KR20190114404A - Network system and data trasmission method based on device clustering in lorawan communication - Google Patents

Abstract

The present invention relates to a LoRa communication network system based on device clustering, and a data transmission method thereof. According to one embodiment of the present invention, the LoRa communication network system comprises: an end device performing uplink and downlink data transmission through LoRa communication; a gateway transmitting a beacon message to the end device and converting a data packet received from the end device into an IP packet to broadcast the IP packet; an edge cloud connected to the gateway to control an individual connection network for the end device; and a network server managing and controlling general operation of the LoRa communication network system. Accordingly, the edge cloud monitors transmission traffic of the end device in real time to control the individual connection network for the end device, and learns characteristics of the monitored transmission traffic through an unsupervised learning algorithm, thereby grouping the end device.

Description

Rora communication network system and data transmission method based on device clustering {NETWORK SYSTEM AND DATA TRASMISSION METHOD BASED ON DEVICE CLUSTERING IN LORAWAN COMMUNICATION}

The present invention relates to a Laura communication network system and a data transmission method based on device clustering. More particularly, the present invention further includes an edge cloud for controlling individual connections of end devices in a conventional Laura communication network system. A new Laura communication network system and a data transmission method thereof.

Recent developments in the computing space have enabled intelligent services. Small devices collect and deliver data to servers on the Internet, where they analyze the data and extract information from the analysis results. This information is used for intelligent services, which are known as Internet of Things (IoT) services. Although the initial stage of the IoT service was satisfied to construct a short-range network considering only the personal area, in order to build various types of IoT services such as smart cities and smart factories, it is required to provide long-distance network services in recent years.

In response to this demand, low power wide area networks (LPWANs) are attracting attention. Among them, LoRaWAN has the advantage of communicating over 10km long distances with minimum power consumption, and is attracting more attention as an infrastructure technology for supporting the remote IoT. Conventional network systems using such Laura communication use unslotted Aloha (ALOHA), a very simple method of transmitting data frames, to transmit data frames through random access to a wireless channel.

However, the conventional Laura communication network uses a very simple transmission mechanism, as described above, so that long distance data can be transmitted even at low power, but the data rate is considerably low, and long transmission delay time is caused by long distance communication. Have

In addition, the conventional Laura communication network transmits data regardless of the characteristics of devices (devices) connected based on a random access scheme, which merely considers a collision between uplink and downlink data transmission. Therefore, if a large number of data transmissions occur at one time, the possibility of collision between data during the uplink transmission is significantly increased, and the collision between data causes a problem of increasing transmission delay and decreasing transmission efficiency.

Republic of Korea Patent Publication No. 10-1779202 (2017.09.11)

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a system and a data transmission method for efficiently transmitting data by grouping devices connected on a network system according to characteristics.

In addition, in addition to minimizing collisions between uplink transmissions and downlink transmissions during data transmission, data collisions that may occur during uplink transmissions can be minimized to enable efficient wireless channel access of prioritized devices. An object is to provide a system and a data transmission method.

According to an embodiment of the present invention, a Laura communication network system based on device clustering transmits a beacon message to an end device and an end device on which uplink data transmission and downlink data transmission are performed through Laura communication, and is received from an end device. Gateway for broadcasting and converting the data packet into IP packet, Network server for managing and controlling the overall operation of edge cloud and Laura communication network system connected to the gateway to control individual access network to the end device The edge cloud is configured to monitor the transport traffic of the end device in real time to control the individual access network to the end device, and learn the characteristics of the monitored transport traffic through an unsupervised learning algorithm, It can be grouped in a vise.

The edge cloud according to an embodiment of the present invention may classify the end devices according to the priority based on the characteristics of the transmission traffic learned through the unsupervised learning algorithm through grouping of the end devices.

According to an embodiment of the present invention, wireless channels for uplink data transmission are accessed to end devices classified according to priorities through the edge cloud, and uplink group schedule information generated in the edge cloud for access is accessed. May be piggybacked on the beacon message and sent to the end device.

