KR101539233B1 - Method and apparatus for controlling a link margin - Google Patents

Abstract

An embodiment of the present invention is a method for receiving a link margin response frame from a second device, the link margin response frame including information about a link margin for a communication link between a first device and a second device, A link margin control method for performing at least one operation of changing a transmission power, changing a modulation and coding scheme, performing beamforming, and changing the communication link to another frequency band is disclosed.

Description

TECHNICAL FIELD [0001] The present invention relates to a link margin control method and apparatus,

The present invention relates to a link margin control method and apparatus therefor.

Generally, in a data communication system, a link adaptation method is a method for increasing the overall transmission capacity of a system by changing a modulation and coding scheme (MCS) according to the state of a link in which transmission and reception are performed .

At this time, a link margin may be used to determine the state of the link in which the transmission / reception is performed. The link margin in a wireless communication system represents the difference between the receiver's sensitivity and the actual received power, and the unit is dB. For example, having a 20 dB link margin means that the system can tolerate an additional 15 dB attenuation between the transmit and receive ends.

Conventionally, there has been a method of controlling the link margin by changing the modulation and coding scheme only when the link state is bad based on the link margin.

It is an object of the present invention to provide a link margin control method and apparatus therefor.

According to an aspect of the present invention, there is provided a method of controlling link margins between devices supporting communication in one or more frequency bands, the method comprising: Receiving a link margin response frame including information from the second device; And performing at least one of operations of changing a transmission power, changing a modulation and coding scheme, performing beamforming, and changing the communication link to another frequency band based on the received link margin response frame do.

Preferably, the link margin control method further includes transmitting a link margin request frame requesting information on the link margin to the second device, Is received in response to the link margin request.

Preferably, the link margin request frame includes a category field indicating which type of frame the link margin request frame belongs to, and a link margin request frame indicating a link margin request frame among the frames determined by the category field An Action field, and a Dialog Token field including an identifier for identifying the link margin request frame.

Advantageously, said link margin response frame is periodically received from said second device or received based on a calculation result of a link margin for said communication link calculated in said second device.

Advantageously, the link margin response frame is one of a preferred one of the second device's preferred one of changing the transmission power, changing the modulation and coding scheme, performing the beamforming, and changing the communication link to another frequency band. And a preferred action field indicating an operation.

Preferably, the link margin response frame is a category field indicating which type of frame the link margin response frame belongs to, and the link margin response frame indicates a link margin response frame among the types of frames determined by the category field. An action token, a dialog token field indicating whether the link margin response frame is received in response to a link margin request frame requesting information on the link margin, and a link margin including information on the link margin Element field.

Preferably, the link margin element field includes an element ID field indicating that the link margin element field is a field including information on the link margin, a length field indicating a length of the link margin element field, And a link margin field in which < RTI ID = 0.0 > a < / RTI >

Preferably, the link margin response frame is a category field indicating which type of frame the link margin response frame belongs to, and the link margin response frame indicates a link margin response frame among the types of frames determined by the category field. An action field, a dialog token field including an identifier for identifying the link margin response frame, whether the link margin response frame is received corresponding to a link margin request frame requesting information on the link margin, And a link margin element field including information on the link margin.

Preferably, the link margin response frame includes a data frame ID field including a sequence number of a data frame used when the second device is received by the second device immediately before the second device transmits the link margin response, .

According to another aspect of the present invention, there is provided a method for controlling a link margin for a communication link with a second device of a first device in a network including devices supporting communication in one or more frequency bands The apparatus comprising: a receiving unit for receiving a link margin response frame from the second device, the link margin response frame including information on a link margin for a communication link between the first device and the second device; And an operation performing unit operable to perform at least one operation of changing a transmission power, changing a modulation and coding scheme, performing beamforming, and changing the communication link to another frequency band based on the received link margin response frame .

Preferably, the link margin control apparatus further includes a transmission unit for transmitting a link margin request frame requesting information on the link margin to the second device, Is received in response to the link margin request.

According to another aspect of the present invention, there is provided a method for transmitting a link margin response frame, the method comprising: receiving a link margin response frame from the second device, the link margin response frame including information on a link margin for a communication link between the first device and the second device; And performing at least one of operations of changing a transmission power, changing a modulation and coding scheme, performing beamforming, and changing the communication link to another frequency band based on the received link margin response frame A program for implementing a link margin control method is recorded

Readable recording medium.

