JP6724178B2 - Data communication method and related device - Google Patents

Description

The present invention relates to the field of data communication technology, and more particularly to a data communication method and related device.

2. Description of the Related Art With the development of communication technology, a wireless local area network (WLAN) technology based on the IEEE 802.11 standard has been widely applied. Currently, various mainstream WLAN standards (such as 802.11n and 802.11ac) introduce guard intervals (GI) to eliminate inter-symbol interference caused by channel delay spread. In the process of the terminal communicating with the access device, the terminal needs to select an appropriate guard interval length to maximize intersymbol interference. The GI length used in the 802.11ac standard is 0.8 us. In the process of data communication between the access device and the terminal, the AP and STA use the preamble GI length of 0.8us and the data GI length of 0.8us.

The IEEE officially proposed the next-generation WLAN standard in May 2013, the High Efficiency WLAN (HEW), which is called 802.11ax. HEW standardization work proposes to provide more options for GI length, including GI lengths such as 3.2us, 2.4, 1.6us, 1.2us, 0.8us, 0.4us. Has been done. In HEW solutions with multiple selectable GI lengths, there is currently no way to set the GI length for data communication between terminals and access devices in HEW.

Embodiments of the present invention provide a data communication method and a related device capable of implementing data communication between an access device and a terminal when the access device supports a plurality of data guard interval lengths.

A first aspect of the present invention provides a data communication method, the method comprising constructing a beacon frame by an access device, the beacon frame including a newly added field, and the newly added field. Represents a plurality of data guard interval lengths supported by the access device, and
To enable a terminal to perform data communication with an access device by selecting from the beacon frame an available guard interval length that matches the data guard interval length supported by the terminal and using the available guard interval length. , The access device broadcasting a beacon frame,
including.

Based on the first aspect, in a first feasible implementation method, the beacon frame comprises at least one element, a particular element of the at least one element carries the newly added field and the particular element Is an existing element or a newly added element.

Based on the first feasible implementation method of the first aspect, in the second feasible implementation method, the newly added field includes an indicator index value corresponding to each preset bandwidth, The indicator value represents the minimum data guard interval length of all data guard interval lengths supported by the access device within the preset bandwidth, or a new field is added for each preset data guard interval. Length indicator bit, which is used to indicate whether the access device supports a preset data guard interval length, or a newly added field is included within each preset bandwidth. Of each of the preset data guard interval lengths, the indication bit is used to indicate whether the access device supports a preset data guard interval length within a preset bandwidth.

Based on the first aspect, in a third feasible implementation method, after the step of constructing a beacon frame by the access device, the method comprises:
Separately encapsulating the beacon frame into a first standard protocol data unit and a second standard protocol data unit by the access device,
Broadcasting the beacon frame by the access device comprises:
Broadcasting a beacon frame encapsulated in a first standard protocol data unit and a beacon frame encapsulated in a second standard protocol data unit by an access device.

Based on the third feasible implementation method of the first aspect, in the fourth feasible implementation method, the plurality of data guard interval lengths supported by the access device is supported by the access device in the first standard. The data guard interval length and the data guard interval length supported by the access device in the second standard are included, and the beacon frame is separately encapsulated by the access device in the first standard protocol data unit and the second standard protocol data unit. The steps to
By the access device, the maximum data guard interval length in the data guard interval length supported by the access device in the first standard is obtained, and the maximum data guard interval length is determined as the first alternative data guard interval length,
By the access device, obtaining the maximum data guard interval length in the data guard interval length supported by the access device in the second standard, determining the maximum data guard interval length as the second alternative data guard interval length,
Separately encapsulating the beacon frame into a first standard protocol data unit and a second standard protocol data unit by the access device according to a first alternative data guard interval length and a second alternative data guard interval length;
including.

Based on the fourth feasible implementation method of the first aspect, in the fifth feasible implementation method, the first standard protocol data unit comprises preamble and bearer data, and the bearer data comprises a beacon frame. , The guard interval length of the preamble and the guard interval length of the bearer data are the first alternative data guard interval length.

Based on the fourth feasible implementation method of the first aspect, in the sixth feasible implementation method, the second standard protocol data unit comprises a legacy preamble, a high efficiency wireless local area network preamble, and bearer data. Including the guard interval length of the legacy preamble, the guard interval length of the high-efficiency wireless local area network preamble, the guard interval length of the bearer data is the second alternative data guard interval length, respectively, or
The second standard protocol data unit includes a legacy preamble, a high efficiency wireless local area network preamble, and bearer data, the guard interval length of the legacy preamble is the first alternative data guard interval length, and the high efficiency wireless local area. The network preamble guard interval length and bearer data guard interval length are the second alternative data guard interval length, or
The second standard protocol data unit includes the high efficiency wireless local area network preamble and bearer data, and the guard interval length of the high efficiency wireless local area network preamble and the guard interval length of the bearer data are both the second alternative data guard interval. Be long.

Based on the fourth feasible implementation method of the first aspect, in the seventh feasible implementation method, in the beacon frame encapsulated in the first standard protocol data unit and the second standard protocol data unit. Prior to the step of the access device broadcasting the encapsulated beacon frame, the method comprises:
The method further includes the step of the access device adding to the first standard protocol data unit a computed field used to indicate the time of transmission of the second standard protocol data unit,
The step of the access device broadcasting the beacon frame encapsulated in the first standard protocol data unit and the beacon frame encapsulated in the second standard protocol data unit,
Broadcasting a first standard protocol data unit containing a calculated field during a preset period of time by the access device;
The access device broadcasts the second standard protocol data unit at the time of transmission indicated by the computed field;
including.

A second aspect of the present invention provides a data communication method, which is a step in which a terminal acquires a beacon frame broadcast by an access device, the beacon frame including a newly added field, and A step in which the added field represents multiple data guard interval lengths supported by the access device;
The terminal selects a usable guard interval length that matches the data guard interval length supported by the terminal from a plurality of data guard interval lengths supported by the access device,
The terminal performing data communication with the access device by using the available guard interval length;
including.

Based on the second aspect, in the first feasible implementation method, the beacon frame is encapsulated in a first standard protocol data unit and a second standard protocol data unit, and the access device is configured for a preset period of time. To the first standard protocol data unit, the first standard protocol data unit including a calculated field used to indicate the time of transmission of the second standard protocol data unit.

Based on the first feasible implementation method of the second aspect, in the second feasible implementation method, the step of the terminal acquiring the beacon frame broadcast by the access device,
The terminal obtains the first standard protocol data unit broadcasted by the access device, and analyzes the beacon frame from the first standard protocol data unit, or
The terminal obtains the second standard protocol data unit broadcasted by the access device, and analyzes the beacon frame from the second standard protocol data unit, or
The terminal acquires the first standard protocol data unit broadcast by the access device, determines the transmission time of the second standard protocol data unit from the calculation field in the first standard protocol data unit, and determines the second time according to the transmission time. Obtaining a standard protocol data unit and parsing the beacon frame from a second standard protocol data unit,
including.

A third aspect of the present invention provides an access device, the access device being a building module configured to build a beacon frame, the beacon frame including a newly added field, and the newly added The configured field represents a plurality of data guard interval lengths supported by the access device, and
A transceiver module configured to broadcast a beacon frame and to perform data communication with the terminal,
including.

According to a third aspect, in the first feasible implementation method, the beacon frame comprises at least one element, a particular element of the at least one element carries the newly added field and the particular element is , An existing element or a newly added element.

Based on the first feasible implementation method of the third aspect, in the second feasible implementation method, the newly added field includes an indicator index value corresponding to each preset bandwidth, The indication index value represents the minimum data guard interval length of all data guard interval lengths supported by the access device within the preset bandwidth, or
The newly added field contains an indicator bit for each preset data guard interval length, the indicator bit is used to indicate whether the access device supports the preset data guard interval length, or ,
The newly added field contains an indicator bit for each preset data guard interval length within each preset bandwidth, where the indicator bit is the preset data guard interval within the preset bandwidth of the access device. Used to indicate if length is supported.

Based on the third aspect, in a third feasible implementation method, the access device is configured to separately encapsulate the beacon frame into a first standard protocol data unit and a second standard protocol data unit. Further including an encapsulation module,
The transceiver module is specifically configured to broadcast a beacon frame encapsulated in a first standard protocol data unit and a beacon frame encapsulated in a second standard protocol data unit.

Based on the third feasible implementation method of the third aspect, in the fourth feasible implementation method, the plurality of data guard interval lengths supported by the access device is supported by the access device in the first standard. The encapsulation module includes a data guard interval length and a data guard interval length supported by the access device in the second standard.
A first standard configured to obtain the maximum data guard interval length in the data guard interval lengths supported by the access device in the first standard and determine the maximum data guard interval length as the first alternative data guard interval length. Acquisition unit of
A second standard configured to obtain the maximum data guard interval length in the data guard interval lengths supported by the access device in the second standard and determine the maximum data guard interval length as the second alternative data guard interval length. Acquisition unit of
Encapsulation configured to separately encapsulate a beacon frame into a first standard protocol data unit and a second standard protocol data unit with a first alternative data guard interval length and a second alternative data guard interval length. A unit,
including.

Based on the fourth feasible implementation method of the third aspect, in the fifth feasible implementation method, the first standard protocol data unit comprises preamble and bearer data, and the bearer data comprises a beacon frame. , The guard interval length of the preamble and the guard interval length of the bearer data are the first alternative data guard interval length.

Based on the fourth feasible implementation method of the third aspect, in the sixth feasible implementation method, the second standard protocol data unit comprises a legacy preamble, a high efficiency wireless local area network preamble, and bearer data. Including the guard interval length of the legacy preamble, the guard interval length of the high-efficiency wireless local area network preamble, the guard interval length of the bearer data is the second alternative data guard interval length, respectively, or
The second standard protocol data unit includes a legacy preamble, a high efficiency wireless local area network preamble, and bearer data, the guard interval length of the legacy preamble is the first alternative data guard interval length, and the high efficiency wireless local area. The network preamble guard interval length and bearer data guard interval length are the second alternative data guard interval length, or
The second standard protocol data unit includes the high efficiency wireless local area network preamble and bearer data, and the guard interval length of the high efficiency wireless local area network preamble and the guard interval length of the bearer data are both the second alternative data guard interval. Be long.

Based on the fourth feasible mounting method of the third aspect, in the seventh feasible mounting method, the access device,
Further comprising a processing module configured to add to the first standard protocol data unit a math field used to indicate the time of transmission of the second standard protocol data unit,
The transceiver module is specifically configured to broadcast a first standard protocol data unit including a math field for a preset period of time,
The transceiver module is further configured to broadcast the second standard protocol data unit at the transmission time indicated by the computed field.

A fourth aspect of the present invention provides a terminal, the terminal comprising:
A transceiver module configured to obtain a beacon frame broadcast by an access device, wherein the beacon frame includes a newly added field, the newly added field comprising a plurality of fields supported by the access device. A transceiver module representing the data guard interval length,
A selection module configured to select an available guard interval length that matches a data guard interval length supported by the terminal from a plurality of data guard interval lengths supported by the access device,
Including
The transceiver module is further configured to communicate data with the access device by using the available guard interval length.

Based on the fourth aspect, in the first feasible implementation method, the beacon frame is encapsulated in a first standard protocol data unit and a second standard protocol data unit, and the access device has a preset period of time. To the first standard protocol data unit, the first standard protocol data unit including a calculated field used to indicate the time of transmission of the second standard protocol data unit.

Based on the first feasible implementation method of the fourth aspect, in the second feasible implementation method, the transceiver module obtains the first standard protocol data unit broadcast by the access device, Specifically configured to parse beacon frames from standard protocol data units, or
The transceiver module is specifically configured to obtain a second standard protocol data unit broadcast by the access device and parse a beacon frame from the second standard protocol data unit, or
The transceiver module obtains the first standard protocol data unit broadcast by the access device, determines the transmission time of the second standard protocol data unit from the calculated field in the first standard protocol data unit, and determines the first time according to the transmission time. Specifically configured to obtain the second standard protocol data unit and parse the beacon frame from the second standard protocol data unit.

In an embodiment of the present invention, the access device constructs a beacon frame, the beacon frame includes a newly added field, and the newly added field represents a plurality of data guard interval lengths supported by the access device, The access device broadcasts the constructed beacon frame, and the terminal selects an available guard interval length that matches the data guard interval length supported by the terminal from the beacon frame broadcast by the access device, and selects the available guard interval. Communicate with the access device by using the length. In this implementation method, in the standard that proposes a plurality of data guard interval lengths, in order to normally execute data communication between an access device and a terminal, a plurality of data guard interval lengths supported by the access device are set in a beacon frame. May be encapsulated in the newly added field of.

