WO2019177231A1

WO2019177231A1 - Method for transferring information on target access point in wireless lan system and access point using same

Info

Publication number: WO2019177231A1
Application number: PCT/KR2018/015163
Authority: WO
Inventors: 박기원; 윤정환; 조영준
Original assignee: 엘지전자 주식회사
Priority date: 2018-03-16
Filing date: 2018-12-03
Publication date: 2019-09-19

Abstract

A method for transferring information on a target access point in a wireless LAN system, according to one embodiment of the present invention, comprises: a step in which when a wireless device coupled to a first AP in a first coverage of the first AP moves towards a second coverage of a second AP, the first AP decides to hand over the wireless device to the second AP; a step in which the first AP receives a DPP setting request frame from the wireless device; and a step in which the first AP transmits a DPP setting response frame to the wireless device in response to the DPP setting request frame, wherein the DPP setting response frame comprises a target BSSID for the second AP.

Description

Method for delivering information about target access point in WLAN system and access point using same

The present disclosure relates to wireless communication, and more particularly, to a method for delivering information on a target access point in a WLAN system and an access point using the same.

Direct communication technology that allows devices to easily connect with each other without a wireless access point (AP), which is basically required in a WLAN system, and is a Wi-Fi Direct or a Wi-Fi peer-topeer. ) Is being discussed.

According to Wi-Fi Direct, devices can be connected without going through a complicated configuration process, and in order to provide various services to a user, they can support an operation of exchanging data with each other at a communication speed of a general WLAN system.

The WFA (Wi-Fi Alliance) introduces a platform that supports a variety of services (e.g. Send, Play, Display, Print, etc.) using the Wi-Fi Direct link. Technology is under discussion. This may be referred to as Wi-Fi Direct Service (WFDS).

An object of the present specification is to provide a method for delivering information about a target access point in a WLAN system having improved performance and an access point using the same.

In a WLAN system according to an embodiment of the present invention, a method for delivering information about a target access point includes moving a wireless device associated with a first AP toward a second coverage area of a second AP within a first coverage area of a first AP. When, the first AP determines to hand over the wireless device to the second AP; Receiving, by the first AP, a DPP setup request frame from the wireless device; And sending, by the first AP, the DPP setup response frame to the wireless device in response to the DPP setup request frame, wherein the DPP setup response frame includes a target BSSID for the second AP.

According to one embodiment of the present specification, a method for delivering information about a target access point in a WLAN system having improved performance and an access point using the same are provided.

1 is a conceptual diagram illustrating a structure of a WLAN system.

2 is a conceptual diagram illustrating a scanning method in a WLAN.

3 is a conceptual diagram illustrating an authentication and association procedure after scanning of an AP and an STA.

4 is a diagram illustrating a neighbor discovery process.

5 is a conceptual diagram of a DPP procedure.

6 is a flowchart illustrating a process of performing a DPP procedure between wireless devices.

FIG. 7 is a conceptual diagram illustrating a handover operation of a wireless device in a WLAN system including multiple APs.

8 is a diagram illustrating a handover procedure of a wireless device supporting a BTM function.

9 is a diagram illustrating a handover procedure of a wireless device that does not support the BTM function.

10 is a flowchart illustrating a method for delivering information about a target AP in a WLAN system according to an embodiment of the present invention.

11 is a flowchart illustrating a method for delivering information about a target AP in a WLAN system according to another embodiment.

12 is a flowchart illustrating a method for delivering information on a target AP in a WLAN system according to another embodiment.

13 is a block diagram illustrating a wireless device to which the present embodiment can be applied.

14 is a block diagram illustrating an example of an apparatus included in a processor.

The above-described features and the following detailed description are all exemplary for ease of description and understanding of the present specification. That is, the present specification is not limited to this embodiment and may be embodied in other forms. The following embodiments are merely examples to fully disclose the present specification, and are descriptions to convey the present specification to those skilled in the art. Thus, where there are several methods for implementing the components of the present disclosure, it is necessary to clarify that any of these methods may be implemented in any of the specific or equivalent thereof.

In the present specification, when there is a statement that a configuration includes specific elements, or when a process includes specific steps, it means that other elements or other steps may be further included. That is, the terms used in the present specification are only for describing specific embodiments and are not intended to limit the concept of the present specification. Furthermore, the described examples to aid the understanding of the invention also include their complementary embodiments.

The terminology used herein has the meaning commonly understood by one of ordinary skill in the art to which this specification belongs. Terms commonly used should be interpreted in a consistent sense in the context of the present specification. In addition, terms used in the present specification should not be interpreted in an idealistic or formal sense unless the meaning is clearly defined. Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

1 is a conceptual diagram illustrating a structure of a WLAN system. FIG. 1A shows the structure of an infrastructure network of the Institute of Electrical and Electronic Engineers (IEEE) 802.11.

Referring to FIG. 1A, the WLAN system 10 of FIG. 1A may include at least one basic service set (hereinafter, referred to as 'BSS', 100, 105). The BSS is a set of access points (APs) and stations (STAs) that can successfully synchronize and communicate with each other, and is not a concept indicating a specific area.

For example, the first BSS 100 may include a first AP 110 and one first STA 100-1. The second BSS 105 may include a second AP 130 and one or more STAs 105-1, 105-2.

