Cart-Based Visibility System

A method for use with a building comprising at least first second, and third rooms, the method comprising the steps of:

• providing a cart, the cart having at least three wheels, the cart having a first first loop antenna and a radio transceiver, the first loop antenna communicatively coupled with the radio transceiver, the radio transceiver operating at a frequency lower than 1 megahertz, the first first loop antenna having an area greater than 0.2 square meters;
• placing the cart in the first room;
• while the cart is in the first room, communicating by means of the first loop antenna with at least first, second, and third tags, each of the first, second, and third tags being at least five feet from the cart, the communication with the first, second, and third tags achieved without reorienting the first loop antenna, the communication with the first, second, and third tags each yielding an identification of each of the first, second, and third tags;
• moving the cart to the second room;
• while the cart is in the second room, communicating by means of the first loop antenna with at least fourth, fifth, and sixth tags, each of the fourth, fifth, and sixth tags being at least five feet from the cart, the communication with the fourth, fifth, and sixth tags achieved without reorienting the first loop antenna, the communication with the fourth, fifth, and sixth tags each yielding an identification of each of the fourth, fifth, and sixth tags;
• moving the cart to the third room;
• while the cart is in the third room, communicating by means of the first loop antenna with at least seventh, eighth, and ninth tags, each of the seventh, eighth, and ninth tags being at least five feet from the cart, the communication with the seventh, eighth, and ninth tags achieved without reorienting the first loop antenna, the communication with the seventh, eighth, and ninth tags each yielding an identification of each of the seventh, eighth, and ninth tags.