BRIEF DESCRIPTION OF DRAWINGS To describe the technical solutions in the embodiments of the present invention more clearly, the following briefly describes the accompanying drawings required for describing the embodiments. Apparently, the accompanying drawings in the following description show only some embodiments of the present invention, and a person skilled in the art can obtain other drawings from these accompanying drawings without spending creative effort. You can

It is a figure which shows the application scenario of the data communication method by this invention. 3 is a schematic flowchart of a data communication method according to the present invention. 3 is a schematic flowchart of another data communication method according to the present invention. 4 is a schematic flowchart of another data communication method according to the present invention. 4 is a schematic flowchart of another data communication method according to the present invention. FIG. 3 is a schematic configuration diagram of a newly added element according to the present invention. FIG. 6 is a schematic structural diagram of another newly added element according to the present invention. It is a table of data GI length supported by AP in the HEW standard. It is another table of the data GI length which AP supports in the HEW standard. It is a correspondence index table according to the present invention. FIG. 6 is a schematic configuration diagram of a newly added field according to the present invention. 6 is a table for explaining newly added fields according to the present invention. FIG. 6 is a schematic structural diagram of another newly added field according to the present invention. 5 is another table for explaining newly added fields according to the present invention. It is another table of the data GI length which AP supports in the HEW standard. FIG. 6 is a schematic structural diagram of yet another newly added field according to the present invention. 6 is another table for explaining newly added fields according to the present invention. 6 is another table for explaining newly added fields according to the present invention. This is the encapsulation format of PPDU1 in the 802.11ac standard. 3 is an encapsulation format of PPDU2 according to the present invention. 4 is a table for explaining each field in PPDU2 according to the present invention. 6 is another encapsulation format of PPDU2 according to the present invention. 5 is another table for explaining each field in PPDU2 according to the present invention. 6 is another PPDU2 encapsulation format according to the present invention. 5 is another table for explaining each field in PPDU2 according to the present invention. FIG. 3 is a diagram showing a method of broadcasting PPDU1 and PPDU2 according to the present invention. FIG. 6 is a diagram showing another broadcasting method of PPDU1 and PPDU2 according to the present invention. 1 is a schematic configuration diagram of an access device according to the present invention. FIG. 3 is a schematic configuration diagram of an encapsulation module according to the present invention. 1 is a schematic configuration diagram of a terminal according to the present invention. FIG. 9 is a schematic configuration diagram of another access device according to the present invention. It is a schematic block diagram of another terminal of this invention.

Hereinafter, technical solutions in the embodiments of the present invention will be clearly described with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely some but not all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

The access device may be an access point (AP), also called a wireless access point, hotspot, etc. APs are access points that mobile users go through as they enter the wired network; APs are primarily located in homes or buildings and parks, with a typical coverage radius of tens to hundreds of meters, Of course, you may deploy it outdoors. AP is equivalent to a bridge that connects a wired network and a wireless network. The main function of the AP is to connect all wireless network clients and connect the wireless network to Ethernet. Currently, the standard mainly used by APs is the IEEE (Institute of Electrical and Electronics Engineers) 802.11 family. Specifically, the AP may be a terminal device or a network device having a WiFi chip. Optionally, the AP may be a device supporting the 802.11ax standard, and further optionally, the AP is 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11b. It may be a device that supports multiple WLANs (wireless local area networks) such as 11a.

The terminal may be a wireless communication chip, a wireless sensor, or a wireless communication terminal. For example, the terminal may be a mobile phone that supports wireless fidelity (WiFi) communication function, a tablet computer that supports WiFi communication function, a set-top box that supports WiFi communication function, or a computer that supports WiFi communication function. Good. Optionally, the terminal may support the 802.11ax standard, and further optionally, the terminal may, such as 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a. It may support multiple WLAN standards.

In the prior art, for example, 802.11ac standard, the data GI length used in the process of data communication between AP and STA is 0.8 us. The HEW standard proposes more options for data GI length, including data GI lengths such as 0.4us, 0.8us, 1.2us, 1.6us, 2.4us, 3.2us. Therefore, the fixed data GI length of the prior art is not compatible with data communication between AP and STA in the new HEW standard. As shown in FIG. 1, if the AP supports HEW standard STA2 and STA3 and 802.11ac standard STA1, and a data GI length of 0.8 us is used between AP and STA, STA1 Since STA1 and STA2 are within the coverage area of 0.8 us, STA1 and STA2 can perform data communication with the AP. However, STA3 exceeds the coverage area of 0.8us, so data communication with AP is not possible.

The embodiment of the present invention may be applied to the application scenario of FIG. The AP broadcasts a beacon frame to all STAs, where the beacon frame carries the newly added fields, which are used to represent multiple data GI lengths that the AP supports. However, when the AP receives a beacon frame broadcast, the terminal analyzes a plurality of data GI lengths supported by the AP, and a data GI length that matches the data GI length supported by the terminal, This is because it is selected as the data GI length used for data communication between the terminal and the AP. Therefore, in the embodiment of the present invention, the data communication between the AP and the STA can be normally executed when there are a plurality of data GI lengths proposed in the HEW standard.

Referring to FIG. 2, FIG. 2 is a data communication method according to an embodiment of the present invention. As shown in FIG. 2, the data communication method of this embodiment includes steps S100 to S101.

S100. The access device constructs a beacon frame, the beacon frame includes a newly added field, and the newly added field represents a plurality of data guard interval lengths supported by the access device.

In a particular embodiment, the new generation standard solution HEW currently being studied by the standardization group supports a data GI length of {0.4us, 0.8us, 1.6us, 2.4us, 3.2us}, The access device is a wireless access point (AP). In the present invention, in order for the AP to better indicate the data GI length information, the newly added field is added to the beacon frame called "HE compatible GI" field, and the newly added field is supported by the AP. Used to represent multiple GI lengths. The “HE compatible GI” is used between the AP and the STA to exchange the data GI length supported by each of the AP and the STA. In the following, a detailed description will be provided individually in such aspects as the location of the "HE Enabled GI" field and the format of the "HE Enabled GI" field.

The “HE compatible GI” field can be placed at any position in the beacon frame. For example, the field may be placed in an existing element of the beacon frame or in a newly added element created in the beacon frame. Additionally, the field may be located in the SIG field of a Physical Layer Presentation Protocol Data Unit (PPDU) frame that carries the beacon frame. In the following, consider the case of creating a newly added element to arrange the "HE compatible GI" field. The newly created element is called an HE capability element. In this case, the “HE compatible GI” field may be arranged as follows.

In the first alternative implementation method, the "HE Capable GI" field is placed directly in the "HE Capability" element, and the "HE Capability" information element describes the selective capacity of the AP supporting the WLAN solution. Contains fields used for. The “HE compatible GI” field is arranged in the “HE capability” element, for example, and may be arranged in a manner as shown in FIG.

In the second alternative implementation method, the "HE enabled GI" field is placed in the field of the "HE Capability" element. As shown in FIG. 7, the “HE Capability” element includes a “HE Capability Information” field, which is used to indicate AP capability information. The “HE compatible GI” field may be arranged in the above “HE capability information” field.

In the present invention, a newly added field, that is, "HE compatible GI" field indicates the data GI length supported by the AP, and in the new generation standard HEW solution, the bandwidth supported by the AP is 20MHz, 40MHz, 80MHz. , Or 160 MHz. As shown in FIG. 8, there are multiple GI lengths at various bandwidths. The data GI length supported by the AP is N (N=1, 2, 3,..., 32)×0.4 us. The "HE compatible GI" field can be expressed by a plurality of methods. It should be noted that although some expression methods are separately used below as an example for explanation, the present specification is not limited to a particular expression method.

In the first alternative implementation method, the newly added field includes an indicator index value corresponding to each preset bandwidth, and the indicator index value is set by the access device within the preset bandwidth. It represents the minimum data guard interval length of all supported data guard interval lengths, and the preset bandwidth may include 20MHz, 40MHz, 80MHz, and 160MHz. For ease of explanation, a specific representation method is to randomly select M data GI lengths from all data GI lengths supported by various bandwidths shown in the table of FIG. 8 as GI lengths supported by AP. It may be a choice, which is shown in FIG. N is a serial number, and the value of N is {1, 2,. ． ． , M}, m represents the bit amount of the indicator bit, and N has a one-to-one correspondence with the value of the indicator bit. Assuming 6 data GI lengths are selected, M=6, N={1,2
,. ． ． , 6}, m=3, and the relationship between N and the instruction bit is as shown in FIG. For simplicity, assuming that the AP does not support some data GI length, a "-" indicates that the AP within the corresponding bandwidth does not support that GI length.

If the minimum data GI length supported by the AP is min_GI, the index value corresponding to min_GI is N, and various bandwidths correspond to one min_GI. FIG. 10 shows min_GI, which is supported by the AP in various bandwidths, and the relationship between the min_GI, the serial number, and the instruction bit, which are acquired by FIG.

The instruction index value included in the “HE compatible GI” field refers to an index value corresponding to min_GI indicated by the “HE compatible GI” field in various bandwidths. The index value corresponding to the min_GI indicated by the "HE Enabled GI" field in the various bandwidths refers to the serial number corresponding to the min_GI carried by the AP in each bandwidth and carried by the "HE Enabled GI" field. .. For example, the data GI length supported by the bandwidth of 20 MHz is {0.8us, 1.2us, 1.6us, 2.0us, 2.4us, 2.8us, 3.2us}. Assuming that the min_GI supported in the bandwidth of 20 MHz is 0.8 us, the indicator index value of the serial number of 20 MHz is 2. To process 40MHz, 80MHz, and 160MHz, refer to 20MHz processing. Specifically, the indicator index value of the “HE compatible GI” field in the beacon frame is represented in a binary-coded format, that is, in the format of the indicator bit, and a specific expression format is shown in FIG. 11, but here The “HE compatible GI” field includes an indication index value of each preset bandwidth, and the indication index value GI_Idx is represented by bit information. The specific bit information representation is shown in FIG.

In the second alternative implementation, the newly added field contains an indicator bit for each preset data guard interval length, which indicates whether the access device supports the preset data guard interval length. Used to indicate. In this implementation method, the influence of bandwidth is not taken into consideration, and M data GI lengths are selected as preset data GI lengths from the data GI lengths shown in FIG. For example, the preset data GI length is {0.4us, 0.8us, 1.2us, 1.6us, 2.0us, 2.4us, 2.8us, 3.2us}.

The "HE compliant GI" field uses an indication bit to indicate whether the AP supports the preset data GI length. The "HE compliant GI" field may use a single bit of the instruction bit to indicate each data GI length in all preset data GI lengths, and each bit information bit indicates one data GI length. FIG. 13 shows the expression method of the “HE compatible GI” field, and one bit indicates one data GI length. The specific bit information indication is shown in FIG.

In a third alternative implementation, the newly added field contains an indicator bit for each preset data guard interval length within each preset bandwidth, the indicator bit being preset by the access device. Used to indicate whether to support the preset data guard interval length within bandwidth. In this embodiment, as shown in FIG. 15, M data GI lengths are randomly selected from all the data GI lengths shown in FIG. 8 and are supported in various bandwidths as the data GI lengths supported by the AP. However, M=5 here. The "HE-enabled GI" field indicates the data GI length supported by each bandwidth. The "HE-enabled GI" field uses a single instruction bit to indicate the data GI length supported by the AP. That is, each bit separately indicates the data GI length supported by various bandwidths, and the representation format of the “HE compatible GI” field is shown in FIG. Specific bit information is shown in FIGS. 17A and 17B.

S101. In order that the terminal can perform data communication with the access device by selecting an available guard interval length from the beacon frame that matches the data guard interval length supported by the terminal, and using the available guard interval length, The access device broadcasts a beacon frame.

In particular embodiments, the access device broadcasts the constructed beacon frame, and the particular broadcasting method may encapsulate the beacon frame in a PPDU format for broadcasting. There may be multiple PPDU format encapsulation methods. For example, the beacon frame may be encapsulated in PPDU1 by existing standard 802.11ac, or by the new generation standard HEW so that terminals supporting the new generation standard HEW can identify and analyze PPDU2. Although another encapsulation method may be created to encapsulate the beacon frame in PPDU2, see the description of FIG. 3 for the specific creation method.

When the terminal STA1 supporting the 802.11ac standard and the terminal STA2 supporting the new generation standard HEW coexist within the broadcast range, the access device AP encapsulates the STA1 and STA2 so that both STA1 and STA2 can access the network. Broadcast PPDU1 and PPDU2. The method of broadcasting PPDU1 may be to broadcast PPDU1 during a specific period preset by an existing standard. A computation field may be added to PPDU1 to broadcast PPDU2, but the computation field may indicate the broadcast time of PPDU2 so that PPDU2 is broadcast at the time indicated by the computation field.

