Research On QoS Mechanism And Its Application Method In LTE

For adapting the development of mobile communication technology in the future, and providing support for the continually enhancing data services,3GPP began the Long Term Evolution(LTE)/System Architecture Evolution (SAE) research project. Considering the character of high-speed and bursting data services, the Evolved Packet System (EPS) makes many improvements in the Quality of Service (QoS) scheme. However, because of the limitation of resource in the wireless communication system, seeking a resource allocation scheme which can not only fulfill the various QoS requrements of different services but also can increase the resources utility becomes a challenge. As for this, this paper mainly research on packet scheduling (PS) and access control (AC), and make some improvements to the previous schemes, ultimately enhancing the user experience. Specifically, this work can be categorized as four parts:(1) As LTE evolves significantly from UMTS, the QoS mechanism of LTE/SAE improves a lot accordingly. This paper firstly do a research on the QoS mechanism of EPS, including end-to-end QoS architecture, radio bearer, QoS parameter, procedure of the QoS establishment and then make a comparison between LTE and UMTS.(2) Radio resource management means the strategically allocation of the radio resource in the wireless communication system. It aims to guarantee the QoS requirements for users as well as enhance the utility of the frequency band by means of dynamically making adjustments to the allocation. This paper then makes analysis of the mechanism of Radio resource management related with QoS in LTE, which includes the granularity, means and procedure of resource allocation, and make packet scheduling and access control the two key function.(3) Packet scheduling algorithm is the core of the packet scheduling. This paper makes a summary of the defects of the previous algorithms applied in LTE based on the research, thus proposing an improvement to those algorithms. The proposed algorithm focuses on the packet loss rate (PLR) requirements of real-time (RT) services, which ensures the throughput of non-real-time (NRT) services while enhancing the delay and PLR requirements of RT services by introducing the PLR feedback mechanism. In addition, this paper simulates the proposed algorithms and the algorithm proves to work as expects.(4) Finally, from the aspects of access control, this paper studies the procedure of access control in LTE. And based on the theory that different services has different access level because of the characters of QoS parameters in LTE, this paper takes access level into account when making the choices. As a result, the improved access control strategy make a promise of delay and data rate as well as balance the relationship between access level differentiation and fairness.This paper focuses on the points above, making a profound study of them and proposing a few improvements. I hope the research on the QoS mechanism of LTE and the policy to enhance QoS by radio resource management will provide a valuable basis for further study in the same direction or the same field.