diff --git a/src/lr-wpan/test/lr-wpan-collision-test.cc b/src/lr-wpan/test/lr-wpan-collision-test.cc
index 3a7ef02fb..067b1bc35 100644
--- a/src/lr-wpan/test/lr-wpan-collision-test.cc
+++ b/src/lr-wpan/test/lr-wpan-collision-test.cc
@@ -131,44 +131,44 @@ LrWpanCollisionTestCase::DoRun (void)
   params.m_msduHandle = 0;
   // params.m_txOptions = TX_OPTION_ACK;
 
-//  // First case: concurrent tx and no ACKs
-//  std::cout << "*** First test " << std::endl;
-//  m_rxPackets = 0;
-//  params.m_dstAddr = Mac16Address ("00:02");
-//  Simulator::Schedule (Seconds (0.0),
-//                       &LrWpanMac::McpsDataRequest,
-//                       dev0->GetMac (), params, p0);
-//
-//  params.m_dstAddr = Mac16Address ("00:01");
-//  Simulator::Schedule (Seconds (0.0),
-//                       &LrWpanMac::McpsDataRequest,
-//                       dev1->GetMac (), params, p1);
-//
-//  Simulator::Run ();
-//
-//  NS_TEST_EXPECT_MSG_EQ (m_rxPackets, 0, "Not received a packet (as expected)");
-//
-//  // Second case: concurrent tx and ACKs
-//  std::cout << "*** Second test " << std::endl;
-//  m_rxPackets = 0;
-//  params.m_txOptions = TX_OPTION_ACK;
-//
-//  params.m_dstAddr = Mac16Address ("00:02");
-//  Simulator::Schedule (Seconds (0.0),
-//                       &LrWpanMac::McpsDataRequest,
-//                       dev0->GetMac (), params, p0);
-//
-//  params.m_dstAddr = Mac16Address ("00:01");
-//  Simulator::Schedule (Seconds (0.0),
-//                       &LrWpanMac::McpsDataRequest,
-//                       dev1->GetMac (), params, p1);
-//
-//  Simulator::Run ();
-//
-//  NS_TEST_EXPECT_MSG_EQ (m_rxPackets, 1, "Received a packet (as expected)");
+  // First case: concurrent tx and no ACKs
+  std::cout << "*** First test " << std::endl;
+  m_rxPackets = 0;
+  params.m_dstAddr = Mac16Address ("00:02");
+  Simulator::Schedule (Seconds (0.1),
+                       &LrWpanMac::McpsDataRequest,
+                       dev0->GetMac (), params, p0);
+
+  params.m_dstAddr = Mac16Address ("00:01");
+  Simulator::Schedule (Seconds (0.1),
+                       &LrWpanMac::McpsDataRequest,
+                       dev1->GetMac (), params, p1);
+
+  Simulator::Run ();
+
+  NS_TEST_EXPECT_MSG_EQ (m_rxPackets, 0, "Not received a packet (as expected)");
+
+  // Second case: concurrent tx and ACKs
+  std::cout << "*** Second test " << std::endl;
+  m_rxPackets = 0;
+  params.m_txOptions = TX_OPTION_ACK;
+
+  params.m_dstAddr = Mac16Address ("00:02");
+  Simulator::Schedule (Seconds (0.1),
+                       &LrWpanMac::McpsDataRequest,
+                       dev0->GetMac (), params, p0);
+
+  params.m_dstAddr = Mac16Address ("00:01");
+  Simulator::Schedule (Seconds (0.1),
+                       &LrWpanMac::McpsDataRequest,
+                       dev1->GetMac (), params, p1);
+
+  Simulator::Run ();
+
+  NS_TEST_EXPECT_MSG_EQ (m_rxPackets, 1, "Received a packet (as expected)");
 
   // Third case: two concurrent tx and no ACKs
-  std::cout << "*** Third test " << Seconds (0.0) << " " << Seconds (0.0001) << std::endl;
+  std::cout << "*** Third test " << std::endl;
   m_rxPackets = 0;
   params.m_txOptions = 0;
 
@@ -191,25 +191,25 @@ LrWpanCollisionTestCase::DoRun (void)
   std::cout << "m_rxPackets = " << int(m_rxPackets) << std::endl;
   NS_TEST_EXPECT_MSG_EQ (m_rxPackets, 0, "Received a packet (as expected)");
 
-//  // Fourth case: two concurrent tx and ACKs
-//  std::cout << "*** Fourth test " << std::endl;
-//  m_rxPackets = 0;
-//  params.m_txOptions = TX_OPTION_ACK;
-//
-//  params.m_dstAddr = Mac16Address ("00:01");
-//  Simulator::Schedule (Seconds (0.0),
-//                       &LrWpanMac::McpsDataRequest,
-//                       dev1->GetMac (), params, p0);
-//
-//  params.m_dstAddr = Mac16Address ("00:01");
-//  Simulator::Schedule (Seconds (0.0),
-//                       &LrWpanMac::McpsDataRequest,
-//                       dev2->GetMac (), params, p1);
-//
-//  Simulator::Run ();
-//
-//  std::cout << "m_rxPackets = " << int(m_rxPackets) << std::endl;
-//  NS_TEST_EXPECT_MSG_EQ (m_rxPackets, 2, "Received two packets (as expected)");
+  // Fourth case: two concurrent tx and ACKs
+  std::cout << "*** Fourth test " << std::endl;
+  m_rxPackets = 0;
+  params.m_txOptions = TX_OPTION_ACK;
+
+  params.m_dstAddr = Mac16Address ("00:01");
+  Simulator::Schedule (Seconds (0.1),
+                       &LrWpanMac::McpsDataRequest,
+                       dev1->GetMac (), params, p0);
+
+  params.m_dstAddr = Mac16Address ("00:01");
+  Simulator::Schedule (Seconds (0.1),
+                       &LrWpanMac::McpsDataRequest,
+                       dev2->GetMac (), params, p1);
+
+  Simulator::Run ();
+
+  std::cout << "m_rxPackets = " << int(m_rxPackets) << std::endl;
+  NS_TEST_EXPECT_MSG_EQ (m_rxPackets, 2, "Received two packets (as expected)");
 
   Simulator::Destroy ();
 }