Radio frequency identification system with write broadcast capability

A radio frequency tag, comprising:

• a tag antenna for receiving a radio frequency write signal broadcasted from a base station, the radio frequency signal containing sent data and and a sent address and not being associated in advance with said tag;
• a tag memory having a tag data location identified by the sent address and containing old data;
• a tag logic having an active state and an initialize state, a Select Command placing the tag in the active state if the tag meets a select condition and an Unselect Command placing the tag in the initialize state if the tag meets an unselect condition;
• and
• a tag receiver for receiving the radio frequency write signal from the tag antenna, the tag automatically writing the sent data to the tag data location identified by the sent address if the tag is in the active state and the tag not writing the sent data to the tag data location identified by the sent address if the tag is in the initialize state.

A radio frequency tag, comprising:

• a tag antenna for receiving a broadcasted radio frequency write signal from a base station, the radio frequency write signal identifying no particular destination tag and containing one or more sent data and one or more sent addresses corresponding to the sent data;
• a tag receiver for decoding each of the sent data and the sent addresses from the radio frequency write signal;
• a tag memory having one or more tag data locations, each tag data location having a respective tag data address;
• a tag receiver for receiving the radio frequency signal from the tag antenna;
• and
• a tag logic having an active state and an initialize state, a Select Command placing the tag in the active state if the tag meets a select condition and an Unselect Command placing the tag in the initialize state if the tag meets an unselect condition, the tag automatically writing each of the sent data into the tag data location with the tag data address identified by the respective sent address if the tag is in the active state and the tag not writing any of the sent data if the tag is in the initialize state, without the tag first sending a tag identifier to the base station.

A base station for communicating with radio frequency tags in a field of the base station, each of the tags having a tag memory, the base station comprising:

• a signal generator that develops a signal containing sent data and a sent address and identifying no particular destination tag;
• a base station transmitter that encodes the signal on the carrier to create an encoded signal;
• and
• a base station antenna that transmits the encoded signal to two or more tags in the field causing the tags to simultaneously write the sent data into their tag memories at a tag data location identified by the sent address without the tags first sending tag identifiers to the base station,
• the base station listening for a response from one or more tags, a response from one or more tags causing the base station transmitter to retransmit the encoded signal.

A base station for communicating with radio frequency tags in a field of the base station, each of the tags having a tag memory, the tag memory having a tag data location identified by a tag data address, the base station comprising:

• a computer that develops a select command and a write broadcast signal, the write broadcast signal being associated with no particular destination tag or tags and containing a write broadcast command, sent data and a sent address;
• a base station transmitter that encodes the select command on a radio frequency carrier to create a select signal and encodes the write broadcast signal on the radio frequency carrier to create a write signal;
• and
• a base station antenna that transmits the select signal to all the tags in the field to select a subgroup of the tags, and subsequently transmits the write signal to simultaneously write the sent data to the tag data location having a tag data address corresponding to the sent address in the selected subgroup of the tags.

A radio frequency tagging system, comprising:

• radio frequency tags, each tag having a tag logic and a tag antenna and each tag further having one or more tag data locations associated with a tag data address;
• a base station having a computer, a transmitter, and a base antenna;
• and
• a process executed by the computer that causes a radio frequency write broadcast signal associated with no particular destination tag(s) to be sent through the transmitter and base antenna into a field, the write broadcast signal having two or more sent data and a sent address corresponding to each of the sent data, tags in the field receiving the write broadcast signal through the tag antenna thereof and the tag logic of the tags in the field causing the sent data to be simultaneously written to the tag data locations of the tags that have a tag data address matching the respective sent address.

A radio frequency tag comprising:

• a tag antenna means for receiving a radio frequency write broadcast signal from a base station, the radio frequency write broadcast signal containing sent data and a sent address and being associated with no particular destination tag(s);
• a tag memory means having a tag data location identified by the sent address and containing old data;
• a tag receiver means for receiving the radio frequency write broadcast signal from the tag antenna and writing the sent data to the tag data location identified by the sent address without first sending a unique tag identifier to the base station;
• and
• a tag transmitter means for sending a response to the base station when the sent data is different than the old data in the tag data location identified by the sent address.

