WO2012011725A2 - Method and device for identifying movement channel information in a wireless network - Google Patents

Abstract

According to an embodiment of the present invention, the method for identifying the channel information of an enabling STA comprises: a step of receiving an enablement request frame from at least one dependent STA; a step of approving the enablement request by transmitting an enablement response frame which corresponds to the received enablement request frame; a step of transmitting a 1^st frame, requesting information about the movement channel of the at least one dependent STA, to the at least one dependent STA; and a step of receiving a 2^nd frame which corresponds to the 1^st frame and identifying the movement channel information of the at least one dependent STA by using the 2^nd frame.

Description

Method and apparatus for identifying operating channel information in wireless network

The present invention relates to a wireless network using a TV white space, and more particularly to a method and apparatus for identifying operating channel information in a wireless network.

Currently, the television broadcasting service is moving from analog broadcasting to digital broadcasting. This is because digital broadcasting can provide high quality video and two-way services and use spectrum more efficiently.

This shift to digital broadcasting provides an idle frequency band that can be used by any of the VHF (Very High Frequency, 54 MHz to 88 MHz) band and the UHF (Ultra High Frequency, 174 MHz to 698 MHz) band allocated for the conventional analog broadcasting. An example of such an idle frequency band is a TV white space (hereinafter referred to as TVWS).

That is, TVWS means an empty frequency band not used by broadcasters in the VHF and UHF frequency bands distributed for TV broadcasting, and is an unlicensed frequency band that anyone can use if the conditions for government radio regulation are satisfied. If a licensed device is not in use in this unlicensed frequency band, it is possible for an unlicensed device to use the band. Here, the licensed device refers to a user who is authorized to use the TV white space band and may also be referred to as a primary user or an incumbent user. .

Meanwhile, the Federal Communications Commission (FCC) has approved the frequencies of the VHF and UHF bands used by DTV as unlicensed bands that anyone can use if they meet regulatory requirements set by the FCC.

For example, as shown in FIG. 1, the FCC has determined that no authorized device such as a TV signal, a wireless microphone signal, or the like exists in the remaining TV channels except for channel 37 (a reserved channel for radio astronomy). In addition, regulations are underway to allow unlicensed devices to use the TV channels. In accordance with the US FCC's policy, other countries are developing corresponding policies and regulations on TV white space.

In addition, various wireless communication systems are being developed for using the TVWS, and the IEEE (Institute of Electrical and Electronics Engineers) 802.11 Working Group uses a wireless local area network (WLAN) system using TVWS as an 802.11af standard. The development is in progress.

The present invention provides a newly defined information element for identifying information on an operation channel of a dependent STA.

The present invention also provides a method and apparatus for enabling an enabling STA operating in a TVWS to identify information on an operating channel of a dependent STA.

The present invention includes the steps of receiving an enablement request frame from at least one Dependent STA; Approving an enablement request by transmitting an enablement response frame corresponding to the received enablement request frame; Transmitting a first frame for requesting information on an operation channel of the at least one dependent STA to the at least one dependent STA; And receiving a second frame corresponding to the first frame, and identifying operating channel information of the at least one dependent STA by using the second frame.

In addition, the present invention receives an enablement request frame from at least one Dependent STA and transmits an enablement response frame corresponding to the received enablement request frame, for the operation channel of the at least one Dependent STA An RF transceiver for transmitting a first frame requesting information to the at least one Dependent STA and receiving a second frame corresponding to the first frame; And a control unit for identifying operating channel information of the at least one dependent STA using the second frame received from the at least one dependent STA.

According to an embodiment of the present invention, the Enabling STA among the wireless LAN devices operating in the TVWS receives the information on the channel being used by the Dependent STA from the available channel list approved by the Dependent STA for channel management. To make it efficient.

On the other hand various other effects will be disclosed directly or implicitly in the detailed description of the embodiments of the present invention to be described later.

1 is a channel map showing a US TV band and a band in which a W-LAN device can operate;

2 illustrates two methods of defining a channel in a WLAN system using TVWS;

3 is a view showing an example of the maximum transmit power limited by the presence and type of the primary user existing in the adjacent channel in TVWS;

4 is a diagram illustrating an example of whether a TV signal of a neighboring channel varies according to a channel definition method of a wireless LAN system and a maximum transmission power according thereto;

5 illustrates an example of a procedure in which an Enabling STA approves an enablement to Dependent AP and Dependent STAs;

6 illustrates an example of a procedure in which an Enabling STA operating in TVWS approves an enablement to Dependent STAs;

FIG. 7 is a diagram illustrating an example of a procedure in which Dependent AP and Dependent STAs of FIG. 5 feed back information on an operation channel;

FIG. 8 is a diagram illustrating an example of a procedure in which Dependent STAs of FIG. 6 feed back information on an operation channel; FIG.

9 illustrates a structure of a DSE status query / response element according to an embodiment of the present invention;

10 illustrates a structure of a DSE status query / response element according to another embodiment of the present invention;

11 is a flowchart of a procedure in which an Enabling STA is fed back information on an operating channel of a Dependent STA using a DSE status query / response element;

12 is a block diagram illustrating a structure of wireless LAN devices in which an embodiment of the present invention can be implemented.

In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

The WLAN system performs communication using a channel bandwidth of 5 MHz, 10 MHz, 20 MHz, or 40 MHz in a 2.4 GHz band or a 5 GHz band. In contrast, the channel bandwidth of the TVWS is different according to regions and / or countries, and 6 MHz, 7 MHz, or 8 MHz may be used according to the corresponding region. As described above, since the channel allocation unit in the WLAN system and the channel allocation unit in the TVWS are different from each other, it is necessary to define a corresponding channel according to the channel bandwidth of the TVWS in the WLAN system using the TVWS.

