CN104066148B - Service discovery method, access point and website - Google Patents

Abstract

The embodiment of the present invention relates to a service discovery method, an access point and a station. The method includes: classifying each service information according to its content to obtain different service information groups; determining the broadcast time of each service information group, And establish a service directory according to the broadcast time and information identification of the service information group; add the service information group and the service directory to the broadcast frame; determine the broadcast cycle of the broadcast frame, and periodically send the broadcast frame to the station, so that the station can learn from the broadcast frame Find the service information required by itself in the service information group or learn the broadcast time of the service information group in which the service information required by itself is located from the service directory of the broadcast frame. Therefore, the present invention realizes the use of the AP to classify all service information and send it to the STA, and the STA receives the required service information at the moment of learning, without receiving all the service information, reduces the power consumption of the STA, and can support large data Amount of passive service discovery.

Description

Service Discovery Methods, Access Points, and Sites

technical field

The present invention relates to the field of communication technology, in particular to a service discovery method, access point and station.

Background technique

With the development of communication technology, the wireless local area network (Wireless Local Area Network, WLAN) usually adopts the service discovery based on the access point (Access Point, AP), that is, the station (station, STA) needs to establish a communication link with the AP first. After the road, you will know what services the AP can provide.

Currently, service discovery methods can be divided into two types: active service discovery and passive service discovery. The method of actively discovering services means that the STA actively sends a service request to the service device, and if the service device can provide the service required by the STA, it will reply a service response to the STA. The way of passive service discovery means that the STA waits for and receives the service information broadcast by the service device, and discovers the service information it needs from it.

Among them, the process of passive service discovery is: the AP broadcasts the service information in a broadcast frame, for example, broadcasts through a beacon (Beacon), and the STA discovers the desired service information by receiving the broadcast frame.

However, in some scenarios, there are many types of services and a large amount of data. If the AP broadcasts all service information in one beacon (Beacon), it will cause a high channel occupancy rate in a certain period of time. Assuming that more than one AP is broadcasting information at the same time, it is likely to cause information collisions. Once If a collision occurs, all service information will be lost, and we can only wait for the next Beacon. For the STA, it needs to be in the monitoring state all the time to receive the detailed information of all types of services in the broadcast frame, but in fact most of them are not what it needs, and cause high power consumption on the STA side.

Contents of the invention

The present invention provides a service discovery method, access point, and station to solve the problem that in the prior art, in the scenario where there are many service types and a large amount of data, the AP broadcasts all service information in one beacon, and the STA needs It is always in the monitoring state and receives a lot of unnecessary information, which leads to the problem of high power consumption on the STA side. The AP is used to classify all service information and send it to the STA, and the STA receives the required service information at the moment of learning, while It does not need to receive all service information, reduces the power consumption of STA, and can support passive service discovery with a large amount of data.

In the first aspect, the present invention provides a service discovery method, the method comprising: the access point classifies each service information according to its content to obtain different service information groups, and each service information group has an information identifier , the content of the service information in each service information group belongs to the service type corresponding to the information identifier; the access point determines the broadcast time of each service information group, and according to the broadcast of the service information group time and information identification to establish a service directory, the service directory includes broadcast time and information identification of all service information groups; the access point adds the service information group and the service directory to the broadcast frame; the access The point determines the broadcast period of the broadcast frame, and periodically sends the broadcast frame to the station according to the broadcast period, so that the station can find the service information it needs from the service information group of the broadcast frame or obtain the service information from the broadcast frame. The broadcast time of the service information group in which the service information required by the self is obtained from the service catalog of the broadcast frame.

In a first possible implementation manner, the service catalog further includes summary information of service information in each service information group, and adding the service information group and the service catalog to a broadcast frame, including: adding the service information groups to each broadcast frame, and adding the service catalog to each broadcast frame, so that the service information groups carried by each broadcast frame are different, and each The service catalogs carried by broadcast frames are all the same, wherein each broadcast frame carries a service catalog and a type of service information group.

In a second possible implementation manner, the determining the broadcast time of each service information group, and establishing a service directory according to the broadcast time and information identifier of the service information group, further includes: The broadcast time of the field determines the broadcast time of the service catalog.

With reference to the second possible implementation manner of the first aspect, in a third possible implementation manner, the broadcast frame includes: a first broadcast frame and a second broadcast frame; combining the service information group and the Adding the service directory to the broadcast frame includes: adding the service directory to the first broadcast frame, and adding the broadcast time of the service directory and the service information group to different second broadcast frames, so that each The service information groups carried in the second broadcast frame are all different.

In a second aspect, the present invention provides a method for service discovery, the method comprising: a station receiving a broadcast frame carrying a service catalog and a service information group sent by an access point, the service catalog including information identifiers of service information and service The broadcast time of the information group; discover the service information required by itself from the service information group of the broadcast frame or learn the broadcast time of the service information group in which the service information required by itself is located in the service directory of the broadcast frame .

In a first possible implementation manner, the discovering the service information required by itself from the service information group of the broadcast frame or learning the location of the service information required by itself from the service directory of the broadcast frame The broadcast time of the service information group includes: when the service information group of the received broadcast frame contains the service information required by itself, the station stops receiving other information sent by the access point broadcast frame; when the service information group of the received broadcast frame does not contain the service information required by itself, then the station learns from the service directory where the service information required by itself is located After the broadcast time of the service information group, enter the dormant state, enter the receiving state at the broadcast time of the service information group where the service information required by itself is located, and find the service information required by itself from the received broadcast frame .

In a second possible implementation manner, the discovering the service information required by itself from the service information group of the broadcast frame or obtaining the service information required by itself from the service directory of the broadcast frame The broadcast time of the service information group includes: when the service information group of the received broadcast frame contains the service information required by itself, the station no longer receives other information sent by the access point service information, and discard other broadcast frames sent by the access point; when the service information group of the received broadcast frame does not contain the service information required by itself, and the service list If there is an information identifier of the service information corresponding to the service information required by itself and the broadcast time of the service information group, then the broadcast frame is received at the broadcast time of the service information group, and the received The service information required by the self is found in the broadcast frame, and other broadcast frames sent by the access point are discarded; when the service information group of the received broadcast frame does not contain the service information required by the self service information, and there is no information identification of the service information and broadcast time of the service information group corresponding to the service information required by the station in the service directory, then the station no longer receives the access The service information sent by the access point is discarded for other broadcast frames sent by the access point.

In a third possible implementation manner, the broadcast frame includes a first broadcast frame and a second broadcast frame, and receiving, by the station, a broadcast frame carrying a service information group and a service catalog sent by an access point, includes: receiving the The first broadcast frame carrying the service catalog sent by the access point, and receiving the second broadcast frame carrying the broadcast time of the service catalog and the service information group, wherein the service information group carried by each second broadcast frame All are different.

In a third aspect, the present invention provides an access point, which includes: a classification unit for classifying each service information according to its content to obtain different service information groups, each service information The group has a summary information identifying each service information, the content of the service information in each service information group belongs to the service type corresponding to the information identification, and transmits the service information group to the processing unit; the processing unit , used to receive the service information group from the classification unit, determine the broadcast time of each service information group, and establish a service directory according to the broadcast time and information identification of the service information group, and the service directory includes all The broadcast time and information identification of the service information group, and transmitting the service information group and the service directory to the adding unit; the adding unit is used to receive the service information group and the service directory from the processing unit, and The service information group and the service catalog are added to the broadcast frame, and the broadcast frame is transmitted to the sending unit; the sending unit is used to receive the broadcast frame from the adding unit, determine the broadcast period of the broadcast frame, And periodically send the broadcast frame to the station according to the broadcast period, so that the station can find the service information it needs from the service information group of the broadcast frame or learn the service information from the service list of the broadcast frame. The broadcast time of the service information group in which the service information required by itself is located.

In a first possible implementation manner, the service directory further includes summary information of service information in each service information group, and the adding unit is configured to respectively add the service information group to each broadcast frame , and add the service list to each broadcast frame, so that the service information groups carried by each broadcast frame are different, and the service lists carried by each broadcast frame are all the same, wherein each A broadcast frame carries a service directory and a type of service information set.

