KR20230035826A - apparatus for determining size of frame in multiple access network environment and method thereof - Google Patents

Abstract

According to an embodiment of the present invention, a device for determining a frame size in a multi-access network environment comprises: an information collection unit that collects information corresponding to a current frame from a plurality of terminals accessing a multi-access network environment; a frame size determination unit for determining a frame size of a next frame based on the number of terminals performing energy harvesting among the plurality of terminals by using the collected information; and an information transmitting unit for transmitting information on the determined frame size to the plurality of terminals.

Description

Apparatus for determining size of frame in multiple access network environment and method thereof

The present invention relates to an apparatus and method for determining a frame size in a multi-access network environment.

With the development of information and communication technology, a plurality of terminals can simultaneously access a wireless network and exchange data. At this time, a base station or wireless access point (AP) performs scheduling so that each terminal can smoothly transmit and receive data. Do it.

Terminals performing operations based on the Framed Slotted ALOHA (FSA) protocol transmit data by selecting a random time slot within a frame determined by a data collection device. At this time, when there is only one terminal that selects one time slot, data can be successfully transmitted and no problem occurs. However, when two or more terminals select one slot, mutual collision may occur, which may be a problem. In addition, in the process of data transmission based on the FSA protocol, if no terminal selects any slot, the corresponding slot becomes an idle slot and communication resources may be wasted.

In this case, when the number of terminals is larger than the frame size, a lot of collisions occur, and when the number of terminals is smaller than the frame size, the number of idle slots increases and the network throughput decreases. Therefore, in order to minimize the number of collision slots and the number of idle slots, the frame size should be set according to the number of UEs participating in contention. However, since the FSA protocol uses a fixed frame size, the throughput is low in a network in which the number of UEs participating in contention changes dynamically according to the energy reserve of the UE and network entry/exit.

In addition, in an existing wireless power transmission network (WPCN, Wireless Powered Communication Network), a terminal may harvest energy through a wireless RF signal from an AP at a predetermined time. A terminal harvesting enough energy to transmit data may transmit data using the harvested energy. At this time, if the frame size is set large, the energy harvesting time of the terminals increases, so sufficient energy can be supplied to a plurality of terminals, but the data throughput performance may be lowered. Since the size of the frame affects both the amount of energy harvested by the UE and the data throughput, a method for determining an appropriate frame size according to the change in the number of UEs is required in order for the AP to maximize the data throughput and energy harvest of the UE.

The problem to be solved by the present invention is to solve the above problem, the frame size of the next frame based on the number of terminals performing energy harvesting among a plurality of terminals connected to a multi-access network environment in the current frame. It is intended to provide an apparatus and method for determining.

An object of the present invention is to provide an apparatus and method for determining the frame size in consideration of outflow of some of the plurality of terminals connected to the multi-access network environment or inflow of new terminals.

However, the problem to be solved by the present invention is not limited to those mentioned above, and another problem to be solved that is not mentioned can be clearly understood by those skilled in the art from the description below. will be.

An apparatus for determining a frame size in a multi-access network environment according to an embodiment of the present invention includes an information collection unit that collects information corresponding to a current frame from a plurality of terminals connected to the multi-access network environment; a frame size determining unit for determining a frame size of a next frame based on the number of terminals performing energy harvesting among the plurality of terminals using the collected information; and an information transmitter configured to transmit information on the determined frame size to the plurality of terminals.

The energy harvesting may receive energy from an Access Point (AP).

The frame size determining unit may calculate an amount of energy harvested during the energy harvesting and an amount of energy consumed when the terminal transmits data.

The frame size determiner may predict an operation to be performed by the terminal in the next frame by comparing the difference between the calculated energy amount and a predetermined threshold value, and determine the frame size based on the prediction result.

The frame size determination unit may determine the frame size of the next frame based on the size of the current frame.

The frame size determiner may determine the frame size using a reinforcement learning algorithm.