For example, FIG. 2 illustrates two methods of defining corresponding channels (5 MHz, 10 MHz, 20 MHz, and 40 MHz) of a WLAN system in a TVWS band in which channels are allocated in units of 6 MHz.

Referring to (a) of FIG. 2, the first channel definition method (Channelization A) corresponds to a TV channel (center frequency) of each channel (5/10/20 / 40MHz) of the WLAN system. 6MHz) to be located at the center frequency.

Referring to (b) of FIG. 2, the second channel definition method (Channelization B) is performed by continuously performing the center frequency of the channel for each channel (5/10/20 / 40MHz) of the WLAN system. It is to be located at the boundary of the TV channel bands.

The WLAN system using the TVWS may perform communication using any one of the two channel definition methods described above.

Meanwhile, according to the US FCC regulation, in a wireless network using TVWS, when there is no TV signal (or TV broadcast) in an adjacent channel of an operation channel, the wireless LAN devices belonging to the network have a maximum of 100 Hz. It defines that it can operate with transmit power. In contrast, when there is a TV signal in the adjacent channel, it is defined that the wireless LAN devices belonging to the network can operate at a maximum transmit power of 40 kHz.

This limits the maximum transmission power of the WLAN devices in order to prevent interference with the primary user when a primary user (or a TV signal) exists in the adjacent channel.

For example, FIG. 3 shows an example of the maximum transmit power limited by the presence and the type of the primary user existing in the adjacent channel in the TVWS.

Referring to FIG. 3, when the operation channel is channel 22, since the primary user does not exist in channels 21 and 23, which are adjacent channels of the corresponding channel, the WLAN devices operating in the channel 22 are 100 The signal can be sent at a maximum transmit power of ㎽.

On the other hand, if the operating channel is channel 21 or channel 23, since the primary user, that is, the 'TV signal' exists in the adjacent channel of the channel, the wireless LAN devices operating in the channel 21 or 23 The maximum transmit power is limited to 40 kW.

In addition, when the operation channel is channel 40, the primary user exists in channels 39 and 41 which are adjacent channels of the channel. However, when the type of the primary user is a 'wireless microphone (W-MIC) signal' rather than 'TV signal', the wireless LAN devices may transmit a signal at a maximum transmit power of 100 Hz instead of 40 Hz. .

Meanwhile, although FIG. 3 illustrates that the wireless microphone signal is allocated to channel 39 and channel 41, the present invention is not limited thereto. That is, according to the change of FCC regulations, the wireless microphone signal may be changed to a channel number other than the 39 and 41 channels. In addition, although the wireless LAN devices operate at a maximum transmit power of 100 kHz or 40 kHz, depending on whether a TV signal exists in an adjacent channel, this may also be changed to another value according to the change of the FCC regulations. Can be.

4 illustrates an example of whether a TV signal exists in a neighboring channel that varies according to a channel definition of a WLAN system and a maximum transmission power according thereto. That is, in FIG. 4A, the WLAN system defines the corresponding channel using the first channel definition method of FIG. 2, and FIG. 4B corresponds to the second channel definition method of FIG. 2. You are defining a channel.

Referring to FIGS. 4A and 4B, TV signals exist in channels 27 and 33, and channels 28 through 32 are empty. In this state, the WLAN system needs to define a channel of 5 MHz, 10 MHz, 20 MHz or 40 MHz in order to use an empty TVWS channel.

First, when the WLAN system defines a channel of 5 MHz or 10 MHz, regardless of the channel definition method described above, it can be confirmed that the TV signal does not exist in the adjacent channel of the corresponding channel. Therefore, the WLAN system operating on channel k using the channel bandwidth of 5 MHz or 10 MHz may transmit a signal with a maximum transmit power of 100 kHz.

Next, when the WLAN system defines a channel of 20 MHz, regardless of the channel definition method described above, it can be confirmed that the TV signal exists in the adjacent channel of the corresponding channel. Therefore, the wireless LAN system operating on channel k using the channel bandwidth of 20 MHz is limited to a maximum transmit power of 40 kW.

That is, as shown in FIG. 4, even if a channel of the WLAN system shares the TVWS band, a TV signal may or may not exist in an adjacent channel according to the channel bandwidth of the corresponding channel. . Then, the maximum power that can be transmitted in the channel varies depending on whether the TV signal exists in the adjacent channel.

 Meanwhile, according to the FCC regulations, among WLAN devices operating in TVWS, a WLAN device that has access to a geo-location database may enable other devices to configure a network. It is prescribed.

When using the dynamic network configuration (Dynamic Station Enablement, or `` DSE '') specified in the FCC regulations and IEEE 802.11y, a wireless LAN device capable of accessing a geographical location database is an enabling station. The Enabling STA may grant an enablement for a channel available to a dependent station (hereinafter, referred to as a “Dependent STA”).

In this case, the Enabling STA may enable a plurality of TVWS channels to the Dependent STAs based on an available channel list obtained from the geographical location database. However, a channel on which an enablement approval procedure is performed by the enabling STA and a channel on which a dependent STA is later operated may be different from each other. Accordingly, the Enabling STA needs to receive feedback on information on a channel used by the Dependent STA among available channel lists approved by the Dependent STA.

However, in IEEE 802.11y and IEEE 802.11af, the Dependent STA does not provide a method for feeding back information on an operation channel. Therefore, according to an embodiment of the present invention, the Enabling STA among the WLAN devices operating in the TVWS may identify information on a channel used by the Dependent STA from the list of available channels approved by the Dependent STA. Provide a method.

