diff --git a/core/chronoshare-common.hpp b/core/chronoshare-common.hpp
new file mode 100644
index 0000000..44b5873
--- /dev/null
+++ b/core/chronoshare-common.hpp
@@ -0,0 +1,52 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016, Regents of the University of California.
+ *
+ * This file is part of ChronoShare, a decentralized file sharing application over NDN.
+ *
+ * ChronoShare is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * ChronoShare 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 copies of the GNU General Public License along with
+ * ChronoShare, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ChronoShare authors and contributors.
+ */
+
+#ifndef CHRONOSHARE_CORE_COMMON_HPP
+#define CHRONOSHARE_CORE_COMMON_HPP
+
+#include "core/chronoshare-config.hpp"
+
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+#include <functional>
+#include <limits>
+#include <memory>
+#include <stdexcept>
+#include <string>
+#include <type_traits>
+#include <unistd.h>
+
+#include <boost/assert.hpp>
+#include <boost/concept_check.hpp>
+#include <boost/exception/all.hpp>
+#include <boost/noncopyable.hpp>
+#include <boost/throw_exception.hpp>
+
+namespace ndn {
+namespace chronoshare {
+
+using std::shared_ptr;
+using std::make_shared;
+
+} // chronoshare
+} // ndn
+
+#endif // CHRONOSHARE_CORE_COMMON_HPP
diff --git a/core/interval-generator.hpp b/core/interval-generator.hpp
new file mode 100644
index 0000000..6e617cf
--- /dev/null
+++ b/core/interval-generator.hpp
@@ -0,0 +1,47 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016, Regents of the University of California.
+ *
+ * This file is part of ChronoShare, a decentralized file sharing application over NDN.
+ *
+ * ChronoShare is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * ChronoShare 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 copies of the GNU General Public License along with
+ * ChronoShare, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ChronoShare authors and contributors.
+ */
+
+#ifndef CHRONOSHARE_CORE_INTERVAL_GENERATOR_HPP
+#define CHRONOSHARE_CORE_INTERVAL_GENERATOR_HPP
+
+#include "chronoshare-common.hpp"
+
+namespace ndn {
+namespace chronoshare {
+
+class IntervalGenerator;
+typedef shared_ptr<IntervalGenerator> IntervalGeneratorPtr;
+
+class IntervalGenerator
+{
+public:
+  virtual
+  ~IntervalGenerator()
+  {
+  }
+
+  virtual double
+  nextInterval() = 0;
+};
+
+} // chronoshare
+} // ndn
+
+#endif // CHRONOSHARE_CORE_INTERVAL_GENERATOR_HPP
diff --git a/core/logging.cpp b/core/logging.cpp
new file mode 100644
index 0000000..08030c9
--- /dev/null
+++ b/core/logging.cpp
@@ -0,0 +1,62 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016, Regents of the University of California.
+ *
+ * This file is part of ChronoShare, a decentralized file sharing application over NDN.
+ *
+ * ChronoShare is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * ChronoShare 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 copies of the GNU General Public License along with
+ * ChronoShare, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ChronoShare authors and contributors.
+ */
+
+#include "logging.hpp"
+
+#include <log4cxx/basicconfigurator.h>
+#include <log4cxx/consoleappender.h>
+#include <log4cxx/defaultconfigurator.h>
+#include <log4cxx/helpers/exception.h>
+#include <log4cxx/level.h>
+#include <log4cxx/logger.h>
+#include <log4cxx/patternlayout.h>
+#include <log4cxx/propertyconfigurator.h>
+
+#include <unistd.h>
+
+namespace ndn {
+namespace chronoshare {
+
+using namespace log4cxx;
+using namespace log4cxx::helpers;
+
+void
+INIT_LOGGERS()
+{
+  static bool configured = false;
+
+  if (configured)
+    return;
+
+  if (access("log4cxx.properties", R_OK) == 0)
+    PropertyConfigurator::configureAndWatch("log4cxx.properties");
+  else {
+    PatternLayoutPtr layout(new PatternLayout("%d{HH:mm:ss} %p %c{1} - %m%n"));
+    ConsoleAppenderPtr appender(new ConsoleAppender(layout));
+
+    BasicConfigurator::configure(appender);
+    Logger::getRootLogger()->setLevel(log4cxx::Level::getInfo());
+  }
+
+  configured = true;
+}
+
+} // chronoshare
+} // ndn
diff --git a/core/logging.hpp b/core/logging.hpp
new file mode 100644
index 0000000..86e1bf0
--- /dev/null
+++ b/core/logging.hpp
@@ -0,0 +1,65 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016, Regents of the University of California.
+ *
+ * This file is part of ChronoShare, a decentralized file sharing application over NDN.
+ *
+ * ChronoShare is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * ChronoShare 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 copies of the GNU General Public License along with
+ * ChronoShare, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ChronoShare authors and contributors.
