Patent ID: 7904071

Claim:
A wireless two-way radio frequency (RF) data communication device comprising a data packet radio component that selectively reveals its presence in response to RF transmissions, the wireless two-way RF data communication device configured to operate in at least two states comprising: (a) a first state, in which the wireless two-way RF data communication device, (i) receives RF transmissions; (ii) maintains at least one common designation for purposes of filtering RF transmissions received by the wireless two-way RF data communication device; (iii) identifies specific data in a received RF transmission; and (iv) in response to the received RF transmission in which the specific data is identified, (A) transmits a response, (I) if the identified specific data includes data representative of an inquiry as to the presence of one or more wireless two-way RF data communication devices, and (II) if the identified specific data includes data that corresponds to at least one maintained common designation, and (B) does not transmit a response, (I) if the identified specific data does not include data representative of an inquiry as to the presence of one or more wireless two-way RF data communication devices, or (II) if the identified specific data does not correspond to at least one maintained common designation; and (b) a second state mutually exclusive to the first state, in which the wireless two-way RF data communication device, (i) receives RF transmissions; (ii) maintains at least one common designation for purposes of filtering RF transmissions received by the wireless two-way RF data communication device; (iii) identifies specific data in a received RF transmission; and (iv) does not transmit a response to the received RF transmission in which specific data is identified when, (A) the identified specific data includes data representative of an inquiry as to the presence of one or more wireless two-way RF data communication devices, and (B) the identified specific data corresponds to at least one maintained common designation, whereby the wireless two-way RF data communication device selectively communicates its presence in response to RF transmissions.