Patent ID: 8422398

Claim:
A system for radio frequency communication between Readers and Tags, the system comprising; (a) at least one tag Reader; (b) a plurality of Tags deployed in a region in which at least some of the Tags are in radio communication with said tag Reader, at least some tags are in radio communication with other Tags in said plurality of Tags, and each tag is associated with a unique tag ID; and (c) a Media Access Control protocol according to which: said tag Reader is configured to send and receive radio communications to and from at least some of said plurality of Tags, said plurality of Tags are configured to send and receive radio communications to and from said tag Reader and other Tags in said plurality of Tags, wherein said plurality of Tags are divided into groups based on at least part of the unique ID of each tag, and wherein said tag Reader is configured to initiate a relay session after a rate of direct replies from said plurality of tags falls below a predetermined threshold, wherein initiation of the relay session causes at least one of the Tags to relay radio communications to or from another Tag that has not received the radio communication from said tag Reader.