WO2021036468A1

WO2021036468A1 - Communication method and system for wireless local area network (wlan)

Info

Publication number: WO2021036468A1
Application number: PCT/CN2020/098630
Authority: WO
Inventors: 戴超
Original assignee: 南京中兴新软件有限责任公司
Priority date: 2019-08-27
Filing date: 2020-06-28
Publication date: 2021-03-04
Also published as: CN112449363A

Abstract

Disclosed in the embodiments of the present application are a communication method and system for a wireless local area network (WLAN). Said method comprises: an access point (AP) and a wireless terminal (STA) associated with a normal WLAN negotiate to enter a dual-mode transmission mode, the AP and the STA both supporting a first frequency band and a second frequency band, and the dual-mode transmission mode using the first frequency band to perform uplink transmission and using the second frequency band to perform downlink transmission, or using the second frequency band to perform uplink transmission and using the first frequency band to perform downlink transmission. In this way, the access transmission rate of the WLAN is improved without significantly increasing device hardware costs.

Description

Communication method and system of wireless local area network WLAN

Technical field

The embodiment of the present invention relates to, but is not limited to, a wireless local area network (WLAN), and more specifically relates to a communication method and system of a wireless local area network WLAN.

Background technique

With the development of network communication technology, wireless local area network (WLAN) technology has become more and more integrated into all aspects of people’s lives. Its simple and practical technical characteristics have made more and more network terminal devices use WLAN as their main access network. means.

However, the ensuing problems are becoming more and more obvious. The increasing amount of communication data requires more and more stringent requirements on the bandwidth and transmission quality of wireless local area networks. Taking the 802.11b protocol proposed in 1999 as an example, the transmission rate proposed at that time was 11Mbps (megabits per second), and today's 802.11ac protocol has easily reached a transmission rate above 1Gbps (gigabits per second).

The main means for WLAN technology to increase the transmission rate are generally two: 1. Expand the bandwidth of a single channel; 2. Use space division multiplexing technology to increase the number of MIMO (Multiple-Input Multiple-Output), popular That is to increase the number of antennas. But these two methods will have their own bottlenecks and limits. Taking the extended bandwidth as an example, in the 2.4GHZ (Gigahertz) frequency band, the bandwidth limit is 40MHZ (Mega Hertz), which cannot be further expanded. Even if it is 5.8GHZ, it is already very difficult to expand to above 160MHZ, and at the same time, the disadvantages such as fewer available channels and serious adjacent channel interference are becoming more and more obvious. The use of the method of increasing MIMO will inevitably lead to an increase in hardware cost and volume. This will be a fatal problem for home access terminal equipment that emphasizes cost control and user experience. Secondly, the existence of problems such as multipath effects also makes The number of antennas cannot increase endlessly.

In summary, how to increase the WLAN access rate without significantly increasing the equipment hardware cost will be an urgent problem to be solved.

Summary of the invention

In view of this, the embodiment of the present invention provides a wireless local area network WLAN communication method, which includes: a normal WLAN-associated access point AP and a wireless terminal STA negotiate to enter a dual-mode transmission mode; wherein, the AP and the STA simultaneously support the first A frequency band and a second frequency band; the dual-mode transmission mode is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission; or use the second frequency band for uplink transmission and the first frequency band for downlink transmission.

The embodiment of the present invention also provides a wireless local area network WLAN communication system, including: an access point AP and a wireless terminal STA associated with a normal WLAN; the AP and STA support both a first frequency band and a second frequency band; the AP and STA is set to negotiate to enter dual-mode transmission mode; the dual-mode transmission mode is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission; or use the second frequency band for uplink transmission and the first frequency band for downlink transmission .

The technical solution provided by the embodiment of the present invention improves the access transmission rate of the WLAN on the basis of not significantly increasing the equipment hardware cost.

Other features and advantages of the present invention will be described in the following description, and partly become obvious from the description, or understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the structures specifically pointed out in the specification, claims and drawings.

Description of the drawings

The accompanying drawings are used to provide a further understanding of the technical solution of the present invention, and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention, and do not constitute a limitation to the technical solution of the present invention.

Figure 1 is a schematic diagram of the communication flow of a wireless local area network WLAN in the prior art;

2 is a schematic flowchart of a wireless local area network WLAN communication method provided by an embodiment of the present invention;

3 is a schematic flowchart of a wireless local area network WLAN communication method provided by another embodiment of the present invention;

4 is a schematic diagram of a clock synchronization process in an embodiment of the present invention;

5 is a schematic diagram of the communication flow of a wireless local area network WLAN in an embodiment of the present invention;

6 is a schematic flowchart of a wireless local area network WLAN communication method provided by another embodiment of the present invention;

FIG. 7 is a schematic flowchart of a wireless local area network WLAN communication method according to another embodiment of the present invention;

FIG. 8 is a schematic flowchart of a wireless local area network WLAN communication method provided by another embodiment of the present invention;

FIG. 9 is a schematic flowchart of a frequency band switching in a traffic direction according to an embodiment of the present invention;

FIG. 10 is a schematic flowchart of a frequency band switching in a traffic direction according to another embodiment of the present invention;

FIG. 11 is a schematic flowchart of a frequency band switching in a traffic direction according to another embodiment of the present invention;

FIG. 12 is a schematic flowchart of a frequency band switching in a traffic direction according to another embodiment of the present invention;

FIG. 13 is a schematic flowchart of exiting the dual-mode transmission mode according to an embodiment of the present invention;

FIG. 14 is a schematic flowchart of exiting dual-mode transmission mode according to another embodiment of the present invention;

FIG. 15 is a schematic flowchart of exiting the dual-mode transmission mode according to another embodiment of the present invention;

FIG. 16 is a schematic flowchart of exiting the dual-mode transmission mode according to another embodiment of the present invention;

FIG. 17 is a schematic diagram of a communication flow of a wireless local area network WLAN communication system provided by an embodiment of the present invention;

18 is a schematic flowchart of a wireless local area network WLAN communication method according to another embodiment of the present invention;

19 is a schematic diagram of the communication flow of a wireless local area network WLAN communication system provided by an embodiment of the present invention;

20 is a schematic diagram of the communication flow of a wireless local area network WLAN communication system provided by an embodiment of the present invention;

FIG. 21 is a schematic flowchart of a wireless local area network WLAN communication method according to another embodiment of the present invention;

22 is a schematic diagram of the communication flow of a wireless local area network WLAN communication system provided by an embodiment of the present invention;

FIG. 23 is a schematic structural diagram of a wireless local area network WLAN communication system provided by an embodiment of the present invention;

FIG. 24 is a schematic structural diagram of an AP provided by an embodiment of the present invention;

FIG. 25 is a schematic structural diagram of an STA provided by an embodiment of the present invention.

detailed description

In order to make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other arbitrarily if there is no conflict.

The steps shown in the flowcharts of the drawings can be executed in a computer system such as a set of computer-executable instructions. And, although a logical sequence is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than here.

After analysis, due to the early appearance of WLAN technology, many technologies are indeed unable to adapt to the development speed of today's network technology from the current point of view. For example, WLAN is a typical half-duplex access technology. That is, a single device can only receive or send messages at the same time, but not at the same time. From the current point of view, this is definitely a huge waste of resources, making the theoretical transmission efficiency directly half of the available physical resources.

Specifically, starting from the 802.11n protocol, the legal channels specified by the WLAN access technology are distributed in two frequency bands, 2.4GHZ and 5.8GHZ. Most of the existing network devices support the access of these two frequency bands at the same time, but at the same time, under the existing technology, the two WLAN-related devices use only one frequency band for communication, that is, use 2.4GHZ or respectively. 5.8GHZ frequency band, which means that at least half of the physical resources are in an idle state. For example, as shown in Figure 1, although AP (Access Point) and STA (station, wireless terminal) both support 2.4GHZ and 5.8GHZ frequency bands, they only use 2.4G half-duplex transmission, and the 5G frequency band is always idle. The use of network equipment is a great waste of resources.

The idea of the embodiment of the present invention is to propose a solution based on the status quo that such physical resources are idle. That is, based on the use of idle frequency bands, without increasing the equipment hardware cost, two WLAN associated devices simultaneously use different frequency bands (dual-mode) for wireless communication in different traffic directions.

FIG. 2 is a schematic flowchart of a wireless local area network WLAN communication method provided by an embodiment of the present invention. As shown in Figure 2, the method includes:

Step 201: The access point AP and the wireless terminal STA associated with the normal WLAN negotiate to enter the dual-mode transmission mode;

Wherein, the AP and STA support the first frequency band and the second frequency band at the same time;

The dual-mode transmission mode is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission; or use the second frequency band for uplink transmission and the first frequency band for downlink transmission.