The frame size determiner may set states corresponding to different frame sizes and determine the frame size by considering compensation according to switching between states.

The frame size determination unit may determine the frame size based on the number of successful collision slots, the number of successful data transmission slots, and the number of idle slots among the slots included in the current frame.

The number of the plurality of connected terminals may change at least in part for each frame.

A method for determining a frame size in a multi-access network environment according to an embodiment of the present invention includes collecting information corresponding to a current frame from a plurality of terminals connected to the multi-access network environment; determining a frame size of a next frame based on the number of terminals performing energy harvesting among the plurality of terminals using the collected information; and transmitting information on the determined frame size to the plurality of terminals.

The energy harvesting may receive energy from an Access Point (AP).

The method may include calculating an amount of energy harvested during the energy harvesting; and calculating an amount of energy consumed by the terminal to transmit data.

The method may further include an operation of predicting an operation to be performed by the terminal in the next frame by comparing the difference between the calculated amount of energy with a preset threshold, and the frame size may be determined based on the prediction result.

The frame size of the next frame may be determined based on the size of the current frame.

The frame size may be determined using a reinforcement learning algorithm.

The method may further include setting a state corresponding to each of the different frame sizes, and the frame size may be determined in consideration of compensation for switching between states.

The frame size may be determined based on the number of successful collision slots, the number of successful data transmission slots, and the number of idle slots among the slots included in the current frame.

The number of the plurality of connected terminals may change at least in part for each frame.

A computer program stored in a computer readable recording medium according to an embodiment of the present invention includes an operation of collecting information corresponding to a current frame from a plurality of terminals connected to a multi-access network environment; determining a frame size of a next frame based on the number of terminals performing energy harvesting among the plurality of terminals using the collected information; and transmitting the information on the determined frame size to the plurality of terminals.

A computer readable recording medium storing a computer program according to an embodiment of the present invention includes an operation of collecting information corresponding to a current frame from a plurality of terminals connected to a multi-access network environment; determining a frame size of a next frame based on the number of terminals performing energy harvesting among the plurality of terminals using the collected information; and transmitting the information on the determined frame size to the plurality of terminals.

According to an embodiment of the present invention, an apparatus and method for determining a frame size in a multi-access network environment may differently determine a frame size using information on a plurality of terminals connected to the multi-access network environment. Through this, data transmission efficiency can be increased.

According to an embodiment of the present invention, the apparatus and method for determining the frame size in the multi-access network environment considers that the number of the plurality of terminals connected to the multi-access network environment may change at least partially for each frame. Since the size can be determined, it can be applied more appropriately to the actual environment than the prior art.

1 is a diagram illustrating a multi-access network environment in which an apparatus for determining a frame size and a plurality of terminals perform operations according to an embodiment of the present invention.
2 is a diagram illustrating operations of a plurality of terminals in a multi-access network environment according to an embodiment of the present invention.
3 is a block diagram of an apparatus for determining a frame size according to an embodiment of the present invention.
4 is a diagram illustrating a plurality of MDP-based states and an action of converting each state to each other according to an embodiment of the present invention.
5 is a flowchart illustrating a method of determining a frame size performed by an apparatus for determining a frame size according to an embodiment of the present invention.
6 is a flowchart illustrating an operation in which a Q-learning algorithm is performed according to an embodiment of the present invention.
7 is a flowchart illustrating an operation of a terminal according to an embodiment of the present invention.
8 is a graph comparing a success rate according to an existing FSA scheme and a success rate according to a method performed by the frame size determining apparatus according to an embodiment of the present invention.
9 is a graph comparing performance according to an existing FSA method and a method performed by the frame size determining apparatus according to an embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

In describing the embodiments of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the embodiments of the present invention, which may vary according to the intention or custom of a user or operator. Therefore, the definition should be made based on the contents throughout this specification.

1 is a diagram illustrating a multi-access network environment 10 in which a frame size determining apparatus 100 and a plurality of terminals 200 perform operations according to an embodiment of the present invention.

