KR101257111B1 - Method and apparatus for selective silencing in mesh network - Google Patents

Abstract

In the selective silencing method in a WLAN mesh network, a base service set (BSS) and a wireless distribution system of a field included in a control field to distinguish between a silencing node and an activation node are provided. One of the fields used to distinguish a distribution system (WDS) is set to indicate the WDS, and the set control field and a duration field used to allocate a network allocation vector (NAV) are included. Transmitted frames.

CTS-to-Self, STA, MP, MAP, Selective Silencing

Description

METHOD AND APPARATUS FOR SELECTIVE SILENCING IN MESH NETWORK}

1 illustrates a MAP, MP and STA entity in accordance with an embodiment of the present invention;

2 illustrates a structure of a CTS frame according to an embodiment of the present invention;

3 illustrates a frame control field according to an embodiment of the invention;

4 is a flowchart illustrating a selective silencing process of a MAP according to an embodiment of the present invention;

5 is a flowchart illustrating a process of silencing by an STA according to an embodiment of the present invention; And

6 is a flowchart illustrating a process of activating an MP according to an embodiment of the present invention.

The present invention relates to a selective silencing method and system in a WLAN mesh network, and more particularly, to silencing a node that cannot forward / relay traffic in a STA (ie, a wireless local area network) using a control frame. And a method for activating a mesh point (MP), that is, a node capable of forwarding / relaying to another MP in a WLAN.

The WLAN mesh network is based on the Wireless Distribution System (WDS) of the IEEE 802.11 DS (Distribution System). A WLAN mesh network is composed of two or more sets connected to each other, and communicates between mesh links through a WLAN mesh service.

Meanwhile, an access point (AP) refers to an entity that provides access to a distribution service through a wireless medium to STAs associated with each other. Mesh Access Point (MAP) provides the functionality of this AP in a mesh network.

In the mesh network service, data must be transmitted between MPs, and an STA may cause an interruption. However, in the prior art, it is difficult to activate the MP without being disturbed by the STA in the MP (including the MAP).

Conventional WLAN systems can exchange messages by means of a network allocation vector (NAV). Here, the frame is transmitted including a 'duration field' indicating the duration of the expected message. At this time, all receivers other than the intended destination can control the transmission until the expiration of the NAV by setting the NAV.

However, the existing control frame is a frame for the wireless LAN does not have a control function for the mesh network. In addition, when a mesh control function is added by changing an existing frame, a problem that hardware may not recognize by an STA may occur. In addition, even if the hardware can be recognized, as the control information increases, the amount to be transmitted increases, thereby reducing network efficiency.

Therefore, the present invention by using the CTS (Clear-to-Send) frame, which is a conventional control frame, by silence the STA from the MP or MAP to the CTS-to-Self, without interfering with the mesh network traffic from the STA, only the MP It is intended to provide an optional silencing method that activates. In this case, the CTS frame may be replaced with a control frame including a duration field. In addition, the MP or the MAP may silence the STA and activate only the MP.

In the method of the present invention, in a selective silencing method in a WLAN mesh network, a base service set (BSS) and a wireless distribution among a field included in a control field to distinguish between a silencing node and an activation node Setting any one of the fields used to identify a Wireless Distribution System (WDS) to indicate the WDS; And transmitting a frame including the set control field and a duration field used for allocating a network allocation vector (NAV).

Another method of the present invention is a selective silencing method in a WLAN mesh network, the method comprising: receiving a frame including a control field and a duration field; Detecting that one of the fields used to distinguish a base service set (BSS) and a wireless distribution system (WDS) among the fields included in the control field indicates a WDS; ; And determining whether to allocate a network allocation vector (NAV) using the duration field.
The apparatus of the present invention is a device for performing selective silencing in a WLAN mesh network, to distinguish between a silencing node and an activation node, a base service set (BSS) among fields included in a control field And a controller configured to indicate one of the fields used to distinguish a wireless distribution system (WDS) to indicate the WDS; And a transmitter for transmitting a frame including the set control field and a duration field used for allocating a network allocation vector (NAV).

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According to another aspect of the present invention, there is provided an apparatus for performing selective silencing in a WLAN mesh network, comprising: a receiver for receiving a frame including a control field and a duration field; And detecting one of the fields used for distinguishing a base service set (BSS) and a wireless distribution system (WDS) from among the fields included in the control field. And a controller for determining whether to allocate a network allocation vector (NAV) using the duration field.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same elements in the figures are represented by the same numerals wherever possible. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

Entity of the Invention: MAP, MP, STA

First, the MAP, MP, and STA entities will be described with reference to FIG. 1. 1 is a diagram illustrating a MAP, MP, and STA entity according to an embodiment of the present invention.

