KR20220083331A - System, apparatus, method and program for estimating number of tag using operating period and message - Google Patents

Abstract

A backscatter communication system for estimating the number of tags using an operation section and a message according to the present invention includes: a reader device for transmitting a communication request message in the request section; Any one of a query command and a query repeat command including a first arbitrary slot counter parameter at each start end of a plurality of slots included in a plurality of estimated frames included in the number of tags estimation section based on the communication request message and a packet a helper device that broadcasts; and setting a slot counter based on the first arbitrary slot counter parameter in a first slot among the plurality of slots, and reflecting or absorbing the packet based on whether the slot counter is a preset reference slot counter, and the reader device a plurality of tag devices for detecting the tag information, wherein the reader device includes an end terminal of the plurality of slots based on a detection result of detecting the tag information from the plurality of tag devices during each of the plurality of slots Each one of a tag information detection message, a tag information collision message, and a tag information non-detection message is transmitted to the helper device, and the helper device sends the tag information detection message, the tag information collision message, and the tag information non-detection message. The number of tags of the plurality of tag devices may be determined based on .

Description

A backscatter communication system, method and program for estimating the number of tags using an operating period and a message {System, apparatus, method and program for estimating number of tag using operating period and message}

The present invention relates to a backscatter communication system, method, and program for estimating the number of tags using an operation section and a message, and more particularly, whether a reader device normally detects tag information of a plurality of tag devices for which a slot counter is set The present invention relates to a backscatter communication system, method, and program for estimating the number of tags by using an operation period and a message capable of determining the number of tags of a plurality of tag devices based on a message transmitted from a reader device to a helper device according to the present invention.

The Wi-Fi backscatter system consists of three elements: a Wi-Fi AP (Wi-Fi Helper; access point), a Wi-Fi Reader (a terminal such as a mobile phone), and a tag (Wi-Fi backscatter Tag; RF power supply). A Wi-Fi AP and a Wi-Fi reader are one of the Wi-Fi devices, and can transmit and receive Wi-Fi packets.

The tag is a battery-free tag with RF-powered function, and unlike other elements, it is not a Wi-Fi device, so it cannot transmit Wi-Fi packets and cannot read incoming Wi-Fi packets. . However, it is possible for the tag to transmit the information it wants to transmit to the reader through backscattering (backscattering) using Wi-Fi packets. do.

In general, in order for the reader to detect tag information, the reader requests tag information from the AP, and the AP that receives the request continuously transmits Wi-Fi packets, and after the tag receives power from the AP's Wi-Fi packet, It reflects or absorbs the Wi-Fi packet transmitted from the AP according to each bit in its own tag information, and the reader checks the change in Channel State Information (CSI) or Received Signal Strength Indication to tag detect information.

The tag can check the signal sent by the reader using the difference in amplitude with respect to the power of the signal sent by the reader or the time when the power of the signal is sensed.

Such a Wi-Fi backscatter system uses a slot counter parameter to allow a reader device to detect individual tag information in an environment in which a plurality of tag devices exist. Conventionally, the slot counter parameter is used as a fixed arbitrary value or By using the value changed by the administrator, there is a problem in that the slot counter parameter optimized according to the network condition in real time cannot be used.

The present invention provides an operating period in which the number of tags of a plurality of tag devices can be determined based on a message transmitted from a reader device to a helper device according to whether the reader device normally detects tag information from a plurality of tag devices for which a slot counter is set; It is possible to provide a backscatter communication system for estimating the number of tags using a message.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned may be understood by the following description, and will be more clearly understood by the examples of the present invention. It will also be readily apparent that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the appended claims.

A backscatter communication system for estimating the number of tags using an operation section and a message according to the present invention includes: a reader device for transmitting a communication request message in the request section; Any one of a query command and a query repeat command including a first arbitrary slot counter parameter at each start end of a plurality of slots included in a plurality of estimated frames included in the number of tags estimation section based on the communication request message and a packet a helper device that broadcasts; and setting a slot counter based on the first arbitrary slot counter parameter in a first slot among the plurality of slots, and reflecting or absorbing the packet based on whether the slot counter is a preset reference slot counter, and the reader device a plurality of tag devices for detecting the tag information, wherein the reader device includes an end terminal of the plurality of slots based on a detection result of detecting the tag information from the plurality of tag devices during each of the plurality of slots Each one of a tag information detection message, a tag information collision message, and a tag information non-detection message is transmitted to the helper device, and the helper device sends the tag information detection message, the tag information collision message, and the tag information non-detection message. The number of tags of the plurality of tag devices may be determined based on .

Preferably, upon receiving the query command, the plurality of tag devices sets a slot counter range using the first arbitrary slot counter parameter, and sets one of the spare slot counters among the spare slot counters included in the slot counter range. can be set as the slot counter, and when the query repeat command is received, the slot counter is decremented and set.

Preferably, if the slot counter is the preset reference slot counter, the plurality of tag devices may reflect or absorb the packet so that the reader device detects the tag information.