Wherein, the AP and the STA negotiate to enter the dual-mode transmission mode, including:

After the AP and the STA perform a normal WLAN association in the first frequency band, the AP obtains the first capability information of the STA; the first capability information includes whether the STA supports the second frequency band, and the specific information supported by the STA Channel, bandwidth range, and wireless area code, the STA has currently associated status;

The AP judges whether the capabilities of both parties match according to the first capability information, and when they match, performs normal WLAN association with the STA in the second frequency band, and negotiates to determine the frequency band and bandwidth value of each traffic direction;

The AP and the STA perform clock synchronization;

Alternatively, after the AP and the STA perform a normal WLAN association in the first frequency band, the STA obtains second capability information of the AP; the second capability information includes whether the AP supports the second frequency band, and the AP supports The specific channel, bandwidth range, and wireless area code of the AP, and the current status of the AP;

The STA judges whether the capabilities of the two parties match according to the second capability information, and when they match, performs normal WLAN association with the AP in the second frequency band, and negotiates to determine the frequency band and bandwidth value of each traffic direction;

The STA and the AP perform clock synchronization;

Alternatively, after the AP and the STA perform a normal WLAN association in the second frequency band, the AP obtains the third capability information of the STA; the third capability information includes whether the STA supports the first frequency band, and the STA supports The specific channel, bandwidth range, and wireless area code of the STA, and the current association status of the STA;

The AP judges whether the capabilities of both parties match according to the third capability information, and when they match, performs normal WLAN association with the STA in the first frequency band, and negotiates to determine the frequency band and bandwidth value of each traffic direction;

The AP and the STA perform clock synchronization;

Or, after the AP and the STA perform a normal WLAN association in the second frequency band, the STA obtains fourth capability information of the AP; the fourth capability information includes whether the AP supports the first frequency band, and the AP supports The specific channel, bandwidth range, and wireless area code of the STA, and the current association status of the STA;

The STA judges whether the capabilities of both parties match according to the fourth capability information, and when they match, performs normal WLAN association with the AP in the first frequency band, and negotiates to determine the frequency band and bandwidth value of each traffic direction;

The STA and AP perform clock synchronization.

Wherein, after the AP and the STA negotiate to enter the dual-mode transmission mode, the method further includes:

When the dual-mode transmission mode is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission, the STA uses the first frequency band for uplink transmission, and the AP uses the second frequency band for downlink transmission;

Alternatively, when the dual-mode transmission mode is to use the second frequency band for uplink transmission and the first frequency band for downlink transmission, the STA uses the second frequency band for uplink transmission, and the AP uses the first frequency band for downlink transmission.

Among them, the method also includes:

When the first frequency band and/or the second frequency band fail, exit the dual-mode transmission mode or switch the frequency band of the traffic direction.

Wherein, the frequency band switching of the traffic direction includes:

When the STA uses the first frequency band for uplink transmission and detects an uplink transmission failure, use the second frequency band to send a traffic direction adjustment request message to the AP;

The AP detects whether the data traffic corresponding to the second frequency band exceeds the alarm threshold, and when it does not exceed the alarm threshold, uses the second frequency band to reply to the STA a response message agreeing to adjust the direction;

The STA switches to use the second frequency band for uplink transmission, and the AP switches to use the first frequency band for downlink transmission;

Or, when the STA uses the second frequency band for uplink transmission and detects an uplink transmission failure, use the first frequency band to send a traffic direction adjustment request message to the AP;

The AP detects whether the data traffic corresponding to the first frequency band exceeds the alarm threshold, and when it does not exceed the alarm threshold, uses the first frequency band to reply to the STA a response message agreeing to adjust the direction;

The STA switches to use the first frequency band for uplink transmission, and the AP switches to use the second frequency band for downlink transmission;

Or, when the AP uses the first frequency band for downlink transmission and detects a downlink transmission failure, it uses the second frequency band to send a traffic direction adjustment request message to the STA;

The STA detects whether the data traffic corresponding to the second frequency band exceeds the alarm threshold, and when it does not exceed the alarm threshold, uses the second frequency band to reply to the AP with a response message agreeing to adjust the direction;

The AP switches to use the second frequency band for downlink transmission, and the STA switches to use the first frequency band for uplink transmission;

Or, when the AP uses the second frequency band for downlink transmission and detects a downlink transmission failure, it uses the first frequency band to send a traffic direction adjustment request message to the STA;

The STA detects whether the data traffic corresponding to the first frequency band exceeds an alarm threshold, and when it does not exceed the alarm threshold, uses the first frequency band to reply to the AP with a response message agreeing to adjust the direction;

The AP switches to use the first frequency band for downlink transmission, and the STA switches to use the second frequency band for uplink transmission;

Wherein, the request message for adjusting the flow direction and the response message for agreeing to adjust the direction are transmitted using high-priority packets.

Wherein, the exiting the dual-mode transmission mode includes:

When the STA uses the first frequency band for uplink transmission and detects an uplink transmission failure, use the second frequency band to send a failure warning message to the AP;

After receiving the failure warning message, the AP uses the second frequency band to send a request to exit the dual-mode transmission mode to the STA;

After the STA receives the request to exit the dual-mode transmission mode, it disconnects the association with the first frequency band of the AP;

Or, when the STA uses the second frequency band for uplink transmission and detects an uplink transmission failure, use the first frequency band to send a failure warning message to the AP;

After receiving the fault alarm message, the AP uses the first frequency band to send a request to exit the dual-mode transmission mode to the STA;

After receiving the request to exit the dual-mode transmission mode, the STA disconnects the association with the second frequency band of the AP;

Or, when the AP uses the first frequency band for downlink transmission and detects a downlink transmission failure, it uses the second frequency band to send a failure warning message to the STA;

After receiving the failure warning message, the STA uses the second frequency band to send a request to exit the dual-mode transmission mode to the AP;

After receiving the request to exit the dual-mode transmission mode, the AP disconnects the association with the first frequency band of the STA;

Or, when the AP uses the second frequency band for downlink transmission and detects a downlink transmission failure, it uses the first frequency band to send a failure warning message to the STA;

After receiving the fault alarm message, the STA uses the first frequency band to send a request to exit the dual-mode transmission mode to the AP;

After receiving the request to exit the dual-mode transmission mode, the AP disconnects the association with the second frequency band of the STA.

Wherein, after exiting the dual-mode transmission mode, the method further includes:

After the AP and the STA disconnect the association of the first frequency band, initiate a re-association of the first frequency band, and when the re-association of the first frequency band is successful, renegotiate to enter the dual-mode transmission mode;

Alternatively, after the AP and the STA are disconnected from the second frequency band, re-association of the second frequency band is initiated, and after the re-association of the second frequency band is successful, renegotiate to enter the dual-mode transmission mode.

Wherein, when there are multiple STAs, the dual-mode transmission modes negotiated by the AP and the multiple STAs are the same.

Wherein, after the AP and the STA negotiate to enter the dual-mode transmission mode, the method includes:

The AP and STA perform clock synchronization periodically.

Wherein, the first frequency band is a 2.4G frequency band, and the second frequency band is a 5.8G frequency band;

Alternatively, the first frequency band is a 5.8G frequency band, and the second frequency band is a 2.4G frequency band.

FIG. 3 is a schematic flowchart of a wireless local area network WLAN communication method according to another embodiment of the present invention. As shown in Figure 3, the method includes:

Step 301: After the access point AP and the wireless terminal STA perform normal WLAN association in the first frequency band, the AP obtains the first capability information of the STA;

Wherein, the first capability information includes whether the STA supports the second frequency band, the specific channel, bandwidth range, and wireless area code supported by the STA, the current association status of the STA, and so on.

In this embodiment, the first frequency band is the 2.4G frequency band and the second frequency band is the 5.8G frequency band as an example for description. Of course, it is also possible that the first frequency band is a 5.8G frequency band, and the second frequency band is a 2.4G frequency band, and there is no specific limitation.

Specifically, when AP (Access Point, access point) and STA (station, wireless terminal) are in a normal association state (2.4G or 5.8G frequency band), the local device AP actively sends to the opposite device STA The detection request requests the capability information of the STA; after receiving the detection request, the STA responds to its own device capability information, including information such as the supported frequency band, channel, bandwidth, and associated devices.

Normally, most APs and terminal devices on the market currently support dual-mode frequency bands (2.4GHZ and 5GHZ). Therefore, in this embodiment, 2.4GHZ is taken as the normal association of the first frequency band as an example. The specific normal association and work flow are outside the scope of the present invention, and will not be described here.

Step 302: The AP judges whether the capabilities of the two parties match according to the first capability information, and when they match, they perform normal WLAN association with the STA in the second frequency band, and negotiate to determine the frequency band and bandwidth value of each traffic direction, and Perform clock synchronization;

Specifically, after the capability information supported by the two associated devices match, the free frequency band of the AP is associated with the corresponding frequency band of the STA. Subsequently, the AP and the STA conduct a negotiation process to negotiate the traffic transmission direction of the first frequency band and the second frequency band and the bandwidth value in each direction.

Among them, the specific negotiation process may be that the AP calculates an appropriate flow direction and bandwidth value according to the actual situation of its own traffic and the bandwidth of the AP and the opposite STA, and informs the STA through a message. If the STA supports the parameters sent by the AP (flow direction and bandwidth value), it will reply to the AP with a successfully negotiated message, and the negotiation is successful; if the STA does not support the parameters sent by the AP (flow direction and bandwidth value), it can reply to the AP that the negotiation failed The negotiation is unsuccessful or the AP calculates a new parameter again to initiate the negotiation; or, the STA calculates an appropriate flow direction and bandwidth based on the actual traffic situation of its own and the bandwidth of the STA and the opposite AP Value, and inform the AP through a message to perform a second negotiation and so on. This embodiment does not specifically limit the negotiation process.

