rtt-estimator.h

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
//
// Copyright (c) 2006 Georgia Tech Research Corporation
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2 as
// published by the Free Software Foundation;
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// Author: Rajib Bhattacharjea<raj.b@gatech.edu>
//

// Georgia Tech Network Simulator - Round Trip Time Estimation Class
// George F. Riley.  Georgia Tech, Spring 2002


#ifndef RTT_ESTIMATOR_H
#define RTT_ESTIMATOR_H

#include "ns3/nstime.h"
#include "ns3/object.h"

namespace ns3 {

class RttEstimator : public Object {
public:
  static TypeId GetTypeId (void);

  RttEstimator();
  RttEstimator (const RttEstimator& r);

  virtual ~RttEstimator();

  virtual TypeId GetInstanceTypeId (void) const;

  virtual void  Measurement (Time t) = 0;

  virtual Ptr<RttEstimator> Copy () const = 0;

  virtual void Reset ();

  Time GetEstimate (void) const;

  Time GetVariation (void) const;

  uint32_t GetNSamples (void) const;

private:
  Time m_initialEstimatedRtt; 

protected:
  Time         m_estimatedRtt;            
  Time         m_estimatedVariation;   
  uint32_t     m_nSamples;                
};

class RttMeanDeviation : public RttEstimator {
public:
  static TypeId GetTypeId (void);

  RttMeanDeviation ();

  RttMeanDeviation (const RttMeanDeviation& r);

  virtual TypeId GetInstanceTypeId (void) const;

  void Measurement (Time measure);

  Ptr<RttEstimator> Copy () const;

  void Reset ();

private:
  uint32_t CheckForReciprocalPowerOfTwo (double val) const;
  void IntegerUpdate (Time m, uint32_t rttShift, uint32_t variationShift);
  void FloatingPointUpdate (Time m);
  double       m_alpha;       
  double       m_beta;        

};

} // namespace ns3

#endif /* RTT_ESTIMATOR_H */