Radio-frequency identification (RFID) has been applied widely in applications such as supply chain visibility, pharmaceutical track and trace, etc. The standards body EPCglobal defines various interfaces in the electronic product code (EPC) network architecture to facilitate the interoperability of different applications. Logical reader is a concept defined in the application level events (ALE) specification to shield applications from knowing the physical device infrastructure. This paper proposes a new approach to the logical reader abstraction, which is defined using spatial zones and implemented by combining mobile, passive RFID with positioning technologies, such as active RFID. This hybrid approach exploits the best benefits of passive and active RFID, while maintaining compatibility with EPC standards for accessing logical readers via ALE. An evaluation of competing approaches is presented. The study shows that this spatial-zone-based design enables fine grain tracking of assets at lower infrastructure cost as compared to existing techniques (e.g., using active RFID only). The study also analyzes the accuracy of the proposed approach using numerical simulation. The results show that it outperforms a widely used chokepoint-based solution under realistic operating conditions. © 2006 IEEE.