Improved dynamic weighted cell scheduling algorithm based on earliest deadline first scheme for various traffics of ATM switch

We propose new Dynamic Weighted cell scheduling algorithm using Earliest Deadline First (DWEDF) scheme based on cell in an ATM (Asynchronous Transfer Mode) network. Also, we analyze the performances of proposed scheme and conventional method through simulation. Proposed algorithm could support the QoS (Quality of Service) of various traffics such as VBR (Variable Bitrate), CBR (Constant Bitrate), ABR (Available Bitrate) and UBR (Unspecified Bitrate) in an ATM multiplexer and switch. Also, DWEDF algorithm could dynamically schedule cells and could support performance required in the outgoing link according to the QoS parameters. Moreover, proposed algorithm could support ABR and UBR service more efficiently due to the `total bandwidth oriented round cycle' property, and suppress incoming cells which violate the QoS parameter by setting CLP (Cell-Loss Priority)-flag in DWEDF_CLP method or discarding cell in DWEDF_BLOCK method. Thus, due to reliable ABR and UBR service as well as congestion avoidance capability, proposed DWEDF algorithm has good performance over conventional DWRR scheme. Furthermore, deadline based cell transmission algorithm in DWEDF algorithm minimizes cell delay and requires less temporary buffer size. Thus, DWEDF algorithm provides reliable support for the QoS of various traffics in an ATM multiplexer and switch.