According to an embodiment of the present invention, a fixed sized reception slot is used for downlink data transmission, and an end device determines a period of downlink data transmission based on a beacon message, and the period of downlink data transmission is a beacon message. It may be less than half of the period of.

An edge cloud according to an embodiment of the present invention schedules downlink data transmission for control of an individual access network to an end device, and downlink schedule information generated by the scheduling is piggybacked in a beacon message and transmitted to the end device. Can be.

In the data transmission method of the Laura communication network system based on device clustering according to an embodiment of the present invention, a beacon message is received at an end device from a gateway, and a cycle of downlink data transmission is performed at the end device based on the received beacon message. A first step that is determined, a second step where downlink data transmission is performed between the end device and the gateway according to the determined period of the downlink data transmission, the end device in an edge cloud connected to the gateway to control an individual access network to the end device. Monitoring the transport traffic in real time and learning the characteristics of the monitored transport traffic through an unsupervised learning algorithm, thereby grouping the end devices and the end device and gateway based on the grouping of the end devices. Between may include a fourth step which uplink data transmission is performed.

According to an embodiment of the present invention, in the third step, the end devices may be classified according to priority based on the characteristics of the transmission traffic learned through the unsupervised learning algorithm in the edge cloud.

According to an embodiment of the present invention, in the fourth step, a wireless channel for uplink data transmission is accessed to the end devices classified according to the priorities through the edge cloud, and is created in the edge cloud for access. The uplink group schedule information may be piggybacked in the beacon message and transmitted to the end device.

According to an embodiment of the present invention, in the second step, a fixed sized reception slot is used for downlink data transmission, and the period of the downlink data transmission may be less than half of the period of the beacon message.

According to an embodiment of the present invention, in a first step, downlink data transmission is scheduled for control of an individual access network to an end device in an edge cloud, and downlink schedule information generated by the scheduling is piggybacked in a beacon message. And can be sent to the end device.

Meanwhile, according to an embodiment of the present invention, a computer-readable recording medium having recorded thereon a program for executing the above-described method on a computer can be provided.

According to the Laura communication network system and its data transmission method provided as an embodiment of the present invention, by performing data transmission in consideration of the characteristics of the device connected on the system, retry due to transmission failure (ex. Data collision, etc.) The transmission delay can be prevented from increasing exponentially. That is, the efficiency of data transmission can be greatly improved compared with the prior art.

In addition, according to the Laura communication network system and a data transmission method provided according to an embodiment of the present invention, by reducing the possibility of transmission failure by adjusting the wireless channel access of the device according to the priority in the uplink transmission, the device by retransmission Since the energy consumption can be lowered, energy efficiency in data transmission can be greatly improved as compared with the conventional method.

1 is a flowchart illustrating an example of a conventional Laura communication network system.
2 shows an example of a data transmission scheme in a conventional Laura communication network system.
3 is a block diagram illustrating a Laura communication network system based on device clustering according to an embodiment of the present invention.
4 is a block diagram illustrating an uplink data transmission process of a Laura communication network system according to an embodiment of the present invention.
5 illustrates downlink data transmission and uplink data transmission periods according to a period of a beacon message in a Laura communication network system according to an embodiment of the present invention.
6 is a block diagram illustrating a downlink data transmission process of a Laura communication network system according to an embodiment of the present invention.
7 is a graph illustrating a result of comparing data collision probabilities between a Laura communication network system and a conventional Laura communication network system according to an embodiment of the present invention, and (b) Laura communication according to an embodiment of the present invention. A graph showing data collision probability by end device group of a network system.
8 is a graph illustrating a result of comparing an average transmission delay between a Laura communication network system and a conventional Laura communication network system according to an embodiment of the present invention, and (b) Laura communication according to an embodiment of the present invention. It is a graph showing the result of comparing the traffic amount of the uplink transmission between the network system and the conventional Laura communication network system.
9 is a flowchart illustrating a data transmission method of a Laura communication network system based on device clustering according to an embodiment of the present invention.

Terms used herein will be briefly described and the present invention will be described in detail.

