The purpose of the research project is to design simple, efficient, and robust mechanisms to  improve the performance of Transmission Control Protocol (TCP) in mixed wired/wireless and ad hoc communication networks. The basic approach is to  study how the soon-to-be-standardized Selective  Acknowledgment (SACK) feature of TCP, together with knowledge of the statistical behavior of wireless links, can be used to decouple the error recovery and flow control functions of TCP by distinguishing between transient and persistent packet loss. The network will be modeled within a stochastic framework, guided and validated by computer simulation. Rigorous mathematical techniques, as well as extensive computer simulation, will be employed to design and analyze the  performance of each mechanism. In order to accurately  evaluate the performance of the mechanisms, they will  be implemented experimentally under a wide variety  of real-world conditions using channel emulation hardware. The education plan can be summarized as one of utilizing  the vast resources at the University of Michigan,  participating in several initiatives in curriculum  development, involving undergraduate students in research,  and developing Web-based Matlab modules.