Recently, mobile SCTP (mSCTP) has been proposed as a transport layer approach for supporting mobility. mSCTP is based on the 'multi-homing' feature of Stream Control Transmission Protocol (SCTP), and utilize the functions to dynamically add or delete IP addresses of end points to or from the existing connection in order to support mobility. In this paper, we propose a mechanism to determine when to add or delete an IP address, utilizing the link layer radio signal strength information in order to enhance the performance of mSCTP. We also propose a mechanism for a mobile node to initiate the change of data delivery path based on link layer radio signal strength information. The simulation results show that the performance of proposed transport layer mobility support mechanism is competitive compared to the traditional network layer mobility supporting approach. Especially, when the moving speed of mobile node is fast, it shows better performance than the traditional network layer approach.