KR101687195B1 - Wireless communication apparatus and method for controlling thereof - Google Patents

Abstract

The present invention relates to a wireless communication apparatus and a control method thereof, and more specifically, includes a technique about a coping method of each wireless communication apparatus when a wireless communication terminal connecting to a predetermined access point (AP) is moved to other AP. According to one embodiment of the present invention, an AP communicating with the wireless communication terminal comprises: a transmitting/receiving unit transmitting and receiving a wireless signal; and a processor to control operation of the transmitting/receiving unit. The processor transmits a validity confirmation signal to confirm whether the wireless communication terminal can perform communications to the wireless computer terminal through the transmitting/receiving unit, and disassociates the wireless communication terminal when an acknowledge signal with respect to the validity confirmation signal is not received. Disassociation including collection of association ID (AID) allocated to the wireless communication terminal and removal of information relating to the wireless communication terminal.

Description

[0001] WIRELESS COMMUNICATION APPARATUS AND METHOD FOR CONTROLLING THEREOF [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication apparatus and a control method thereof, and more particularly, to a wireless communication apparatus connected to a specific access point.

Recently, as the spread of mobile devices has widened, wireless LAN technology capable of providing fast wireless Internet service to a large number of people has received much attention. Wireless LAN technology is a technology that allows wireless devices such as smart phones, smart pads, laptop computers, portable multimedia players, and embedded devices to wirelessly access the Internet based on wireless communication technology in close range.

STAs of a wireless LAN perform scanning, authentication, and association to access the Internet through an access point (AP). The search is a procedure for discovering accessible access points. The search procedure can be divided into manual search and active search. It is passive scanning to find a connectable access point by listening to a beacon transmitted periodically by a broadcasting station in the form of a broadcast message, and the terminal transmits a probe request on a specific channel And receiving the probe response transmitted through the specific channel by the receiving access point to find an accessible AP is active scanning. The searching, authentication and combining processes performed by the terminals with the access point are referred to as network connection procedures. A DHCP (Dynamic Host Configuration Protocol) procedure for receiving an IP address may be performed separately from the network connection procedure.

Since the wireless LAN does not support handover when changing the access point to which the terminal is connected, the wireless LAN must perform a new communication procedure by performing a new network access procedure with the new access point. That is, since the wireless LAN is not supported for handover, when the wireless communication terminal moves between the access points, communication disconnection occurs in the terminal, and it is difficult for the access point to manage the connection of the terminal and the terminal .

An object of the present invention is to provide a method for efficiently managing connection of a wireless communication terminal that moves between access points in a wireless LAN that does not support handover.

According to an embodiment of the present invention, there is provided a wireless communication system including: a transceiver for transmitting and receiving a radio signal in an access point communicating with a wireless communication terminal; And a processor for controlling the operation of the transceiver, wherein the processor transmits a validation confirmation signal for confirming whether or not the wireless communication terminal is capable of communicating with the wireless communication terminal through the transceiver, Disassociates the wireless communication terminal from the wireless communication terminal if an ACK signal for the wireless communication terminal is not received, and the connection release includes a collection of an AID (Association ID) assigned to the wireless communication terminal and deletion of information related to the wireless communication terminal The access point can be provided.

The processor transmits the validation confirmation signal to the wireless communication terminal through the transceiver when the wireless communication terminal can not transmit or receive a wireless signal with the wireless communication terminal for a predetermined period of time or longer through the transceiver.

Wherein the processor transmits the validation confirmation signal to the wireless communication terminal through the transceiver unit according to a predetermined period.

Here, when the number of wireless communication terminals communicating with the access point exceeds a predetermined maximum number of terminals, the processor starts the progress of the period.

Here, the processor may transmit the validation confirmation signal to at least a part of the plurality of wireless communication terminals based on the order in which a plurality of wireless communication terminals including the wireless communication terminal are connected to the access point through the transceiving unit send.

Here, with respect to a plurality of wireless communication terminals including the wireless communication terminal, the processor is configured to transmit, via the transmission / reception unit, the plurality of wireless communication terminals based on the order of the plurality of wireless communication terminals, And transmits the validation acknowledgment signal to at least a part of the terminals.

Here, if the number of the wireless communication terminals connected to the access point is equal to or greater than a preset inspection start threshold value, the processor transmits the validation confirmation signal to the wireless communication terminal through the transceiver, The transmission of the validation acknowledgment signal is stopped if the number is less than a preset inspection termination threshold value.

When the wireless communication terminal receives a notification signal indicating that the wireless communication terminal has connected to another access point from an access controller that manages a wireless communication network including the access point through the transceiver, And transmits the validation confirmation signal to the wireless communication terminal through the transmission / reception unit.

Here, the announcement signal may be transmitted to the wireless communication terminal after the wireless communication terminal is connected to the access point, after the wireless communication terminal or the access point transmits the connection fact to the connection controller, If the wireless communication terminal or the other access point transmits the connection information to the access controller, the access controller transmits the connection information to the access point.

Here, the validity confirmation signal is one of a Ready to Send (RTS) packet, an ARP Request (Address Resolution Protocol Request) packet, and a null data packet, and the ACK signal for the validity check signal is CTS to-send packet or an ARP reply packet, and the RTS packet and the duration field of the CTS packet are set as time values for transmission and reception of the RTS packet and the CTS packet.

According to another embodiment of the present invention, there is provided a control method of an access point, comprising: transmitting a validation confirmation signal for confirming whether or not the wireless communication terminal can communicate with a wireless communication terminal; And

And disassociating the connection with the wireless communication terminal if an ACK signal for the validation signal is not received, wherein the disconnection includes a number of AIDs allocated to the wireless communication terminal, And the deletion of the terminal-related information.