The MAP 100 is a node to which an AP function is added in the mesh network, and the MP 110 is a mesh node having no access function. The MAP 100 and the MP 110 constitute a wireless distribution system (WDS) 140.

The STA 120 refers to a node without an AP function through which messages are transmitted and received in 802.11. The STA 120 and the MAP 100 configure a base station service set (BSS) (hereinafter, referred to as a 'BSS') 130.
Embodiments of the present invention provide a method of activating 105 traffic of WDS 140 and silencing 115 traffic of BSS 130. Furthermore, embodiments of the present invention enable selective silencing without changing the configuration of the CTS frame, which is an existing control frame.

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<CTS Frame>

2 is a diagram illustrating a structure of a CTS frame according to an embodiment of the present invention.

The present invention performs selective silencing through the CTS-to-Self in the MP (110) or MAP (100). Here, the CTS-to-Self means a CTS frame 200 whose RA (Remote Address) is its Media Access Control (MAC) address. The present invention uses a frame control field 210 and a duration field 220 of the CTS frame 200. The frame control field 210 is used to distinguish between the BSS 130 and the WDS 140 using (To DS, From DS) fields therein. The duration field 220 is used to allocate the NAV to each of the STA 120 of the BSS 130 and the MP 110 of the WDS 140. Since the CTS frame 200 is a representative example of a control frame, the present invention can use other control frames in addition to the CTS frame 200, and indicates that the (To DS, From DS) field is also WDS 140 traffic. Can be replaced with other bits or flags to bet.

<Frame control field of CTS frame>

3 is a diagram illustrating a frame control field according to an embodiment of the present invention. The frame control field 210 includes a (To DS, From DS) field 300 and is set in the CTS frame 200.

In general, (To DS, From DS) = (0, 0) indicates BSS 130 traffic between STAs 120. In addition, the value (0, 0) may be used as a management frame or a control frame. And (To DS, From DS) = (1, 0) or (To DS, From DS) = (0, 1) can be used as a data frame coming from or out of the DS.

According to an embodiment of the present invention, when the (To DS, From DS) field has a value other than (0, 0), the control frame is the WDS 140, that is, the MAP 100 and the MP 110 in the mesh network. It is used for communication. That is, when the value of the (To DS, From DS) field of the control frame is not (0, 0), the function of the control frame may be extended for communication between the MAP 100 and the MP 110.

<Activation of STA Silence and MP through NAV Assignment>

The embodiment of the present invention sets the value of the (To DS, From DS) field to a value other than (0, 0) in order to set that the MAP 100 is mesh traffic activating only the MP 110. For example, when the value of the (To DS, From DS) field is not (0, 0), the STA 120 may set the value of the NAV as the duration field to represent 305 microseconds as "000_0001_0011_0001_." If so, the STA is silent for 305 microseconds.

On the other hand, if the value of the (To DS, From DS) field is not (0, 0), the MP 110 sets the NAV to zero. Therefore, the MP 110 does not update the NAV, and the MP 110 may deliver the data frame without delay as indicated by the NAV.

<Optional silencing of MAP>

4 is a flowchart illustrating a selective silencing process of a MAP according to an embodiment of the present invention. Since the MP 110 may also perform CTS-to-Self as with the MAP 100, the selective silencing process of the MAP 100 may be equally possible in the MP 110. In the embodiment of the present invention, for example, selective silencing of the MAP 100 will be described.

Referring to FIG. 4, in step 400, the MAP 100 sets a different value from (0,0) to indicate that the (To DS, From DS) field is mesh traffic. In step 410, the MAP 100 transmits a CTS-to-Self frame. Since the transmission is to transmit a control frame, it can be broadcast.

In the embodiment of the present invention, a CTS frame is typically used among control frames. Thus, the CTS frame can be replaced with other control frames. In addition, an embodiment of the present invention indicates that mesh traffic is performed using a (To DS, From DS) field in a control frame. Accordingly, the (To DS, From DS) field may be replaced with another bit or flag that may indicate that the mesh is traffic.

The STA 120 and the MP 110 receive the transmitted (broadcasted) CTS frame. A flowchart of selective silencing in relation to the reception of the CTS frame is described with reference to FIGS. 5 and 6.

<STA Silencing>

5 is a flowchart illustrating a process of silencing by an STA according to an embodiment of the present invention.

Referring to FIG. 5, in step 500, the STA 120 receives a CTS frame broadcast from the MAP 100. Here, the CTS frame is set differently from the (To DS, From DS) field value to (0,0). In step 510, the STA 120 confirms that the (To DS, From DS) field value is not (0, 0) in the CTS frame and confirms that it is mesh network traffic. In step 520, the STA 120 sets during the duration field of the CTS frame receiving the NAV. The setting of the NAV is to be silenced as instructed by the MAP 100. Accordingly, the STA 120 waits in a silencing state for a time corresponding to microseconds of the duration field value.