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

5 shows an example of a procedure in which an Enabling STA approves an enablement to Dependent AP and Dependent STAs. In the present embodiment, it is assumed that the Enabling STA and the Dependent AP operate in the non-IEEE 802.11 network, and the Dependent AP and the Dependent STA operate in the IEEE 802.11 network. At this time, the Dependent AP serves as a proxy for relaying different networks using a generic advertisement service (GAS) frame.

Referring to FIG. 5, a WLAN device that may access a geo-location DB may become an Enabling STA 510 to perform an enablement procedure.

In this case, since the Enabling STA 510 includes its own location information, the Enabling STA 510 may access a geographical location database and obtain a list of available channels at the corresponding location. Hereinafter, in the present embodiment, it will be described on the assumption that the available channel list is channel 21, channel 22, and channel 23.

First, the procedure of enabling the enabling STA 510 to the dependent AP 520 will be described.

The dependent AP 520 transmits an enablement request frame 501 to the enabling STA 510. Then, the Enabling STA 510 transmits the enablement response frame 503 corresponding to the enablement request frame 501 to the Dependent AP 520.

The Enabling STA 510 defines an Enablement ID to distinguish the Dependent AP 520 from other Dependent STAs, and determines an available channel list to be granted to the Dependent AP 520. Accordingly, the Enabling STA 510 accepts the enablement request by transmitting an enablement response frame 503 including the enablement identifier information and the available channel information.

The dependent AP 520 selects one of TVWS channels approved by the Enabling STA 510 to perform a wireless network operation.

The enablement request frame 501 transmitted by the dependent AP 520 and the enablement response frame 503 transmitted by the enabling STA 510 include a generic advertisement service (GAS) frame defined in IEEE 802.11u. Can be used. In this case, the GAS frame may include information elements of a DSE enablement frame defined in IEEE 802.11y.

Meanwhile, in the present embodiment, the Enabling STA 510 assigns an enablement identifier 1 to the Dependent AP 520 and authorizes the Dependent AP 520 to operate in channels 21, 22, and 23. Assume

Next, the procedure of the Enabling STA 510 approving the enablement to the Dependent STAs 530 and 540 will be described. In this case, the Dependent AP 520 may serve as a proxy of the Dependent STAs 530 and 540 in the enablement approval procedure. That is, when the Enabling STA 510 and the Dependent STAs 530 and 540 operate in different networks, the Dependent AP 520 may repeat the relay between the Enabling STA 510 and the Dependent STAs 530 and 540. As a surrogate performs the function of performing communication.

Each of the first and second dependent STAs 530 and 540 transmits an enablement request frame 505 and 513 to the dependent AP 520. Then, the Dependent AP 520 Enabling the enablement request proxy frame (507, 515) to transmit the enablement request by the first and second Dependent STA (530, 540) STA (510) Will be sent to).

The Enabling STA 510 transmits an Enablement Response frame 509 and 517 corresponding to the enablement request proxy frames 507 and 515 to the Dependent AP 520. Then, the dependent AP 520 transmits the enablement response frames 511 and 519 to the first and second dependent STAs 530 and 540 to deliver the enablement response by the enabling STA 510. .

That is, the Enabling STA 510 allocates different enablement IDs to distinguish the first Dependent STA 530 and the second Dependent STA 540, and assigns them to the Dependent STAs 530 and 540. Determine the list of available channels to approve.

Subsequently, the Enabling STA 510 or the Dependent AP 520 receives the enablement response frames 509, 511, 517, and 519 including the enablement identifier information and the available channel information. 540 to approve the enablement request.

The first and second dependent STAs 530 and 540 select one of TVWS channels approved by the Enabling STA 510 to perform a wireless network operation. In this case, the first and second dependent STAs 530 and 540 do not need to know the existence and identifier (ID) of the Enabling STA 510, and recognize the Dependent AP 520 as an Enabling STA.

The enablement request proxy frames 507 and 515 transmitted by the Dependent AP 520 and the enablement response frames 509 and 517 transmitted by the Enabling STA 510 include a GAS frame defined in IEEE 802.11u. Can be used. In this case, the GAS frame is a frame defined to support an interworking service between an IEEE 802.11 network and an external network (or a non-IEEE 802.11 network).

In addition, the enablement request frames 505 and 513 transmitted by the first and second Dependent STAs 530 and 540 and the enablement response frames 511 and 519 transmitted by the dependent AP 520 are IEEE. DSE frames defined in 802.11y may be used. In this case, the DSE frame is a frame defined to support the enablement of the dynamic station in the IEEE 802.11 network.

Meanwhile, in the present embodiment, the Enabling STA 510 allocates an enablement identifier 2 to the first Dependent STA 530, and assigns an enablement identifier 3 to the second Dependent STA 540. 2, it is assumed that the 2 Dependent STAs 530 and 540 are allowed to operate on channels 21 and 23.

If the above enablement procedure is successfully performed, the Dependent AP 520 and the Dependent STAs 530 and 540 select one of the available channel lists approved by the Enabling STA 510 to perform wireless network operation. It can be done.

6 shows an example of a procedure in which an Enabling STA operating in TVWS approves an enablement to Dependent STAs. That is, unlike FIG. 5 described above, FIG. 6 illustrates a procedure for approving the enablement in an environment in which there is no Dependent AP serving as a proxy.

Referring to FIG. 6, a WLAN device that may access a geo-location DB may become an Enabling STA 610 to perform an enablement procedure.

Since the Enabling STA 610 includes its own location information, the Enabling STA 610 can access the geographical location database to obtain a list of available channels at the corresponding location. Hereinafter, in the present embodiment, it is assumed that the available channel list is channel 21, channel 22, and channel 23.