After receiving the beacon frame broadcast by the AP and encapsulating it in the PPDU1 format, STA1 accesses the network according to the existing 802.11ac standard. After detecting PPDU1 and/or PPDU2, STA2 analyzes the beacon frame, analyzes each capability element of the beacon frame, and analyzes the “HE compatible GI” field of the capability element to determine the data GI length supported by the AP. get. STA2 acquires the available data GI length used for communication with the AP by the data GI length supported by STA2, but the available data GI length matches the data GI length supported by STA2, And refer to the data GI length in the data GI length supported by AP. For example, the data GI length supported by STA2 is {0.8us, 1.6us, 2.4us, 3.2us}, and the data GI length supported by AP is {0.4us, 0.8us, 1.6us. , 2.0us, 2.4us, 3.2us}. The data GI length supported by both AP and STA2 is {0.8us, 1.6us, 2.4us, 3.2us}, and in this case {0.8us, 1.6us, 2.4us, 3.2us} is the usable data GI length. Subsequently, the STA2 performs data communication with the AP by using the selectable data GI length. Specifically, the STA2 selects the data GI length from the available GI length according to the channel condition, Data communication may be performed with the AP.

In this embodiment of the invention, the access device builds a beacon frame, the beacon frame including newly added fields, the newly added fields representing multiple data guard interval lengths supported by the access device. , The access device broadcasts the constructed beacon frame, and the terminal selects an available guard interval length that matches the data guard interval length supported by the terminal from the beacon frame broadcast by the access device and uses the available guard interval length. Communicate with the access device by using the interval length. In this embodiment, in the standard that proposes a plurality of data guard interval lengths, in order to normally execute data communication between an access device and a terminal, a plurality of data guard interval lengths supported by the access device are set in a beacon frame. May be encapsulated in the newly added field of.

Referring to FIG. 3, FIG. 3 is another data communication method according to an embodiment of the present invention. As shown in FIG. 3, the data communication method of this embodiment includes steps S200 to S202.

S200. The access device constructs a beacon frame, the beacon frame includes a newly added field, and the newly added field represents a plurality of data guard interval lengths supported by the access device.

S201. The access device separately encapsulates the beacon frame into a first standard protocol data unit and a second standard protocol data unit.

In a particular embodiment, consider the case where an STA supporting the first standard and an STA supporting the second standard coexist on the network. For example, STA1 supports the first standard and STA2 supports the second standard. The above first or second standard is a different WIFI solution, which may be an existing WIFI standard solution such as 802.11ac, or a new generation standard solution HEW currently being studied by the standardization group. Or another similar WIFI solution.

When encapsulating the beacon frame in the PPDU format, the access device AP has to encapsulate the beacon frame in two PPDU formats, a first standard protocol data unit PPDU1 and a second standard protocol data unit PPDU2, PPDU1 is obtained by encapsulation according to the first standard and PPDU2 is obtained by encapsulation according to the second standard. The specific encapsulation method will be described in detail below, but specifically includes steps S20 to S22.

S20. The access device acquires the maximum data guard interval length from the data guard interval lengths supported by the access device in the first standard, and determines the maximum data guard interval length as the first alternative data guard interval length.

In a particular embodiment, the AP separately supports a set of data GI lengths in the first and second standards. The first alternative data GI length refers to the maximum data GI length in the set of GIs supported by the AP in the first standard. For example, if the data GI length supported by the first standard AP is {0.4us, 0.8us}, the first alternative data GI length refers to the data GI length of 0.8us.

S21. The access device acquires the maximum data guard interval length from the data guard interval lengths supported by the access device in the second standard, and determines the maximum data guard interval length as the second alternative data guard interval length.

In certain embodiments, the AP also supports a second set of data GI lengths and the second alternative data guard interval length is the maximum data of a set of GIs that the AP supports in the second standard. See GI length. For example, if the set of data GI lengths supported by AP in the second standard is {0.4us, 0.8us, 1.6us, 2.4us, 3.2us}, the second alternative data GI length is , Refer to the data length of 3.2us.

STAs that support different standards are more diverse in the network, i.e., if there are multiple types of STAs, different types of STAs support different standards, but STAs that support different standards. It should be noted that there may be compatibility between. However, STA only has upward compatibility instead of backward compatibility. For example, a STA that supports HEW is compatible with a STA that supports the 802.11ac standard, but a STA that supports the 802.11ac standard is not compatible with a STA that supports HEW. For example, if there are multiple types of STAs on the network, the number of different standards supported by the various STAs in the network is 3, 4, or more, and the alternative data GI length is determined accordingly. May be done, in which case the number of alternative data GI lengths is correspondingly 3, 4 or more. For the sake of simplicity, assume that two STAs in the network each support a first standard (such as 802.11ac standard solution) and a second standard (such as the current HEW standard solution): The contents of the present invention will be described below, but the alternative data GI lengths are GI1 and GI2.

S22. The access device separately encapsulates the beacon frame into the first standard protocol data unit and the second standard protocol data unit according to the first alternative data guard interval length and the second alternative data guard interval length.

In a particular embodiment, the access device sends a beacon frame according to a first alternative data guard interval length GI1 and a second alternative data guard interval length GI2 to a first standard protocol data unit PPDU1 and a second standard protocol data unit. Although encapsulated in the unit PPDU2, the constructed PPDU1 and PPDU2 must conform to the PPDU format in each standard. The formats of PPDU1 and PPDU2 will be described separately below.

As shown in FIG. 18, optionally, the PPDU1 format includes preamble and bearer data, the bearer data includes beacon frames, and the preamble GI length and the data GI length in the PPDU1 format are GI1, respectively. The purpose of the AP sending PPDU1 is to make STA1 supporting the first standard network discoverable. The first standard may be the 802.11ac standard.

Optionally, the second standard may be the HEW standard. Referring to the HEW standard, the PPDU2 format has multiple design methods, but is not limited thereto. Below are three alternative PPDU2 format designs.

As shown in FIG. 19, in the first alternative implementation method, PPDU2 includes a legacy preamble, a high efficiency wireless local area network preamble, and bearer data, and a combination of L-STF, L-LTF and L-SIG. Is called a legacy preamble, and HE-SIG, HE-STF, and another possible combination of fields is called a HEW preamble. The GI length of the legacy preamble, the GI length of the HEW preamble, and the GI length of the bearer data are GI2, respectively. The purpose of the AP to send PPDU2 is to make the STA2 supporting the second standard network discoverable. STA2 can also detect PPDU1 and process PPDU1. A description of all fields in FIG. 19 is shown in FIG.

As shown in FIG. 21, in the second alternative implementation method, the PPDU2 format includes a legacy preamble, a high efficiency wireless local area network preamble, and bearer data, the GI length of the legacy preamble is GI1, and the HEW preamble is And the GI length of bearer data are GI2. The purpose of the AP to send PPDU2 is to make the STA2 supporting the second standard network discoverable. The length of the legacy preamble of the PPDU2 format in the first selective implementation method obtained from FIG. 20 is 80 us. The length of the legacy preamble in the PPDU2 format in the second alternative implementation method obtained from FIG. 22 is 20 us. In the second alternative implementation, the transmission overhead is reduced by 60 us when the remaining fields have the same length. A description of all fields in FIG. 21 is shown in FIG.

In a third alternative implementation method, the PPDU2 format is shown in FIG. 23, where PPDU2 contains the high efficiency wireless local area network preamble and bearer data. A description of all fields in FIG. 23 is shown in FIG. The GI length of the HEW preamble and the GI length of the bearer data are respectively GI2, and the purpose of the AP to send PPDU2 is to make STA2 supporting the second standard network discoverable. Compared to the PPDU format in the first alternative implementation method, the PPDU format in the third alternative implementation method removes the legacy preamble. Therefore, if the remaining fields have the same length, the transmission overhead is reduced by 80 us as compared to the PPDU format in the first alternative implementation method.

S202. The access device broadcasts a beacon frame encapsulated in a first standard protocol data unit and a beacon frame encapsulated in a second standard protocol data unit.

In a particular embodiment, the access device broadcasts a beacon frame encapsulated in PPDU1 and a beacon frame encapsulated in PPDU2, but the particular broadcasting method broadcasts PPDU1 in a preset period of time and It may be that PPDU2 is broadcast at the broadcast time of. However, it is necessary to add a calculation field indicating the transmission time of PPDU2 to PPDU1.

In this embodiment of the invention, the access device builds a beacon frame, the beacon frame including newly added fields, the newly added fields representing multiple data guard interval lengths supported by the access device. , The access device broadcasts the constructed beacon frame, and the terminal selects an available guard interval length that matches the data guard interval length supported by the terminal from the beacon frame broadcast by the access device and uses the available guard interval length. Communicate with the access device by using the interval length. In this embodiment, in the standard that proposes a plurality of data guard interval lengths, in order to normally execute data communication between an access device and a terminal, a plurality of data guard interval lengths supported by the access device are set in a beacon frame. May be encapsulated in the newly added field of.

Referring to FIG. 4, FIG. 4 is another data communication method according to an embodiment of the present invention. As shown in FIG. 4, the data communication method of this embodiment includes steps S300 to S304.

S300. The access device constructs a beacon frame, the beacon frame includes a newly added field, and the newly added field represents a plurality of data guard interval lengths supported by the access device.

S301. The access device separately encapsulates the beacon frame into a first standard protocol data unit and a second standard protocol data unit.

S302. The access device adds to the first standard protocol data unit a computed field used to indicate the time of transmission of the second standard protocol data unit.

In a particular embodiment, the AP sends the constructed PPDU1 and PPDU2. Assuming that PPDU1 is constructed according to the 802.11ac standard, the transmission period of PPDU1 defined by the 802.11ac standard is T1, and the transmission time of PPDU2 by the AP may be specified at random, and the AP is , PPDU1 and PPDU2 are alternately transmitted, for example. Computed fields may be added to PPDU1 for display, and computed fields may be added to PPDU2 for display. The calculation field is used to indicate the transmission time of PPDU2. The calculation field may indicate the transmission time of PPDU2 by a plurality of display methods, but only two methods are described below.

In the first alternative implementation method, the HE operation field uses only one bit to indicate whether the next m*T (eg, m=2/3) period has PPDU2, where , T is a preset period for broadcasting PPDU1. That is, when the value of the HE operation field is 1, it indicates that the next m*T period has PPDU2, and when the value of the HE operation field is 0, the next m*T period does not have PPDU2. Indicates that. As shown in FIG. 25, since the value of the HE calculation field of the first PPDU1 from the left is 1, it indicates that the next m*T period has PPDU2, and the value of the HE calculation field of the second PPDU1 is Since it is 0, it does not have PPDU2 in the next m*T period.

In the second alternative implementation method, the HE operation field has two or more bits shown as x bits. The HE operation field may be used to indicate whether the next (n+m*T) (eg, m=2/3, where n is a natural number indicated by x bits) period has PPDU2. That is, when the value of the HE calculation field is n, it indicates that the next (n+m*T) period has PPDU2. As shown in FIG. 26, since the value of the HE calculation field of the first PPDU1 from the left is 1, it indicates that the next m*T period has PPDU2, and the value of the HE calculation field of the second PPDU1 is 2, the next two m*T periods have PPDU2.

S303. The access device broadcasts a first standard protocol data unit containing a calculated field during a preset period.

In a particular embodiment, the access device broadcasts PPDU1 containing a computed field during a particular preset period. PPDU1 may be encapsulated by the 802.11ac standard, and thus PPDU1 may be broadcast by a preset period in the 802.11ac standard.

S304. The access device broadcasts the second standard protocol data unit at the transmission time indicated by the calculation field.

In a specific embodiment, as shown in FIG. 25 or FIG. 26, the access device broadcasts PPDU2 at the transmission time indicated by the calculation field. Upon receiving PPDU1, the terminal may know the transmission time of PPPDU2 by the calculation field, or may receive PPDU2 at the learned transmission time.

In this embodiment of the invention, the access device builds a beacon frame, the beacon frame including newly added fields, the newly added fields representing multiple data guard interval lengths supported by the access device. , The access device broadcasts the constructed beacon frame, and the terminal selects an available guard interval length that matches the data guard interval length supported by the terminal from the beacon frame broadcast by the access device and uses the available guard interval length. Communicate with the access device by using the interval length. In this embodiment, in the standard that proposes a plurality of data guard interval lengths, in order to normally execute data communication between an access device and a terminal, a plurality of data guard interval lengths supported by the access device are set in a beacon frame. May be encapsulated in the newly added field of.