Referring to FIG. 1, the multi-network environment 10 includes a plurality of the frame size determining device 100, the energy transmission device 150, and a data transmission terminal 200a and an energy harvesting terminal 200b. The terminal 200 may be included.

The multi-network environment 10 may use one of various wireless networks. The various wireless networks include CDMA, GSM, W-CDMA, TD-SCDMA, WiBro, LTE, EPC, wireless LAN, Wi-Fi, Bluetooth, Zigbee, and WFD (Wi-Fi). -Fi Direct), Ultra Wideband (UWB), Infrared Data Association (IrDA), Bluetooth Low Energy (BLE), and Near Field Communication (NFC).

According to various embodiments of the present disclosure, the multi-network environment 10 may use a low-power network to increase efficiency by reducing power consumption.

Also, according to various embodiments of the present invention, the multi-network environment 10 may operate based on a Medium Access Control (MAC) protocol.

The number of terminals 200 connected to the multi-access network environment 10 may be at least partially different for each frame. For example, some of the terminals maintaining access in the current frame may leave the multi-access network environment 10 out of coverage of the AP due to location movement or the like. In addition, other terminals not accessed in the current frame may enter the multi-access network environment 10 while moving to the coverage of the AP.

The frame size determining device 100 may collect information from a plurality of terminals 200 connected to the multi-network environment 10 . The collected information may be information on the current frame.

The frame size determining apparatus 100 may determine the frame size of the next frame using the collected information. For example, the frame size determining apparatus 100 may determine the frame size based on the number of energy harvesting terminals 200b performing energy harvesting among the collected information.

The frame size determining device 100 may calculate the amount of energy harvested by the energy harvesting terminal 200b. In addition, the frame size determining device 100 may calculate the amount of energy consumed by the data transmission terminal 200a to transmit data. In this case, the frame size determining apparatus 100 may compare the calculated energy difference with a threshold value to predict an operation to be performed by the plurality of terminals 200 in the next frame. For example, the frame size determination apparatus 100 may predict whether each of the plurality of terminals 200 will transmit data or perform energy harvesting in the next frame, and determine the frame size based on the prediction result. can decide

The frame size determining apparatus 100 may determine the frame size of the next frame based on the frame size of the current frame. For example, the frame size determining apparatus 100 may determine the frame size of the next frame by maintaining, reducing, or increasing the frame size of the current frame.

The frame size determining apparatus 100 may determine the frame size using a reinforcement learning algorithm. In this case, the frame size determining apparatus 100 may set a plurality of states corresponding to different frame sizes, and determine the frame size by considering compensation according to switching between states. For example, the frame size determining apparatus 100 may determine the frame size by performing a Q-learning algorithm based on a Markov-Decision Process (MDP).

The frame size determining apparatus 100 may determine the frame size based on the number of successful collision slots, the number of successful data transmission slots, and the number of idle slots among a plurality of slots included in the current frame.

For example, the frame size determining apparatus 100 may determine the next frame size to correspond to the number of terminals participating in contention in order to minimize the number of collision slots and the number of idle slots. In this case, the size of the next frame may be the same as the number of terminals participating in the competition, but is not limited thereto.

The frame size determining device 100 may transmit information on the determined frame size to the plurality of terminals 200 . According to various embodiments of the present disclosure, the terminal 200 may be a mobile phone or a smart phone, but is not limited thereto. For example, the terminal 200 may be a vehicle capable of communication or a device capable of various communications using IoT.

Referring to FIG. 1, although a data transmission terminal 200a and an energy harvesting terminal 200b are shown separately, this is only functionally dividing the operation of a plurality of terminals 200, and a data transmission terminal in another frame. 200a may be the energy harvesting terminal 200b, and conversely, the energy harvesting terminal 200b may be the data transmission terminal 200a.

The data transmission terminal 200a may select a slot and transmit data using the information on the size of the received frame.

