Implementing Poisson Process for consumer requests (exponential distribution for inter-arrival times)
diff --git a/apps/ccnx-consumer.cc b/apps/ccnx-consumer.cc
index 2074a39..fb92c43 100644
--- a/apps/ccnx-consumer.cc
+++ b/apps/ccnx-consumer.cc
@@ -57,11 +57,18 @@
IntegerValue(0),
MakeIntegerAccessor(&CcnxConsumer::m_seq),
MakeIntegerChecker<int32_t>())
-
- .AddAttribute ("OffTime", "Time interval between packets",
- StringValue ("100ms"),
- MakeTimeAccessor (&CcnxConsumer::m_offTime),
- MakeTimeChecker ())
+
+ ///////
+ .AddAttribute ("PayloadSize", "Average size of content object size (to calculate interest generation rate)",
+ UintegerValue (1040),
+ MakeUintegerAccessor (&CcnxConsumer::GetPayloadSize, &CcnxConsumer::SetPayloadSize),
+ MakeUintegerChecker<uint32_t>())
+ .AddAttribute ("MeanRate", "Mean data packet rate (relies on the PayloadSize parameter)",
+ StringValue ("100Kbps"),
+ MakeDataRateAccessor (&CcnxConsumer::GetDesiredRate, &CcnxConsumer::SetDesiredRate),
+ MakeDataRateChecker ())
+ ///////
+
.AddAttribute ("Prefix","CcnxName of the Interest",
StringValue ("/"),
MakeCcnxNameComponentsAccessor (&CcnxConsumer::m_interestName),
@@ -107,9 +114,13 @@
CcnxConsumer::CcnxConsumer ()
: m_rand (0, std::numeric_limits<uint32_t>::max ())
+ , m_desiredRate ("10Kbps")
+ , m_payloadSize (1024)
, m_seq (0)
{
NS_LOG_FUNCTION_NOARGS ();
+
+ UpdateMean (); // not necessary (will be called by ns3 object system anyways), but doesn't hurt
}
void
@@ -155,6 +166,49 @@
&CcnxConsumer::CheckRetxTimeout, this);
}
+void
+CcnxConsumer::UpdateMean ()
+{
+ double mean = 8.0 * m_payloadSize / m_desiredRate.GetBitRate ();
+ m_randExp = ExponentialVariable (mean, 10000 * mean); // set upper limit to inter-arrival time
+}
+
+void
+CcnxConsumer::SetPayloadSize (uint32_t payload)
+{
+ m_payloadSize = payload;
+ UpdateMean ();
+}
+
+uint32_t
+CcnxConsumer::GetPayloadSize () const
+{
+ return m_payloadSize;
+}
+
+void
+CcnxConsumer::SetDesiredRate (DataRate rate)
+{
+ m_desiredRate = rate;
+ UpdateMean ();
+}
+
+DataRate
+CcnxConsumer::GetDesiredRate () const
+{
+ return m_desiredRate;
+}
+
+void
+CcnxConsumer::ScheduleNextPacket ()
+{
+ // schedule periodic packet generation
+
+ m_sendEvent = Simulator::Schedule (
+ Seconds(m_randExp.GetValue ()),
+ &CcnxConsumer::SendPacket, this);
+}
+
// Application Methods
void
CcnxConsumer::StartApplication () // Called at time specified by Start
@@ -163,9 +217,8 @@
// do base stuff
CcnxApp::StartApplication ();
-
- // schedule periodic packet generation
- m_sendEvent = Simulator::Schedule (Seconds(0.0), &CcnxConsumer::SendPacket, this);
+
+ ScheduleNextPacket ();
}
void
@@ -233,11 +286,16 @@
m_seqTimeouts.modify (res.first,
ll::bind(&SeqTimeout::time, ll::_1) = Simulator::Now ());
- m_sendEvent = Simulator::Schedule (m_offTime, &CcnxConsumer::SendPacket, this);
-
m_transmittedInterests (&interestHeader, this, m_face);
+
+ ScheduleNextPacket ();
}
+///////////////////////////////////////////////////
+// Process incoming packets //
+///////////////////////////////////////////////////
+
+
void
CcnxConsumer::OnContentObject (const Ptr<const CcnxContentObjectHeader> &contentObject,
const Ptr<const Packet> &payload)