Preferably, when the reader device detects the tag information from any one of the plurality of tag devices, the reader device transmits the tag information detection message to the helper device, and the tag device exceeds one of the plurality of tag devices When the tag information is sensed, the tag information collision message may be transmitted to the helper device, and if the tag information is not detected, the tag information non-detection message may be transmitted to the helper device.

Preferably, the helper device is configured to receive a first message number of the tag information detection message received during any one of the plurality of estimated frames, a second message reception number of the tag information collision message, and the tag information not detected. The number of third message receptions of the message may be calculated.

Preferably, the helper device includes an estimated number of first message receptions of the tag information detection message estimated to be received during any one of the plurality of estimated frames, an estimated second message reception number of the tag information collision message, and The estimated number of third message receptions of the tag information undetected message may be calculated.

Preferably, the helper device includes: the first message reception number, the second message reception number, the third message reception number, the first message estimated reception number, the second message estimated reception number, and the third message estimated reception number The estimated number of tags of any one of the plurality of estimated frames may be estimated based on the number.

Preferably, the helper device may determine an average between the estimated number of tags in each of the plurality of estimated frames as the number of tags of the plurality of tag devices.

A backscatter communication method for estimating the number of tags using an operation section and a message according to the present invention comprises: transmitting, by a reader device, a communication request message in the request section; Any one of a query command and a query repeat command, wherein the helper device includes a first arbitrary slot counter parameter at each start end of a plurality of slots included in a plurality of estimation frames included in the tag number estimation section based on the communication request message broadcasting a packet with one; a plurality of tag devices set a slot counter based on the first arbitrary slot counter parameter in a first slot among the plurality of slots, and reflect or absorb the packet based on whether the slot counter is a preset reference slot counter transmitting tag information to the reader device; A tag information detection message, a tag information collision message, and no tag information detection at each end of the plurality of slots based on a detection result of the reader device detecting the tag information from the plurality of tag devices during each of the plurality of slots sending any one of the messages to the helper device; and determining, by the helper device, the number of tags of the plurality of tag devices based on the tag information detection message, the tag information collision message, and the tag information non-detection message.

The computer program according to the present invention may be stored in a computer-readable recording medium so as to perform a backscatter communication method of estimating the number of tags using an operating section and a message in combination with a computer as hardware.

According to the present invention, the number of tags of the plurality of tag devices is determined based on a message transmitted from the reader device to the helper device according to whether the reader device normally detects tag information from the plurality of tag devices for which the slot counter is set. It is possible to accurately estimate the number of the plurality of tag devices in the state.

1 is a diagram illustrating a configuration of a backscatter communication system for estimating the number of tags using an operation section and a message according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating the configuration of an operating section used by a backscatter communication system for estimating the number of tags using an operating section and a message according to an embodiment of the present invention.
3 is a diagram for explaining an estimation algorithm used by a backscatter communication system for estimating the number of tags using an operation section and a message according to an embodiment of the present invention.

Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include various modifications, equivalents, and/or alternatives of the embodiments of the present invention. In connection with the description of the drawings, like reference numerals may be used for like elements.

In this document, expressions such as "have", "may have", "includes", or "may include" indicate the presence of a corresponding characteristic (eg, a numerical value, function, operation, or component such as a part). and does not exclude the presence of additional features.

In this document, expressions such as “A or B”, “at least one of A or/and B”, or “one or more of A or/and B” may include all possible combinations of the items listed together. . For example, "A or B", "at least one of A and B", or "at least one of A or B" means (1) includes at least one A, (2) includes at least one B; Or (3) it may refer to all cases including both at least one A and at least one B.

Expressions such as "first", "second", "first", or "second" used in this document can modify various elements, regardless of order and/or importance, and It is used only to distinguish it from other components, and does not limit the components. For example, the first user equipment and the second user equipment may represent different user equipment regardless of order or importance. For example, without departing from the scope of the rights described in this document, a first component may be referred to as a second component, and similarly, the second component may also be renamed as a first component.

One component (eg, a first component) is "coupled with/to" or "connected" to another component (eg, a second component) (eg, operatively or communicatively) When referring to "connected to", it should be understood that the certain element may be directly connected to the other element or may be connected through another element (eg, a third element). On the other hand, when it is said that a component (eg, a first component) is "directly connected" or "directly connected" to another component (eg, a second component), the component and the It may be understood that other components (eg, a third component) do not exist between other components.

The expression “configured to (or configured to)” as used in this document, depending on the context, for example, “suitable for”, “having the capacity to )", "designed to", "adapted to", "made to", or "capable of" . The term "configured (or set up to)" may not necessarily mean only "specifically designed to" in hardware. Instead, in some circumstances, the expression “a device configured to” may mean that the device is “capable of” with other devices or parts. For example, the phrase “a processor configured (or configured to perform) A, B, and C” refers to a dedicated processor (eg, an embedded processor) for performing the operations, or by executing one or more software programs stored in memory. , may mean a generic-purpose processor (eg, a CPU or an application processor) capable of performing corresponding operations.