Referring to FIG. 5, FIG. 5 is another data communication method according to an embodiment of the present invention. As shown in FIG. 5, the data communication method of this embodiment includes steps S400 to S402.

S400. The terminal acquires the beacon frame broadcast by the access device, and the beacon frame includes a newly added field, and the newly added field represents a plurality of data guard interval lengths supported by the access device.

In a particular embodiment, the terminal STA obtains the beacon frame broadcast by the access device, but the beacon frame may be a beacon frame, the beacon frame including the newly added fields and the newly added fields. The field represents a plurality of data GI lengths supported by the access device. The processing procedure of the STA corresponds to the processing procedure of the access device AP described above. On the AP side, the beacon frame is encapsulated in a first standard protocol data unit PPDU1 and a second standard protocol data unit PPDU2, the first standard may be the 802.11ac standard and the second standard may be It may be the HEW standard. In this embodiment, if STA1 supporting the first standard and STA2 supporting the second standard are present on the network, STA1 can perform normal detection processing only in PPDU1. The detection processing method is not detailed here, but refer to the 802.11ac standard solution. For the STA processing procedure described here, refer to the above-described STA2 processing procedure.

The AP transmits PPDU1 during a preset period, and PPDU1 includes a calculation field used to indicate the transmission time of PPDU2, and the calculation field indicates the transmission time of PPDU2. Specifically, the method used by the STA to obtain the beacon frame broadcast by the AP has three selective implementation methods.

In the first alternative implementation method, when the STA obtains the PPDU1 broadcast by the AP, the STA processes the PPDU1 and analyzes the beacon frame from the PPDU1, and at the same time, in the subsequent data communication between the STA and the AP. The preamble length is determined by the preamble of PPDU1. For example, when the preamble of PPDU1 is GI1, the STA sets GI1 as the preamble in the subsequent data communication.

In the second alternative implementation method, when the STA acquires the PPDU2 broadcast by the AP, the STA processes the PPDU2, and analyzes the beacon frame from the PPDU2, and at the same time, in the data communication between the STA and the AP thereafter. The preamble length is determined by the preamble of PPDU2. For example, when the preamble of PPDU2 is GI2, the STA sets GI2 as the preamble in the subsequent data communication.

In the third alternative implementation method, when the STA receives the PPDU1, the STA obtains the transmission time of the next PPDU2 from the PPDU1 by analyzing the “HE operation” field. For example, if the "HE operation" uses bits to indicate whether the next period has PPDU2, then if the "HE operation" field shows 0, the STA needs to detect PPDU2 in the next period. If there is, or if the "HE operation" field shows 1, it indicates that the STA does not need to detect PPDU2 in the next period. The STA analyzes the beacon frame from the detected PPDU2. Further, the STA determines the preamble length in the subsequent data communication between the STA and the AP by the preamble of PPDU2. For example, when the preamble of PPDU2 is GI2, the STA sets GI2 as the preamble in the subsequent data communication.

S401. The terminal selects an available guard interval length that matches the data guard interval length supported by the terminal from a plurality of data guard interval lengths supported by the access device.

In a particular embodiment, the terminal STA parses the beacon frame after obtaining the beacon frame. A specific analysis method is that the STA detects all capability elements of the beacon frame and obtains the data GI length supported by the AP by parsing the "HE enabled GI" field, and the STA supports the STA. The available GI length may be set based on the data GI length and the acquired data GI length supported by the AP. For example, if the data GI length indicated by the information on the "HE compatible GI" field is {0.8us, 1.6us, 2.4us}, the data GI length supported by the AP is {0.8us, 1.6us. , 2.4us}. The GI length supported by the STA itself is {0.4us, 0.8us, 1.6us, 2.4us, 3.2us}. The data GI length supported by both AP and STA2 is {0.8us, 1.6us}, and in this case, {0.8us, 1.6us} is the usable data GI length. In the subsequent communication between the STA and the AP, the data GI length is selected from the available data GI lengths according to the channel state to construct the PPDU.

S402. The terminal performs data communication with the access device by using the available guard interval length.

In certain embodiments, after obtaining the available data GI length, the STA may communicate data with the AP by using the available data GI length. Specifically, in the subsequent communication between the STA and the AP, the data GI length is selected from the available data GI lengths according to the channel state to construct the PPDU.

Further, the STA generates an association request frame with the available data GI length and sends the association request frame to the AP. After receiving the association request frame, the AP analyzes the association request frame and returns an association response frame to the STA if the STA is permitted to access the network. After receiving the association response frame, the STA analyzes the association response frame. In this case, the STA may establish an association with the AP, after which the AP and STA may perform data communication for data transmission.

In this embodiment of the invention, the access device builds a beacon frame, the beacon frame including newly added fields, the newly added fields representing multiple data guard interval lengths supported by the access device. , The access device broadcasts the constructed beacon frame, and the terminal selects an available guard interval length that matches the data guard interval length supported by the terminal from the beacon frame broadcast by the access device and uses the available guard frame length. Communicate with the access device by using the interval length. In this embodiment, in the standard that proposes a plurality of data guard interval lengths, in order to normally execute data communication between an access device and a terminal, a plurality of data guard interval lengths supported by the access device are set in a beacon frame. May be encapsulated in the newly added fields of

Referring to FIG. 27, FIG. 27 is a schematic structural diagram of an access device according to the present invention. As shown in FIG. 27, the access device according to the present embodiment includes a construction module 100, an encapsulation module 101, a processing module 102, and a transceiver module 103.

The building module 100 is configured to build a beacon frame, the beacon frame including newly added fields, where the newly added fields represent multiple data guard interval lengths supported by the access device. ..

In a particular embodiment, the new generation standard solution HEW currently being studied by the standardization group supports a data GI length of {0.4us, 0.8us, 1.6us, 2.4us, 3.2us}, The access device is a wireless access point (AP). In the present invention, in order for the AP to better indicate the data GI length information, the construction module 100 adds the newly added field to the beacon frame by calling it the “HE compatible GI” field, and the newly added field. Is used to represent multiple GI lengths supported by the AP. The “HE compatible GI” field is used for exchanging the data GI length supported by the AP and the STA, respectively, between the AP and the STA. In the following, a detailed description will be provided individually in such aspects as the location of the "HE Enabled GI" field and the format of the "HE Enabled GI" field.

The “HE compatible GI” field can be placed at any position in the beacon frame. For example, the field may be placed in an existing element of the beacon frame or in a newly added element created in the beacon frame. Additionally, the field may be located in the SIG field of a Physical Layer Presentation Protocol Data Unit (PPDU) frame that carries the beacon frame. In the following, consider the case of creating a newly added element to arrange the "HE compatible GI" field. The newly created element is called an HE capability element. In this case, the “HE compatible GI” field may be arranged as follows.

In the first alternative implementation method, the "HE Capable GI" field is placed directly in the "HE Capability" element, and the "HE Capability" information element describes the selective capacity of the AP supporting the WLAN solution. Contains fields used for. The “HE compatible GI” field is arranged in the “HE capability” element, for example, and may be arranged in a manner as shown in FIG.

In the second alternative implementation method, the "HE enabled GI" field is placed in the field of the "HE Capability" element. As shown in FIG. 7, the “HE Capability” element includes a “HE Capability Information” field, which is used to indicate AP capability information. The “HE compatible GI” field may be arranged in the above “HE capability information” field.

In the present invention, a newly added field, that is, “HE compatible GI” field indicates the data GI length supported by the AP, and in the new generation standard HEW solution, the bandwidth supported by the AP is 20 MHz, 40 MHz, 80 MHz. , Or 160 MHz. As shown in FIG. 8, there are multiple GI lengths at various bandwidths. The data GI length supported by the AP is N (N=1, 2, 3,..., 32)×0.4 us. The "HE compatible GI" field can be expressed by a plurality of methods. It should be noted that although some expression methods are separately used below as an example for explanation, the present specification is not limited to a particular expression method.

In the first alternative implementation method, the newly added field includes an indicator index value corresponding to each preset bandwidth, and the indicator index value is set by the access device within the preset bandwidth. It represents the minimum data guard interval length of all supported data guard interval lengths, and the preset bandwidth may include 20MHz, 40MHz, 80MHz, and 160MHz. For ease of explanation, a specific representation method is to randomly select M data GI lengths from all data GI lengths supported by various bandwidths shown in the table of FIG. 8 as GI lengths supported by AP. It may be a choice, which is shown in FIG. N is a serial number, and the value of N is {1, 2,. ． ． , M}, m represents the bit amount of the indicator bit, and N has a one-to-one correspondence with the value of the indicator bit. Assuming six data GI lengths are selected, M=6, N={1,2,. ． ． , 6}, m=3, and the relationship between N and the instruction bit is as shown in FIG. For simplicity, assuming that the AP does not support some data GI length, a "-" indicates that the AP within the corresponding bandwidth does not support that GI length.

If the minimum data GI length supported by the AP is min_GI, the index value corresponding to min_GI is N, and various bandwidths correspond to one min_GI. FIG. 10 shows min_GI, which is supported by the AP in various bandwidths, and the relationship between the min_GI, the serial number, and the instruction bit, which are acquired by FIG.

The instruction index value included in the “HE compatible GI” field refers to an index value corresponding to min_GI indicated by the “HE compatible GI” field in various bandwidths. The index value corresponding to the min_GI indicated by the “HE-enabled GI” field in various bandwidths refers to the serial number corresponding to the min_GI supported in each bandwidth and carried by the “HE-enabled GI” field. For example, the data GI length supported by the bandwidth of 20 MHz is {0.8us, 1.2us, 1.6us, 2.0us, 2.4us, 2.8us, 3.2us}. Assuming that the min_GI supported in the bandwidth of 20 MHz is 0.8 us, the indicator index value of the serial number of 20 MHz is 2. To process 40MHz, 80MHz, and 160MHz, refer to 20MHz processing. Specifically, "in the beacon frame
The indicator index value of the "HE compatible GI" field is represented in a binary-coded format, that is, in the format of the indicator bit, and a specific expression format is shown in Fig. 11. The indicating index value GI_Idx including the indicating index value of the preset bandwidth is represented by bit information. The specific bit information representation is shown in FIG.

In the second alternative implementation, the newly added field contains an indicator bit for each preset data guard interval length, which indicates whether the access device supports the preset data guard interval length. Used to indicate. In this implementation method, the influence of bandwidth is not taken into consideration, and M data GI lengths are selected as preset data GI lengths from the data GI lengths shown in FIG. For example, the preset data GI length is {0.4us, 0.8us, 1.2us, 1.6us, 2.0us, 2.4us, 2.8us, 3.2us}.

The "HE compliant GI" field uses an indication bit to indicate whether the AP supports the preset data GI length. The "HE compliant GI" field may use a single bit of the instruction bit to indicate each data GI length in all preset data GI lengths, and each bit information bit indicates one data GI length. FIG. 13 shows the expression method of the “HE compatible GI” field, and one bit indicates one data GI length. The specific bit information indication is shown in FIG.

In a third alternative implementation, the newly added field contains an indicator bit for each preset data guard interval length within each preset bandwidth, the indicator bit being preset by the access device. Used to indicate whether to support the preset data guard interval length within bandwidth. In this embodiment, as shown in FIG. 15, M data GI lengths are randomly selected from all the data GI lengths shown in FIG. 8 and are supported in various bandwidths as the data GI lengths supported by the AP. However, M=5 here. The "HE-enabled GI" field indicates the data GI length supported by each bandwidth. The "HE-enabled GI" field uses a single instruction bit to indicate the data GI length supported by the AP. That is, each bit separately indicates the data GI length supported by various bandwidths, and the representation format of the “HE compatible GI” field is shown in FIG. Specific bit information is shown in FIGS. 17A and 17B.

The transceiver module 103 is configured to broadcast the beacon frame and make data communication with the terminal.

In a particular embodiment, the transceiver module 103 of the access device broadcasts the constructed beacon frame and the particular broadcasting method may be encapsulating the beacon frame in a PPDU format for broadcasting. There may be multiple PPDU format encapsulation methods. For example, the beacon frame may be encapsulated in PPDU1 by existing standard 802.11ac, or by the new generation standard HEW so that terminals supporting the new generation standard HEW can identify and analyze PPDU2. Although another encapsulation method may be created to encapsulate the beacon frame in PPDU2, refer to the description of the subsequent embodiments for the specific creation method.