The energy harvesting terminal 200b may receive energy from an AP. According to various embodiments of the present disclosure, the frame size determining device 100 may be an AP, and the energy transmission device 150 may also be the AP. That is, the AP may operate as a Hybrid-AP (H-AP).

Since the plurality of terminals 200 consume energy during data transmission, energy must be continuously harvested to maintain network connection. Terminals capable of energy harvesting can harvest energy by utilizing external ambient energy such as solar heat, geothermal heat, wind power, etc., and can also harvest energy through a wireless Radio Frequency (RF) energy signal of the energy transmission device 150. . In this case, the energy transmission device 150 may be a Power Beacon (PB).

2 is a diagram illustrating operations of a plurality of terminals under a multi-access network environment 10 according to an embodiment of the present invention.

Referring to FIG. 2 , operations of a first terminal 201 to a fifth terminal 205 in a first frame and a second frame are illustrated. Each frame is shown as including 7 slots, but is not limited thereto. According to various embodiments of the present disclosure, the frame size determining apparatus 100 may differently determine the size of the second frame based on the size of the first frame.

Referring to the first frame, the first terminal 201, the second terminal 202, the fourth terminal 204, and the fifth terminal 205 are performing data transmission, and the third terminal 203 ) is performing energy harvesting. As shown in FIG. 2 , the first terminal 201 selects the 4th slot and the second terminal 202 selects the 1st slot, indicating successful data transmission. However, both the 4th terminal 204 and the 5th terminal 205 select the 6th slot, so it can be known that a collision has occurred.

Referring to the second frame, the first terminal 201, the third terminal 203, the fourth terminal 204, and the fifth terminal 205 are performing data transmission, and the second terminal ( 202) is performing energy harvesting. The third terminal 203, which has performed energy harvesting in the first frame, performs data transmission, and the second terminal 202, which has performed data transmission in the first frame, has insufficient energy and performs energy harvesting. It can be confirmed that the

According to various embodiments of the present disclosure, the frame size determining apparatus 100 determines an operation of the first terminal 201 to the fifth terminal 205 in the first frame, for example, data transmission or energy harvesting. The frame size of the second frame may be determined to be 7 slots based on the ting operation.

Furthermore, the frame size determining apparatus 100 may determine the frame size of the third frame (not shown) based on the operations of the first terminal 201 to the fifth terminal 205 in the second frame. .

3 is a block diagram of an apparatus 100 for determining a frame size according to an embodiment of the present invention.

Referring to FIG. 3 , the frame size determining device 100 may include an information collection unit 110 , a frame size determination unit 120 , an information transmission unit 130 , and a memory 140 . However, each component of the frame size determining device 100 is classified functionally and may not be actually physically separated. Also, components of the frame size determining device 100 or at least some of the components may be implemented as a System on Chip (SoC).

The government collection unit 110 may collect information corresponding to a current frame from a plurality of terminals 200 connected to the multi-network environment 10 . The information may include information about what operation the terminal 200 performs in the current frame, eg, data transmission or energy harvesting.

According to an embodiment of the present invention, the energy harvesting may be receiving energy from a PB. Also, according to an embodiment of the present invention, an AP may perform the role of the PB.

The frame size determination unit 120 may determine the frame size of the next frame based on the number of terminals performing energy harvesting among the plurality of terminals 200 using the collected information.

The frame size determiner 120 may calculate the amount of energy harvested during the energy harvesting and the amount of energy consumed when the terminal 200 transmits data. Specifically, the amount of energy harvested during the energy harvesting may be calculated using Equations 1 and 2 below, and the amount of energy consumed when the terminal 200 transmits data is calculated using Equation 3 below. can

[Formula 1]

[Equation 2]

[Formula 3]

는 현재 프레임에서 하베스팅하는 에너지량을 의미한다. 여기서, L은 현재 프레임의 프레임 크기를 나타내고,

은 상기 단말(200)이

의 슬롯 시간 동안 수신한 전력 세기를 나타낸다.