The first and second dependent STAs 620 and 630 transmit the enablement request frames 601 and 605 to the enabling STA 610.

Then, the Enabling STA 610 transmits an Enablement Response frame (603, 607) corresponding to the enablement request frame (601, 605) to the first and second Dependent STA (620, 630). Done.

In this case, the Enabling STA 610 transmits an enablement response frame 603 or 607 including an enablement identifier and available channel information to approve the enablement request.

The first and second dependent STAs 620 and 630 select one of TVWS channels approved by the Enabling STA 610 to start an operation.

The enablement request frames 601 and 605 transmitted by the first and second Dependent STAs 620 and 630 and the enablement response frames 603 and 607 transmitted by the Enabling STA 610 are IEEE 802.11. The DSE frame defined in y may be used.

Meanwhile, in the present embodiment, it is assumed that the Enabling STA 610 assigns the enablement identifier 1 to the first Dependent STA 620 so that the Enabling STA 610 may operate in the channels 21, 22, and 23. In addition, it is assumed that the Enabling STA 610 assigns the enablement identifier 2 to the second Dependent STA 630 to allow operation on the channels 21 and 23.

If the above-described enablement procedure is successfully performed, the Dependent STAs 620 and 630 may perform a wireless network operation using at least one channel among available channel lists approved by the Enabling STA 610.

FIG. 7 illustrates an example of a procedure in which the Dependent AP and the Dependent STAs of FIG. 5 feed back information on an operation channel.

Referring to FIG. 7, it is assumed that the dependent AP 520 performs a wireless network operation by using channel 21 of the available channel list approved by the enabling STA 510.

In addition, it is assumed that the first Dependent STA 530 communicates with the Dependent AP 520 using channel 21, and uses the second Dependent STA 540 with channel 23 and performs communication. . In addition, it is assumed that the second Dependent STA 540 communicates with the Dependent AP 520 using channel 21, and the second Dependent STA 540 uses channel 23 with the first Dependent STA 530. .

When the Enabling STA 510 queries the Dependent AP 520 and the Dependent STAs 530 and 540 for information on the operating channel, the Dependent AP 520 and the Dependent STAs 530 and 540 may be configured to query the information on the operating channel. Feedback to the query will be fed back.

First, the procedure of receiving the feedback on the operating channel from the dependent AP 520 by the enabling STA 510 will be described.

The Enabling STA 510 transmits a DSE Status Query Frame 701 to the Dependent AP 520. In this case, the DSE status query frame 701 includes an enablement identifier (Enablement ID = 1) assigned by the Enabling STA 510 to the Dependent AP 520 when the enablement is approved.

The dependent AP 520 identifies the enablement identifier included in the DSE status query frame 701. If the enablement identifier is an enablement identifier assigned thereto, the dependent AP 520 may determine a DSE status response frame 703 corresponding to the DSE status query frame 701. To the Enabling STA 510.

In this case, the DSE status response frame 703 includes information about a channel on which the Dependent AP 520 operates, that is, channel 21. In addition, the DSE status response frame 703 may include information on the operation class of the operation channel and information on the maximum power that can be transmitted in the operation channel.

The Enabling STA 510 may identify channel information operated by the Dependent AP 520 from the available channel list approved by the Enabling STA 510 through the operation channel information included in the DSE status response frame 703. .

Meanwhile, the GAS frame defined in IEEE 802.11u may be used for the DSE status query frame 701 transmitted by the enabling STA 510 and the DSE status response frame 703 transmitted by the dependent AP 520.

In this case, the GAS frame includes a DSE Status Query / Response element proposed by the present invention, and the DSE Status Query / Response element will be described later.

Next, the procedure in which the Enabling STA 510 receives feedback on the operating channel from the Dependent STAs 530 and 540 will be described. In this case, the dependent AP 520 may serve as a proxy of the dependent STAs 530 and 540 in a feedback procedure of operating channel information.

The Enabling STA 510 transmits the DSE Status Query Frames 705 and 713 to the Dependent AP 520.

Then, the Dependent AP 520 transmits the DSE Status Query Proxy Frames 707 and 715 to the first and second Dependent STAs 530 and 540 to deliver the query by the Enabling STA 510. Done.

At this time, the DSE status query frame 705 or the DSE status query proxy frame 707 is an enablement identifier (Enablement ID = 2) assigned by the Enabling STA 510 to the first Dependent STA 530 when the enablement is approved. It includes. In addition, the DSE status query frame 713 or the DSE status query proxy frame 715 is an enablement identifier (Enablement ID = 3) assigned by the Enabling STA 510 to the second Dependent STA 540 when the enablement is approved. It includes.

The first and second dependent STAs 530 and 540 identify the enablement identifier included in the DSE status query proxy frames 707 and 715. If the enablement identifier is an enablement identifier assigned to the first and second dependent STAs 530 and 540, the first and second dependent STAs 530 and 540 may perform DSEs corresponding to the DSE status query proxy frames 707 and 715. The status response frames 709 and 717 are transmitted to the dependent AP 520.

Then, the Dependent AP 520 transmits the DSE status response proxy frames 711 and 719 to the Enabling STA 510 to deliver the responses of the first and second Dependent STAs 530 and 540.

In this case, the DSE status response frame 709 or the DSE status response proxy frame 711 includes information on channels on which the first dependent STA 530 operates, that is, channels 21 and 23. In addition, the DSE status response frame 717 or the DSE status response proxy frame 719 includes information on channels on which the second Dependent STA 540 is operating, that is, channels 21 and 23.

In addition, the DSE status response frames 709 and 717 or the DSE status response proxy frames 711 and 719 may include information on an operation class of an operation channel and information on maximum power that can be transmitted in the operation channel.

