This paper reveals a new view on mobility management based on the relations between communication users. Communication users with close relation contact each other more frequently than other users, which dominate majority of total communication traffic. The performance of these users impact the overall communication system severely. We design a new mobility management mechanism, “push-and-cache”, to provide a special location lookup service for user group that have close relations to improve system performance. Through this new mechanism we fulfill that location service is moving with user mobility. An analytical model is developed to evaluate the performance of the proposed mobility management system. Results show that the push-and-cache system outperforms Signaling System 7 (SS7) mobility management system in terms of location lookup delay and signaling transport cost.