는 에너지 변환 효율로서 0 이상 1 이하의 범위에서 임의의 값을 가질 수 있다.In Equation 1 and Equation 2 above,

denotes the amount of energy harvested in the current frame. Here, L represents the frame size of the current frame,

is the terminal 200

Indicates the power intensity received during the slot time of

Is energy conversion efficiency and may have an arbitrary value in the range of 0 or more and 1 or less.

는 상기 단말(200)이 데이터를 전송하는 전력 세기를 나타낼 수 있다. 본 발명의 일 실시 예에 따르면, 상기 전력 세기는 상기 단말(200) 별로 상이할 수 있다. In Equation 3 above

may represent the power intensity through which the terminal 200 transmits data. According to an embodiment of the present invention, the power intensity may be different for each terminal 200 .

The frame size determiner 120 may predict an operation to be performed by the terminal 200 in the next frame by comparing the difference between the calculated energy amount and a predetermined threshold value. For example, a terminal in which the difference between the amount of energy harvesting and the amount of energy consumed for transmitting the data is less than the threshold value becomes an energy harvesting terminal 200b, and a terminal in which the difference is greater than the threshold value transmits data. It may be the terminal 200a.

The frame size determining unit 120 may determine the frame size of the next frame based on the size of the current frame. For example, the frame size determining unit 120 may determine whether to maintain, decrease, or increase the frame size of the current frame.

The frame size determiner 120 may determine the frame size using a reinforcement learning (Q-learning) algorithm. For example, the frame size determiner 120 may perform a Q-learning algorithm for finding an optimal action based on MDP. The MDP will be described with reference to FIG. 4 .

4 is a diagram illustrating a plurality of MDP-based states and an action of converting each state to each other according to an embodiment of the present invention.

Referring to FIG. 4 , s ₁ to s _m represent states corresponding to different frame sizes. In addition, a represents an action representing a transition between each state. For example, a _1,2 may represent an action of transitioning a state from s ₁ to s ₂ .

The frame size determiner 120 may update the Q value for each action (a) in all states (s ₁ to s _m ) and perform Q-learning.

Specifically, the frame size determiner 120 initializes the Q value (Q ₀ (s,a)) and the frame size (s ₀ ), and informs the terminal 200 of the initial frame size. This may be performed through the information transmission unit 130. In this case, the plurality of terminals 200 may transmit data using an arbitrary slot within a frame through contention.

함수를 이용하여 다음 상태 s_t+1를 결정할 수 있다. 이 때의 행동은 상기 현재 프레임에서의 행동에 의해 상태가 변하는 것이므로 a_t로 나타낼 수 있다.The frame size determiner 120 determines the next frame (t+1) by using the number of collision slots (C _t ), the number of successful slots (S _t ), and the number of idle slots (I _t ) in the t-th frame. The frame size of (s _t+1 (m)) can be calculated. The frame size determiner 120 calculates the value of Equation 4 from states s _t and v _t in the current frame t.

A function can be used to determine the next state s _t+1 . Since the action at this time is a change in state by the action in the current frame, it can be expressed as a _t .

[Formula 4]

는 수식 5 및 수식 6과 같이 이용될 수 있다.According to various embodiments of the present invention,

may be used as in Equations 5 and 6.

[Formula 5]

[Formula 6]

where β and χ can be arbitrary constants.

The frame size determiner 120 may update the Q value (Q _t+1 (s,a)) of the next frame (t+1) using Equation 7 below.

[Formula 7]

이고, r_t=S_t일 수 있다. 또한, α는 Q-learning에서 사용되는 학습률(learning rate) 값이고, γ는 할인율(discount rate) 값이다.here,

, and r _t =S _t . Also, α is a learning rate value used in Q-learning, and γ is a discount rate value.

Thereafter, the frame size determining unit 120 may start the t+1th frame and repeat the above operation.

