WO2021125376A1 - Access control apparatus and method for operating same - Google Patents

Abstract

Disclosed is a network technology for establishing a point-to-multipoint (P2MP) communication smart factory by utilizing a particular wireless communication method (WiGig) having low incidence of interference .

Description

Access control device and operation method of access control device

The present invention relates to a network technology for implementing a smart factory.

More specifically, the present invention relates to a network technology for implementing a smart factory of P2MP (Point to Multi-Point) communication by utilizing a wireless communication method (eg, WiGig) having a low interference rate.

A smart factory means a factory in which a smart service environment such as precision control, predictive maintenance, cooperative robot, and flexible production is implemented with ICT (Information Communication Technology) and IoT (Internet of things) technology beyond the existing factory automation. .

In the case of such a smart factory, considering the shrinking industrial workforce, innovative growth and manufacturing innovation, it is one of the technological fields that the industry is paying the most attention in the future.

However, the factory environment in which the actual automation is implemented is mainly implemented based on the wired Internet.

Accordingly, in the current automated factory environment, when relocating a line of factory equipment, wired cable construction must be re-executed, so there are many restrictions in terms of operational cost.

In addition, since the factory environment that currently implements automation is implemented based on the wired Internet, there is a limit in that it cannot provide specific functions (eg, emergency stop, etc.) that can only be provided when the minimum delay time is guaranteed.

Of course, in order to solve the limitations and limitations due to the wired implementation, some factories are implementing a wireless communication method using 802.11 a/b/g-based Wi-Fi technology in the 2.4 GHz or 5 GHz band.

However, the frequency band of Wi-Fi (2.4 GHz or 5 GHz band) is a frequency that has been widely used in the past, and there is a problem of low usability for services such as main factory control because there is a concern about the possibility of interference between frequencies.

On the other hand, wireless communication of the WiGig method using 802.11ad as a standard uses a 60 GHz band, and has a characteristic of resonating with oxygen molecules in the air, so that the frequency characteristic has a large radio wave attenuation.

WiGig has been reviewed as a backhaul for mobile communication because the frequency band per channel is 2.16 GHz and can transmit up to 7 Gbps, but it has not been activated because the radio wave attenuation is too large and the rain attenuation is also large.

As described above, WiGig has a characteristic that the frequency characteristic of 60 GHz resonates with oxygen molecules in the air, so radio wave attenuation is severe, diffraction is relatively weak, and linearity is strong.

When such WiGig is applied to the implementation of wireless communication within a factory, the advantage of reducing the probability of causing interference during communication in the factory and the ability to transmit up to 7 Gbps per channel is expected due to the aforementioned characteristics and transmission performance of WiGig.

However, the existing WiGig type wireless communication has a limitation in that it is implemented as a 1:1 peer-to-peer method.

An object of the present invention is to provide a network technology for realizing a smart factory of P2MP (Point to Multi-Point) communication by utilizing a wireless communication method (WiGig) having a low interference rate.

Access control apparatus according to an embodiment of the present invention, each access device (Access Point) to check the candidate terminal to be a communication target candidate terminal checking unit; and a device selector for selecting two or more access devices to be used for preferential access and reconnection based on at least one of a signal direction and a signal strength, for each of the candidate terminals identified by each access device.

Specifically, each terminal as the candidate terminal first accesses the first access device having the highest signal strength among the two or more selected access devices, and when the transmission delay with the first access device is confirmed, the selected 2 Among the above access devices, it is possible to reconnect to a second access device having a higher signal strength following the first access device.

Specifically, the device selector, for each of the candidate terminals, receives the signal of the candidate terminal by using the location of the access device identified for each access device that has received the signal of the candidate terminal and the beamforming direction used when the signal is received. An angular parameter is calculated for each selectable combination of access devices among one access device, and the angular parameter of each access device combination calculated for each of the candidate terminals is calculated when two or more access devices for each of the candidate terminals are selected. can be used

Specifically, for each of the candidate terminals, the device selector may select, as the two or more access devices, an access device combination having a calculated maximum angle of arrival index from among the selectable access device combinations.

Specifically, when the device selection unit selects the two or more access devices from among the selectable access device combinations for each of the candidate terminals within a range that does not exceed the maximum number of connectable terminals set for each access device, , it is possible to select an access device combination such that the average of the angles of arrival index of the access device combinations selected for all of the candidate terminals is maximized.

Specifically, when the device selection unit selects the two or more access devices from among the selectable access device combinations for each of the candidate terminals within a range that does not exceed the maximum number of connectable terminals set for each access device, , it is possible to select a combination of access devices such that the average signal strength of the combinations of access devices selected for all the candidate terminals is maximized.

Specifically, when a specific event requiring connection re-establishment between the access device and the terminal is checked, the access device and the terminal related to the specific event are rebooted, and a candidate terminal for the rebooted access device and two or more access devices for each of the candidate terminals It may further include a reset control unit for re-performing the selection procedure.

Specifically, the access device and the terminal as the candidate terminal may be connected by using a WiGig wireless communication method using a specific frequency band having a characteristic low interference rate due to strong diffraction and strong linearity characteristics.

A method of operating an access control apparatus according to an embodiment of the present invention includes: a candidate terminal checking step of identifying a candidate terminal as a communication target in each access point; and a device selection step of selecting two or more access devices to be used for preferential access and reconnection based on at least one of a signal direction and a signal strength, for each of the candidate terminals identified in each access device.

