Research On Efficient Scheduling Strategy For IoT Devices

The Internet of Things system has put forth a demand for efficient communication,which made the energy comsumption of equipment,and the time delay in receiving and data processing our essential topic.In consideration of both the energy saving and the timeliness of data reception,it is necessary to develop a wake-up mechanism for the equipment to receive and process data.The traditional measurement indexes of data reception generally include data delay,energy efficiency,etc.This thesis includes studies of an efficient scheduling strategy for IoT devices,based mainly on the concepts of discontinuous receiving and also small data transmission.The main contributions of this thesis are as follows:(1)The energy efficiency analysis of multi-state equipment with DRX function under RRC connected state is carried out.In many cases,if the user device has been scheduled,and it is receiving or sending packets,it will,in most cases,be scheduled again within a very short period of time.The multiple scheduling is required because the base station may not be able to send all the data in the cache through a single scheduler.Therefore,in order to reduce delay,after decoding and receiving data,IoT devices will remain in wakeup state for a certain period of time according to the information marked on data packets.Also,IoT devices can also go to sleep to save energy according to the information on the packet.This thesis uses Markov state transition diagram and state transition matrix to analyze the energy efficiency improvement of IoT devices that use this strategy.(2)The energy efficiency analysis of equipment with small data transmission mechanism under RRC inactive state is carried out.When the user device is in the RRC inactive state,the wireless connection is suspended,but the core connection remains.IoT devices can transfer small data during random access without prior transition to the RRC connection state,which may greatly reduce latency,energy consumption and signal overhead on the device side.The method of classification and comparison is used here to analyze the energy efficiency of IoT devices with small data transmission mechanism.The average energy efficiency of the system with the optimal efficiency start period is 6.56%,and the maximum energy efficiency is 104.85%.