The terms used in the present invention have been selected as widely used general terms as possible in consideration of the functions in the present invention, but this may vary according to the intention or precedent of the person skilled in the art, the emergence of new technologies, and the like. In addition, in certain cases, there is also a term arbitrarily selected by the applicant, in which case the meaning will be described in detail in the description of the invention. Therefore, the terms used in the present invention should be defined based on the meanings of the terms and the contents throughout the present invention, rather than the names of the simple terms.

When any part of the specification is to "include" any component, this means that it may further include other components, except to exclude other components unless otherwise stated. In addition, terms such as "... unit" described in the specification means a unit for processing at least one function or operation, which may be implemented in hardware or software, or a combination of hardware and software.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart illustrating an example of a conventional Laura communication network system, and FIG. 2 shows an example of a data transmission scheme in a conventional Laura communication network system.

Referring to FIG. 1, a conventional Laura communication network system is composed of an IoT device 1, a gateway 2, and a network server 3. In the wireless area, the network consists of a single hop star topology centered on the gateway 2, and the gateway 2 and the IoT device 1 transmit and receive data through LPWAN wireless. do. In the wired area, the gateway 2 is connected with the network server 2. The network server 2 manages elements on the network such as the IoT device 1 using the LPWAN manager function, and the gateway 2 transfers the data received from the IoT device 1 to the network server 3. Perform the function. The IoT device 1 collects information and performs operations under the control of the network server 3 using the LPWAN function.

Since the conventional Laura communication network system performs data transmission through a very simple transmission mechanism, all IoT devices 1 connected on the network have access to the wireless channel with the same opportunity during data frame transmission, and in the process A collision occurs and a problem arises in that the transmission delay time becomes long.

2 (a) and 2 (b) show a data transmission process between the gateway 2 and the device 1 by a class A, which is one of data transmission types of Laura communication. Laura communication basically allows bidirectional communication on the uplink and downlink. Slotted Aloha (ALOHA) is used for data transmission between the device 1 and the gateway 2.

2 (a) shows a process of transmitting uplink data of class A. Referring to (a) of FIG. 2, in class A, two reception windows are generated during each uplink transmission from the device. The downlink transmission from the network server 3 takes place in the reception window after the uplink transmission in the device 1. The receiving window is opened after the RECEIVE_DELAY1 time and the RECEIVE_DELAY2 time (i.e. longer than the RECEIVE_DELAY1 time), respectively. That is, even when the device 1 is ready to send another data (i.e. when another uplink data transmission is ready), the data cannot be sent immediately, and the reception window must wait for reception of the downlink data.

2B illustrates a downlink data transmission process of class A. FIG. For downlink data transmission, the device 1 requests the downlink data to the gateway 2 by sending an unconfirmed data message. When the request is performed in this way, the reception window is opened in the device 1 and downlink data is transmitted.

2 (c) shows a data transmission process between the gateway 2 and the device 1 by the class B, which is one of the data transmission types of the Laura communication. The device 1 may request to switch the data transfer type to class B through a class A Laura application. In class B, data transmission is performed through a gateway 2 that broadcasts a beacon. The beacon message delivered through the gateway 2 synchronizes the device 1 of the Laura communication network. The device 1 receiving the beacon message may use the reception window as a periodic time slot. Downlink data transmission occurs in the assigned receive window. Device 1 of class B periodically receives a beacon message, and if not, returns to class A.

Referring to FIG. 2C, in class B, the device 1 schedules a beacon slot and a reception slot. The beacon message is sent in the beacon slot, and the downlink data message is sent from the gateway 2 to the device along the scheduled slot as a receive window. In this case, the uplink data message may be transmitted avoiding the scheduled beacon slot and the reception slot.

The above-described Laura data transmission of Class A and Class B methods is based on a random access method. Therefore, data is transmitted regardless of the characteristics of the device 1 connected on the network system, and only the collision between the uplink and downlink data transmission is considered. That is, in the conventional Laura communication network system using this method, when several devices 1 are connected, a collision between data occurs during uplink data transmission, and thus there is a problem that transmission efficiency is inevitably reduced.

3 is a block diagram illustrating a Laura communication network system based on device clustering according to an embodiment of the present invention.