In a second possible implementation manner, the service catalog further includes summary information of the service information in each service information group, and the processing unit is further configured to determine according to the broadcast time of each service information group The broadcast time of the service catalog.

With reference to the second possible implementation of the third aspect, in a third possible implementation, the broadcast frame includes: a first broadcast frame and a second broadcast frame; the adding unit is configured to add the service directory added to the first broadcast frame, and the broadcast time of the service list and the service information group are added to different second broadcast frames, so that the service information groups carried by each second broadcast frame are different.

In a fourth aspect, the present invention provides a station, the station includes: a receiving unit, configured to receive a broadcast frame carrying a service catalog and a service information group sent by an access point, the service catalog including information identifiers of service information and the broadcast time of the service information group, and transmit the broadcast frame to the discovery unit; the discovery unit is used to receive the broadcast frame from the receiving unit, and discover the required information from the service information group of the broadcast frame The service information or the broadcast time of the service information group in which the service information required by itself is obtained from the service catalog of the broadcast frame.

In a first possible implementation manner, the discovery unit is configured to, when the service information group of the received broadcast frame contains the service information required by itself, the station stops receiving the Other broadcast frames sent by the access point; when the service information group of the received broadcast frame does not contain the service information required by itself, the station learns the service information from the service directory After the broadcast time of the service information group where the service information required by itself enters the dormant state, enters the receiving state at the broadcast time of the service information group where the service information required by itself is located, and finds all Describe the service information you need.

In a second possible implementation manner, the discovery unit is configured to: when the service information group of the received broadcast frame contains the service information required by itself, the station no longer receives the other service information sent by the access point, and discard other broadcast frames sent by the access point; when the service information group of the received broadcast frame does not contain the service required by itself information, and there is an information identifier of the service information corresponding to the service information required by the service directory and a broadcast time of the service information group in the service directory, then receiving the broadcast frame at the broadcast time of the service information group, And discover the service information required by the self from the received broadcast frame, and discard other broadcast frames sent by the access point; when the service information group of the received broadcast frame does not contain the service information required by itself, and there is no information identifier of the service information and broadcast time of the service information group corresponding to the service information required by itself in the service directory, then the site The service information sent by the access point is no longer received, and other broadcast frames sent by the access point are discarded.

In a third possible implementation manner, the broadcast frame includes a first broadcast frame and a second broadcast frame, and the receiving unit is configured to receive the first broadcast frame carrying the service catalog sent by the access point, and receiving the second broadcast frame carrying the broadcast time of the service list and the service information group, wherein the service information groups carried by each second broadcast frame are different.

By applying the service discovery method, access point and station disclosed in the present invention, the access point classifies the service information according to different service information groups according to the summary information of each service information, and the service information in each service information group belongs to the same service type, determine the broadcast time of each service information group, and establish a service directory according to the broadcast time and information identification of the service information group, the service directory includes the broadcast time and information identification of all service information groups, and combine the service information group and all service information groups The service catalog is added to the broadcast frame, and the broadcast frame is sent to the station. After the station receives the broadcast frame carrying the service catalog and service information group sent by the access point, according to the service catalog and the service information group carried by the broadcast frame, The service information group discovers the service information required by itself, realizes the use of the AP to classify all service information and send it to the STA, and the STA receives the required service information at the moment of learning, without receiving all the service information, reducing the STA The power consumption can support the passive service discovery of a large amount of data.

Description of drawings

FIG. 1 is a flowchart of a service discovery method provided by Embodiment 1 of the present invention;

FIG. 2 is a schematic diagram of an access point sending a broadcast frame to a station according to Embodiment 2 of the present invention;

FIG. 3 is a flowchart of a service discovery method provided in Embodiment 3 of the present invention;

FIG. 4 is a flowchart of a service discovery method provided in Embodiment 4 of the present invention;

FIG. 5 is a schematic diagram of an access point sending a broadcast frame to a station according to Embodiment 5 of the present invention;

FIG. 6 is a schematic diagram of an access point sending a broadcast frame to a station according to Embodiment 6 of the present invention;

FIG. 7 is a flowchart of a service discovery method provided by Embodiment 7 of the present invention;

FIG. 8 is a schematic diagram of an access point provided in Embodiment 8 of the present invention;

FIG. 9 is a schematic diagram of a site provided by Embodiment 9 of the present invention;

FIG. 10 is a schematic diagram of an access point provided in Embodiment 10 of the present invention;

FIG. 11 is a schematic diagram of a site provided by Embodiment 11 of the present invention.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

In the service discovery method, access point and station provided by the embodiments of the present invention, the access point is used for the station to discover the service information it needs from the service information group of the broadcast frame or from the service list of the broadcast frame Know the broadcast time of the service information group where the service information required by itself is located, determine the broadcast time of each service information group, and combine the summary information of each service information and the broadcast time of each service information group Time composes the service catalog, adds the service information group and the service catalog to the broadcast frame, and sends the broadcast frame to the station, after the station receives the broadcast frame carrying the service catalog and the service information group sent by the access point According to the service catalog and service information group carried by the broadcast frame, the service information required by itself is discovered, and the AP is used to classify all the service information and send it to the STA, and the STA receives the required service information at the moment of learning , without receiving all service information, reducing the power consumption of the STA, and supporting passive service discovery with a large amount of data.

Wherein, the passive discovery service method involved in all embodiments of the present invention refers to: the access point AP sends a broadcast frame to the station STA, for example, the broadcast frame is a beacon Beacon, and the station STA waits for and receives the broadcast frame of the access point AP. The broadcast frame sent, from which the service information required by itself can be found. Wherein, a beacon (Beacon) is a kind of management frame stipulated in the 802.11 standard, which is periodically broadcast and sent by the AP.

FIG. 1 is a flowchart of a service discovery method provided by Embodiment 1 of the present invention. As shown in the figure, the embodiment of the present invention specifically includes the following steps:

Step 110, the access point classifies each service information according to its content to obtain different service information groups, each service information group has an information identifier, and the service information in the content of each service information group belongs to the information identifier. corresponding service type. Wherein, the content of the service information refers to the detailed content of the service information, and the summary information of the service information refers to the simple content of the service information.

Specifically, the service information of the access point is provided by one or more STAs, and the STAs report the service information to the AP for AP stations and non-AP stations, that is, one or more AP stations and non-AP stations that provide services. The access point classifies all collected service information according to the summary information of each service information. For example, classify coffee shops, various restaurants, food supermarkets, etc. into the catering category. Wherein, the abstract information of each service information refers to the simple information of the service information, according to which service type the service information belongs to can be identified, and part of the detailed content of the service information can also be known according to the simple information. For example, the access point classifies all the service information to obtain three service information groups: a catering service information group, an entertainment service information group, and a traffic service information group. Among them, the information identifier of the catering service information group is catering; the information identifier of the entertainment service information group is entertainment; the information identifier of the transportation service information group is traffic.

In addition, each service information group includes the detailed content of all service information of the service type corresponding to its information identifier. details.

Step 120, the access point determines the broadcast time of each service information group, and establishes a service directory according to the broadcast time and information identifiers of the service information groups, and the service directory includes the broadcast times and information identifiers of all service information groups.

Specifically, the broadcast time of each service information group, for example, three service information groups: the catering service information group, the entertainment service information group, and the transportation service information group, determine the time of these three service information groups broadcast time. The information identification of the catering service information group is catering; the information identification of the entertainment service information group is entertainment; the information identification of the transportation service information group is traffic. A service directory is established according to the broadcast time and information identifiers of the three service information groups.

In addition, the service catalog may also include summary information of service information in each service information group. Therefore, the service directory includes not only the information identification of all service information groups, but also the simple information of all service information provided by the access point AP, that is, the summary information of the service information in each service information group, and the corresponding service information group The broadcast time is the exact time when the detailed content of each service information included in the service information group is broadcast. For example, the catering service information group is sent after the first beacon period.

Step 130, the access point adds the service information group and the service list to the broadcast frame.

Step 140, the access point determines the broadcast period of the broadcast frame, and periodically sends the broadcast frame to the station according to the broadcast period, so that the station can find the service information it needs from the service information group of the broadcast frame or from the service list of the broadcast frame Obtain the broadcast time of the service information group in which the service information required by itself is located.