<MP Activation>

6 is a flowchart illustrating a process of activating an MP according to an embodiment of the present invention.

Referring to FIG. 6, in step 600, the MP 110 receives a CTS frame broadcast from the MAP 100. In step 610, the MP 110 confirms that the value of the (To DS, From DS) field of the CTS-to-Self frame is not (0, 0). For example, if the value of the (To DS, From DS) field of the CTS frame is (1,1), the MP 110 checks that the value of the (To DS, From DS) field is not (0,0) and thus WDS. It can be recognized as traffic. In step 620, the MP 110 does not update the NAV. This allows MP to be activated.

On the other hand, in the detailed description of the present invention has been described with respect to specific embodiments, it can be modified in various ways without departing from the scope of the invention. The accompanying drawings show an example of applying an embodiment of the present invention, the present invention is not limited to the above-described embodiment. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

According to the present invention, by enabling selective silencing, only the STA of the MP and the STA using the same channel can be silenced, and the MP can be activated.

Claims (20)

In the selective silencing method in a WLAN mesh network, To distinguish between the silencing node and the activating node, any of the fields used to distinguish a base service set (BSS) and a wireless distribution system (WDS) among the fields included in the control field. Setting one to indicate the WDS; And And transmitting a frame including the set control field and a duration field used to allocate a network allocation vector (NAV). The frame is a clear-to-send (CTS) frame, and the RA (Remote Address) of the CTS frame is a media access control (MAC) address of the CTS frame. delete The method of claim 1, Selective silencing method, characterized in that (To DS, From DS) field of the fields included in the control field is used to distinguish the BSS and the WDS. The method of claim 3, And the (To DS, From DS) field is set to a value different from the (0,0) value. In the selective silencing method in a WLAN mesh network, Receiving a frame including a control field and a duration field; Detecting that one of the fields used to distinguish a base service set (BSS) and a wireless distribution system (WDS) among the fields included in the control field indicates a WDS; ; And Determining whether to allocate a network allocation vector (NAV) using the duration field; The frame is a clear-to-send (CTS) frame, and the RA (Remote Address) of the CTS frame is a media access control (MAC) address of the CTS frame. delete The method of claim 5, Selective silencing method, characterized in that (To DS, From DS) field of the fields included in the control field is used to distinguish the BSS and the WDS. The method of claim 7, wherein And the (To DS, From DS) field is set to a value different from the (0,0) value. The method of claim 5, And when the NAV is allocated, updates the duration field by setting the value of the duration to the NAV and maintains a silencing state for a time according to the set NAV. The method of claim 5, If the NAV is not assigned, selective silencing method characterized in that it remains active without updating the NAV. An apparatus for performing selective silencing in a WLAN mesh network, To distinguish between the silencing node and the activating node, any of the fields used to distinguish a base service set (BSS) and a wireless distribution system (WDS) among the fields included in the control field. A controller for setting one to indicate the WDS; And A transmitter for transmitting a frame including the set control field and a duration field used to allocate a network allocation vector (NAV), The frame is a clear-to-send (CTS) frame, the RA (Remote Address) of the CTS frame is a selective silencing device, characterized in that the Media Access Control (MAC) address of the CTS frame. delete 12. The method of claim 11, Selective silencing device, characterized in that the (To DS, From DS) field of the fields included in the control field is used to distinguish the BSS and the WDS. 14. The method of claim 13, And the (To DS, From DS) field is set to a value different from the (0,0) value. An apparatus for performing selective silencing in a WLAN mesh network, A receiver for receiving a frame including a control field and a duration field; And Detecting that any one of the fields used to distinguish a base service set (BSS) and a wireless distribution system (WDS) among the fields included in the control field indicates a WDS, A controller for determining whether to allocate a network allocation vector (NAV) using the duration field; The frame is a clear-to-send (CTS) frame, the RA (Remote Address) of the CTS frame is a selective silencing device, characterized in that the Media Access Control (MAC) address of the CTS frame. delete 16. The method of claim 15, Selective silencing device, characterized in that the (To DS, From DS) field of the fields included in the control field is used to distinguish the BSS and the WDS. 18. The method of claim 17, And the (To DS, From DS) field is set to a value different from the (0,0) value. 16. The method of claim 15, And when the NAV is allocated, updates the duration field by setting the value of the duration to the NAV, and maintains a silencing state for a time according to the set NAV. 16. The method of claim 15, And when the NAV is not assigned, remain active without updating the NAV.

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