After the negotiation is successful, the negotiation result is stored in the database of the AP and the STA until the end of the associated transmission process.

Specifically, during the negotiation process between AP and STA, the following parameters are mainly considered for negotiation:

1. AP real-time traffic load status, mainly need to consider the existing traffic load direction in the AP equipment, and the size of the upstream and downstream traffic;

2. The service type of the user's STA equipment, for different actual service types such as video, voice, and download services, and different service traffic load conditions;

3. The interference of different wireless channels in the environment, including factors such as the size and direction of interference traffic of other environmental equipment.

It should be noted that the above parameters are only examples listed in this embodiment, and in the actual technical implementation process, they are by no means limited to the above negotiation parameters. Rather, all parameters and factors that may affect the direction of the negotiated flow of the device are included in the scope of this embodiment.

For example, in this embodiment, the negotiation result is that the first frequency band is used as the uplink transmission frequency band and the second frequency band is used as the downlink transmission frequency band as an example for description. Of course, the negotiation result can also be to use the second frequency band as the uplink transmission frequency band and the first frequency band as the downlink transmission frequency band, and there is no specific restriction.

After the dual bands of the AP and STA devices are associated with each other, the AP periodically sends clock synchronization signals to complete the clock synchronization between the AP and the STA. During the subsequent message transmission process, the AP maintains the clock synchronization state with all STAs. At this time, the AP and STA have entered the dual mode transmission mode, and subsequent messages will use one frequency band (for example, 2.4G) for uplink transmission, and another frequency band (5.8G) for downlink transmission.

Specifically, as shown in Figure 4, when the AP and STA dual-mode frequency bands are successfully associated, and information such as traffic direction and bandwidth are negotiated successfully. The AP proactively sends out a clock synchronization message, and the STA responds with a clock synchronization confirmation message after receiving it. It is also possible for the STA to request the AP for clock synchronization. After receiving the clock synchronization request, the AP sends a clock synchronization message, and the STA responds with an acknowledgement message after receiving it. This embodiment does not limit the specific clock synchronization process. At this time, the system composed of AP and STA completes clock synchronization, and then the dual-mode frequency band can be used to simultaneously transmit data packets. In the subsequent transmission process, the AP will periodically send clock synchronization messages to the STA to maintain the clock synchronization of the entire system until the end of the transmission process.

For example, in this embodiment, since the messages between the AP and the STA are simultaneously transmitted through the 5.8G and 2.4G dual frequency bands, due to the multipath effect of the wireless transmission itself, the delay of the message transmission changes dynamically. In order to improve the accuracy of message processing by the system, it is necessary for the entire system to have a unified clock for rearranging out-of-sequence messages. Therefore, in this embodiment, the AP can actively send the clock synchronization signal through 2.4 GHz, and when the STA receives the synchronization signal, the 5.8 GHz frequency band will reply to the confirmation message. It is also possible to select a frequency band with a light load to transmit the clock synchronization message according to the load condition of a specific frequency band, which is not specifically limited in this embodiment.

When the clock of the entire system is synchronized for the first time, it is considered that the entire system enters the dual-mode transmission mode, and the dual-mode simultaneous data transmission is started. In the subsequent normal transmission of the system, the AP will periodically send a clock synchronization signal, and this period is called the clock synchronization period. At the same time, considering that the system is in normal operation, when the transmission data is large, there will be link congestion, and the clock synchronization message should be sent with high priority to ensure that the system clock is always synchronized.

Step 303: The AP uses the second frequency band for downlink transmission, and the STA uses the first frequency band for uplink transmission;

In this embodiment, as shown in FIG. 5, the dual-mode transmission mode determined according to step 302 is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission. Therefore, in this step, the AP uses the second frequency band. The frequency band is used for downlink transmission, and the STA uses the first frequency band for uplink transmission.

If the dual-mode transmission mode determined in step 302 is to use the second frequency band for uplink transmission and the first frequency band for downlink transmission, the STA uses the second frequency band for uplink transmission, and the AP uses the first frequency band for uplink transmission. Downlink transmission.

During the AP and STA data transmission process, the transmission direction of the flow will be dynamically switched according to the actual transmission flow situation, so as to achieve the optimal configuration and utilization of resources.

Step 304: When a failure occurs in the first frequency band and/or the second frequency band, exit the dual-mode transmission mode or perform frequency band switching in the direction of the traffic.

Specifically, when an AP or STA fails in a certain frequency band (2.4G or 5.8G), the malfunctioning device uses the frequency band that is still working normally to send a failure alarm to the peer device, notifying the peer to switch the frequency band and traffic direction , Or exit the dual-mode transmission mode directly;

When an AP or STA fails in a certain frequency band (2.4G or 5.8G), its peer device can also use another normal frequency band to determine whether the wlan ack message is normally received to determine the failure situation; actively request the peer to perform the frequency band And the flow direction switch, or directly exit the dual-mode transmission mode.

FIG. 6 is a schematic flowchart of a wireless local area network WLAN communication method provided by another embodiment of the present invention. As shown in Figure 6, the method includes:

Step 601: After the access point AP and the wireless terminal STA perform normal WLAN association in the first frequency band, the STA obtains second capability information of the AP;

Wherein, the second capability information includes whether the AP supports the second frequency band, the specific channel, bandwidth range, and wireless area code supported by the AP, the current association status of the AP, and so on.

Normally, most APs and terminal devices on the market currently support dual-mode frequency bands (2.4GHZ and 5GHZ). Therefore, in this embodiment, 2.4GHZ is taken as an example of normal association in the first frequency band. The specific normal association and work flow are outside the scope of the present invention and will not be described here.

Wherein, the STA acquiring the second capability information of the AP includes:

The STA sends a detection request to the AP, requesting the AP's capability information. After receiving the detection request, the AP responds to its own device capability information, including information such as supported frequency bands, channels, bandwidth, and associated devices.

Specifically, in this embodiment, the STA actively initiates a request, and uses the message interaction of the first frequency band to obtain relevant necessary information on the AP side, including but not limited to the following:

Whether the AP supports the second frequency band;

The specific channel supported by the AP;

Bandwidth range supported by the AP;

Supported wireless area codes;

The AP currently has associated equipment status, etc.

Step 602: The STA judges whether the capabilities of the two parties match according to the second capability information. When they match, they perform normal WLAN association with the AP in the second frequency band, and negotiate to determine the frequency band and bandwidth value of each traffic direction, and Perform clock synchronization;

Specifically, after the STA obtains the AP's second capability information through the first frequency band communication, it determines whether it can continue to associate with the AP's second frequency band. After information analysis, it is confirmed that it can be associated. Then the STA actively initiates an association request for the second frequency band to the AP. After the AP responds to the association request, the association is completed through a normal authentication process.

Then, after the second frequency band is successfully associated, the STA negotiates the traffic direction, bandwidth value and other parameters with the AP. The specific negotiation process can be that the STA calculates according to the actual situation of its own traffic and the bandwidth of the STA and the opposite AP. A suitable flow direction and bandwidth value are given, and the AP is notified through a message. If the AP supports the parameters (flow direction and bandwidth value) sent by the STA, it will reply to the STA with a successfully negotiated message, and the negotiation is successful; if the AP does not support the parameters (flow direction and bandwidth value) sent by the STA, it can reply to the STA that the negotiation failed If the negotiation is unsuccessful, or the STA calculates a new parameter again to initiate the negotiation; or, the AP calculates an appropriate traffic direction and bandwidth based on the actual traffic situation of its own and the bandwidth of the AP and the opposite STA Value, and notify the STA through a message to perform a second negotiation, etc. The present embodiment does not specifically limit the negotiation process.

Specifically, during the negotiation process between the STA and the AP, the following parameters are mainly considered for negotiation:

Specifically, when the AP and STA dual-mode frequency bands are successfully associated, and the traffic direction and bandwidth are all negotiated successfully. The AP can take the initiative to send out a clock synchronization message, and the STA will reply with a confirmation message after receiving it. It is also possible for the STA to request the AP for clock synchronization. After receiving the clock synchronization request, the AP sends a clock synchronization message, and the STA responds with an acknowledgement message after receiving it. This embodiment does not limit the specific clock synchronization process. At this time, the system composed of AP and STA completes clock synchronization, and then the dual-mode frequency band can be used to simultaneously transmit data packets.

In the subsequent transmission process, the AP will periodically send clock synchronization messages to the STA to maintain the clock synchronization of the entire system until the end of the transmission process.

Step 603: The AP uses the second frequency band for downlink transmission, and the STA uses the first frequency band for uplink transmission;

In this embodiment, as shown in FIG. 5, the dual-mode transmission mode determined according to step 602 is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission. Therefore, in this step, the AP uses the second frequency band. The frequency band is used for downlink transmission, and the STA uses the first frequency band for uplink transmission.

If the dual-mode transmission mode determined in step 602 is to use the second frequency band for uplink transmission and the first frequency band for downlink transmission, the STA uses the second frequency band for uplink transmission, and the AP uses the first frequency band for uplink transmission. Downlink transmission.

Step 604: When a failure occurs in the first frequency band and/or the second frequency band, exit the dual-mode transmission mode or perform frequency band switching of the traffic direction.

