In Wireless Personal Area Networks (WPANs), the Zigbee protocol/IEEE 802.15.4 standard is a protocol specification for low range, less cost and low power systems. The Zigbee network is usually constructed using cluster trees for the purpose of performing data delivery among nodes and for power saving. Here the data delivery failures occur due to node mobility. In order to handle node movements so as to increase data delivery we use mobility-robust tree construction technique with clustering mechanism. In this paper we propose an E-MRZT (Extended MRZT) algorithm. We collect information about regularity of mobility patterns and by using this history, perform data delivery. We employ a clustering mechanism in our network to obtain a set of cluster trees; each with a specific mobility pattern. The entire setup is developed and simulated by using NS2 network simulator. The result is that we obtain mobility-robust tree with a considerable increase in data delivery
