Modeling and simulation can help to validate and evaluate the performance of wireless sensor networks (WSNs) within specific applications. In order to resolve the issue of the restriction on node mobility in existing Zigbee WSN simulation models, this paper proposes a Zigbee compliant new simulation model using the OPNET simulator. Based on the Zigbee MAC layer model in OPNET Modeler, we develop a network layer model and propose an improved AODV routing algorithm to support node mobility, both of which are compatible with Zigbee protocols. We further present in details the structure of the network layer process model and the implementation procedures of its kernel functions. Comprehensive performance comparisons are performed between the proposed model and the Zigbee model in OPNET standard libraries. In order to evaluate the effectiveness of the proposed model in the aspect of node mobility support, time intervals between route failure occurrence and route recovery are measured as ...