KR102074926B1 - Method for allocating channel in wireless local area network and apparatus for the same - Google Patents

Abstract

Disclosed are a channel allocation method and apparatus in a WLAN. The channel setting method may include receiving a first frame including scheduling information for a first interval from a second access point, and a second including resource related information required for transmission and reception through a second interval subsequent to the first interval. Generating a frame and transmitting a second frame to a second access point. Therefore, the performance of the WLAN can be improved.

Description

Method and device for allocating channel in WLAN {METHOD FOR ALLOCATING CHANNEL IN WIRELESS LOCAL AREA NETWORK AND APPARATUS FOR THE SAME}

The present invention relates to a WLAN technology, and more particularly, to a channel allocation technology in an overlapping basic service set (OBSS).

With the development of information and communication technology, various wireless communication technologies are being developed. Wireless local area network (WLAN) is based on radio frequency technology, personal digital assistant (PDA), laptop computer, portable multimedia player (PMP), smart It is a technology for wirelessly accessing the Internet in a home, business, or a specific service providing area by using a portable terminal such as a smart phone or a tablet PC.

The standard for WLAN technology is being developed as an Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. The WLAN technology according to the IEEE 802.11a standard operates based on orthogonal frequency division multiplexing (OFDM), and may provide a transmission rate of up to 54 Mbps in a 5 GHz band. The WLAN technology according to the IEEE 802.11b standard operates based on a direct sequence spread spectrum (DSSS) scheme and can provide a transmission rate of up to 11 Mbps in the 2.4 GHz band. The WLAN technology based on the IEEE 802.11g standard operates based on the OFDM scheme or the DSSS scheme and may provide a transmission rate of up to 54 Mbps in the 2.4 GHz band.

The WLAN technology according to the IEEE 802.11n standard operates in the 2.4 GHz band and the 5 GHz band based on the OFDM scheme, and uses four spatial streams when the multiple input multiple output OFDM (MIMO-OFDM) scheme is used. It can provide a transmission rate of up to 300Mbps for spatial streams. Wireless LAN technology according to the IEEE 802.11n standard can support a channel bandwidth (channel bandwidth) up to 40MHz, in this case can provide a transmission rate of up to 600Mbps.

As the spread of the WLAN is activated and applications using the same are diversified, there is an increasing need for a new WLAN technology for supporting a higher throughput than the data processing speed supported by IEEE 802.11n. Very high throughput (VHT) WLAN technology is one of the IEEE 802.11 WLAN technologies that have been proposed to support data processing speeds of 1 Gbps or more. Among them, IEEE 802.11ac is being developed as a standard for providing very high throughput in the band below 5 GHz, and IEEE 802.11ad is being developed as a standard for providing very high throughput in the 60 GHz band.

Recently, as the use of WLAN increases, the possibility of using overlapping channels between neighbor access points (or neighbor BSSs) is increasing. Since overlapping channels are used between neighboring BSSs, there is a problem that the performance of the WLAN is degraded.

The name of the invention of US2016 / 0381702A1 is “CHANNEL ACCESS METHOD AND DEVICE IN WIRELESS LAN SYSTEM”. The priority date is July 2, 2013, and was released on December 29, 2016.

An object of the present invention for solving the above problems is to provide a method for allocating channels in consideration of overlapping channels between neighboring BSSs.

Another object of the present invention for solving the above problems is to provide an apparatus for allocating channels in consideration of overlapping channels between neighboring BSSs.

In accordance with an aspect of the present invention, there is provided a channel setting method performed by a first access point, the method comprising: receiving a first frame including scheduling information about a first interval from a second access point, Generating a second frame including resource related information required for transmission and reception through a second interval subsequent to the first interval, and transmitting the second frame to the second access point.

Here, the first frame may be a beacon frame.

Here, the first frame may include duration information indicating a transmission start time of the first frame to the transmission end time of the second frame.

Here, the first frame may include limited access window information indicating a transmission period of the second frame.

Here, the first frame may be received at the start of the first interval.

Here, the scheduling information may include at least one of an operation channel and a transmission interval of the first access point during the first interval.

Here, the resource related information may include at least one of expected duration information required for frame transmission and reception through the second interval, a data rate at the first pre-interval, and a transmission failure rate for each bandwidth at the pre-first interval. It may include.

Here, in the transmitting of the second frame to the second access point, when the poll frame is received from the second access point, the second frame may be transmitted to the second access point.

The channel setting method may further include transmitting and receiving a frame with at least one terminal connected to the first access point within an operation channel and a transmission interval indicated by the scheduling information.

According to another aspect of the present invention, there is provided a channel management method performed in a second access point, the method including generating a first frame including scheduling information for a first interval, and generating the first frame. Transmitting to the access point and receiving a second frame from the first access point, the second frame including resource related information required for transmission and reception over a second interval subsequent to the first interval.

Here, the first frame may be a resource allocation frame.

Here, the first frame may be transmitted to the first access point after the beacon frame of the second access point is transmitted.

Here, the scheduling information may include at least one of an operation channel and a transmission interval of the first access point during the first interval.

Here, the resource related information may include at least one of expected duration information required for frame transmission and reception through the second interval, a data rate at the first pre-interval, and a transmission failure rate for each bandwidth at the pre-first interval. It may include.

The channel management method may further include generating scheduling information for the second interval based on the resource related information.

A first access point according to an embodiment of the present invention for achieving the another object includes a processor and a memory in which at least one instruction executed through the processor is stored, wherein the at least one instruction is a second access point. Receiving a first frame including scheduling information with respect to a first interval from the second frame; generating a second frame including resource related information required for transmission and reception through a second interval subsequent to the first interval; And send two frames to the second access point.

Here, the scheduling information may include at least one of an operation channel and a transmission interval of the first access point during the first interval.

Here, the resource related information may include at least one of expected duration information required for frame transmission and reception through the second interval, a data rate at the first pre-interval, and a transmission failure rate for each bandwidth at the pre-first interval. It may include.

Here, in the transmitting of the second frame to the second access point, when the resource allocation frame is received from the second access point, the second frame may be transmitted to the second access point.

Here, the at least one command may be executable to further transmit and receive a frame with at least one terminal connected to the first access point within an operation channel and a transmission interval indicated by the scheduling information.

According to the present invention, the performance of the WLAN can be improved.