The Enabling STA 510 is operated by the first and second Dependent STAs 530 and 540 from among available channel lists approved by the Enabling STA 510 through operation channel information included in the DSE status response proxy frames 711 and 719. Channel information can be identified.

Meanwhile, the DSE status query frames 705 and 713 transmitted by the enabling STA 510 and the DSE status response proxy frames 711 and 719 transmitted by the dependent AP 520 may include a GAS frame defined in IEEE 802.11u. Can be used. In this case, the GAS frame includes a DSE status query / response element proposed by the present invention.

In addition, the DSE status query proxy frames 707 and 715 transmitted by the Dependent AP 520 and the DSE status response frames 709 and 717 transmitted by the first and second Dependent STAs 530 and 540 are in accordance with IEEE 802.11. The defined public action frame can be used. In this case, the public action frame is a frame defined for communication between the AP and stations in the IEEE 802.11 network. This public action frame includes a DSE status query / response element proposed by the present invention, and the DSE status query / response element will be described later.

FIG. 8 illustrates an example of a procedure in which Dependent STAs of FIG. 6 feed back information on an operation channel. That is, unlike FIG. 7 described above, FIG. 8 illustrates a procedure of feeding back information on an operation channel in an environment in which there is no Dependent AP serving as a proxy.

Referring to FIG. 8, it is assumed that the first Dependent STA 620 and the second Dependent STA 630 are communicating using the 23rd channel.

When the Enabling STA 610 queries the Dependent STAs 620 and 630 for information on the operating channel, the Dependent STAs 620 and 630 feed back a response to the query.

The Enabling STA 610 transmits the DSE status query frames 801 and 805 to the first and second Dependent STAs 620 and 630.

In this case, the DSE status query frame 801 includes an enablement identifier (Enablement ID = 1) assigned by the Enabling STA 610 to the first Dependent STA 620 when the enablement is approved. In addition, the DSE status query frame 805 includes an enablement identifier (Enablement ID = 2) assigned by the Enabling STA 610 to the second Dependent STA 630 when the enablement is approved.

The first and second dependent STAs 620 and 630 identify the enablement identifier included in the DSE status query frames 801 and 805 received from the Enabling STA 610. If the enablement identifier is an enablement identifier assigned to the first and second dependent STAs 620 and 630, the first and second dependent STAs 620 and 630 may correspond to the DSE status response frames 801 and 805. 803 and 807 are transmitted to the Enabling STA 510.

In this case, the DSE status response frame 803 includes information about a channel on which the first dependent STA 620 operates, that is, channel 23. In addition, the DSE status response frame 807 includes information about a channel on which the second dependent STA 630 operates, that is, channel 23.

In addition, the DSE status response frames 803 and 807 may include information on an operation class of an operation channel and information on a maximum power that can be transmitted in the operation channel.

The Enabling STA 610 is a channel operated by the first and second Dependent STAs 620 and 630 among available channel lists approved by the Enabling STA 610 through the operation channel information included in the DSE status response frames 803 and 807. Information can be identified.

Meanwhile, the DSE status query frames 801 and 805 transmitted by the Enabling STA 610 and the DSE status response frames 803 and 807 transmitted by the first and second Dependent STAs 620 and 630 are transmitted to the IEEE 802.11af. The defined public action frame can be used. In this case, the public action frame includes a DSE status query / response element proposed by the present invention.

Hereinafter, the Enabling STA will be described in detail with respect to the DSE status query / response element proposed by the present invention in order to receive feedback on the operating channel of the Dependent AP or the Dependent STAs.

9 illustrates a structure of a DSE Status Query / Response Element according to an embodiment of the present invention. That is, the DSE status query / response element 900 may be included in a GAS frame and used for signaling between the enabling STA and the dependent AP.

Referring to FIG. 9, the DSE status query / response element 900 includes an Info ID field 910, a Length field 920, a DSE Status Query / Response Type field 930, an Enablement Identifier field 940, and an Operating Class field. 950, a Channel Number field 960, and a Constrained Maximum Transmit Power field 970. Meanwhile, the DSE status query / response element 900 may be referred to as an operating channel status query / response element.

The Info ID field 910 indicates a value indicating that the corresponding information element is a DSE status query / response element.

The Length field 920 indicates the length of remaining element fields. In this case, the value of the Length field 920 may be variable, and the minimum value is 1.

The DSE Status Query / Response Type field 930 indicates whether the corresponding information element is used to query the Dependent STA or used as a response to the query from the Dependent STA.

In addition, the DSE Status Query / Response Type field 930 indicates whether the Operating Class field 950, the Channel Number field 960, and the Constrained Maximum Transmit Power field 970 are included.

That is, description dl according to the value of the DSE Status Query / Response Type field 930 may be defined as shown in Table 1 below.

Table 1

DSE Status Query / Response Type	Description
0	DSE Status Query / Response element sent to Dependent STA for query. The DSE Status Query / Response element does not include the Operating Class field, Channel Number field, and Constrained Maximum Transmit Power field.
One	A DSE Status Query / Response element is sent from the Dependent STA as a response to the query. The DSE Status Query / Response element contains an Operating Class field, a Channel Number field, and a Constrained Maximum Transmit Power field.
2-255	Reserved

Referring to Table 1, if the DSE Status Query / Response Type field 930 is set to '0', the corresponding information element is used for querying a Dependent STA, and includes an Operating Class field, a Channel Number field, and a Constrained Maximum Transmit. Indicates that the Power field is not included.

On the other hand, if the DSE Status Query / Response Type field 930 is set to '1', the corresponding information element is used as a response by the Dependent STA, and includes an Operating Class field, a Channel Number field, and a Constrained Maximum Transmit Power field. To indicate that it is.