The infrastructure BSS (100, 105) may include at least one STA, AP (110, 130) providing a distribution service (Distribution Service) and a distribution system (DS, 120) connecting a plurality of APs. have.

The distributed system 120 may connect the plurality of

BSSs

100 and 105 to implement an extended service set 140 which is an extended service set. The ESS 140 may be used as a term indicating one network to which at least one

AP

110 or 130 is connected through the distributed system 120. At least one AP included in one ESS 140 may have the same service set identification (hereinafter, referred to as SSID).

The portal 150 may serve as a bridge for connecting the WLAN network (IEEE 802.11) with another network (for example, 802.X).

In a WLAN having a structure as shown in FIG. 1A, a network between

APs

110 and 130 and a network between

APs

110 and 130 and STAs 100-1, 105-1, and 105-2 may be implemented. Can be.

1B is a conceptual diagram illustrating an independent BSS. Referring to FIG. 1B, the WLAN system 15 of FIG. 1B performs communication by setting a network between STAs without the

APs

110 and 130, unlike FIG. 1A. It may be possible to. A network that performs communication by establishing a network even between STAs without the

APs

110 and 130 is defined as an ad-hoc network or an independent basic service set (BSS).

Referring to FIG. 1B, the IBSS 15 is a BSS operating in an ad-hoc mode. Since IBSS does not contain an AP, there is no centralized management entity. Thus, in the IBSS 15, the STAs 150-1, 150-2, 150-3, 155-4, and 155-5 are managed in a distributed manner.

All STAs 150-1, 150-2, 150-3, 155-4, and 155-5 of the IBSS may be mobile STAs, and access to a distributed system is not allowed. All STAs of the IBSS form a self-contained network.

The STA referred to herein includes a medium access control (MAC) conforming to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard and a physical layer interface to a wireless medium. As any functional medium, it can broadly be used to mean both an AP and a non-AP Non-AP Station (STA).

The STA referred to herein includes a mobile terminal, a wireless device, a wireless transmit / receive unit (WTRU), a user equipment (UE), and a mobile station (MS). It may also be called various names such as a mobile subscriber unit or simply a user.

2 is a conceptual diagram illustrating a scanning method in a WLAN.

Referring to FIG. 2, a scanning method may be classified into passive scanning 200 and active scanning 250.

Referring to FIG. 2A, the passive scanning 200 may be performed based on the beacon frame 230 that the AP 210 broadcasts periodically. The AP 210 of the WLAN may broadcast the beacon frame 230 to the non-AP STA 240 every specific period (for example, 100 msec).

The beacon frame 230 may include information about the current network. The non-AP STA 240 may periodically receive the beacon frame 230. In order to perform an authentication / association process, the non-AP STA 240 may perform scanning on the AP 210 and the channel based on the network information included in the beacon frame 230.

The passive scanning method 200 is a technique in which the non-AP STA 240 receives the beacon frame 230 transmitted from the AP 210 without first transmitting the frame. Thus, passive scanning 200 has the advantage that the overall overhead incurred by data transmission / reception in the network is small.

However, since scanning can be performed manually in proportion to the period of the beacon frame 230, the time taken to perform scanning increases.

For a detailed description of the beacon frame, see 8.3. IEEE Draft P802.11-REVmb ™ July 2015, IEEE Standard for Information Technology Telecommunications and information exchange between systems--and metropolitan area networks--hereinafter IEEE 802.11). It is described in Section 3.2.

Referring to FIG. 2B, the active scanning 250 is a technique in which the non-AP STA 290 transmits the probe request frame 270 to the AP 260 to proactively perform scanning.

The AP 260 may receive the probe request frame 270 from the non-AP STA 290. The AP 260 may wait for a random time to prevent frame collision. The AP 260 may transmit a probe response frame 280 including network information to the non-AP STA 290 in response to the probe request frame 270. The non-AP STA 290 may obtain network information based on the received probe response frame 280.

In the case of the active scanning 250, since the non-AP STA 290 performs the scanning, the time used for scanning is short. However, since the probe request frame 270 needs to be transmitted by the non-AP STA 290, network overhead for frame transmission and reception increases.

Probe request frame 270 is disclosed in IEEE 802.11 8.3.3.9 and probe response frame 280 is disclosed in IEEE 802.11 8.3.3.10.

When the above scanning procedure is completed, the AP and the STA may perform an authentication and association procedure.

2 and 3, the non-AP STA may perform an authentication and association procedure with one of a plurality of APs that have completed the scanning procedure through passive / active scanning. For example, authentication and association procedures may be performed through two-way handshaking.

FIG. 3A is a conceptual diagram illustrating an authentication and combining procedure after passive scanning, and FIG. 3B is a conceptual diagram illustrating an authentication and combining procedure after active scanning.

The authentication and association procedure can be performed regardless of whether an active scanning method or passive scanning was used. For example, the

APs

300 and 350 may connect to the

non-AP STAs

305 and 355, an authentication request frame 310, an authentication response frame 320, and an association request frame. , 330, and association response frame 340, the authentication and association procedure may be performed.

In detail, the authentication procedure may be performed by transmitting the authentication request frame 310 to the

APs

300 and 350 in the

non-AP STAs

305 and 355. The

AP

300 or 350 may transmit the authentication response frame 320 to the

non-AP STAs

305 and 355 in response to the authentication request frame 310. Authentication frame format is described in IEEE 802.11 8.3.3.11.