According to another embodiment of the present invention, there is provided a wireless communication terminal for performing communication with an access point, comprising: a transceiver for transmitting and receiving a radio signal; And a processor for controlling operation of the transceiver, wherein the processor receives a signal for confirming the validity of the radio communication terminal from the access point through the transceiver, and outputs an ACK signal for confirming the validity Wherein the signal for confirming the validity is a signal for confirming whether or not the access point can communicate with the wireless communication terminal.

According to another embodiment of the present invention, there is provided an access controller for managing a wireless communication network, comprising: a transmitting / receiving unit for transmitting / receiving a wireless signal or a wired signal; And a processor for controlling operation of the transceiver, wherein the processor receives a signal from the wireless communication terminal or the first access point via the transceiver to indicate that the wireless communication terminal is connected to the first access point, And a second access point for receiving a signal indicating that the wireless communication terminal is connected to the second access point from the wireless communication terminal or the second access point through the transceiver, The first access point transmits a notification signal indicating that the wireless communication terminal is connected to the second access point, and the first access point transmits a validation confirmation signal for confirming whether or not the wireless communication terminal can communicate according to the notification signal. May be provided.

According to another embodiment of the present invention, there is provided a method of controlling an access controller for managing a wireless communication network, the method comprising: receiving a signal from the wireless communication terminal or the first access point indicating that the wireless communication terminal is connected to the first access point Receiving; Receiving from the wireless communication terminal or a second access point a signal indicating that the wireless communication terminal is connected to the second access point; And transmitting a notification signal indicating that the wireless communication terminal has accessed the second access point to the first access point, wherein the first access point transmits the notification signal to the first access point, And a validation signal for confirming whether or not the connection is possible.

According to the embodiment of the present invention, the specific access point can determine the validity of a wireless communication terminal that has moved from a specific access point to another access point, and can efficiently manage resources of the access point based on the determination.

In addition, according to the embodiment of the present invention, the validity of the wireless communication terminal can be efficiently determined based on the connection order of the wireless communication terminals connected to the access point or the time when the wireless communication is successfully performed.

In addition, according to the embodiment of the present invention, the validity of the wireless communication terminal can be determined flexibly based on the number of wireless communication terminals connected to the access point.

1 is a diagram illustrating a wireless communication network structure, a wireless communication terminal, an access point, and a connection controller according to an embodiment of the present invention.
2 is a diagram illustrating a method of confirming the validity of a wireless communication terminal according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating a method of confirming the validity of a wireless communication terminal according to another embodiment of the present invention.
4 is a diagram illustrating a method of verifying the validity of a wireless communication terminal according to another embodiment of the present invention.
5 is a diagram illustrating a method of confirming the validity of a wireless communication terminal in a network including a connection controller.
6 is a diagram illustrating a method of controlling an access point, a wireless communication terminal, and a connection controller according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

1 is a diagram illustrating a wireless communication network structure, a wireless communication terminal, an access point, and a connection controller according to an embodiment of the present invention. 1, STA1 to STA6 (100A to 100F) are wireless communication terminals, AP1 200A and AP2 200B are access points, R-AP 200C is a roadside access point, C- (200D) and C-AP2 (200E) represent access points installed in a moving body. For example, the moving object may be a moving object such as a car (passenger car), a train (a train, a subway / a train), a bus, a truck, a platoon, But is not limited thereto. Both arrows indicate wireless communication, and the solid line indicates a wired communication path. The dashed circle in Fig. 1 represents the coverage of the access point, and the dotted circle represents the coverage of the terrestrial access point.

1 (a) shows a wireless communication network structure according to an embodiment of the present invention. According to FIG. 1 (a), an access point can transmit and receive a wireless signal with at least one wireless communication terminal. Meanwhile, the access points C-AP1 (200D) and C-AP2 (200E) installed on the mobile body can provide wireless communication services to the mobile body through networking with the ground access point R-AP 200C. Each of the wireless communication terminals STA1 to STA6 (100A to 100F) can perform wireless communication with a corresponding access point after performing a network connection procedure with a nearby access point. In addition, each of the wireless communication terminals STA1 to STA6 (100A to 100F) may perform wireless communication through the mobile communication network (cellular network) 500 of the LTE. Each access point or mobile communication network may be connected to L2 switch 400A, L3 switch 400B or L4 switch 400C depending on the design scheme of the network. Here, the L2 switch 400A may be a PoE (Power over Ethernet) switch, but is not limited thereto. On the other hand, each switch can be individually connected to the connection controller A 300A, the connection controller B 300B and the connection controller C 300C. Each of the access controllers can perform network / wireless communication resource management, connection management, and the like of the same network layer or subnetwork layer, and can transmit information such as a communication channel that can be utilized in wireless communication to each access point or wireless communication terminal You can assign it. However, the structure of the wireless communication network or the role of the connection controller according to the present invention is not limited to Fig. 1 or the above description.

1 (b) shows a wireless communication terminal 100 according to an embodiment of the present invention. FIG. 1 (c) shows an access point 200 according to an embodiment of the present invention. Lt; RTI ID = 0.0 > 300 < / RTI >

The wireless communication terminal 100, the access point 200, and the access controller 300 according to the embodiment of the present invention may include the transmitting and receiving units 110, 210, and 310, Processor 120 may be included. In addition, according to the method of the present invention, a power supply unit (not shown) for supplying power to the transceiving unit 110 and the processor 120 or a storage unit (not shown) for storing information under the control of the processor 120 (Not shown). According to the method of implementing the present invention, some of the components may be implemented as one component, and some components may be omitted according to the manner of implementing the present invention.