In one embodiment, the service directory in step 130 further includes summary information of the service information in each service information group, and the access point adds the service information group to each broadcast frame, and adds the service directory to the In each broadcast frame, the service information group carried by each broadcast frame is different, and the service list carried by each broadcast frame is the same.

Specifically, each broadcast frame carries a service directory and a type of service information group. Among them, the types of service information groups carried by each broadcast frame are different. For example, if the first broadcast frame carries a service catalog and a service information group related to catering, the second broadcast frame contains a service catalog and entertainment Related to a service information group, the third broadcast frame contains a service directory and a service information group related to the transportation mode. Wherein, the service catalogs included in all broadcast frames are the same.

In one embodiment, in step 140, each broadcast frame carries a service directory and a type of service information group.

Specifically, the format definition of the information element (Information Element, IE) of the broadcast frame is shown in Table 1. The information element IE is a component of the 802.11 management frame, and the management frame consists of two parts: a frame header and a frame body. The frame entity includes two parts: a fixed field and a series of information units. The information element IE consists of three parts: a 1-byte Element ID field, a 1-byte Length field, and a variable-length Information field.

Table 1

Element ID Length ServiceContent ServiceInfo

The above broadcast frame carries the service catalog and detailed service information of a certain type of service, that is, a type of service information group. Among them, Element ID is used to uniquely mark IE; Length marks the length of IE; ServiceContent is a service directory; ServiceInfo is detailed service information of a certain type of service, that is, a type of service information group.

In addition, when the access point sends the broadcast frame to the station in step 140, the broadcast frame may be sent according to a schedule. For example, three service information groups: a catering service information group, an entertainment service information group, and a transportation service information group. There are many ways for the access point to send the broadcast frame carrying the above three service information groups to the station. For example, as shown in FIG. The broadcast frame 22 of the entertainment service information group is after the first beacon period, and the broadcast frame 23 carrying the traffic service information group is after the second beacon period. Among them, the broadcast frame carrying the catering service information group, the broadcast frame carrying the entertainment service information group, and the broadcast frame carrying the traffic service information group form a broadcast period, which is 3 beacon periods. In addition, the broadcast cycle can be sent repeatedly according to the actual situation, and the length of the broadcast cycle can be changed according to the increase or decrease of the service type.

It should be noted that, in all the embodiments of the present invention, the beacon period is defined as: the period from sending the first broadcast frame to sending the second broadcast frame is a beacon period.

Therefore, in the service discovery method provided by the embodiment of the present invention, the access point classifies the service information according to different service information groups according to the summary information of each service information, determines the broadcast time of each service information group, and according to the service information The broadcast time and information identification of the group establishes a service directory, which includes the broadcast time and information identification of all service information groups, adds the service information group and the service directory to the broadcast frame, and sends the broadcast frame to the station , so that when the service directory is very small, it can be placed in each broadcast frame containing detailed service information of different service types, so that no matter which broadcast frame is received, you can know the broadcast containing other service information The broadcast time of the frame, which can reduce the number of times the broadcast frame is received in some cases, and can discover services more quickly.

FIG. 3 is a flowchart of a service discovery method provided by Embodiment 3 of the present invention. The service discovery method performed by the station side provided in this embodiment corresponds to the service discovery method performed by the access point side provided in the first embodiment. As shown in the figure, the embodiment of the present invention specifically includes the following steps:

Step 310, the station receives the broadcast frame carrying the service directory and service information group sent by the access point. Wherein, the service catalog includes the information identifier of the service information and the broadcast time of the service information group.

Step 320, the station finds the service information it needs from the service information group of the broadcast frame or obtains the broadcast time of the service information group where the service information it needs is located in the service directory of the broadcast frame.

In one embodiment, each broadcast frame in step 310 carries a service list and a type of service information set, the service information sets carried by each broadcast frame are different, and the service lists carried by each broadcast frame are the same. In this embodiment, the service directory and the service information group are in one broadcast frame, but the service directory and the service information group may not be in one broadcast frame, which will be described in detail in other embodiments. In step 320, after the station receives the broadcast frame sent by the access point, it uses two different processing methods to perform a series of processing on the broadcast frame, and the processing process of each processing method is as follows:

(1) The STA stops scanning when it obtains a detailed service information containing the service it wants, that is, the service information group it needs. In this way, the STA can enter a dormant state when it does not need to receive. The specific process is:

When the service information group of the received broadcast frame contains the service information it needs, the station stops receiving other broadcast frames.

When the service information group of the received broadcast frame does not contain the service information it needs, the station will learn from the service directory the broadcast time of the service information group where the service information it needs is the detailed service it needs After the exact broadcast time of the broadcast frame of the information, it will enter the dormant state, and only enter the receiving state at the broadcast time of the service information group where the service information it needs is located, so as to find the service it needs from the broadcast frame received at this time information.

(2) The STA needs to scan until it obtains all the detailed service information that contains the service it wants, that is, the service information group it needs. In this way, the STA must be in the listening state all the time. The specific process is:

When the service information group of the received broadcast frame contains the service information required by itself, the station just no longer receives other service information sent by the access point, and discards it, and still receives the service information sent by other access points. broadcast frame. Here, the discarding process involved in the embodiment of the present invention can be directly discarded without unpacking, or only unpacking the Medium Access Control (Medium Access Control, MAC) frame header, and confirming that it is the broadcast frame sent by the AP Throw it away. Among them, the MAC frame is divided into a data frame, a control frame, and a management frame. The Beacon we are talking about here is a management frame. The discarding process involved in other embodiments of the present invention is the same, and the detailed description will not be repeated.

When the service information group of the received broadcast frame does not contain the service information required by itself, and there is an information identifier of the service information corresponding to the service information required by itself and the broadcast time of the service information group in the service directory, then the station Receive the broadcast frame at the broadcast time of the service information group, and find the service information required by itself from the broadcast frame received at this time, and no longer receive other service information of the access point, and the access point Other broadcast frames are discarded. Because there may be multiple access points broadcasting information, the station will still receive information from other access points

However, when the service information group of the received broadcast frame does not contain the service information required by itself, and there is no information identification of the service information corresponding to the service information required by itself and the broadcast time of the service information group in the service directory , the station no longer receives the service information sent by the access point, and discards other broadcast frames of the access point.

Therefore, after the service discovery method provided by the embodiment of the present invention, the station receives the broadcast frame carrying the service catalog and service information group sent by the access point, it discovers the service information or service information it needs from the service information group of the broadcast frame. The broadcast time of the service information group where the service information required by itself is obtained from the service directory of the broadcast frame, so that when the service directory is small, it can be placed in each service information containing different service types In the broadcast frame of detailed service information, no matter which broadcast frame is received by the station, the broadcast time of the broadcast frame containing other service information can be known, so that the number of times of receiving broadcast frames can be reduced in some cases, and services can be found more quickly .

FIG. 4 is a flowchart of a service discovery method provided in Embodiment 4 of the present invention. As shown in the figure, the embodiment of the present invention specifically includes the following steps:

Step 410, the access point classifies each service information according to its content to obtain different service information groups, each service information group has an information identifier, and the service information in the content of each service information group belongs to the information identifier. The corresponding service type classifies all service information of the access point into different service information groups according to the summary information of each service information. Wherein, the service information in the service information group belongs to the same service type, and the service information group includes content information of all service information belonging to the same service type. However, the types of service information in different service information groups are different. This step is the same as step 110 and will not be repeated here.

Step 420, the access point determines the broadcast time of each service information group, and establishes a service directory according to the broadcast time and information identification of the service information group, the service directory includes the broadcast time and information identification of all service information groups, and determines the service directory broadcast time. This step is the same as step 120 and will not be repeated here. Wherein, the service directory also includes summary information of service information in each service information group.

Step 430, the access point adds the service catalog to the first broadcast frame, and adds the broadcast time and service information group of the service catalog to different second broadcast frames, so that the service information groups carried in each second broadcast frame are all Are not the same.