In detail, the joining procedure may be performed by transmitting the join request frame 330 to the

APs

300 and 305 in the

non-AP STAs

305 and 355. The

AP

300 or 350 may transmit the association response frame 340 to the

non-AP STAs

305 and 355 in response to the association request frame 330.

The association request frame 330 may include information regarding the capability of the

non-AP STAs

305 and 355. The

APs

300 and 350 may determine whether to support the

non-AP STAs

305 and 355 based on the information about the performance of the

non-AP STAs

305 and 355 included in the association request frame 330. Can be.

For example, when the support for the

non-AP STAs

305 and 355 is possible, the

APs

300 and 350 support the association request frame 340 in the association response frame 340, and why, and support the association request frame 340. Capability information may be included and transmitted to the

non-AP STAs

305 and 355. Association frame format is described in IEEE 802.11 8.3.3.5/8.3.3.6.

If the combined procedure mentioned in FIG. 3 is performed, a normal data transmission and reception procedure may be performed between the AP and the STA.

4 is a diagram illustrating a neighbor discovery process. 4 may be understood as an operation between a peer to peer (P2P) device and a P2P device.

Referring to FIG. 4, in S410, a neighbor discovery process may be initiated by an indication of a station management entity (SME) / application / user / vendor. For example, the neighbor discovery process may include a scan phase S412 and a find phase S414-S416.

The scan step S412 may include an operation of scanning for all available wireless channels according to the 802.11 scheme. This allows the P2P device to identify the best operating channel.

The search steps S414-S416 may include a listen mode S414 and a search mode S416. The P2P device may alternately repeat the listening mode S414 and the search mode S416. The

P2P devices

202 and 204 may perform active scanning using a probe request frame in the search mode S416.

For example, the search range may be limited to a social channel such as channel 1, channel 6, or channel 11 (eg, 2412 MHz, 2437 MHz, 2462 MHz) for quick searching.

In addition, the

P2P devices

202 and 204 may maintain a reception state on a selected one of three social channels in the listening mode S414.

In this case, when a probe request frame transmitted by another P2P device (eg, 202) in the search mode is received, the P2P device (eg, 204) may respond with a probe response frame.

The time (eg, 100, 200, 300 Time Units (TU)) for the listening mode S414 may be randomly determined. P2P devices can reach each other's common channels through repetition of the search mode and the receive mode.

If another P2P device is found, the P2P device may exchange probe request frames and probe response frames with other P2P devices. This allows P2P devices to discover / exchange each other's device type, manufacturer or friendly device name.

If necessary information about the neighboring P2P device found through the neighbor discovery process is obtained, the P2P device (eg, 202) may inform the SME / application / user / vendor of the P2P device discovery (S418).

At present, P2P is mainly used for semi-static communication such as remote printing, photo sharing and the like. However, due to the popularity of Wi-Fi devices and location-based services, the utilization of P2P is getting wider.

For example, social chat (e.g., wireless devices subscribed to Social Network Service (SNS) recognize wireless devices in the vicinity and send and receive information based on location based services), location-based advertising, location- P2P is expected to be actively used for news broadcasting and game linkage between wireless devices. For convenience, such P2P applications are referred to as novel P2P applications.

5 is a conceptual diagram of a device provisioning protocol (DPP) procedure.

Referring to FIG. 5, the DPP architecture for the DPP procedure may include a DPP Bootstrapping protocol, a DPP Authentication protocol, a DPP Configuration protocol, and a DPP Introduction protocol. You can define the device roles.

In the BPP procedure, there can be two types of roles for the wireless device. For example, there may be a role of a configurator and an enrollee. As another example, there may be a role of an initiator and a responder.

For clarity and concise description of FIG. 5, the configurator may be understood as the first wireless device 510. In addition, the registrant may be understood as the second wireless device 520.

The first wireless device 510 as a configurator may support setup of the second wireless device 520 as a registrant. Constructors and registrants may engage in the DPP bootstrap protocol, the DPP authentication protocol, and the DPP configuration protocol.

The configurator or registrar may play the role of an initiator in the DPP bootstrap protocol and the DPP authentication protocol. However, only an enrollee can initiate the DPP configuration protocol and the DPP introduction protocol.

The DPP authentication protocol may require the initiator to obtain the responder's bootstrapping key as part of the bootstrap mechanism. Optionally, to provide mutual authentication, the wireless devices can obtain each other's bootstrap keys.

Once the DPP authentication protocol is complete, the configurator can provision the registrant for device-to-device communication or infrastructure communication.

As part of this provisioning, the configurator may allow the enrollee to establish secure associations with other peers in the network. Here, the peer may be understood as the wireless device 530 already configured by the constructor.

The constructor and the registrant can be associated with the DPP authentication protocol. Depending on the bootstrap scenario, the configurator or registrar may play the role of initiator or responder, respectively.

The wireless device initiating the DPP authentication protocol may serve as the initiator. The wireless device responding to the initiator's request may act as a responder. The DPP authentication protocol may provide the initiator with authentication of the responder. Optionally, the DPP authentication protocol may provide the responder with authentication of the initiator.

For example, to perform unidirectional authentication, the initiator can obtain the responder's bootstrapping key. In addition, to selectively perform mutual authentication, the initiator and the responder may obtain each other's bootstrap keys.