The transceiver units 110, 210, and 310 may transmit and receive wireless signals. The wireless communication terminal 100, the access point 200, and the access controller 300 can perform wireless communication with the external communication device through the transceivers 110, 210, and 310. According to an exemplary embodiment of the present invention, the transmitting and receiving units 110, 210 and 310 can transmit and receive a radio signal using a wireless LAN communication method, but the present invention is not limited thereto. For example, Bluetooth, ZigBee, It is also possible to transmit and receive a radio signal based on a mobile communication network such as a short distance communication method or LTE. Meanwhile, the transmitting and receiving units 210 and 310 of the access point 200 and the access controller 300 can also transmit and receive information through the wired connection.

The processors 120, 220, and 320 may control operations of the respective sections of the wireless communication terminal 100, the access point 200, and the access controller 300. According to a preferred embodiment of the present invention, the processor 120, 220, 320 may be implemented by at least one microprocessor, but is not limited thereto. The processor 120, 220, ) Or a program / application, or a combination of hardware and software.

A detailed description of the manner in which each wireless communication terminal 100, access point 200, and access controller 300 operates will be discussed in conjunction with FIGS. 2-5.

Timer based terminal validity management

FIG. 2 is a diagram illustrating a method of confirming the validity of a wireless communication terminal according to an embodiment of the present invention, and shows an operation method of each wireless communication apparatus according to the flow of time. In FIG. 2, AP1 and AP2 denote a first access point and a second access point, and STA1 and STA2 denote a first wireless communication terminal and a second wireless communication terminal. For convenience of explanation, each of the wireless communication apparatuses in Fig. 2 is referred to as AP1, AP2, STA1, and STA2.

According to a preferred embodiment of the present invention, the access point transmits a validation confirmation signal for confirming whether or not the wireless communication terminal can communicate with the wireless communication terminal, and if the ACK signal for the validation confirmation signal is not received, The terminal can be disconnected from the terminal. Alternatively, according to the preferred embodiment of the present invention, the access point can determine whether or not the execution condition of the validity check for confirming whether or not communication with the wireless communication terminal is possible is satisfied. The access point can perform the validity check on the wireless communication terminal being connected to the access point when the execution condition of the validity check is satisfied. Here, the access point does not have to discriminate whether the 'condition' is satisfied or not. However, if the access point is placed in an operating state (for example, timer expiration) corresponding to the 'condition' It may also operate in a manner that performs inspection. According to a preferred embodiment of the present invention, the validity check is performed by transmitting a signal for confirming the validity of the wireless communication terminal to the wireless communication terminal, and based on whether an ACK signal for the signal for confirming the validity is received, It is possible to determine whether the communication terminal is valid or not. The access point can determine that the wireless communication terminal is not valid when the ACK signal is not received and disconnect the connection with the wireless communication terminal or stop the communication. However, the validity determination method of the wireless communication terminal according to the present invention is not limited to this.

According to a preferred embodiment of the present invention, the validation signal may be a general data packet or an RTS (Ready to Send) or an ARP request (Address Resolution Protocol Request) or a Null Data packet, The ACK signal may be a normal ACK signal, a CTS (Clear to Send) or an ARP reply packet, but is not limited thereto. The validation confirmation signal may be directly generated by the wireless LAN MAC terminal of the access point or an application for access control of the access point may generate a packet having a length of 0 or a short packet and transmit the generated packet to the MAC terminal, . Here, the null data packet may be a packet having only a header and no data, a data type set to QoS Null, and a data-free packet. The Duration field of the RTS packet or the CTS packet may be set to a time value for transmission and reception of an RTS packet and a CTS packet. Thus, the occupied state of wireless communication resources (for example, communication channel, etc.) according to the use of RTS and CTS can be quickly released.

The execution condition of the validity check may be variously provided. Alternatively, the validation acknowledgment signal may be originated by various factors. According to the embodiment of the present invention, when the access point fails to transmit / receive a radio signal to / from the radio communication terminal over a predetermined time, the access point can transmit the validation confirmation signal to the radio communication terminal. For example, when an access point successfully transmits / receives a signal to / from the wireless communication terminal, the access point starts counting of a timer, and when the signal is successfully performed with the wireless communication terminal during the counting, The count can be canceled and the count of the timer can be resumed. Herein, the transmission / reception of signals may include both transmission from the access point to the wireless communication terminal or transmission from the wireless communication terminal to the access point, and whether or not the transmission / reception of the signal is successful may be made by transmitting an ACK signal May be determined depending on whether or not it has been received. Of course, the timer does not start only when the transmission / reception of the signal is successful, and when the access point receives or transmits the signal, the timer may start regardless of the ACK signal.

Referring to FIG. 2, STA1 and STA2 transmit and receive radio signals after completing the network connection procedure with AP1. At this time, when radio signals are transmitted / received between STA1 and AP1, AP1 can start a timer for STA1 (S1100). When a radio signal is transmitted / received between STA1 and AP1 again while the timer for STA1 is being performed, the timer may be canceled and then restarted (S1200) or a new timer may be started. According to the present invention, the access point can individually manage a timer for each wireless communication terminal, but the present invention is not limited to this, and whenever the transmission and reception of a signal is successfully performed regardless of a wireless communication terminal, . Alternatively, according to another embodiment of the present invention, each type of timer may be individually started or restarted based on the type of wireless communication terminal (e.g., smartphone or notebook) connected to the access point.