Specifically, in the embodiment of the present invention, the service catalog and the service information group are in different broadcast frames, the broadcast frame where the service catalog is located is defined as: the first broadcast frame, and the broadcast frame where the service information group is located is defined as: the first broadcast frame Two broadcast frames. Because there may be multiple service information groups, there may also be multiple second broadcast frames. For example, the second broadcast frame carrying the catering service information group, the second broadcast frame carrying the entertainment service information group, and the second broadcast frame carrying the transportation service information group.

Wherein, the format definition of the information element IE of the first broadcast frame carrying the service catalog is shown in Table 2. Element ID is used to uniquely mark IE; Length marks the length of IE; ServiceContent is service directory information.

Table 2

Element ID Length ServiceContent

Table 3 shows the format definition of the information element IE of the second broadcast frame carrying the service information group. Element ID is used to uniquely mark the IE; Length marks the length of the IE; ServiceInfo is the detailed service information of a certain type of service, that is, the content of the service information group; Time is the exact time of the Beacon broadcast carrying the service directory.

table 3

Element ID Length ServiceInfo Time

Step 440, the access point determines the broadcast period of the first broadcast frame and the second broadcast frame, and periodically sends the first broadcast frame and the second broadcast frame to the station according to the broadcast period, so that the station can obtain the service list from the first broadcast frame Know the broadcast time of the service information group in which the service information required by itself is located, and find the broadcast time of the service information or service list required by itself from the service information group of the second broadcast frame. There are many ways for the access point to send the first broadcast frame and the second broadcast frame to the station, and the first broadcast frame and the second broadcast frame may be sent in a scheduled manner.

In one embodiment, within a broadcast period, the first broadcast frame is sent only once, and each second broadcast frame carrying a different service information group is sent once respectively. For example, after the access point sends the first broadcast frame, it sends the second broadcast frame until all the second broadcast frames are sent, which is a broadcast cycle, and then executes the next broadcast cycle. In addition, the access point may also send the second broadcast frame first, and then send the first broadcast frame. Wherein, regardless of the first broadcast frame or the second broadcast frame, the beacon period between every two broadcast frames is the same.

Specifically, the manner in which the access point sends the first broadcast frame and the second broadcast frame to the station, for example, for the first broadcast frame carrying the service catalog, the second broadcast frame carrying the catering service information group, and the second broadcast frame carrying the entertainment class There are many ways to send the second broadcast frame of the service information group and the second broadcast frame of the service information group carrying traffic. As shown in Figure 5, the first broadcast frame 51 carrying the service catalog is sent first, and the second broadcast frame 52 carrying the service information group of catering is arranged after the first beacon period, carrying entertainment services The second broadcast frame 53 of the information group is after the second beacon period, and the second broadcast frame 54 carrying the traffic service information group is after the third beacon period. Among them, the first broadcast frame 51 carrying the service catalog, the second broadcast frame 52 carrying the catering service information group, the second broadcast frame 53 carrying the entertainment service information group, and the second broadcast frame 53 carrying the transportation service information group Two broadcast frames 54 form a broadcast period, which is 4 beacon periods. In addition, the broadcast cycle can be sent in multiple cycles according to the actual situation. Wherein, the sending period of the first broadcast frame 51 carrying the service catalog is 4 beacon periods.

In yet another embodiment, within the broadcast period, the first broadcast frame is sent multiple times, each second broadcast frame carrying a different service information group is sent once, and one or more frames are sent before or after each second broadcast frame is sent. A plurality of first broadcast frames, wherein the number of bytes occupied by the first broadcast frame is smaller than the number of bytes occupied by the second broadcast frame. For example, the IE frame formats of the first broadcast frame and the second broadcast frame are shown in Table 3. The access point may send the second broadcast frames in sequence, and send the first broadcast frame between each second broadcast frame, until all the second broadcast frames are sent, which is a broadcast cycle, and then executes the next broadcast cycle. Among them, one or more first broadcast frames are sent between two second broadcast frames. In this embodiment, the first broadcast frame with a higher sending frequency is used to carry the service list, and the purpose is to improve the efficiency of the station receiving the service list. probability, making the site discover services more quickly.

Specifically, in the embodiment of the present invention, the first broadcast frame occupying a relatively small number of bytes is defined as a short beacon; the second broadcast frame occupying a relatively large number of bytes is defined as a long beacon. When the access point sends the second broadcast frame sequentially, for example, according to first sending the second broadcast frame carrying the service information group of catering, then sending the second broadcast frame carrying the service information group of entertainment, and finally sending the second broadcast frame carrying the service information group of traffic Sequential transmission of the second broadcast frame of the service information group. However, one or more first broadcast frames, namely short beacons, are also sent between two second broadcast frames, namely long beacons. As shown in Figure 6, after sending the second broadcast frame 61 carrying the service information group of catering, five first broadcast frames 60 carrying the service catalog are sent continuously, and then the second broadcast frame 60 carrying the service information group of entertainment is sent After the frame 62, five first broadcast frames 60 carrying the service catalog are sent continuously, and finally, after the second broadcast frame 63 carrying the traffic service information group is sent, five first broadcast frames carrying the service catalog are continuously sent 60. Up to now, a complete broadcast cycle has been formed, and the broadcast cycle can be transmitted multiple times according to the actual situation. Wherein, regardless of the first broadcast frame or the second broadcast frame, the beacon period between every two broadcast frames is a short beacon period, but the beacon period between every two second broadcast frames is a long beacon period.

Therefore, in the service discovery method provided by the embodiment of the present invention, the access point classifies the service information according to different service information groups according to the summary information of each service information, determines the broadcast time of each service information group, and sends the The summary information of each service information and the broadcast time of each service information group form a service directory, add the service directory to the first broadcast frame, and add the broadcast time and service information group of the service directory to different second In the broadcast frame, the service information group carried by each second broadcast frame is different, and the first broadcast frame and the second broadcast frame are sent to the station. When the station receives the first broadcast frame or the second broadcast frame sent by the access point , realize the use of AP to classify all service information, and add the service list to the first broadcast frame, and add the broadcast time and service information group of the service list to different second broadcast frames, and send the first broadcast frame to the station The broadcast frame and the second broadcast frame enable the station to receive the required service information at the moment of learning according to the first broadcast frame and the second broadcast frame, without receiving all the service information, which reduces the power consumption of the STA and can support large data Amount of passive service discovery.

FIG. 7 is a flowchart of a service discovery method provided by Embodiment 7 of the present invention. The service discovery method performed by the station side provided in this embodiment corresponds to the service discovery method performed by the access point side provided in Embodiment 4. As shown in the figure, the embodiment of the present invention specifically includes the following steps:

Step 710, the station receives the broadcast frame carrying the service catalog and service information group sent by the access point, wherein the service catalog includes the information identifier of the service information and the broadcast time of the service information group, and the received broadcast frame includes the first broadcast frame and Second broadcast frame.

Specifically, the station receives the first broadcast frame carrying the service directory or the second broadcast frame carrying the broadcast time and service information group of the service directory sent by the access point, wherein the service information group carried by each second broadcast frame is Are not the same.

Step 720, the station discovers the service information it needs from the service information group of the broadcast frame, or the broadcast time of the service list, or learns from the service list of the broadcast frame the time of the service information group where the service information it needs is located broadcast time. Wherein, the received broadcast frame includes a first broadcast frame and a second broadcast frame. The first broadcast frame carries a service list, and the second broadcast frame carries a type of service information group and the broadcast time of the service list.

Specifically, after the station receives the broadcast frame sent by the access point, it uses two different processing methods to perform a series of processing on the first broadcast frame or the second broadcast frame, and the processing process of each processing method is as follows:

(1) The STA stops scanning when it obtains a detailed service information containing the service it wants, that is, the service information group it needs. In this way, the STA can enter a dormant state when it does not need to receive. The specific process is:

When the first broadcast frame is received, after knowing the broadcast time of the service information group where the service information required by itself is located in the service directory carried by the first broadcast frame, it enters the dormant state, and only the service information required by itself The broadcast time of the service information group it is in enters the receiving state, so as to find the service information it needs from the received broadcast frame.