According to various embodiments of the present invention, since the number of terminals 200 changes for each frame due to terminals entering the network and terminals leaving the network, the number of collision slots, the number of idle slots, and success The number of slots changes. Accordingly, the frame size determining unit 120 may determine an appropriate frame size through the Q-learning algorithm.

The information transmission unit 130 may transmit information on the determined frame size to the plurality of terminals 200, and based on this, the plurality of terminals 200 may perform an appropriate operation.

The memory 140 may store various data. For example, behavior information for each frame of the plurality of terminals 200 and the frame size determined by the frame size determination unit 120 may be stored in the memory 140 .

For example, the memory 140 may include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and floptical disks. It may be a computer readable recording medium, such as a hardware device specially configured to store and execute program instructions such as magneto-optical media and flash memory.

5 is a flowchart illustrating a frame size determination method performed by the frame size determination apparatus 100 according to an embodiment of the present invention.

Referring to FIG. 5 , the frame size determining device 100 may collect information corresponding to a current frame from a plurality of terminals 200 connected to the multi-access network environment 10 in operation S510.

In operation S520, the frame size determining device 100 may calculate an amount of energy harvested when the terminal 200 performs energy harvesting.

In operation S530, the frame size determining device 100 may calculate the amount of energy consumed by the terminal 200 to transmit data.

In operation S540, the frame size determination apparatus 100 compares the difference between the amount of energy calculated in operations S520 and S530 with a predetermined threshold value to predict an operation to be performed by the terminal 200 in the next frame.

In operation S550, the frame size determining apparatus 100 may determine the frame size of the next frame based on the predicted result in operation S540.

In operation S560, the frame size determination apparatus 100 may notify the plurality of terminals 200 of the frame size predicted in operation S550.

According to various embodiments of the present disclosure, operations S510 to S560 are illustrated as being performed in sequence, but are not limited thereto, and the order of at least some operations may be changed, or at least two or more operations may be performed simultaneously. . For example, operation S520 may be performed after operation S530 is performed, or operations S520 and S530 may be performed simultaneously.

6 is a flowchart illustrating an operation in which a Q-learning algorithm is performed according to an embodiment of the present invention.

Referring to FIG. 6 , in operation S605, the frame determining device 100 may initialize a Q table including status, operation, and compensation information.

In operation S610, the frame determining device 100 may determine an initial frame size and inform the plurality of terminals 200 of the determined initial frame size.

In operation S615, the frame determination apparatus 100 may set the number of idle slots, the number of collision slots, the number of successful slots, and time slot numbering to zero.

In operations S620 and S625, the frame determination device 100 adds 1 until the time slot numbering becomes the same value as the initial frame size determined in operation S610, and determines whether each corresponding time slot is an idle slot or whether data transmission is performed. It may be determined whether the slot was successful or a slot in which a collision occurred (operations S630 and S640). Specifically, when there is no terminal that has transmitted data in operation S630, the corresponding time slot becomes an idle slot. In addition, when there is a terminal that has transmitted data in operation S630, if there is no collision, the corresponding time slot becomes a slot in which data transmission is successful, and if there is a collision, the corresponding time slot becomes a collision slot.

In operation S635, when the time slot is an idle slot, the frame determination device 100 may add 1 to the number of idle slots, and in operation S645, the frame determination device 100 determines that the time slot is a success slot. , 1 may be added to the number of successful slots, and in operation S650, if the time slot is a collision slot, the frame determination apparatus 100 may add 1 to the number of collision slots.

If the time slot numbering exceeds the initial frame size determined in operation S610, operation S625 proceeds to operation S655, where the frame determining device 100 may calculate a reward from the number of successful slots.

In operation S660, the frame determining apparatus 100 may determine the frame size from the number of collision slots and the number of idle slots.

In operation S665, the frame determining device 100 may update the initial frame size to the frame size determined in operation S660 based on the reward information and operation.