According to the embodiment of the present invention, the access point can determine that the execution condition of the validity check is satisfied when the count of the timer expires, or can transmit a validity check signal. Here, the count of the timer may be implemented by expiration of the timer when a predetermined time value is subtracted by a unit time (for example, 0.1 second) and becomes 0, but the present invention is not limited thereto. According to a preferred embodiment of the present invention, an access point transmits a signal for confirming the validity of the wireless communication terminal to a wireless communication terminal, and transmits an ACK signal to the wireless communication terminal, It is possible to determine whether the terminal is valid or not. If the ACK signal is received, the access point can determine that the wireless communication terminal is valid and transmit / receive wireless signals continuously. However, if the ACK signal is not received, the access point can determine that the wireless communication terminal is not valid and can disassociate the wireless communication terminal from the wireless communication terminal. Herein, the disconnection may include deletion or collection of an AID (Association ID) referenced when the access point transmits and receives a radio signal with the wireless communication terminal, deletion or deletion of information related to the wireless communication terminal (for example, MAC address of the terminal) And the like. However, the disconnection is not limited to this, and may include the deallocation of wireless communication resources reserved for the wireless communication terminal by the access point.

Referring to FIG. 2, STA1 indicates a situation where a STA1 transmits / receives a radio signal to / from the AP1, and then connects to another access point AP2. The AP1 can determine that the execution condition of the validity check is satisfied when the count of the timer for the STA1 has expired and can perform the validity check on the STA1. Accordingly, AP1 can transmit a signal for validity confirmation to STA1 (S1400). However, since the STA2 has already been connected to the AP2, the STA2 can not receive the signal for the validity check transmitted from the STA1, and therefore can not transmit the ACK signal for the signal to the AP1. The AP 1 which has not received the ACK signal of the STA1 can perform disassociation of the STA1, interruption of the communication or release of the connection to the STA1 (S1500). At this time, according to the embodiment of the present invention, in order to accurately check whether the wireless communication terminal is valid, the transmission of the signal for confirming the validity of the wireless communication terminal and the transmission and reception of the ACK signal therefor are performed a plurality of times . 2, when a signal is transmitted / received between STA2 and AP1, a timer for STA2 may be started (S1600). If the count of the timer expires (S1700), the AP1 can transmit a signal for confirming the validity of the STA2 (S1800). If the STA2 is still connected to the AP1, the STA2 transmits an ACK signal to the AP1 . Thus, AP1 can determine that STA2 is valid.

Meanwhile, according to another embodiment of the present invention, when a timer is started or restarted every time a signal is transmitted / received to / from a wireless communication terminal connected to an access point regardless of the type of the wireless communication terminal, when the count has expired, The validity of each wireless communication terminal can be confirmed according to whether or not ACK of each wireless communication terminal that receives the signal.

Periodic or event-based terminal validation management

FIG. 3 is a diagram illustrating a method of confirming the validity of a wireless communication terminal according to another embodiment of the present invention. 2, the access point and the wireless communication terminal are referred to as AP1, STA1 to STA4, respectively.

According to a preferred embodiment of the present invention, the access point can transmit a validation signal to the wireless communication terminal according to a predetermined period (for example, 100 ms). For example, the access point may start counting a timer, resume counting of the timer after the count of the timer expires, determine that the execution condition of the validity check is satisfied when the count of the timer expires Or transmit a validation signal. The validity check signal and the validity check will be described in detail with reference to FIG. 2, and a description thereof will be omitted. Meanwhile, if the number of wireless communication terminals communicating with the access point exceeds a predetermined maximum number of terminals, the access point can start the progress of the period. For example, the access point can start counting the timer when the number of wireless communication terminals performing communication with the access point exceeds a preset maximum number of terminals. 3 (a) shows a situation in which four wireless communication terminals STA1 to STA4 are connected to AP1. If the maximum number of terminals is 3, the timer of AP1 may be started (S2100). When the count of the timer expires (S2200), a validation process (S2300) for each wireless communication terminal can be performed. At this time, if the STA3 has moved to another access point, since the ACK can not be received from the STA3, the AP1 can release the connection with the STA3 (S2400). On the other hand, the condition for starting the timer described above is not limited to the maximum number of terminals, and the start of the timer can be determined according to various conditions. Further, the maximum number of terminals may be set differently according to the time based on the state of communication resources available to the AP 1, so that the AP 1 can be operated flexibly depending on the situation.

Meanwhile, according to the embodiment of the present invention, the access point can resume counting of the timer after the count of the timer expires. At this time, the resumption of counting of the timer may be performed after the validity check of the wireless communication terminal is completed, or may be performed simultaneously with the validity check.

In addition, although the access point can target all wireless communication terminals connected to the access point during the validity check, the validity check may be performed on a part of the wireless communication terminals connected to the access point. For example, the access point may perform validation for a specific number of wireless communication terminals that have been connected to the access point. Alternatively, the access point may be validated until a certain number of wireless communication terminals are determined to be invalid. Alternatively, the access point may be validated until it disconnects a certain number of wireless communication terminals.

According to a preferred embodiment of the present invention, an access point transmits, to at least a part of the plurality of wireless communication terminals, a plurality of wireless communication terminals including the wireless communication terminal, Signal can be transmitted. Alternatively, the access point may transmit to the plurality of wireless communication terminals including the wireless communication terminal at least a part of the plurality of wireless communication terminals based on the order of the plurality of wireless communication terminals transmitting and receiving the wireless signal to / A validation signal may be transmitted.

To this end, the access point may generate a list or queue of wireless communication terminals in various manners, and may perform validation based on the list or queue. According to a preferred embodiment of the present invention, the access point can generate the terminal list in which the identifiers of the wireless communication terminals are sequentially listed according to the time when the wireless communication terminal completes the network connection procedure with the access point, A signal for confirming the validity of the wireless communication terminal can be transmitted to the wireless communication terminal corresponding to the identifier from the first identifier to the preset order of the list. Referring to FIG. 3 (a), STA1, STA3, STA2, and STA4 are connected to AP1 in the order of network connection procedure, and the terminal list accordingly is shown in FIG. 3 (b). If the predetermined order is 3, the access point can perform validity checking on STA1, STA3, and STA2, and can determine validity based on whether an ACK signal is received from each wireless communication terminal.

