diff --git a/scheduler/schedule.cpp b/scheduler/schedule.cpp
index 71e1903..b487848 100644
--- a/scheduler/schedule.cpp
+++ b/scheduler/schedule.cpp
@@ -293,6 +293,8 @@ int SensorScheduler::GetNextDuration(int short_addr, int &next_task_id) {
         id = iter->second;
     }
     long current_ts = GetLocalTs(); 
+    nth_wave_start_slice_ = (current_ts_ - start_timestamp_) / wave_form_send_interval_;
+    current_wave_start_ts_ = nth_wave_start_slice_ * wave_form_send_interval_ + start_timestamp_;
     long next_ts = CalcNextTimestamp(id, short_addr, next_task_id);
     int duration = next_ts - current_ts;
     if (duration < 0 || duration > eigen_value_send_interval_) {