1 is a block diagram illustrating one embodiment of a station for performing methods in accordance with the present invention.
2 is a conceptual diagram illustrating an embodiment of a configuration of a wireless LAN system according to IEEE 802.11.
3 is a conceptual diagram illustrating an OBSS.
4 is a conceptual diagram illustrating a method of allocating non-overlapping channels to BSSs.
5 is a conceptual diagram illustrating a method of performing coordination for a transmission interval when the same channel is allocated to BSSs.
6 is a conceptual diagram illustrating a channel wasted in the existing WLAN.
7 is a conceptual diagram illustrating an embodiment of a method of performing coordination on an overlapping channel.
8 is a conceptual diagram illustrating a channel allocation method according to an embodiment of the present invention.
9 is a conceptual diagram illustrating a channel allocation method according to another embodiment of the present invention.
10 is a conceptual diagram illustrating an embodiment of a resource allocation element.
11 is a block diagram illustrating an embodiment of a resource allocation feedback frame.

As the present invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description.

However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is said to be "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that another component may be present in the middle. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present disclosure does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. In the following description of the present invention, the same reference numerals are used for the same elements in the drawings and redundant descriptions of the same elements will be omitted.

Throughout the specification, a station (STA) is a physical layer for medium access control (MAC) and wireless medium that conforms to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. By any functional medium that includes an interface. The station STA may be divided into a station that is an access point (AP) and a station that is a non-access point (STA). A station (STA), which is an access point (AP), may simply be called an access point (AP), and a station (STA), which is a non-access point (AP), may simply be called a terminal.

The station STA may include a processor and a transceiver, and may further include a user interface and a display device. The processor refers to a unit designed to generate a frame to be transmitted through a wireless network or to process a frame received through the wireless network, and may perform various functions for controlling a station (STA). A transceiver is a unit that is functionally connected to a processor and is designed to transmit and receive a frame through a wireless network for a station (STA).

The access point (AP) may be a centralized controller, a base station (BS), a radio access station, a node B, an evolved node B, a relay, and a mobile MMR. multihop relay (BS) -BS, base transceiver system (BTS), or site controller, and the like, and may include some or all of their functionality.

A terminal (ie, a non-access point) may be a wireless transmit / receive unit (WTRU), a user equipment (UE), a user terminal (UT), an access terminal (AT), Refers to a mobile station (MS), a mobile terminal, a subscriber unit, a subscriber station (SS), a wireless device, or a mobile subscriber unit And may include some or all of the functionality thereof.

Here, the terminal may be a desktop computer, a laptop computer, a tablet PC, a wireless phone, a mobile phone, a smart phone, a smart watch capable of communication. (smart watch), smart glass, e-book reader, portable multimedia player (PMP), portable gaming device, navigation device, digital camera, digital multimedia broadcasting (DMB) player, digital voice Digital audio recorder, digital audio player, digital picture recorder, digital picture player, digital video recorder, digital video player ) May be used.

1 is a block diagram illustrating one embodiment of a station for performing methods in accordance with the present invention.

Referring to FIG. 1, the station 100 may include at least one processor 110, a memory 120, and a network interface device 130 connected to a network to perform communication. In addition, the station 100 may further include an input interface device 140, an output interface device 150, a storage device 160, and the like. Each component included in the station 100 may be connected by a bus 170 to communicate with each other.

The processor 110 may execute a program command stored in the memory 120 and / or the storage device 160. The processor 110 may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the methods according to the present invention are performed. The memory 120 and the storage device 160 may be configured of a volatile storage medium and / or a nonvolatile storage medium. For example, the memory 120 may be configured as read only memory (ROM) and / or random access memory (RAM).

Embodiments of the present invention are applied to a WLAN system according to IEEE 802.11, and can be applied to other communication systems as well as a WLAN system according to IEEE 802.11.

For example, embodiments of the present invention may include a mobile Internet, a global system such as a wireless personal area network (WPAN), a wireless body area network (WBAN), a wireless broadband internet (WiBro), or a world interoperability for microwave access (WiMax). 2G mobile networks such as for mobile communication or code division multiple access (CDMA), 3G mobile networks such as wideband code division multiple access (WCDMA) or cdma2000, high speed downlink packet access (HSDPA) or high speed uplink 3.5G mobile communication network such as packet access, 4G mobile communication network such as long term evolution (LTE) or LTE-Advanced, 5G mobile communication network and the like.

2 is a conceptual diagram illustrating an embodiment of a configuration of a wireless LAN system according to IEEE 802.11.

Referring to FIG. 2, a WLAN system according to IEEE 802.11 may include at least one basic service set (BSS). BSS means a set of stations (STA1, STA2 (AP1), STA3, STA4, STA5 (AP2), STA6, STA7, STA8) that can be successfully synchronized and communicate with each other, and does not mean a specific area. .

BSS can be classified into infrastructure BSS (Independent BSS) and Independent BSS (IBSS). Here, BSS1 and BSS2 mean infrastructure BSS, and BSS3 means IBSS.

The BSS1 is a distribution system connecting a first terminal STA1, a first access point STA2 (AP1) providing a distribution service, and a plurality of access points STA2 (AP1), STA5 (AP2) ( distribution system (DS). In BSS1, the first access point STA2 (AP1) may manage the first terminal STA1.

The BSS2 connects a third terminal STA3, a fourth terminal STA4, a second access point STA5 (AP2) providing a distribution service, and a plurality of access points STA2 (AP1) and STA5 (AP2). It may include a distribution system (DS). In BSS2, the second access point STA5 (AP2) may manage the third terminal STA3 and the fourth terminal STA4.

BSS3 refers to IBSS operating in ad-hoc mode. There is no access point in BSS3, which is a centralized management entity. That is, in BSS3, the terminals STA6, STA7, and STA8 are managed in a distributed manner. In BSS 3, all of the terminals STA6, STA7, and STA8 may refer to mobile terminals, and thus, are not allowed to be connected to the distribution system DS, thereby forming a self-contained network.

The access points STA2 (AP1) and STA5 (AP2) may provide access to the distributed system DS through the wireless medium for the terminals STA1, STA3, and STA4 coupled thereto. In BSS1 or BSS2, communication between terminals STA1, STA3, and STA4 is generally performed through access points STA2 (AP1) and STA5 (AP2), but when a direct link is established, the terminals ( Direct communication between STA1, STA3, and STA4 is possible.

The plurality of infrastructure BSSs may be interconnected through a distribution system (DS). A plurality of BSSs connected through a distribution system (DS) is referred to as an extended service set (ESS). The entities included in the ESS (STA1, STA2 (AP1), STA3, STA4, STA5 (AP2)) can communicate with each other, any terminal (STA1, STA3, STA4) in the same ESS while communicating seamlessly one You can move from one BSS to another BSS.

The distribution system (DS) is a mechanism for one access point to communicate with another access point, whereby the access point transmits a frame or moves to another BSS for terminals coupled to a BSS that it manages. A frame may be transmitted for any terminal. In addition, the access point may transmit and receive frames with an external network such as a wired network. Such a distribution system (DS) does not necessarily need to be a network, and there is no limitation on its form as long as it can provide certain distribution services specified in the IEEE 802.11 standard. For example, the distribution system may be a wireless network such as a mesh network or a physical structure that connects access points to each other.