According to another embodiment of the present invention, the access point can generate the terminal list based on the time when the access point last performed communication with the wireless communication terminal. At this time, whenever the access point successfully communicates with the wireless communication terminal, the identifier of the wireless communication terminal that has successfully communicated at the end of the terminal list can be located. The access point can transmit a signal for confirming the validity of the wireless communication terminal to the wireless communication terminal corresponding to the identifier from the first identifier to the predetermined order of the terminal list.

FIG. 4 is a diagram illustrating a method of confirming the validity of a wireless communication terminal according to another embodiment of the present invention. Similar to the case of Fig. 3, the access point and the wireless communication terminal are referred to as AP1, STA1 to STA4, respectively.

According to an embodiment of the present invention, when the number of wireless communication terminals connected to the access point is greater than or equal to a predetermined inspection start threshold value, the access point transmits the validation confirmation signal to the wireless communication terminal through the transceiver, The transmission of the validation acknowledgment signal can be stopped if the number of connected wireless communication terminals is less than a predetermined inspection termination threshold value. For example, the access point determines that the execution condition of the validity check is satisfied when the number of the wireless communication terminals registered in the above-mentioned terminal list is equal to or larger than a predetermined inspection start threshold value, It can be determined that the execution condition of the validity check is not satisfied when the number is less than or equal to a predetermined inspection termination threshold value. At this time, the terminal list can be generated according to the method described in FIG. That is, the terminal list may be generated based on the time when the wireless communication terminal completes the network connection procedure with the access point or the time when the transmission / reception unit last performed communication with the wireless communication terminal. However, It does not.

According to Fig. 4 (a), three wireless communication terminals STA1, STA3, and STA2 are connected to AP1 in order at time t1. The leftmost terminal list in Fig. 4 (b) shows the terminal list of AP1 at time t1. Thereafter, at the time t2, the fourth wireless communication terminal STA4 is connected to the AP1, and the terminal list of the AP1 corresponding thereto is the same as the terminal list located at the center of FIG. 4 (b). If the test start threshold value is 4 (S3100), AP1 can perform the validity check on each terminal (S3200). According to FIG. 4 (a), it is determined that STA3 is invalid, (S3300). Since the STA3 no longer performs communication with the AP1, the identifier of the STA3 can be deleted from the terminal list of the AP1, so that the terminal list of the AP1 at the time t3 is identical to the terminal list located on the right side of FIG. . ≪ / RTI > If the inspection completion threshold value is 3, the AP1 can determine that the execution condition of the validity check is not satisfied, and can stop the validity check on the wireless communication terminal accordingly. If another wireless communication terminal is additionally connected to the AP 1 and the identifier of the wireless communication terminal in the terminal list is increased, the validity check according to the inspection start threshold value can be performed again.

Terminal validity management using connection controller

FIG. 5 is a diagram showing a method of confirming the validity of a wireless communication terminal in a network including a connection controller, and shows an operation manner of each wireless communication device according to the passage of time. Similar to the case of Fig. 4, the access point and the wireless communication terminal are referred to as AP1, AP2 and STA1, respectively. FIG. 5 may be a mode of operation in the wireless communication network architecture of FIG. 1 (a), but is not limited thereto.

According to the embodiment of the present invention, when an access point receives an announcement signal indicating that the wireless communication terminal has connected to another access point from an access controller that manages a wireless communication network including the access point, And transmit the validation confirmation signal to the wireless communication terminal through the transceiver. Alternatively, when the access point receives a notification signal indicating that the wireless communication terminal has connected to another access point, the access point can determine that the execution condition of the validity check is satisfied. At this time, after the wireless communication terminal or the access point transmits the connection information to the access controller after the wireless communication terminal is connected to the access point (or the network connection procedure is completed), the wireless communication terminal When the wireless communication terminal or the other access point transmits the connection information to the access controller after the terminal is connected to the other access point (or the network access procedure is completed), the access controller transmits a signal .

According to FIG. 5, after the STA1 connects to the AP1, the STA1 can directly report the network connection to the connection controller (S4100A or S4200). At this time, according to FIG. 1 (a), the STA 1 can transmit a report to the connection controller using an external cellular network or the like as well as wireless LAN communication with the AP 1. In particular, when an application for connection control is installed in the STA1, the application may be operated according to an operation mode according to the relationship between the management program of the connection controller and the client-server program. If a connection control application is not installed in STA1, AP1 can perform reporting as in S4100B. According to an embodiment of the present invention, the report may include, but is not limited to, the MAC address of the STA1, the AID, the SSID of the AP1, and the MAC address. Then, the connection controller can generate the connection status information based on the report (S4200), and the connection status information may include information of the wireless communication terminal connected to the access point. On the other hand, when STA1 moves from AP1 to AP2 and performs network connection, STA1 can directly report the network connection to the connection controller (S4300A or S4300B), as in the previous case. Also in this case, the STA1 can transmit the report to the connection controller via an external cellular network or the like, and if the connection control application is not installed in the STA1, the AP2 can perform the report (S4300B). The connection controller can update connection state information based on the second report (S4400), and can determine that the access point of the STA1 has been changed in the updating process. Based on the determination result, the access controller can instruct the AP1 to release the STA1 related information or transmit a notification signal notifying the change of the access point of the STA1 (S4500). Alternatively, the access controller may induce validation of the wireless communication terminal of AP1 through the notification signal. According to another embodiment of the present invention, the access controller may transmit the notification signal to the previous access point when the SSID or the MAC address of the access point related to the MAC address of the STA1 is changed. Alternatively, the access controller may simply transmit the notification signal to the previous access point if the AID of STA1 has changed. The AP1 can transmit the validity confirmation signal to the STA1 based on the announcement signal (S4600). Since the STA1 can not receive the validity confirmation signal, the AP1 can not transmit the ACK signal to the AP1. As a result, (S4700).