When the second broadcast frame is received, and the service information group carried by the second broadcast frame contains the service information required by itself, the station stops receiving other broadcast frames sent by the access point;

When the second broadcast frame is received, and the service information group carried by the second broadcast frame does not contain the service information required by itself, after the broadcast time of the service list is known according to the second broadcast frame, it enters the dormant state, and only Enter the receiving state at the broadcast time of the service directory, and after knowing the broadcast time of the service information group where the service information required by itself is obtained from the received first broadcast frame carrying the service directory, then enter the dormant state. The broadcast time of the service information group where the service information required by itself enters the receiving state, so as to find the service information required by itself from the received second broadcast frame carrying the service information group.

(2) The STA needs to scan until it obtains all the detailed service information that contains the service it wants, that is, the service information group it needs. In this way, the STA must be in the listening state all the time. The specific process is:

When the first broadcast frame carrying the service directory is received, and there is an information identifier of the service information corresponding to the service information required by itself and the broadcast time of the service information group in the service directory, then in the broadcast of the service information group Timely receive the second broadcast frame, and find the service information required by itself from the received second broadcast frame, and discard other broadcast frames of the access point, such as the first broadcast frame or the second broadcast frame ;

When the first broadcast frame carrying the service catalog is received, and there is no information identifier of the service information corresponding to the service information required by itself and the broadcast time of the service information group in the service catalog, the station no longer receives the broadcast frame. The service information sent by the access point is discarded for other broadcast frames of the access point, for example, the first broadcast frame or the second broadcast frame.

When the second broadcast frame is received, and the service information group carried by the second broadcast frame contains the service information it needs, the station will no longer receive other service information. For other broadcast frames of the access point, For example, the first broadcast frame or the second broadcast frame is discarded.

When the second broadcast frame is received, and the service information group carried by the second broadcast frame does not contain the service information required by itself, then the broadcast time of the service list is known according to the second broadcast frame, so that the site can register in the service list The first broadcast frame is received at the broadcast time.

In addition, when the first broadcast frame is a beacon and the second broadcast frame is also a beacon, but the number of bytes occupied by the first broadcast frame is less than the number of bytes occupied by the second broadcast frame, the station will Or the processing process of the second broadcast frame is the same as above, and will not be repeated here.

Therefore, in the service discovery method provided by the embodiment of the present invention, the station receives the broadcast frame carrying the service catalog and the service information group sent by the access point, wherein the service catalog includes the information identifier of the service information and the broadcast time of the service information group, and receives The broadcast frame includes the first broadcast frame and the second broadcast frame. According to the service catalog and service information group carried by the received broadcast frame, the service information required by itself is discovered, and the station realizes the The required service information is received at the moment of acquisition, instead of all service information, which reduces the power consumption of the STA and can support passive service discovery with a large amount of data.

FIG. 8 is a schematic diagram of an access point provided in Embodiment 8 of the present invention. The access point is used to execute the service discovery methods provided in the first to seventh embodiments of the present invention. As shown in the figure, the embodiment of the present invention specifically includes: a classification unit 81 , a processing unit 82 , an adding unit 83 and a sending unit 84 .

The classification unit 81 is used to classify the content of each service information to obtain different service information groups, each service information group has a summary information identifying each service information, and the service information in each service information group The content belongs to the service type corresponding to the information identification, and the service information group is transmitted to the processing unit 82; the processing unit 82 is used for receiving the service information group from the classification unit 81, determining the broadcast time of each service information group, and according to the service information The broadcast time and information identification of the group set up a service directory, which includes the broadcast time and information identification of all service information groups, and transmits the service information group and the service directory to the adding unit 83; the adding unit 83 is used to receive from the processing unit 82 The service information group and the service catalog, adding the service information group and the service catalog to the broadcast frame, and transmitting the broadcast frame to the sending unit 84; the sending unit 84 is used to receive the broadcast frame from the adding unit 83, and determine the broadcast period of the broadcast frame, And periodically send a broadcast frame to the station according to the broadcast cycle, so that the station can find the service information it needs from the service information group of the broadcast frame or learn the service information it needs from the service list of the broadcast frame. The broadcast time of the service information group where the service information is located.

In one embodiment, the service directory further includes summary information of service information in each service information group, and the adding unit 83 is used to add the service information group to each broadcast frame respectively, and add the service directory to each broadcast frame , so that the service information groups carried by each broadcast frame are different, and the service catalogs carried by each broadcast frame are the same, wherein each broadcast frame carries a service catalog and a type of service information group.

In another embodiment, the service catalog further includes summary information of service information in each service information group, and the processing unit 82 is also configured to determine the broadcast time of the service catalog. The broadcast frames involved in this embodiment include: a first broadcast frame and a second broadcast frame. The adding unit 83 is used to add the service catalog to the first broadcast frame, and add the broadcast time and service information group of the service catalog to different second broadcast frames, so that the service information groups carried by each second broadcast frame are different. same. The sending unit 84 is used to send the first broadcast frame to the station, so that the station can learn from the first broadcast frame the broadcast time when the access point sends the service information required by itself, and send the second broadcast frame to the station, so that the station can obtain the broadcast time from the second broadcast frame. Discover the service information required by itself in the broadcast frame.

Wherein, in the broadcast period of the sending unit 84, the first broadcast frame is only sent once, and the second broadcast frames each carrying a different service information group are sent once respectively; or the first broadcast frame is sent multiple times, each carrying a different service information group The second broadcast frame is sent once respectively, and one or more first broadcast frames are sent before each second broadcast frame is sent, wherein the number of bytes occupied by the first broadcast frame is less than the number of bytes occupied by the second broadcast frame number of bytes. Therefore, the access point has multiple forms of sending the first broadcast frame and the second broadcast frame, for example: after sending the first broadcast frame, and then sending the second broadcast frame, until all the second broadcast frames are sent is a broadcast cycle, Then execute the next broadcast cycle; or send the second broadcast frames in sequence, and send one or more first broadcast frames between each second broadcast frame, until all the second broadcast frames are sent to be a broadcast cycle, and then Execute the next broadcast cycle.

Therefore, the access point provided by the embodiment of the present invention classifies the service information according to different service information groups according to the summary information of each service information, determines the broadcast time of each service information group, and classifies each service information The summary information of the information and the broadcast time of each service information group form a service directory, add the service information group and the service directory to the broadcast frame, and send the broadcast frame to the station, realizing the use of AP to send all The service information is classified and sent to the STA, and the STA receives the required service information at the moment of learning, instead of receiving all the service information, which reduces the power consumption of the STA and can support passive service discovery with a large amount of data.

FIG. 9 is a schematic diagram of a site provided by Embodiment 9 of the present invention. The site is used to execute the service discovery methods provided in Embodiments 1 to 7 of the present invention. As shown in the figure, the embodiment of the present invention specifically includes: a receiving unit 91 and a discovery unit 92 .

The receiving unit 91 is used to receive the broadcast frame carrying the service directory and the service information group sent by the access point, the service directory includes the information identifier of the service information and the broadcast time of the service information group, and transmits the broadcast frame to the discovery unit 92; the discovery unit 92 is used to receive the broadcast frame from the receiving unit, find the service information required by itself from the service information group of the broadcast frame or obtain the broadcast time of the service information group where the service information required by itself is located in the service directory of the broadcast frame.

When there are both a service directory and a service information group in the broadcast frame, in one embodiment, the discovery unit 92 is used to stop the station from receiving when the service information group of the received broadcast frame contains the service information it needs. Other broadcast frames sent by the access point; when the service information group of the received broadcast frame does not contain the service information required by itself, the station will learn the service information group of the service information it needs from the service directory After the broadcast time, it enters the sleep state, and only enters the receiving state at the broadcast time of the service information group where the service information it needs is located, so as to find the service information it needs from the received broadcast frame.