FIG. 1 is a flowchart illustrating a link margin control method according to an embodiment of the present invention. Referring to FIG.
FIG. 2 is a diagram illustrating a structure of a link margin request frame according to an embodiment of the present invention. Referring to FIG.
3 is a diagram illustrating a structure of a link margin response frame according to an embodiment of the present invention.
4 is a diagram illustrating a structure of a link margin element field according to an embodiment of the present invention.
5 is a diagram illustrating a structure of a link margin element field according to a second embodiment of the present invention.
6 is a diagram illustrating a structure of a link margin response frame according to a second embodiment of the present invention.
7 is a diagram illustrating a structure of a link margin response frame according to the third embodiment of the present invention.
FIG. 8 is a diagram illustrating a structure of a link margin response frame according to the fourth embodiment of the present invention.
9 is a view for explaining a link margin control apparatus according to an embodiment of the present invention.

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

FIG. 1 is a flowchart illustrating a link margin control method according to an embodiment of the present invention. Referring to FIG.

Hereinafter, a method in which a first device controls a link margin for a communication link with a second device in a network including a first device and a second device supporting communication in one or more frequency bands will be described.

In step 110, the first device sends a link margin request frame to the second device requesting information on the link margin for the communication link between the first device and the second device.

At this time, the first device and the second device can communicate in the 2.4 GHz and 60 GHz frequency bands, in the 5 GHz and 60 GHz frequency bands, in the 2.4 GHz, 5 GHz and 60 GHz frequency bands, .

The structure of the link margin request frame will be described later with reference to FIG.

In step 120, the first device receives a link margin response frame from the second device that includes information about its link margin.

At this time, the link margin response frame may be received from the second device corresponding to the link margin request frame transmitted in step 110. [

In another embodiment, step 110 may be omitted, in which case the first device may receive the link margin response frame unilaterally from the second device without transmitting the link margin request frame to the second device.

For example, the second device may periodically transmit a link margin response frame to the first device. The second device may continuously calculate a link margin for the communication link, and may transmit a link margin response frame to the first device when it is determined that the link status is bad according to the calculation result.

Here, the second device can calculate the link margin using the difference between the signal-to-noise ratio measured at the second device and the signal-to-noise ratio appropriate for the modulation and coding scheme (MCS) of the currently received data, But is not limited thereto.

The structure of the link margin response frame will be described later with reference to FIG . 3 to FIG .

In step 130, based on the received link margin response frame, the first device changes the transmission power, changes the modulation and coding scheme (MCS), performs beamforming, And at least one of the changes is performed.

At this time, when the first device determines that the link state is bad based on the link margin response frame, the first device changes the transmission power, changes the modulation and coding scheme (MCS), performs beamforming, The link margin is controlled by selecting the most appropriate operation among the changes of the link.

For example, assuming that the first device and the second device can use the 2.4 GHz or 5 GHz frequency band and the 60 GHz frequency band, the first device is performing communications in the 60 GHz frequency band, It is possible to perform communication by changing the frequency band to 2.4 GHz or 5 GHz using FST (Fast Session Transfer) technology. Also, when the first device performs communication in the frequency band of 2.4 GHz or 5 GHz and it is determined that the state of the communication link with the second device in the frequency band is bad, the first device uses the FST (Fast Session Trasfer) It is possible to perform communication by changing the frequency band. However, the first device may perform more than two operations, including changing the communication link to another frequency band to control the link margin. A detailed description of the FST technique is described in the WGA Specification, and a detailed description thereof will be omitted.

As described above, according to one embodiment of the present invention, when it is determined that the link state is bad based on the link margin, the method of changing the modulation and coding scheme (MCS) It is possible to control the link margin using the most appropriate operation among the change of the coding scheme (MCS), the beamforming, and the change of the communication link to the other frequency bands. Therefore, Can be controlled.

In another embodiment, the second device is one of the preferred operations of changing the transmission power, changing the modulation and coding scheme (MCS), performing beamforming, and changing the communication link to another frequency band in the link margin response frame May be included. In such a case, the first device may perform an operation according to a preference operation of the second device included in the link margin response frame, or may perform a desired operation of the first device regardless of a preference operation of the second device .

