Method of addressing messages and communications system
First Claim
1. A method of establishing wireless communications between an interrogator and wireless identification devices, the method comprising utilizing a tree search technique to establish communications, without collision, between the interrogator and individual ones of the multiple wireless identification devices, the method including using a search tree having multiple nodes respectively representing sub-groups of the multiple wireless identification devices, the method further comprising, for a node, transmitting a command, using the interrogator, requesting that devices within the subgroup represented by the node respond, determining with the interrogator if a collision occurred in response to the command and, if not, repeating the command at the same node.
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Accused Products
Abstract
A method of establishing wireless communications between an interrogator and individual ones of multiple wireless identification devices, the method comprising utilizing a tree search method to attempt to identify individual ones of the multiple wireless identification devices so as to be able to perform communications, without collision, between the interrogator and individual ones of the multiple wireless identification devices, a search tree being defined for the tree search method, the tree having multiple nodes respectively representing subgroups of the multiple wireless identification devices, wherein the interrogator transmits a command at a node, requesting that devices within the subgroup represented by the node respond, wherein the interrogator determines if a collision occurs in response to the command and, if not, repeats the command at the same node. An interrogator configured to transmit a command at a node, requesting that devices within the subgroup represented by the node respond, the interrogator further being configured to determine if a collision occurs in response to the command and, if not, to repeat the command at the same node.
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Citations
129 Claims
- 1. A method of establishing wireless communications between an interrogator and wireless identification devices, the method comprising utilizing a tree search technique to establish communications, without collision, between the interrogator and individual ones of the multiple wireless identification devices, the method including using a search tree having multiple nodes respectively representing sub-groups of the multiple wireless identification devices, the method further comprising, for a node, transmitting a command, using the interrogator, requesting that devices within the subgroup represented by the node respond, determining with the interrogator if a collision occurred in response to the command and, if not, repeating the command at the same node.
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7. A method of addressing messages from an interrogator to a selected one or more of a number of communications devices, the method comprising:
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establishing for respective devices unique identification numbers;
causing the devices to select random values, wherein respective devices choose random values independently of random values selected by the other devices;
transmitting a communication, from the interrogator, requesting devices having random values within a first specified group of random values to respond;
receiving the communication at multiple devices, devices receiving the communication respectively determining if the random value chosen by the device falls within the first specified group and, if so, sending a reply to the interrogator; and
determining using the interrogator if a collision occurred between devices that sent a reply and, if so, creating a second specified group smaller than the first specified group; and
, if not, again transmitting a communication requesting devices having random values within the first specified group of random values to respond. - View Dependent Claims (8, 9, 10)
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11. A method of addressing messages from a transponder to a selected one or more of a number of communications devices, the method comprising:
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establishing unique identification numbers for respective devices;
causing the devices to select random values, wherein respective devices choose random values independently of random values selected by the other devices;
transmitting a communication from the transponder requesting devices having random values within a specified group of a plurality of possible groups of random values to respond, the plurality of possible groups being organized in a binary tree defined by a plurality of nodes at respective levels, the specified group being defined as being at one of the nodes;
receiving the communication at multiple devices, devices receiving the communication respectively determining if the random value chosen by the device falls within the specified group and, if so, sending a reply to the transponder; and
, if not, not sending a reply; and
determining using the transponder if a collision occurred between devices that sent a reply and, if so, creating a new, smaller, specified group by descending in the tree; and
, if not, transmitting a communication at the same node. - View Dependent Claims (12, 13)
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14. A method of addressing messages from an interrogator to a selected one or more of a number of RFID devices, the method comprising:
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establishing for respective devices unique identification numbers;
causing the devices to select random values, wherein respective devices choose random values independently of random values selected by the other devices;
transmitting a command using the interrogator requesting devices having random values within a specified group of a plurality of possible groups of random values to respond, the specified group being equal to or less than the entire set of random values, the plurality of possible groups being organized in a binary tree defined by a plurality of nodes at respective levels;
receiving the command at multiple RFID devices, RFID devices receiving the command respectively determining if their chosen random values fall within the specified group and, only if so, sending a reply to the interrogator, wherein sending a reply to the interrogator comprises transmitting the unique identification number of the device sending the reply;
determining using the interrogator if a collision occurred between devices that sent a reply and, if so, creating a new, smaller, specified group using a different level of the tree, the interrogator transmitting a command requesting devices having random values within the new specified group of random values to respond; and
, if not, the interrogator re-transmitting a command requesting devices having random values within the first mentioned specified group of random values to respond; and
if a reply without collision is received from a device, the interrogator subsequently sending a command individually addressed to that device. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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- 21. A communications system comprising an interrogator, and a plurality of wireless identification devices configured to communicate with the interrogator using RF, the interrogator being configured to employ tree searching to attempt to identify individual ones of the multiple wireless identification devices, so as to be able to perform communications without collision between the interrogator and individual ones of the multiple wireless identification devices, the interrogator being configured to follow a search tree, the tree having multiple nodes respectively representing subgroups of the multiple wireless identification devices, the interrogator being configured to transmit a command at a node, requesting that devices within the subgroup represented by the node respond, the interrogator further being configured to determine if a collision occurs in response to the command and, if not, to repeat the command at the same node.