Specifically, each terminal as the candidate terminal first accesses the first access device having the highest signal strength among the two or more selected access devices, and when the transmission delay with the first access device is confirmed, the selected 2 Among the above access devices, it is possible to reconnect to a second access device having a higher signal strength following the first access device.

Specifically, in the device selection step, for each of the candidate terminals, the signal of the candidate terminal is selected by using the location of the access device identified for each access device that has received the signal of the candidate terminal and the beamforming direction used when the signal is received. An angular parameter for each selectable combination of access devices is calculated among the received access devices, and the angle of arrival index for each combination of access devices calculated for each of the candidate terminals is selected from two or more access devices for each of the candidate terminals. can be used at

Specifically, in the device selection step, for each of the candidate terminals, an access device combination having a calculated maximum angle of arrival index among the selectable access device combinations may be selected as the two or more access devices.

Specifically, in the device selection step, within a range not exceeding the maximum number of connectable terminals set for each access device, each of the candidate terminals is selected as the two or more access devices among the selectable access device combinations. In this case, it is possible to select an access device combination such that the average of the angles of arrival index of the access device combinations selected for all the candidate terminals is maximized.

Specifically, in the device selection step, within a range not exceeding the maximum number of connectable terminals set for each access device, each of the candidate terminals is selected as the two or more access devices among the selectable access device combinations. For example, it is possible to select a combination of access devices such that the average signal strength of the combinations of access devices selected for all of the candidate terminals is maximized.

Accordingly, according to the access control device and the operating method of the access control device of the present invention, a network technology capable of P2MP (Point to Multi-Point) communication is realized by utilizing a wireless communication method (WiGig) having a low interference rate, and have.

Accordingly, if a smart factory is implemented based on the network technology realized in the present invention, the effect of improving the utility and sophistication of the smart factory is derived.

1 is an exemplary diagram showing a factory environment of a smart factory to which the present invention can be applied.

2 is an exemplary diagram showing the configuration of an access control device according to an embodiment of the present invention.

3 and 4 are exemplary views showing the concept of the angle of arrival index used in the present invention.

5 and 6 are flowcharts illustrating a method of operating an access control device according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

The present invention relates to a network technology for implementing a smart factory of P2MP (Point to Multi-Point) communication by utilizing a wireless communication method (eg, WiGig) having a low interference rate.

A smart factory means a factory in which a smart service environment such as precision control, predictive maintenance, cooperative robot, and flexible production is implemented with ICT (Information Communication Technology) and IoT (Internet of things) technology beyond the existing factory automation. .

The factory environment in which actual automation has been implemented so far has been mainly implemented based on the wired Internet.

Accordingly, in the current automated factory environment, when relocating a line of factory equipment, wired cable construction must be re-executed, so there are many restrictions in terms of operational cost.

In addition, since the factory environment that currently implements automation is implemented based on the wired Internet, there is a limit in that it cannot provide specific functions (eg, emergency stop, etc.) that can only be provided when the minimum delay time is guaranteed.

Of course, in order to solve the limitations and limitations due to the wired implementation, some factories are implementing a wireless communication method using 802.11 a/b/g-based Wi-Fi technology in the 2.4 GHz or 5 GHz band.

Wi-Fi wireless communication does not limit the number of terminals that can be accessed per AP (Access Point), and provides packet transmission in the best effort method when connecting multiple terminals, thus ensuring high-speed transmission and latency. There are downsides to not being able to.

In addition, the frequency band of Wi-Fi (2.4 GHz or 5 GHz band) is a frequency that has been widely used in the past, and there is a concern about the possibility of interference between frequencies.

On the other hand, wireless communication of the WiGig method using 802.11ad as a standard uses a 60 GHz band, and has a characteristic of resonating with oxygen molecules in the air, so that the frequency characteristic has a large radio wave attenuation.

WiGig has been reviewed as a backhaul for mobile communication because the frequency band per channel is 2.16 GHz and can transmit up to 7 Gbps, but it has not been activated because the radio wave attenuation is too large and the rain attenuation is also large.

As described above, WiGig has a characteristic that the frequency characteristic of 60 GHz resonates with oxygen molecules in the air, so radio wave attenuation is severe, diffraction is relatively weak, and linearity is strong.

When such WiGig is applied to the implementation of wireless communication within a factory, the advantage of reducing the probability of causing interference during communication in the factory and the ability to transmit up to 7 Gbps per channel is expected due to the aforementioned characteristics and transmission performance of WiGig.

However, the existing WiGig type wireless communication has a limitation in that it is implemented as a 1:1 peer-to-peer method.

If the existing WiGig implemented in the 1:1 peer-to-peer method is simply implemented in the 1:N method and applied to the smart factory implementation, high-speed transmission and delay time cannot be guaranteed like the existing Wi-Fi method. can occur

Accordingly, in the present invention, as described above, by utilizing the wireless communication method (WiGig) having a low interference generation rate, to implement a smart factory of P2MP (Point to Multi-Point) communication that can guarantee high-speed transmission and delay time. We would like to propose a network technology.

Specifically, the network technology for implementing the smart factory proposed in the present invention is to be realized through the access control device, which is a core device for implementing the network technology of the present invention.

First, with reference to FIG. 1, a factory environment of a smart factory to which the present invention can be applied will be briefly described.

As shown in Figure 1, the factory environment of the smart factory to which the present invention can be applied, the terminals (1,2, N) connected to the device to be managed in the factory (hereinafter, the factory equipment), and the wireless in the factory The access device (Access Point, AP 1, AP 2, AP N) that supports communication, the switch 10 concentrating the wired cables connected to each AP, and the remote monitoring, control and management of each plant facility It may be configured to include the server 100 .