7 is a flowchart illustrating the operation of the terminal 200 according to an embodiment of the present invention.

In operation S710, the terminal 200 may access the multi-access network environment 10.

In operation S720, the terminal 200 may receive information on the frame size from the frame determining device 100.

In operation S730, the terminal 200 may determine its own energy state.

In operation S740, the terminal 200 may compare the energy state determined in operation S730 with a preset threshold value, and if the energy state of the terminal 200 is greater than the threshold value, operation S740 may proceed to operation S750. .

In operation S750, the terminal 200 may select an arbitrary slot based on the information on the frame size received in operation S720.

In operation S760, the terminal 200 may transmit data using the slot selected in operation S750, and in operation S770, the terminal 200 may update the energy state of the terminal 200.

If the threshold is greater than the energy state of the terminal 200 in operation S740, operation S740 may proceed to operation S780.

In operation S780, the terminal 200 may perform energy harvesting in the corresponding frame, and in operation S790, the terminal 200 may update the energy state of the terminal 200.

8 and 9 are graphs comparing performance according to an existing FSA scheme and performance according to a method performed by the frame size determining apparatus 100 according to an embodiment of the present invention.

8 is a graph showing the success rate of data drilling, the higher the performance, the better the performance, and FIG. 9 is the graph showing the average delay, the lower the better the performance.

8 and 9, performance according to the method performed by the frame size determination apparatus 100 according to an embodiment of the present invention, performance according to the Wireless Powered Communication Network (WPCN) FSA scheme, and conventional Harvest- The performance according to the Then-Transmit (HT) FSA method is shown in each graph. In each example, the L value is the preset number of slots.

For reference, in the WPCN FSA scheme, terminals with high energy transmit data in a fixed frame size, and terminals with low energy collect energy without transmitting data. In addition, in the existing HT FSA method, terminals may receive energy and transmit data in a predetermined time slot before transmitting data.

Referring to FIGS. 8 and 9 , in the case of the FSA method in which the data size is determined, performance deteriorates when the number of terminals having a predetermined data size or more flows into the multi-access network environment 10 . On the other hand, in the case of the frame size determination method according to the embodiment of the present invention, it can be seen that good performance is maintained without being affected by an increase in the number of terminals.

In the case of FIG. 8 , in the embodiment of the present invention, the frame size is determined by learning the number of successes, collisions, and idle slots, so that even if the number of terminals 200 increases, the maximum success rate can be maintained while increasing the frame size. In addition, when the frame size is increased as the number of terminals 200 increases through learning, time for the terminal 200 to harvest sufficient energy is guaranteed to increase the number of terminals 200 participating in data transmission. can make it In an embodiment of the present invention, the optimal frame size can be determined adaptively not only when the number of terminals 200 is large, but also in a situation where the number of terminals 200 in the network continuously changes, so that optimal results suitable for various situations can be obtained. can be derived.

In the case of FIG. 9 , as the number of data transmission terminals 200a increases, the probability of occurrence of a collision increases, and the number of data retransmissions of the terminal 200 increases, resulting in an increase in data transmission delay time. However, in an embodiment of the present invention, latency performance may be improved by determining an optimal frame size through learning. When the size of the frame is larger than the number of terminals 200, the probability of collision between data transmissions is not large compared to the conventional method. However, when the size of the frame is smaller than the number of terminals 200, the terminal 200 causes collision It can be confirmed that the delay time increases rapidly in the conventional method because retransmission is continuously attempted.

Combinations of each block of the block diagram and each step of the flowchart accompanying the present invention may be performed by computer program instructions. Since these computer program instructions may be loaded into an encoding processor of a general-purpose computer, special-purpose computer, or other programmable data processing equipment, the instructions executed by the encoding processor of the computer or other programmable data processing equipment are each block or Each step in the flow chart creates means for performing the functions described. These computer program instructions may also be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular way, such that the computer usable or computer readable memory The instructions stored in may also produce an article of manufacture containing instruction means for performing the functions described in each block of the block diagram or each step of the flow chart. The computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to generate computer or other programmable data processing equipment. It is also possible that the instructions performing the processing equipment provide steps for executing the functions described in each block of the block diagram and each step of the flowchart.