Terms used in this document are only used to describe specific embodiments, and may not be intended to limit the scope of other embodiments. The singular expression may include the plural expression unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meanings as commonly understood by one of ordinary skill in the art described in this document. Among the terms used in this document, terms defined in a general dictionary may be interpreted with the same or similar meaning as the meaning in the context of the related art, and unless explicitly defined in this document, have an ideal or excessively formal meaning. not interpreted In some cases, even terms defined in this document cannot be construed to exclude embodiments of this document.

1 is a diagram illustrating a configuration of a backscatter communication system for estimating the number of tags using an operation section and a message according to an embodiment of the present invention.

Referring to FIG. 1 , a backscatter communication system for estimating the number of tags using an operation section and a message according to the present invention may include a helper device 100 , a reader device 200 , and a plurality of tag devices 300 . have.

When the reader device 200 requests tag information of the plurality of tag devices 300 from the helper device 100 , the plurality of tag devices 300 reflect or absorb packets of the helper device so that the reader device 200 transmits the tag. The information may be detected, and the reader device 200 may transmit a message indicating the detection result of the tag information to the helper device 100 and the tag device 200 .

The helper device 100 is configured to transmit and receive wireless signals such as Wi-Fi, and the reader device 200 may receive signals from the helper device 100 and the tag device 300 . For example, the reader device 200 may be a communication device such as a mobile terminal and a smart phone, and the helper device 100 may be a Wi-Fi router.

The plurality of tag devices 300 are components capable of absorbing or reflecting the signal of the helper device 100 , and preferably include an antenna to absorb or reflect the signal of the helper device 100 .

The plurality of tag devices 300 may level-modulate the signal of the helper device 100 to 0 or 1 through intermittent reflection using an antenna and transmit it to the reader device 200 . For example, the plurality of tag devices 300 may transmit signals in the form of 00, 01, 10, and 11 when modulating with 4 levels.

In this case, intermittent reflection may be possible by adjusting the amount of reflection of the antennas included in the plurality of tag devices 300 . That is, the reader device 200 detects the tag information through channel state information or Received Signal Strength Indication (RSSI) that is changed due to the signal of the helper device 100 reflected by the tag device 300 . .

FIG. 2 is a diagram illustrating the configuration of an operating section used by a backscatter communication system for estimating the number of tags using an operating section and a message according to an embodiment of the present invention.

2 , the backscatter communication system for estimating the number of tags using an operation period and a message according to the present invention includes a request period (RP), a tag number estimation period (TEP), and communication An operation period including a Communication Period (CP) and a Termination Period (TP) may be used.

In the request section, communication of the backscatter communication system for estimating the number of tags using the operation section and the message according to the present invention can be started.

Thereafter, when a communication request message that does not include the number of tags is received, the helper device 100 may perform an estimation period for the number of tags.

Conversely, when a communication request message including the number of tags is received, the helper device 100 may omit the tag count estimation section and perform the communication section.

The number of tags estimation section may include a plurality of estimation frames, and each of the plurality of estimation frames may include a plurality of slots.

In addition, the communication section may include a plurality of communication frames, and each of the plurality of communication frames may include a plurality of slots.

During each of the plurality of slots described above, command transmission/reception and message transmission/reception may be performed between the helper device 100 , the reader device 200 , and each of the plurality of tag devices 300 .

Specifically, during the tag count estimation section, the helper device 100 may determine the number of tags of the plurality of tag devices 300 .

During the communication period, the reader device 200 may detect tag information from the plurality of tag devices 300 .

Finally, since there are no packets to be transmitted/received and tag information to be detected in the end section, communication of the backscatter communication system for estimating the number of tags using the operation section and message according to the present invention may be terminated.

Hereinafter, a process for estimating and determining the number of tags by the backscatter communication system for estimating the number of tags using an operation section and a message according to an embodiment of the present invention will be described.

3 is a diagram for explaining an estimation algorithm used by a backscatter communication system for estimating the number of tags using an operation section and a message according to an embodiment of the present invention.

Referring further to FIG. 3 , the reader device 200 may transmit a communication request message REQ that does not include the number of tags in the request section to the helper device 100 .

At this time, the helper device 100 includes a first random slot counter parameter (Q _tep ) at each start end of a plurality of slots included in a plurality of estimation frames included in the tag number estimation section based on the communication request message. Any one of a query command and a query repeat command and a packet can be broadcast.

Specifically, when the helper device 100 receives a communication request message that does not include the number of tags, the helper device 100 may start an estimation period for the number of tags.

First, when the tag number estimation section starts, the helper device 100 determines the frame index (i_tep) of the plurality of estimated frames, the number of estimated frames with the estimated number of tags (n _frame ), and the estimated tag of the estimated frame in which the frame index is i_tep You can initialize the number (n _{tag,i_tep} ), the average between the estimated number of tags (n _{avg_tag} ), and the number of tags (n _tag ). Here, initialization may mean setting each variable to “0”.

In addition, the helper device 100 determines the number of first message receptions (n _{ACK,i_tep} ) of the tag information detection message received during the estimation frame in which the frame index is i_tep among the plurality of estimation frames, and the number of reception of the second message of the tag information collision message. (n _{COL,i_tep} ) and the third message reception count (n _{EMP,i_tep} ) of the tag information non-detection message may be set to “0”.