Here, for the implementation of the network technology proposed by the present invention, it is premised that the terminals (1,2, and N) connected to each factory facility have a processor that provides one channel performance.

In addition, for the implementation of the network technology proposed in the present invention, each AP (AP 1, 2, and n) is premised on implementing a process and multi-RF channel that can be accessed in parallel by the terminal up to the maximum number of terminals (L). By doing so, communication performance (transmission speed and delay time) can be guaranteed even when a plurality of terminals are connected at the same time.

In this case, the number of terminals capable of simultaneously accessing the AP varies depending on the number of processors and the number of RF channels of the AP.

Accordingly, in the present invention, it may be assumed that the maximum number of terminals (L) for providing the AP's own optimal communication performance is set/limited in each AP (AP 1, 2, and N).

Therefore, according to the P2MP (Point to Multi-Point) communication network technology using WiGig proposed in the present invention, it is possible to access peers up to the set/limited maximum number of terminals (L) in one AP, and one A terminal can connect to one AP.

Hereinafter, with reference to FIG. 2, a configuration of a connection control device according to an embodiment of the present invention will be described.

Prior to the detailed description, the access control apparatus 200 of the present invention is based on information sharing between devices constituting the factory environment of the smart factory described above, among the devices (terminal, AP, switch, server) constituting the factory environment. It may be implemented in any one device, and may be distributed in two or more devices.

However, in the following, for convenience of explanation, the access control device 200 of the present invention is the most smoothly constructed to share information with terminals (1,2, N) and AP (AP 1, 2, and N). A case implemented in the remote server 100 will be described with reference to an embodiment.

As can be seen from FIG. 2 , the access control device 200 according to an embodiment of the present invention may include a candidate terminal checking unit 210 and a device selection unit 220 .

Furthermore, the access control apparatus 200 according to an embodiment of the present invention may further include a reset control unit 230 .

In addition, the access control apparatus 200 according to an embodiment of the present invention may further include a communication unit 240 substantially responsible for a communication function with other devices constituting the factory environment of the smart factory in addition to the above-described configuration. can

As described above, assuming that the access control device 200 is implemented in the server 100 , the communication unit 240 provides a function of communicating with each AP (AP 1, 2, and N) via the switch 10 . can be in charge

The communication unit 240 includes, for example, but not limited to, an antenna system, an RF transceiver, one or more amplifiers, a tuner, one or more oscillators, a digital signal processor, a CODEC (CODEC) chipset, and a memory, and the like. All known circuits to perform may be included.

All or at least a part of the configuration of the access control device 200 may be implemented in the form of a hardware module or a software module, or may be implemented in a form in which a hardware module and a software module are combined.

Here, the software module may be understood as, for example, a command executed by a processor that controls operations in the access control device 200 , and these commands may have a form mounted in a memory in the access control device 200 . There will be.

As a result, the access control apparatus 200 according to an embodiment of the present invention utilizes the new technology proposed by the present invention, that is, WiGig, through the above-described configuration, to ensure high-speed transmission and delay time P2MP (Point). to Multi-Point) to realize the network technology to implement a smart factory of communication.

In the case of a smart factory, frequent movement of workers or mobile robots may occur due to the unique environment of the factory.

On the other hand, 60 GHz WiGig has a weak diffraction property and a strong straight-line frequency characteristic, so that the communication performance varies greatly depending on the propagation channel environment.

Therefore, in order to implement wireless communication in a factory using WiGig, a method that can guarantee communication performance even if the channel environment is shielded due to frequent movement of a worker or a mobile robot is necessary.

Hereinafter, for realizing the network technology proposed by the present invention, in particular, the network technology using WiGig that can guarantee communication performance even when shielding in a channel environment occurs, each configuration in the access control device 200 will be described in more detail. to be explained as

The candidate terminal confirmation unit 210 plays a role of identifying a candidate terminal as a communication target in each access point.

That is, the candidate terminal check unit 210, for each AP 1, AP 2, and AP N supporting wireless communication with terminals (1,2, N) connected to each factory facility, a communication target in the corresponding AP. It is possible to check the candidate terminal with

Specifically, each of AP 1, AP 2, and AP N measures the strength of a signal transmitted by an individual terminal in the vicinity, so that the AP itself can guarantee communication quality (more than a preset strength value). A UE may be determined as a candidate UE.

At this time, in each terminal (1,2, N) and each AP (AP 1, 2, and N), an identifier that allows other devices to identify itself is previously designated, and when a signal is transmitted, this identifier is transmitted to identify its own signal. As such an identifier, a service set identifier (SSID) may be used.

Accordingly, when each AP 1, AP 2, and AP N receives a signal transmitted by the terminal, the candidate terminal may be determined based on the terminal identifier of the received signal and the measured signal strength.

When the candidate terminal check unit 210 is described again, the candidate terminal check unit 210 checks the information (eg, terminal identifier, signal strength) of the candidate terminals determined by each AP 1, AP 2, and AP N as described above. By securing it, it is possible to check the candidate terminals for communication in each of AP 1, AP 2, and AP N.

The device selection unit 220, for each of the candidate terminals identified in each access device (each AP 1, AP 2, and AP N), based on at least one of a signal direction and a signal strength to be used for preferential access and reconnection. It plays a role in selecting two or more access devices, that is, an AP.

