Method of addressing messages and communications system
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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 combining tree search and Aloha methods to establish communications between the interrogator and individual ones of the multiple wireless identification devices without collision. A system comprising an interrogator, and a plurality of wireless identification devices configured to communicate with the interrogator in a wireless fashion, the respective wireless identification devices having a unique identification number, the interrogator being configured to employ tree search and Aloha techniques to determine the unique identification numbers of the different wireless identification devices so as to be able to establish communications between the interrogator and individual ones of the multiple wireless identification devices without collision by multiple wireless identification devices attempting to respond to the interrogator at the same time.
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Citations
80 Claims
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1-40. -40. (canceled)
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41. 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 a first predetermined number of bits to be used as unique identification numbers, and establishing for respective devices unique identification numbers respectively having the first predetermined number of bits;
establishing a second predetermined number of bits to be used for random values;
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 from the interrogator requesting devices having random values within a specified group of random values to respond, the specified group being less than or equal to the entire set of random values;
receiving the command at multiple devices, the devices receiving the command respectively determining if the random value chosen by the command falls within the specified group and, if so, sending a reply to the interrogator within a randomly selected time slot of a number of slots; and
, if not, not sending a reply; and
determining with the interrogator if a collision occurred between devices that sent a reply and, if so, creating a new, smaller, specified group. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49)
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50. 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 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 from the interrogator a command requesting devices having random values within a specified group of random values to respond, the specified group being less than or equal to the entire set of random values;
receiving the command at multiple devices, the devices receiving the command respectively determining if the random value chosen by the device falls within the specified group and, if so, sending a reply to the interrogator within a randomly selected time slot of a number of slots; and
, if not, not sending a reply; and
determining using the interrogator if a collision occurred between devices that sent a reply and, if so, creating a new, smaller, specified group. - View Dependent Claims (51, 52, 53)
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54. 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 respectively having a first predetermined number of bits;
establishing a second predetermined number of bits to be used for random values;
causing the devices to select random values, wherein respective devices choose random values independently of random values selected by the other devices;
transmitting from the interrogator a command requesting devices having random values within a specified group of random values to respond, the specified group being less than or equal to the entire set of random values;
receiving the command at multiple devices, the devices receiving the command respectively determining if the random values chosen by the device falls within the specified group and, if so, sending a reply to the interrogator within a randomly selected time slot of a number of possible time slots, in accordance with an Aloha technique; and
, if not, not sending a reply, wherein sending a reply to the interrogator comprises transmitting both the random value of the device sending the reply and the unique identification number of the device sending the reply, and wherein the time slot randomly selected by a device is selected using a random number different from the random value of that device;
determining with the interrogator if a collision occurred between devices that sent a reply and, if so, creating a new, smaller, specified group; 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 (55, 56)
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57. 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 respectively having a first predetermined number of bits;
establishing a second predetermined number of bits to be used for random values;
causing the devices to select random values, wherein respective devices choose random values independently of random values selected by the other devices;
transmitting from the interrogator a command requesting devices having random values within a specified group of random values to respond, the specified group being less than or equal to the entire set of random values;
receiving the command at multiple devices, the devices receiving the command respectively determining if the random values chosen by the device falls within the specified group and, if so, sending a reply to the interrogator within a randomly selected time slot of a number of possible time slots, in accordance with an Aloha technique; and
, if not, not sending a reply, wherein sending a reply to the interrogator comprises transmitting both the random value of the device sending the reply and the unique identification number of the device sending the reply, and wherein the time slot randomly selected by a device is selected using a random number different from the random value of that device;
determining with the interrogator if a collision occurred between devices that sent a reply and, if so, creating a new, smaller, specified group; and
if a reply without collision is received from a device, the interrogator subsequently sending a command individually addressed to that device;
wherein the number of possible slots varies from one specified group to another. - View Dependent Claims (58, 59)
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- 60. A communications system comprising an interrogator, and a plurality of wireless identification devices configured to communicate with the interrogator in a wireless fashion, the respective wireless identification devices having a unique identification number, the interrogator being configured to employ tree search and Aloha techniques to determine the unique identification numbers of the different wireless identification devices so as to be able to establish communications between the interrogator and individual ones of the multiple wireless identification devices without collision by multiple wireless identification devices attempting to respond to the interrogator at the same time.