+ */
+
+#ifndef CHRONOSHARE_CORE_LOGGING_HPP
+#define CHRONOSHARE_CORE_LOGGING_HPP
+
+#include "core/chronoshare-config.hpp"
+
+#include <log4cxx/logger.h>
+
+namespace ndn {
+namespace chronoshare {
+
+#define MEMBER_LOGGER static log4cxx::LoggerPtr staticModuleLogger;
+
+#define INIT_MEMBER_LOGGER(className, name) \
+  log4cxx::LoggerPtr className::staticModuleLogger = log4cxx::Logger::getLogger(name);
+
+#define INIT_LOGGER(name) \
+  static log4cxx::LoggerPtr staticModuleLogger = log4cxx::Logger::getLogger(name);
+
+#define _LOG_DEBUG(x) LOG4CXX_DEBUG(staticModuleLogger, x);
+
+#define _LOG_TRACE(x) LOG4CXX_TRACE(staticModuleLogger, x);
+
+#define _LOG_FUNCTION(x) LOG4CXX_TRACE(staticModuleLogger, __FUNCTION__ << "(" << x << ")");
+
+#define _LOG_FUNCTION_NOARGS LOG4CXX_TRACE(staticModuleLogger, __FUNCTION__ << "()");
+
+#define _LOG_ERROR(x) LOG4CXX_ERROR(staticModuleLogger, x);
+
+#define _LOG_ERROR_COND(cond, x) \
+  if (cond) {                    \
+    _LOG_ERROR(x)                \
+  }
+
+#define _LOG_DEBUG_COND(cond, x) \
+  if (cond) {                    \
+    _LOG_DEBUG(x)                \
+  }
+
+void
+INIT_LOGGERS();
+
+} // chronoshare
+} // ndn
+
+#endif // CHRONOSHARE_CORE_LOGGING_HPP
diff --git a/core/random-interval-generator.hpp b/core/random-interval-generator.hpp
new file mode 100644
index 0000000..ceeef60
--- /dev/null
+++ b/core/random-interval-generator.hpp
@@ -0,0 +1,108 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016, Regents of the University of California.
+ *
+ * This file is part of ChronoShare, a decentralized file sharing application over NDN.
+ *
+ * ChronoShare is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * ChronoShare 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 copies of the GNU General Public License along with
+ * ChronoShare, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ChronoShare authors and contributors.
+ */
+
+#ifndef CHRONOSHARE_CORE_RANDOM_INTERVAL_GENERATOR_HPP
+#define CHRONOSHARE_CORE_RANDOM_INTERVAL_GENERATOR_HPP
+
+#include "interval-generator.hpp"
+
+#include <boost/date_time/posix_time/posix_time_types.hpp>
+#include <boost/random/mersenne_twister.hpp>
+#include <boost/random/uniform_real.hpp>
+#include <boost/random/variate_generator.hpp>
+
+namespace ndn {
+namespace chronoshare {
+
+// generates intervals with uniform distribution
+class RandomIntervalGenerator : public IntervalGenerator
+{
+public:
+  enum class Direction {
+    UP = 1,
+    DOWN = 2,
+    EVEN = 3
+  };
+
+public:
+  // percent is random-range/interval; e.g. if interval is 10 and you wish the random-range to be 2
+  // e.g. 9 ~ 11, percent = 0.2
+  // direction shifts the random range; e.g. in the above example, UP would produce a range of
+  // 10 ~ 12, DOWN of 8 ~ 10, and EVEN of 9 ~ 11
+  RandomIntervalGenerator(double interval, double percent, Direction direction = Direction::EVEN)
+    // : m_rng(time(NULL))
+    : m_rng(static_cast<int>(
+        boost::posix_time::microsec_clock::local_time().time_of_day().total_nanoseconds())),
+      m_dist(0.0, fractional(percent)),
+      m_random(m_rng, m_dist),
+      m_direction(direction),
+      m_percent(percent),
+      m_interval(interval)
+  {
+  }
+
+  virtual ~RandomIntervalGenerator()
+  {
+  }
+
+  virtual double
+  nextInterval()
+  {
+    double percent = m_random();
+    double interval = m_interval;
+    switch (m_direction) {
+      case Direction::UP:
+        interval = m_interval * (1.0 + percent);
+        break;
+      case Direction::DOWN:
+        interval = m_interval * (1.0 - percent);
+        break;
+      case Direction::EVEN:
+        interval = m_interval * (1.0 - m_percent / 2.0 + percent);
+        break;
+      default:
+        break;
+    }
+
+    return interval;
+  }
+
+private:
+  inline double
+  fractional(double x)
+  {
+    double dummy;
+    return std::abs<double>(modf(x, &dummy));
+  }
+
+private:
+  typedef boost::mt19937 RNG_TYPE;
+  RNG_TYPE m_rng;
+  boost::uniform_real<> m_dist;
+  boost::variate_generator<RNG_TYPE&, boost::uniform_real<>> m_random;
+  Direction m_direction;
+  double m_percent;
+  double m_interval;
+};
+
+} // chronoshare
+} // ndn
+
+#endif // CHRONOSHARE_CORE_RANDOM_INTERVAL_GENERATOR_HPP