Mobility management is a very important function of mobile communication in all-IP radio heterogeneous network. In order to achieve an efficient mobility management, with low delay and low beacon overhead, a micromobile stream control transmission protocol (mmSCTP) scheme was proposed. This scheme reasonably utilizes SCTP features and elaborately designs execution-steps for vertical handoff. Moreover, it provides fast locating for idle mobile node when a session is initiated by the correspondent node. The analytical and simulation results show that the proposed scheme is effective in supporting fast vertical handoff and effective location management.