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27. A system comprising:
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an interrogator;
a number of communications devices capable of wireless communications with the interrogator;
means for establishing for respective devices unique identification numbers respectively having the first predetermined number of bits;
means for causing the devices to select random values, wherein respective devices choose random values independently of random values selected by the other devices;
means for causing the interrogator to transmit a command requesting devices having random values within a specified group of random values to respond;
means for causing devices receiving the command to determine if their chosen random values fall within the specified group and, if so, to send a reply to the interrogator; and
means for causing the interrogator to determine if a collision occurred between devices that sent a reply and, if so, to create a new, smaller, specified group; and
, if not, transmit a command requesting devices having random values within the same specified group of random values to respond. - View Dependent Claims (28, 29, 30)
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31. A system comprising:
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an interrogator configured to communicate to a selected one or more of a number of communications devices; and
a plurality of communications devices;
the devices being configured to select random values, wherein respective devices choose random values independently of random values selected by the other devices;
the interrogator being configured to transmit a command requesting devices having random values within a specified group of a plurality of possible groups of random values to respond, the specified group being less than the entire set of random values, the plurality of possible groups being organized in a binary tree defined by a plurality of nodes at respective levels, the specified group being defined as being at one of the nodes;
devices receiving the command being configured to respectively determine if their chosen random values fall within the specified group and, only if so, send a reply to the interrogator, wherein sending a reply to the interrogator comprises transmitting the unique identification number of the device sending the reply;
the interrogator being configured to determine if a collision occurred between devices that sent a reply and, if so, create a new, smaller, specified group using a different level of the tree, the interrogator being configured to transmit a command requesting devices having random values within the new specified group of random values to respond; and
, if not, the interrogator being configured to re-transmit a command requesting devices having random values within the first mentioned specified group of random values to respond. - View Dependent Claims (32, 33, 34)
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35. A system comprising:
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an interrogator configured to communicate to a selected one or more of a number of RFID devices;
a plurality of RFID devices, respective devices being configured to store a unique identification number, respective devices being further configured to store a random value;
the interrogator being configured to transmit a command requesting devices having random values within a specified group of a plurality of possible groups of random values to respond, the plurality of possible groups being organized in a binary tree defined by a plurality of nodes at respective levels, the specified group being defined as being at one of the nodes;
devices receiving the command respectively being configured to determine if their chosen random values fall within the specified group and, if so, send a reply to the interrogator; and
, if not, not send a reply; and
the interrogator being configured to determine if a collision occurred between devices that sent a reply and, if so, to create a new, smaller, specified group by descending in the tree; and
, if not, to transmit a command at the same node. - View Dependent Claims (36, 37, 38)
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39. A method implemented in a radio frequency identification (RFID) system, the method comprising:
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transmitting a radio frequency wireless signal from at least one interrogator to cause a plurality of RFID tags to individually generate random numbers;
transmitting a first wireless request from the at least one interrogator to request RFID tags having generated random numbers in a first subset of random numbers to reply;
if a response to the first request, transmitted from one RFID tag of the plurality of RFID tags, is obtained at the at least one interrogator, repeating the first request; and
if no response to the first request is obtained at the at least one interrogator, transmitting a second request from the at least one interrogator to request RFID tags having generated random numbers in a second subset of random numbers to reply. - View Dependent Claims (40, 41, 42, 43, 44, 45)
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46. A radio frequency identification (RFID) reader, comprising:
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a transmitter to transmit at least a first portion of an identifier to request a first response from an RFID device that has at least a first portion of an identification code equal to the at least first portion of the identifier;
a receiver to receive the first response from the device; and
a processing circuit coupled to the transmitter and receiver to implement an algorithm to detect at least one from among potentially multiple RFID devices, wherein in accordance with the algorithm the processing circuit is to perform collision detection on the first response and, in response to detecting no collision, to retransmit, via the transmitter, the at least first portion of the identifier and to request a second response thereto. - View Dependent Claims (47, 48, 49, 50, 51, 52, 53, 54, 55)
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56. A system, comprising:
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an RFID target device to receive at least a first portion of an identifier, to compare the at least first portion of the identifier to at least a first portion of an identification code of the target device, and to communicate a reply value if the at least first portion of the identifier is equal to the at least first portion of the identification code; and
an RFID initiating device to initiate communication with one or more RFID target devices, the initiating device to transmit a first request including a first command and first information, to receive a first response to the first request from each of one or more RFID target devices that has a respective identification code selected by the first information, to perform collision detection on the first response, and to transmit a second request including a retransmission of at least the first command and the first information responsive to detecting no collision. - View Dependent Claims (57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69)
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70. A radio frequency identification (RFID) device, comprising:
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a memory to store a first identifier;
a receiver coupled to an antenna to receive a transmission of a first set of bits from a reader in accordance with an algorithm to enable the reader to determine the first identifier;