Referring to FIG. 3, a Laura communication network system based on device clustering according to an embodiment of the present invention includes an end device 100 and an end device 100 in which uplink data transmission and downlink data transmission are performed through Laura communication. Gateway 200 for transmitting a beacon message, and converting the data packet received from the end device 100 into an IP packet for broadcast, and connected to the gateway 200 to an individual device for the end device 100. An edge cloud 300 for controlling the access network and a network server 400 for managing and controlling the overall operation of the Laura communication network system, the edge cloud 300 is a separate access network for the end device 100 In order to control the transmission traffic of the end device 100 in real time, By learning the characteristics through an unsupervised learning algorithm, the end devices 100 can be grouped.

At this time, the end device 100 according to an embodiment of the present invention refers to a device capable of connecting to a wireless network so that an IoT service can be provided. For example, the end device 100 may be a smartphone, a tablet PC, a smart TV, an artificial intelligence speaker, a smart car, and the like, but is not limited thereto and may include all devices capable of driving an application for an IoT service.

The gateway 200 according to an embodiment of the present invention transmits a beacon message to the end device 100 because the gateway 200 performs data transmission based on the class B of the data transmission type of the Laura communication. That is, to ensure downlink data transmission, the gateway 200 may transmit a beacon message including a control command of the network server 400 or the edge cloud 300 to the end device 100 based on the class B. Specific details of the present invention related to class B based downlink and uplink data transmission (ie, downlink and uplink slots allocated on the network according to beacon periods, etc.) will be described below with reference to FIGS. 5 and 6 below. do.

1 and 3, unlike the conventional Laura communication network system, it can be seen that the Laura communication network system according to an embodiment of the present invention further includes an edge cloud 300. Conventionally, the network server 400 performs uplink or downlink data transmission and management of all devices connected on the system, but this causes problems such as data transmission conflicts as described above. Accordingly, the Laura communication network system according to an embodiment of the present invention includes an edge cloud 300 to control wireless channel access for data transmission of devices connected to the gateway 200. The edge cloud 300 may be formed on the system by being connected to each individual gateway 200, and may provide computing resources to the end device 100 that lacks resources.

In addition, the edge cloud 300 according to an embodiment of the present invention monitors the transmission traffic of the end device 100 in real time to control the individual access network to the end device 100, the characteristics of the monitored transmission traffic By learning through the unsupervised learning algorithm, the end devices 100 can be grouped. The detailed control method of the uplink and downlink data transmission through the edge cloud 300 (i.e. grouping of the learning and end devices 100 through the unsupervised learning algorithm) will be described later with reference to FIGS. 4 to 6.

4 is a block diagram illustrating an uplink data transmission process of a Laura communication network system according to an embodiment of the present invention, and FIG. 5 is a downlink according to a cycle of a beacon message in a Laura communication network system according to an embodiment of the present invention. Link data transmission and uplink data transmission cycles are shown.

Referring to FIG. 4, the edge cloud 300 according to an embodiment of the present invention may select the end device 100 based on the characteristics of the transport traffic learned through the unsupervised learning algorithm through grouping of the end devices 100. You can sort by priority.

In this case, the unsupervised learning algorithm used to learn the characteristics of the transport traffic of the end device 100 in the edge cloud 300 may be a k-means clustering algorithm. The k-means clustering algorithm is one of the self-learning algorithms for the case where the number of groups is not predetermined. Referring to Table 1 below, which represents the k-means clustering algorithm, the cluster centroids (μ _j ) for the grouping are first selected in the k-means clustering algorithm. Cluster center refers to the expected center point of each group. The cluster center refers to k samples of training examples (X ⁽ⁱ⁾ ) and is chosen randomly. When the cluster center is selected, the frequency of data generation between the cluster center and the training sample data and the Euclidian distance of the data characteristics are calculated for each training sample data. And, the cluster center having the minimum Euclidean distance for each learning example data is assigned to the learning example. That is, each learning data is grouped based on the nearest cluster center. The cluster center is then updated to mean the cluster center value assigned to the learning example. Euclidean distance calculations and cluster-centric updates are repeated until convergence, which results in an end device group.

