diff --git a/scheduler/scheduler.cc b/scheduler/scheduler.cc
index 2806075..ee6a124 100644
--- a/scheduler/scheduler.cc
+++ b/scheduler/scheduler.cc
@@ -20,9 +20,14 @@
  */
 
 #include "scheduler.h"
+#include "one-time-task.h"
+#include "periodic-task.h"
+
 #include <utility>
+#include <boost/make_shared.hpp>
 
 using namespace std;
+using namespace boost;
 
 #define EVLOOP_NO_EXIT_ON_EMPTY 0x04
 
@@ -91,24 +96,45 @@
   m_thread.join();
 }
 
-bool
-Scheduler::addTask(const TaskPtr &task)
+TaskPtr
+Scheduler::scheduleOneTimeTask (SchedulerPtr scheduler, double delay,
+                                const Task::Callback &callback, const Task::Tag &tag)
 {
-  TaskPtr newTask = task;
+  TaskPtr task = make_shared<OneTimeTask> (callback, tag, scheduler, delay);
+  if (scheduler->addTask (task))
+    return task;
+  else
+    return TaskPtr ();
+}
 
+TaskPtr
+Scheduler::schedulePeriodicTask (SchedulerPtr scheduler, IntervalGeneratorPtr delayGenerator,
+                                 const Task::Callback &callback, const Task::Tag &tag)
+{
+  TaskPtr task = make_shared<PeriodicTask> (callback, tag, scheduler, delayGenerator);
+
+  if (scheduler->addTask (task))
+    return task;
+  else
+    return TaskPtr ();
+}
+
+bool
+Scheduler::addTask(TaskPtr newTask)
+{
   if (addToMap(newTask))
   {
     newTask->reset();
     int res = evtimer_add(newTask->ev(), newTask->tv());
     if (res < 0)
     {
-      cout << "evtimer_add failed for " << task->tag() << endl;
+      cout << "evtimer_add failed for " << newTask->tag() << endl;
     }
     return true;
   }
   else
   {
-    cout << "fail to add task: " << task->tag() << endl;
+    cout << "fail to add task: " << newTask->tag() << endl;
   }
 
   return false;
diff --git a/scheduler/scheduler.h b/scheduler/scheduler.h
index 83b9926..e783cf0 100644
--- a/scheduler/scheduler.h
+++ b/scheduler/scheduler.h
@@ -38,6 +38,10 @@
 #include <sys/time.h>
 
 #include "task.h"
+#include "interval-generator.h"
+
+class Scheduler;
+typedef boost::shared_ptr<Scheduler> SchedulerPtr;
 
 /**
  * @brief Scheduler class
@@ -56,9 +60,18 @@
   virtual void
   shutdown();
 
+  // helper method to schedule one-time task
+  static TaskPtr
+  scheduleOneTimeTask (SchedulerPtr scheduler, double delay, const Task::Callback &callback, const Task::Tag &tag);
+
+  // helper method to schedule periodic task
+  static TaskPtr
+  schedulePeriodicTask (SchedulerPtr scheduler, IntervalGeneratorPtr delayGenerator,
+                        const Task::Callback &callback, const Task::Tag &tag);
+  
   // if task with the same tag exists, the task is not added and return false
   virtual bool
-  addTask(const TaskPtr &task);
+  addTask(TaskPtr task);
 
   // delete task by task->tag, regardless of whether it's invoked or not
   virtual void
@@ -117,9 +130,6 @@
   boost::thread m_thread;
 };
 
-class Scheduler;
-typedef boost::shared_ptr<Scheduler> SchedulerPtr;
-
 struct SchedulerException : virtual boost::exception, virtual std::exception { };
 
 #endif // SCHEDULER_H