FIG. 7 is a schematic flowchart of a wireless local area network WLAN communication method provided by another embodiment of the present invention. As shown in Figure 7, the method includes:

Step 701: After the access point AP and the wireless terminal STA perform normal WLAN association in the second frequency band, the AP obtains the third capability information of the STA;

Wherein, the third capability information includes whether the STA supports the first frequency band, the specific channel, bandwidth range, and wireless area code supported by the STA, the current association status of the STA, and so on.

Normally, most APs and terminal devices on the market currently support dual-mode frequency bands (2.4GHZ and 5GHZ). Therefore, in this embodiment, 5.8GHZ is taken as an example of normal association of the second frequency band. The specific normal association and work flow are outside the scope of the present invention and will not be described here.

Step 702: The AP judges whether the capabilities of both parties match according to the third capability information. When they match, they perform normal WLAN association with the STA in the first frequency band, and negotiate to determine the frequency band and bandwidth value of each traffic direction, and Perform clock synchronization;

After the dual frequency bands of the AP and STA devices are associated with each other, the AP periodically sends clock synchronization signals to complete the clock synchronization between the AP and the STA. In the subsequent message transmission process, the AP maintains the clock synchronization state with all STAs. At this time, the AP and STA have entered the dual mode transmission mode, and subsequent messages will use one frequency band (for example, 2.4G) for uplink transmission, and another frequency band (5.8G) for downlink transmission.

Specifically, when the AP and STA dual-mode frequency bands are successfully associated, and the traffic direction and bandwidth are all negotiated successfully. The AP proactively sends out a clock synchronization message, and the STA responds with a confirmation message after receiving it. It is also possible for the STA to request the AP for clock synchronization. After receiving the clock synchronization request, the AP sends a clock synchronization message, and the STA responds with an acknowledgement message after receiving it. This embodiment does not limit the specific clock synchronization process. At this time, the system composed of AP and STA completes clock synchronization, and then the dual-mode frequency band can be used to simultaneously transmit data packets. In the subsequent transmission process, the AP will periodically send clock synchronization messages to the STA to maintain the clock synchronization of the entire system until the end of the transmission process.

Step 703: The AP uses the second frequency band for downlink transmission, and the STA uses the first frequency band for uplink transmission;

Wherein, in this embodiment, as shown in FIG. 5, the dual-mode transmission mode determined according to step 702 is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission. Therefore, in this step, the AP uses The second frequency band is used for downlink transmission, and the STA uses the first frequency band for uplink transmission.

If the dual-mode transmission mode determined in step 702 is to use the second frequency band for uplink transmission and the first frequency band for downlink transmission, the STA uses the second frequency band for uplink transmission, and the AP uses the first frequency band for uplink transmission. Downlink transmission.

Step 704: When a failure occurs in the first frequency band and/or the second frequency band, exit the dual-mode transmission mode or perform frequency band switching of the traffic direction.

FIG. 8 is a schematic flowchart of a wireless local area network WLAN communication method according to another embodiment of the present invention. As shown in Figure 8, the method includes:

Step 801: After the access point AP and the wireless terminal STA perform normal WLAN association in the second frequency band, the STA obtains fourth capability information of the AP;

Wherein, the fourth capability information includes whether the AP supports the first frequency band, the specific channel, bandwidth range, and wireless area code supported by the AP, the current association status of the STA, and so on.

Normally, most APs and terminal devices on the market currently support dual-mode frequency bands (2.4GHZ and 5GHZ). Therefore, in this embodiment, the normal association with 5.8 GHz as the second frequency band is taken as an example. The specific normal association and work flow are outside the scope of the present invention, and will not be described here.

Wherein, the STA acquiring the fourth capability information of the AP includes:

Specifically, in this embodiment, the STA actively initiates a request, and uses the message interaction of the second frequency band to obtain relevant necessary information on the AP side, including but not limited to the following:

Whether the AP supports the first frequency band;

The specific channel supported by the AP;

Bandwidth range supported by the AP;

Supported wireless area codes;

The AP currently has associated equipment status, etc.

Step 802: The STA judges whether the capabilities of both parties match according to the fourth capability information. When they match, they perform normal WLAN association with the AP in the first frequency band, and negotiate to determine the frequency band and bandwidth value of each traffic direction, and Perform clock synchronization;

Specifically, after the STA obtains the fourth capability information of the AP through the first frequency band communication, it determines whether it can continue to associate with the first frequency band of the AP. After information analysis, it is confirmed that it can be associated. The STA actively initiates an association request for the first frequency band to the AP. After the AP responds to the association request, the association is completed through a normal authentication process.

Then, after the first frequency band is successfully associated, the STA negotiates the traffic direction, bandwidth value and other parameters with the AP. The specific negotiation process can be that the STA calculates according to the actual situation of its own traffic and the bandwidth of the STA and the opposite AP. A suitable flow direction and bandwidth value are given, and the AP is notified through a message. If the AP supports the parameters (flow direction and bandwidth value) sent by the STA, it will reply to the STA with a successfully negotiated message, and the negotiation is successful; if the AP does not support the parameters (flow direction and bandwidth value) sent by the STA, it can reply to the STA that the negotiation failed If the negotiation is unsuccessful, or the STA calculates a new parameter again to initiate the negotiation; or, the AP calculates an appropriate traffic direction and bandwidth based on the actual traffic situation of its own and the bandwidth of the AP and the opposite STA Value, and notify the STA through a message to perform a second negotiation, etc. The present embodiment does not specifically limit the negotiation process.

Specifically, when the AP and STA dual-mode frequency bands are successfully associated, and information such as traffic direction and bandwidth are negotiated successfully. The AP can take the initiative to send out a clock synchronization message, and the STA will reply with a confirmation message after receiving it. It is also possible for the STA to request the AP for clock synchronization. After receiving the clock synchronization request, the AP sends a clock synchronization message, and the STA responds with an acknowledgement message after receiving it. This embodiment does not limit the specific clock synchronization process. At this time, the system composed of AP and STA completes clock synchronization, and then the dual-mode frequency band can be used to simultaneously transmit data packets.

Step 803: The AP uses the second frequency band for downlink transmission, and the STA uses the first frequency band for uplink transmission;

In this embodiment, as shown in FIG. 5, the dual-mode transmission mode determined according to step 802 is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission. Therefore, in this step, the AP uses the second frequency band. The frequency band is used for downlink transmission, and the STA uses the first frequency band for uplink transmission.

If the dual-mode transmission mode determined in step 802 is to use the second frequency band for uplink transmission and the first frequency band for downlink transmission, the STA uses the second frequency band for uplink transmission, and the AP uses the first frequency band for uplink transmission. Downlink transmission.

Step 804: When a failure occurs in the first frequency band and/or the second frequency band, exit the dual-mode transmission mode or perform frequency band switching of the traffic direction.

The technical solutions provided in the foregoing embodiments utilize the existing technology to increase the access transmission rate of the WLAN technology on the basis of not significantly increasing the equipment hardware cost. Compared with the existing method of increasing the transmission rate, it not only overcomes the reduction of available channels and the increase of adjacent channel interference caused by bandwidth expansion; it also does not appear to increase the equipment cost and volume caused by the increase of the number of antennas.

Another embodiment, on the basis of the above embodiment, elaborates in detail the specific process of performing frequency band switching of the traffic direction when the first frequency band and/or the second frequency band fails.

In this embodiment, it is assumed that the AP and the STA are in a normal working state in the dual-mode transmission mode, and the first frequency band is used for 2.4G to transmit uplink data, and the second frequency band is used for 5.8G to transmit downlink data. The negotiated bandwidth of 2.4G is 130Mbps, and the negotiated bandwidth of 5.8G is 867Mbps. Of course, it is also possible to use the second frequency band to transmit uplink data for 2.4G, and use the first frequency band to transmit downlink data for 5.8G, without any specific restrictions.

As shown in Figure 9, the specific process includes:

Step 901: When the STA uses the first frequency band for uplink transmission and detects an uplink transmission failure, the STA uses the second frequency band to send a traffic direction adjustment request message to the AP;

Among them, the uplink transmission failure refers to the problem that the STA detects that the uplink data packet suddenly increases, exceeds the congestion alarm threshold, and so on, which causes the uplink data to be unable to be transmitted.

Specifically, the STA may use the second frequency band to send the traffic direction adjustment request message (Direction adjustment Request).

Step 902: After receiving the traffic direction adjustment request message, the AP detects whether the data traffic corresponding to the second frequency band exceeds the alarm threshold, and when it does not exceed the alarm threshold, uses the second frequency band to reply to the STA a response message agreeing to the direction of adjustment;

Specifically, in this embodiment, after receiving the request, the AP detects the current data traffic in the second frequency band, and if the traffic does not exceed the alarm threshold reported by the STA (which can be carried in the traffic direction adjustment request message), it agrees to adjust the direction Request, reply Ack OK message, otherwise reply NOK.

After the STA receives the Ack OK message, the AP and the STA enter the protection time (Protect Time). The data transmitted by both parties is suspended, waiting for the completion of the adjustment.

Step 903: The STA switches to use the second frequency band for uplink transmission, and the AP switches to use the first frequency band for downlink transmission.

