Wireless systems have evolved to successfully penetrate the world of personal communications, where virtually all people can talk as needed on-demand with a feature rich and flexible set of alternatives. This world of people talking is now being complemented with a wireless world of all things “talking” – in other words, all things are becoming wireless. As these new systems continue to evolve to meet their best-fit applications in the enterprise, matching each one’s unique characteristics to the application is not always clear to the prospective end user or even to a providing system integrator.

Passive RFID system solutions are well known for their strengths and weaknesses in various tagging applications from access control to the supply chain. Active RFID/RTLS offers many more application opportunities for labor free automatic identification, counting, locating, sensing and protecting of assets; however, active RFID solutions today are being addressed using a handful of different system architectures. The mapping of best-fit characteristics for each is critical to achieving a workable system with the necessary reliability and at the lowest cost. What follows is a best-fit application analysis of the various active RFID system architecture alternatives for enterprise tagging solutions.

The Foundation
Enterprise RFID systems can generally be categorized as either “passive” or “active,” with passive tags using the received signal for power and active tags using an embedded battery for power. Passive deployments typically occur in the high-frequency and ultra-high-frequency (HF/UHF) radio bands with applications such as the tracking of goods in the supply chain. They typically have low cost tags with higher cost infrastructures. Passive tag transmissions are also limited to the power of reflective (or backscatter) signaling and, as such, only transmit reliably in inches up to a few feet. The systems are characterized as fitting best in manual oriented auto-ID applications such as barcoding and today’s proximity-based access control cards. In addition, passive solutions use fixed portal infrastructures designed to automatically ID goods in the supply chain such as pallets, crates and cartons moving through the controlled portal. On the other hand, active deployments are characterized by having the power to transmit over greater ranges with added flexibility in infrastructure design. Although active tags are typically more expensive than passive the infrastructures are less costly, and active deployments fit the need for automatic identification where no human involvement is needed or desired. The applications include asset tracking, personnel management, shipping container tracking and local vehicle management systems, all of which use a variety of frequencies.

Download pdf A Guide to Best-Fit Applications for Active RFID System Alternatives