Performance Analysis And Optimization For Airborne Voice Over LTE

Airborne Voice over LTE(VoLTE)is an communication scheme by refers to voice communication carried over LTE in the cabin of the ground-to-air wireless communication system.Compared with other voice solutions,the voice quality of VoLTE is greatly improved,the continuous call delay is greatly shortened,and the spectrum utilization is greatly increased.VoLTE is the future evolution direction of voice communication in the all-IP era.Today,the greater the demand for air passenger communication,the poor channel quality and the lack of spectrum resources,VoLTE is considered to be an effective solution for voice quality in the in-cabin voice communication of ground-to-air wireless systems.With the development of civil aviation communication,the demand for air passenger services is increasing.In the ground-to-air wireless communication system composed of aircraft and ground base stations,the ground-to-air wireless channel changes dynamically,affecting the information transmission rate of the ground-to-air data link and affecting the communication quality for passenger.Combining with the needs of China Commercial Aircraft Co.,Ltd.cooperation project” Development and Testing of Prototype of Air-to-Ground Broadband Data Link Communication System”,consider the problem of airborne VoLTE performance degradation in the unstable and relatively dense cabin environment of ground-to-air data link quality.In order to evaluate the quality of service(Quality of Service,QoS)of air passenger voice communication,it is necessary to establish a traffic model that can characterize airborne VoLTE,so as to analyze the voice performance of VoLTE and propose the exclusive airborne VoLTE admission control algorithm,improve the quality of service for passenger voice communication.Therefore,the research content and results are as follows:(1)To solve the dynamic change of the channel capacity of the ground-to-air wireless communication system,the Rice channel with the direct view path is selected to characterize the ground-to-air data link,and the average capacity of the Rice channel is used to quantify the transmission rate of the ground-to-air link transmission channel.The queue model considers the impatient customer distribution to the voice communication delay,that is,establish impatient customer queue model M/M/n+Beta when the waiting time exceeds the impatient of the customer to the wait time,and the customer actively leaves the queue.At this model to analysis the performance of airborne VoLTE.According to the established model,the average waiting time and customer loss rate of airborne VoLTE can be simulated and the average signal-to-noise ratio and passenger-to-speech impatient customer distribution curve.Also,analyze the influences of the passenger arrival rate to voice communication performance.(2)It can be seen that the quality of voice will decrease when the passenger arrival rate increase.Therefore,it is necessary to control the communication request of passengers to prevent the network into a congested state resulting in performance degradation.At present,the admission control algorithm cannot balance the relationship between the call blocking ratio and the call dropping ratio.In this paper,combining the different state in VoLTE with the quality of ground-to-air link channel,the airborne VoLTE dynamic admission control algorithm is innovative proposed.Finally,simulated the exclusive airborne VoLTE dynamic queue admission control algorithm,analyzed the performance of voice under the different average signal-noise ratio,and compared with traditional algorithm.The simulation shows that compared with the traditional admission control algorithm the proposed algorithm can effectively reduce the call dropping rate during the talk spurt state and improve the passenger communication service experience.