Recently, the use of the WLAN is rapidly increasing, the problem caused by the overlapping BSS (OBSS) has become serious. In the area where the access points are dense, the performance of the WLAN may be degraded due to collisions between the BSSs due to overlap between the BSSs, contention competition between the stations, and the like. In particular, more collisions occur between BSSs using the same channel, and different channels may be allocated to neighboring BSSs to prevent such collisions. When different channels are allocated to neighboring BSSs, collisions do not occur between neighboring BSSs, and stations belonging to each of the neighboring BSSs can transmit and receive independently of each other. To this end, when the access point newly establishes a BSS, the access point should set up a channel of its BSS so as not to overlap with a channel of neighboring BSSs. In addition, the access point should change its channel as needed when interference is caused by the BSS newly set by the neighboring access point.

While the number of channels that can be used in a WLAN is limited, the number of access points is rapidly increasing. Therefore, it is not easy for a channel to be allocated such that neighboring access points use a channel that does not overlap each other. In practice, channels may overlap between neighboring access points, in which case the probability of simultaneous transmission of neighboring access points depends on which channel is assigned to each neighboring access point and which channel is set as the primary channel. Can vary. In particular, when a narrow band is allocated to enable simultaneous transmission of stations within neighboring BSSs, the performance of the WLAN may be improved by simultaneous transmission over the narrow band.

When overlapping channels are used between neighboring BSSs, resource utilization may be improved if resources are allocated such that transmission through narrowband is performed within the same time interval. According to the IEEE 802.11 standard, a station can access a channel and transmit a frame through contention in a distributed manner. In this environment, it is impossible to schedule resources so that transmission over narrowband is performed within the same time period.

In the following, a method of allocating a channel in consideration of an overlapping channel between neighboring BSSs will be described in detail.

3 is a conceptual diagram illustrating an OBSS.

Referring to FIG. 3, a first access point AP1 may set BSS1, a second access point AP2 may set BSS2, a third access point AP3 may set BSS3, and a fourth The access point AP4 may set BSS4, and the fifth access point AP5 may set BSS5. When the access points AP1, AP2, AP3, AP4, and AP5 use the same channel, a lot of channel access contention and frame collision occurs in an overlapped area between the access points AP1, AP2, AP3, AP4, and AP5. Can be. Accordingly, performance of the WLAN may be degraded.

The following methods can be used to mitigate channel access contention and frame collisions.

How to assign non-overlapping channels to BSSs

In case of allocating the same channel to BSSs, a method of coordination is performed so that transmission intervals do not overlap between BSSs.

-If a non-overlapping channel is allocated to BSSs as much as possible but the number of channels is insufficient, the overlapping channel is generated.

How to assign a non-overlapping channel to BSSs

4 is a conceptual diagram illustrating a method of allocating non-overlapping channels to BSSs.

Referring to FIG. 4, the first access point AP1 to set the BSS1 may identify the empty channels CH0 to CH11 through a scanning procedure. The first access point AP1 may set BSS1 to operate in the channels CH0 to CH3 among the empty channels CH0 to CH11. The second access point AP2 intending to set the BSS2 may check the empty channels CH4 to CH11 through a scanning procedure. The second access point AP2 may set the BSS2 to operate in the channels CH4 to CH7 among the empty channels CH4 to CH11. The third access point AP3 intending to set the BSS3 may check the empty channels CH8 to CH11 through a scanning procedure. The third access point AP3 may set BSS3 to operate on the empty channels CH8 to CH11. Accordingly, each of the access points AP1, AP2, and AP3 may transmit and receive a frame without interference by other access points.

Meanwhile, the hidden access point may not be detected in the scanning procedure. In this case, each of the access points AP1, AP2, and AP3 may establish a BSS without confirming the existence of the hidden access point. Each of the access points AP1, AP2, and AP3 is not interfered by transmission and reception of a hidden access point. However, the terminal connected to each of the access points AP1, AP2, and AP3 may be located in the BSS set by the hidden access point. In this case, the terminal connected to each of the access points AP1, AP2, and AP3 may be interfered with by the transmission and reception of the hidden access point.

If the same channel is allocated to BSSs, a method of coordinating so that transmission intervals do not overlap between BSSs

When there are not many empty channels and the same channels are allocated to the BSSs, coordination of transmission intervals between the BSSs is necessary to alleviate channel access contention and frame collisions in the BSSs. That is, when a station belonging to each of the BSSs transmits and receives a frame at different times, channel access contention and frame collision can be alleviated.

5 is a conceptual diagram illustrating a method of performing coordination for a transmission interval when the same channel is allocated to BSSs.

Referring to FIG. 5, the first access point AP1 to set the BSS1 may check the empty channels CH0 to CH7 through a scanning procedure. The first access point AP1 may set BSS1 to operate in the channels CH0 to CH3 among the empty channels CH0 to CH7. The second access point AP2 intending to set the BSS2 may check the empty channels CH4 to CH7 through a scanning procedure. The second access point AP2 may set the BSS2 to operate on the empty channels CH4 to CH7.

The third access point AP3 intending to set the BSS3 may know that all the channels CH0 to CH7 are used by the other access points AP1 and AP2 through a scanning procedure. In this case, since the third access point AP3 does not have an empty channel, the BSS3 may be set to operate in a channel (eg, CH0 to CH3) that is being used by another access point. The fourth access point AP4 intending to configure the BSS4 may know that all the channels CH0 to CH7 are used by the other access points AP1, AP2, and AP3 through a scanning procedure. In this case, since the fourth access point AP4 does not have an empty channel, the BSS4 may be set to operate on a channel that is used by another access point (eg, CH4 to CH7).

At this time, the transmission and reception of the station belonging to the BSS1 may be interfered by the station belonging to the BSS3, and the transmission and reception of the station belonging to the BSS3 may be interfered with by the station belonging to the BSS1. In addition, transmission and reception of stations belonging to BSS2 may be interfered with by stations belonging to BSS4, and conversely, transmission and reception of stations belonging to BSS4 may be affected by stations belonging to BSS2.

In the above environment, the master access point may set the transmission interval of the first access point AP1 and the transmission interval of the third access point AP3 differently from CH0 to CH3. In addition, the master access point may set the transmission period of the second access point (AP2) and the transmission period of the fourth access point (AP4) differently from CH4 to CH7. Here, one of the access points AP1, AP2, AP3, AP4 may operate as a master access point, or another access point other than the access points AP1, AP2, AP3, AP4 may be a master access point. It can work as

On the other hand, an access point having a coordination function may inform that it operates as a master access point through a beacon frame or a probe response frame. When the access point that wants to set up a new BSS has found a master access point, the access point may request the master access point an optimal channel allocation considering the operating channels of other BSSs.