If the terminal STA1 supporting the 802.11ac standard and the terminal STA2 supporting the new generation standard HEW coexist within the broadcast range, the access device AP encapsulates the STA1 and STA2 so that both STA1 and STA2 can access the network. Broadcast PPDU1 and PPDU2. The method of broadcasting PPDU1 may be to broadcast PPDU1 during a specific period preset by an existing standard. A calculation field may be added to PPDU1 to broadcast PPDU2, but the calculation field may indicate the broadcast time of PPDU2 so that PPDU2 is broadcast at the time indicated by the calculation field.

After receiving the beacon frame broadcast by the AP and encapsulating it in the PPDU1 format, STA1 accesses the network according to the existing 802.11ac standard. After detecting PPDU1 and/or PPDU2, STA2 analyzes the beacon frame, analyzes each capability element of the beacon frame, and analyzes the “HE compatible GI” field of the capability element to determine the data GI length supported by the AP. get. STA2 acquires the available data GI length used for communication with the AP by the data GI length supported by STA2, but the available data GI length matches the data GI length supported by STA2, And refer to the data GI length in the data GI length supported by AP. For example, the data GI length supported by STA2 is {0.8us, 1.6us, 2.4us, 3.2us}, and the data GI length supported by AP is {0.4us, 0.8us, 1.6us. , 2.0us, 2.4us, 3.2us}. The data GI length supported by both AP and STA2 is {0.8us, 1.6us, 2.4us, 3.2us}, and in this case {0.8us, 1.6us, 2.4us, 3.2us} is the usable data GI length. Subsequently, the STA2 performs data communication with the AP by using the selectable data GI length. Specifically, the STA2 selects the data GI length from the available GI length according to the channel condition, Data communication may be performed with the AP.

Optionally, the access device may further include encapsulation module 101.

The encapsulation module 101 is configured to separately encapsulate the beacon frame into a first standard protocol data unit and a second standard protocol data unit.

In a particular embodiment, consider the case where an STA supporting the first standard and an STA supporting the second standard coexist on the network. For example, STA1 supports the first standard and STA2 supports the second standard. The first or second standard above is a different WIFI solution, which may be an existing WIFI standard solution such as 802.11ac, or a new generation standard solution HEW currently being considered by the standardization group. It could be, or another similar WIFI solution.

Upon encapsulating the beacon frame in PPDU format, the encapsulation module 101 of the access device AP encapsulates the beacon frame in two PPDU formats, a first standard protocol data unit PPDU1 and a second standard protocol data unit PPDU2. PPDU1 is obtained by encapsulation according to the first standard and PPDU2 is obtained by encapsulation according to the second standard. See the description of FIG. 28 for the specific encapsulation method.

The transceiver module 103 is specifically configured to broadcast a beacon frame encapsulated in a first standard protocol data unit and a beacon frame encapsulated in a second standard protocol data unit.

In a particular embodiment, the transceiver module 103 of the access device broadcasts a beacon frame encapsulated in PPDU1 and a beacon frame encapsulated in PPDU2, but the particular broadcast method is to broadcast PPDU1 in a preset time period. It may be broadcast and PPDU2 may be broadcast at a specific broadcast time. However, it is necessary to add a calculation field indicating the transmission time of PPDU2 to PPDU1.

Optionally, the access device can further include processing module 102.

The processing module 102 is configured to add to the first standard protocol data unit a calculated field used to indicate the time of transmission of the second standard protocol data unit.

In a particular embodiment, the AP sends the constructed PPDU1 and PPDU2. Assuming that PPDU1 is constructed according to the 802.11ac standard, the transmission period of PPDU1 defined by the 802.11ac standard is T1, and the transmission time of PPDU2 by the AP may be specified at random, and the AP is , PPDU1 and PPDU2 are alternately transmitted, for example. Processing module 102 may add computed fields to PPDU1 for display and computed fields to PPDU2 for display. The calculation field is used to indicate the transmission time of PPDU2. The calculation field may indicate the transmission time of PPDU2 by a plurality of display methods, but only two methods are described below.

In the first alternative implementation method, the HE operation field uses only one bit to indicate whether the next m*T (eg, m=2/3) period has PPDU2, where , T is a preset period for broadcasting PPDU1. That is, when the value of the HE operation field is 1, it indicates that the next m*T period has PPDU2, and when the value of the HE operation field is 0, the next m*T period does not have PPDU2. Indicates that. As shown in FIG. 25, since the value of the HE calculation field of the first PPDU1 from the left is 1, it indicates that the next m*T period has PPDU2, and the value of the HE calculation field of the second PPDU1 is Since it is 0, it does not have PPDU2 in the next m*T period.

In the second alternative implementation method, the HE operation field has two or more bits shown as x bits. The HE operation field may be used to indicate whether the next (n+m*T) (eg, m=2/3, where n is a natural number indicated by x bits) period has PPDU2. That is, when the value of the HE calculation field is n, it indicates that the next (n+m*T) period has PPDU2. As shown in FIG. 26, since the value of the HE calculation field of the first PPDU1 from the left is 1, it indicates that the next m*T period has PPDU2, and the value of the HE calculation field of the second PPDU1 is 2, the next two m*T periods have PPDU2.

The transceiver module 103 is specifically configured to broadcast a first standard protocol data unit including a math field for a preset period of time.

In a particular embodiment, the transceiver module 103 of the access device broadcasts PPDU1 containing the computed field during a particular preset period. PPDU1 may be encapsulated by the 802.11ac standard, and thus PPDU1 may be broadcast by a preset period in the 802.11ac standard.

The transceiver module 103 is further configured to broadcast the second standard protocol data unit at the transmission time indicated by the calculation field.

In a specific embodiment, as shown in FIG. 25 or FIG. 26, the transceiver module 103 of the access device broadcasts PPDU2 at the transmission time indicated by the computation field. Upon receiving PPDU1, the terminal may know the transmission time of PPPDU2 by the calculation field, or may receive PPDU2 at the learned transmission time.

In this embodiment of the invention, the access device builds a beacon frame, the beacon frame including newly added fields, the newly added fields representing multiple data guard interval lengths supported by the access device. , The access device broadcasts the constructed beacon frame, and the terminal selects an available guard interval length that matches the data guard interval length supported by the terminal from the beacon frame broadcast by the access device and uses the available guard interval length. Communicate with the access device by using the interval length. In this embodiment, in the standard that proposes a plurality of data guard interval lengths, in order to normally execute data communication between an access device and a terminal, a plurality of data guard interval lengths supported by the access device are set in a beacon frame. May be encapsulated in the newly added field of.

Referring to FIG. 28, FIG. 28 is a schematic structural diagram of an encapsulation module according to the present invention. As shown in FIG. 28, the encapsulation module of this embodiment includes a first acquisition unit 1030, a second acquisition unit 1031, and an encapsulation unit 1032.

The first acquisition unit 1030 acquires the maximum data guard interval length in the data guard interval lengths supported by the first standard access device, and determines the maximum data guard interval length as the first alternative data guard interval length. Is composed of.

In a particular embodiment, the AP separately supports a set of data GI lengths in the first and second standards. The first alternative data GI length refers to the maximum data GI length in the set of GIs supported by the AP in the first standard. For example, if the data GI length supported by the first standard AP is {0.4us, 0.8us}, the first alternative data GI length refers to the data GI length of 0.8us.

The second acquisition unit 1031 acquires the maximum data guard interval length in the data guard interval lengths supported by the second standard access device, and determines the maximum data guard interval length as the second alternative data guard interval length. Is composed of.

In certain embodiments, the AP also supports a second set of data GI lengths and the second alternative data guard interval length is the maximum data of a set of GIs that the AP supports in the second standard. See GI length. For example, if the set of data GI lengths supported by AP in the second standard is {0.4us, 0.8us, 1.6us, 2.4us, 3.2us}, the second alternative data GI length is , Refer to the data length of 3.2us.

STAs that support different standards are more diverse in the network, i.e., if there are multiple types of STAs, different types of STAs support different standards, but STAs that support different standards. It should be noted that there may be compatibility between. However, STA only has upward compatibility instead of backward compatibility. For example, a STA that supports HEW is compatible with a STA that supports the 802.11ac standard, but a STA that supports the 802.11ac standard is not compatible with a STA that supports HEW. For example, if there are multiple types of STAs on the network, the number of different standards supported by the various STAs in the network is 3, 4, or more, and the alternative data GI length is determined accordingly. May be done, in which case the number of alternative data GI lengths is correspondingly 3, 4 or more. For the sake of simplicity, assume that two STAs in the network each support a first standard (such as 802.11ac standard solution) and a second standard (such as the current HEW standard solution): The contents of the present invention will be described below. The alternative data GI lengths are GI1 and GI2.

The encapsulation unit 1032 separately encapsulates a beacon frame into a first standard protocol data unit and a second standard protocol data unit with a first alternative data guard interval length and a second alternative data guard interval length. Is configured as follows.

In a particular embodiment, the encapsulation unit 1032 of the access device sends the beacon frame to the first standard protocol data unit PPDU1 and the first alternative data guard interval length GI1 and the second alternative data guard interval length GI2. Although it is encapsulated in two standard protocol data units PPDU2, the constructed PPDU1 and PPDU2 must comply with the PPDU format in each standard. The formats of PPDU1 and PPDU2 will be described separately below.

As shown in FIG. 18, optionally, the PPDU1 format includes preamble and bearer data, the bearer data includes beacon frames, and the preamble GI length and the data GI length in the PPDU1 format are GI1, respectively. The purpose of the AP sending PPDU1 is to make STA1 supporting the first standard network discoverable. The first standard may be the 802.11ac standard.

Optionally, the second standard may be the HEW standard. Referring to the HEW standard, the PPDU2 format has multiple design methods, but is not limited thereto. Below are three alternative PPDU2 format designs.

As shown in FIG. 19, in the first alternative implementation method, PPDU2 includes a legacy preamble, a high efficiency wireless local area network preamble, and bearer data, and a combination of L-STF, L-LTF and L-SIG. Is called a legacy preamble, and HE-SIG, HE-STF, and another possible combination of fields is called a HEW preamble. The GI length of the legacy preamble, the GI length of the HEW preamble, and the GI length of the bearer data are GI2, respectively. The purpose of the AP to send PPDU2 is to make the STA2 supporting the second standard network discoverable. STA2 can also detect PPDU1 and process PPDU1. A description of all fields in FIG. 19 is shown in FIG.

As shown in FIG. 21, in the second alternative implementation method, the PPDU2 format includes a legacy preamble, a high efficiency wireless local area network preamble, and bearer data, the GI length of the legacy preamble is GI1, and the HEW preamble is And the GI length of bearer data are GI2. The purpose of the AP to send PPDU2 is to make the STA2 supporting the second standard network discoverable. The length of the legacy preamble of the PPDU2 format in the first selective implementation method obtained from FIG. 20 is 80 us. The length of the legacy preamble in the PPDU2 format in the second alternative implementation method obtained from FIG. 22 is 20 us. In the second alternative implementation, the transmission overhead is reduced by 60 us when the remaining fields have the same length. A description of all fields in FIG. 21 is shown in FIG.

In a third alternative implementation method, the PPDU2 format is shown in FIG. 23, where PPDU2 contains the high efficiency wireless local area network preamble and bearer data. A description of all fields in FIG. 23 is shown in FIG. The GI length of the HEW preamble and the GI length of the bearer data are respectively GI2, and the purpose of the AP to send PPDU2 is to make STA2 supporting the second standard network discoverable. Compared to the PPDU format in the first alternative implementation method, the PPDU format in the third alternative implementation method removes the legacy preamble. Therefore, if the remaining fields have the same length, the transmission overhead is reduced by 80 us as compared to the PPDU format in the first alternative implementation method.

In this embodiment of the invention, the access device builds a beacon frame, the beacon frame including newly added fields, the newly added fields representing multiple data guard interval lengths supported by the access device. , The access device broadcasts the constructed beacon frame, and the terminal selects an available guard interval length that matches the data guard interval length supported by the terminal from the beacon frame broadcast by the access device and uses the available guard interval length. Communicate with the access device by using the interval length. In this embodiment, in the standard that proposes a plurality of data guard interval lengths, in order to normally execute data communication between an access device and a terminal, a plurality of data guard interval lengths supported by the access device are set in a beacon frame. May be encapsulated in the newly added field of.

Referring to FIG. 29, FIG. 29 is a schematic block diagram of a terminal according to an embodiment of the present invention. As shown in FIG. 29, the terminal in this embodiment of the present invention includes a transceiver module 200 and a selection module 201.

The transceiver module 200 is configured to obtain a beacon frame broadcast by the access device, the beacon frame including a newly added field, the newly added field being a plurality of data supported by the access device. Indicates the guard interval length.