The helper device 100 may sequentially broadcast a query command including a first arbitrary slot counter parameter and a packet at a start end of a first slot among a plurality of slots included in a plurality of estimation frames.

Also, the helper device 100 may sequentially broadcast a query repetition command including a first arbitrary slot counter parameter and a packet at a start end from a second slot among a plurality of slots included in a plurality of estimation frames.

The plurality of tag devices 300 may set a slot counter based on a first arbitrary slot counter parameter of the query command when receiving the query command at the beginning of the slot.

Specifically, the plurality of tag devices 300 may set the slot counter range by using the first arbitrary slot counter parameter, and set any one spare slot counter among the spare slot counters included in the slot counter range as the slot counter. have.

-1“으로 설정하고, 슬롯 카운터 범위에 포함된 예비 슬롯 카운터 중 어느 하나의 예비 슬롯 카운터를 슬롯 카운터로 설정할 수 있다. 여기서, 슬롯 카운터는 0이상의 정수일 수 있다.For example, the plurality of tag devices 300 set the slot counter range from “0 to” based on the first arbitrary slot counter parameter “Q _tep ”.

-1", and any one of the spare slot counters included in the slot counter range can be set as the slot counter. Here, the slot counter may be an integer greater than or equal to 0.

Meanwhile, the plurality of tag devices 300 may set by decrementing the set slot counter when a query repeat command is received.

Specifically, the plurality of tag devices 300 may set the set slot counter by decrementing “1” when a query repeat command is received.

Thereafter, if the slot counter is a preset reference slot counter, the plurality of tag devices 300 may reflect or absorb the packet following the query command or the query repeat command.

Here, the preset reference slot counter may be “0”.

The plurality of tag devices 300 may reflect or absorb packets so that the reader device 200 detects tag information.

Conversely, if the slot counter is not a preset reference slot counter, the plurality of tag devices 300 may not reflect or absorb a packet received following the query command.

The reader device 200 generates a tag information detection message (ACK) and a tag information collision message (COL) at each end of the plurality of slots based on whether the tag information of the plurality of tag devices 300 is detected during each of the plurality of slots. and a tag information non-detection message (EMP) may be transmitted to the helper device 100 .

Specifically, when the reader device 200 detects tag information of any one of the plurality of tag devices 300 , the reader device 200 sends a tag information detection message to the helper device 100 and the tag device ( 300) can be sent.

In addition, when the reader device 200 detects tag information from more than one of the plurality of tag devices 300 , it sends a tag information conflict message to the helper device 100 and the tag device ( 300) can be sent.

Also, when tag information is not detected, the reader device 200 may transmit a tag information non-detection message to the helper device 100 and the tag device 300 to which the corresponding tag information has been transmitted.

When the helper device 100 receives any one of a tag information detection message, a tag information collision message, and a tag information non-detection message at each end of the plurality of frames during any one of the plurality of estimated frames, the received message In response, any one of the number of first messages received, the number of second messages received, and the number of third messages received may be updated.

Meanwhile, the plurality of tag devices 300 may end operations upon receiving a tag information detection message from the reader device 200 . Also, the plurality of tag devices 300 may wait for operation upon receiving a tag information collision message from the reader device 200 . The plurality of tag devices 300 may not perform an additional operation upon receiving the tag information non-detection message from the reader device 200 .

Thereafter, the helper device 100 determines the estimated number of first message receptions (E[n _{ACK,i_tep} ]) of the tag information detection message estimated to be received during any one of the plurality of estimation frames, the tag information collision message. The estimated number of second message receptions (E[n _{COL,i_tep} ]) and the estimated third message reception number (E[n _{EMP,i_tep} ]) of the tag information non-detection message may be calculated.

In this case, the helper device 100 may calculate the estimated number of first message receptions, the estimated second message reception number, and the estimated third message reception number using Equations 1 to 4 below.

는 n개의 태그 장치 중에서 k개의 태그 장치가 추정 프레임 내의 슬롯을 차지할 확률(태그 정보 메시지를 송수신할 확률)이고,

는 하나의 태그 장치가 추정 프레임 내의 임의의 슬롯을 차지할 확률이고,

은 추정 프레임 크기(=

)이고,

는 태그 정보 감지 메시지의 제1 메시지 추정 수신 수 이고,

는 태그 정보 충돌 메시지의 제2 메시지 추정 수신 수 이고,

는 태그 정보 미감지 메시지의 제3 메시지 추정 수신 수일 수 있다.here,

is the probability that k tag devices among n tag devices occupy a slot in the estimated frame (probability of transmitting and receiving a tag information message),

is the probability that one tag device occupies any slot in the estimated frame,

is the estimated frame size (=

)ego,

is the estimated number of first message receptions of the tag information detection message,

is the estimated number of second message receptions of the tag information collision message,

may be the estimated number of third message receptions of the tag information non-detection message.