For example, to configure an unprovisioned device 520 that serves as a registrar, the wireless device 510 may serve as a configurator. For example, an unprovisioned wireless device can be an access point or other wireless device.

When the wireless device 510 serving as a configurator initiates the DPP authentication protocol with the unprovisioned wireless device 520, the wireless device 510 may serve as an initiator.

6 is a flowchart illustrating a process of performing a DPP procedure between wireless devices. The DPP procedure of FIG. 6 may be implemented in a 3-way handshaking manner.

5 and 6, the first wireless device 610 may serve as an initiator, and the second wireless device 620 may serve as a responder. In addition, the first wireless device 610 may serve as a configurator, and the second wireless device 620 may serve as an enrollee.

In operation S610, the first wireless device 610 and the second wireless device 620 may perform a DPP bootstrap protocol.

For example, the first wireless device 610 serving as a configurator may obtain bootstrap information from the second wireless device 620 serving as a registrant using an out-of-band mechanism.

For example, the OOB mechanism may be implemented based on a scan QR code method based on a QR code (eg, 521), an NFC tap method, or a Bluetooth Low Energy exchange method. .

For example, the bootstrap information may include information regarding the enrollee's bootstrapping public key for the DPP authentication protocol. As an example, the bootstrap public key may be used only for the DPP authentication protocol by the constructor and registrant.

For example, the information on the global operating class channel or the channel list may be further included in the bootstrap information.

In this case, to initiate the DPP authentication protocol, the wireless device (eg, 620) may indicate that it is listening on one of the listed channels for another device (eg, 610).

As another example, the information on the global operating class channel or the information on the channel list may not be included in the bootstrap information.

In this case, the wireless device (eg, 620) may not provide guidance to which device is listening to the other device (eg, 610). Accordingly, another device (eg, 610) must iterate over all available channels.

Iteration over multiple channels can result in significant additional delay in the DPP authentication protocol. Accordingly, an apparatus using QR Code bootstrapping may be required to include a single channel or at most a short list of possible channels in the bootstrap information.

The first wireless device 610 of FIG. 6 may start an operation on a specified channel based on the bootstrap information obtained from the second wireless device 620. The second wireless device 620 of FIG. 6 may listen on a specific channel during step S610.

In operation S620, the first wireless device 610 and the second wireless device 620 may perform a DPP authentication protocol.

For example, the first wireless device 610 serving as a configurator may transmit a DPP authentication request frame to the second wireless device 620 serving as a registrar. In this case, the DPP authentication request frame may be transmitted through at least one channel corresponding to bootstrap information (eg, a channel list).

In operation S621, the first wireless device 610 may transmit a DPP authentication request frame to the second wireless device 620. Subsequently, the first wireless device 610 may wait for a response to the DPP authentication request frame transmitted in step S621.

For example, the first wireless device 610 may determine whether a DPP authentication response frame, which is a response to the DPP authentication request frame transmitted in step S621, from the second wireless device 620 is received within a predetermined time. .

For example, the predetermined time may be set based on a transmission time of the DPP authentication request frame in step S621.

For clarity and concise description of FIG. 6, it may be assumed that the DPP authentication response frame is not received until a predetermined time elapses in response to the DPP authentication request frame transmitted in step S621.

If the DPP authentication response frame is not received until a predetermined time elapses according to the above assumption, step S622 is performed for retransmission of the DPP authentication response frame.

In operation S622, the first wireless device 610 may retransmit the DPP authentication request frame to the second wireless device 620. Subsequently, the first wireless device 610 may wait for a response to the DPP authentication request frame transmitted in step S622.

For example, the first wireless device 610 may determine whether a DPP authentication response frame, which is a response to the DPP authentication request frame retransmitted in step S622, from the second wireless device 620 within a predetermined time. .

For example, the predetermined time may be set based on a transmission time of the DPP authentication request frame in step S622.

For clarity and concise description of FIG. 6, it may be assumed that the DPP authentication response frame is not received until a predetermined time elapses in response to the DPP authentication request frame resent in step S622.

If the DPP authentication response frame is not received until a predetermined time elapses according to the above assumption, step S623 is performed for retransmission of the DPP authentication response frame.

In operation S623, the first wireless device 610 may retransmit the DPP authentication request frame to the second wireless device 620. Subsequently, the first wireless device 610 may determine whether the DPP authentication response frame is received from the second wireless device 620 within a predetermined time in response to the DPP authentication request frame resent in step S623.

For example, the predetermined time may be set based on a transmission time of the DPP authentication request frame in step S623.

For clarity and concise description of FIG. 6, it may be assumed that a DPP authentication response frame is received from the second wireless device 620 within a predetermined time. According to the above assumption, if a DPP authentication response frame is received before a predetermined time elapses, step S624 is performed.

In operation S624, the first wireless device 610 may receive a DPP authentication response frame from the second wireless device 620 in response to the DPP authentication request frame resent in operation S623.

In operation S625, the first wireless device 610 may transmit a DPP authentication confirmation frame to the second wireless device 620 to complete the DPP authentication protocol.

When the DPP authentication protocol S620 is successfully performed according to the transmission of the DPP authentication confirmation frame, a secure channel may be established between the initiator (or configurator) and the responder (or registrant).

