And how can I ensure that my tags work with Wi-Fi access points?
It depends. A common frequency is not the only requirement for a tag and reader (in this case, the Wi-Fi access point would be acting as the reader). The two must share the same air-interface protocol, which is the “language” that tags and readers use to communicate. For a tag to work with an access point, it must complete a “handshake” that enables communication between the tag and the access point, just as your laptop does. It then needs to be able to communicate using the IEEE 802.11 standard. The best way to ensure that your tags work with Wi-Fi access points is to purchase a system from a reputable company that sells the tags and access points, as well as software to locate the tags on a facility map.
—Mark Roberti, Founder and Editor, RFID Journal