That is, assuming that all the candidate terminals identified in each access device (each AP 1, AP 2, and AP N) are terminals (1,2, and N), the device selection unit 220, the terminal (1, 2, N), for each, two or more APs to be used for first access and reconnection are selected.

Here, the signal direction refers to a direction in which the signal is received when the terminal receives the signal in the AP.

And, the signal strength refers to the signal strength measured when the AP receives a signal from the terminal.

Furthermore, the device selection unit 220, for each of the terminals 1, 2, and N, based on the information (eg, identifier, signal strength) of the candidate terminal secured from the selected two or more APs, the signal of the terminal The AP having the largest strength may be selected as the first AP to be accessed first, and then the second AP and the third AP may be selected in the order in which the magnitude of the signal strength decreases.

Hereinafter, for convenience of description, for each of the terminals 1, 2, and N, two or more APs (hereinafter, AP pair) are selected as two or more APs will be described as an embodiment.

At this time, in the present invention, for each of the terminals 1, 2, and N, based on at least one of a signal direction and a signal strength, considering the shielding situation of the channel environment that may occur, communication performance can be guaranteed. Two or more APs, such as an AP pair, are selected.

Hereinafter, for each terminal, a process of selecting two or more APs, for example, an AP pair capable of guaranteeing communication performance, will be described in detail in consideration of the shielding situation of the channel environment.

According to an embodiment, the device selector 220, for each of the candidate terminals, that is, the terminals 1, 2, and N, the location of the AP identified for each AP receiving the signal of the terminal and the AP used when receiving the signal of the terminal. By using the beamforming direction, it is possible to calculate an angular parameter for each access device combination (hereinafter, AP combination) consisting of two selectable APs among APs that have received a signal from the terminal.

Specifically, as described above, information on candidate terminals determined and secured by each AP 1, AP 2, and AP N includes not only the terminal identifier and signal strength, but also the beamforming direction used by the AP when receiving the terminal's signal. The indicating beam identifier may be included.

In this case, the device selector 220, for each of the terminals 1, 2, and N, the location of the AP for each AP that has received the signal of the terminal and the beamforming direction (beam identifier) used by the AP when receiving the signal of the terminal By using , it is possible to calculate the angle of arrival index for all selectable AP combinations among APs that have received the terminal's signal.

For example, assuming that the APs receiving the signal from the terminal 1 are AP1, AP2, and AP3, the AP combination consisting of two APs selectable for the terminal 1 is AP 1/2, AP It can be said that there are 3 in total, 1/3 and 2/3 AP.

Accordingly, since the device selector 220 knows the location of the AP and the beamforming direction (beam identifier) used by the AP when receiving the signal of the terminal 1 for each AP 1, AP 2, and AP 3, all AP combinations, that is, For each of the three AP 1/2, AP 1/3, and AP 2/3, the angle of arrival index for the terminal 1 may be calculated using the AP position and the beamforming direction.

In this way, the device selector 220 calculates the angle of arrival index for each of the selectable AP combinations for each of the candidate terminals, that is, the terminals 1, 2, and N.

In addition, the angle of arrival index for each AP combination calculated for each of the candidate terminals, i.e., terminals (1,2, N), is when two or more APs (eg, AP pairs) are selected for each of the terminals (1,2, N). It can be used in a variety of ways.

Specifically, the device selection unit 220 selects, for each of the candidate terminals, i.e., the terminals 1, 2, and N, the AP combination having the maximum calculated angle of arrival index among the selectable AP combinations as the above-mentioned two or more APs. can be selected

For example, as described above, it is assumed that the selectable AP combinations for the terminal 1 are AP 1/2, AP 1/3, and AP 2/3, and three AP 1/2, AP 1/3, and AP It can be assumed that the AP 1/2 combination is the largest in the angle of arrival index calculated for each 2/3.

Under this assumption, the device selector 220 may select the AP combination having the maximum angle of arrival index for the terminal 1 , that is, AP 1/2 as the AP pair.

In this way, the device selector 220 may select, as an AP pair, two APs of a combination of APs having the maximum angle of arrival index for each of the candidate terminals, that is, the terminals 1, 2, and N. .

The concept of the angle of arrival index will be briefly described with reference to FIGS. 3 and 4 .

A large arrival angle index generally means that two APs are in opposite directions with respect to a terminal in a line of sight (LOS) environment, as shown in FIG. 4 .

A small arrival index generally means that two APs are in the same direction with respect to a terminal in a line of sight (LOS) environment, as shown in FIG. 3 .

Each of the terminals 1, 2, and N as candidate terminals may recognize two or more APs selected by itself, for example, an AP pair according to information sharing (eg, notification) from the access control device 200 .

Accordingly, each terminal (1,2, JN) preferentially accesses the first AP having the highest signal strength among the AP pairs selected for it, and transmission delay (speed reduction) due to shielding, etc. during communication with the first AP If this is confirmed, the connection with the first AP may be blocked and reconnection to a second AP having a higher signal strength following the first AP among the two APs previously selected by the user.

As described above, in a factory, shielding of the channel environment may occur due to frequent movement of workers or mobile robots.

Accordingly, in one embodiment of the present invention, by utilizing the concept of the angle of arrival index using the signal direction (the same as the beamforming direction at the time of signal reception) of the terminal that each AP receives, each terminal has the maximum angle of arrival index. AP pairs, that is, AP pairs located in opposite directions are selected.

