The transport control protocol(TCP) does not perform well in a wireless communication system where packets are usually lost due to bit errors, not congestion. This paper summarizes several traditional TCP protocols for wireless links and points out the advantages and disadvantages of each method, and proposes a new approach that adopts the agent of TCP-Acknowledge to improve TCP performance over wireless links, aims at reducing RTT to increase throughput, makes wireless link more robust, and saves bandwidth for uplink services. At last, the paper compares all these methods mentioned in this paper and draws a conclusion.. Index Terms-TCP protocol, wireless link, agent, acknowledgement.