At this time, the traffic transmission direction between the AP and the STA is switched, the second frequency band is used to transmit uplink data, and the first frequency band is used to transmit downlink data. At this time, the upstream traffic can be transmitted using the negotiated bandwidth of 867Mbps, and the congestion alarm is removed.

In this embodiment, there may be but not limited to the following recommended configuration items:

1. By default, 5.8G downlink and 2.4G uplink are preferred, because user data usually has a large downlink traffic, and the negotiated bandwidth of 5G is much larger than the negotiated bandwidth of 2.4G;

2. Congestion threshold = channel negotiation rate * 70% (configurable);

3. Redirection protection mechanism: To prevent frequent traffic redirection from causing network jitter, you can configure the redirection protection time (for example, 90 seconds). Only one adjustment of flow direction can be completed within this time;

4. Direction adjustment request (Direction adjustment Request) and response reply (Ack) should be transmitted in high-priority packets.

In this embodiment, it is assumed that the AP and the STA are in the normal working state of the dual-mode transmission mode, the first frequency band is used for 2.4G to transmit downlink data, and the second frequency band is used for 5.8G to transmit uplink data. The negotiated bandwidth of 2.4G is 130Mbps, and the negotiated bandwidth of 5.8G is 867Mbps. Of course, it is also possible to use the first frequency band to transmit uplink data for 2.4G, and use the second frequency band to transmit downlink data for 5.8G, without specific restrictions.

As shown in Figure 10, the specific process includes:

Step 1001: When an STA uses the second frequency band for uplink transmission and detects an uplink transmission failure, the STA uses the first frequency band to send a traffic direction adjustment request message to the AP;

Specifically, the STA may use the first frequency band to send the traffic direction adjustment request message (Direction adjustment Request).

Step 1002: After receiving the traffic direction adjustment request message, the AP detects whether the data traffic corresponding to the first frequency band exceeds an alarm threshold, and when it does not exceed the alarm threshold, uses the first frequency band to reply to the STA a response message agreeing to adjust the direction;

Specifically, in this embodiment, after receiving the request, the AP detects the current data traffic in the first frequency band, and if the traffic does not exceed the alarm threshold reported by the STA (which can be carried in the traffic direction adjustment request message), it agrees to adjust the direction Request, reply Ack OK message, otherwise reply NOK.

Step 1003: The STA switches to use the first frequency band for uplink transmission, and the AP switches to use the second frequency band for downlink transmission.

At this time, the traffic transmission direction between the AP and the STA is switched, the first frequency band is used to transmit uplink data, and the second frequency band is used to transmit downlink data.

1. For specific services, such as live broadcasting, 2.4G downlink and 5.8G uplink can be preferentially used by default, because user data usually has a large uplink traffic, and the negotiated bandwidth of 5G is much larger than the negotiated bandwidth of 2.4G;

2. Congestion threshold = channel negotiation rate * 70% (configurable);

As shown in Figure 11, the specific process includes:

Step 1101: When the AP uses the first frequency band for downlink transmission and detects a downlink transmission failure, it uses the second frequency band to send a traffic direction adjustment request message to the STA;

Among them, the downlink transmission failure refers to a problem that the AP detects a failure in the downlink frequency band, etc., which causes the failure to send downlink packets normally. For example, in this embodiment, when the 2.4G module of the AP fails, the downlink message cannot be sent normally.

Specifically, the AP can use the second frequency band 5.8G to send the traffic direction adjustment request message (Direction adjustment Request).

Step 1102: After receiving the traffic direction adjustment request message, the STA detects whether the data traffic corresponding to the second frequency band exceeds an alarm threshold, and when it does not exceed the alarm threshold, uses the second frequency band to reply to the AP with a response message agreeing to adjust the direction;

Specifically, in this embodiment, after receiving the request, the STA detects the current data traffic in the first frequency band, and if the traffic does not exceed the alarm threshold reported by the AP (which can be carried in the traffic direction adjustment request message), it agrees to adjust the direction Request, reply Ack OK message, otherwise reply NOK.

After the AP receives the Ack OK message, the AP and the STA enter the protection time (Protect Time). The data transmitted by both parties is suspended, waiting for the completion of the adjustment.

Step 1103: The STA switches to use the first frequency band for uplink transmission, and the AP switches to use the second frequency band for downlink transmission.

2. Congestion threshold = channel negotiation rate * 70% (configurable);

In this embodiment, it is assumed that the AP and STA are in the normal working state of the dual-mode transmission mode, and the first frequency band is used for 2.4G to transmit uplink data, and the second frequency band is used for 5.8G to transmit downlink data. The negotiated bandwidth of 2.4G is 130Mbps, and the negotiated bandwidth of 5.8G is 867Mbps. Of course, the first frequency band can also be used to transmit downlink data at 2.4G, and the second frequency band can be used to transmit uplink data at 5.8G, without any specific restrictions.

As shown in Figure 12, the specific process includes:

Step 1201: When the AP uses the second frequency band for downlink transmission and detects a downlink transmission failure, it uses the first frequency band to send a traffic direction adjustment request message to the STA;

Among them, the downlink transmission failure refers to a problem that the AP detects a failure in the downlink frequency band, etc., which causes the failure to send downlink packets normally. For example, in this embodiment, when the AP's 5.8G module fails, the downlink message cannot be sent normally.

Specifically, the AP may use the first frequency band 2.4G to send the traffic direction adjustment request message (Direction adjustment Request).

Step 1202: After receiving the request message for adjusting the flow direction, the STA detects whether the data flow corresponding to the second frequency band exceeds the alarm threshold, and when it does not exceed the alarm threshold, uses the first frequency band to reply to the AP with a response message agreeing to adjust the direction;

Step 1203: The STA switches to use the second frequency band for uplink transmission, and the AP switches to use the first frequency band for downlink transmission.

At this time, the traffic transmission direction between the AP and the STA is switched, the second frequency band is used to transmit uplink data, and the first frequency band is used to transmit downlink data.

1. For specific services, such as live broadcasts, 2.4G downlink and 5.8G uplink can be preferred by default, because user data usually has a large uplink traffic, and the negotiated bandwidth of 5G is much larger than the negotiated bandwidth of 2.4G;

2. Congestion threshold = channel negotiation rate * 70% (configurable);

Another embodiment, on the basis of the above embodiment, elaborates in detail the specific process of exiting the dual-mode transmission mode when the first frequency band and/or the second frequency band fails.

In this embodiment, it is assumed that the AP and the STA are in a normal working state in the dual-mode transmission mode, and the first frequency band is used for 2.4G to transmit uplink data, and the second frequency band is used for 5.8G to transmit downlink data. The negotiated bandwidth of 2.4G is 130Mbps, and the negotiated bandwidth of 5.8G is 867Mbps. Of course, the first frequency band can also be used to transmit downlink data at 2.4G, and the second frequency band can be used to transmit uplink data at 5.8G, without any specific restrictions.

As shown in Figure 13, the specific process includes:

Step 1301: When the STA uses the first frequency band for uplink transmission and detects an uplink transmission failure, it uses the second frequency band to send a failure warning message to the AP;

For example, in this embodiment, the STA detects that the uplink data packet suddenly increases and exceeds the congestion alarm threshold; the STA immediately sends a fault alarm message to the AP.

Step 1302: After receiving the fault alarm message, the AP uses the second frequency band to send a request to exit the dual-mode transmission mode to the STA;

Step 1303: After receiving the request to exit the dual-mode transmission mode, the STA disconnects the association with the first frequency band of the AP.

At this time, the STA and AP exit the dual-mode transmission mode and return to the single-mode transmission mode, for example, use the second frequency band to continue traditional single-mode transmission.

In another embodiment, on the basis of the previous embodiment, when the STA and the AP disconnect the first frequency band, they initiate the re-association of the first frequency band, and when the re-association of the first frequency band is successful , Renegotiate to enter dual-mode transmission mode.

Specifically, for example, in this embodiment, since the STA actively disconnects the 2.4G frequency band association with the AP, it can then initiate a 2.4G re-association; after the STA and the AP’s 2.4G re-association succeeds, the re-negotiation process is performed. The process is the same as the negotiation process in the above embodiment, and the description is not repeated here; if the negotiation succeeds, the STA and the AP re-enter the dual-mode transmission mode. If the negotiation is unsuccessful, the normal 5.8G single-mode transmission mode is used, and no fault repair attempts are made.

As shown in Figure 14, the specific process includes:

Step 1401: When the STA uses the second frequency band for uplink transmission and detects an uplink transmission failure, it uses the first frequency band to send a failure warning message to the AP;

Step 1402: After receiving the fault alarm message, the AP uses the first frequency band to send a request to exit the dual-mode transmission mode to the STA;

Step 1403: After receiving the request to exit the dual-mode transmission mode, the STA disconnects the association with the second frequency band of the AP.

At this time, the STA and AP exit the dual-mode transmission mode and return to the single-mode transmission mode, for example, use the first frequency band to continue traditional single-mode transmission.

In another embodiment, on the basis of the previous embodiment, after the STA and the AP disconnect the second frequency band, they can initiate the re-association of the second frequency band. When the re-association of the second frequency band is successful Then, renegotiate to enter the dual-mode transmission mode.

