Radio communication apparatus
First Claim
1. A radio communication apparatus comprising:
- a sending means for sending a signal for assigning a predetermined number of slots from an antenna to one or more response devices;
a reading means for reading identification information of one or more response devices among response devices receiving the signal, by using a radio communication system in which an response device whose identification information is not yet read, a so-called unread response device, individually selects one slot, and transmits own specific identification information in that slot;
an all slot number counter for counting the number of all slots that are within a slot counting period in a predetermined period after the signal is sent;
an empty slot number counter for counting the number of empty slots whose identification information is not transmitted by an response device, among all slots that are within the slot counting period;
an estimated number calculation means for calculating an estimated number of the unread response devices based on the counted values of the all slot number counter and empty slot number counter, and the number of slots assigned by the signal, at the time when the predetermined period has passed; and
a deciding means for deciding the number of slots assigned by the signal to be sent next, based on the estimated number of unread response devices.
1 Assignment
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Accused Products
Abstract
A radio communication apparatus sends a signal for assigning a predetermined number of slots to one or more response devices. The response devices individually select one slot, and transmit own specific identification information in that slot. The radio communication apparatus has an all slot number counter and an empty slot number counter. The all slot number counter counts the number of all slots received within a slot counting period. The empty slot number counter counts empty slots among those received within the slot counting period. The radio communication apparatus calculates an estimated number of unread response devices whose identification information is not yet read, from the counted values of each counter and the number of slots at the present time. And, based on the estimated number of unread response devices, the radio communication apparatus determines the number of slots to be assigned next.
17 Citations
15 Claims
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1. A radio communication apparatus comprising:
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a sending means for sending a signal for assigning a predetermined number of slots from an antenna to one or more response devices;
a reading means for reading identification information of one or more response devices among response devices receiving the signal, by using a radio communication system in which an response device whose identification information is not yet read, a so-called unread response device, individually selects one slot, and transmits own specific identification information in that slot;
an all slot number counter for counting the number of all slots that are within a slot counting period in a predetermined period after the signal is sent;
an empty slot number counter for counting the number of empty slots whose identification information is not transmitted by an response device, among all slots that are within the slot counting period;
an estimated number calculation means for calculating an estimated number of the unread response devices based on the counted values of the all slot number counter and empty slot number counter, and the number of slots assigned by the signal, at the time when the predetermined period has passed; and
a deciding means for deciding the number of slots assigned by the signal to be sent next, based on the estimated number of unread response devices. - View Dependent Claims (2, 3, 4)
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5. A radio communication apparatus comprising:
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a sending means for sending a signal for assigning a predetermined number of slots from an antenna to one or more response devices;
a reading means for reading identification information of one or more response devices among response devices receiving the signal, by using a radio communication system in which an response device whose identification information is not yet read, a so-called unread response device, individually selects one slot, and transmits own specific identification information in that slot;
a successfully-read slot number counter for counting the number of successfully-read slots for which only one response device transmits identification information, among slots that are within a slot counting period in a predetermined period after the signal is sent;
an expected value calculation means for calculating an expected value when the number of response devices existing in the communication area of the antenna is more than the calculated value of the successfully-read slot number counter;
an estimated number calculation means for calculating an estimated number of the unread response devices at the time when the predetermined period has passed, as a value obtained by subtracting the counted value of the successfully-read slot number counter from the expected value; and
a deciding means for deciding the number of slots assigned by the signal to be sent next, based on the estimated number of unread response devices. - View Dependent Claims (6, 7, 8)
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9. A radio communication apparatus comprising:
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a sending means for sending a signal for assigning a predetermined number of slots from an antenna to one or more response devices;
a reading means for reading identification information of one or more response devices among response devices receiving the signal, by using a radio communication system in which an response device whose identification information is not yet read, a so-called unread response device individually selects one slot, and transmits own specific identification information in that slot;
a correlation data memory which stores data indicating a correlation between the number of unread response devices and the number of slots with which the probability that one unread response device sends the identification information in one slot becomes highest, when said number of unread response devices exist in the communication area of the antenna; and
a retrieving means for searching the correlation data memory by an actual number of the unread response devices at the time before the signal is sent, and reading the number of slots corresponding to the actual number from the correlation data memory, wherein the number of slots to store the correlation data memory is within the range of the number of slots assignable by the signal, and the sending means sends a signal for assigning the number of slots read from the correlation data memory. - View Dependent Claims (10, 11)
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12. A radio communication apparatus comprising:
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a sending means for sending a signal for assigning a predetermined number of slots from an antenna to one or more response devices;
a reading means for reading identification information of one or more response devices among response devices receiving the signal, by using a radio communication system in which an response device whose identification information is not yet read, a so-called unread response device individually selects one slot, and transmits own specific identification information in that slot;
a correlation data memory which stores data indicating a correlation between the number of unread response devices and the number of slots with which the probability that one unread response device sends the identification information in one slot becomes highest, when said number of unread response devices exist in the communication area of the antenna;
a judging means for judging whether the number of unread response devices at the time before the signal is sent is less than a set value;
a variable mode control means for reading the number corresponding to the number of unread response devices from the correlation data memory at the time when the number of unread response devices is judged larger than the set value, and controlling the sending means to send a signal for assigning the number of slots; and
a fixed mode control means for controlling the sending means to send a signal for assigning a predetermined number of slots, when the number of unread units is judged less than the set value;
wherein the number of slots stored in the correlation data memory is within a range of the number of slots assignable by the signal. - View Dependent Claims (13, 14)
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15. A radio communication apparatus comprising:
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a sending means for sending a signal for assigning a predetermined number of slots from an antenna to one or more response devices;
a reading means for reading identification information of one or more response devices among response devices receiving the signal, by using a radio communication system in which an response device whose identification information is not yet read, a so-called unread response device individually selects one slot, and transmits own specific identification information in that slot;
a fixed mode correlation data memory which stores a correlation between the number of unread response devices and a first number of slots, when the number of slots necessary for reading identification information of all unread response devices when the number of slots assigned to the response devices is fixed to a first number of slots, and the number of slots necessary for reading identification information of all unread response devices when the number of slots assigned to the response devices is fixed to a second number of slots large next to the first number of slots, become equal to each other; and
a retrieving means for searching the fixed mode correlation data memory by the number of unread response devices at the time before the signal is sent, and reading the number of slots corresponding to the number of unread response devices from the fixed mode correlation data memory, wherein the number of slots stored in the fixed mode correlation data memory is within a range of the number of slots assignable by the signal, and the sending means repeatedly sends a signal for assigning the number of slots read from the correlation data memory.
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Specification