Thereafter, the helper device 100 may set a plurality of messages based on the first message reception number, the second message reception number, the third message reception number, the first message estimated reception number, the second message estimated reception number, and the third message estimated reception number. It is possible to estimate the estimated number of tags of any one of the estimated frames of .

In this case, the helper device 100 may calculate the estimated number of first message reception, the estimated second message reception number, and the estimated third message reception number using Equation 5 below.

는 프레임 인덱스가 i_tep인 추정 프레임의 추정 태그 수이고,

은 슬롯의 예상 수의 집합이고,

은 슬롯의 산출 수의 집합일 수 있다.here,

is the estimated number of tags of the estimated frame whose frame index is i_tep,

is the set of expected number of slots,

may be a set of the calculated number of slots.

The helper apparatus 100 calculates the estimated number of tags for any one of the plurality of estimated frames, and then calculates an average between the estimated number of tags calculated so far.

Thereafter, the helper device 100 increases the number of estimated frames (n _frame ) in which the estimated number of tags is estimated and the frame index i_tep by 1, respectively.

The helper apparatus 100 repeats the above-described average calculation until the number of estimated frames with the estimated number of estimated tags (n _frame ) is less than the threshold estimated number of frames (n _{frame_threshold} ), and the number of estimated frames with the estimated number of estimated tags (n) _frame ) exceeds the threshold estimated frame number (n _{frame_threshold} ), the average between the calculated estimated number of tags is determined as the number of tags.

Hereinafter, a process in which the backscatter communication system for estimating the number of tags using the operation period and the message according to an embodiment of the present invention adjusts the slot counter parameter during the communication period will be described.

Table 1 is a table for explaining an adjustment algorithm used by the system for calculating frame throughput using slot counter parameters according to an embodiment of the present invention, and Table 2 is a table for describing frame throughput calculation using slot counter parameters according to an embodiment of the present invention. This is a table to explain the commands and messages that the system transmits and receives during the communication section.

<Table 1>

<Table 2>

Referring further to Tables 1 and 2, the helper device 100 receives a communication request message including the number of tags from the reader device 200 during the request period, or includes the number of tags from the reader device 200 during the request period. If the number of tags is estimated during the tag count estimation period by receiving the communication request message that is not communicated, the communication period may be started.

First, the helper device 100 determines the maximum throughput ( _{Th max , i_cp} ) can be initialized. Here, initialization may mean setting each variable to “0”.

The helper device 100 calculates the throughput of the communication frame based on the remaining number of tags (n _{i_cp} ) indicating the number of tag devices waiting for reflection or absorption of the packet during the communication frame with the frame index i_cp, or the number of additional communication frames ( n _{ext_frame} ) and adjust the slot counter parameter based on the calculated throughput or the set number of additional communication frames.

Specifically, the helper device 100 does not receive the tag information detection message from the reader device 200 during any one of the plurality of communication frames, and thus the number of tag devices 300 waiting for reflection or absorption of the packet. When the indicated number of remaining tags exceeds a preset reference number of remaining tags, a throughput of the communication frame may be calculated, and a slot counter parameter may be adjusted based on the calculated throughput.

Here, the preset reference number of remaining tags may be “1”.

More specifically, when the number of remaining tags exceeds a preset reference number of remaining tags, the helper device 100 may initialize the number of additional communication frames. Here, initialization may mean setting the number of additional communication frames to “-1”.

The number of additional communication frames may be a number used when the number of tags received and included in the communication request message or the number of tags estimated during the tag number estimation period is less than the actual number (n _{act_tag} ) of the plurality of tag devices 300 .

Thereafter, the helper device 100 may set the second arbitrary slot counter parameter to any one of the slot counter parameter range “0 to the maximum slot counter parameter (Q _max )”. In this case, the helper device 100 may initially set the second arbitrary slot counter parameter to 0, add 1 to it, and set it up to the maximum slot counter parameter.

Here, the second arbitrary slot counter parameter may be an integer greater than or equal to 0.

Also, the maximum slot counter parameter may be a maximum value that can be set as the second arbitrary slot counter parameter.

The helper device 100 may calculate the throughput of the communication frame based on the second arbitrary slot counter parameter and determine the maximum throughput of the communication frame having the frame index i_cp based on the second arbitrary slot counter parameter.

Specifically, if the second arbitrary slot counter parameter is a preset reference slot parameter, the helper device 100 may determine the throughput of the communication frame to which the second arbitrary slot counter parameter is input as the maximum throughput of the communication frame.

In this case, the preset reference slot parameter may be “0”.

To this end, the helper device 100 may calculate the throughput of a specific frame by using the throughput output function. For example, the helper device 100 may calculate the throughput of the communication frame having the frame index i_cp by inputting the second arbitrary slot counter parameter as an input, as a throughput output function, and the throughput is Th _{i_cp} (Q _temp ) can indicate

Next, if the second arbitrary slot counter parameter is a preset reference slot parameter, the helper device 100 may update and set the second arbitrary slot counter parameter to a slot counter parameter of a communication frame having a frame index of i_cp.