In a particular embodiment, the transceiver module 200 of the terminal STA obtains the beacon frame broadcast by the access device, but the beacon frame may be a beacon frame, the beacon frame including the newly added fields, The field added to indicates the multiple data GI lengths supported by the access device. The processing procedure of the STA corresponds to the processing procedure of the access device AP described above. On the AP side, the beacon frame is encapsulated in a first standard protocol data unit PPDU1 and a second standard protocol data unit PPDU2, the first standard may be the 802.11ac standard and the second standard may be It may be the HEW standard. In this embodiment, if STA1 supporting the first standard and STA2 supporting the second standard are present on the network, STA1 can perform normal detection processing only in PPDU1. The detection processing method is not detailed here, but refer to the 802.11ac standard solution. For the STA processing procedure described here, refer to the above-described STA2 processing procedure.

The AP transmits PPDU1 during a preset period, and PPDU1 includes a calculation field used to indicate the transmission time of PPDU2, and the calculation field indicates the transmission time of PPDU2. Specifically, the method used by the STA to obtain the beacon frame broadcast by the AP has three selective implementation methods.

Optionally, transceiver module 200 is specifically configured to obtain a first standard protocol data unit broadcast by the access device and parse a beacon frame from the first standard protocol data unit.

In the first alternative implementation method, when the STA obtains the PPDU1 broadcast by the AP, the STA processes the PPDU1 and analyzes the beacon frame from the PPDU1, and at the same time, in the subsequent data communication between the STA and the AP. The preamble length is determined by the preamble of PPDU1. For example, when the preamble of PPDU1 is GI1, the STA sets GI1 as the preamble in the subsequent data communication.

Optionally, transceiver module 200 is specifically configured to obtain a second standard protocol data unit broadcast by the access device and parse a beacon frame from the second standard protocol data unit.

In the second alternative implementation method, when the STA acquires the PPDU2 broadcast by the AP, the STA processes the PPDU2, and analyzes the beacon frame from the PPDU2, and at the same time, in the data communication between the STA and the AP thereafter. The preamble length is determined by the preamble of PPDU2. For example, when the preamble of PPDU2 is GI2, the STA sets GI2 as the preamble in the subsequent data communication.

Optionally, transceiver module 200 obtains a first standard protocol data unit broadcast by the access device and determines a time of transmission of the second standard protocol data unit from a calculated field in the first standard protocol data unit. Then, it is specifically configured to obtain the second standard protocol data unit according to the transmission time and analyze the beacon frame from the second standard protocol data unit.

In the third alternative implementation method, when the STA receives the PPDU1, the STA obtains the transmission time of the next PPDU2 from the PPDU1 by analyzing the “HE operation” field. For example, if the "HE operation" uses bits to indicate whether the next period has PPDU2, then if the "HE operation" field shows 0, the STA needs to detect PPDU2 in the next period. If there is, or if the "HE operation" field shows 1, it indicates that the STA does not need to detect PPDU2 in the next period. The STA analyzes the beacon frame from the detected PPDU2. Further, the STA determines the preamble length in the subsequent data communication between the STA and the AP by the preamble of PPDU2. For example, when the preamble of PPDU2 is GI2, the STA sets GI2 as the preamble in the subsequent data communication.

The selection module 201 is configured to select, from a plurality of data guard interval lengths supported by the access device, an available guard interval length that matches a data guard interval length supported by the terminal.

In a particular embodiment, the terminal STA parses the beacon frame after obtaining the beacon frame. A specific analysis method is that the STA detects all capability elements of the beacon frame and obtains the data GI length supported by the AP by analyzing the “HE compatible GI” field, and the STA selection module 201, The available GI length may be set based on the data GI length supported by the STA and the acquired data GI length supported by the AP. For example, if the data GI length indicated by the information on the “HE compatible GI” field is {0.8us, 1.6us, 2.4us}, the data GI length supported by the AP is {0.8us, 1.us. 6us, 2.4us}. The GI length supported by the STA itself is {0.4us, 0.8us, 1.6us, 2.4us, 3.2us}. The data GI length supported by both AP and STA2 is {0.8us, 1.6us}, and in this case, {0.8us, 1.6us} is the usable data GI length. In the subsequent communication between the STA and the AP, the data GI length is selected from the available data GI lengths according to the channel state to construct the PPDU.

The transceiver module 200 is further configured to communicate data with the access device using the available guard interval length.

In certain embodiments, after the STA obtains the available data GI length, the transceiver module 200 may communicate data with the AP by using the available data GI length. Specifically, in the subsequent communication between the STA and the AP, the data GI length is selected from the available data GI lengths according to the channel state to construct the PPDU.

Further, the STA generates an association request frame with the available data GI length and sends the association request frame to the AP. After receiving the association request frame, the AP analyzes the association request frame and returns an association response frame to the STA if the STA is permitted to access the network. After receiving the association response frame, the STA analyzes the association response frame. In this case, the STA may establish an association with the AP, after which the AP and STA may perform data communication for data transmission.

In this embodiment of the invention, the access device builds a beacon frame, the beacon frame including newly added fields, the newly added fields representing multiple data guard interval lengths supported by the access device. , The access device broadcasts the constructed beacon frame, and the terminal selects an available guard interval length that matches the data guard interval length supported by the terminal from the beacon frame broadcast by the access device and uses the available guard interval length. Communicate with the access device by using the interval length. In this embodiment, in the standard that proposes a plurality of data guard interval lengths, in order to normally execute data communication between an access device and a terminal, a plurality of data guard interval lengths supported by the access device are set in a beacon frame. May be encapsulated in the newly added field of.

Referring to FIG. 30, FIG. 30 is a schematic block diagram of another access device according to the present invention. The access device 30 of FIG. 30 may be configured to implement all the steps and methods in the method embodiments above. In the embodiment of FIG. 30, access device 30 includes processor 300, transceiver 301, memory 302, antenna 303, and bus 304. The processor 300 controls the operation of the access device 30, but may be configured to process signals. Memory 302 may include read-only memory and random access memory and provides instructions and data for processor 300. The transceiver 301 may be coupled to the antenna 303. Although all components of access device 30 are linked together by using bus system 304, bus system 304 further includes a power bus, control bus, and status signal bus in addition to a data bus. However, for the sake of clarity, the various buses are shown as bus system 304 in the figure. The access device 30 may be the AP shown in FIG. In the following, all components will be described in detail.

The processor is configured to construct a beacon frame, the beacon frame including a newly added field, the newly added field representing a plurality of data guard interval lengths supported by the access device.

The transceiver is configured to broadcast the beacon frame and to make data communication with the terminal.

Optionally, the new generation standard solution HEW currently being studied by the standardization group supports data GI lengths of {0.4us, 0.8us, 1.6us, 2.4us, 3.2us} and access The device is a wireless access point (AP). In the present invention, in order for the AP to better indicate the data GI length information, the newly added field is added to the beacon frame called "HE compatible GI" field, and the newly added field is supported by the AP. Used to represent multiple GI lengths. The “HE compatible GI” field is used for exchanging the data GI length supported by the AP and the STA, respectively, between the AP and the STA. In the following, a detailed description will be provided individually in such aspects as the location of the "HE Enabled GI" field and the format of the "HE Enabled GI" field.

The “HE compatible GI” field can be placed at any position in the beacon frame. For example, the field may be placed in an existing element of the beacon frame or in a newly added element created in the beacon frame. Additionally, the field may be located in the SIG field of a Physical Layer Presentation Protocol Data Unit (PPDU) frame that carries the beacon frame. In the following, consider the case of creating a newly added element to arrange the "HE compatible GI" field. The newly created element is called an HE capability element. In this case, the “HE compatible GI” field may be arranged as follows.

In the first alternative implementation method, the "HE Capable GI" field is placed directly in the "HE Capability" element, and the "HE Capability" information element describes the selective capacity of the AP supporting the WLAN solution. Contains fields used for. The “HE compatible GI” field is arranged in the “HE capability” element, for example, and may be arranged in a manner as shown in FIG.

In the second alternative implementation method, the "HE enabled GI" field is placed in the field of the "HE Capability" element. As shown in FIG. 7, the “HE Capability” element includes a “HE Capability Information” field, which is used to indicate AP capability information. The “HE compatible GI” field may be arranged in the above “HE capability information” field.

In the present invention, a newly added field, that is, “HE compatible GI” field indicates the data GI length supported by the AP, and in the new generation standard HEW solution, the bandwidth supported by the AP is 20 MHz, 40 MHz, 80 MHz. , Or 160 MHz. As shown in FIG. 8, there are multiple GI lengths at various bandwidths. The data GI length supported by the AP is N (N=1, 2, 3,..., 32)×0.4 us. The "HE compatible GI" field can be expressed by a plurality of methods. It should be noted that although some expression methods are separately used below as an example for explanation, the present specification is not limited to a particular expression method.

In the first alternative implementation method, the newly added field includes an indicator index value corresponding to each preset bandwidth, and the indicator index value is set by the access device within the preset bandwidth. It represents the minimum data guard interval length of all supported data guard interval lengths, and the preset bandwidth may include 20MHz, 40MHz, 80MHz, and 160MHz. For ease of explanation, a specific representation method is to randomly select M data GI lengths from all data GI lengths supported by various bandwidths shown in the table of FIG. 8 as GI lengths supported by AP. It may be a choice, which is shown in FIG. N is a serial number, and the value of N is {1, 2,. ． ． , M}, m represents the bit amount of the indicator bit, and N has a one-to-one correspondence with the value of the indicator bit. Assuming six data GI lengths are selected, M=6, N={1,2,. ． ． , 6}, m=3, and the relationship between N and the instruction bit is as shown in FIG. For simplicity, assuming that the AP does not support some data GI length, a "-" indicates that the AP within the corresponding bandwidth does not support that GI length.

If the minimum data GI length supported by the AP is min_GI, the index value corresponding to min_GI is N, and various bandwidths correspond to one min_GI. FIG. 10 shows min_GI, which is supported by the AP in various bandwidths, and the relationship between the min_GI, the serial number, and the instruction bit, which are acquired by FIG.

The instruction index value included in the “HE compatible GI” field refers to an index value corresponding to min_GI indicated by the “HE compatible GI” field in various bandwidths. The index value corresponding to the min_GI indicated by the “HE-enabled GI” field in various bandwidths refers to the serial number corresponding to the min_GI supported in each bandwidth and carried by the “HE-enabled GI” field. For example, the data GI length supported by the bandwidth of 20 MHz is {0.8us, 1.2us, 1.6us, 2.0us, 2.4us, 2.8us, 3.2us}. Assuming that the min_GI supported in the bandwidth of 20 MHz is 0.8 us, the indicator index value of the serial number of 20 MHz is 2. To process 40MHz, 80MHz, and 160MHz, refer to 20MHz processing. Specifically, the indicator index value of the “HE compatible GI” field in the beacon frame is represented in a binary-coded format, that is, in the format of the indicator bit, and a specific expression format is shown in FIG. 11, but here The “HE compatible GI” field includes an indication index value of each preset bandwidth, and the indication index value GI_Idx is represented by bit information. The specific bit information representation is shown in FIG.

In the second alternative implementation, the newly added field contains an indicator bit for each preset data guard interval length, which indicates whether the access device supports the preset data guard interval length. Used to indicate. In this implementation method, the influence of bandwidth is not taken into consideration, and M data GI lengths are selected as preset data GI lengths from the data GI lengths shown in FIG. For example, the preset data GI length is {0.4us, 0.8us, 1.2us, 1.6us, 2.0us, 2.4us, 2.8us, 3.2us}.

The "HE compliant GI" field uses an indication bit to indicate whether the AP supports the preset data GI length. The "HE compliant GI" field may use a single bit of the instruction bit to indicate each data GI length in all preset data GI lengths, and each bit information bit indicates one data GI length. FIG. 13 shows the expression method of the “HE compatible GI” field, and one bit indicates one data GI length. The specific bit information indication is shown in FIG.

In a third alternative implementation, the newly added field contains an indicator bit for each preset data guard interval length within each preset bandwidth, the indicator bit being preset by the access device. Used to indicate whether to support the preset data guard interval length within bandwidth. In this embodiment, as shown in FIG. 15, M data GI lengths are randomly selected from all the data GI lengths shown in FIG. 8 and are supported in various bandwidths as the data GI lengths supported by the AP. However, M=5 here. The "HE-enabled GI" field indicates the data GI length supported by each bandwidth. The "HE-enabled GI" field uses a single instruction bit to indicate the data GI length supported by the AP. That is, each bit separately indicates the data GI length supported by various bandwidths, and the representation format of the “HE compatible GI” field is shown in FIG. Specific bit information is shown in FIGS. 17A and 17B.