In operation S630, the first wireless device 610 and the second wireless device 620 may perform a DPP configuration protocol.

In operation S630, the first wireless device 610 and the second wireless device 620 may use the same MAC address. In operation S630, the first wireless device 610 and the second wireless device 620 may use the same channel used during the DPP authentication protocol.

In operation S631, to start the DPP configuration protocol, the second wireless device 620 may transmit a DPP configuration request frame to the first wireless device 610. Here, regardless of whether the initiator or responder plays the role of the configurator, the DPP configuration request frame can be sent only by the enrollee.

In operation S632, the first wireless device 610 may transmit a DPP configuration response frame to the second wireless device 620 in response to the DPP configuration request frame. The DPP configuration response frame may include a DPP configuration object. For example, the DPP configuration object may include a plurality of parameter information as shown in Table 1 below.

When the aforementioned steps S610 to S630 are successfully performed, network information of the WLAN system including an AP (not shown) previously associated with the first wireless device 610 is displayed in the second wireless device 620. Can be forwarded to For example, the network information may include SSID information or password information.

That is, the second wireless device 620 may be connected to the first wireless device 610 without performing an association procedure with an AP (not shown) coupled to the first wireless device 610. It may be connected to the WLAN system based on the network information received from 610.

The first AP 710 and the second AP 720 may be included in the WLAN system 700 corresponding to one ESS. That is, the first AP 710 and the second AP 720 may be set to have the same SSID.

The first AP 710 may manage the first coverage BSS_coverage # 1 for the first BSS. That is, the first AP 710 may communicate with an STA (not shown) located in the first coverage BSS_coverage # 1 based on the first BSSID.

For example, the first AP 710 may transmit a frame including the first BSSID to the STA coupled to the first AP 710 in the first coverage. In addition, the first AP 710 may receive a frame including the first BSSID from the STA coupled with the first AP 710 in the first coverage.

The second AP 720 may manage the second coverage BSS_coverage # 2 for the second BSS. That is, the second AP 720 may communicate with an STA (not shown) located in the second coverage BSS_coverage # 2 based on the second BSSID.

For example, the second AP 720 may transmit a frame including the second BSSID to the STA coupled to the second AP 720 in the second coverage. In addition, the second AP 720 may receive a frame including the second BSSID from the STA coupled with the second AP 720 in the second coverage.

Referring to FIG. 7, the wireless device may be initially coupled with the first AP 710 at the first location A. FIG.

For example, when the wireless device moves from the first position A to the second position B, the wireless device may remain in association with the first AP 710. That is, even if the wireless device is in the second position B that is relatively closer to the second AP 720 than the first AP 710, the second AP (as long as the wireless device maintains association with the first AP 710). It is not possible to communicate with 720).

Accordingly, the first AP 710 may terminate initial association with the wireless device in consideration of the movement of the wireless device, and perform a handover (or client steering) operation so that the wireless device may be reunited with the second AP 720. Can be.

For example, in a handover operation, when the wireless device is rejoined with another AP, the initial AP may communicate information to the wireless device about the operating band and operating channel to use with the AP to be recombined.

When the handover operation is performed according to the movement of the wireless device, the wireless device may be recombined with the second AP 720.

Hereinafter, in the present specification, an AP in charge of controlling a multi AP may be referred to as a multi-AP controller. In addition, an AP connected to a multi-AP controller among a plurality of APs included in the WLAN system may be referred to as a multi-AP agent.

In addition, a wireless device connected to a multi-AP controller or a multi-AP agent to receive Internet service may be referred to as a client. According to the handover operation, the multi-AP agent to which the client will be rejoined may be referred to as a target AP.

8 is a diagram illustrating a handover procedure of a wireless device supporting a BTS (BSS Transition Management) function. 8 is described on the premise that the client 820 is a wireless device initially coupled with the multi-AP agent 810.

In consideration of the movement of the client 820 toward the target AP 830, the multi-AP agent 810 may decide to steer (or handover) the client 820 to the target AP 830.

The multi-AP agent 810 may transmit a BTM request frame to the client 820.

For example, the BTM request frame may include information about the BSSID of the target AP 830, information about an operating class of the target AP 830, and information about a channel of the target AP 830. . For example, the client 820 may obtain information about the target AP based on the BTM request frame.

That is, as shown in FIG. 8, in the case of the wireless device supporting the BTM function, information on the target AP may be directly transmitted to the client.

If the BTM request frame is successfully received, in response to the BTM request frame, the client 820 may transmit the BTM response frame to the multi-AP agent 810. Here, the BTM response frame may include a BTM status code.

For example, when the client 820 determines to recombine with the target AP based on the information included in the BTM request frame, the BTM status code may include 'Accept' information.

As another example, when the client 820 determines not to recombine with the target AP based on the information included in the BTM request frame, the BTM status code may include 'Reject' information.

Subsequently, the client 820 may transmit a recombination request frame to the target AP 830. If successfully received for the recombination request frame, in response to the recombination request frame, the target AP 830 may transmit a recombination response frame to the client 820.

9 is a diagram illustrating a handover procedure of a wireless device that does not support the BTM function. 9 may be described on the premise that the multi-AP controller 910 controls the multi-AP agent 920.

The multi-AP controller 910 may transmit a client association control request message to the multi-AP agent 920.