On the other hand, when the second arbitrary slot counter parameter exceeds the preset reference slot parameter, the helper device 100 sets the maximum value among the throughput of the communication frame to which the second arbitrary slot counter parameter is input and the maximum throughput of the previous communication frame. can be determined as the maximum throughput of the communication frame.

Thereafter, when the maximum throughput of the latest determined communication frame exceeds the throughput of the communication frame to which the second arbitrary slot counter parameter is input, the helper device 100 may maintain and set the previous slot counter parameter.

Conversely, if the maximum throughput of the latest determined communication frame is less than or equal to the throughput of the communication frame to which the second arbitrary slot counter parameter is input, the helper device 100 sets the second arbitrary slot counter parameter to the communication frame in which the frame index is i_cp. It can be set by updating the slot counter parameter of

The helper device 100 may adjust the slot counter parameter while sequentially changing and setting the second slot counter parameter to any one of the slot counter parameter ranges.

Meanwhile, if the number of remaining tags is less than or equal to a preset reference number of remaining tags, the helper device 100 may set the number of additional additional communication frames by increasing the number. Specifically, when the number of remaining tags is less than or equal to the preset reference number of remaining tags, the helper device 100 may set the number of additional communication frames by increasing the number of previous additional communication frames by “1”.

Subsequently, the helper device 100 may set the number of additional communication frames as a slot counter parameter of a communication frame having a frame index of i_cp.

On the other hand, the helper device 100 broadcasts a query command in the first slot of the first communication frame of the communication section, transmits a query repeat command in the second slot, and broadcasts a query adjustment command in the first slot of the second communication frame of the communication section After casting, the query repeat command can be transmitted in the second slot.

Hereinafter, a process in which the backscatter communication system for estimating the number of tags using the operation section and the message according to an embodiment of the present invention calculates the number of remaining tags and calculates the throughput of the communication frame will be described.

When the frame index indicates the first (0), the helper device 100 may calculate the remaining number of tags as the number of tags received from the reader device 200 or the number of tags estimated and determined during the tag number estimation period.

Conversely, when the frame index indicates the second (1) or more, the helper device 100 calculates the number of tags received from the reader device 200 or the number of tags received during the previous communication frame from the number of tags estimated and determined during the tag count estimation period. It can be calculated by subtracting the fourth message reception number of the tag information detection message.

In this case, the helper device 100 may calculate the remaining number of tags using Equation 6 below.

는 잔여 태그 수이고,

는 이전 통신 프레임 동안 수신된 태그 정보 감지 메시지의 제4 메시지 수신 수 일 수 있다.here,

is the number of remaining tags,

may be the fourth message reception number of the tag information detection message received during the previous communication frame.

Table 3 is a table showing the structure of a slot in which a tag information detection message is transmitted and received in the slot counter parameter adjustment system for improving network performance according to an embodiment of the present invention.

<Table 3>

Referring further to Table 3, the helper device 100 may calculate the throughput of the communication frame based on the payload size of tag information detected during the communication frame and the frame time length of the communication frame.

In detail, the helper device 100 configures the frame based on a first ratio of the payload size per tag information, the preamble size per tag information, and the number of slots in which the tag information detection message is expected to be transmitted and received among a plurality of slots of the communication frame. It is possible to calculate the payload size of tag information detected during the operation.

Here, the preamble size per tag information may be 8 bits.

In this case, the helper device 100 uses the following Equations 7 to 12 to determine a first ratio of the number of slots in which the tag information detection message is expected to be transmitted and received among the plurality of slots of the communication frame, among the plurality of slots of the communication frame. A second ratio of the number of slots in which the tag information collision message is expected to be transmitted/received and a third ratio of the number of slots in which the tag information non-detection message is expected to be transmitted/received among the plurality of slots of the communication frame may be calculated.

는 통신 프레임의 복수의 슬롯 중 태그 정보 감지 메시지가 송수신될 것으로 예상되는 슬롯의 수의 제1 비율이고,

는 프레임 인덱스가 i_cp인 통신 프레임의 복수의 슬롯 중 태그 정보 감지 메시지가 송수신될 것으로 예상되는 슬롯의 수의 제1 비율이고,

는 통신 프레임의 복수의 슬롯 중 태그 정보 충돌 메시지가 송수신될 것으로 예상되는 슬롯의 수의 제2 비율이고,

는 프레임 인덱스가 i_cp인 통신 프레임의 복수의 슬롯 중 태그 정보 충돌 메시지가 송수신될 것으로 예상되는 슬롯의 수의 제2 비율이고,

는 통신 프레임의 복수의 슬롯 중 태그 정보 미감지 메시지가 송수신될 것으로 예상되는 슬롯의 수의 제3 비율이고,

는 프레임 인덱스가 i_cp인 통신 프레임의 복수의 슬롯 중 태그 정보 미감지 메시지가 송수신될 것으로 예상되는 슬롯의 수의 제3 비율일 수 있다.here,

is a first ratio of the number of slots in which a tag information detection message is expected to be transmitted and received among a plurality of slots of a communication frame,

is a first ratio of the number of slots in which a tag information detection message is expected to be transmitted and received among a plurality of slots of a communication frame having a frame index of i_cp,

is a second ratio of the number of slots in which a tag information collision message is expected to be transmitted and received among a plurality of slots of a communication frame,

is a second ratio of the number of slots in which a tag information collision message is expected to be transmitted and received among a plurality of slots of a communication frame having a frame index of i_cp,

is a third ratio of the number of slots in which a tag information non-detection message is expected to be transmitted and received among a plurality of slots of a communication frame,

may be a third ratio of the number of slots in which a tag information non-detection message is expected to be transmitted and received among a plurality of slots of a communication frame having a frame index of i_cp.