TABLE 1

Through the learning process of the transmission traffic characteristic through the non-supervised learning algorithm as described above, the grouping of the end devices 100 may be performed and the priority of data transmission may be assigned for each end device 100. That is, in the edge cloud 300, the end device 100 is assigned to the priority of data transmission through grouping of the end devices 100 connected to the gateway 200 in order to efficiently control the individual access networks of the end devices 100. Can be classified accordingly.

4 and 5, a wireless channel for uplink data transmission is accessed through the edge cloud 300 according to an embodiment of the present invention to the end devices 100 classified according to priority. The uplink group schedule information generated in the edge cloud 300 for access may be piggybacked in a beacon message and transmitted to the end device 100.

When the end device 100 attempts to secure a wireless channel at the same time during the uplink data transmission, collisions may be avoided, so that the edge device 300 may use an end device (i.e., to minimize the collision by increasing data transmission efficiency and wireless channel utilization). 100) The wireless channel may be accessed according to the priority of each group. In this case, a higher order for access may be assigned to an end device group having a higher priority among the end device groups. In other words, the wireless channels are accessed in the highest order to the end device group having the highest average priority of the end devices 100 constituting the group, and the data transmission time for the end device group having the highest average priority is the uplink period. Can be assigned to the beginning of the.

For example, referring to FIGS. 4 and 5, when the end device 100 is grouped into an end device group A 110, an end device group B 120, an end device group C 130, or the like, the average priority is given. Group A 110, which has the highest rank, is assigned to the first of the uplink data transmission period, and second highest group B 120 is assigned to the second and third highest group C 130 of the uplink data transmission period. Can be assigned to the third of a period. Each end device group may access a wireless channel in accordance with an allocated uplink data transmission period, and perform uplink data transmission to the gateway 200.

As such, the uplink data transmission period (transmission time) allocated for each end device group is scheduled by the edge cloud 300, and the uplink group schedule information generated through the scheduling is together with the beacon message transmitted from the gateway 200. It is piggybacked and delivered to the end device 100 periodically. The end device 100 may perform uplink data transmission according to the allocated uplink period based on the received uplink group schedule information.

If the end device 100 cannot perform uplink data transmission due to a problem such as a data transmission collision between the end devices 100 in the end device group, a backoff, a failure in acquiring a wireless channel, and the like, the end device 100 May transmit uplink data (or messages) in the downlink period of the next data frame. That is, since the end device 100 must respond to downlink data reception by transmitting a response message to the gateway 200 during downlink data transmission, the uplink data that is not transmitted in the previous frame (cycle) in the end device 100. If there is (or a message), uplink data (or message) not transmitted in the previous frame (period) may be piggybacked along with the response message in the downlink period and transmitted to the gateway 200.

Referring to FIG. 5, according to an embodiment of the present invention, a reception slot having a fixed size is used for downlink data transmission, and the end device 100 determines a period of downlink data transmission based on a beacon message. The period of downlink data transmission may be less than half the period of the beacon message.

For example, referring to FIG. 5, downlink slots on the network may be located after the beacon slots with a fixed size receive slot (RCV_SLOT) and down depending on the number of end devices 100 receiving the beacon message. The size of the link slot (ie, the period of downlink data transmission) may be variably determined. However, for the fairness of downlink data transmission and uplink data transmission, the entire downlink slot should not exceed half of the period of the beacon message. Thus, the period of downlink data transmission may be less than half the period of the beacon message.

6 is a block diagram illustrating a downlink data transmission process of a Laura communication network system according to an embodiment of the present invention.

Referring to FIG. 6, the edge cloud 300 according to an embodiment of the present invention schedules downlink data transmission for control of an individual access network to the end device 100, and generates a downlink schedule generated by the scheduling. The information may be piggybacked in the beacon message and transmitted to the end device 100.

That is, since the gateway 200 according to an embodiment of the present invention performs data transmission based on class B, the downlink schedule information generated in the edge cloud 300 is scheduled in the beacon message to schedule downlink data transmission. It may be piggybacked and transmitted to the end device 100. In addition, a control command for managing the data transmission operation of the entire system generated by the network server 400 may also be piggybacked in the beacon message and transmitted to the end device 100. Downlink schedule information, a control command, and the like piggybacked in a beacon message periodically transmitted from the gateway 200 to the end device 100 may be received and recognized by the end device, and the end device may be recognized according to the recognized information and command. An operation such as uplink or downlink data transmission of 100 may be performed.

