Clustering methods for radio-frequency-identifier networks
First Claim
1. A method for predicting a subset C from a set SC, comprising all multi-RFID-tag-readers in a multi-RFID-tag-reader network, wherein the subset C detects an event E with an increased accuracy in comparison to the set SC, the method comprising:
- partitioning the RFID-tag-readers in the set SC for collision avoidance;
receiving threshold parameters including an index start;
sorting the set SC in descending order based on the correlation of each RFID-tag-reader in the set SC with the event E, where the index start is set to one of the multi-RFID-tag-readers of the set SC with a highest correlation with event E;
initializing the set C to contain the one RFID-tag-reader of the set SC with the index start;
identifying candidate RFID-tag-readers in SC that meet a criterion defined by the threshold parameters,repeatedly relaxing the threshold parameters,adding an identified candidate RFID-tag-reader to the subset C; and
removing the identified candidate RFID-tag-reader from the set SC until a cost computed for subset C exceeds a threshold cost.
2 Assignments
0 Petitions
Accused Products
Abstract
Methods and systems of the present invention are directed to clustering RFID-tag readers of a multi-RFID-tag-reader network in order to obtain a set of RFID-tag readers with high probability of detecting an event, but with low probability of collisions and with an acceptable cost. The cost may be determined by any of numerous cost functions of the RFID-tag readers in the set of RFID-tag readers, and may represent a cost in power, long-term reliability, and other such metrics that may be applied to an RFID-tag network.
-
Citations
13 Claims
-
1. A method for predicting a subset C from a set SC, comprising all multi-RFID-tag-readers in a multi-RFID-tag-reader network, wherein the subset C detects an event E with an increased accuracy in comparison to the set SC, the method comprising:
-
partitioning the RFID-tag-readers in the set SC for collision avoidance; receiving threshold parameters including an index start; sorting the set SC in descending order based on the correlation of each RFID-tag-reader in the set SC with the event E, where the index start is set to one of the multi-RFID-tag-readers of the set SC with a highest correlation with event E; initializing the set C to contain the one RFID-tag-reader of the set SC with the index start; identifying candidate RFID-tag-readers in SC that meet a criterion defined by the threshold parameters, repeatedly relaxing the threshold parameters, adding an identified candidate RFID-tag-reader to the subset C; and removing the identified candidate RFID-tag-reader from the set SC until a cost computed for subset C exceeds a threshold cost. - View Dependent Claims (2, 3, 4, 5, 6, 7, 13)
-
-
8. A method for predicting a subset C from a set SC, comprising all multi-RFID-tag-readers in a multi-RFID-tag-reader network, wherein the subset C detects the event E with an increased accuracy in comparison to the set SC, the method comprising:
-
partitioning the RFID-tag-readers in the set SC for collision avoidance; computing a cross-correlation matrix R for the RFID-tag-readers in the set SC with respect to the event E; computing a diagonalized cross-correlation matrix R′
by;
R′
=TRT−
1, wherein T is a diagonalizing matrix for R;computing a set of virtual scanners by matrix multiplication of T and S;
TS, wherein S is a vector of scanners;sorting the set of virtual scanners by corresponding eigenvalues in R−
1;and truncating the sorted set of virtual scanners to form the subset C. - View Dependent Claims (9, 10, 11, 12)
-
Specification