Optionally, the access device broadcasts the constructed beacon frame and the particular broadcasting method may be encapsulating the beacon frame in a PPDU format for broadcasting. There may be multiple PPDU format encapsulation methods. For example, the beacon frame may be encapsulated in PPDU1 by existing standard 802.11ac, or by the new generation standard HEW so that terminals supporting the new generation standard HEW can identify and analyze PPDU2. Although another encapsulation method may be created to encapsulate the beacon frame in PPDU2, see the description of FIG. 3 for the specific creation method.

If the terminal STA1 supporting the 802.11ac standard and the terminal STA2 supporting the new generation standard HEW coexist within the broadcast range, the access device AP encapsulates the STA1 and STA2 so that both STA1 and STA2 can access the network. Broadcast PPDU1 and PPDU2. The method of broadcasting PPDU1 may be to broadcast PPDU1 during a specific period preset by an existing standard. A calculation field may be added to PPDU1 to broadcast PPDU2, but the calculation field may indicate the broadcast time of PPDU2 so that PPDU2 is broadcast at the time indicated by the calculation field.

After receiving the beacon frame broadcast by the AP and encapsulating it in the PPDU1 format, STA1 accesses the network according to the existing 802.11ac standard. After detecting PPDU1 and/or PPDU2, STA2 analyzes the beacon frame, analyzes each capability element of the beacon frame, and analyzes the “HE compatible GI” field of the capability element to determine the data GI length supported by the AP. get. STA2 acquires the available data GI length used for communication with the AP by the data GI length supported by STA2, but the available data GI length matches the data GI length supported by STA2, And refer to the data GI length in the data GI length supported by AP. For example, the data GI length supported by STA2 is {0.8us, 1.6us, 2.4us, 3.2us}, and the data GI length supported by AP is {0.4us, 0.8us, 1.6us. , 2.0us, 2.4us, 3.2us}. The data GI length supported by both AP and STA2 is {0.8us, 1.6us, 2.4us, 3.2us}, and in this case {0.8us, 1.6us, 2.4us, 3.2us} is the usable data GI length. Subsequently, the STA2 performs data communication with the AP by using the selectable data GI length. Specifically, the STA2 selects the data GI length from the available GI length according to the channel condition, Data communication may be performed with the AP.

The processor is further configured to encapsulate the beacon frame into a first standard protocol data unit and a second standard protocol data unit.

The transceiver is further configured to broadcast the beacon frame encapsulated in the first standard protocol data unit and the beacon frame encapsulated in the second standard protocol data unit.

Optionally, consider the case where STAs supporting the first standard and STAs supporting the second standard coexist on the network. For example, STA1 supports the first standard and STA2 supports the second standard. The first or second standard above is a different WIFI solution, which may be an existing WIFI standard solution such as 802.11ac, or a new generation standard solution HEW currently being considered by the standardization group. It could be, or another similar WIFI solution.

When encapsulating the beacon frame in the PPDU format, the access device AP has to encapsulate the beacon frame in two PPDU formats, a first standard protocol data unit PPDU1 and a second standard protocol data unit PPDU2, PPDU1 is obtained by encapsulation according to the first standard and PPDU2 is obtained by encapsulation according to the second standard.

Optionally, the access device broadcasts a beacon frame encapsulated in PPDU1 and a beacon frame encapsulated in PPDU2, while a particular broadcasting method broadcasts PPDU1 during a preset period and It may be that PPDU2 is broadcast at the broadcast time. However, it is necessary to add a calculation field indicating the transmission time of PPDU2 to PPDU1.

The processor further obtains the maximum data guard interval length of the data guard interval lengths supported by the first standard access device and determines the maximum data guard interval length as the first alternative data guard interval length. Composed.

The processor further obtains the maximum data guard interval length in the data guard interval lengths supported by the second standard access device and determines the maximum data guard interval length as the second alternative data guard interval length. Composed.

The processor is further configured to separately encapsulate the beacon frame into the first standard protocol data unit and the second standard protocol data unit with the first alternative data guard interval length and the second alternative data guard interval length. Composed.

Optionally, the AP separately supports a set of data GI lengths in the first standard and the second standard. The first alternative data GI length refers to the maximum data GI length in the set of GIs supported by the AP in the first standard. For example, if the data GI length supported by the first standard AP is {0.4us, 0.8us}, the first alternative data GI length refers to the data GI length of 0.8us.

Optionally, the AP also supports a second standard set of data GI lengths, and the second alternative data guard interval length is a second set of GI maximum data supported by the second standard APs. See GI length. For example, if the set of data GI lengths supported by AP in the second standard is {0.4us, 0.8us, 1.6us, 2.4us, 3.2us}, the second alternative data GI length is , Refer to the data length of 3.2us.

STAs that support different standards are more diverse in the network, i.e., if there are multiple types of STAs, different types of STAs support different standards, but STAs that support different standards. It should be noted that there may be compatibility between. However, STA only has upward compatibility instead of backward compatibility. For example, a STA that supports HEW is compatible with a STA that supports the 802.11ac standard, but a STA that supports the 802.11ac standard is not compatible with a STA that supports HEW. For example, if there are multiple types of STAs on the network, the number of different standards supported by the various STAs in the network is 3, 4, or more, and the alternative data GI length is determined accordingly. May be done, in which case the number of alternative data GI lengths is correspondingly 3, 4 or more. For the sake of simplicity, assume that two STAs in the network each support a first standard (such as 802.11ac standard solution) and a second standard (such as the current HEW standard solution): The contents of the present invention will be described below. The alternative data GI lengths are GI1 and GI2.

Optionally, the access device sends a beacon frame with a first standard protocol data unit PPDU1 and a second standard protocol data unit with a first alternative data guard interval length GI1 and a second alternative data guard interval length GI2. Although encapsulated in PPDU2, the constructed PPDU1 and PPDU2 must comply with the PPDU format in each standard. The formats of PPDU1 and PPDU2 will be described separately below.

As shown in FIG. 18, optionally, the PPDU1 format includes preamble and bearer data, the bearer data includes beacon frames, and the preamble GI length and the data GI length in the PPDU1 format are GI1, respectively. The purpose of the AP sending PPDU1 is to make STA1 supporting the first standard network discoverable. The first standard may be the 802.11ac standard.

Optionally, the second standard may be the HEW standard. Referring to the HEW standard, the PPDU2 format has multiple design methods, but is not limited thereto. Below are three alternative PPDU2 format designs.

As shown in FIG. 19, in the first alternative implementation method, PPDU2 includes a legacy preamble, a high efficiency wireless local area network preamble, and bearer data, and a combination of L-STF, L-LTF and L-SIG. Is called a legacy preamble, and HE-SIG, HE-STF, and another possible combination of fields is called a HEW preamble. The GI length of the legacy preamble, the GI length of the HEW preamble, and the GI length of the bearer data are GI2, respectively. The purpose of the AP to send PPDU2 is to make the STA2 supporting the second standard network discoverable. STA2 can also detect PPDU1 and process PPDU1. A description of all fields in FIG. 19 is shown in FIG.

As shown in FIG. 21, in the second alternative implementation method, the PPDU2 format includes a legacy preamble, a high efficiency wireless local area network preamble, and bearer data, the GI length of the legacy preamble is GI1, and the HEW preamble is And the GI length of bearer data are GI2. The purpose of the AP to send PPDU2 is to make the STA2 supporting the second standard network discoverable. The length of the legacy preamble of the PPDU2 format in the first selective implementation method obtained from FIG. 20 is 80 us. The length of the legacy preamble in the PPDU2 format in the second alternative implementation method obtained from FIG. 22 is 20 us. In the second alternative implementation, the transmission overhead is reduced by 60 us when the remaining fields have the same length. A description of all fields in FIG. 21 is shown in FIG.

In a third alternative implementation method, the PPDU2 format is shown in FIG. 23, where PPDU2 contains the high efficiency wireless local area network preamble and bearer data. A description of all fields in FIG. 23 is shown in FIG. The GI length of the HEW preamble and the GI length of the bearer data are respectively GI2, and the purpose of the AP to send PPDU2 is to make STA2 supporting the second standard network discoverable. Compared to the PPDU format in the first alternative implementation method, the PPDU format in the third alternative implementation method removes the legacy preamble. Therefore, if the remaining fields have the same length, the transmission overhead is reduced by 80 us as compared to the PPDU format in the first alternative implementation method.

The processor is further configured to add to the first standard protocol data unit a calculation field used to indicate the time of transmission of the second standard protocol data unit.

The transceiver is further configured to broadcast the first standard protocol data unit including the math field for a preset period of time.

The transceiver is further configured to broadcast the second standard protocol data unit at the transmission time indicated by the computation field.

Optionally, the AP sends the constructed PPDU1 and PPDU2. Assuming that PPDU1 is constructed according to the 802.11ac standard, the transmission period of PPDU1 defined by the 802.11ac standard is T1, and the transmission time of PPDU2 by the AP may be specified at random, and the AP is , PPDU1 and PPDU2 are alternately transmitted, for example. Computed fields may be added to PPDU1 for display, and computed fields may be added to PPDU2 for display. The calculation field is used to indicate the transmission time of PPDU2. The calculation field may indicate the transmission time of PPDU2 by a plurality of display methods, but only two methods are described below.

In the first alternative implementation method, the HE operation field uses only one bit to indicate whether the next m*T (eg, m=2/3) period has PPDU2, where , T is a preset period for broadcasting PPDU1. That is, when the value of the HE operation field is 1, it indicates that the next m*T period has PPDU2, and when the value of the HE operation field is 0, the next m*T period does not have PPDU2. Indicates that. As shown in FIG. 25, since the value of the HE calculation field of the first PPDU1 from the left is 1, it indicates that the next m*T period has PPDU2, and the value of the HE calculation field of the second PPDU1 is Since it is 0, it does not have PPDU2 in the next m*T period.

In the second alternative implementation method, the HE operation field has two or more bits shown as x bits. The HE operation field may be used to indicate whether the next (n+m*T) (eg, m=2/3, where n is a natural number indicated by x bits) period has PPDU2. That is, when the value of the HE calculation field is n, the next (n+m*T) period is PPDU2.
It has a. As shown in FIG. 26, since the value of the HE calculation field of the first PPDU1 from the left is 1, it indicates that the next m*T period has PPDU2, and the value of the HE calculation field of the second PPDU1 is 2, the next two m*T periods have PPDU2.

Optionally, the access device broadcasts PPDU1 containing a computed field during a particular preset period. PPDU1 may be encapsulated by the 802.11ac standard, and thus PPDU1 may be broadcast by a preset period in the 802.11ac standard.

Optionally, as shown in FIG. 25 or FIG. 26, the access device broadcasts PPDU2 at the transmission time indicated by the calculation field. Upon receiving PPDU1, the terminal may know the transmission time of PPPDU2 by the calculation field, or may receive PPDU2 at the learned transmission time.

In this embodiment of the invention, the access device builds a beacon frame, the beacon frame including newly added fields, the newly added fields representing multiple data guard interval lengths supported by the access device. , The access device broadcasts the constructed beacon frame, and the terminal selects an available guard interval length that matches the data guard interval length supported by the terminal from the beacon frame broadcast by the access device and uses the available guard interval length. Communicate with the access device by using the interval length. In this embodiment, in the standard that proposes a plurality of data guard interval lengths, in order to normally execute data communication between an access device and a terminal, a plurality of data guard interval lengths supported by the access device are set in a beacon frame. May be encapsulated in the newly added field of.

Referring to FIG. 31, FIG. 31 is a schematic block diagram of another terminal according to the present invention. The terminal 40 of FIG. 31 may be configured to implement all the steps and methods in the method embodiments above. In the embodiment of FIG. 31, terminal 40 includes processor 400, transceiver 401, memory 402, antenna 403, and bus 404. The processor 400 controls the operation of the terminal 40, but can be configured to process signals. Memory 402 may include read-only memory and random access memory and provides instructions and data for processor 400. The transceiver 401 may be coupled to the antenna 403. The components within terminal 40 are coupled together by using bus system 404, which in addition to the data bus also includes a power supply bus, a control bus, and a status signal bus. However, for clarity of illustration, the various buses are shown as bus system 404 in the figure. For example, the terminal 40 may be STA1, STA2, and STA3 shown in FIG. In the following, all components of the terminal 40 will be described in detail.

The transceiver is configured to obtain a beacon frame broadcast by the access device, the beacon frame including a newly added field, the newly added field being a plurality of data guard intervals supported by the access device. Represents the length.

The processor is configured to select, from a plurality of data guard interval lengths supported by the access device, an available guard interval length that matches a data guard interval length supported by the terminal.

The transceiver is configured to communicate data with the access device by using the available guard interval length.