7 is a graph illustrating a result of comparing data collision probabilities between a Laura communication network system and a conventional Laura communication network system according to an embodiment of the present invention, and (b) Laura communication according to an embodiment of the present invention. A graph showing data collision probabilities for each end device group of a network system.

8 is a graph illustrating a result of comparing an average transmission delay between a Laura communication network system according to an embodiment of the present invention and a conventional Laura communication network system, and (b) according to an embodiment of the present invention. A graph showing a result of comparing traffic amounts of uplink transmission between a Laura communication network system and a conventional Laura communication network system.

7 and 8 are based on simulation results of evaluating performance of data transmission in a conventional Laura communication network system and data transmission in a Laura communication network system according to an embodiment of the present invention.

<Performance evaluation environment>

Performance evaluation was performed by computer simulation and implemented in C language using SMPL library. Performance evaluation of the proposed data transmission method according to an embodiment of the present invention was performed by comparing with class A and class B in the conventional Laura communication. Class A used pure ALOHA for data transmission and the reception delay was set to 1 second. According to an embodiment of the present invention, the reception slot size for downlink transmission is 5 seconds, and the number of end devices 100 performing downlink transmission is a period of a beacon message. Randomly selected from 1 to 10 per time. At this time, the period of the beacon message was set to 125 seconds.

According to an embodiment of the present invention, the proposed data transmission method assumes three types of end device groups, and the three types of end device groups have Poissons having different arrival rates of 0.004, 0.002, and 0.001, respectively. poisson) to generate data. Each end device group was distributed at a ratio of 5: 3: 2, the size of the data was set to 250 bytes, and the simulation was performed up to 1000 beacon cycles.

<Performance matrix>

As the performance matrix for the performance evaluation, the collision probability, the expected transmission delay, and the expected value of the successfully transmitted data in the wireless channel are used, and each matrix can be estimated as follows.

Collision probability

When data is generated in a Poisson distribution in a wireless channel, the data generation probability in the channel may be expressed as in Equation 1 below.

[Equation 1]

In Equation 1, X is a random variable representing data at time t, and n is the number of data in the wireless channel. In this case, given an arrival rate (λ), the data generation probability may be represented by an exponential function.

Since a collision occurs when several transmissions are attempted on a radio channel, a successful data transmission probability is used to obtain a collision probability. This is represented by Equation 2 as a random variable X having no data in the wireless channel.

[Equation 2]

Then, the collision probability may be expressed as in Equation 3 below.

[Equation 3]

As can be seen from Equation 3, the collision probability depends on the arrival rate of the input data in the radio channel.

Expected transmission delay

As mentioned above, dedicated slots are used for downlink transmission on the network. Dedicated slots are not used in uplink transmissions as in downlink transmissions, but assume that as much time as downlink slot size is required until data is transmitted and an acknowledgment is received. In addition, it is assumed that if a collision occurs, retransmission is attempted at most twice, and retransmission is performed after random backoff. Then, the expected transmission delay can be expressed using collision probability as shown in [Equation 4].

[Equation 4]

At this time, T _S is assumed to be 5 seconds as a successfully transmitted time. T _BO represents the backoff time and is randomly determined from the remaining uplink transmission time. r means the number of retransmission attempts.

Expected value of successfully transmitted data

The collision probability can be used to obtain the expected value of the successfully transmitted data. When retransmission is considered, the expected value of successfully transmitted data may be expressed as shown in Equation 5 below.

[Equation 5]

Here, BYTE means the size of data, and the amount of data received from the network server can be estimated through [Equation 5].

<Simulation Result>

The results evaluated using the performance matrix described above are as follows.