The master access point may perform coordination with respect to an operation channel and a transmission interval so as not to collide with another access point when the same channel is allocated to the access points or when a channel other than the primary channel is allocated to overlap. . The access point may allocate resources to terminals belonging to its BSS within the operation channel and transmission interval allocated by the master access point, and transmit and receive frames with the terminals through the allocated resources. The master access point may assign a transmission interval to each of the access points within a beacon interval.

If each of the access points is far enough apart from each other even when the same channel is used, the access points may transmit frames simultaneously. The master access point may obtain interference information for the neighboring access point from each of the access points, and allocate the same transmission interval to the access points that do not interfere with each other based on the obtained interference information.

To this end, the access point transmits a frame request frame specified in the IEEE 802.11 standard to a terminal connected to the terminal, and receives a frame response frame, which is a response to the frame request frame, from the terminal. And interference information about the terminal connected to the neighboring access point. In addition, the access point may obtain the interference information for the neighboring access point by using the beacon request frame / beacon response frame instead of the frame request frame / frame response frame. The access point may transmit the obtained interference information to the master access point. The master access point may perform coordination on the operation channel and the transmission interval based on the interference information obtained from the access point.

Alternatively, the terminal may transmit the interference information for at least one of the neighboring access point and the neighboring terminal to the access point connected thereto without exchanging a frame request frame / frame response frame (or a beacon request frame / beacon response frame). The access point may transmit the obtained interference information to the master access point. The master access point may perform coordination on the operation channel and the transmission interval based on the interference information obtained from the access point.

When the master access point exists in the WLAN, the channel may be efficiently used through coordination of the operation channel and the transmission interval. However, when the master access point does not exist, the channel may be wasted as follows.

6 is a conceptual diagram illustrating a channel wasted in the existing WLAN.

Referring to FIG. 6, the first access point AP1 may set BSS1 to operate at CH0 to CH3 (total 80 MHz), and set the primary channel to CH0. The second access point AP2 may set BSS2 to operate at CH1 to CH4 (80 MHz total), and set the primary channel to CH4.

The first access point AP1 may transmit / receive a frame with the terminals belonging to the BSS1 through CH0 to CH3 during T1, and may transmit / receive the frame with the terminals belonging to the BSS1 through CH0 to CH1 during T2. On the other hand, the UE belonging to the BSS2 to transmit the frame using the 80MHz bandwidth during T2 is far from the first access point (AP1) CH1 ~ CH4 may be in the idle state at the terminal side, in this case CH1 The RTS frame is transmitted using the 80 MHz bandwidth through ˜CH4, but the second access point AP2 clears the CTS frame because all of the CH1 to CH4 are not idle due to the transmission of the first access point AP1. Cannot be transmitted to the terminal. That is, when a terminal belonging to BSS2 supports dynamic RTS / CTS (clear to send) defined in the IEEE 802.11ac standard, the second access point (AP2) transmits the CTS frame through the CH2 to CH4 RTS frames during T2. May be transmitted to the terminal that has transmitted the CTS frame, but may not transmit the CTS frame to the terminal that has transmitted the RTS frame during T2 when it does not support dynamic RTS / CTS. Therefore, CH2 to CH4 may be wasted during T2.

If the master access point allocates CH0 to CH1 to the first access point AP1 and CH2 to CH4 to the second access point AP2 at T2, the corresponding channel assignment information is assigned to the first access point AP1, 2 If the access point AP2 and the terminal connected to the BSS1 and the BSS2 are notified, the access points AP1 and AP2 may simultaneously transmit and receive a frame at T2.

Allocating non-overlapping channels to BSSs as much as possible, but overlapping channels due to insufficient number of channels

FIG. 7 is a conceptual diagram illustrating an embodiment of a method of performing coordination on an overlapping channel. FIG.

Referring to FIG. 7, the first access point AP1 to set BSS1 may request channel allocation from the master access point. The master access point may allocate CH0 to CH3 (80 MHz in total) to the first access point AP1 and set CH0 as a primary channel of the first access point AP1. The second access point AP2 wishing to set the BSS2 may request channel allocation from the master access point. The master access point may allocate CH1 to CH4 (80 MHz in total) to the second access point AP2 and set CH4 as the primary channel of the second access point AP2. Here, the primary channels of each of the access points AP1 and AP2 may be arranged to be as far apart as possible. CH1 to CH3 may be allocated to both the first access point AP1 and the second access point AP2.

The master access point may perform coordination with respect to an operation channel and a transmission interval so that the first access point AP1 may transmit and receive a frame through CH0 to CH3 during T1. The master access point transmits and receives a frame through the CH0 to CH1 during T2, and the second access point AP2 transmits and receives a frame through CH3 through CH4 during T2. Coordination may be performed. In this case, the access points AP1 and AP2 may simultaneously transmit and receive frames through the narrow bands CH0 to CH1 and CH3 to CH4 during the same transmission period T2. The master access point may perform coordination with respect to an operation channel and a transmission interval so that the second access point AP2 may transmit and receive a frame through CH1 to CH4 during T3.

8 is a conceptual diagram illustrating a channel allocation method according to an embodiment of the present invention, and FIG. 9 is a conceptual diagram illustrating a channel allocation method according to another embodiment of the present invention.

8 and 9, a first access point AP1 to set BSS1 may request channel allocation from a master access point M-AP. The master access point (M-AP) may allocate a channel to the first access point AP1 in consideration of an operating channel of neighboring access points. For example, the master access point AP1 may allocate CH0 to CH3 (ie, FIG. 7) to the first access point AP1 and set CH0 as the primary channel of the first access point AP1. Can be.

 The second access point AP2 wishing to set the BSS2 may request channel allocation from the master access point M-AP. The master access point (M-AP) may allocate a channel to the second access point AP2 in consideration of the operating channel of the neighboring access points. For example, the master access point AP2 may allocate CH1 to CH4 (ie, FIG. 7) to the second access point AP2 and set CH4 as the primary channel of the second access point AP2. Can be.

Here, the primary channel of the master access point (M-AP) may be set differently from the primary channel of each of the access points AP1 and AP2. The master access point M-AP may support a wide band (eg, 160 MHz) to include an operating channel of the access points AP1 and AP2.

