrength) {
+          dstRadio.setCurrentSignalStrength(signalStrength);
+        }
       }
     }
 
@@ -282,9 +286,14 @@ public class UDGM extends AbstractRadioMedium {
 
         if (distFactor < 1) {
           double signalStrength = SS_STRONG + distFactor*(SS_WEAK - SS_STRONG);
-          intfRadio.setCurrentSignalStrength(signalStrength);
+          if (intfRadio.getCurrentSignalStrength() < signalStrength) {
+            intfRadio.setCurrentSignalStrength(signalStrength);
+          }
         } else {
           intfRadio.setCurrentSignalStrength(SS_WEAK);
+          if (intfRadio.getCurrentSignalStrength() < SS_WEAK) {
+            intfRadio.setCurrentSignalStrength(SS_WEAK);
+          }
         }
 
         if (!intfRadio.isInterfered()) {