Referring to (a) and (b) of FIG. 7, it can be seen that the proposed data transmission method has the lowest collision probability according to an embodiment of the present invention. It can be seen that class A represents the highest collision probability, since it performs uplink and downlink data transmission on the same radio channel. In contrast, Class B divides the wireless channel into downlink and uplink, so there is no conflict between downlink and uplink transmissions. However, since collision occurs when each end device 100 transmits data in the uplink transmission period, it can be seen that the collision probability is higher than that of the proposed data transmission method according to an embodiment of the present invention.

In the Laura communication network system according to an embodiment of the present invention, since the transmission period is provided for each group according to the priority of the end device 100, the collision probability may be significantly reduced in comparison with the class A and the class B.

Referring to FIG. 8 (a), it can be seen that the proposed data transmission method according to an embodiment of the present invention shows the shortest transmission delay compared to class A and class B. It can be seen that the average transmission delay graph is similar to the collision probability graph because the transmission delay due to retransmission increases as the probability of collision increases.

In LPWAN, where resources are scarce, collisions must be minimized for reliable data transmission. If data needs to be transmitted over long distances at low power and low speed, complex data transfer techniques that require many message exchanges cannot be applied. In other words, the data transmission technique in Laura communication should be simple and effective. Therefore, as can be seen from the results shown in FIGS. 7 and 8 (a), using the Laura communication network system according to an embodiment of the present invention significantly reduces the possibility of collision, and effectively transmits long distance data at low power and low speed. Can be performed.

8 (b) shows the amount of traffic of the uplink transmission expected based on the collision probability. At this time, the amount of uplink bytes on the Y-axis means the expected data value successfully transmitted from the server. In class A, the transmission success rate is very low because uplink and downlink data transmissions occur at the same time and the collision probability is high. According to the class B and the proposed data transmission scheme according to an embodiment of the present invention, the transmission success rate can be increased by separating the uplink and the downlink transmission to avoid collision between the uplink and the downlink. According to an embodiment of the present invention, the proposed data transmission scheme can also reduce the collision probability in uplink data transmission, and thus, it can be seen that the expected value of successfully transmitted data is larger than that of Class B as time passes. .

As described above with reference to FIGS. 7 and 8, a data transmission scheme in a Laura communication network system according to an embodiment of the present invention has a collision probability and a transmission delay compared to Class A and Class B in a conventional Laura communication network system. In addition, it can be seen that the performance is improved significantly in the indicators such as expected data transmitted successfully. That is, by reducing the collision between data transmission of the end device 100 through the Laura communication network system according to an embodiment of the present invention, the efficiency of data transmission can be greatly improved compared to the conventional.

9 is a flowchart illustrating a data transmission method of a Laura communication network system based on device clustering according to an embodiment of the present invention.

Referring to FIG. 9, in the data transmission method of the Laura communication network system based on device clustering according to an embodiment of the present disclosure, a beacon message is received at the end device 100 from the gateway 200, and the received beacon message is received. The first step (S100) in which the period of the downlink data transmission is determined in the end device 100, the downlink data transmission is performed between the end device 100 and the gateway 200 according to the determined period of the downlink data transmission In the second step (S200), the edge cloud 300 connected to the gateway 200 to control the individual access network to the end device 100 in real time to monitor the transmission traffic of the end device 100, the monitored A third step of grouping the end devices 100 by learning characteristics of the transmission traffic through an unsupervised learning algorithm (S300). And a fourth step S400 in which uplink data transmission is performed between the end device 100 and the gateway 200 based on the grouping of the end device 100.

According to an embodiment of the present invention, in the third step S300, the end device 100 may be classified according to priority based on the characteristics of the transport traffic learned through the unsupervised learning algorithm in the edge cloud 300. have.

According to an embodiment of the present invention, in the fourth step S400, a wireless channel for uplink data transmission is accessed to the end devices 100 classified according to priority through the edge cloud 300. The uplink group schedule information generated in the edge cloud 300 for access may be piggybacked in a beacon message and transmitted to the end device 100.

According to an embodiment of the present invention, in a second step (S200), a reception slot having a fixed size is used for downlink data transmission, and the period of the downlink data transmission may be less than half of the period of the beacon message.