If the client association control request message is successfully received, in response to the client association control request message, the multi-AP agent 920 may forward an ACK message to the multi-AP controller 910. For example, the multi-AP controller 910 may determine whether to perform a joining procedure with a client based on the client joining control request message.

The multi-AP agent 920 may receive a join request frame from the client 930. For example, the multi-AP agent 920 may decide not to steer (or handover) the client 930 based on the client association control request message.

Accordingly, the multi-AP agent 920 may transmit a combined response frame including 'reject' information to the client 930 to the client 930.

That is, as shown in FIG. 9, in the case of a wireless device that does not support the BTM function, information about the target AP may not be directly transmitted to the client.

Hereinafter, a method for directly transferring information on a target AP in a handover operation for a wireless device that does not support the BTM function will be described.

The WLAN system according to the present embodiment may include a multi-AP controller 1010, a first multi-AP agent 1020, a client 1030, and a second multi-AP agent 1040.

The multi-AP controller 1010 of FIG. 10 may control the first multi-AP agent 1020 and the second multi-AP agent 1040.

For example, the multi-AP controller 1010 may receive information about a client coupled to each of the

multi-AP agents

1020 and 1040 from each of the

multi-AP agents

1020 and 1040. Accordingly, the multi-AP controller 1010 may manage information about all clients coupled to each of the

multi-AP agents

1020 and 1040.

The multi-AP controller 1010 may be collocated with the first multi-AP agent 1020 as one wireless device. Alternatively, the multi-AP controller 1010 may be collocated with the second multi-AP agent 1040 as one wireless device.

It can be understood that the first multi-AP agent 1020 and the second multi-AP agent 1040 are in the same ESS. In this case, the first multi-AP agent 1020 and the second multi-AP agent 1040 have the same SSID.

The first multi-AP agent 1020 of FIG. 10 may serve as a DPP configurator. The first multi-AP agent 1020 may manage first coverage for the first BSS.

For example, the first multi-AP agent 1020 may communicate with at least one wireless device coupled with the first multi-AP agent 1020 in a frame with a first BSSID within the first coverage.

The client 1030 of FIG. 10 may serve as a DPP enrollee. The client 1030 may initially be understood as a wireless device coupled with the first multi-AP agent 1020 within the first BSS area. The client 1030 may be understood as a wireless device (ie, a non BTM support client) that does not support the BTM function mentioned earlier in FIG. 9.

The second multi-AP agent 1040 of FIG. 10 may be a target AP. The second multi-AP agent 1040 may manage the second coverage for the second BSS.

For example, the second multi-AP agent 1040 may communicate with at least one wireless device coupled with the second multi-AP agent 1040 in a frame with a second BSSID within the second coverage.

Referring to FIG. 10, the client 1030 may be initially coupled with the first multi-AP agent 1020 within the first coverage. Subsequently, while the client 1030 remains in association with the first multi-AP agent 1020, the client 1030 may move toward a second coverage close to the second multi-AP agent 1040.

In operation S1010, as the client 1030 moves, the first multi-AP agent 1020 transfers the client 1030 coupled with the first multi-AP agent 1020 to the second multi-AP agent 1040. You may decide to handover.

For example, when the strength of the wireless signal received from the client 1030 is less than a preset threshold, the first multi-AP agent 1020 hands the client 1030 to the second multi-AP agent 1040. You may decide to over.

From the perspective of the client 1030, the client 1030 may compare the strength of the wireless signal received from the first multi-AP agent 1020 with the strength of the wireless signal received from the second multi-AP agent 1040. .

If the strength of the wireless signal received from the second multi-AP agent 1040 may be greater than the strength of the wireless signal received from the first multi-AP agent 1020. In this case, the client 1030 may decide to disassociate with the first multi-AP agent 1020. In addition, the client 1030 may decide to re-associate with the second multi-AP agent 1040.

Steps S1020 and S1030 of FIG. 10 may correspond to a DPP configuration protocol (eg, S630 of FIG. 6) of the DPP procedure of FIG. 6. Steps S1020 and S1030 of FIG. 10 are described on the assumption that the DPP bootstrap protocol (eg, S610 of FIG. 6) and the DPP authentication protocol (eg, S620 of FIG. 6) are successfully performed during the DPP procedure.

In operation S1020, the first multi-AP agent 1020 may receive a DPP configuration request frame from the client 1030. Here, the DPP configuration request frame of FIG. 10 may be understood as a frame for starting the DPP configuration protocol as mentioned through step S631 of FIG. 6.

In operation S1030, the first multi-AP agent 1020 may transmit a DPP configuration response frame in response to the DPP configuration request frame.

Here, the DPP configuration response frame may be a frame for recommending that the client 1030 terminate the association with the first multi-AP agent 1020 and associate with the second multi-AP agent 1040.

Here, the DPP configuration response frame of FIG. 10 may include a DPP configuration object as mentioned through step S632 of FIG. 6.

According to the present embodiment, the DPP configuration object may include a plurality of parameter information as shown in Table 2 below.

Referring to Table 2, a steering object to be used for the handover operation may include a string for 'Target BSSID', a string for 'Band' and a string for 'channel'.

According to the present embodiment, the DPP configuration response frame may include information about a target BSSID (Basic Service Set Identifier) for the second multi-AP agent 1040 that is the target AP.

