The standardized IEEE 802.15.4/ZigBee protocol stack offers great potentials for ubiquitous and pervasive computing. One of its open and ambiguous issues is how to build a synchronized cluster-tree network, which sometimes suffer from beacon collisions. The purpose of this paper is to overcome this problem by proposing a group-mobility predictive location-based beacon scheduling scheme. In many exiting applications, group movement of sensor nodes is one of the features. Group mobility model is used to represent the relationship among nodes. Utilizing the current locations and group mobility model, future locations of cluster headers are predicted. Based on the predictive locations, beacon frames are scheduled to avoid collisions. According to the simulation results, the proposed scheme provides a better network performance than the conventional approaches.