FIG. 2 is a diagram illustrating a structure of a link margin request frame according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 2, a link margin request frame 200 according to an embodiment of the present invention includes a category field 210, an action field 220, and a dialogue token field 230.

The category field 210 indicates to which type of frame the link margin request frame 200 belongs.

For example, the type of frame is the management frame. A control frame, and a data frame. Since the link margin request frame 200 will be included in the control frame, the category field 210 will indicate that the link margin request frame 200 is a control frame.

The action field 220 indicates that the link margin request frame 200 is a link margin request frame 200 among the control frames that are frame types defined by the category field 201. [

For example, if 8 is recorded in the action field 220, it may indicate that the frame is a link margin request frame 200 and 9 may indicate that it is a link margin response frame.

The dialogue token field 230 includes an identifier for identifying the link margin request frame 200 to be transmitted when the first device transmits the link margin request frame 200 to the second device. At this time, the first device may set an arbitrary value other than 0 in the question token field 230 as an identifier for identifying the link margin request frame 200.

However, the structure of the link margin request frame 200 is not limited to the embodiment of FIG. 2, and some of the fields 210, 220, and 230 may be omitted, or new fields may be added.

Hereinafter, a structure of a link margin response frame according to an embodiment of the present invention will be described with reference to FIG. 3 to FIG.

3 is a diagram illustrating a structure of a link margin response frame according to an embodiment of the present invention.

3, a link margin response frame 300 according to an exemplary embodiment of the present invention includes a category field 310, an action field 320, a request reception field 330, and a link margin element field 340 do.

The category field 310 indicates what type of frame the link margin response frame 300 belongs to.

In the embodiment of FIG. 3, the category field 310 will indicate that the link margin response frame 300 is a control frame.

The action field 320 indicates that the link margin response frame 300 is among the control frames, which is a frame type determined by the category field 310, from among the control frames.

The Dialog Token field indicates whether the link margin response frame 300 is received corresponding to the link margin request frame 200 requesting information on the link margin.

For example, if the link margin response frame 300 is received corresponding to the link margin request frame 200, a non-zero value may be recorded in the dialogue token field, If the link margin request frame 200 is received without transmitting the link margin request frame 200, a 0 may be written in the question token field 330. [ However, the value recorded in the question token field 330 is not limited thereto, and in each case, a predetermined value may be recorded in the question token field 330. [

The link margin element field 340 contains information about the link margin.

The structure of the link margin element field 340 will be described with reference to Figs. 4 and 5. Fig.

4 is a diagram illustrating a structure of a link margin element field according to an embodiment of the present invention.

Referring to FIG. 4, the link margin element field 340 according to an embodiment of the present invention includes an element ID field 342, a length field 344, and a link margin field 346.

The element ID field 342 indicates that the link margin element field 340 is a field including information on the link margin.

The length field 344 indicates the length of the link margin element field 340.

In the link margin field 346, information on the link margin calculated by the second device is recorded.

5 is a diagram illustrating a structure of a link margin element field according to a second embodiment of the present invention.

5, a link margin element field 340 according to an exemplary embodiment of the present invention includes an element ID field 341, a length field 342, a preferred action field 343, an MCS field 344, Field 345. < / RTI >

The element ID field 341 indicates that the link margin element field 340 is a field including information on the link margin.

The length field 342 indicates the length of the link margin element field 340.

The preferred action field 343 indicates one operation preferred by the second device among the changes of the transmit power, the modulation and coding scheme (MCS), the beamforming, and the change of the communication link to another frequency band.

For example, if 0 is written in the preferred action field 343, it indicates that there is no preferred operation of the second device. If 1 is recorded, it indicates that the preferred operation of the second device is a change of the modulation and coding scheme (MCS) The preferred operation of the second device indicates that the transmission power is changed, and if 3 is recorded, the second device's preferred operation may indicate a change of the communication link to another frequency band, i.e., FST (Fast Session Transfer) have.

As described above, when the link margin response frame 300 including the preferred action field 343 as described above is received, the first device selects the preferred action field 343 according to the preferred operation of the second device displayed in the preferred action field 343 The first device may perform an operation, and the first device may perform a desired operation regardless of a preferred operation of the second device.

The MCS field 344 indicates the MCS value to be changed when the preferred operation of the second device is indicated as a change of the modulation and coding scheme (MCS) in the preferred action field 343.