According to an embodiment of the present invention, in the first step S100, the downlink data transmission is scheduled for control of an individual access network to the end device 100 in the edge cloud 300, and the downlink generated by the scheduling is generated. The link schedule information may be piggybacked in the beacon message and transmitted to the end device 100.

With regard to the method according to an embodiment of the present invention, the above description may be applied. Therefore, with respect to the method, the same content as that for the above-described system has been omitted.

Meanwhile, according to an embodiment of the present invention, a computer-readable recording medium having recorded thereon a program for executing the above-described method on a computer can be provided. In other words, the above-described method can be written as a program that can be executed in a computer, and can be implemented in a general-purpose digital computer for operating the program using a computer readable medium. In addition, the structure of the data used in the above-described method can be recorded on the computer-readable medium through various means. A recording medium for recording an executable computer program or code for performing various methods of the present invention should not be understood to include temporary objects, such as carrier waves or signals. The computer readable medium may include a storage medium such as a magnetic storage medium (eg, a ROM, a floppy disk, a hard disk, etc.), an optical reading medium (eg, a CD-ROM, a DVD, etc.).

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. .

100: end device 110: end device group A
120: end device group B 130: end device group C
200: gateway 300: edge cloud
400: network server

Claims (11)

In a Laura communication network system based on device clustering,
An end device on which uplink data transmission and downlink data transmission are performed via Laura communication;
A gateway for transmitting a beacon message to the end device, and converting the data packet received from the end device into an IP packet for broadcast;
An edge cloud connected to the gateway to control an individual access network for the end device; And
It includes a network server for managing and controlling the overall operation of the Laura communication network system,
The edge cloud groups the end devices by monitoring the transport traffic of the end device in real time to control the individual access network to the end device and learning the characteristics of the monitored transport traffic through an unsupervised learning algorithm. Laura communication network system, characterized in that.
The method of claim 1,
And the edge cloud classifies the end devices according to priority based on characteristics of the transmission traffic learned through the unsupervised learning algorithm through grouping of the end devices.
The method of claim 2,
A wireless channel for transmitting the uplink data is accessed to the end devices classified according to the priority through the edge cloud,
The uplink group schedule information generated in the edge cloud for the access is piggybacked to the beacon message and transmitted to the end device.
The method of claim 1,
The downlink data transmission uses a fixed size reception slot,
The end device determines a period of the downlink data transmission based on the beacon message,
Wherein the period of the downlink data transmission is less than half the period of the beacon message.
The method of claim 1,
The edge cloud schedules the downlink data transmission for control of an individual access network to the end device,
The downlink schedule information generated by the scheduling is piggybacked in the beacon message and transmitted to the end device.
A data transmission method of a Laura communication network system based on device clustering,
Receiving a beacon message at an end device from a gateway and determining a period of downlink data transmission at the end device based on the received beacon message;
A second step of performing downlink data transmission between the end device and the gateway according to the determined period of the downlink data transmission;
By monitoring the transport traffic of the end device in real time in an edge cloud connected to the gateway to control the individual access network to the end device, and learning the characteristics of the monitored transport traffic through an unsupervised learning algorithm, A third step of grouping devices; And
And a fourth step of performing uplink data transmission between the end device and the gateway based on the grouping of the end devices.
The method of claim 6,
In the third step, the end device is classified according to priority based on the characteristics of the transmission traffic learned through the unsupervised learning algorithm in the edge cloud.
The method of claim 7, wherein
In the fourth step, the wireless channel for transmitting the uplink data is accessed to the end devices classified according to the priority through the edge cloud,
The uplink group schedule information generated in the edge cloud for the access is piggybacked to the beacon message and transmitted to the end device.
The method of claim 6,
In the second step, a fixed sized reception slot is used for the downlink data transmission.
And the period of the downlink data transmission is less than half of the period of the beacon message.
The method of claim 6,
In the first step, the downlink data transmission is scheduled for control of an individual access network to the end device in the edge cloud,
The downlink schedule information generated by the scheduling is piggybacked in the beacon message and transmitted to the end device.
A computer-readable recording medium having recorded thereon a program for implementing the method of any one of claims 6 to 10.

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