The master access point (M-AP) may perform coordination for an operation channel and a transmission interval of each of the access points AP1 and AP2 using a resource allocation frame or a beacon frame. The master access point (M-AP) may perform coordination for an operation channel and a transmission interval of each of the access points AP1 and AP2 in an interval unit of a resource allocation frame or an interval unit of a beacon frame. Here, the master access point (M-AP) allocates CH0 to CH3 to the first access point (AP1) during T1, allocates CH0 to CH1 to the first access point (AP1) during T2, and CH3 to CH4 during T2. Is allocated to the second access point AP2, and CH1 to CH4 are allocated to the second access point AP2 during T3.

Resource Allocation Frame Based Coordination

The master access point (M-AP) may periodically transmit the beacon frame 800 in a broadcast manner. The master access point (M-AP) may generate a resource allocation frame 801 for channel coordination with respect to the first access point AP1 after transmitting the beacon frame. The configuration of resource allocation elements included in the resource allocation frame 801 is as follows.

10 is a conceptual diagram illustrating an embodiment of a resource allocation element.

Referring to FIG. 10, a resource allocation element may include an allocated resource field, an allocation interval field, and an allocation period field. The allocated resource field may include a start time field, a duration field, and a bandwidth field. When one resource allocation element indicates a plurality of transmission intervals, a plurality of allocated resource fields may exist in one resource allocation element. For example, when one resource allocation element indicates two different transmission intervals, two allocated resource fields may exist in one resource allocation element.

 The start time field may have a size of 8 bits and may indicate a duration from a transmission time of a resource allocation frame (or beacon frame) to a start time of an allocated transmission interval. The duration field may have a size of 14 bits and may indicate a duration of an allocated transmission interval. The bandwidth field may have a size of 2 bits and may indicate available bandwidth for an allocated transmission interval. That is, the bandwidth field may indicate a usable bandwidth during the allocated transmission interval.

 The allocation interval field may have a size of 16 bits and may indicate a transmission interval of a resource allocation frame (or beacon frame). The allocation period field may have a size of 8 bits and may be expressed as a multiple of the allocation interval field. The allocation period field may indicate a section to which information included in an allocated resource field of a corresponding resource allocation frame (or beacon frame) is applied. Therefore, a new resource allocation frame (or beacon frame) may not be transmitted during the period indicated by the allocation period field.

In addition, the resource allocation element may further include a beacon interval, a target beacon transmission time (TBTT), a time stamp, and the like of the master access point (M-AP). Here, the beacon interval, TBTT, and time stamp of the master access point may be used for synchronization with the master access point (M-AP).

Referring back to FIGS. 8 and 9, the resource allocation element of the resource allocation frame 801 may include two allocated resource fields. The first allocated resource field may include a start time field indicating a duration from the transmission time of the resource allocation frame 801 to the start time of T1, a duration field indicating the duration of T1, and a bandwidth field indicating CH0 to CH3. . The second allocated resource field may include a start time field indicating a duration from a transmission time of the resource allocation frame 801 to a start time of T2, a duration field indicating a duration of T2, and a bandwidth field indicating CH0 to CH1. . In addition, the duration field included in the resource allocation frame 801 may be set from the transmission time of the resource allocation frame 801 to the completion of transmission of the resource allocation feedback frame 802 to ensure transmission of the resource allocation feedback frame 802. It can indicate duration.

The master access point (M-AP) may transmit the resource allocation frame 801 to the first access point AP1. In this case, the master access point (M-AP) may transmit the resource allocation frame 801 to the first access point AP1 through CH0, which is a primary channel of the first access point AP1. The first access point AP1 may receive the resource allocation frame 801 from the master access point M-AP, and based on the resource allocation element included in the received resource allocation frame 801, during the period CH1 to CH0 ~. You can see that CH3 is available and CH0 ~ CH1 are available during T2. In addition, the first access point AP1 may include an interval, a period, a beacon interval of a master access point (M-AP), a TBTT, a resource allocation frame 801 based on a resource allocation element included in the resource allocation frame 801. Know the time stamp and the like.

Thereafter, the first access point AP1 may generate a resource allocation feedback frame 802. The resource allocation feedback frame 802 may be used to inform the master access point (M-AP) of resource information required for transmission and reception over an interval according to the next resource allocation frame. The configuration of the resource allocation feedback frame 802 is as follows.

11 is a block diagram illustrating an embodiment of a resource allocation feedback frame.

Referring to FIG. 11, the resource allocation feedback frame includes a frame control field 1100, a duration field 1101, a receiver address field 1102, a transmitter address field 1103, and a feedback control field ( 1104, estimated UL duration field 1105, average UL data rate field 1106, estimated DL duration field 1107, average DL data rate field 1108, 20 MHz failure rate field 1109 ), A 40 MHz failure rate field 1110, an 80 MHz failure rate field 1111, a 160 MHz failure rate field 1112, and a frame check sequence (FCS) field 1113. In addition, the resource allocation feedback frame is the minimum bandwidth required for transmission and reception through the interval information according to the next resource allocation frame (or next beacon frame), bandwidth information used during the interval according to the previous resource allocation frame (or previous beacon frame). It may further include information.

Feedback control field 1104 includes bandwidth field 1104-1, UL feedback indication field 1104-2, DL feedback indication field 1104-3, 20 MHz indication field 1104-4, 40 MHz indication field. 1104-5, an 80 MHz indication field 1104-6, and a 160 MHz indication field 1104-7.

The bandwidth field 1104-1 may have a size of 2 bits. The bandwidth field 1104-1 indicates the minimum bandwidth required (20 MHz / 40 MHz / 80 MHz / 160 MHz, etc.) for the next interval. The 20 MHz indication field 1104-4, the 40 MHz indication field 1104-5, the 80 MHz indication field 1104-6, and the 160 MHz indication field 1104-7 each have a size of 1 bit, each 20 MHz during the previous transmission interval. , 40MHz, 80MHz, 160MHz whether the transmission was made. If this bit is set to '1', it means that the previous transmission has been performed with the corresponding bandwidth.

 The UL feedback indication field 1104-2 may have a size of 1 bit and may indicate whether an estimated UL duration field 1105 and an average UL data rate field 1106 exist in a resource allocation feedback frame. If this bit is 1 then there is an estimated UL duration field 1105 and an average UL data rate field 1106 within the resource allocation feedback frame, and if 0 this is an estimated UL duration field 1105 and average UL data within the resource allocation feedback frame There is no rate field 1106.

The DL feedback indication field 1104-3 may have a size of 1 bit and may indicate whether the estimated DL duration field 1107 and the average DL data rate field 1108 exist in the resource allocation feedback frame. If this bit is 1 then there is an estimated DL duration field 1107 and an average DL data rate field 1108 within the resource allocation feedback frame, and if 0 this is an estimated DL duration field 1107 and average DL data within the resource allocation feedback frame There is no rate field 1108.