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63. A system comprising:
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an interrogator;
a number of communications devices capable of wireless communications with the interrogator;
means for establishing a first predetermined number of bits to be used as unique identification numbers, and for establishing for respective devices unique identification numbers respectively having the first predetermined number of bits;
means for establishing a second predetermined number of bits to be used for random values;
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, the specified group being less than or equal to the entire set of random values;
means for causing devices receiving the command to determine if their chosen random values fall within the specified group and, if so, send a reply to the interrogator within a randomly selected time slot of a number of slots; and
, if not, not send a reply; and
means for causing the interrogator to determine if a collision occurred between devices that sent a reply and, if so, create a new, smaller, specified group. - View Dependent Claims (64, 65, 66, 67, 68, 69, 70, 71)
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72. A system comprising:
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an interrogator configured to communicate to a selected one or more of a number of communications devices;
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 random values to respond, the specified group being less than or equal to the entire set of random values;
devices receiving the command being configured to respectively determine if their chosen random values fall within the specified group and, if so, send a reply to the interrogator within a randomly selected time slot of a number of slots; 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, create a new, smaller, specified group. - View Dependent Claims (73)
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74. A system comprising:
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an interrogator configured to communicate to a selected one or more of a number of communications devices;
a plurality of communications devices, respective devices being configured to store unique identification numbers respectively having a first predetermined number of bits, respective devices being further configured to store a second predetermined number of bits to be used for random values, respective devices being configured to select 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 random values to respond, the specified group being less than or equal to the entire set of random values;
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 within a randomly selected time slot of a number of possible time slots, in accordance with an Aloha technique; and
, if not, not send a reply, wherein sending a reply to the interrogator comprises transmitting both the random value of the device sending the reply and the unique identification number of the device sending the reply, and wherein the time slot randomly selected by a device is selected using a random number different from the random value of that device;
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; and
the interrogator being configured to send a command individually addressed to a device after communicating with a device without a collision;
wherein the number of possible slots varies from one specified group to another. - View Dependent Claims (75, 76)
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77. A system comprising:
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an interrogator configured to communicate to a selected one or more of a number of communications devices;
a plurality of communications devices, respective devices being configured to store unique identification numbers respectively having a first predetermined number of bits, respective devices being further configured to respectively store a second predetermined number of bits to be used for respective random values, respective devices being configured to select random values independently of random values selected by the other devices;
the interrogator being configured to define a group of random values, the group being a subset of all possible values the devices could select, and to transmit a command requesting devices having random values corresponding to any of the random values in the defined group to respond;
devices respectively being configured to, in response to receiving the command, determine if their chosen random values fall within the defined group and, if so, send a reply to the interrogator within a randomly selected time slot of a number of possible time slots, in accordance with Aloha; and
, if not, not send a reply, wherein sending a reply to the interrogator comprises transmitting both the random value of the device sending the reply and the unique identification number of the device sending the reply, wherein the time slot randomly selected by a device is selected using a random number different from the random value of that device, and wherein the number of possible slots varies from one specified group to another; and
the interrogator being configured to determine if a collision occurred between devices that sent a reply and, if so, to define a new, smaller, specified group. - View Dependent Claims (78, 79)
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80. A system comprising:
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an interrogator configured to communicate to a selected one or more of a number of communications devices;
a plurality of communications devices, respective devices being configured to store unique identification numbers, respective devices being further configured to respectively store respective random values, respective devices being configured to select random values independently of random values selected by the other devices;
the interrogator being configured to define a group of random values, the group being a subset of all possible values the devices could select, and to transmit a command requesting devices having random values corresponding to any of the random values in the defined group to respond;
devices respectively being configured to, in response to receiving the command, determine if their chosen random values fall within the defined group and, if so, send a reply to the interrogator within a randomly selected time slot of a number of possible time slots, in accordance with Aloha; and
, if not, not send a reply, wherein the number of possible time slots varies from one specified group to another; and
the interrogator being configured to determine if a collision occurred between devices that sent a reply and, if so, to define a new, smaller, specified group.
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Specification