Method of Addressing Messages and Communications System
2 Assignments
0 Petitions
Accused Products
Abstract
A method of establishing wireless communications between an interrogator and individual ones of multiple wireless identification devices, the method comprising combining tree search and Aloha methods to establish communications between the interrogator and individual ones of the multiple wireless identification devices without collision. A system comprising an interrogator, and a plurality of wireless identification devices configured to communicate with the interrogator in a wireless fashion, the respective wireless identification devices having a unique identification number, the interrogator being configured to employ tree search and Aloha techniques to determine the unique identification numbers of the different wireless identification devices so as to be able to establish communications between the interrogator and individual ones of the multiple wireless identification devices without collision by multiple wireless identification devices attempting to respond to the interrogator at the same time.
-
Citations
65 Claims
-
1-40. -40. (canceled)
-
41. A method for performing radio frequency communications, the method comprising:
-
(A) generating by a first radio frequency identification (RFID) tag a first random number;
(B) transmitting by an interrogator a first request for a first response from the first RFID tag if the first random number is within a first subgroup of possible random numbers;
(C) receiving by the first RFID tag the first request;
(D) communicating by the first RFID tag the first response when the first random number is within the first subgroup, the communicating being performed at a time based upon a second random number;
(E) redefining the first subgroup as a subset of a previous first subgroup and repeating steps B-E when a collision occurs; and
(F) redefining the first subgroup as another subgroup of possible random numbers when the first response is received by the interrogator without collision, the first response including one or more random numbers generated by the first RFID tag. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50, 51)
-
-
52. A method for a radio frequency identification (RFID) tag to perform wireless communications, the method comprising:
-
receiving a request, the request including a subset of possible random numbers;
determining whether a first random number generated by the RFID tag is within the subset; and
communicating a response to the request at a time based at least in part on a second random number generated by the RFID tag. - View Dependent Claims (53, 54, 55, 56, 57, 58, 59)
-
-
60. A method for an interrogator to poll a plurality of radio frequency identification (RFID) tags, the method comprising:
-
causing each of the plurality of RFID tags to generate one or more random numbers, each random number being generated by respective ones of the plurality of RFID tags independently of other ones of the plurality of RFID tags;
defining a first subgroup of a plurality of subgroups of possible random numbers;
transmitting a request to the plurality of RFID tags for identified RFID tags having generated a random number within the first subgroup to respond;
repeatedly redefining the first subgroup to include fewer possible random numbers and transmitting a new request for identified RFID tags having a random number within the first subgroup to respond until receiving a response without a collision or receiving no response; and
repeatedly picking a different subgroup and repeating the transmitting, the receiving, and the repeatedly redefining when a valid response or no response is received until the plurality of RFID tags have been identified, the valid response including at least one random number. - View Dependent Claims (61, 62, 63, 64, 65)
-
Specification