In another embodiment, the discovery unit 92 is configured to, when the service information group of the received broadcast frame contains the service information it needs, the station will no longer receive other service information sent by the access point. Other broadcast frames sent by the point are discarded; when the service information group of the received broadcast frame does not contain the service information required by itself, and there is an information identifier of the service information corresponding to the service information required by itself in the service directory and the broadcast time of the service information group, then receive the broadcast frame at the broadcast time of the service information group, and find the service information required by itself from the received broadcast frame, and discard other broadcast frames sent by the access point. In addition, the discovery unit 92 is also used for when the service information group of the received broadcast frame does not contain the service information required by itself, and there is no information identification and information of service information corresponding to the service information required by itself in the service directory. broadcast time of the service information group, the station no longer receives the service information sent by the access point, and discards other broadcast frames sent by the access point.

When the broadcast frame includes the first broadcast frame and the second broadcast frame, the receiving unit 91 is configured to receive the first broadcast frame carrying the service catalog or the second broadcast carrying the broadcast time and service information group of the service catalog sent by the access point frames, wherein the service information groups carried by each second broadcast frame are different.

In one embodiment, the discovery unit 92 is configured to, when receiving the first broadcast frame, obtain the broadcast time of the service information group in which the service information required by itself is located from the service directory carried in the first broadcast frame, and then enter Dormant state, only enters the receiving state at the broadcast time of the service information group where the service information required by itself is located, so as to find the service information required by itself from the received broadcast frame; when the second broadcast frame is received, and When the service information group carried by the second broadcast frame contains the service information it needs, the station stops receiving other broadcast frames. In addition, the discovery unit 92 is also configured to obtain the broadcast of the service list according to the second broadcast frame when the second broadcast frame is received and the service information group carried by the second broadcast frame does not contain the service information required by itself. After the time, enter the dormant state, only enter the receiving state at the broadcast time of the service catalog, and after knowing the broadcast time of the service information group where the service information required by itself is located in the first broadcast frame carrying the service catalog received, Then enter the dormant state, and only enter the receiving state at the broadcast time of the service information group where the service information required by itself is, so as to find the service information it needs from the received second broadcast frame carrying the service information group.

In another embodiment, the discovery unit 92 is configured to receive the first broadcast frame carrying the service directory, and there is an information identifier and service information of the service information corresponding to the service information required by itself in the service directory group broadcast time, then receive the second broadcast frame at the broadcast time of the service information group, and find the service information required by itself from the received second broadcast frame, for other first broadcast frames sent by the access point Or the second broadcast frame is discarded; when the first broadcast frame carrying the service directory is received, and there is no information identifier of the service information and service information group corresponding to the service information required by itself in the service directory broadcast time, the station no longer receives service information sent by the access point, and discards the first broadcast frame or the second broadcast frame for other broadcast frames sent by the access point. In addition, the discovery unit 92 is configured to receive the second broadcast frame, and when the service information group carried by the second broadcast frame contains the service information required by itself, the station will no longer receive other service information. Other broadcast frames sent by the ingress, such as the second broadcast frame or the first broadcast frame, are discarded; when the second broadcast frame is received, and the service information group carried by the second broadcast frame does not contain the required When the service information is displayed, the broadcast time of the service list is obtained according to the second broadcast frame, so that the station receives the first broadcast frame at the broadcast time of the service list.

Therefore, in the station provided by the embodiment of the present invention, after receiving the broadcast frame carrying the service catalog and service information group sent by the access point, the station finds the service information it needs from the service information group of the broadcast frame or finds the service information it needs from the service information group of the broadcast frame. In the service directory, the broadcast time of the service information group where the service information required by itself is known, so that the AP can use the AP to classify all the service information and send it to the STA, and the STA receives the required service information at the moment when it is known, without receiving all the service information. The service information reduces the power consumption of STA, and can support passive service discovery with a large amount of data.

FIG. 10 is a schematic diagram of an access point provided by Embodiment 10 of the present invention. The access point is used to implement the passive service discovery method provided by the first to seventh embodiments of the present invention. As shown in the figure, the embodiment of the present invention specifically includes: as shown in the figure, the access point 100 includes: a transmitting circuit 102, a receiving circuit 103, a power controller 104, a decoding processor 105, a processing unit 106, a memory 107 and an antenna 101. The processing unit 106 controls the operation of the access point 100, and the processing unit 106 may also be referred to as a CPU. The memory 107 may include read-only memory and random-access memory, and provides instructions and data to the processing unit 106 . A portion of memory 107 may also include non-volatile random access memory (NVRAM). In a specific application, the access point 100 can be embedded or itself can be a wireless communication device such as a mobile phone, and can also include a carrier for accommodating the transmitting circuit 102 and the receiving circuit 103, so as to allow communication between the access point 100 and a remote location. For data transmission and reception. Transmit circuitry 102 and receive circuitry 103 may be coupled to antenna 101 . Various components of the access point 100 are coupled together through a bus system 1000, wherein the bus system 1000 includes a power bus, a control bus, and a status signal bus in addition to a data bus. However, for the sake of clarity, the various buses are labeled as bus system 1000 in the figure. The access point 100 may further include a processing unit 106 for processing signals, a power controller 104 , and a decoding processor 105 . In specific different products, the decoder 105 may be integrated with the processing unit 106 .

The processor may implement or execute the steps and logic block diagrams disclosed in the method embodiments of the present invention. A general purpose processor can be a microprocessor or the processor can be any conventional processor, decoder, etc. The steps of the methods disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the field such as random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, register. The storage medium is located in the memory 107, and the decoding unit or the processing unit reads the information in the memory 107, and combines with its hardware to complete the steps of the passive service discovery method provided by Embodiments 1 to 7 of the present invention.

FIG. 11 is a schematic diagram of a site provided by Embodiment 11 of the present invention. The site is used to implement the passive service discovery method provided by Embodiments 1 to 7 of the present invention. As shown in the figure, the station 110 includes: a transmitting circuit 112 , a receiving circuit 113 , a power controller 114 , a decoding processor 115 , a processing unit 116 , a memory 117 and an antenna 111 . The processing unit 116 controls the operation of the station 110, and the processing unit 116 may also be referred to as a CPU. Memory 117 may include read-only memory and random-access memory, and provides instructions and data to processing unit 116 . A portion of memory 117 may also include non-volatile random access memory (NVRAM). In a specific application, the station 110 may be embedded or itself may be a wireless communication device such as a mobile phone, and may also include a carrier for accommodating the transmitting circuit 112 and the receiving circuit 113, so as to allow data transmission and communication between the station 110 and a remote location. take over. Transmit circuitry 112 and receive circuitry 113 may be coupled to antenna 111 . Various components of the site 110 are coupled together through a bus system 1100, wherein the bus system 1100 includes a power bus, a control bus, and a status signal bus in addition to a data bus. However, for the sake of clarity, the various buses are labeled as bus system 1100 in the figure. The station 110 may also include a processing unit 116 for processing signals, in addition to a power controller 114 , a decoding processor 115 . In specific different products, the decoder 115 may be integrated with the processing unit 116 .

The processor may implement or execute the steps and logic block diagrams disclosed in the method embodiments of the present invention. A general purpose processor can be a microprocessor or the processor can be any conventional processor, decoder, etc. The steps of the methods disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the field such as random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, register. The storage medium is located in the memory 117, and the decoding unit or the processing unit reads the information in the memory 117, and combines with its hardware to complete the steps of the passive service discovery method provided by Embodiments 1 to 7 of the present invention.

Professionals should further realize that the units and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the relationship between hardware and software Interchangeability. In the above description, the composition and steps of each example have been generally described according to their functions. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present invention.

The steps of the methods or algorithms described in connection with the embodiments disclosed herein may be implemented by hardware, software modules executed by a processor, or a combination of both. Software modules can be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other Any other known storage medium.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the scope of the present invention. Protection scope, within the spirit and principles of the present invention, any modification, equivalent replacement, improvement, etc., shall be included in the protection scope of the present invention.