If the 20 MHz indication field 1104-4 is 1, the 20 MHz failure rate field 1109 is present in the resource allocation feedback frame. If 0, the 20 MHz failure rate field 1109 is not present in the resource allocation feedback frame. If the 40 MHz indication field 1104-5 is 1, the 40 MHz failure rate field 1110 is present in the resource allocation feedback frame. If the 40 MHz indication field 1104-5 is 1, the 40 MHz failure rate field 1110 is not present in the resource allocation feedback frame. If the 80 MHz indication field 1104-6 is 1, the 80 MHz failure rate field 1111 is present in the resource allocation feedback frame. If 0, the 80 MHz failure rate field 1111 is not present in the resource allocation feedback frame. If the 160 MHz indication field 1104-7 is 1, the 160 MHz failure rate field 1112 is present in the resource allocation feedback frame. If 0, the 160 MHz failure rate field 1112 is not present in the resource allocation feedback frame.

The estimated UL duration field 1105 may have a size of two octets and may indicate an expected duration required for uplink transmission during an interval according to a next resource allocation frame (or beacon frame). The expected duration required for uplink transmission is the data size to be transmitted during the interval according to the next resource allocation frame (or beacon frame) and the average data rate of the uplink transmission during the interval according to the previous resource allocation frame (or beacon frame). It can be calculated based on. The average UL data rate field 1106 may have a size of two octets and may indicate an average data rate of uplink transmission during an interval according to a previous resource allocation frame (or beacon frame).

The estimated DL duration field 1107 may have a size of one octet and may indicate an expected duration required for downlink transmission during an interval according to the next resource allocation frame (or beacon frame). The expected duration required for downlink transmission is the data size to be transmitted during the interval according to the next resource allocation frame (or beacon frame) and the average data rate of the downlink transmission during the interval according to the previous resource allocation frame (or beacon frame). It can be calculated based on. The average DL data rate field 1108 may have a size of one octet and may indicate an average data rate of downlink transmission during an interval according to a previous resource allocation frame (or beacon frame).

The 20 MHz failure rate field 1109 may have a size of one octet and may indicate a failure rate of transmission through a 20 MHz bandwidth during an interval according to a previous resource allocation frame (or beacon frame). The 40 MHz failure rate field 1110 may have a size of one octet and may indicate a failure rate of transmission over a 40 MHz bandwidth during an interval according to a previous resource allocation frame (or beacon frame). The 80 MHz failure rate field 1111 may have a size of one octet and may indicate a failure rate of transmission over an 80 MHz bandwidth during an interval according to a previous resource allocation frame (or beacon frame). The 160 MHz failure rate field 1112 may have a size of one octet and may indicate a failure rate of transmission through a 160 MHz bandwidth during an interval according to a previous resource allocation frame (or beacon frame). Here, the transmission failure rate may be expressed as '(transmission failure count / transmission attempt count) × 255'.

8 and 9, the first access point AP1 may transmit the generated resource allocation feedback frame 802 to the master access point (M-AP). Alternatively, when the first access point AP1 receives an arbitrary poll frame from the master access point M-AP, the first access point AP1 transmits the generated resource allocation feedback frame 802 to the master access point M-AP. Can be. At this time, the first access point AP1 is a resource allocation feedback frame in a non-HT (duplicate) format through the entire operating channels CH0 to CH3 to protect transmission of the resource allocation feedback frame 802. 802 may be sent to a master access point (M-AP).

The master access point (M-AP) may receive a resource allocation feedback frame 802 from the first access point AP1, and the next resource allocation frame based on the information included in the received resource allocation feedback frame 802. Coordination may be performed according to the interval. For example, the master access point (M-AP) may include an expected duration required for uplink transmission included in the resource allocation feedback frame 802, an estimated duration required for downlink transmission, and an average data rate of uplink transmission. In consideration of the average data rate of downlink transmission, a resource may be allocated to the first access point AP1.

In addition, the master access point (M-AP) may allocate a bandwidth having a relatively low transmission failure rate to the first access point AP1 during the interval according to the next resource allocation frame in consideration of the transmission failure rate according to the bandwidth. For example, if the transmission failure rate of 40 MHz bandwidth or less is lower than the 80 MHz bandwidth during the interval according to the previous resource allocation frame, the master access point (M-AP) may access the first access below 40 MHz bandwidth during the interval according to the next resource allocation frame. Can be assigned to the point AP1.

When the master access point (M-AP) completes reception of the resource allocation feedback frame 802, the master access point (M-AP) may generate a resource allocation frame 803 for coordination with respect to an operation channel and a transmission interval of the second access point AP2. have. The resource allocation element included in the resource allocation frame 803 may be the same as the resource allocation element described with reference to FIG. 10.

That is, the resource allocation element of the resource allocation frame 803 may include two allocated resource fields. The first allocated resource field may include a start time field indicating a duration from the transmission time of the resource allocation frame 803 to the start time of T2, a duration field indicating the duration of T2, and a bandwidth field indicating CH3 to CH4. . The second allocated resource field may include a start time field indicating a duration from the transmission time of the resource allocation frame 803 to the start time of T3, a duration field indicating the duration of T3, and a bandwidth field indicating CH1 to CH4. . In addition, the duration field included in the resource allocation frame 803 may include the time period from the transmission time of the resource allocation frame 803 to the transmission completion time of the resource allocation feedback frame 804 in order to ensure transmission of the resource allocation feedback frame 804. It can indicate duration.

The master access point (M-AP) may transmit the resource allocation frame 803 to the second access point AP2. In this case, the master access point (M-AP) may transmit the resource allocation frame 803 to the second access point AP2 through CH4, which is a primary channel of the second access point AP2. The second access point AP2 may receive the resource allocation frame 803 from the master access point M-AP and, based on the resource allocation element included in the received resource allocation frame 803, CH3 ˜2 during the T2. You can see that CH4 is available and CH1 ~ CH4 are available during T3. In addition, the second access point AP2 may be based on a resource allocation element included in the resource allocation frame 803, an interval of a resource allocation frame 803, a period, a beacon interval of a master access point (M-AP), TBTT, Know the time stamp and the like.

Thereafter, the second access point AP2 may generate a resource allocation feedback frame 804. The resource allocation feedback frame 804 may be used to inform the master access point (M-AP) of resource information required during the interval according to the next resource allocation frame. The resource allocation feedback frame 804 may be the same as the resource allocation feedback frame described above with reference to FIG. 11.

The second access point AP2 may transmit the generated resource allocation feedback frame 804 to the master access point M-AP. Alternatively, when the second access point AP2 receives any poll frame from the master access point M-AP, the second access point AP2 may transmit the generated resource allocation feedback frame 804 to the master access point M-AP. In this case, the second access point AP2 masters the resource allocation feedback frame 804 in a non-HT duplicate form through the entire operating channels CH1 to CH4 to protect transmission of the resource allocation feedback frame 804. (M-AP) can be sent.