On the other hand, the helper device 100 is a first slot time length sum indicating the sum of the slot time lengths of the slots in which the tag information detection message is expected to be transmitted and received among the plurality of slots of the communication frame, and the tag information collision among the plurality of slots of the communication frame. A second slot time length sum representing the sum of the slot time lengths of slots in which messages are expected to be transmitted and received, and a third slot time length sum representing the slot time length sum of the slots in which the tag information non-detection message is expected to be transmitted and received among a plurality of slots of the communication frame The frame time length of the communication frame may be calculated based on the sum of the slot time lengths.

To this end, the helper device 100 determines the first slot time length of each slot in which the tag information detection message is expected to be transmitted and received among the plurality of slots of the communication frame, the query command time length, the query repetition command time length, and the query adjustment command time It can be calculated based on the length, the tag information backscattering time length, the SIFS time length, and the tag information detection message time length.

The helper device 100 sets the second slot time length of each slot in which the tag information collision message is expected to be transmitted and received among the plurality of slots of the communication frame, the query command time length, the query repetition command time length, the query adjustment command time length, and the tag It can be calculated based on the information backscattering time length, the SIFS time length, and the tag information collision message time length.

The helper device 100 determines the third slot time length of each slot in which the tag information non-detection message is expected to be transmitted/received among the plurality of slots of the communication frame, the query command time length, the query repeat command time length, the query adjustment command time length, It can be calculated based on the tag information backscattering time length, the SIFS time length, and the tag information undetected message time length.

Thereafter, the helper device 100 calculates the sum of the first slot time lengths based on the first slot time length and the first ratio, and calculates the sum of the second slot time lengths based on the second slot time length and the second ratio. and a sum of the third slot time lengths may be calculated based on the third slot time length and the third ratio.

Specifically, the helper device 100 may calculate the frame time length of the communication frame by summing the sum of the first slot time length, the second slot time length sum, and the third slot time length sum.

In this case, the helper device 100 may calculate the tag information backscattering time length, the first slot time length, the second slot time length, and the third slot time length by using Equations 13 to 16 below.

는 태그 정보 백스캐터링 시간길이고,

는 CTS-to-Self 패킷 시간길이고,

는 패킷 시간길이고,

는 단기 인터 프레임 스페이스(Short Inter Frame Space) 시간길이고,

는 제1 슬롯 시간길이고,

는 제2 슬롯 시간길이고,

는 제3 슬롯 시간길이고,

는 쿼리 명령 시간길이고,

는 쿼리반복 명령 시간길이고,

는 쿼리조정 명령 시간길이고,

는 태그 정보 감지 메시지 시간길이고,

는 태그 정보 충돌 메시지 시간길이고,

는 태그 정보 미감지 메시지 시간길이일 수 있다.here,

is the tag information backscattering time length,

is the CTS-to-Self packet time length,

is the packet time length,

is the Short Inter Frame Space time length,

is the first slot time length,

is the second slot time length,

is the third slot time length,

is the query command time length,

is the length of the query repeat command,

is the length of the query reconciliation command,

is the tag information detection message time length,

is the tag information collision message time length,

may be the tag information non-detection message time length.

The helper device 100 may calculate the ratio of the frame time length of the communication frame to the payload size of tag information sensed during the communication frame as the throughput of the communication frame.

In this case, the helper device 100 may calculate the throughput of the communication frame by using Equation 17 below.

는 프레임 인덱스가 i_cp인 통신 프레임의 처리량일 수 있다.here,

may be the throughput of a communication frame in which the frame index is i_cp.

In the backscatter communication method for estimating the number of tags using the operation period and the message according to an embodiment of the present invention, in step S1 , the reader device may transmit a communication request message in the request period.

In step S2, the helper device, based on the communication request message, repeats a query command and query including a first arbitrary slot counter parameter at each start end of a plurality of slots included in a plurality of estimation frames included in the tag number estimation section It can broadcast any of the commands and packets.

In step S3, the plurality of tag devices sets a slot counter based on a first arbitrary slot counter parameter in the first slot among the plurality of slots, and reflects or absorbs the packet based on whether the slot counter is a preset reference slot counter. This enables the reader device to detect the tag information.

In step S4, the tag information detection message, the tag information collision message and the tag information not detected at each end of the plurality of slots based on the detection result of the reader device detecting the tag information from the plurality of tag devices during each of the plurality of slots Any one of the messages can be sent to the helper device.

In step S5 , the helper device may determine the number of tags of the plurality of tag devices based on the tag information detection message, the tag information collision message, and the tag information non-detection message.