Specifically, for example, in this embodiment, because the STA actively disconnects from the AP's 5.8G frequency band, it can then initiate a 5.8G re-association; after the STA successfully re-associates with the AP's 5.8G frequency band, a re-negotiation process is performed. The process is the same as the negotiation process in the above embodiment, and the description is not repeated here; if the negotiation succeeds, the STA and the AP re-enter the dual-mode transmission mode. If the negotiation is unsuccessful, the normal 2.4G single-mode transmission mode will be used, and no fault repair attempts will be made.

As shown in Figure 15, the specific process includes:

Step 1501: When the AP uses the first frequency band for downlink transmission and detects a downlink transmission failure, it uses the second frequency band to send a failure warning message to the STA;

Among them, the downlink transmission failure refers to the problem that the AP detects a failure in the downlink frequency band, etc., which causes the downlink message to be unable to be sent normally.

For example, in this embodiment, when the 2.4G module of the AP fails, the downlink message cannot be sent normally.

Step 1502: After receiving the fault alarm message, the STA uses the second frequency band to send a request to exit the dual-mode transmission mode to the AP;

Step 1503: After receiving the request to exit the dual-mode transmission mode, the AP disconnects the association with the first frequency band of the STA.

In another embodiment, on the basis of the previous embodiment, after the STA and the AP disconnect the association of the first frequency band, they can initiate the re-association of the first frequency band, and when the re-association of the first frequency band is successful Then, renegotiate to enter the dual-mode transmission mode.

In this embodiment, it is assumed that the AP and the STA are in a normal working state in the dual-mode transmission mode, and the first frequency band is used for 2.4G to transmit uplink data, and the second frequency band is used for 5.8G to transmit downlink data. The negotiated bandwidth of 2.4G is 130Mbps, and the negotiated bandwidth of 5.8G is 867Mbps. Of course, you can also use the first frequency band to transmit downlink data for 2.4G, and use the second frequency band to transmit uplink data for 5.8G, without any specific restrictions.

As shown in Figure 16, the specific process includes:

Step 1601: When the AP uses the second frequency band for downlink transmission and detects a downlink transmission failure, it uses the first frequency band to send a failure warning message to the STA;

For example, in this embodiment, when the AP's 5.8G module fails, the downlink message cannot be sent normally.

Step 1602: After receiving the fault alarm message, the STA uses the first frequency band to send a request to exit the dual-mode transmission mode to the AP;

Step 1603: After receiving the request to exit the dual-mode transmission mode, the AP disconnects the association with the second frequency band of the STA.

In another embodiment, a communication method for a wireless local area network WLAN in a scenario where multiple STAs are associated with an AP is provided. As shown in Figure 17, the wireless local area network WLAN includes one AP and two STAs1 and 2.

Among them, STA1 and STA2 are normally associated with the AP using the 5.8GHZ frequency band, and are in the normal WLAN transmission mode, that is, the single-mode transmission mode. Both STA1 and STA2 support the first frequency band, the 2.4G frequency band, and the second frequency band, the 5.8G frequency band.

Normally, most APs and terminal devices on the market currently support dual-mode frequency bands (2.4GHZ and 5GHZ). Therefore, in this embodiment, the normal association of multiple STAs using the 5.8GHZ frequency band is taken as an example. The specific normal association and work flow are outside the scope of the present invention and will not be described here.

As shown in Figure 18, STA1 and STA2 negotiate with the AP to enter the dual-mode transmission mode, including:

Step 1801: STA1 and STA2 obtain AP capability information;

In this embodiment, the AP capability information can be obtained in the following two ways:

Method 1, STA1 and STA2 can actively initiate a request within a negotiation period to obtain AP capability information;

For example, you can use the message exchange in the 5.8GHZ frequency band to obtain AP capability information, including but not limited to the following:

Whether the AP supports the 5.8GHZ frequency band;

The specific channel supported by the AP;

Bandwidth range supported by the AP;

Supported wireless area codes;

The AP currently has associated equipment status, etc.

Method 2: AP actively sends its own capability information to STA1 and STA2;

For example, messages in the 5.8GHZ frequency band can be used to actively send AP capability information, including but not limited to the following:

Whether the AP supports the 5.8GHZ frequency band;

The specific channel supported by the AP;

Bandwidth range supported by the AP;

Supported wireless area codes;

The AP currently has associated equipment status, etc.

Step 1802: After obtaining the capability information of the AP, STA1 and STA2 each determine whether the capabilities of both parties match. When they match, they perform normal WLAN association with the AP in the first frequency band respectively, and negotiate to determine the frequency band and bandwidth value of each traffic direction. , And clock synchronization.

It should be noted here that only after the three parties of STA1, STA2, and AP confirm that the negotiation is successful, the system will proceed to the next step; otherwise, it should exit the negotiation process and enter the normal WLAN transmission mode state. When the three parties negotiate successfully, AP, STA1 and STA2 enter dual-mode transmission mode at the same time. For example, in this embodiment, as shown in Figure 19, the negotiated dual-mode transmission mode parameters are: use 2.4GHZ to transmit downlink packets, and 5.8GHZ to transmit Uplink message.

In this embodiment, on the basis of the previous embodiment, as shown in FIG. 20, STA1, STA2, and AP work normally in a dual-mode transmission mode. At this time, the third STA3 starts to request association from the AP. At this time, as shown in Figure 21, the method further includes steps 1801-1802:

Step 1803: STA3 sends an association request to AP;

For example, STA3 may send an association request for the first frequency band 2.4G or the second frequency band 5.8G to the AP.

Step 1804: The AP sends the locally stored dual-mode transmission mode parameters to STA3;

In this embodiment, the dual-mode transmission mode parameter is that 2.4 GHz is used to transmit downlink packets, and 5.8 GHz is used to transmit uplink packets.

Specifically, after receiving the request from STA3, the AP sends the parameter results negotiated with STA1 and STA2 stored in the local database to STA3.

Step 1805: After receiving the dual-mode transmission mode parameter, STA3 judges whether it can support it;

When it is supported, perform steps 1806-1807. When it is not supported, perform steps 1808-1809:

Step 1806, STA3 replies a message of successful negotiation to the AP, and enters the dual-mode transmission mode;

At this time, STA1, STA2, STA3 and AP complete the four-party negotiation and enter the working state of dual-mode transmission mode at the same time.

Step 1807, the AP sends clock synchronization messages to the three STAs 1, 2, and 3 cycles to synchronize the system clock, and the dual-mode transmission mode starts to work normally;

After the AP successfully negotiates with the three STAs, the AP periodically sends clock synchronization messages to the three STAs at the same time, so that the four devices complete the clock synchronization. The specific process is similar to FIG. 4 and will not be repeated.

In this way, the three STAs 1, 2, 3 and AP all enter the dual-mode transmission mode, as shown in Figure 22.

Step 1808, STA3 replies a negotiation failure message to the AP, requesting the AP to exit the dual-mode transmission mode state;

Step 1809: After the AP receives the negotiation failure message, STA1, STA2, and AP all exit the dual-mode transmission mode and return to the normal single-mode half-duplex transmission mode state.

Specifically, after the AP receives the negotiation failure message, it exits the dual-mode transmission mode and sends a notification to exit the dual-mode transmission mode to STA1 and STA2. After receiving the notification, the AP exits the dual-mode transmission mode and returns to the normal mode. The single-mode half-duplex transmission mode status.

The embodiment of the present invention also provides a wireless local area network WLAN communication system, as shown in FIG. 23, including:

The access point AP and wireless terminal STA associated with a normal WLAN; the AP and STA support the first frequency band and the second frequency band at the same time;

The AP and STA are set to negotiate to enter the dual-mode transmission mode;

For the specific implementation of the AP and STA negotiated to enter the dual-mode transmission mode, refer to the content of each of the above embodiments, which will not be repeated here.

The embodiment of the present invention also provides an access point AP, which is set to implement various operations performed by the AP in the above embodiments, and details are not described herein again.

Specifically, as shown in Figure 24, the AP includes:

The negotiation unit is set to negotiate with the wireless terminal STA associated with the normal WLAN to enter the dual-mode transmission mode;

Wherein, the negotiation unit includes:

The acquiring unit is configured to acquire the first capability information of the STA after the AP and the STA perform a normal WLAN association in the first frequency band; the first capability information includes whether the STA supports the second frequency band, and the STA supports The specific channel, bandwidth range, and wireless area code of the STA, and the current association status of the STA;

The judging and associating unit is configured to judge whether the capabilities of both parties match according to the first capability information, and when they match, perform normal WLAN association with the STA in the second frequency band;

The negotiation subunit is set to negotiate and determine the frequency band and bandwidth value of each traffic direction;

Clock synchronization unit, set to perform clock synchronization;

Or, include:

The acquiring unit is configured to acquire the third capability information of the STA after the AP and the STA perform normal WLAN association in the second frequency band; the third capability information includes whether the STA supports the first frequency band, and the STA supports The specific channel, bandwidth range, and wireless area code of the STA, and the current association status of the STA;

The judging and associating unit is configured to judge whether the capabilities of both parties match according to the third capability information, and when they match, perform normal WLAN association with the STA in the first frequency band;

Always synchronize the unit, set to synchronize the clock.

Among them, the AP includes:

The transmission unit is configured to use the second frequency band for downlink transmission when the dual-mode transmission mode is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission;

Alternatively, when the dual-mode transmission mode is to use the second frequency band for uplink transmission and the first frequency band for downlink transmission, use the first frequency band for downlink transmission.

