Link layer support for quality of service on wireless Internet links

We have developed a novel link layer architecture that provides multiple quality of service points simultaneously over wireless Internet links. Our approach enhances the performance of diverse applications over error-prone links. We discuss the performance problems of Internet protocols over wireless 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 layer. We present a simulation study of various link layer enhancements, and their impact on TCP and UDP performance. Our results show that different approaches are preferable for each type of application. We thus propose a multiservice link layer approach that supports multiple link layer mechanisms over a single link. Our scheme is transport-protocol-independent and customizable for the underlying wireless link technology. While our approach can be directly deployed an the existing Internet, it also provides support for future QoS-aware protocols and applications. Our simulation results show that our approach uniformly improves the performance of both TCP and UDP applications.