Distributed ALE in RFID Middleware

Recently RFID (radio frequency identification) middleware technology attracts great attention due to its competitive business value. Being able to be automatically identified and collect information, RFID systems have been applied to various applications fields. RFID middleware facilitates data communication between automatic identification equipments, like RFID readers, and enterprise applications. ALE (application level events) specification defines that RFID middleware should provide application systems with a group of standard interfaces. And RFID middleware´s basic function is: collecting/filtering. In this paper, we propose the deployment and design for distributed ALE in RFID middleware: ALE is divided into a number of parallel implementation of ALE for RFID middleware; a load balancing mechanism is introduced to work as a coordinator among ALEs. Distributed ALE is not only compatible with EPC global ALE (application level events) specification but also transparent to application systems and equipment management. When the RFID middleware with single ALE connects with too many tags, or its throughput is far beyond the normal throughput, it may delay its response or even break down. To solve this problem, we propose distributed ALE. Our proposed distributed ALE provides a decentralized and steady data processing for RFID middleware, which can enhance the flexibility and availability of the system.