Wireless tag reader, wireless tag system, computer readable medium and wireless communication method

A wireless tag system comprising a plurality of wireless tags and a wireless tag reader communicating with the wireless tags,

• each of the wireless tags including:
• a memory configured to store tag information piece and a bloom filter generated from the tag information piece by using a bloom filter algorithm;
• and
• a responder configured to, in response to a read request signal sent from the wireless tag reader, code the bloom filter stored in the memory by using a certain coding scheme to generate a bloom filter signal, and transmits the generated bloom filter signal to the wireless tag reader, and
• the wireless tag reader including:
• a transmitter configured to transmit a read request signal simultaneously to the wireless tags to request the wireless tags to read out the bloom filters;
• a receiver configured to receive bloom filter signals simultaneously from the wireless tags to acquire a colliding bloom filter signal;
• a decoder configured to decode the colliding bloom filter signal to acquire a composite bloom filter which is equivalent to logic operation OR on the bloom filters;
• a data storage configured to store tag information pieces;
• and
• a filter verifier configured to verify each of tag information pieces in the data storage with the composite bloom filter to detect tag information pieces for which a verification result is positive or negative.

A computer readable medium storing a computer program for causing a computer, capable of communicating with a plurality of wireless tags each of which retains tag information piece and a bloom filter generated from the tag information piece on the basis of a bloom filter algorithm to execute instructions, to perform steps of:

• transmitting a read request signal simultaneously to the wireless tags to request the wireless tags to read out the bloom filters;
• receiving bloom filter signals simultaneously from the wireless tags to acquire a colliding bloom filter signal;
• decoding the colliding bloom filter signal to acquire a composite bloom filter which is equivalent to logic operation OR on the bloom filters;
• and
• verifying previously given tag information pieces with the composite bloom filter to detect tag information pieces for which a verification result is positive or negative.

A wireless communication method used to communicate with a plurality of wireless tags each of which retains tag information piece and a bloom filter generated from the tag information piece on the basis of a bloom filter algorithm, the wireless communication method comprising:

• transmitting a read request signal simultaneously to the wireless tags;
• receiving bloom filter signals simultaneously from the wireless tags to acquire a colliding bloom filter signal;
• decoding the colliding bloom filter signal to acquire a composite bloom filter which is equivalent to logic operation OR on the bloom filters;
• and
• verifying previously given tag information pieces with the composite bloom filter to detect tag information pieces for which a verification result is positive or negative.