On the enhancement of a differentiated services scheme

Simple integrated media access (SIMA) is a differentiated service scheme based on drop preference bits in every packet. The basic idea of the SIMA is to maximize the exploitation of network resources with a simple control scheme while keeping the ratios of QoS levels offered to different flows unchanged under changeable traffic conditions with a aid of novel charging scheme. This paper examines the potential problems of the SIMA concept and then proposes some possible solutions in order to enhance the service efficiency.