From b604bf2d7abcbc5e490623956173ff9bb2c267f1 Mon Sep 17 00:00:00 2001
From: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
Date: Tue, 11 Dec 2007 17:48:09 +0100
Subject: [PATCH] estimation delay and jitter

---
 src/contrib/delay-jitter-estimation.cc | 98 ++++++++++++++++++++++++++
 src/contrib/delay-jitter-estimation.h  | 28 ++++++++
 2 files changed, 126 insertions(+)
 create mode 100644 src/contrib/delay-jitter-estimation.cc
 create mode 100644 src/contrib/delay-jitter-estimation.h

diff --git a/src/contrib/delay-jitter-estimation.cc b/src/contrib/delay-jitter-estimation.cc
new file mode 100644
index 000000000..007359758
--- /dev/null
+++ b/src/contrib/delay-jitter-estimation.cc
@@ -0,0 +1,98 @@
+
+#include "delay-jitter-estimation.h"
+#include "ns3/tag.h"
+#include "ns3/simulator.h"
+
+namespace {
+
+class TimestampTag : public ns3::Tag
+{
+public:
+  TimestampTag ();
+  static uint32_t GetUid (void);
+  void Print (std::ostream &os) const;
+  void Serialize (ns3::Buffer::Iterator start) const;
+  uint32_t Deserialize (ns3::Buffer::Iterator start);
+  uint32_t GetSerializedSize (void) const;
+
+  ns3::Time GetTxTime (void) const;
+private:
+  uint64_t m_creationTime;
+};
+
+TimestampTag::TimestampTag ()
+  : m_creationTime (ns3::Simulator::Now ().GetTimeStep ())
+{}
+uint32_t 
+TimestampTag::GetUid (void)
+{
+  static uint32_t uid = ns3::Tag::AllocateUid<TimestampTag> ("mathieu.paper.TimestampTag");
+  return uid;
+}
+void 
+TimestampTag::Print (std::ostream &os) const
+{
+  os << ns3::TimeStep (m_creationTime);
+}
+void 
+TimestampTag::Serialize (ns3::Buffer::Iterator start) const
+{}
+uint32_t 
+TimestampTag::Deserialize (ns3::Buffer::Iterator start)
+{
+  return 0;
+}
+uint32_t 
+TimestampTag::GetSerializedSize (void) const
+{
+  return 0;
+}
+ns3::Time 
+TimestampTag::GetTxTime (void) const
+{
+  return ns3::TimeStep (m_creationTime);
+}
+
+}
+
+namespace ns3 {
+
+DelayJitterEstimation::DelayJitterEstimation ()
+  : m_previousRx (Simulator::Now ()),
+    m_previousRxTx (Simulator::Now ()),
+    m_jitter (Seconds (0.0)),
+    m_delay (Seconds (0.0))
+{}
+void 
+DelayJitterEstimation::PrepareTx (Ptr<const Packet> packet)
+{
+  TimestampTag tag;
+  packet->AddTag (tag);
+}
+void 
+DelayJitterEstimation::RecordRx (Ptr<const Packet> packet)
+{
+  TimestampTag tag;
+  bool found = packet->PeekTag (tag);
+  NS_ASSERT (found);
+  tag.GetTxTime ();
+
+  Time delta = (Simulator::Now () - m_previousRx) - (tag.GetTxTime () - m_previousRxTx);
+  m_jitter += (Abs (delta) - m_jitter ) / Scalar (16.0);
+  m_previousRx = Simulator::Now ();
+  m_previousRxTx = tag.GetTxTime ();
+  m_delay = Simulator::Now () - tag.GetTxTime ();
+}
+
+Time 
+DelayJitterEstimation::GetLastDelay (void) const
+{
+  return m_delay;
+}
+Time
+DelayJitterEstimation::GetLastJitter (void) const
+{
+  return m_jitter;
+}
+
+} // namespace ns3
diff --git a/src/contrib/delay-jitter-estimation.h b/src/contrib/delay-jitter-estimation.h
new file mode 100644
index 000000000..d4dc0e5bf
--- /dev/null
+++ b/src/contrib/delay-jitter-estimation.h
@@ -0,0 +1,28 @@
+#ifndef DELAY_JITTER_ESTIMATION_H
+#define DELAY_JITTER_ESTIMATION_H
+
+#include "ns3/nstime.h"
+#include "ns3/packet.h"
+
+namespace ns3 {
+
+class DelayJitterEstimation
+{
+public:
+  DelayJitterEstimation ();
+  static void PrepareTx (Ptr<const Packet> packet);
+  void RecordRx (Ptr<const Packet> packet);
+
+  Time GetLastDelay (void) const;
+  Time GetLastJitter (void) const;
+
+private:
+  Time m_previousRx;
+  Time m_previousRxTx;
+  Time m_jitter;
+  Time m_delay;
+};
+
+} // namespace ns3
+
+#endif /* DELAY_JITTER_ESTIMATION_H */