In the link margin field 345, information on the link margin calculated by the second device is recorded. For example, the second device may calculate the link margin from the data frames received from the first device, and then write the result of the calculation to the link margin field 345. [

6 is a diagram illustrating a structure of a link margin response frame according to a second embodiment of the present invention.

Referring to FIG. 6, the link margin response frame 600 according to the second embodiment of the present invention includes a category field 610, an action field 620, a dialogue token field 630, 640 and a link margin element field 650.

The category field 610 indicates to which type of frame the link margin response frame 600 belongs. In the embodiment of FIG. 6, the category field 610 will indicate that the link margin response frame 600 is a control frame.

The action field 620 indicates that the link margin response frame 600 is the control frame, which is a type of frame determined by the category field 610, among the control frames.

The dialog token field 630 includes an identifier for identifying the transmitted link margin response frame 600 when the second device sends the link margin response frame 600 to the first device.

At this time, the link margin response frame 600 is recorded in the question token field 630 by directly recording the identifier recorded in the question token field 230 of the link margin request frame 200 corresponding to the link margin response frame 600 Indicates a link margin response frame 600 corresponding to the link margin request frame 200. [ For example, when the second device receives the link margin request frame 200 in which 1 is recorded in the question token field 230 from the first device, the second device displays a link margin The link margin response frame 600 transmitted by the second device to the first device is transmitted to the first device through the link margin request frame 200 in which 1 is written in the dialog token field 230, ≪ / RTI >

In the case where the link margin response frame 600 is not transmitted in response to the link margin request frame 200, 0 may be written in the question token field 630.

However, the value recorded in the Dialog Token field 630 is not limited to this, and in each case, a predetermined value may be recorded in the Dialog Token field 630.

The preferred action field 640 indicates one operation preferred by the second device among the changes of the transmit power, the modulation and coding scheme (MCS), the beamforming, and the change of the communication link to other frequency bands.

3 is compared with the link margin response frame 300 of FIG. 3, the link margin response frame 300 of FIG. 3 does not include the preferred action field 640, 3 may include the preferred action field 640 in the link margin element field 340 of FIG. 3 as in the embodiment of FIG. 5, so that the link margin response frame 300 of FIG. 3 and the link margin response frame 600 of FIG. 6 May include preference action fields 343 and 640, all of which are different only in the location in which the preferred action fields 343 and 640 are included.

The link margin element field 650 includes information on the link margin.

7 is a diagram illustrating a structure of a link margin response frame according to the third embodiment of the present invention.

Referring to FIG. 7, the link margin response frame 700 according to the third embodiment of the present invention includes a category field 710, an action field 720, a dialog token field 730, an unsolicited field 740 and a link margin factor field 750.

At this time, the category field 710, the action field 720, the dialog token field 730, and the link margin element field 750 correspond to the category field 610 of the link margin response frame 600 of FIG. 6, the action field 620 ), The token token field 630, and the link margin element field 650, detailed description thereof will be omitted.

The unsolicited field 740 indicates whether the link margin response frame 700 is received corresponding to the link margin request frame 200.

For example, if the link margin response frame 700 is received corresponding to the link margin request frame 200, 0 may be written in the non-request field 740, and the link margin response frame 700 may be written in the link margin request frame 200, the non-requested field 740 may be recorded with a non-zero value. However, the value recorded in the non-requested field 740 is not limited to this, and a predetermined value may be recorded in the non-requested field 740 in each case.

FIG. 8 is a diagram illustrating a structure of a link margin response frame according to the fourth embodiment of the present invention.

Referring to FIG. 8, a link margin response frame 800 according to the fourth embodiment of the present invention includes a category field 810, an action field 820, a dialog token field 830, a data frame ID field 840, And a link margin element field 850.

At this time, the category field 810, the action field 820, the dialog token field 830, and the link margin element field 850 correspond to the category field 610 of the link margin response frame 600 of FIG. 6, the action field 620 ), The token token field 630, and the link margin element field 650, detailed description thereof will be omitted.

The data frame ID field 840 contains the sequence number of the data frame used when the second device was received by the second device just before transmitting the link margin response 800 and calculating the link margin.

The second device can know the calculation time of the link margin to the first device receiving the link margin response frame 800 by using the sequence number of the data frame used when calculating the link margin, Can be controlled.

