Scheduling algorithms for quality of service of various types of traffic in wireless ATM networks.

摘要

To satisfy the QoS of various traffic types in ATM network, we proposed two scheduling algorithms for efficient transmission in the wired and wireless ATM networks.; The Multiple Weighted Earliest Deadline First (MWEDF) algorithm is proposed to support ABR (Available Bit Rate) traffic sources efficiently as well as VBR (Variable Bit Rate) and CBR (Constant Bit Rate) traffic sources. This algorithm schedules each input VCC (Virtual Circuit Channel) link based on the earliest deadline first mechanism. We simulated this algorithm and compared the performance with the conventional Dynamic Weighted Round Robin (DWRR) algorithm. In the analysis, we showed that the mean cell delay is less than the DWRR scheme and the maximum buffer size is decreased.; Then we extended the MWEDF algorithm to the Wireless MWEDF algorithm to support the various traffic sources efficiently in wireless ATM networks. We designed Wireless MWEDF on the basis of the Earliest Deadline First algorithm to minimize the delay time and reduce the buffer size in wireless ATM networks. Then we simulated this algorithm and compared the performance with the conventional Priority Regulated Allocation Delay Oriented Scheduling (PRADOS) algorithm. In the analysis we showed that the W-MWEDF algorithm provides more reliable and efficient support for CBR, VBR, ABR and UBR (Unspecified Bit Rate) traffic than the PRADOS algorithm.; To reduce the overhead of the physical layer in the wireless ATM network, we designed the packing algorithm. The packing algorithm is used to reallocate the scheduling table according to the link. And then, the Frame Header and the MPDU (MAC Protocol Data Unit) Headers are inserted to be transmitted.; To develop these algorithms, we studied the Tenet approach, the characteristics of real-time communication and conventional algorithms such as Weighted Round Robin (WRR), Dynamic Weighted Round Robin (DWRR), and the PRADOS algorithms. Conventional schemes do not support the wired and wireless ATM traffics effectively. This investigation led us to develop the MWEDF algorithm, the W-MWEDF algorithm and the packing algorithm, which provide better support for the design of real-time communication and wireless ATM networks.