Among them, the AP includes:

The anomaly detection and recovery unit is set to exit the dual-mode transmission mode or switch the frequency band of the traffic direction when the first frequency band and/or the second frequency band fail.

Wherein, the abnormality detection and recovery unit is specifically configured to receive a traffic direction adjustment request message sent by the STA to the AP using the second frequency band when the STA uses the first frequency band for uplink transmission and detects an uplink transmission failure; Detect whether the data traffic corresponding to the second frequency band exceeds the alarm threshold, and when it does not exceed, use the second frequency band to reply to the STA with a response message agreeing to adjust the direction; and switch to use the first frequency band for downlink transmission;

Or, it is specifically set to receive a traffic direction adjustment request message sent by the STA to the AP using the first frequency band when the STA uses the second frequency band for uplink transmission and detects an uplink transmission failure; and detect the data flow corresponding to the first frequency band Whether it exceeds the alarm threshold, and when it does not, use the first frequency band to reply to the STA a response message agreeing to adjust the direction; and switch to use the second frequency band for downlink transmission;

Or, it is specifically set that when the AP uses the first frequency band for downlink transmission and detects a downlink transmission failure, it uses the second frequency band to send a traffic direction adjustment request message to the STA; and it is received that the STA uses the second frequency band to send a request message to the STA. The AP replied with a response message agreeing to adjust the direction; then switched to use the second frequency band for downlink transmission;

Or, it is specifically set that when the AP uses the second frequency band for downlink transmission and detects a downlink transmission failure, it uses the first frequency band to send a traffic direction adjustment request message to the STA; and it is received that the STA uses the first frequency band to send a request message to the STA. The AP responds with a response message agreeing to adjust the direction; after that, it switches to using the first frequency band for downlink transmission.

Wherein, the abnormality detection and recovery unit is specifically configured to receive a failure alarm message sent by the STA to the AP using the second frequency band when the STA uses the first frequency band for uplink transmission and detects an uplink transmission failure; After the failure warning message, use the second frequency band to send a request to exit the dual-mode transmission mode to the STA; and disconnect the association with the first frequency band of the STA;

Or, the specific setting is that when the STA uses the second frequency band for uplink transmission and detects an uplink transmission failure, it receives a failure alarm message sent by the STA to the AP using the first frequency band; after receiving the failure alarm message, use The first frequency band sends a request to exit the dual-mode transmission mode to the STA; and disconnects the association with the second frequency band of the STA;

Or, it is specifically set to use the second frequency band to send a failure alarm message to the STA when the AP uses the first frequency band for downlink transmission and detects a downlink transmission failure; and upon receiving the STA using the second frequency band to send a failure warning message to the AP When sending a request to exit the dual-mode transmission mode, disconnect the association with the first frequency band of the STA;

Or, it is specifically set to use the first frequency band to send a failure warning message to the STA when the AP uses the second frequency band for downlink transmission and detects a downlink transmission failure; and when the STA uses the first frequency band to send a failure warning message to the AP When the sent request to exit the dual-mode transmission mode, the association with the second frequency band of the STA is disconnected.

Wherein, the negotiation unit is further configured to initiate re-association of the first frequency band after the AP and STA are disconnected from the first frequency band, and when the re-association of the first frequency band is successful, renegotiate to enter dual mode Transmission mode

The embodiment of the present invention also provides a wireless terminal STA, which is configured to implement various operations performed by the STA in the above embodiments, and details are not described herein again.

Specifically, as shown in Figure 25, the STA includes:

The negotiation unit is set to negotiate with the access point AP associated with the normal WLAN to enter the dual-mode transmission mode; wherein the AP and STA support the first frequency band and the second frequency band at the same time; the dual-mode transmission mode is to use the first frequency band For uplink transmission, use the second frequency band for downlink transmission; or use the second frequency band for uplink transmission and use the first frequency band for downlink transmission.

Wherein, the negotiation unit includes: an acquiring unit configured to acquire the second capability information of the AP after the AP and the STA perform normal WLAN association in the first frequency band; the second capability information includes whether the AP Supporting the second frequency band, the specific channel, bandwidth range, and wireless area code supported by the AP, and the current association status of the AP;

The judging and associating unit is configured to judge whether the capabilities of both parties match according to the second capability information, and when they match, perform normal WLAN association with the AP in the second frequency band;

Clock synchronization unit, set to perform clock synchronization;

Or, include:

The acquiring unit is configured to acquire the fourth capability information of the AP after the AP and the STA perform a normal WLAN association in the second frequency band; the fourth capability information includes whether the AP supports the first frequency band, and the AP supports The specific channel, bandwidth range, and wireless area code of the STA, and the current association status of the STA;

The judging and associating unit is configured to judge whether the capabilities of both parties match according to the fourth capability information, and when they match, perform normal WLAN association with the AP in the first frequency band;

The clock synchronization unit is set to perform clock synchronization.

Among them, the STA also includes:

The transmission unit is configured to use the first frequency band for uplink transmission when the dual-mode transmission mode is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission;

Or, when the dual-mode transmission mode is to use the second frequency band for uplink transmission and the first frequency band for downlink transmission, use the second frequency band for uplink transmission.

Among them, the STA also includes:

Wherein, the abnormality detection and recovery unit is specifically configured to use the second frequency band to send a traffic direction adjustment request message to the AP when the STA uses the first frequency band for uplink transmission and detects an uplink transmission failure; When the frequency band receives the response message that the AP replied to agree to the direction adjustment, it switches to use the second frequency band for uplink transmission;

Or, the specific setting is that when the STA uses the second frequency band for uplink transmission and detects an uplink transmission failure, the first frequency band is used to send a traffic direction adjustment request message to the AP; the first frequency band is used to receive the consent reply from the AP When the response message is tuned, switch to use the first frequency band for uplink transmission;

Or, it is specifically set to receive a traffic direction adjustment request message sent by the AP to the STA using the second frequency band when the AP uses the first frequency band for downlink transmission and detects a downlink transmission failure; and detect the data flow corresponding to the second frequency band Whether it exceeds the alarm threshold, when it does not, use the second frequency band to reply to the AP with a response message agreeing to adjust the direction; then switch to using the first frequency band for downlink transmission;

Or, it is specifically set to receive a traffic direction adjustment request message sent by the AP to the STA using the first frequency band when the AP uses the second frequency band for downlink transmission and detects a downlink transmission failure; and detect the data flow corresponding to the first frequency band Whether it exceeds the alarm threshold, when it does not, use the first frequency band to reply to the AP a response message agreeing to adjust the direction; then switch to use the second frequency band for uplink transmission.

Wherein, the abnormality detection and recovery unit is specifically configured to use the second frequency band to send a failure warning message to the AP when the STA uses the first frequency band for uplink transmission and detects an uplink transmission failure; and to use the second frequency band to receive When the AP sends a request to exit the dual-mode transmission mode, disconnect the association with the first frequency band of the AP;

Or, the specific setting is that when the STA uses the second frequency band for uplink transmission and detects an uplink transmission failure, it uses the first frequency band to send a failure warning message to the AP; and uses the first frequency band to receive the exit sent by the AP to the STA When the dual-mode transmission mode is requested, disconnect the association with the second frequency band of the AP;

Or, it is specifically set that when the AP uses the first frequency band for downlink transmission and detects a downlink transmission failure, it uses the second frequency band to receive the failure alarm message sent by the AP to the STA; after receiving the failure alarm message, use The second frequency band sends a request to exit the dual-mode transmission mode to the AP, and then disconnects the association with the first frequency band of the AP;

Or, it is specifically set to use the first frequency band to receive the fault alarm message sent by the AP to the STA when the AP uses the second frequency band for downlink transmission and detects a downlink transmission failure; after receiving the fault alarm message, use The first frequency band sends a request to exit the dual-mode transmission mode to the AP, and the association with the second frequency band of the AP is disconnected.

Wherein, when there are multiple STAs, the dual-mode transmission modes negotiated by the multiple STAs and the AP are the same.

The embodiment of the present invention also provides an access point AP, including a memory, a processor, and a computer program stored on the memory and running on the processor. When the computer program is executed by the processor, The various operations performed by the AP in the above embodiments are implemented, which will not be repeated here.

The embodiment of the present invention also provides a wireless terminal STA including a memory, a processor, and a computer program stored on the memory and capable of running on the processor. When the computer program is executed by the processor, the above Various operations performed by the STA in each embodiment will not be repeated here.

The embodiment of the present invention also provides a computer-readable storage medium, the computer-readable storage medium stores an information processing program, and when the information processing program is executed by a processor, it realizes the execution of the AP or STA in each of the above embodiments. Various operations are not repeated here.

The technical solution provided by the embodiment of the present invention has the following advantages:

1. Make full use of the idle resources of the device: For dual-mode devices, make full use of their idle frequency band resources for data transmission, which significantly improves the transmission efficiency of the WLAN access system;

2. There is no need to increase the hardware cost of the device: all functions in the embodiments of the present invention can be completed based on the realization of software programs, and there will be no speed-up means such as increasing the number of antennas, which greatly increases the hardware cost and volume of the device;

3. Without changing the basis of the WLAN half-duplex protocol, WLAN two-way simultaneous transmission is realized by using idle frequency bands, which is relatively simple compared with the existing technical solutions that implement WLAN full-duplex mode;

4. The dual-mode frequency band is used to transmit uplink and downlink messages separately to avoid co-frequency interference of messages.