Various validation execution conditions have been introduced through Figures 2-5. According to a preferred embodiment of the present invention, at least two of the execution conditions of the validity check described above can be applied redundantly. For example, the validity check can be performed only when the number of wireless communication terminals connected to the access point is equal to or greater than the inspection start threshold value and the progress of the timer due to transmission and reception of the wireless signal has expired. As another example, the access point may initiate a timer when the notification signal is received from the access controller, and may perform a validity check on each wireless communication terminal when the timer expires. The timer may be restarted when the progress has expired, and may be validated each time the timer expires. Thereafter, when the number of wireless communication terminals connected to the access point is equal to or less than the inspection completion threshold value, it is determined that the execution condition of the validity check is not satisfied and the validity check may be stopped. However, the embodiment of the validity check based on the redundant execution condition is not limited to this.

1 to 5, a wireless communication terminal according to an exemplary embodiment of the present invention receives a signal for confirming the validity of the wireless communication terminal from an access point, and transmits an ACK signal to the signal for confirming the validity To the access point. In this case, the signal for confirming the validity may be a signal for confirming whether or not the access point can communicate with the wireless communication terminal, and if the execution condition of the validity check is satisfied, A validation signal can be transmitted. The execution conditions of the validity check are the same as those described with reference to FIG. 2 to FIG.

1 and 5, a connection controller according to an embodiment of the present invention receives a signal indicating that the wireless communication terminal is connected to the first access point from a wireless communication terminal or a first access point, When the wireless communication terminal or the second access point receives a signal indicating that the wireless communication terminal is connected to the second access point, the wireless communication terminal informs the first access point that the wireless communication terminal has connected to the second access point Can be transmitted. Alternatively, the access controller may transmit to the first access point a notification signal indicating that the wireless communication terminal has connected to the second access point, to determine whether the first access point is capable of communicating with the wireless communication terminal It can be induced to execute the inspection.

On the other hand, according to FIG. 1, the access point can be mounted on a moving object such as an automobile or a train, and can transmit and receive a wireless signal to / from a wireless communication terminal in or around the moving object. According to another embodiment of the present invention, the access point can transmit a validation signal based on the moving speed of the moving object. For example, the access point may transmit the validation signal when the speed of the mobile is less than 30 km / h. Referring to FIG. 2, the access point can transmit a validation signal when it can not transmit / receive a radio signal to / from a wireless communication terminal for a predetermined time or longer. Here, the predetermined time may be determined based on the speed of the moving object. For example, the preset time may be 10 ms when the speed of the moving body is less than 10 km / h, and the predetermined time is 20 ms when the speed of the moving body is 10 km / h or more. Accordingly, when the speed of the moving object is relatively fast, the validation confirmation signal can be transmitted to the corresponding radio communication device within a relatively short period of time after the transmission and reception of the radio signal. Also, with reference to FIG. 3, the access point may transmit a validation signal according to a predetermined period, which period may be determined based on the speed of the moving object. For example, the access point may have a period of 200 ms when the speed of the moving object is less than 10 km / h, and a period of 100 ms when the speed is 10 km / h or more. That is, as the mobile moves faster, the access point can transmit the validation signal more frequently. According to the above description, the start of the period may be started when the number of the wireless communication terminals performing communication with the access point exceeds the preset maximum number of terminals. Here, the maximum number of terminals may be determined based on the speed of the moving object. That is, the maximum number of terminals may be 10 when the speed of the moving body is less than 10 km / h and the maximum number of terminals may be 4 when the speed of the moving body is more than 10 km / h. Accordingly, when the speed of the moving object increases, the access point can start the progress of the period even when performing communication with a relatively small number of wireless communication terminals. In addition, according to FIG. 4, whether or not the validation signal of the access point is transmitted can be determined by the inspection start threshold value or the inspection end threshold value. The inspection start threshold value or the inspection end threshold value, Can be determined. For example, when the speed of the moving object is less than 10 km / h, the inspection start threshold value may be 10, the inspection end threshold value may be 6, and when the speed of the moving object is 10 km / h or more, 5, and the inspection end threshold value may be 2. That is, since the position of the access point mounted on the mobile terminal changes according to the movement of the mobile terminal, the examination start threshold value is lowered as the mobile terminal moves at a higher speed, and the condition for starting the validity check on each wireless terminal is relaxed And the validation can be maintained until a relatively small number of access points are connected. However, the conditions such as the speed of the moving body described above are merely exemplary, and the present invention is not limited thereto.

6 is a diagram illustrating a method of controlling an access point, a wireless communication terminal, and a connection controller according to an embodiment of the present invention.

6A, a method of controlling an access point according to an exemplary embodiment of the present invention includes a step (S110) of transmitting a validation confirmation signal for confirming whether or not the wireless communication terminal can communicate with a wireless communication terminal, And disassociating the connection with the wireless communication terminal if the ACK signal for the signal for confirming the wireless communication terminal is not received (S120).

Here, in the step of transmitting the validation signal (S110), if the access point fails to transmit / receive a radio signal to / from the radio communication terminal for a predetermined period of time, it may transmit the validation confirmation signal to the radio communication terminal.

Here, in the step of transmitting the validation signal (S110), the access point may transmit the validation confirmation signal to the wireless communication terminal according to a predetermined period. At this time, when the number of wireless communication terminals that perform communication with the access point exceeds a predetermined maximum number of terminals, the progress of the period may start.

