Transmission control protocol （TCP） has been designed and tuned as a reliable transfer protocol forwired links. However

it incurs end-to-end performance degradation in mobileenvironments. Recentyears

many protocols have been proposed to enhance the performance of TCP in mobile environments. Although these methods simulate better than original TCP

but they either need an intermediary （such as the base station） to modify TCP or cannot perform well in the situations where both high bit errorrates and disconnections happen. In this article

we propose a protocol named adaptive TCP

which is a combination of TCP HACK （Header Checksum Option） and Freeze-TCP mechanisms but both have been modified to make them work more efficiently. By using the adaptive TCP

we can get a true end-to- end TCP and offer quality of service for the performance of TCP in mobile environments where both high bit error rates and disconnections occur.