The Enablement Identifier field 940 indicates an identifier assigned to the Dependent STA from the Enabling STA upon approval of the enablement.

The Operating Class field 950 indicates the number of the operating class of the channel on which the Dependent STA is operating. The operation class represents an index for a set of values for wireless operation in a wireless LAN system. In this case, the values for the radio operation include a channel starting frequency, a channel spacing, a channel set, and a behavior limits set.

The Channel Number field 960 indicates the number of the channel on which the Dependent STA is operating. Here, the operating channel number is a channel number defined in the operating class of the Dependent STA.

The Constrained Maximum Transmit Power field 970 indicates the maximum power that the Dependent STA can transmit in the operating channel.

In addition, the Operating Class field 950, Channel Number field 960, and Constrained Maximum Transmit Power field 970 constitute one triplet 980, and the triplet 580 is the Length field 920. It can be repeated by the length specified in.

10 illustrates a structure of a DSE Status Query / Response Element according to another embodiment of the present invention.

That is, the DSE status query / response element 1000 may be included in a public action frame and transmitted. In addition, the DSE status query / response element 1000 may be used for signaling between the Enabling STA and the Dependent STA or signaling between the Dependent AP and the Dependent STA.

Referring to FIG. 10, the DSE status query / response element 1000 includes a Category field 1010, an Action Value field 1020, a Length field 1030, a DSE Status Query / Response Type field 1040, and an Enablement Identifier field ( 1050, an Operating Class field 1060, a Channel Number field 1070, and a Constrained Maximum Transmit Power field 1080. Meanwhile, the DSE status query / response element 1000 may also be referred to as an operating channel status query / response element.

The Category field 1010 indicates a value indicating that the frame is a public action frame.

The Action Value field 1020 indicates that the frame is a frame for DSE status query / response.

The Length field 1030, the DSE Status Query / Response Type field 1040, the Enablement Identifier field 1050, the Operating Class field 1060, the Channel Number field 1070, and the Constrained Maximum Transmit Power field 1080 are shown in FIG. 9. Are the same as the fields included in the DSE status query / response element of.

Accordingly, the Length field 1030 included in the information element 1000, the DSE Status Query / Response Type field 1040, the Enablement Identifier field 1050, the Operating Class field 1060, the Channel Number field 1070, and the Constrained The description of the Maximum Transmit Power field 1080 will be omitted.

In addition, the DSE status query / response element 1000 may be included and transmitted in an encrypted public action frame instead of a public action frame. In this case, the encrypted public action frame may further include information on an encryption key for decrypting payload information in addition to the DSE status query / response element 1000.

FIG. 11 illustrates a procedure in which an Enabling STA receives information on an operation channel of a Dependent STA using a frame including a DSE state query / response element defined in the present invention.

Referring to FIG. 11, in step 1110, the Enabling STA receives an enablement request frame from the Dependent STA.

In step 1120, the Enabling STA assigns an enablement ID to the Dependent STA requesting the enablement. The Enabling STA transmits an enablement response frame including the assigned enablement ID and available channel list information to the Dependent STA to approve the enablement.

In operation 1130, the dependent STA selects a specific channel from a list of available channels received from the Enabling STA and starts a wireless network operation using the selected channel.

In step 1140, the Enabling STA transmits a public action frame including a DSE status query element to obtain information about an operating channel of the Dependent STA. In this case, the Enabling STA may transmit a GAS frame including a DSE status query element according to an environment of a wireless network.

In step 1150, the Dependent STA analyzes an Enablement Identifier field present in a frame received from the Enabling STA. As a result of the analysis, the Dependent STA checks whether the enablement ID included in the Enablement Identifier field is the enablement ID assigned to the dependent STA.

As a result of the check, if the enablement ID included in the corresponding field is not the enablement ID assigned to the self, the dependent STA moves to step 1160. In step 1160, the Dependent STA performs a continuous operation using the current channel.

Meanwhile, as a result of the check, when the enablement ID included in the corresponding field is the enablement ID assigned to the self, the Dependent STA moves to the next step, step 1170.

In operation 1170, the dependent STA transmits a public action frame including the DSE status response element to the Enabling STA. In this case, the dependent STA may transmit a GAS frame including a DSE status response element according to a wireless network environment.

In this case, the DSE status response element includes information on an operation class and a channel number of a channel on which the Dependent STA is operating and information on the maximum power that can be transmitted in the corresponding operation channel.

In operation 1180, the Enabling STA may identify information on an operation channel of the Dependent STA using a frame received from the Dependent STA.

As described above, an embodiment of the present invention may enable the Enabling STA of the WLAN devices operating in the TVVWS to receive information about a channel being used by the Dependent STA among the available channel lists approved by the Dependent STA. Make sure

12 is a block diagram illustrating a structure of wireless LAN devices in which an embodiment of the present invention can be implemented.

Referring to FIG. 12, the wireless LAN devices include an enabling STA 1200, a dependent STA 1250, and a dependent AP (not shown).

The Enabling STA 1200 may control the controller 1205, the RF transceiver 1210, the PHY unit 1215, the MAC unit 1220, the channel manager 1225, the IP protocol unit 1230, and the location identifier 1235. Include.

The dependent STA 1250 includes a controller 1255, an RF transceiver 1260, a PHY unit 1275, and a MAC unit 270. Although not shown in the drawings, the dependent AP may include components of the enabling STA or the dependent STA.

The RF transceiver 1210 and 1260 converts a signal input from the PHY units 1215 and 1275, which are physical layers, into an RF frequency, filters and amplifies the signal, and transmits the signal through an antenna.

