Tens of millions of mobile devices and over 20,000 customers and partners rely on our "Always Available" technologies. The products from Sybase iAnywhere include SQL Anywhere, Afaria, OneBridge and RFID Anywhere.

AvantGo, however, is now part of Sybase 365, a new subsidiary of Sybase, Inc., following the acquisition of Mobile 365. Sybase 365 leads the world in the global delivery and settlement of mobile messaging interoperability, and the management and distribution of mobile content.

David: What is an RFID tag?

Martyn: RFID tags come in different formats. The most frequently discussed is the passive tag, which consists of a small microchip, an antenna and a substrate and does not contain a power source.

The microchip stores a unique number -- usually encoded from a number of different pieces of data -- and possibly some other data uniquely identifying the item to which the entire tag will be attached. The microchip typically only holds 64-128 bits of data.

The antenna uses radio waves from the RFID reader to get power and to broadcast the data from the microchip. Finally, the substrate will protect the microchip and antenna and allow the entire tag to be affixed to whatever item it uniquely represents.

For example, a paper sticky label can have the microchip and antenna between two layers of thin paper with an adhesive backing to allow it to be attached to a cardboard box or a small plastic housing can be placed on a keychain.

Passive RFID tags are essentially disposable and used for many asset identification and supply chain applications. This is the type of tag that Wal-Mart and other retailers are requiring as part of their mandates. If an application requires more memory on the tag or further read ranges, an active RFID tag could also be used.

David: What's the difference between active and passive RFID tags?

Martyn: Active tags contain a power source, usually a battery, possibly solar, or some other power source; which means they typically have a larger read range and more memory since the power source gives more power to the radio waves.

They communicate to specialized readers using different, often proprietary protocols and data. In addition, many of the active tags we see coming to market today also incorporate other sensors such as temperature or light sensors, and can communicate the sensory data along with the tag identification data.

David: Doesn't that mean that RFID is radiating at a very long distance? I thought RFID was a very short range device?

Martyn: When you configure RFID readers, you have control over the power used by the antennas to give you control over the size of the "read zone." Some systems require larger read zones like loading dock doors -- you want to make sure you don't miss any items coming/going.

Some need small read zones, for example, access control systems, which require the person to hold an ID badge close to the reader without worrying about picking up other tags.