In addition, the DPP configuration response frame may include information about a frequency band to which the client 1030 is connected with the second multi-AP agent 1040. In addition, the DPP configuration response frame may include information about a channel to which the client 1030 is connected with the second multi-AP agent 1040.

In operation S1040, the first multi-AP agent 1020 may disassociate with the client 1030.

In operation S1050, the client 1030 may be associated with the second multi-AP agent 1040 without a separate association procedure based on the information on the target BSSID included in the DPP configuration response frame.

In addition, the client 1030 may include information about the target BSSID included in the DPP configuration response frame, information about a frequency band to be connected to the second multi-AP agent 1040, and a channel to be connected to the second multi-AP agent 1040. It may be associated with the second multi-AP agent 1040 without a separate association procedure based on the related information.

According to the present embodiment, when a handover operation is required in accordance with the movement of a wireless device in a WLAN network including multiple APs, even if the wireless device does not support the BTM function, the wireless device precombines information about the target AP. Can be obtained directly from the AP. Accordingly, the wireless device may be combined with the target AP without a separate combining procedure.

Referring to FIG. 11, the client 1130 may be initially coupled with the first multi-AP agent 1120 within the first coverage. Subsequently, while the client 1130 remains engaged with the first multi-AP agent 1120, the client 1130 may move toward a second coverage close to the second multi-AP agent 1140.

In step S1110, the DPP procedure may be performed. A description of the DPP procedure of FIG. 11 may be understood as the contents described with reference to FIG. 6.

In operation S1120, as the client 1130 moves, the first multi-AP agent 1120 moves the client 1130 coupled with the first multi-AP agent 1120 to the second multi-AP agent 1140. You may decide to handover.

In operation S1130, the first multi-AP agent 1120 may transmit a DPP inquiry request frame to the client 1130.

That is, the DPP query request frame is a frame for recommending that the client 1130 terminate the association with the first multi-AP agent 1120 and associate with the second multi-AP agent 1140 which is the target AP. Can be.

The DPP query request frame of FIG. 11 may include a steering information attribute as shown in Table 3 below.

Referring to Table 3, an attribute body field may include a plurality of parameter information as shown in Table 4 below.

In operation S1140, the client 1130 that receives the steering information attribute through the DPP query request frame may transmit the DPP query response frame to the first multi-AP agent 1120.

In operation S1150, the first multi-AP agent 1120 may disassociate with the client 1130.

In operation S1160, the client 1130 may be associated with the second multi-AP agent 1140 without a separate combining process based on the information on the target BSSID included in the DPP query request frame.

The first multi-AP agent 1220 of FIG. 12 may serve as a DPP enrollee.

The first multi-AP agent 1220 may manage first coverage for the first BSS. For example, the first multi-AP agent 1220 may communicate with at least one wireless device coupled with the first multi-AP agent 1220 in a frame with a first BSSID within the first coverage.

The client 1230 of FIG. 12 may serve as a DPP configurator. The client 1230 may initially be understood as a wireless device coupled with the first multi-AP agent 1220 within the first BSS area. The client 1230 may be understood as a wireless device (ie, a non BTM support client) that does not support the BTM function mentioned in FIG. 9 above.

The second multi-AP agent 1240 of FIG. 12 may be a target AP. The second multi-AP agent 1240 may manage the second coverage for the second BSS.

For example, the second multi-AP agent 1240 may communicate with at least one wireless device coupled with the second multi-AP agent 1240 in a frame with a second BSSID within the second coverage.

Referring to FIG. 12, the client 1230 may be initially coupled with the first multi-AP agent 1220 within first coverage. Subsequently, while the client 1230 remains in association with the first multi-AP agent 1220, the client 1230 may move toward a second coverage close to the second multi-AP agent 1240.

In step S1210, the DPP procedure may be performed. A description of the DPP procedure of FIG. 12 may be understood as the contents described with reference to FIG. 6.

In operation S1220, as the client 1230 moves, the first multi-AP agent 1220 moves the client 1230 coupled with the first multi-AP agent 1220 to the second multi-AP agent 1240. You may decide to handover.

In operation S1230, the client 1230 may transmit a DPP inquiry request frame to the first multi-AP agent 1220.

Here, the DPP query request frame is a frame for querying the first multi-AP agent 1220 whether the client 1230 is suitable for newly combining with the second multi-AP agent 1240 which is the target AP. Can be.

In operation S1240, in response to the DPP query request frame, the first multi-AP agent 1220 may transmit a DPP query response frame to the client 1230.

Here, the DPP query response frame may be a frame for recommending to the client 1230 to disassociate with the first multi-AP agent 1220 and to associate with the second multi-AP agent 1240.

The DPP query response frame of FIG. 12 may include steering information attributes and a plurality of parameter information as shown in Tables 3 and 4.

In operation S1250, the first multi-AP agent 1220 may disassociate with the client 1230.

In operation S1260, the client 1230 may be associated with the second multi-AP agent 1240 without a separate association procedure based on the information on the target BSSID included in the DPP query response frame.

Referring to FIG. 13, the wireless device may be an STA or an AP or a non-AP STA that may implement the above-described embodiment. In addition, the wireless device may correspond to the above-described user, or may correspond to a transmitting terminal for transmitting a signal to the user.