A person of ordinary skill in the art can understand that all or some of the steps, functional modules/units in the system, and apparatus in the methods disclosed above can be implemented as software, firmware, hardware, and appropriate combinations thereof. In the hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may consist of several physical components. The components are executed cooperatively. Some or all of the components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, and the computer-readable medium may include a computer storage medium (or a non-transitory medium) and a communication medium (or a transitory medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile data implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Sexual, removable and non-removable media. Computer storage media include but are not limited to RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or Any other medium used to store desired information and that can be accessed by a computer. In addition, as is well known to those of ordinary skill in the art, communication media usually contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as carrier waves or other transmission mechanisms, and may include any information delivery media. .

Industrial applicability

The embodiment of the present invention provides a wireless local area network WLAN communication method, through the normal WLAN associated access point AP and wireless terminal STA negotiate to enter the dual-mode transmission mode; wherein, the AP and STA support both the first frequency band and the second frequency band. Frequency band; the dual-mode transmission mode is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission; or use the second frequency band for uplink transmission and the first frequency band for downlink transmission, thereby not significantly increasing equipment hardware costs On the basis of WLAN, the access transmission rate of WLAN is improved.

Claims

A communication method for wireless local area network WLAN includes:

The access point AP and the wireless terminal STA associated with the normal WLAN negotiate to enter the dual-mode transmission mode;

Wherein, the AP and STA support the first frequency band and the second frequency band at the same time;

The dual-mode transmission mode is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission; or use the second frequency band for uplink transmission and the first frequency band for downlink transmission.
The method according to claim 1, wherein the negotiation between the AP and the STA to enter a dual-mode transmission mode includes:

After the AP and the STA perform a normal WLAN association in the first frequency band, the AP obtains the first capability information of the STA; the first capability information includes whether the STA supports the second frequency band, and the specific information supported by the STA Channel, bandwidth range, and wireless area code, the STA has currently associated status;

The AP judges whether the capabilities of the two parties match according to the first capability information, and when they match, it performs normal WLAN association with the STA in the second frequency band, negotiates to determine the frequency band and bandwidth value of each traffic direction, and performs clock synchronization ；

Alternatively, after the AP and the STA perform a normal WLAN association in the first frequency band, the STA obtains the second capability information of the AP; the second capability information includes whether the AP supports the second frequency band, and the AP supports The specific channel, bandwidth range, and wireless area code of the AP, and the current status of the AP;

The STA judges whether the capabilities of the two parties match according to the second capability information, and when they match, they perform normal WLAN association with the AP in the second frequency band, negotiate to determine the frequency band and bandwidth value of each traffic direction, and perform clock synchronization ；

Alternatively, after the AP and the STA perform a normal WLAN association in the second frequency band, the AP obtains the third capability information of the STA; the third capability information includes whether the STA supports the first frequency band, and the STA supports The specific channel, bandwidth range, and wireless area code of the STA, and the current association status of the STA;

The AP judges whether the capabilities of both parties match according to the third capability information. When they match, they perform normal WLAN association with the STA in the first frequency band, and negotiate to determine the frequency band and bandwidth value of each traffic direction, and perform clock synchronization ；

Or, after the AP and the STA perform a normal WLAN association in the second frequency band, the STA obtains fourth capability information of the AP; the fourth capability information includes whether the AP supports the first frequency band, and the AP supports The specific channel, bandwidth range, and wireless area code of the STA, and the current association status of the STA;

The STA judges whether the capabilities of both parties match according to the fourth capability information. When they match, they perform normal WLAN association with the AP in the first frequency band, negotiate to determine the frequency band and bandwidth value of each traffic direction, and perform clock synchronization .
The method according to claim 1, wherein after the AP and the STA negotiate to enter the dual-mode transmission mode, the method further comprises:

When the dual-mode transmission mode is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission, the STA uses the first frequency band for uplink transmission, and the AP uses the second frequency band for downlink transmission;

Alternatively, when the dual-mode transmission mode is to use the second frequency band for uplink transmission and the first frequency band for downlink transmission, the STA uses the second frequency band for uplink transmission, and the AP uses the first frequency band for downlink transmission.
The method according to claim 3, wherein the method further comprises:

When the first frequency band and/or the second frequency band fail, exit the dual-mode transmission mode or switch the frequency band of the traffic direction.
The method according to claim 4, wherein said performing frequency band switching in the direction of traffic comprises:

When the STA uses the first frequency band for uplink transmission and detects an uplink transmission failure, use the second frequency band to send a traffic direction adjustment request message to the AP;

The AP detects whether the data traffic corresponding to the second frequency band exceeds the alarm threshold, and when it does not exceed the alarm threshold, uses the second frequency band to reply to the STA a response message agreeing to adjust the direction;

The STA switches to use the second frequency band for uplink transmission, and the AP switches to use the first frequency band for downlink transmission;

Or, when the STA uses the second frequency band for uplink transmission and detects an uplink transmission failure, use the first frequency band to send a traffic direction adjustment request message to the AP;

The AP detects whether the data traffic corresponding to the first frequency band exceeds the alarm threshold, and when it does not exceed the alarm threshold, uses the first frequency band to reply to the STA a response message agreeing to adjust the direction;

The STA switches to use the first frequency band for uplink transmission, and the AP switches to use the second frequency band for downlink transmission;

Or, when the AP uses the first frequency band for downlink transmission and detects a downlink transmission failure, it uses the second frequency band to send a traffic direction adjustment request message to the STA;

The STA detects whether the data traffic corresponding to the second frequency band exceeds the alarm threshold, and when it does not exceed the alarm threshold, uses the second frequency band to reply to the AP with a response message agreeing to adjust the direction;

The AP switches to use the second frequency band for downlink transmission, and the STA switches to use the first frequency band for uplink transmission;

Or, when the AP uses the second frequency band for downlink transmission and detects a downlink transmission failure, it uses the first frequency band to send a traffic direction adjustment request message to the STA;

The STA detects whether the data traffic corresponding to the first frequency band exceeds an alarm threshold, and when it does not exceed the alarm threshold, uses the first frequency band to reply to the AP with a response message agreeing to adjust the direction;

The AP switches to use the first frequency band for downlink transmission, and the STA switches to use the second frequency band for uplink transmission.
The method according to claim 4, wherein the exiting the dual-mode transmission mode comprises:

When the STA uses the first frequency band for uplink transmission and detects an uplink transmission failure, use the second frequency band to send a failure warning message to the AP;

After receiving the failure warning message, the AP uses the second frequency band to send a request to exit the dual-mode transmission mode to the STA;

After the STA receives the request to exit the dual-mode transmission mode, it disconnects the association with the first frequency band of the AP;

Or, when the STA uses the second frequency band for uplink transmission and detects an uplink transmission failure, use the first frequency band to send a failure warning message to the AP;

After receiving the fault alarm message, the AP uses the first frequency band to send a request to exit the dual-mode transmission mode to the STA;

After receiving the request to exit the dual-mode transmission mode, the STA disconnects the association with the second frequency band of the AP;

Or, when the AP uses the first frequency band for downlink transmission and detects a downlink transmission failure, it uses the second frequency band to send a failure warning message to the STA;

After receiving the failure warning message, the STA uses the second frequency band to send a request to exit the dual-mode transmission mode to the AP;

After receiving the request to exit the dual-mode transmission mode, the AP disconnects the association with the first frequency band of the STA;

Or, when the AP uses the second frequency band for downlink transmission and detects a downlink transmission failure, it uses the first frequency band to send a failure warning message to the STA;

After receiving the fault alarm message, the STA uses the first frequency band to send a request to exit the dual-mode transmission mode to the AP;

After receiving the request to exit the dual-mode transmission mode, the AP disconnects the association with the second frequency band of the STA.
The method according to claim 6, wherein after the exit of the dual-mode transmission mode, the method further comprises:

After the AP and the STA disconnect the association of the first frequency band, initiate a re-association of the first frequency band, and when the re-association of the first frequency band is successful, renegotiate to enter the dual-mode transmission mode;

Alternatively, after the AP and the STA are disconnected from the second frequency band, re-association of the second frequency band is initiated, and after the re-association of the second frequency band is successful, renegotiate to enter the dual-mode transmission mode.
The method of claim 1, wherein:

When there are multiple STAs, the dual-mode transmission modes negotiated by the AP and the multiple STAs are the same.
The method of claim 1, wherein:

The first frequency band is a 2.4G frequency band, and the second frequency band is a 5.8G frequency band;

Alternatively, the first frequency band is a 5.8G frequency band, and the second frequency band is a 2.4G frequency band.
A wireless local area network WLAN communication system, which includes:

The access point AP and wireless terminal STA associated with a normal WLAN; the AP and STA support the first frequency band and the second frequency band at the same time;

The AP and STA are set to negotiate to enter the dual-mode transmission mode;

The dual-mode transmission mode is to use the first frequency band for uplink transmission and the second frequency band for downlink transmission; or use the second frequency band for uplink transmission and the first frequency band for downlink transmission.