For this reason, according to an embodiment of the present invention, each terminal (1,2, JN) preferentially accesses the first AP among the AP pair selected by itself, and transmits delay (speed decrease) due to shielding, etc. during communication If this is confirmed, communication is continued by reconnecting to the second AP, which is located in the opposite direction from the first AP, which is not affected by the shielding this time, so that communication performance can be guaranteed even when shielding occurs in the channel environment.

To describe a more specific embodiment, the device selection unit 220, within a range that does not exceed the maximum number of connectable terminals (L) set for each AP 1, AP 2, and AP N, the candidate terminal, that is, the terminal ( 1, 2, and N), a process of selecting the AP combination described above may be performed for each.

As described above, it may be assumed that the maximum number of terminals (L) for providing the AP's own optimal communication performance is set/limited in each AP (AP 1, 2, and N).

Accordingly, the device selection unit 220, in the process of selecting the above-described AP combination for each of the candidate terminals, that is, the terminals 1, 2, and N, the maximum number of terminals set for each AP 1, AP 2, and AP N. (L) is reflected.

Specifically, the device selection unit 220, within a range that does not exceed the maximum number of terminals (L) for each AP 1, AP 2, and AP N, each of the candidate terminals, that is, the terminals 1, 2, and N When selecting an AP pair from among the selectable AP combinations, it is possible to select an AP combination that maximizes the average of the angles of arrival of the AP combinations selected for all candidate terminals, i.e., all terminals (1,2, N).

For example, it may be assumed that the maximum number of terminals is set to 10 for each AP 1, AP 2, and AP N.

The device selector 220 has calculated the angle of arrival index for each of the selectable AP combinations for each of the terminals 1, 2, and n.

Accordingly, the device selection unit 220, within the range that does not exceed the maximum number of terminals for each AP 1, AP 2, and AP N of 10, the arrival of the AP combination for all terminals (1,2, N) An AP combination of each terminal (1,2, N) that makes each exponential average a maximum may be selected as an AP pair for each of the terminals (1,2, N).

Accordingly, in one embodiment of the present invention, the concept of the angle of arrival index using the signal direction (the same as the beamforming direction when receiving the signal) of the terminal received by each AP and limiting the maximum number of terminals (L) for each AP Using the method, the AP pair with the maximum angle of arrival index for each terminal, that is, the pair of APs located in opposite directions, is selected while maintaining the optimal communication performance for each AP.

For this reason, according to an embodiment of the present invention, each terminal (1,2, JN) can receive communication performance even when shielding of the channel environment occurs (first AP -> second AP), and any AP can be provided with optimal communication performance.

On the other hand, in the present invention, when selecting two or more APs (eg, AP pair) for each of the terminals (1,2, N), an embodiment in which the angle of arrival index is not used may be possible.

Specifically, the device selection unit 220, within a range that does not exceed the maximum number of connectable terminals (L) set for each AP 1, AP 2, and AP N, that is, the candidate terminal, that is, the terminal terminal (1,2). , N), when selecting as an AP pair among selectable AP combinations, the AP combination that maximizes the signal strength average of the AP combinations selected for all candidate terminals, i.e., all terminals (1,2, N) can be selected.

For example, it may be assumed that the maximum number of terminals is set to 10 for each AP 1, AP 2, and AP N.

The device selector 220 checks the signal strength (intensity measured when the terminal receives a signal by the AP) for each of the terminals 1, 2, and N, for all selectable AP combinations.

And, the device selection unit 220, within a range not exceeding the maximum number of terminals for each AP 1, AP 2, and AP N of 10, the signal of the combination of APs for all terminals (1,2, N) An AP combination of each terminal (1,2, N) for which the intensity average is maximized may be selected as an AP pair for each of the terminals (1,2, and N).

Accordingly, in one embodiment of the present invention, the optimal communication performance for each AP is utilized by limiting the signal strength (a parameter directly related to the channel environment) of the terminal received by each AP and the maximum number of terminals (L) for each AP. AP pair with excellent channel environment is selected for each terminal while maintaining

For this reason, according to an embodiment of the present invention, each terminal (1,2, JN) can receive communication performance even when shielding of the channel environment occurs (first AP -> second AP), and any AP can be provided with optimal communication performance.

Of course, in the present invention, the angle of arrival index using the signal strength (parameter directly related to the channel environment) of the terminal that each AP receives, and the signal direction of the terminal that each AP receives (the same as the beam forming direction when receiving the signal) By using the concept, an AP pair having the maximum average arrival angle exponential average and signal strength average for each terminal, that is, an AP pair located in opposite directions and having an excellent channel environment may be selected.

In addition, in the present invention, the signal strength (parameter directly related to the channel environment) of the terminal received by each AP, the signal direction of the terminal received by each AP (the same as the beam forming direction when receiving the signal) By utilizing the concept and method of limiting the maximum number of terminals (L) for each AP, while maintaining optimal communication performance for each AP, each terminal has an AP pair with the maximum exponential average of the arrival angle and the average signal strength, i.e., located in opposite directions. It is also possible to select an AP pair with an excellent channel environment.

As described above, according to an embodiment of the present invention, the optimal communication performance (high-speed transmission and delay time) is ensured in consideration of the occurrence of shielding in the channel environment by utilizing the wireless communication method (WiGig) having a low interference rate. It can be realized by specifying the network technology for realizing a smart factory of P2MP (Point to Multi-Point) communication.

For this reason, according to an embodiment of the present invention, compared to the implementation of a smart factory using existing WiFi, since the interference and transmission performance is excellent, it is possible to service a specific function such as an emergency stop that was not applicable due to interference and delay. possible effects can be expected.