In addition, the RF transceiver 1210 and 1260 converts the RF signal received through the antenna into a signal that can be processed by the PHY units 1215 and 1275 through filtering and the like. On the other hand, the RF transceiver 1210, 1260 may include a switch function for switching the transmission and reception of the RF signal.

The PHY units 1215 and 1275 perform Forward Error Correction (FEC) encoding and modulation on data requested from the MAC units 1220 and 1270, which are MAC (Media Access Control) layers, and preamble and pilot ( It performs a process such as adding a signal such as a pilot) to deliver to the RF transceiver 1210, 1260.

In addition, the PHY units 1215 and 1275 perform demodulation, equalization, and FEC decoding on signals received through the RF transceiver units 1210 and 1260, and remove preambles and pilot signals added by the transmitter. It performs the role of delivering to the MAC unit 1220, 1270. For this operation, the PHY units 1215 and 1275 may include a modulator, a demodulator, an equalizer, an FEC encoder, an FEC decoder, and the like. Can be.

The MAC units 1220 and 1270 process data transmitted from the upper layer, that is, data requested to be transmitted, and output the PHY units 1215 and 1275 to handle the additional transmissions for the data transfer. .

In addition, the MAC units 1220 and 1270 process received data input from the PHY units 1215 and 1275 to the upper layer, and are in charge of additional transmissions required for the data transfer.

The IP protocol unit 1230 processes the data input from the upper layer and transfers it to the MAC units 1220 and 1270, and processes the data input from the MAC units 1220 and 1270 and then processes the data input from the upper layer. It delivers to (Upper layer).

The location identification unit 1235 performs an operation for confirming its current location.

The channel manager 1225 accesses the geographic location database using its location information identified through the location identifier 1235, and acquires a list of TVWS channels available at the corresponding location.

In addition, the channel manager 1225 selects any one channel from the TVWS channel list, and performs a wireless network operation using the selected channel.

The controllers 1205 and 1255 control the RF transceiver 1215 and 1275, the PHY units 1215 and 1275 and the MAC units 1220 and 1270 to perform their respective functions according to control signals transmitted from an upper layer.

In addition, the controllers 1205 and 1255 provide various adjustment and management functions for smoothly controlling requests and processing time points between the RF transceivers 2315 and 2375, the PHY units 2315 and 2375, and the MAC units 2320 and 2370. Do this.

In addition, the controllers 1205 and 1255 may further include a power controller (not shown) and a sensing unit (not shown) for adjusting the intensity of the transmission power. In this case, the power controller analyzes the Constrained Maximum Transmit Power field of FIG. 9 or 10 and controls the maximum power that can be transmitted based on the analyzed result.

Meanwhile, the controllers 1205 and 1255 serve to control a signaling procedure for feedback of operating channel information according to an embodiment of the present invention. Hereinafter, the operation of the components related to the signaling procedure between the Enabling STA 1200 and the Dependent STA 1250 will be described.

First, the Enabling STA 1200 generates a DSE status query frame to receive feedback on information about an operating channel of the Dependent STA 1250.

That is, the controller 1205 of the enabling STA 1200 may generate the DSE status query frame by controlling the MAC unit 1220 and the PHY unit 1215. At this time, the DSE status query frame generated by the controller 1205 includes enablement ID information.

The MAC unit 1220 processes the data transmitted from the upper layer, that is, the data requested to be transmitted, under the control of the controller 1205 and outputs the processed data to the PHY unit 1215.

The PHY unit 1215 performs FEC encoding and modulation on data received from the MAC unit 1220 which is a MAC layer. Thereafter, the PHY unit 1215 generates a frame by performing a process such as adding a signal such as a preamble and a pilot to the modulation signal, and delivers the frame to the RF transceiver 1210. Do this.

The RF transceiver 1210 converts a frame input from the PHY unit 1215, which is a physical layer, into an RF frequency, and then filters and amplifies the frame.

Meanwhile, the dependent STA 1250 receives a DSE status query frame from the enabling STA 1200 and transmits a DSE status response frame corresponding to the DSE status query frame.

That is, the RF transceiver 1260 of the dependent STA 1250 converts the RF signal received through the antenna into a digital signal that can be processed by the PHY unit 1265 through filtering or the like.

The PHY unit 1265 performs demodulation, equalization, and FEC decoding on the frame received through the RF transceiver 1260 and removes the added preamble and pilot signal, thereby performing data bits. Output Thereafter, the PHY unit 1265 transfers the output data bit to the MAC unit 1270.

The MAC unit 1270 processes the received data input from the PHY unit 1265 and delivers the received data to the upper layer.

The controller 1255 may control operations of the MAC unit 1270, the PHY unit 1265, and the RF transceiver 1260 to obtain corresponding information from the DSE status query frame. That is, the controller 1255 analyzes the Enablement Identifier field of the DSE status query frame and checks whether the enablement ID included in the field is the enablement ID assigned to the controller.

As a result of the check, when the enablement ID included in the corresponding field is the enablement ID assigned to the controller, the controller 1255 of the Dependent STA 1250 may include a DSE state including information about a channel on which it operates. Create a response frame.

That is, the controller 1255 may generate the DSE status response frame by controlling the MAC unit 1270 and the PHY unit 1265. In this case, the DSE status response frame generated by the controller 1255 includes information on an operation class and a channel number of an operation channel and information on the maximum power that can be transmitted in the operation channel.

The MAC unit 1270 processes the data transmitted from the upper layer, that is, the data requested to be transmitted, under the control of the controller 1255, and then outputs the data to the PHY unit 1265.

