Research And Optimization On Tail Energy Of Smart Phones In 3G And LTE Network

Smart phones are the most mainstream mobile terminal nowadays. Smart phones let people access the mobile internet for work or entertainment through the ways of the Third Generation and Long Term Evolution communication technology. Smart phones’ limited battery capacity restricts their working endurance time. As one of the three major power consumption components in smart phones, cellular network port produces a large proportion of tail energy after the data transmission, resulting in a waste of electricity. Through the analysis of the tail energy characteristics in 3G and LTE communication network, not only can we learn the specific reasons of such a large proportion of tail energy, but also we can decrease the tail energy consumption in order to reduce the total energy consumption in mobile phone and prolong their working endurance time. Therefore, the analysis of tail energy’s characteristics in smart phones and its optimizations is a significant research work.This paper starts from the formation of tail energy in smart phones, focuses on how to reduce transmission energy in cellular network port effectively and reasonably. Based on the RRC state machine in 3G and LTE network, it proposes a mechanism using the idea of transmission aggregation and data classification to reduce the energy consumption in cellular network port. The main works in this paper are as follows:(1) Research on the optimization of tail energy in smart phones emerged in 3G and LTE network relative theories and its key technologies classify and conclude the existing optimization methods, discuss some of the problems in their designs.(2) Comprehend and research the RRC state machines and their working procedure in 3G and LTE communications technologies, analyze the feasibility of building transfer energy models based on RRC state machine. Design transfer energy counting functions and the working procedure of transfer energy models suitable for the research of tail energy characteristics and optimization, program to realize the transfer energy models. Use the models to simulate the data transmission, analyze and compare the experiment results. The experiment results show that the cellular port transmission energy models can simulate and count the energy generated in the process of data transmission well.(3) The frequency and micro scale characteristics of data transmission in smart phones increase the frequency of occurrence and proportion of tail energy, which decreases the utilization rate of transmission energy. Therefore, this paper proposes a data transmission mechanism based on the idea of aggregation (Aggregate-based Energy Saving Data Transmission, A-ESDT). This mechanism takes data transmission types and cellular port recent RRC state together to decide whether transmits the data now or does it later. The results of the transfer models experiment show that the A-ESDT mechanism enhance the energy efficiency compared to the normal mechanism, but its efficiency is not stable after many times aggregation and decreases as the data transmission times increase.(4) Aim at solving the problem of unstable energy saving efficiency in A-ESDT, this paper proposes an evolved A-ESDT(EA-ESDT) mechanism. This evolved mechanism takes the periodicity of instant and heartbeat type data and the earliest deadline in the waiting queue together into consideration, adds the probability prediction into the original data transmission judgment to weigh the opportunity cost. The experimental simulation results show that:the EA-ESDT can achieve stable energy saving efficiency, which maintains at about 27%.This paper makes some progress in the optimization of tail energy in 3G and LTE network, provides a new idea for the solution of enhancing transmission energy efficiency in smart phones, Its research has scientific meaning and actual application value.