| dc.description.abstract | The design of QoS in WiMAX provides better quality in real-time services over wireless network. The new scheduling service, named ERT-VR, in IEEE 802.16e standard provides the jitter guarantee parameter to enhance the quality of real time applications.
Unlike the fixed network, which only considers the instantaneous traffic and queue condition, the factors of multipath and doppler in radio environment will affect the transmission quality. Therefore, the channel condition shall be considered for the scheduling scheme in IEEE 802.16e network. The IEEE 802.16e network is a kind of the wireless technologies, the SNR may be changed quickly by time and place especially in mobile condition. In this paper, we propose a cross-layer scheduling in order to feedback from the information of PHY layer quickly and accurately to the MAC layer.
The E-model is a common way to evaluate whether the data network is well performed in carring VoIP traffic. In E-model, the important element of equipment impairment factor is jitter. And, the IEEE 802.16e standard also regards jitter as one of the important factors in ERT-VR scheduling service. In this paper, a jitter guanarteed scheduling scheme for ERT-VR service is proposed. During the simulation, the UGS scheduling service is assumed to be unidirectional real-time service such as radio service, or provide fixed bandwidth service such as T1 service. And, the RT-VR scheduling service is regarded as an important role in video transmission such MPEG. The ERT-VR scheduling service will carry VoIP service in IEEE 802.16e network.
Our simulation results show that all of the above scheduling types can meet appropriate qualities in accordance with their characteristics and QoS requirements and the bandwidth utilization can also be improved. | en_US |