And, according to an embodiment of the present invention, when a line relocation of a facility in a factory implemented as a smart factory, the connection between the AP and the terminal is to be optimized immediately.

To this end, the reconfiguration controller 230 may reboot the AP and the terminal related to the identified specific event when checking a specific event that requires connection re-establishment between the AP and the terminal.

In this case, with respect to the AP and the terminal rebooted by the reconnection control device 200 of the present invention (in particular, the reset control unit 230), the above-described terminal confirmation unit 210 and the device selection unit 220 are candidates for the AP. The procedure of terminal confirmation and selection of two or more APs (eg, AP pair) for each candidate terminal may be re-performed.

Here, the specific event may be defined in various ways, such as a request by a manager in the factory, deterioration of overall communication performance of the AP and the terminal in the factory, arrival of a preset reset period, and the like.

Therefore, according to an embodiment of the present invention, since the smart factory is implemented in a wireless communication method (WiGig), even when relocating a line of a factory facility, it is possible to be free from additional costs due to wired cable construction, etc. Rather, it is possible to immediately optimize the connection between the AP and the terminal to ensure optimal communication performance (high-speed transmission and delay time).

As described above, according to an embodiment of the present invention, a network technology capable of P2MP (Point to Multi-Point) communication is realized by utilizing a wireless communication method (WiGig) having a low interference rate.

Accordingly, if a smart factory is implemented based on the network technology realized in the present invention, communication performance can be guaranteed even if the channel environment is shielded, and additional costs can be generated when relocating the factory equipment line. , it derives the effect of improving the utility and advancement of the smart factory, such as being able to service specific functions such as emergency stop, which were not applicable due to interference and delay.

Hereinafter, an operating method of the access control device according to an embodiment of the present invention will be described with reference to FIGS. 3 and 6 .

First, with reference to FIG. 5, an embodiment of the method of operating the access control device of the present invention will be described.

Hereinafter, for convenience of description, the access control device 200 will be referred to and described as a subject performing the method of operating the access control device of the present invention.

In the operating method of the access control device according to an embodiment of the present invention, the access control device 200, each AP 1 supporting wireless communication with terminals (1,2, n) connected to each factory facility, For each AP 2 and AP N, a candidate terminal as a communication target in the corresponding AP may be identified (S10).

Specifically, each of AP 1, AP 2, and AP N measures the strength of a signal transmitted by an individual terminal in the vicinity, so that the AP itself can guarantee communication quality (more than a preset strength value). A UE may be determined as a candidate UE.

Accordingly, the access control device 200 secures the information (eg, terminal identifier, signal strength, beam identifier, etc.) of the candidate terminals determined by each AP 1, AP 2, and AP N as described above, so that each AP 1, Candidate terminals targeted for communication can be identified in AP 2 and AP N (S10).

And, in the operating method of the access control device according to an embodiment of the present invention, the access control device 200, for each of the candidate terminals, that is, the terminals (1,2, N) confirmed in step S10, the signal of the terminal It is possible to calculate an angular parameter for each access device combination (hereinafter, AP combination) consisting of two selectable APs among the received APs (S20).

Specifically, as described above, information on candidate terminals determined and secured by each AP 1, AP 2, and AP N includes not only the terminal identifier and signal strength, but also the beamforming direction used by the AP when receiving the terminal's signal. The indicating beam identifier may be included.

Accordingly, the access control apparatus 200 determines, for each of the terminals 1, 2, and N, the position of the AP for each AP receiving the signal from the terminal and the beam forming direction (beam identifier) used by the AP when receiving the signal from the terminal. Using this, it is possible to calculate the angle of arrival index for all selectable AP combinations among APs that have received the terminal's signal (S20).

And, in the operating method of the access control device according to an embodiment of the present invention, the access control device 200, for each of the candidate terminals, that is, the terminals (1,2, N), the AP combination calculated in step S20 By using the star angle of arrival index, an optimal combination among selectable AP combinations may be selected as two or more APs (hereinafter referred to as AP pairs) (S30).

Specifically, to describe an embodiment, the access control device 200, for each of the candidate terminals, that is, the terminals 1, 2, and N, selects the AP combination in which the calculated angle of arrival index is the maximum among selectable AP combinations. It is possible to select two or more APs, that is, an AP pair.

For example, as described above, it is assumed that the selectable AP combinations for the terminal 1 are AP 1/2, AP 1/3, and AP 2/3, and three AP 1/2, AP 1/3, and AP It can be assumed that the AP 1/2 combination is the largest in the angle of arrival index calculated for each 2/3.

Under this assumption, the access control apparatus 200 may select the AP combination having the maximum angle of arrival index for the terminal 1, that is, AP 1/2 as the AP pair.

In this way, the access control apparatus 200 may select, as an AP pair, two APs of a combination of APs having the maximum angle of arrival index for each of the candidate terminals, that is, the terminals 1, 2, and N. .

To describe a more specific embodiment, the access control device 200, within a range that does not exceed the maximum number of accessible terminals (L) set for each AP 1, AP 2, and AP N, is a candidate terminal, that is, a terminal ( 1,2, and N), when selecting as an AP pair among selectable AP combinations for each, make sure that the average of the angle of arrival index of the AP combinations selected for all candidate terminals, that is, all terminals (1,2, N) is maximized. AP combination can be selected.

For example, it may be assumed that the maximum number of terminals is set to 10 for each AP 1, AP 2, and AP N.