Optionally, the terminal STA obtains the beacon frame broadcast by the access device, the beacon frame may be a beacon frame, the beacon frame including the newly added field, and the newly added field. Represents a plurality of data GI lengths supported by the access device. The processing procedure of the STA corresponds to the processing procedure of the access device AP described above. On the AP side, the beacon frame is encapsulated in a first standard protocol data unit PPDU1 and a second standard protocol data unit PPDU2, the first standard may be the 802.11ac standard and the second standard may be It may be the HEW standard. In this embodiment, if STA1 supporting the first standard and STA2 supporting the second standard are present on the network, STA1 can perform normal detection processing only in PPDU1. The detection processing method is not detailed here, but refer to the 802.11ac standard solution. For the STA processing procedure described here, refer to the above-described STA2 processing procedure.

The AP transmits PPDU1 during a preset period, and PPDU1 includes a calculation field used to indicate the transmission time of PPDU2, and the calculation field indicates the transmission time of PPDU2. Specifically, the method used by the STA to obtain the beacon frame broadcast by the AP has three selective implementation methods.

In the first alternative implementation method, when the STA obtains the PPDU1 broadcast by the AP, the STA processes the PPDU1 and analyzes the beacon frame from the PPDU1, and at the same time, in the subsequent data communication between the STA and the AP. The preamble length is determined by the preamble of PPDU1. For example, when the preamble of PPDU1 is GI1, the STA sets GI1 as the preamble in the subsequent data communication.

In the second alternative implementation method, when the STA acquires the PPDU2 broadcast by the AP, the STA processes the PPDU2, and analyzes the beacon frame from the PPDU2, and at the same time, in the data communication between the STA and the AP thereafter. The preamble length is determined by the preamble of PPDU2. For example, when the preamble of PPDU2 is GI2, the STA sets GI2 as the preamble in the subsequent data communication.

In the third alternative implementation method, when the STA receives the PPDU1, the STA obtains the transmission time of the next PPDU2 from the PPDU1 by analyzing the “HE operation” field. For example, if the "HE operation" uses bits to indicate whether the next period has PPDU2, then if the "HE operation" field shows 0, the STA needs to detect PPDU2 in the next period. If there is, or if the "HE operation" field shows 1, it indicates that the STA does not need to detect PPDU2 in the next period. The STA analyzes the beacon frame from the detected PPDU2. Further, the STA determines the preamble length in the subsequent data communication between the STA and the AP by the preamble of PPDU2. For example, when the preamble of PPDU2 is GI2, the STA sets GI2 as the preamble in the subsequent data communication.

Optionally, the terminal STA parses the beacon frame after obtaining the beacon frame. A specific analysis method is that the STA detects all capability elements of the beacon frame and obtains the data GI length supported by the AP by parsing the "HE enabled GI" field, and the STA supports the STA. The available GI length may be set based on the data GI length and the acquired data GI length supported by the AP. For example, if the data GI length indicated by the information on the "HE compatible GI" field is {0.8us, 1.6us, 2.4us}, the data GI length supported by the AP is {0.8us, 1.6us. , 2.4us}. The GI length supported by the STA itself is {0.4us, 0.8us, 1.6us, 2.4us, 3.2us}. The data GI length supported by both AP and STA2 is {0.8us, 1.6us}, and in this case, {0.8us, 1.6us} is the usable data GI length. In the subsequent communication between the STA and the AP, the data GI length is selected from the available data GI lengths according to the channel state to construct the PPDU.

Optionally, after obtaining the available data GI length, the STA may be in data communication with the AP by using the available data GI length. Specifically, in the subsequent communication between the STA and the AP, the data GI length is selected from the available data GI lengths according to the channel state to construct the PPDU.

Further, the STA generates an association request frame with the available data GI length and sends the association request frame to the AP. After receiving the association request frame, the AP analyzes the association request frame and returns an association response frame to the STA if the STA is permitted to access the network. After receiving the association response frame, the STA analyzes the association response frame. In this case, the STA may establish an association with the AP, after which the AP and STA may perform data communication for data transmission.

The transceiver is further configured to obtain a first standard protocol data unit broadcast by the access device and parse a beacon frame from the first standard protocol data unit, or the transceiver is configured to receive a second standard protocol data unit broadcast by the access device. Or further configured to parse the beacon frame from the second standard protocol data unit and the transceiver acquires the first standard protocol data unit broadcast by the access device. The transmission time of the second standard protocol data unit is determined from the calculation field in the standard protocol data unit of 1, the second standard protocol data unit is acquired by the transmission time, and the beacon frame is transmitted from the second standard protocol data unit. Further configured to parse.

In this embodiment of the invention, the access device builds a beacon frame, the beacon frame including newly added fields, the newly added fields representing multiple data guard interval lengths supported by the access device. , The access device broadcasts the constructed beacon frame, and the terminal selects an available guard interval length that matches the data guard interval length supported by the terminal from the beacon frame broadcast by the access device and uses the available guard interval length. Communicate with the access device by using the interval length. In this embodiment, in the standard that proposes a plurality of data guard interval lengths, in order to normally execute data communication between an access device and a terminal, a plurality of data guard interval lengths supported by the access device are set in a beacon frame. May be encapsulated in the newly added field of.

A person of ordinary skill in the art may understand that all or a part of the processes of the method of the embodiments can be implemented by a computer program instructing relevant hardware. The program may be stored in a computer-readable storage medium. When the program is executed, the processes of the method of the embodiment are executed. Examples of the storage medium include a magnetic disk, an optical disk, a read-only memory (ROM), and a random access memory (RAM).

The above disclosure is merely exemplary embodiments of the present invention, and is not intended to limit the protection scope of the present invention. Therefore, equivalent modifications made based on the claims of the present invention shall be included in the scope of the present invention.

30 access device
40 terminals
100 building modules
101 encapsulation module
102 processing module
103 transceiver module
200 transceiver module
201 selection module
300 processors
301 transceiver
302 memory
303 antenna
304 bus, bus system
400 processors
401 transceiver
402 memory
403 antenna
404 bus, bus system
1030 1st acquisition unit
1031 Second acquisition unit
1032 encapsulation unit

Claims (28)

A data communication method,
Constructing a beacon frame by an access device, the beacon frame comprising a high efficiency (HE) capacity element, the HE capacity element comprising a field, the field comprising a plurality of guard interval lengths. Indicating whether each is supported by the access device, and
The access device broadcasting the beacon frame;
Performing data communication with the terminal using the available guard interval lengths supported by the access device and the terminal;
A data communication method including. The field comprises a plurality of indicator bits, one indicator bit of the plurality of indicator bits indicates whether the access device supports one guard interval length of the plurality of guard interval lengths. The method of claim 1 used to indicate. A value of the one indicator bit is 1 indicates that the access device supports the one guard interval length, a value of the one indicator bit is 0, the access device is the The method of claim 2, wherein the method does not support one guard interval length. After said step of constructing a beacon frame by the access device,
By the access device, further comprising the step of encapsulate the beacon frame on the first standard protocol data unit or the second standard protocol data units,
The step of the access device broadcasting the beacon frame,
The beacon frames, which are encapsulated in the encapsulated the beacon frame or the second standard protocol data unit to the first standard protocol data unit, comprising the step of said access device broadcasts from claim 1 The method according to any one of 3. The second standard protocol data unit comprises a legacy preamble, a high efficiency wireless local area network preamble, and bearer data, the bearer data comprising the beacon frame,
The method according to claim 4, wherein the guard interval length of the bearer data is a second alternative guard interval length supported by the access device of the second standard. 6. The method of claim 5, wherein the second alternative guard interval length is the maximum guard interval length supported by the access device of the second standard. 7. The method according to claim 6, wherein the second alternative guard interval length is 3.2 μs. The first standard protocol data unit comprises preamble and bearer data, the bearer data comprising the beacon frame,
The method according to claim 4 or 5, wherein the guard interval length of the preamble and the guard interval length of the bearer data are a first alternative guard interval length supported by the access device of the first standard. 9. The method of claim 8, wherein the first alternative guard interval length is a maximum guard interval length supported by the access device of the first standard. The method of claim 9, wherein the first alternative guard interval length is 0.8 μs. The step of a terminal obtaining a beacon frame broadcast by an access device, wherein the beacon frame comprises a high efficiency (HE) capacity element, the HE capacity element including a field, and the field comprising a plurality of Indicating whether each of the guard interval lengths of the is supported by the access device,
Selecting by the terminal an available guard interval length supported by the terminal and supported by the access device;
The terminal performing data communication with the access device by using the available guard interval length;
A data communication method including. The field comprises a plurality of indicator bits, one indicator bit of the plurality of indicator bits indicates whether the access device supports one guard interval length of the plurality of guard interval lengths. The method of claim 11, used to indicate. A value of the one indicator bit is 1 indicates that the access device supports the one guard interval length, a value of the one indicator bit is 0, the access device is the 13. The method according to claim 12, indicating that it does not support one guard interval length. The step of the terminal acquiring the beacon frame broadcast by the access device,
The terminal acquires the first standard protocol data unit broadcast by the access device, and analyzing the beacon frame from the first standard protocol data unit, or,
A step in which the terminal acquires a second standard protocol data unit broadcast by the access device and analyzes the beacon frame from the second standard protocol data unit ;
14. The method according to any one of claims 11 to 13 , comprising: An access device,
A processor,
A non-transitory computer readable storage medium coupled to the processor and storing program instructions for execution by the processor, the program instructions comprising:
Constructing a beacon frame, wherein the beacon frame comprises a high efficiency (HE) capacity element, the HE capacity element comprising a field, the field comprising a plurality of guard interval lengths. Constructing, indicating if supported by the access device,
A non-transitory computer-readable storage medium for instructing
A transceiver configured to broadcast the beacon frame and perform data communication with a terminal,
Including an access device. The field comprises a plurality of indicator bits, one indicator bit of the plurality of indicator bits indicates whether the access device supports one guard interval length of the plurality of guard interval lengths. The access device according to claim 15, which is used for indicating. A value of the one indicator bit is 1 indicates that the access device supports the one guard interval length, a value of the one indicator bit is 0, the access device is the The access device according to claim 16, indicating that it does not support one guard interval length. Wherein the processor, the first standard protocol data unit a beacon frame or a second encapsulation to the transceiver in the standard protocol data unit, the beacon frame or the first encapsulated in the first standard protocol data units 2 is further configured to broadcast a standard protocol the beacon frames, which are encapsulated in the data unit, access device according to any one of claims 15 to 17. The second standard protocol data unit comprises a legacy preamble, a high efficiency wireless local area network preamble, and bearer data, the bearer data comprising the beacon frame,
The bearer data guard interval length is a second alternative guard interval length supported by the access device of the second standard,
The access device according to claim 18. 20. The access device according to claim 19, wherein the second alternative guard interval length is a maximum guard interval length supported by the access device of the second standard. The access device according to claim 20, wherein the second alternative guard interval length is 3.2 μs. The first standard protocol data unit comprises preamble and bearer data, the bearer data comprising the beacon frame,
The access device according to claim 18 or 19, wherein the guard interval length of the preamble and the guard interval length of the bearer data are a first alternative guard interval length supported by the access device of the first standard. .. 23. The access device of claim 22, wherein the first alternative guard interval length is a maximum guard interval length supported by the access device of the first standard. 24. The access device according to claim 23, wherein the first alternative guard interval length is 0.8 μs. A terminal,
A processor,
A non-transitory computer readable storage medium coupled to the processor and storing program instructions for execution by the processor, the program instructions comprising:
Selecting an available guard interval length supported by the terminal and supported by the access device from a plurality of data guard interval lengths supported by the access device,
A non-transitory computer-readable storage medium for instructing
A transceiver configured to obtain a beacon frame broadcast by the access device, the beacon frame comprising a high efficiency (HE) capacity element, the HE capacity element comprising a field, A field, a transceiver indicating whether each of a plurality of guard interval lengths is supported by the access device;
Including
The transceiver is further configured to communicate data with the access device by using the available guard interval length,
Terminal. The field comprises a plurality of indicator bits, one indicator bit of the plurality of indicator bits indicates whether the access device supports one guard interval length of the plurality of guard interval lengths. The terminal according to claim 25 , which is used for indicating. A value of the one indicator bit is 1 indicates that the access device supports the one guard interval length, a value of the one indicator bit is 0, the access device is the 27. The terminal according to claim 26 , indicating that it does not support one guard interval length. Said transceiver, said access device obtains the first standard protocol data units broadcast and consists to analyze the beacon frame from the first standard protocol data units, or,
Said transceiver, said access device obtains the second standard protocol data units broadcast and consists to analyze the beacon frame from the second standard protocol data units,請 Motomeko 26 or 27 The terminal described in.

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