From c32c2ffd59abb323a34aea49ec7b8cc5cc91f7d7 Mon Sep 17 00:00:00 2001
From: scipio <scipio>
Date: Mon, 21 May 2007 22:08:29 +0000
Subject: [PATCH] Include false positive acknowledgements. Adjusted default
 constants to reduce RAM footprint of noise model.

---
 tos/lib/tossim/CpmModelC.nc | 13 +++++++++++++
 tos/lib/tossim/sim_noise.h  |  4 ++--
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/tos/lib/tossim/CpmModelC.nc b/tos/lib/tossim/CpmModelC.nc
index 5e6b61e1..59f94e10 100644
--- a/tos/lib/tossim/CpmModelC.nc
+++ b/tos/lib/tossim/CpmModelC.nc
@@ -329,6 +329,19 @@ implementation {
       receiving = 0;
     } // If the packet was lost, then we're searching for new packets again
     else {
+      if (RandomUniform() < 0.001) {
+	dbg("CpmModelC,SNRLoss", "Packet was technically lost, but TOSSIM introduces an ack false positive rate.\n");
+	if (mine->ack && signal Model.shouldAck(mine->msg)) {
+	  dbg_clear("CpmModelC", " scheduling ack.\n");
+	  sim_gain_schedule_ack(mine->source, sim_time() + 1, mine);
+	}
+	else { // Otherwise free the receive_message_t*
+	  free_receive_message(mine);
+	}
+      }
+      else {
+	free_receive_message(mine);
+      }
       receiving = 0;
       dbg_clear("CpmModelC,SNRLoss", "  -packet was lost.\n");
     }
diff --git a/tos/lib/tossim/sim_noise.h b/tos/lib/tossim/sim_noise.h
index a46aea9b..73c9b52c 100644
--- a/tos/lib/tossim/sim_noise.h
+++ b/tos/lib/tossim/sim_noise.h
@@ -48,8 +48,8 @@ enum {
   NOISE_BIN_SIZE = (NOISE_MAX - NOISE_MIN)/NOISE_QUANTIZE_INTERVAL,
   NOISE_HISTORY = 20,
   NOISE_DEFAULT_ELEMENT_SIZE = 8,
-  NOISE_HASHTABLE_SIZE = 8192,
-  NOISE_MIN_TRACE = 1024, 
+  NOISE_HASHTABLE_SIZE = 128,
+  NOISE_MIN_TRACE = 128, 
 };
   
 typedef struct sim_noise_hash_t {
-- 
2.39.2