Claims (28)

1. A service discovery method, characterized in that the method comprises: The access point classifies each service information according to its content to obtain different service information groups. Each service information group has an information identifier, and the service information content in each service information group belongs to the information corresponding to the information identifier. type of service; The access point determines the broadcast time of each service information group, and establishes a service directory according to the broadcast time and information identifiers of the service information groups, and the service directory includes the broadcast times and information identifiers of all service information groups; The access point adds the service information group and the service catalog to a broadcast frame, wherein each broadcast frame includes at least one of a type of the service information group and the service catalog; The access point determines the broadcast period of the broadcast frame, and periodically sends the broadcast frame to the station according to the broadcast period, so that the station can discover the service it needs from the service information group of the broadcast frame information or learn from the service directory of the broadcast frame the broadcast time of the service information group where the service information required by itself and the broadcast time of the service information group where other service information is located; Wherein, the service catalog further includes summary information of the service information in each service information group, and adding the service information group and the service catalog to the broadcast frame includes: Adding the service information group to each broadcast frame, and adding the service directory to each broadcast frame, so that the service information groups carried by each broadcast frame are different, and each broadcast frame The service catalogs carried are all the same, wherein each broadcast frame carries a service catalog and a type of service information group. 2. The service discovery method according to claim 1, wherein the service catalog further includes summary information of service information in each service information group; The determining the broadcast time of each service information group, and establishing a service directory according to the broadcast time and information identification of the service information group also includes: The broadcast time of the service catalog is determined according to the broadcast time of each service information group. 3. The service discovery method according to claim 2, wherein the broadcast frame comprises: a first broadcast frame and a second broadcast frame; Adding the service list to the first broadcast frame, and adding the broadcast time of the service list and the service information group to different second broadcast frames, so that the service information groups carried by each second broadcast frame are all Are not the same. 4. The service discovery method according to claim 3, wherein the periodically sending the broadcast frame to the station according to the broadcast cycle comprises: Periodically send the first broadcast frame and the second broadcast frame to the station according to the broadcast cycle, so that the station can learn from the service directory of the first broadcast frame where the service information required by itself is located. The broadcast time of the service information group, and discover the service information required by itself and the broadcast time of the service list from the service information group of the second broadcast frame. 5. The service discovery method according to claim 4, wherein periodically sending the first broadcast frame and the second broadcast frame to the station according to the broadcast cycle comprises: In the broadcast period, the first broadcast frame is sent only once, and the second broadcast frames carrying different service information groups are sent once respectively. 6. The service discovery method according to claim 4, wherein periodically sending the first broadcast frame and the second broadcast frame to the station according to the broadcast period comprises: In the broadcast period, the first broadcast frame is sent multiple times, each of the second broadcast frames carrying different service information groups is sent once, and one or more broadcast frames are sent before or after each second broadcast frame is sent. a first broadcast frame, wherein the number of bytes occupied by the first broadcast frame is smaller than the number of bytes occupied by the second broadcast frame. 7. A service discovery method, characterized in that the method comprises: The station receives the broadcast frame carrying the service catalog and the service information group sent by the access point, the service catalog includes the information identifier of the service information and the broadcast time of the service information group, wherein each broadcast frame includes one type of all At least one of the above service information groups and service catalogs; wherein, the service information groups are different service information groups that the access point classifies according to the content of each service information, and each service information group has an information identifier , the content of the service information in each service information group belongs to the service type corresponding to the information identifier; the service directory is that the access point determines the broadcast time of each service information group, and according to the The broadcast time and information identification of the service information group establishes a service directory, and the service directory includes the broadcast time and information identification of all service information groups; The station discovers the service information it needs from the service information group of the broadcast frame or learns the broadcast time and other service information of the service information group where the service information it needs is located in the service directory of the broadcast frame. The broadcast time of the service information group where the information is located; Wherein, the service directory further includes summary information of service information in each service information group, and the access point adds the service information group to each broadcast frame, and adds the service directory to each In the above broadcast frames, the service information groups carried by the broadcast frames are different, and the service lists carried by the broadcast frames are all the same, wherein each broadcast frame carries a service list and a type of Service information group. 8. The service discovery method according to claim 7, wherein the service information required by the self is discovered from the service information group of the broadcast frame or the service information of the self is obtained from the service directory of the broadcast frame. The broadcast time of the service information group in which the required service information is located, including: When the service information group of the received broadcast frame contains the service information required by itself, the station stops receiving other broadcast frames sent by the access point; When the service information group of the received broadcast frame does not contain the service information required by itself, the station obtains the service information of the service information required by itself from the service directory After the broadcast time of the group, enter the dormant state, and enter the receiving state at the broadcast time of the service information group where the service information required by itself is located, and find the service information required by itself from the received broadcast frame. 9. The service discovery method according to claim 7, wherein the service information required by the self is discovered from the service information group of the broadcast frame or the service information of the self is obtained from the service directory of the broadcast frame The broadcast time of the service information group in which the required service information is located, including: When the service information group of the received broadcast frame contains the service information required by itself, the station will no longer receive other service information sent by the access point. For the access Other broadcast frames sent by the point are discarded; When the service information group of the received broadcast frame does not contain the service information required by itself, and the service information corresponding to the service information required by itself exists in the service directory information identification and the broadcast time of the service information group, then receive the broadcast frame at the broadcast time of the service information group, and find the service information required by the self from the received broadcast frame, for the access point Other broadcast frames sent are discarded; When the service information group of the received broadcast frame does not contain the service information required by itself, and the service information corresponding to the service information required by itself does not exist in the service directory and the broadcast time of the service information group, the station no longer receives the service information sent by the access point, and discards other broadcast frames sent by the access point. 10. The service discovery method according to claim 7, wherein the broadcast frame comprises a first broadcast frame and a second broadcast frame; receiving the first broadcast frame carrying the service catalog sent by the access point, and receiving the second broadcast frame carrying the broadcast time of the service catalog and the service information group, wherein each second broadcast frame carries The service information groups are all different. 11. The service discovery method according to claim 10, wherein the service information required by the self is discovered from the service information group of the broadcast frame or the service information of the self is obtained from the service directory of the broadcast frame The broadcast time of the service information group in which the required service information is located, including: When the first broadcast frame is received, after learning the broadcast time of the service information group in which the service information required by the self is obtained from the service directory carried by the first broadcast frame, enter the dormant state, and Enter the receiving state at the broadcast time of the service information group where the service information required by itself is located, and find the service information required by itself from the received broadcast frame; When the second broadcast frame is received, and the service information group carried by the second broadcast frame contains the service information required by itself, the station stops receiving the information sent by the access point. other broadcast frames. 12. The service discovery method according to claim 10 or 11, wherein the service information required by itself is discovered from the service information group of the broadcast frame or the service information is obtained from the service directory of the broadcast frame. The broadcast time of the service information group in which the service information required by itself is located, including: When the second broadcast frame is received, and the service information group carried by the second broadcast frame does not contain the service information required by itself, learn the After the broadcast time of the service catalog, enter the dormant state, and enter the receiving state at the broadcast time of the service catalog; After knowing the broadcast time of the service information group in which the service information required by the self is obtained from the received first broadcast frame carrying the service catalog, and then enter the dormant state, The broadcast time of the service information group where the service information is located enters the receiving state, and the service information required by itself is found from the received second broadcast frame carrying the service information group. 13. The service discovery method according to claim 10, wherein the service information required by the self is discovered from the service information group of the broadcast frame or the service information of the self is obtained from the service directory of the broadcast frame The broadcast time of the service information group in which the required service information is located, including: When the first broadcast frame carrying the service directory is received, and there is an information identifier of the service information and a service information group corresponding to the service information required by the service directory in the service directory broadcast time, then receive the second broadcast frame at the broadcast time of the service information group, and find the service information required by the self from the received second broadcast frame, and send to the access point The other first broadcast frame or the second broadcast frame is discarded; When the first broadcast frame carrying the service catalog is received, and there is no information identifier and service information group of the service information corresponding to the service information required by itself in the service catalog broadcast time, the station no longer receives the service information sent by the access point, and discards other first broadcast frames or second broadcast frames sent by the access point. 