The access control device 200 calculates the angle of arrival index for each of the selectable AP combinations for each of the terminals 1, 2, and n in step S20.

Accordingly, the access control device 200, within the range that does not exceed the maximum number of terminals for each AP 1, AP 2, and AP N of 10, the arrival of the AP combination for the entire terminal (1,2, N) A combination of APs of each terminal (1,2, N) that makes each exponential average a maximum may be selected as an AP pair for each of the terminals (1,2, N).

On the other hand, in the operating method of the access control apparatus according to an embodiment of the present invention, the access control apparatus 200, when selecting an AP pair for each of the candidate terminals, that is, the terminals (1,2, N) in step S30, the AP The AP having the highest signal strength of the terminal in the pair may be selected as the first AP to be accessed first, and then the second AP may be selected in the order in which the signal strength decreases.

And, in the operating method of the access control device according to an embodiment of the present invention, the access control device 200, in step S30, two or more APs selected for each of the candidate terminals, that is, the terminals 1, 2, and N, that is, the AP. The pair may be notified to the corresponding terminal (S40).

Each of the terminals 1, 2, and N as candidate terminals may recognize two or more APs selected by itself, for example, an AP pair according to information sharing (eg, notification) from the access control device 200 .

Accordingly, each terminal (1,2, JN) preferentially accesses the first AP having the highest signal strength among the AP pairs selected for it, and transmission delay (speed reduction) due to shielding, etc. during communication with the first AP If this is confirmed, the connection with the first AP may be blocked and reconnection to a second AP having a higher signal strength following the first AP among the two APs previously selected by the user may be performed (S50).

As described above, in one embodiment of the present invention, the concept of the angle of arrival index using the signal direction (the same as the beam forming direction at the time of signal reception) of the terminal received by each AP and limiting the maximum number of terminals (L) for each AP Using the method, the AP pair with the maximum angle of arrival index for each terminal, that is, the pair of APs located in opposite directions, is selected while maintaining the optimal communication performance for each AP.

For this reason, according to an embodiment of the present invention, each terminal (1,2, JN) can receive communication performance even when shielding of the channel environment occurs (first AP -> second AP), and any AP can be provided with optimal communication performance.

Next, an embodiment of an operating method of the access control device of the present invention will be described with reference to FIG. 6 .

Hereinafter, for convenience of description, the access control device 200 will be referred to and described as a subject performing the method of operating the access control device of the present invention.

In the operating method of the access control device according to an embodiment of the present invention, the access control device 200, each AP 1 supporting wireless communication with terminals (1,2, n) connected to each factory facility, For each AP 2 and AP N, it is possible to check a candidate terminal as a communication target in the corresponding AP (S110).

Specifically, each of AP 1, AP 2, and AP N measures the strength of a signal transmitted by an individual terminal in the vicinity, so that the AP itself can guarantee communication quality (more than a preset strength value). A UE may be determined as a candidate UE.

Accordingly, the access control device 200 secures the information (eg, terminal identifier, signal strength, beam identifier, etc.) of the candidate terminals determined by each AP 1, AP 2, and AP N as described above, so that each AP 1, Candidate terminals targeted for communication can be identified from AP 2 and AP N (S110).

And, in the method of operating the access control apparatus according to an embodiment of the present invention, the access control apparatus 200 does not exceed the maximum number of accessible terminals (L) set for each AP 1, AP 2, and AP N. Within the range, when selecting as an AP pair among selectable AP combinations for each of the candidate terminals, namely, terminals (1,2, N) confirmed in step S10, all candidate terminals, that is, all terminals (1,2, N) It is possible to select an AP combination such that the average signal strength of the AP combination selected for is the maximum (S120).

For example, it may be assumed that the maximum number of terminals is set to 10 for each AP 1, AP 2, and AP N.

The access control device 200 checks the signal strength (intensity measured when the AP receives a signal from the terminal) for each of the selectable AP combinations for each of the terminals 1, 2, and N.

Accordingly, the access control device 200, within a range that does not exceed the maximum number of terminals for each AP 1, AP 2, and AP N of 10, the signal strength of the AP combination for all terminals (1,2, and N) A combination of APs of each terminal (1,2, N) for which the average is maximized may be selected as an AP pair for each of the terminals (1,2, and N).

On the other hand, in the operating method of the access control apparatus according to an embodiment of the present invention, the access control apparatus 200, when selecting an AP pair for each of the candidate terminals, that is, the terminals (1,2, N) in step S30, the AP The AP having the highest signal strength of the terminal in the pair may be selected as the first AP to be accessed first, and then the second AP may be selected in the order in which the signal strength decreases.

And, in the operating method of the access control device according to an embodiment of the present invention, the access control device 200, in step S30, two or more APs selected for each of the candidate terminals, that is, the terminals 1, 2, and N, that is, the AP. The pair may be notified to the corresponding terminal (S130).

Each of the terminals 1, 2, and N as candidate terminals may recognize two or more APs selected by itself, for example, an AP pair according to information sharing (eg, notification) from the access control device 200 .

Accordingly, each terminal (1,2, JN) preferentially accesses the first AP having the highest signal strength among the AP pairs selected for it, and transmission delay (speed reduction) due to shielding, etc. during communication with the first AP If this is confirmed, the connection with the first AP may be blocked and reconnection to the second AP having a higher signal strength following the first AP among the two APs previously selected by the user may be performed ( S140 ).

