Link layer support for quality of service on wireless Internet links

We have developed a novel link layer architecture that provides multiple qu ality of service points simultaneously over wireless Internet links. Our ap proach enhances the performance of diverse applications over error-prone li nks. We discuss the performance problems of Internet protocols over wireles s links, presenting as a case study our measurements on a wireless LAN, and argue that it is preferable to handle wireless impairments at the link lay er. We present a simulation study of various link layer enhancements, and t heir impact on TCP-and UDP performance. Our results show that different app roaches are preferable fur each type of application. We thus propose a mult iservice link layer approach that supports multiple link layer mechanisms o ver a single link. Our scheme is transport protocol-independent and customi zable for the underlying wireless link technology. While our approach can b e directly deployed on the existing Internet, it also provides support for future QoS-aware protocols and applications. Our simulation results show th at our approach uniformly improves the performance of both TCP-and UDP appl ications.