The master access point (M-AP) may receive a resource allocation feedback frame 804 from the second access point AP2, and the next resource allocation frame based on the information included in the received resource allocation feedback frame 804. Coordination may be performed according to the interval. For example, the master access point (M-AP) may include an expected duration required for uplink transmission included in the resource allocation feedback frame 804, an estimated duration required for downlink transmission, and an average data rate of uplink transmission. In consideration of the average data rate of downlink transmission, a resource may be allocated to the second access point AP2.

In addition, the master access point (M-AP) may allocate a bandwidth having a relatively low transmission failure rate to the second access point AP2 during the interval according to the next resource allocation frame in consideration of the transmission failure rate according to the bandwidth. For example, if the transmission failure rate of 40 MHz bandwidth or less is lower than the 80 MHz bandwidth during the interval according to the previous resource allocation frame, the master access point (M-AP) may access the second access below 40 MHz bandwidth during the interval according to the next resource allocation frame. Can be assigned to the point AP2.

Beacon frame-based coordination

The master access point (M-AP) is a first resource allocation element for channel coordination for the operating channel and the transmission interval of the first access point (AP), the operating channel and the channel for the transmission interval of the second access point (AP) A beacon frame 800 including a second resource allocation element for coordination may be generated. Each of the resource allocation elements may be the same as the resource allocation element described above with reference to FIG. 10. Here, when the resource allocation element indicates a plurality of transmission intervals, a plurality of allocated resource fields may exist in one resource allocation element.

The first resource allocation element may include two allocated resource fields. The first allocated resource field may include a start time field indicating a duration from the transmission time of the beacon frame 800 to the start time of T1, a duration field indicating the duration of T1, and a bandwidth field indicating CH0 to CH3. The second allocated resource field may include a start time field indicating a duration from the transmission time of the beacon frame 800 to the start time of T2, a duration field indicating the duration of T2, and a bandwidth field indicating CH0 to CH1. In addition, the first resource allocation element may further include a basic service set identifier (BSSID) of the first access point AP1.

The second resource allocation element may include two allocated resource fields. The first allocated resource field may include a start time field indicating a duration from the transmission time of the beacon frame 800 to the start time of T2, a duration field indicating the duration of T2, and a bandwidth field indicating CH3 to CH4. The second allocated resource field may include a start time field indicating a duration from the transmission time of the beacon frame 800 to the start time of T3, a duration field indicating the duration of T3, and a bandwidth field indicating CH1 to CH4. In addition, the second resource allocation element may further include the BSSID of the second access point AP2.

Meanwhile, the master access point (M-AP) may set a restricted access window (RAW) for each of the resource allocation feedback frames 802 and 804 to ensure transmission of the resource allocation feedback frames 802 and 804. The beacon frame 800 including the set RAW information may be generated. Alternatively, the master access point (M-AP) may ensure transmission of resource allocation feedback frames 802, 804 using the duration field of the beacon frame 800. That is, the duration field of the beacon frame 800 is a transmission completion time of the resource allocation feedback frames 802, 804 from the transmission time of the beacon frame 800 to ensure the transmission of the resource allocation feedback frames (802, 804) It can represent the duration up to.

The master access point (M-AP) may transmit the beacon frame 800 in a broadcast manner. In this case, the master access point (M-AP) may transmit the beacon frame 800 in a non-HT duplicate form through CH0 to CH4 which are the entire operating channels of the master access point (M-AP).

The first access point AP1 may receive the beacon frame 800 from the master access point M-AP, and CH0 to CH3 are generated during T1 based on the first resource allocation element included in the beacon frame 800. You can see that it is available and CH0 ~ CH1 are available during T2. Thereafter, the first access point AP1 may generate a resource allocation feedback frame 802. The resource allocation feedback frame 802 may be used to inform the master access point (M-AP) of resource information required during the interval according to the next resource allocation frame. The resource allocation feedback frame 802 may be the same as the resource allocation feedback frame described above with reference to FIG. 11.

The first access point AP1 may transmit the generated resource allocation feedback frame 802 to the master access point (M-AP). Alternatively, when the first access point AP1 receives an arbitrary poll frame from the master access point M-AP, the first access point AP1 may transmit the generated resource allocation feedback frame 802 to the master access point M-AP. In this case, the first access point AP1 masters the resource allocation feedback frame 802 in a non-HT duplicate form through the entire operating channels CH0 to CH3 to protect transmission of the resource allocation feedback frame 802. (M-AP) can be sent.

The master access point (M-AP) may receive a resource allocation feedback frame 802 from the first access point AP1, and may transmit to the next beacon frame based on the information included in the received resource allocation feedback frame 802. The coordination of the intervals can be performed.

Meanwhile, the second access point AP2 may receive the beacon frame 800 from the master access point M-AP, and during T2 based on the second resource allocation element included in the beacon frame 800. It can be seen that CH3 ~ CH4 are available and CH1 ~ CH4 are available during T3. Thereafter, the second access point AP2 may generate a resource allocation feedback frame 804. The resource allocation feedback frame 804 may be used to inform the master access point (M-AP) of resource information required during the interval according to the next resource allocation frame. The resource allocation feedback frame 804 may be the same as the resource allocation feedback frame described above with reference to FIG. 11.

The second access point AP2 may transmit the generated resource allocation feedback frame 804 to the master access point M-AP. Alternatively, when the second access point AP2 receives any poll frame from the master access point M-AP, the second access point AP2 may transmit the generated resource allocation feedback frame 804 to the master access point M-AP. In this case, the second access point AP2 masters the resource allocation feedback frame 804 in a non-HT duplicate form through the entire operating channels CH1 to CH4 to protect transmission of the resource allocation feedback frame 804. (M-AP) can be sent.

The master access point (M-AP) may receive the resource allocation feedback frame 804 from the second access point (AP2), and transmits to the next beacon frame based on the information included in the received resource allocation feedback frame 804. The coordination of the intervals can be performed.

Meanwhile, when the master access point (M-AP) and the access points AP1 and AP2 have a hidden access point relationship, the resource allocation element and the resource allocation feedback frame may be transmitted and received via a wire.

Next, a frame transmission and reception procedure of each of the access points AP1 and AP2 will be described. The frame transmission and reception procedure is the same in both the resource allocation frame-based coordination scheme and the beacon frame-based coordination scheme, and thus will be described collectively.