Here, in the step of transmitting the validation signal (S110), the access point transmits at least one of the plurality of wireless communication terminals to the access point based on the order in which a plurality of wireless communication terminals including the wireless communication terminal are connected The validation signal can be transmitted as a part thereof.

Here, in the step of transmitting the validation signal (S110), the access point transmits, to the plurality of radio communication terminals including the radio communication terminal, a plurality of radio communication terminals based on the order of the plurality of radio communication terminals, And transmit the validation confirmation signal to at least a part of the plurality of wireless communication terminals.

The access point transmits the validation confirmation signal to the wireless communication terminal when the number of the wireless communication terminals connected to the access point is equal to or greater than a predetermined inspection start threshold value in the step of transmitting the validation signal (S110) The transmission of the validation acknowledgment signal can be stopped if the number of the wireless communication terminals connected to the wireless communication terminal is less than a predetermined inspection termination threshold value.

Here, in the step of transmitting the validation signal (S110), the access point receives from the access controller that manages the wireless communication network including the access point, a notification signal indicating that the wireless communication terminal has connected to another access point The wireless communication terminal can transmit the validation confirmation signal to the wireless communication terminal. At this time, after the wireless communication terminal or the access point transmits the connection fact to the access controller after the wireless communication terminal is connected to the access point, the wireless communication terminal transmits the notification signal to the other access point And may be a signal transmitted from the access controller to the access point when the wireless communication terminal or the other access point transmits the connection information to the access controller after the connection. The detailed description of steps S110 and S120 is duplicated and will be omitted.

A control method of an access point according to another embodiment of the present invention may include determining whether an execution condition of a validity check for confirming whether or not the access point is capable of communicating with a wireless communication terminal is satisfied. Here, the execution condition of the validity check may be variously provided. According to an embodiment of the present invention, when an access point successfully transmits / receives a signal to / from a wireless communication terminal, it starts counting a timer, and when the access point and the wireless communication terminal successfully The count of the timer is canceled and the count of the timer is resumed. If the count of the timer expires, it can be determined that the execution condition of the validity check is satisfied. Alternatively, it can be determined that the execution condition of the validity check is satisfied when the progress of the timer periodically starting and resuming the access point has expired. At this time, when the number of wireless communication terminals performing communication with the access point exceeds the predetermined maximum number of terminals, counting of the timer can be started. Alternatively, the access point may generate the terminal list based on the time when the wireless communication terminal completes the network connection procedure with the access point or the time when the transmission / reception part last performed communication with the wireless communication terminal. When the number of the wireless communication terminals registered in the terminal list is equal to or greater than a predetermined inspection start threshold value, and when the number of wireless communication terminals registered in the terminal list is equal to or less than a predetermined inspection end threshold value, It may be determined that the execution condition of the inspection is not satisfied. Alternatively, when the access point receives a notification signal indicating that the wireless communication terminal has connected to another access point from the connection controller, it can be determined that the execution condition of the validity check is satisfied. Here, the notification signal may be a notification that the wireless communication terminal or the access point reports network connection to the access controller after the wireless communication terminal completes the network connection procedure with the access point, The access controller may be a signal transmitted to the access point when the wireless communication terminal or the other access point reports to the access controller that the access point has connected to the network after completing the network access procedure with another access point.

And transmit a signal for confirming the validity of the wireless communication terminal to the wireless communication terminal when the execution condition is satisfied. Here, the access point can generate a terminal list in which the identifiers of the wireless communication terminals are sequentially listed according to a time point at which the wireless communication terminal completes the network connection procedure with the access point. A signal for confirming the validity of the radio communication terminal can be transmitted to the radio communication terminal corresponding to the identifier up to the radio communication terminal. Alternatively, the access point can generate a terminal list based on a time point when the access point last performed communication with the wireless communication terminal. When the access point successfully communicates with the wireless communication terminal, And transmits a signal for confirming the validity of the wireless communication terminal to the wireless communication terminal corresponding to the identifier from the first identifier to the predetermined order.

Determining that the wireless communication terminal is not valid if the ACK signal for the validation signal is not received, and releasing the connection with the wireless communication terminal. Here, the interruption of the communication may include a process of deleting or recalling the AID that the access point refers to when transmitting / receiving a radio signal with the wireless communication terminal, and deleting the MAC address of the wireless communication terminal.

FIG. 6B shows a control method of a wireless communication terminal, which includes receiving (S210) a signal for confirming the validity of the wireless communication terminal from an access point, and transmitting an ACK signal for confirming the validity to the access (S220). ≪ / RTI > At this time, the signal for confirming the validity may be a signal for confirming whether or not the access point can communicate with the wireless communication terminal.

6C shows a method of controlling an access controller for managing a wireless communication network. The method includes receiving a network connection procedure completion report of the wireless communication terminal and the first access point from a wireless communication terminal or a first access point (S310), receiving from the wireless communication terminal or the second access point a network connection procedure completion report of the wireless communication terminal and the second access point (S320), the wireless communication terminal (Not shown) that the wireless communication terminal has moved to the second access point, and transmits a notification signal indicating that the wireless communication terminal has accessed the second access point to the first access point, A step of instructing execution of a validity check for confirming whether or not communication with the wireless communication terminal is possible (S330). Since each step of FIG. 6 (c) has been described in detail with reference to FIG. 5, a description thereof will be omitted.

According to the embodiment of the present invention, the specific access point can determine the validity of a wireless communication terminal that has moved from a specific access point to another access point, and can efficiently manage resources of the access point based on the determination.

In addition, according to the embodiment of the present invention, the validity of the wireless communication terminal can be efficiently determined based on the connection order of the wireless communication terminals connected to the access point or the time when the wireless communication is successfully performed.