Also, in another embodiment, the number of data frames retransmitted from the first device to the second device may be recorded in the data frame ID field 840, and the link margin can be calculated using this information.

In another embodiment, the data frame ID field 840 may include a sequence number field (not shown) and a reserved field (not shown) for recording the sequence number of the data frame.

2 to 8 show the number of octets and the number of bits for each field, but an embodiment of the present invention is not limited to this.

9 is a view for explaining a link margin control apparatus according to an embodiment of the present invention.

9, the link margin control apparatus 910 includes a transmitting unit 912, a receiving unit 914, and an operation performing unit 916. Here, it is assumed that the link margin control apparatus according to an embodiment of the present invention is mounted on a first device (not shown), and the second device 920 is further illustrated for convenience of explanation. It is also assumed that each of the first device and the second device can support communication in one or more frequency bands.

The transmitting unit 912 transmits a link margin request frame requesting information on the link margin to the second device 920.

In another embodiment, the transmitter 912 may be omitted.

The receiving unit 914 receives from the second device 920 a link margin response frame including information on the link margin for the communication link between the link margin control device 910 of the first device and the second device 920 .

At this time, the link margin response frame may be received corresponding to the link margin request or unilaterally received from the second device without transmitting the link margin request.

The operation performing unit 916 is configured to change the transmission power, change the modulation and coding scheme, perform the beam forming, and change the communication link to another frequency band based on the link margin response frame received through the receiver 912 And performs at least one operation.

The above-described embodiments of the present invention can be embodied in a general-purpose digital computer that can be embodied as a program that can be executed by a computer and operates the program using a computer-readable recording medium.

The computer readable recording medium includes a magnetic storage medium (e.g., ROM, floppy disk, hard disk, etc.), optical reading medium (e.g., CD ROM, DVD, etc.).

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Claims (21)

A method for controlling a link margin between devices supporting communication in one or more frequency bands,
Receiving from the second device information about a link margin for a communication link between the first device and the second device; And
Selecting at least one of at least one of selectable operations for controlling a link margin based on information on the received link margin, a change of a transmit power, a change of a modulation and coding scheme, and a change to another frequency band of the communication link Performing a single operation,
Wherein the step of receiving information on the link margin comprises:
Receiving information about the link margin and information indicating at least one operation preferred by the second device among the change of the transmission power, the modulation and coding scheme, and the change to another frequency band of the communication link Wherein the link margin control method comprises: The method according to claim 1,
Further comprising: requesting the second device for information about the link margin,
Wherein the information about the link margin is received corresponding to the link margin request. 3. The method of claim 2,
Wherein the step of requesting information about the link margin comprises:
A category field indicating which type of frame the link margin request frame belongs to; an action field indicating that the link margin request frame is a link margin request frame among frames of a type determined by the category field; And a dialog token field including an identifier for identifying the link margin, and information about the link margin. delete delete delete delete delete delete An apparatus for controlling a link margin for a communication link with a second device of a first device in a network including devices supporting communication in one or more frequency bands,
A receiving unit for receiving information on a link margin for a communication link between the first device and the second device from the second device; And
Selecting at least one of at least one of selectable operations for controlling a link margin based on information on the received link margin, a change of a transmit power, a change of a modulation and coding scheme, and a change to another frequency band of the communication link And an operation performing unit for performing one operation,
The receiver may further comprise:
Information indicating at least one operation recommended by the second device among the change of the transmission power, the modulation and coding scheme, and the change to another frequency band of the communication link, and information on the link margin Link margin control device. 11. The method of claim 10,
Further comprising a transmitting unit for requesting the second device for information about the link margin,
Wherein the information on the link margin is received in response to the link margin request. 12. The method of claim 11,
Wherein the transmission unit comprises:
A category field indicating which type of frame the link margin request frame belongs to; an action field indicating that the link margin request frame is a link margin request frame among frames of a type determined by the category field; And a dialogue token field including an identifier for identifying the link margin, and information about the link margin. delete delete delete delete delete delete A computer-readable recording medium on which a program for implementing the method of any one of claims 1 to 3 is recorded. The method according to claim 1,
Wherein the second device transmits information on the link margin to the first device in a state in which the information about the link margin is not requested from the first device. 11. The method of claim 10,
Wherein the second device transmits information on the link margin to the first device in a state in which the information about the link margin is not requested from the first device.

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