The first access point AP1 may transmit and receive a frame with terminals belonging to the BSS1 using CH0 to CH4 at T1. That is, the first access point AP1 may notify that data for at least one terminal belonging to the BSS1 is buffered by transmitting the beacon frame 805. In addition, the beacon frame 805 may include DL RAW information for transmission of the downlink data frames 808, 809, 811, 812 and UL RAW information for transmission of the uplink data frames 810, 813. Can be. That is, transmission and reception of downlink data frames 808, 809, 811, and 812 may be performed in DL RAW, and transmission and reception of uplink data frames 810, 813 may be performed in UL RAW.

 The first access point AP1 may receive power save (POLL) -Poll frames 806 and 807 from terminals belonging to the BSS1 and the terminals are awake through the PS-Poll frames 806 and 807. After confirming, the downlink data frames 808 and 809 may be transmitted. In addition, the first access point AP1 may receive an uplink data frame 810 from a terminal belonging to the BSS1. Thereafter, the first access point AP1 may transmit / receive a frame with terminals belonging to the BSS1 using CH0 to CH1 at T2. That is, the first access point AP1 may transmit the downlink data frames 811 and 812 to the terminals belonging to the BSS1 and may receive the uplink frame 813 from the terminal belonging to the BSS1.

Meanwhile, the second access point AP2 may transmit and receive a frame with terminals belonging to the BSS2 using CH3 to CH4 in T2. That is, the second access point AP2 may inform that the data for at least one terminal belonging to the BSS2 is buffered by transmitting the beacon frame 814. Also, the beacon frame 814 may include DL RAW information for transmission of the downlink data frames 817, 818, 819, and 820 and UL RAW information for transmission of the uplink data frame 821. That is, transmission and reception of downlink data frames 817, 818, 819, and 820 may be performed in DL RAW, and transmission and reception of uplink data frame 821 may be performed in UL RAW.

The second access point AP2 may receive the PS-Poll frames 815 and 816 from terminals belonging to the BSS2, and after confirming that the terminals are awake through the PS-Poll frames 815 and 816, Link data frames 817 and 818 may be transmitted. That is, the second access point AP2 may perform simultaneous transmission with the first access point AP1 through the narrow band during T2.

Thereafter, the second access point AP2 may transmit / receive a frame with UEs belonging to the BSS2 using CH1 to CH4 in T3. That is, the second access point AP2 may transmit the downlink data frames 819 and 820 to the terminals belonging to the BSS2 and may receive the uplink frame 821 from the terminal belonging to the BSS2.

Embodiments of the present invention may be embodied in the form of program instructions that may be executed by various computer means and may be recorded in a computer readable medium. Computer-readable media may include, alone or in combination with the program instructions, data files, data structures, and the like. The program instructions recorded on the computer readable medium may be those specially designed and constructed for the embodiments of the present invention, or may be known and available to those skilled in computer software.

A computer readable medium may refer to a hardware device that is specifically configured to store and execute program instructions, such as a ROM, a RAM, a flash memory, and the like. Hardware devices may be configured to operate with at least one software module to perform operations in accordance with embodiments of the present invention, and vice versa. The program command may mean a high-level language code that can be executed in a computer based on an interpreter as well as machine code generated by a compiler.

Although described with reference to the above embodiments, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention described in the claims below. Could be.

Claims (20)

A channel setting method performed in a first access point,
Receiving a first frame comprising scheduling information for a first interval from a second access point;
Generating a second frame including resource related information required for transmission and reception through a second interval subsequent to the first interval; And
Transmitting the second frame to the second access point,
The scheduling information indicates radio resources used for communication of the first access point within the first interval, and the resource related information is radio required for communication of the first access point within the second interval. A method of channel establishment, indicating resources. The method according to claim 1,
And the first frame is a beacon frame. The method according to claim 1,
The first frame includes duration information indicating a transmission start time of the first frame to the transmission end time of the second frame. The method according to claim 1,
And the first frame includes limited access window information indicating a transmission interval of the second frame. The method according to claim 1,
And the first frame is received at the start of the first interval. The method according to claim 1,
The scheduling information,
And indicating at least one of an operating channel and a transmission interval of the first access point during the first interval. The method according to claim 1,
The resource related information,
At least one of expected duration information required for transmitting / receiving a frame through the second interval, a data rate at the first pre-interval, and a transmission failure rate for each bandwidth at the pre-first interval; How to set up. The method according to claim 1,
Transmitting the second frame to the second access point,
Transmitting the second frame to the second access point when a poll frame is received from the second access point. The method according to claim 1,
The channel setting method,
And transmitting and receiving a frame with at least one terminal connected to the first access point within an operating channel and a transmission interval indicated by the scheduling information. A channel management method performed at a second access point,
Generating a first frame including scheduling information for a first interval;
Transmitting the first frame to a first access point; And
Receiving a second frame from the first access point, the second frame including resource related information required for transmission / reception over a second interval subsequent to the first interval,
The scheduling information indicates radio resources used for communication of the first access point within the first interval, and the resource related information is radio required for communication of the first access point within the second interval. A channel management method that directs resources. The method according to claim 10,
And the first frame is a resource allocation frame. The method according to claim 10,
The first frame,
And a beacon frame of the second access point is transmitted to the first access point. The method according to claim 10,
The scheduling information,
And indicating at least one of an operating channel and a transmission interval of the first access point during the first interval. The method according to claim 10,
The resource related information,
At least one of expected duration information required for transmitting / receiving a frame through the second interval, a data rate at the first pre-interval, and a transmission failure rate for each bandwidth at the pre-first interval; How to manage. The method according to claim 10,
The channel management method,
Generating scheduling information for the second interval based on the resource related information. As the first access point,
A processor; And
At least one instruction executed by the processor includes a memory (memory),
The at least one command is
Receiving a first frame comprising scheduling information for a first interval from a second access point;
Generating a second frame including resource related information required for transmission and reception through a second interval subsequent to the first interval; And
Perform the step of transmitting the second frame to the second access point,
The scheduling information indicates radio resources used for communication of the first access point within the first interval, and the resource related information is radio required for communication of the first access point within the second interval. A first access point indicating resources. The method according to claim 16,
The scheduling information,
And at least one of an operating channel and a transmission interval of the first access point during the first interval. The method according to claim 16,
The resource related information,
At least one of expected duration information required for frame transmission and reception through the second interval, a data rate at the first pre-interval, and a transmission failure rate for each bandwidth at the first pre-interval; 1 access point. The method according to claim 16,
Transmitting the second frame to the second access point,
Transmitting the second frame to the second access point when a resource allocation frame is received from the second access point. The method according to claim 16,
The at least one command is
And transmitting and receiving a frame with at least one terminal connected to the first access point within an operating channel and a transmission interval indicated by the scheduling information.

Images