14. The service discovery method according to claim 10 or 13, wherein the service information required by itself is discovered from the service information group of the broadcast frame or the service information is obtained from the service directory of the broadcast frame. The broadcast time of the service information group in which the service information required by itself is located, including: When the second broadcast frame is received, and the service information group carried by the second broadcast frame contains the service information required by itself, the station no longer receives the access point The sent service information is discarded for other second broadcast frames or first broadcast frames sent by the access point; When the second broadcast frame is received, and the service information group carried by the second broadcast frame does not contain the service information required by itself, the The broadcast time of the service list is used for the station to receive the first broadcast frame at the broadcast time of the service list. 15. An access point, characterized in that, the access point comprises: The classification unit is used to classify each service information according to its content to obtain different service information groups. Each service information group has a piece of information identifying the summary information of each service information. The service information in each service information group The content belongs to the service type corresponding to the information identifier, and the service information group is transmitted to the processing unit; A processing unit, configured to receive the service information group from the classification unit, determine the broadcast time of each service information group, and establish a service catalog according to the broadcast time and information identifier of the service information group, the service catalog Including the broadcast time and information identification of all service information groups, and transmitting the service information groups and the service catalog to the adding unit; an adding unit configured to receive the service information set and the service catalog from the processing unit, add the service information set and the service catalog to a broadcast frame, and transmit the broadcast frame to a sending unit, Wherein, each said broadcast frame includes at least one of a type of said service information group and a service catalog; A sending unit, configured to receive the broadcast frame from the adding unit, determine the broadcast period of the broadcast frame, and periodically send the broadcast frame to the station according to the broadcast period, so that the station can provide services from the broadcast frame Finding the service information required by itself in the information group or learning from the service directory of the broadcast frame the broadcast time of the service information group in which the service information required by itself is located and the broadcast time of the service information group in which other service information is located; The service directory also includes summary information of service information in each service information group, and the adding unit is configured to add the service information group to each broadcast frame, and add the service directory to In the broadcast frames, the service information groups carried by the broadcast frames are different, and the service catalogs carried by the broadcast frames are all the same, wherein each broadcast frame carries a service catalog and a type of service information group. 16. The access point according to claim 15, wherein the service directory further includes summary information of service information in each service information group, and the processing unit is further configured to The broadcast time of the service information set determines the broadcast time of the service catalog. 17. The access point according to claim 16, wherein the broadcast frame comprises: a first broadcast frame and a second broadcast frame; the adding unit is configured to add the service list to the first broadcast frame , and add the broadcast time of the service catalog and the service information group to different second broadcast frames, so that the service information groups carried in each second broadcast frame are different. 18. The access point according to claim 17, wherein the sending unit is configured to periodically send the first broadcast frame and the second broadcast frame to the station according to the broadcast cycle for the The station obtains the broadcast time of the service information group in which the service information required by itself is located from the service directory of the first broadcast frame, and finds the service information required by itself from the service information group of the second broadcast frame and the broadcast time of the service catalog. 19. The access point according to claim 18, wherein the sending unit is further configured to send the first broadcast frame only once within the broadcast period, and each of the frames carries different service information groups The second broadcast frames are sent once respectively. 20. The access point according to claim 18, wherein the sending unit is further configured to send the first broadcast frame multiple times within the broadcast period, each carrying a different set of service information The second broadcast frame is sent once respectively, and one or more first broadcast frames are sent before or after each second broadcast frame is sent, wherein the number of bytes occupied by the first broadcast frame is smaller than that of the second broadcast frame The number of bytes occupied. 21. A site, characterized in that the site comprises: The receiving unit is configured to receive a broadcast frame carrying a service catalog and a service information group sent by the access point, the service catalog including the information identifier of the service information and the broadcast time of the service information group, and transmit the broadcast frame to the discovery unit , wherein, each of the broadcast frames includes at least one of a type of the service information group and a service directory; wherein, the service information group is obtained by classifying the service information according to the content of each service information Different service information groups, each service information group has an information identifier, and the content of the service information in each service information group belongs to the service type corresponding to the information identifier; the service directory is determined by the access point The broadcast time of each service information group, and establish a service directory according to the broadcast time and information identification of the service information group, the service directory includes the broadcast time and information identification of all service information groups; A discovery unit, configured to receive the broadcast frame from the receiving unit, discover the service information required by itself from the service information group of the broadcast frame or obtain the service information required by itself from the service catalog of the broadcast frame The broadcast time of the service information group where the service information is located and the broadcast time of the service information group where other service information is located; Wherein, the service directory further includes summary information of service information in each service information group, and the access point adds the service information group to each broadcast frame, and adds the service directory to each In the above broadcast frames, the service information groups carried by the broadcast frames are different, and the service lists carried by the broadcast frames are all the same, wherein each broadcast frame carries a service list and a type of Service information group. 22. The station according to claim 21, wherein the discovery unit is configured to: when the service information group of the received broadcast frame contains the service information required by itself, then the The station stops receiving other broadcast frames sent by the access point; when the service information group of the received broadcast frame does not contain the service information required by itself, the station starts from the service After knowing the broadcast time of the service information group in which the service information required by itself is located in the directory, it enters the dormant state, and enters the receiving state at the broadcast time of the service information group in which the service information required by itself is located. Discover the service information required by itself in the broadcast frame. 23. The station according to claim 21, wherein the discovery unit is configured to: when the service information group of the received broadcast frame contains the service information required by itself, the The station no longer receives other service information sent by the access point, and discards other broadcast frames sent by the access point; when the service information group of the received broadcast frame does not contain the The service information required by itself, and the information identification of the service information corresponding to the service information required by itself and the broadcast time of the service information group exist in the service directory, then the broadcast of the service information group Receive broadcast frames in time, and discover the service information required by the self from the received broadcast frames, and discard other broadcast frames sent by the access point; The service information group does not contain the service information required by the self, and the information identification of the service information and the broadcast time of the service information group corresponding to the service information required by the service directory do not exist , the station no longer receives the service information sent by the access point, and discards other broadcast frames sent by the access point. 24. The station according to claim 21, wherein the broadcast frame includes a first broadcast frame and a second broadcast frame, and the receiving unit is configured to receive the first broadcast frame carrying the service catalog sent by the access point A broadcast frame, and receiving a second broadcast frame carrying the broadcast time of the service list and the service information group, wherein the service information groups carried by each second broadcast frame are different. 25. The station according to claim 24, wherein the discovering unit is configured to, when receiving the first broadcast frame, obtain the self from the service catalog carried in the first broadcast frame After the broadcast time of the service information group where the required service information is located, enter the dormant state, and enter the receiving state at the broadcast time of the service information group where the service information required by itself is located, and find the said The service information required by itself; when the second broadcast frame is received, and the service information group carried by the second broadcast frame contains the service information required by itself, the station stops receiving other broadcast frames sent by the access point. 26. The station according to claim 24 or 25, wherein the discovery unit is further configured to receive the second broadcast frame and the service information group carried by the second broadcast frame When it does not contain the service information required by itself, it will enter the dormant state after learning the broadcast time of the service list according to the second broadcast frame, and enter the receiving state at the broadcast time of the service list; After knowing the broadcast time of the service information group where the service information required by the self is obtained in the first broadcast frame carrying the service catalog, and then enters the dormant state, where the service information required by the self is located The broadcast time of the service information group enters the receiving state, and finds the service information required by itself from the received second broadcast frame carrying the service information group. 27. The station according to claim 24, wherein the discovery unit is configured to receive the first broadcast frame carrying the service directory, and the service directory exists in the The information identifier of the service information and the broadcast time of the service information group corresponding to the service information required by itself, then receive the second broadcast frame at the broadcast time of the service information group, and receive the second broadcast frame from the received first The service information required by the self is found in the second broadcast frame, and the other first broadcast frame or second broadcast frame sent by the access point is discarded. The first broadcast frame, and the information identification of the service information corresponding to the service information required by itself and the broadcast time of the service information group do not exist in the service directory, then the station no longer receives the received The service information sent by the access point is discarded for other first broadcast frames or second broadcast frames sent by the access point. 28. The station according to claim 24 or 27, wherein the discovery unit is configured to receive the second broadcast frame and the service information group carried by the second broadcast frame When the service information required by itself is included, the station no longer receives other service information, and discards other second broadcast frames or first broadcast frames sent by the access point; when the received The second broadcast frame, and the service information group carried by the second broadcast frame does not contain the service information required by itself, then obtain the broadcast time of the service catalog according to the second broadcast frame , used for the station to receive the first broadcast frame at the broadcast time of the service directory.