Additionally, each block or each step may represent a module, segment or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative embodiments, it is possible for the functions recited in blocks or steps to occur out of order. For example, two blocks or steps shown in succession may in fact be performed substantially concurrently, or the blocks or steps may sometimes be performed in reverse order depending on their function.

The above description is merely an example of the technical idea of the present invention, and various modifications and variations can be made to those skilled in the art without departing from the essential qualities of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100: frame size determining device
110: information collection unit
120: frame size determining unit
130: information transmission unit
140: memory

Claims (20)

An apparatus for determining a frame size in a multi-access network environment,
an information collecting unit that collects information corresponding to a current frame from a plurality of terminals connected to the multi-access network environment;
a frame size determining unit for determining a frame size of a next frame based on the number of terminals performing energy harvesting among the plurality of terminals using the collected information; and
and an information transmitter configured to transmit information on the determined frame size to the plurality of terminals. According to claim 1,
The energy harvesting is to receive energy from an access point (AP), the frame size determination device. According to claim 1,
The frame size determining unit calculates the amount of energy harvested during the energy harvesting and calculates the amount of energy consumed when the terminal transmits data. According to claim 3,
The frame size determination unit predicts an operation to be performed by the terminal in the next frame by comparing the calculated difference between the amount of energy and a preset threshold,
To determine the frame size based on the prediction result, the frame size determining device. According to claim 1,
Wherein the frame size determination unit determines the frame size of the next frame based on the size of the current frame. According to claim 1,
Wherein the frame size determination unit determines the frame size using a reinforcement learning algorithm. According to claim 6,
The frame size determining unit sets states corresponding to different frame sizes, and determines the frame size in consideration of compensation according to switching between states. According to claim 1,
The frame size determining unit determines the frame size based on the number of successful collision slots, the number of successful data transmission slots, and the number of idle slots among the slots included in the current frame. According to claim 1,
The number of the plurality of connected terminals is at least partially changed for each frame, the frame size determining device. A method for determining a frame size in a multi-access network environment,
collecting information corresponding to a current frame from a plurality of terminals connected to the multi-access network environment;
determining a frame size of a next frame based on the number of terminals performing energy harvesting among the plurality of terminals using the collected information; and
and transmitting information on the determined frame size to the plurality of terminals. According to claim 10,
The energy harvesting is to receive energy from an access point (AP), frame size determination method. According to claim 10,
calculating an amount of energy harvested during the energy harvesting; and
A method for determining a frame size further comprising calculating an amount of energy consumed by the terminal when transmitting data. According to claim 12,
Further comprising an operation of predicting an operation to be performed by the terminal in the next frame by comparing the difference between the calculated amount of energy and a preset threshold,
Wherein the frame size is determined based on the prediction result. According to claim 10,
The frame size of the next frame is determined based on the size of the current frame. According to claim 10,
Wherein the frame size is determined using a reinforcement learning algorithm. According to claim 15,
Further comprising an operation of setting a state corresponding to each of the different frame sizes,
Wherein the frame size is determined in consideration of compensation according to transition between states. According to claim 10,
The frame size is determined based on the number of successful collision slots, the number of successful data transmission slots, and the number of idle slots among the slots included in the current frame. According to claim 10,
The method of determining the frame size, wherein the number of the plurality of connected terminals is at least partially changed for each frame. As a computer program stored on a computer-readable recording medium,
The computer program,
Including instructions for causing a processor to perform the method according to any one of claims 10 to 18
computer program. A computer-readable recording medium storing a computer program,
The recording medium,
Including instructions for causing a processor to perform the method according to any one of claims 10 to 18
A computer-readable recording medium.

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