On the other hand, the computer program according to an embodiment of the present invention may be stored in a computer-readable recording medium so as to be combined with a computer that is hardware to perform the method according to an embodiment of the present invention.

The steps of a method or algorithm described in connection with an embodiment of the present invention may be implemented directly in hardware, as a software module executed by hardware, or by a combination thereof. A software module may include random access memory (RAM), read only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, hard disk, removable disk, CD-ROM, or It may reside in any type of computer-readable recording medium well known in the art to which the present invention pertains.

So far, the present invention has been focused on a preferred embodiment. Those of ordinary skill in the art to which the present invention pertains will understand that the present invention can be implemented in modified forms without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive point of view. The scope of the present invention is indicated in the claims rather than the foregoing description, and all differences within an equivalent scope should be construed as being included in the present invention.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the following by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

100: helper device
200: reader device
300: a plurality of tag devices

Claims (10)

a reader device for transmitting a communication request message in the request section;
Any one of a query command and a query repeat command including a first arbitrary slot counter parameter at each start end of a plurality of slots included in a plurality of estimated frames included in the number of tags estimation section based on the communication request message and a packet a helper device that broadcasts; and
In the first slot among the plurality of slots, a slot counter is set based on the first arbitrary slot counter parameter, and the reader device is configured to reflect or absorb the packet based on whether the slot counter is a preset reference slot counter. a plurality of tag devices that detect tag information; and
The reader device
Any one of a tag information detection message, a tag information collision message, and a tag information non-detection message at each end of the plurality of slots based on a detection result of detecting the tag information from the plurality of tag devices during each of the plurality of slots to the helper device,
The helper device
and determining the number of tags of the plurality of tag devices based on the tag information detection message, the tag information collision message, and the tag information non-detection message.
A backscatter communication system that estimates the number of tags using the operating interval and message.
According to claim 1,
The plurality of tag devices
Upon receiving the query command, a slot counter range is set by using the first arbitrary slot counter parameter, any one of the reserved slot counters included in the slot counter range is set as the slot counter, and the query Characterized in that when receiving a repeat command, the slot counter is decremented and set
A backscatter communication system that estimates the number of tags using the operating interval and message.
3. The method of claim 2,
The plurality of tag devices
If the slot counter is the preset reference slot counter, the reader device detects the tag information by reflecting or absorbing the packet.
A backscatter communication system that estimates the number of tags using the operating interval and message.
According to claim 1,
The reader device
When the tag information is detected from any one of the plurality of tag devices, the tag information detection message is transmitted to the helper device, and when the tag information is detected from more than one of the plurality of tag devices, the tag information is detected transmitting the tag information collision message to the helper device, and transmitting the tag information non-detection message to the helper device when the tag information is not detected
A backscatter communication system that estimates the number of tags using the operating interval and message.
5. The method of claim 4,
The helper device
The number of first message receptions of the tag information detection message received during any one of the plurality of estimated frames, the number of second message receptions of the tag information collision message, and the number of third message receptions of the tag information non-detection message characterized by calculating
A backscatter communication system that estimates the number of tags using the operating interval and message.
6. The method of claim 5,
The helper device
The estimated number of first message receptions of the tag information detection message estimated to be received during any one of the estimated frames among the plurality of estimated frames, the estimated number of second messages received of the tag information collision message, and the tag information non-detection message Calculating the estimated number of third messages received
A backscatter communication system that estimates the number of tags using the operating interval and message.
7. The method of claim 6,
The helper device
the plurality of the plurality of messages based on the number of first message receptions, the second message reception number, the third message reception number, the first message estimated reception number, the second message estimated reception number, and the third message estimated reception number estimating the estimated number of tags of any one of the estimated frames of
A backscatter communication system that estimates the number of tags using the operating interval and message.
8. The method of claim 7,
The helper device
and determining an average between the estimated number of tags in each of the plurality of estimated frames as the number of tags of the plurality of tag devices.
A backscatter communication system that estimates the number of tags using the operating interval and message.
Transmitting, by the reader device, a communication request message in the request period;
Any one of a query command and a query repeat command, wherein the helper device includes a first arbitrary slot counter parameter at each start end of a plurality of slots included in a plurality of estimation frames included in the tag number estimation section based on the communication request message broadcasting a packet with one;
a plurality of tag devices set a slot counter based on the first arbitrary slot counter parameter in a first slot among the plurality of slots, and reflect or absorb the packet based on whether the slot counter is a preset reference slot counter transmitting the tag information to the reader device;
A tag information detection message, a tag information collision message, and no tag information detection at each end of the plurality of slots based on a detection result of the reader device detecting the tag information from the plurality of tag devices during each of the plurality of slots sending any one of the messages to the helper device; and
determining, by the helper device, the number of tags of the plurality of tag devices based on the tag information detection message, the tag information collision message, and the tag information non-detection message;
A backscatter communication method for estimating the number of tags using the operating period and message.
A computer program stored in a computer-readable recording medium in combination with a computer, which is hardware, to perform the method of claim 9.

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