As described above, in one embodiment of the present invention, the optimal communication performance for each AP is utilized by limiting the signal strength (parameter directly related to the channel environment) of the terminal received by each AP and the maximum number of terminals (L) for each AP. AP pair with excellent channel environment is selected for each terminal while maintaining

For this reason, according to an embodiment of the present invention, each terminal (1,2, JN) can receive communication performance even when shielding of the channel environment occurs (first AP -> second AP), and any AP can be provided with optimal communication performance.

As described above, according to an embodiment of the present invention, a network technology capable of P2MP (Point to Multi-Point) communication is realized by utilizing a wireless communication method (WiGig) having a low interference rate.

Accordingly, if a smart factory is implemented based on the network technology realized in the present invention, communication performance can be guaranteed even if the channel environment is shielded, and additional costs can be generated when relocating the factory equipment line. , it is possible to service specific functions such as emergency stop, which were not applicable due to interference and delay, etc., resulting in the effect of improving the utility and sophistication of the smart factory.

The method of operating the access control device according to an embodiment of the present invention may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic such as floppy disks. - includes magneto-optical media, and hardware devices specially configured to store and carry out program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

Although the present invention has been described in detail with reference to various embodiments so far, the present invention is not limited to the above-described embodiments, and the technical field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims below It will be said that the technical idea of the present invention extends to the extent that any person with ordinary skill in the art can make various changes or modifications.

Claims (14)

a candidate terminal checking unit for checking a candidate terminal as a communication target in each access point; and and a device selector for selecting two or more access devices to be used for preferential access and reconnection based on at least one of a signal direction and a signal strength for each of the candidate terminals identified in each access device; . The method of claim 1, Each terminal as the candidate terminal, First access to the first access device having the largest signal strength among the two or more selected access devices, and when the transmission delay with the first access device is confirmed, reconnecting to a second access device having a higher signal strength after the first access device among the selected two or more access devices. The method of claim 1, The device selection unit For each of the candidate terminals, an access device selectable from among the access devices receiving the signal of the candidate terminal by using the location of the access device identified for each access device receiving the signal of the candidate terminal and the beamforming direction used when the signal is received Calculate the angular parameter of each combination, The access control apparatus according to claim 1, wherein the angle of arrival index for each combination of access devices calculated for each of the candidate terminals is used when selecting two or more access devices for each of the candidate terminals. 4. The method of claim 3, The device selection unit, and selecting, for each of the candidate terminals, an access device combination having a calculated maximum angle of arrival index from among the selectable access device combinations as the two or more access devices. 4. The method of claim 3, The device selection unit, Within the range that does not exceed the maximum number of connectable terminals set for each access device, For each of the candidate terminals, when selecting as the two or more access devices among the selectable combinations of access devices, an access device combination that maximizes the average of the angles of arrival of the combinations of access devices selected for all of the candidate terminals is selected. Connection control device, characterized in that. The method of claim 1, The device selection unit, Within the range that does not exceed the maximum number of connectable terminals set for each access device, For each of the candidate terminals, when selecting as the two or more access devices among the selectable access device combinations, selecting an access device combination such that the average signal strength of the combination of access devices selected for all the candidate terminals is maximized Connection control device characterized in that. The method of claim 1, When a specific event requiring connection re-establishment between the access device and the terminal is checked, the access device and the terminal related to the specific event are rebooted, and the candidate terminal for the rebooted access device is checked and the procedure of selecting two or more access devices for each of the candidate terminals Connection control device, characterized in that it further comprises a reset control unit for re-performing. The method of claim 1, The access device and the terminal as the candidate terminal, An access control device, characterized in that it is connected using a WiGig wireless communication method using a specific frequency band with a characteristic low interference rate due to strong diffraction and strong linearity characteristics. a candidate terminal checking step of identifying a candidate terminal as a communication target in each access point; and access control comprising a device selection step of selecting two or more access devices to be used for preferential access and reconnection based on at least one of a signal direction and a signal strength for each of the candidate terminals identified in each access device; How the device works. 10. The method of claim 9, Each terminal as the candidate terminal, First access to the first access device having the largest signal strength among the two or more selected access devices, and reconnecting to a second access device having a higher signal strength after the first access device among the selected two or more access devices when the transmission delay with the first access device is confirmed. 10. The method of claim 9, The device selection step is For each of the candidate terminals, an access device selectable from among the access devices receiving the signal of the candidate terminal by using the location of the access device identified for each access device receiving the signal of the candidate terminal and the beamforming direction used when the signal is received Calculate the angular parameter of each combination, The method of operating an access control device, characterized in that the angle of arrival index for each combination of access devices calculated for each of the candidate terminals is used when selecting two or more access devices for each of the candidate terminals. 12. The method of claim 11, The device selection step is The method of operating an access control device, characterized in that, for each of the candidate terminals, an access device combination having a maximum calculated angle of arrival index among the selectable access device combinations is selected as the two or more access devices. 12. The method of claim 11, The device selection step is Within the range that does not exceed the maximum number of connectable terminals set for each access device, For each of the candidate terminals, when selecting as the two or more access devices among the selectable combinations of access devices, an access device combination that maximizes the average of the angles of arrival of the combinations of access devices selected for all of the candidate terminals is selected. A method of operating a connection control device, characterized in that. 10. The method of claim 9, The device selection step is Within the range that does not exceed the maximum number of connectable terminals set for each access device, For each of the candidate terminals, when selecting as the two or more access devices among the selectable access device combinations, selecting an access device combination such that the average signal strength of the combination of access devices selected for all the candidate terminals is maximized An operating method of the access control device, characterized in that.

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