A mobility management scheme for an all-IP Wireless Metropolitan Area Network (WMAN) is developed in this paper. The proposed scheme is topology-independent and user-independent, in the sense that it does not assume any mobility pattern, delay constraint, or network topology. The key idea is to use a topology-learning algorithm that enables to perform localized mobility management, by efficiently re-selecting a Mobility Anchor Point (MAP) node. The goal of the proposed scheme is to maintain a continues connection under user-dependent delay constraints, while minimizing the signaling cost and packets loss ratio associated with mobility management. This scheme is consistent with the existing mobility management schemes currently used in Mobile IP (MIP) and cellular networks, and it fits into the Hierarchical Mobile IPv6 (HMIPv6) scheme defined in Mobile IPv6 (MIPv6) for integrating mobile terminals with the Internet wired backbone.