The wireless device of FIG. 13 includes a processor 1310, a memory 1320, and a transceiver 1330 as shown. The illustrated processor 1310, the memory 1320, and the transceiver 1330 may be implemented as separate chips, or at least two blocks / functions may be implemented through one chip.

The transceiver 1330 is a device including a transmitter and a receiver. When a specific operation is performed, only one of the transmitter and the receiver may be performed, or both the transmitter and the receiver may be performed. have.

The transceiver 1330 may include one or more antennas for transmitting and / or receiving wireless signals. In addition, the transceiver 1330 may include an amplifier for amplifying the reception signal and / or the transmission signal and a bandpass filter for transmission on a specific frequency band.

The processor 1310 may implement the functions, processes, and / or methods proposed herein. For example, the processor 1310 may perform an operation according to the above-described exemplary embodiment. That is, the processor 1310 may perform the operations disclosed in the embodiments of FIGS. 1 to 12.

The processor 1310 may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a data processing device, and / or a converter for mutually converting baseband signals and wireless signals.

The memory 1320 may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium, and / or other storage device.

For convenience of description, an example of FIG. 14 is described based on a block for a transmission signal, but it is obvious that the reception signal can be processed using the block.

The illustrated data processor 1410 generates transmission data (control data and / or user data) corresponding to the transmission signal. The output of the data processor 1410 may be input to the encoder 1420. The encoder 1420 may perform coding through a binary convolutional code (BCC) or a low-density parity-check (LDPC) technique. At least one encoder 1420 may be included, and the number of encoders 1420 may be determined according to various information (for example, the number of data streams).

The output of the encoder 1420 may be input to the interleaver 1430. The interleaver 1430 distributes a continuous bit signal over radio resources (eg, time and / or frequency) to prevent burst errors due to fading or the like. At least one interleaver 1430 may be included, and the number of the interleaver 1430 may be determined according to various information (for example, the number of spatial streams).

The output of the interleaver 1430 may be input to a constellation mapper 1440. The constellation mapper 1440 performs constellation mapping such as biphase shift keying (BPSK), quadrature phase shift keying (QPSK), quadrature amplitude modulation (n-QAM), and the like.

The output of the constellation mapper 1440 may be input to the spatial stream encoder 1450. The spatial stream encoder 1450 performs data processing to transmit the transmission signal through at least one spatial stream. For example, the spatial stream encoder 1450 may perform at least one of space-time block coding (STBC), cyclic shift diversity (CSD) insertion, and spatial mapping on a transmission signal.

The output of the spatial stream encoder 1450 may be input to an IDFT 1460 block. The IDFT 1460 block performs an inverse discrete Fourier transform (IDFT) or an inverse Fast Fourier transform (IFFT).

The output of the IDFT 1460 block is input to the Guard Interval (GI) inserter 1470, and the output of the GI inserter 1470 is input to the transceiver 1330 of FIG. 13.

In the detailed description of the present specification, specific embodiments have been described, but various modifications are possible without departing from the scope of the present specification. Therefore, the scope of the present specification should not be limited to the above-described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims of the present invention.

Claims

In a method for delivering information on a target access point (AP) in a WLAN system,

When the wireless device associated with the first AP moves toward the second coverage of the second AP within the first coverage of the first AP, the first AP hands over the wireless device to the second AP. Determining to:

Receiving, by the first AP, a Device Provisioning Protocol (DPP) request frame from the wireless device; And

The first AP transmits a DPP setup response frame to the wireless device in response to the DPP setup request frame, wherein the DPP setup response frame includes a target basic service set identifier (BSSSID) for the second AP. A method comprising the steps.
According to claim 1,

After the transmission of the DPP setup response frame, the first AP further dis-associates with the wireless device.
According to claim 1,

The DPP setup response frame further includes information about a frequency band to which the wireless device will connect with the second AP and information about a channel through which the wireless device will connect with the second AP.
According to claim 1,

The first AP and the second AP is controlled by a multi-AP controller included in the WLAN system.
According to claim 1,

And determining to hand over the wireless device to the second AP is performed when the signal received from the wireless device is less than a strength and a preset threshold.
According to claim 1,

The first AP communicates with at least one STA associated with the first AP within the first coverage based on a first BSSID,

The second AP communicates with at least one STA coupled with the second AP within the second coverage based on a second BSSID.
The method of claim 6,

The target BSSID corresponds to the second BSSID,

The same Service Set Identifier (SSID) is configured for the first AP and the second AP.
The method of claim 6,

The wireless device is coupled with the second AP based on the target BSSID without a separate joining procedure.
In a first AP performing a method for delivering information on a target access point (AP) in a WLAN system, the first AP,

A transceiver for transmitting and receiving a radio signal; And

A processor coupled to the transceiver, wherein the processor includes:

And when the wireless device associated with the first AP moves within the first coverage of the first AP toward the second coverage of the second AP, determines to handover the wireless device to the second AP. ,

Is configured to receive a Device Provisioning Protocol (DPP) setup request frame from the wireless device,

And a DPP setup response frame to the wireless device in response to the DPP setup request frame, wherein the DPP setup response frame includes a target Basic Service Set Identifier (BSSID) for the second AP.
The method of claim 9,

The DPP setup response frame further includes information about a frequency band to which the wireless device is to be connected with the second AP and information about a channel to which the wireless device is to be connected to the second AP.