A base station for communicating simultaneously with a plurality of radio frequency tags in a field of the base station, each of the tags having a tag memory, the base station comprising:

• a signal generator means for developing a signal containing sent data and a sent address;
• a base station receiver;
• a base station transmitter means for encoding the signal with the sent data and the sent address on a radio frequency carrier to create an encoded carrier;
• and
• a base station antenna means for transmitting the encoded carrier simultaneously to the plurality of tags in the field,
• the plurality of tags simultaneously writing the sent data into their tag memories at a tag data location identified by the sent address without first sending a unique tag identifier to the base station.

A radio frequency tag, comprising:

• a tag antenna for receiving a broadcasted radio frequency write signal from a base station, the radio frequency write signal having sent data and a sent address and identifying no particular destination tag(s), and the tag antenna further for communicating one or more responses to the base station;
• a tag memory having a tag data location identified by the sent address and containing old data;
• a tag logic having an active state and an initialize state, a Select Command placing the tag in the active state if the tag meets a select condition and an Unselect Command placing the tag in the initialize state if the tag meets an unselect condition, where the tag in the active state that receives an Unselect Command and does not meet the unselect condition communicates one of the responses through the tag antenna to the base station;
• a tag receiver for receiving the radio frequency write signal from the tag antenna, the tag writing the sent data to the tag data location identified by the sent address if the tag is in the active state and the tag not writing the sent data to the tag data location identified by the sent address if the tag is in the initialize state.

A base station for communicating simultaneously with a plurality of radio frequency tags in a field of the base station, each of the tags having a tag memory, the base station comprising:

• a signal generator that develops a signal containing sent data and a sent address;
• a base station transmitter that encodes the signal onto a carrier to create an encoded signal;
• and
• a base station antenna that
• transmits the encoded signal to the plurality of tags in the field for causing the tags to simultaneously write the sent data into their tag memories at a tag data location identified by the sent address without each of the tags first sending a unique tag identifier to the base station,
• sends a group unselect command to the tags that unselects tags that have the sent data in their respective tag memories, and
• listens for a response from one or more tags.

A base station for communicating with a plurality of radio frequency tags in a field of the base station, each of the tags having a tag memory, the tag memory having one or more tag data locations and each of the tag data locations having a tag data address, the base station comprising:

• a computer that develops an unselect command and a write broadcast signal, the write broadcast signal being associated with no particular destination tag(s) and containing a write broadcast command, sent data and a sent address;
• a base station transmitter that encodes the unselect command on a radio frequency carrier to create an unselect signal and encodes the write broadcast signal on the radio frequency carrier to create a write signal;
• and
• a base station antenna that transmits the unselect signal to all the tags in the field to unselect a subgroup of the tags, and subsequently transmits the write signal to all tags in the field to simultaneously write the sent data into the tags not in the unselected subgroup to the tag data location having the tag data address corresponding to the sent address.

A method performed by a base station, comprising the steps of:

• a. selecting radio frequency tags in a field of tags by issuing one or more select and zero or more unselect commands, the selected tags becoming active and the not selected tags remaining initialized;
• b. issuing an unselect command that causes unselected tags to become initialized if the value in each of the tag data locations with tag data addresses corresponding to a sent address are equal to sent data, and to remain active and respond if the value in any of tag data locations does not equal the sent data;
• and
• c. issuing a write broadcast command associated with no particular destination tag or tags if any response is received to step b.

A method performed by a base station comprising the steps of:

• a. selecting zero or more of the radio frequency tags in a field of tags by issuing one or more select and zero or more unselect commands, the selected tags becoming active and the not selected tags remaining initialized;
• b. issuing an unselect command that causes unselected tags to become initialized if the value in each of the tag data locations with tag data addresses corresponding to a sent address are equal to sent data, and to remain active and respond if the value in any of tag data locations does not equal the sent data;
• and
• c. issuing a write broadcast command associated with no particular destination tag or tags if any response is received to step b.