Building Smart RFID Networks

By Hersh Bhargava

Converting RFID Data Into Information
The volume of RFID data makes it imperative to handle that data very carefully, at the proper time and the right place in the RFID network. The main difference between data and information is that information has a business context associated with it and is valuable to certain processes or applications with minimal interpretation.

Consider the example of receiving RFID-tagged goods at a receiving dock door. As an RFID interrogator receives inventory, many RFID read events are generated. Raw RFID data consists of individual RFID reads, stored as separate events in the repository. If all these EPC reads were collected and compared with an advance shipping notice (ASN), that would translate to more meaningful information. These multiple RFID reads could be stored as a single business event, called "receiving," which would then be more relevant to the business. This business event, "receiving," would be transmitted to a receiving application, such as ePOD, to send out notifications to the sender of those tagged goods.

In a supply chain dealing with perishables, a business event called "stale" would be very helpful, compared with just a raw RFID read. As an EPC was read in the supply chain, the RFID network could evaluate the freshness of the product using master data. If the EPC were read past the expiration date, then a business event called "stale" would be stored in the RFID network. Anytime this EPC was read again in the supply chain, the RFID network would look for a stale event and stop the product from going further without any additional evaluation.

A single physical read may lead to multiple business events. To turn RFID data into meaningful information, one needs to convert and authenticate it into events using business rules, store business events (such as "receiving" or "stale") and route them to the right application.

Event Routing
An RFID network may generate high volumes of streaming RFID reads, while subscriber applications may receive RFID reads in two ways:
• Every EPC (or auto-ID) read is sent to all subscribers of an RFID network.
• Subscribers receive only processed events they have requested.

Comparing this with Internet Protocol (IP) networks, the first strategy is similar to a hub, where all IP packets are broadcast to every device connected to that hub. In an RFID network, this strategy creates unnecessary traffic and puts the burden on the applications to sieve out the "interesting" events. In a smart RFID network, raw events are pre-processed and converted to business events before being passed to the subscriber applications. As information flows in a company's RFID network, it may change its form and content.