The PHY unit 1265 performs FEC encoding and modulation on data received from the MAC unit 1270, which is a MAC layer. Thereafter, the PHY unit 1265 generates a frame by performing a process such as adding a signal such as a preamble and a pilot to the modulated signal, and delivers the frame to the RF transceiver 1260. Do this.

The RF transceiver 1260 converts a frame input from the PHY unit 1265, which is a physical layer, into an RF frequency, and then filters, amplifies, and transmits the frame through an antenna.

The Enabling STA 1200 receives the DSE status response frame transmitted through the antenna of the Dependent STA 1250, and analyzes it to identify information on the operation channel of the Dependent STA.

That is, the RF transceiver 1210 of the Enabling STA 1200 converts the RF signal received through the antenna into a digital signal that can be processed by the PHY unit 1215 through filtering or the like.

The PHY unit 1215 performs demodulation, equalization, and FEC decoding on the frame received through the RF transceiver 1210 and removes the added preamble and pilot signal, thereby performing data bits. Output Thereafter, the PHY unit 1215 transfers the output data bit to the MAC unit 1220.

The MAC unit 1220 processes the received data input from the PHY unit 1215 and transfers the received data to the upper layer. In this case, the data includes information on the operation channel of the Dependent STA.

The controller 1205 may control operations of the MAC unit 1220, the PHY unit 1215, and the RF transceiver 1210 to obtain corresponding information from the DSE status response frame.

That is, the controller 1205 may identify the information on the operating channel of the dependent STA by analyzing the Operating Class field, the Channel Number field, and the Costrained Maximum Power field in the DSE status response frame.

On the other hand, at least some of the methods according to an embodiment of the present invention can be stored in a computer-readable recording medium produced as a program for execution in a computer, examples of the computer-readable recording medium are ROM, RAM CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, and the like, and also include those implemented in the form of carrier waves (eg, transmission over the Internet).

The computer readable recording medium can be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. In addition, functional programs, codes, and code segments for implementing the method can be easily inferred by programmers in the art to which the present invention belongs.

On the other hand, while the specific embodiments of the present invention have been described, various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below, but also by those equivalent to the claims.

That is, the detailed description of the above-described invention shows an implementation example applied to a wireless LAN system using a TV white space. However, the present invention can be applied to other wireless communication systems using similar technical backgrounds and TV white spaces without departing from the scope of the present invention, which can be determined by those skilled in the art. It will be possible.

Claims (18)

1. Receiving an enablement request frame from at least one Dependent STA;

   Approving an enablement request by transmitting an enablement response frame corresponding to the received enablement request frame;

   Transmitting a first frame for requesting information on an operation channel of the at least one dependent STA to the at least one dependent STA; And

   Receiving a second frame corresponding to the first frame, and identifying operating channel information of the at least one dependent STA using the second frame.
2. The method of claim 1,

   The Enabling STA and the at least one Dependent STA performs a wireless network operation using a TV white space band, the channel information identification method of the Enabling STA.
3. The method of claim 1,

   The enablement response frame may include enablement ID information for identifying the at least one dependent STA and channel information usable by the at least one dependent STA. .
4. The method of claim 1,

   The first frame and the second frame is a channel identification method of the Enabling STA, characterized in that the Generic Advertisement Service (GAS) frame or a Public Action Frame (Public Action Frame).
5. The method of claim 1,

   Wherein the first frame and the second frame include an Operating Channel Status Query / Response Element.
6. The method of claim 5,

   The operation channel state query / response element includes channel ID identification information of the at least one Dependent STA.
7. The method of claim 5,

   The operating channel state query / response element may be used to determine whether the enabling STA is used for querying the operating channel of the at least one dependent STA or whether the at least one dependent STA is used as a response to the query. Channel information identification method of the Enabling STA comprising the information on.
8. The method of claim 7, wherein

   When the operating channel state query / response element is used by the at least one Dependent STA in response to the query,

   The operation channel state query / response element includes information on an operation class and a channel number of an operation channel and information on maximum power that can be transmitted in an operation channel.
9. The method of claim 1, wherein receiving the second frame comprises:

   And receiving the second frame transmitted from the at least one dependent STA through at least one dependent AP.
10. Receiving an enablement request frame from at least one Dependent STA, transmitting an enablement response frame corresponding to the received enablement request frame, and requesting information on an operation channel of the at least one Dependent STA; An RF transceiver for transmitting one frame to the at least one Dependent STA and receiving a second frame corresponding to the first frame; And

    And a control unit for identifying operating channel information of the at least one dependent STA using the second frame received from the at least one dependent STA.
11. The method of claim 10,

    And the enabling STA and the at least one dependent STA perform a wireless network operation using a TV white space band.
12. The method of claim 10,

    The enablement response frame may include enablement ID information for identifying the at least one dependent STA and channel information usable by the at least one dependent STA. .
13. The method of claim 10,

    And the first frame and the second frame are Generic Advertisement Service (GAS) frames or public action frames.
14. The method of claim 10,

    And the first frame and the second frame include an operating channel status query / response element.
15. The method of claim 14,

    And wherein the operating channel state query / response element includes enablement ID information of the at least one dependent STA.
16. The method of claim 14,

    The operating channel state query / response element may be used to determine whether the enabling STA is used for querying the operating channel of the at least one dependent STA or whether the at least one dependent STA is used as a response to the query. Device for identifying the channel information of the Enabling STA, characterized in that it comprises information.
17. The method of claim 16,

    When the operating channel state query / response element is used by the at least one Dependent STA in response to the query,

    The operation channel state query / response element includes information on an operation class and a channel number of an operation channel and information on maximum power that can be transmitted in an operation channel.
18. The method of claim 10, wherein the RF transceiver,

    And receiving the second frame transmitted from the at least one dependent STA through at least one dependent AP.

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