In addition, according to the embodiment of the present invention, the validity of the wireless communication terminal can be determined flexibly based on the number of wireless communication terminals connected to the access point.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Accordingly, it is to be understood that within the scope of the appended claims, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims (14)

In an access point for performing communication with a wireless communication terminal,
A transmitting and receiving unit for transmitting and receiving a radio signal; And
And a processor for controlling the operation of the transceiver,
The processor comprising:
The wireless communication terminal transmits a validation confirmation signal for confirming whether or not the wireless communication terminal can communicate with the wireless communication terminal through the transceiver, and releases the connection with the wireless communication terminal if the ACK signal for the validation confirmation signal is not received Disassociation)
Wherein the disconnection includes an AID (Association ID) assigned to the wireless communication terminal and deletion of information related to the wireless communication terminal.
The method according to claim 1,
The processor comprising:
Wherein the wireless communication terminal transmits the validation confirmation signal to the wireless communication terminal through the transmission / reception unit when the wireless communication terminal can not transmit / receive a wireless signal to / from the wireless communication terminal for a predetermined period of time or longer through the transmission / reception unit.
The method according to claim 1,
The processor comprising:
And transmits the validation confirmation signal to the wireless communication terminal through the transceiver unit according to a predetermined period.
The method of claim 3,
The processor comprising:
And transmits the validation confirmation signal to the wireless communication terminal according to the predetermined period when the number of wireless communication terminals performing communication with the access point exceeds a preset maximum number of terminals.
The method of claim 3,
The processor, via the transceiver,
Wherein the access point transmits the validation confirmation signal to at least a part of the plurality of wireless communication terminals based on a sequence in which a plurality of wireless communication terminals including the wireless communication terminal are connected to the access point.
The method of claim 3,
For a plurality of wireless communication terminals including the wireless communication terminal,
The processor, via the transceiver,
And transmits the validity confirmation signal to at least a part of the plurality of wireless communication terminals based on the order of the plurality of wireless communication terminals transmitting and receiving the wireless signal to / from the transmission / reception unit.
The method according to claim 1,
The processor comprising:
When the number of the wireless communication terminals connected to the access point is greater than or equal to a preset inspection start threshold, transmits the validation confirmation signal to the wireless communication terminal through the transceiver,
And stops transmitting the validation acknowledgment signal if the number of wireless communication terminals connected to the access point is less than a predetermined inspection termination threshold value.
The method according to claim 1,
The processor comprising:
When receiving a notification signal indicating that the wireless communication terminal has connected to another access point from an access controller that manages a wireless communication network including the access point through the transceiving unit, Signal to the wireless communication terminal.
9. The method of claim 8,
The notification signal includes:
After the wireless communication terminal is connected to the access point, after the wireless communication terminal or the access point transmits the connection fact to the connection controller,
Wherein the access controller is a signal transmitted to the access point when the wireless communication terminal or the other access point transmits the connection information to the access controller after the wireless communication terminal is connected to the other access point Access point.
The method according to claim 1,
Wherein the ACK signal for the validation confirmation signal is a Clear to Send (CTS) packet when the validation confirmation signal is a Ready to Send (RTS) packet,
The ACK signal for the validation acknowledgment signal is an ARP reply packet when the validation acknowledgment signal is an ARP request packet (Address Resolution Protocol Request)
Wherein when the validity check signal is a null data packet, the ACK signal for the validity check signal is an ACK signal for the data packet,
Wherein the RTS packet and the Duration field of the CTS packet are set as time values for transmission and reception of the RTS packet and the CTS packet.
A method for controlling an access point,
Transmitting, to the wireless communication terminal, a validation confirmation signal for confirming whether the wireless communication terminal is capable of communicating; And
And disassociating the wireless communication terminal from the wireless communication terminal if an ACK signal for the validation signal is not received,
Wherein the disconnection includes a number of AIDs assigned to the wireless communication terminal and deletion of information related to the wireless communication terminal.
In a wireless communication terminal performing communication with an access point,
A transmitting and receiving unit for transmitting and receiving a radio signal; And
And a processor for controlling the operation of the transceiver,
The processor comprising:
Receiving a signal for confirming the validity of the wireless communication terminal from the access point through the transceiving unit, and transmitting an ACK signal to the access point to confirm the validity,
Wherein the signal for confirming the validity includes:
Wherein the wireless communication terminal is a signal for confirming whether or not the access point can communicate with the wireless communication terminal.
In a connection controller for management of a wireless communication network,
A transmitting and receiving unit for transmitting and receiving a wireless signal or a wired signal; And
And a processor for controlling the operation of the transceiver,
The processor comprising:
After receiving a signal from the wireless communication terminal or the first access point through the transceiver to indicate that the wireless communication terminal is connected to the first access point,
When the wireless communication terminal or the second access point receives a signal indicating that the wireless communication terminal is connected to the second access point through the transceiver,
And transmits a notification signal indicating that the wireless communication terminal has accessed the second access point to the first access point through the transceiver,
Wherein the first access point transmits a validation signal for confirming whether or not the wireless communication terminal is capable of communicating in accordance with the notification signal.
A control method of an access controller for managing a wireless communication network,
Receiving a signal from the wireless communication terminal or the first access point indicating that the wireless communication terminal is connected to the first access point;
Receiving from the wireless communication terminal or a second access point a signal indicating that the wireless communication terminal is connected to the second access point; And
And transmitting a notification signal indicating that the wireless communication terminal has connected to the second access point to the first access point,
Wherein the first access point transmits a validation signal for confirming whether the wireless communication terminal is capable of communicating in accordance with the notification signal.

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