tailieunhanh - Báo cáo hóa học: " A new and efficient adaptive scheduling packets for the uplink traffic in WiMAX networks"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : A new and efficient adaptive scheduling packets for the uplink traffic in WiMAX networks | Teixeira and Guardieiro EURASIP Journal on Wireless Communications and Networking 2011 2011 1 13 3 EURASIP Journal on http content 2011 1 113 Wireless Communications and Networking a SprlngerOpen Journal RESEARCH Open Access A new and efficient adaptive scheduling packets for the uplink traffic in WiMAX networks Marcio Andrey Teixeira and Paulo Roberto Guardieiro Abstract In this article an adaptive scheduling packets algorithm for the uplink traffic in WiMAX networks is proposed. The proposed algorithm is designed to be completely dynamic mainly in networks that use various modulation and coding schemes MCSs . Using a cross-layer approach and the states of the uplink virtual queues in the base station it was defined a new deadlines-based scheme aiming at limiting the maximum delay to the real-time applications. Moreover a method which interacts with the polling mechanisms of the base station was developed. This method controls the periodicity of sending unicast polling to the real-time and non-real-time service classes in accordance with the quality of service requirements of the applications. The proposed algorithm was evaluated by means of modeling and simulation in environments where various MCSs were used and also in an environment where only one type of MCS was used. The simulations showed satisfactory results in both environments. 1. Introduction The WiMAX technology based on the IEEE standards is a solution for fixed and mobile broadband wireless access BWA networks aiming at providing support to a wide variety of multimedia applications including real-time and non-real-time applications. As a broadband wireless technology WiMAX has been developed with advantages such as high transmission rate and predefined quality of service QoS framework enabling efficient and scalable networks for data video and voice. However the IEEE standards do not define the scheduling algorithm which guarantees the QoS required by the .