processing circuitry to compare the first set of bits to a first set of bits of an identification code of RFID device; and
a modulating circuit to modulate an RF field produced by the reader to communicate a second set of bits to the reader if the first set of bits is equal to the first set of bits of the identification code, wherein the first identifier comprises the second set of bits, and wherein in accordance with the algorithm the receiver is to further receive a retransmission of at least the first set of bits from the reader if the reader receives the second set of bits without collision. - View Dependent Claims (71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82)
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83. A radio frequency identification (RFID) method, comprising:
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transmitting a first wireless radio frequency (RF) signal from an RFID reader, the first RF signal specifying a first set of bits to request a set of RFID devices having the first set of bits to identify themselves, wherein each of the RFID devices generates a random value to select a time slot to identify themselves;
receiving at the RFID reader a response to the first RF signal from at least a first RFID device in a first time slot, wherein the first RFID device selects the first time slot to transmit the response in accordance with a first random value generated by the first RFID device and the response including an identifier of the first RFID device;
determining the identifier of the first RFID device from the response received in the RFID reader;
transmitting a second wireless RF signal from the RFID reader, the second RF signal to prevent the first RFID device from responding when the first RF signal is repeated; and
retransmitting the first RF signal from the RFID reader. - View Dependent Claims (84, 85, 86, 87, 88, 89, 90)
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91. A radio frequency identification (RFID) method, comprising:
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transmitting a first wireless command from an RFID reader, the first command including a first set of bits to address a set of RFID devices identified by the first set of bits, the first command to request the RFID devices to respond with identifiers of the RFID devices;
determining an identifier of at least a first RFID device from at least one reply to the first command;
after the determining of the identifier, transmitting a second wireless command from the RFID reader, the second wireless command to silence the first RFID device for a third wireless command; and
transmitting the third wireless command from the RFID reader, the third command including the first set of bits to address a set of RFID devices identified by the first set of bits. - View Dependent Claims (92, 93, 94, 95, 96, 97, 98, 99)
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100. A radio frequency identification method, comprising:
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transmitting at least a first portion of an identifier to request a first response from a radio frequency device that has at least a first portion of an identification code equal to the at least first portion of the identifier;
receiving the first response from the radio frequency device;
executing an algorithm to identify at least one from among potentially multiple radio frequency devices, wherein in accordance with the algorithm a processing circuit is to perform collision detection on the first response and, if no collision is detected, retransmitting the at least first portion of the identifier to request a second response;
receiving the second response;
determining an identifier of the radio frequency device using at least the first response;
associating an owner with the identifier of the radio frequency device; and
debiting an account held by the owner. - View Dependent Claims (101, 102, 103, 104, 105, 106, 107, 108, 109)
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110. A method implemented in a radio frequency identification apparatus, the method comprising:
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transmitting a first wireless request from at least one interrogating apparatus to request one or more radio frequency devices having random numbers in a first subset of random numbers to reply;
if a response to the first request, transmitted from one radio frequency device of the plurality of radio frequency devices, is obtained at the at least one interrogating apparatus, repeating the first request; and
if no response to the first request is obtained at the at least one interrogating apparatus, transmitting a second request from the at least one interrogating apparatus to request radio frequency devices having generated random numbers in a second subset of random numbers to reply;
receiving an identifier of one radio frequency device of the plurality of radio frequency devices;
associating the identifier of the one radio frequency device of the plurality of radio frequency devices with an account; and
debiting the account. - View Dependent Claims (111, 112, 113, 114, 115, 116)
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117. A radio frequency identification method, comprising:
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transmitting at least a first portion of an identifier to request a first response from a radio frequency device that has at least a first portion of an identification code equal to the at least first portion of the identifier;
receiving the first response from the radio frequency device;
executing an algorithm to detect at least one from among potentially multiple radio frequency devices, wherein in accordance with the algorithm a processing circuit is to perform collision detection on the first response and, after detecting no collision, retransmitting the at least first portion of the identifier to request a second response;
receiving the second response and determining an identifier of the radio frequency device using the first response;
associating the identifier of the radio frequency device with a financial account; and
debiting the account for the value of at least one of (i) a good;
(ii) a service; and
/or (iii) a roadway toll, provided to a possessor of the radio frequency device. - View Dependent Claims (118, 119, 120, 121, 122)
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123. A method of conducting a transaction using radio frequency identification apparatus, comprising:
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operating interrogation apparatus;
transmitting via the interrogation apparatus at least a first portion of an identifier to request a first response from a radio frequency device that has at least a first portion of an identification code equal to the at least first portion of the identifier;
receiving the first response from the radio frequency device;
executing an algorithm to identify at least one from among potentially multiple radio frequency devices, wherein in accordance with the algorithm a processing circuit is to perform collision detection on the first response and, if no collision is detected, retransmitting the at least first portion of the identifier from the interrogation apparatus to request a second response;
receiving the second response;
determining an identifier of the radio frequency device using at least the first response; and
debiting an account associated with the identifier. - View Dependent Claims (124, 125, 126, 127, 128, 129)
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Specification