COMMUNICATION SYSTEM FOR COMMUNICATING WITH TAGS

A communication system for identifying, locating, tracking and communicating for other purposes with large numbers of tags in a time and energy efficient manner. The tags are associated with items located in a communication region that is interrogated by an interrogator on a one-to-many basis using broadcast commands, on a one-to-one basis using directed commands or on a combination basis using both methods. Identification occurs through organized transmission and reception of signals between the tags and the interrogator. A batch collection protocol uses a combined one-to-many and one-to-one communication system that effectively resolves communication contentions. The batch collection protocol employs a plurality of collection periods which communicate with large or unknown numbers of portable tags.