CN106471785B - A virtual carrier sensing method and device - Google Patents

Abstract

A virtual carrier sensing method and device, wherein the method includes: receiving a transmission frame, the transmission frame includes a service field and a duration field, wherein the service field includes a check field, and the check field carries a first check value , the first check value is obtained after the second check value is carried in the check field and transmitted through the wireless channel, and the second check value is calculated according to a predetermined algorithm according to the field set when the wireless device sending the transmission frame generates the transmission frame obtained; wherein, the field set is a part of the fields included in the transmission frame, and the field set includes a duration field; the duration field includes a duration (S101); according to the first check value, it is determined whether the duration is a valid duration (S102); when it is determined that the duration is a valid duration, the network allocation vector timer of the local end is updated with the duration (S103). The method can improve the reliability of virtual carrier sense.

Description

A virtual carrier sensing method and device

technical field

The present invention relates to the field of communication technologies, and in particular, to a virtual carrier sensing method and device.

Background technique

Virtual Carrier Sense (Virtual Carrier Sense, VCS) is an important transmission protection mechanism in the Institute of Electrical and Electronics Engineers (Institute of Electrical and Electronics Engineers, IEEE) 802.11 standard. In the VCS mechanism, data is transmitted in the form of a transmission frame. The transmission frame includes a physical header and data, and the data includes a service (SERVICE) field and a physical layer convergence procedure service data unit (Physical Layer Convergence Procedure Service Data Unit, PSDU). PSDU is media access control (Media Access Control, MAC) layer data, including MAC frame header, frame body and frame check sequence (Frame Check Sequence, FCS). The MAC frame header includes a duration field for indicating the expected remaining time for the transmission of data including the transmission frame between the source wireless device and the destination wireless device.

At present, a common virtual carrier sensing method is: when a transmission frame is transmitted from a source wireless device to a destination wireless device through a wireless channel, other wireless devices using the same wireless channel with the two wireless devices may receive the transmission frame including Then use FCS to determine whether the transmission frame is a valid frame, and when the transmission frame is a valid frame, set a Network Allocation Vector (NAV) timer according to the duration field included in the transmission frame. Before the NAV timer is decremented to zero, these wireless devices cannot send data through the wireless channel even if they sense that the wireless channel is idle, so as to avoid interference to wireless devices that are transmitting data on the wireless channel.

In the above method, when the transmission frame is an invalid frame, these devices cannot set the NAV timer according to the duration, and will send data on the wireless channel, so that multiple wireless devices simultaneously send data in the same wireless channel at the same time , which reduces the reliability of virtual carrier sense.

SUMMARY OF THE INVENTION

The embodiment of the present invention discloses a virtual carrier sensing method and device, which are used for improving the virtual carrier sensing reliability.

A first aspect of the embodiments of the present invention discloses a virtual carrier sensing method, including:

Receive a transmission frame, the transmission frame includes a service field and a duration field, wherein the service field includes a check field, and the check field carries a first check value, and the first check value is the first check value. The second check value is carried in the check field and obtained after wireless channel transmission, and the second check value is calculated according to a predetermined algorithm according to the field set when the wireless device sending the transmission frame generates the transmission frame obtained; wherein the field set is a part of the fields included in the transmission frame, the field set includes the duration field; the duration field includes the duration;

determining whether the duration is a valid duration according to the first check value;

When it is determined that the duration is a valid duration, the NAV timer of the local end is updated with the duration.

With reference to the first aspect of the embodiments of the present invention, in a first possible implementation manner of the first aspect of the embodiments of the present invention, the determining whether the duration is a valid duration according to the first check value includes: :

The third check value is obtained by calculating according to the field set according to the predetermined algorithm;

When the first check value matches the third check value, the duration is determined to be a valid duration.

With reference to the first aspect of the embodiment of the present invention or the first possible implementation manner of the first aspect of the embodiment of the present invention, in the second possible implementation manner of the first aspect of the embodiment of the present invention, the transmission frame further includes the receiving address field, the receiving address field includes the receiving address of the transmission frame, and the field set further includes the receiving address field;

When it is determined that the duration is a valid duration, using the duration to update the NAV timer of the local end includes:

When it is determined according to the first check value that the duration is a valid duration and the receiving address is a valid receiving address, if the receiving address does not match the address of the local end, and the duration is greater than the NAV of the local end The time of the timer, which is used to update the NAV timer of the local end.

With reference to the second possible implementation manner of the first aspect of the embodiment of the present invention, in the third possible implementation manner of the first aspect of the embodiment of the present invention, the transmission frame further includes a physical header, and the physical header includes an indication information, where the indication information is used to indicate that the transmission frame includes the check field.

A second aspect of the embodiments of the present invention discloses a virtual carrier sensing method, including:

Generate a transmission frame, the transmission frame includes a service field and a duration field, wherein the service field includes a check field, and the check field carries a second check value, and the second check value is based on the field The set is calculated according to a predetermined algorithm, the field set is a part of the fields included in the transmission frame, the field set includes the duration field, and the duration field includes the duration;

Send the transmission frame, so that the wireless device that receives the transmission frame determines whether the duration is a valid duration according to the first check value, and when determining that the duration is a valid duration, utilizes the The network allocation vector timer of the wireless device is updated with the duration, wherein the first check value is obtained after the second check value is carried in the check field and transmitted through a wireless channel.

With reference to the second aspect of the embodiment of the present invention, in a first possible implementation manner of the second aspect of the embodiment of the present invention, the transmission frame further includes a receiving address field, and the receiving address field includes a receiving address of the transmission frame , the field set further includes the receiving address field.

With reference to the first possible implementation manner of the second aspect of the embodiment of the present invention, in the second possible implementation manner of the second aspect of the embodiment of the present invention, the transmission frame further includes a physical header, and the physical header includes an indication information, where the indication information is used to indicate that the transmission frame includes the check field.

A third aspect of the embodiments of the present invention discloses a wireless device, including:

a receiving unit, configured to receive a transmission frame, where the transmission frame includes a service field and a duration field, wherein the service field includes a check field, and the check field carries a first check value, and the first check value is The check value is obtained after the second check value is carried in the check field and transmitted through the wireless channel, and the second check value is obtained according to the field when the wireless device sending the transmission frame generates the transmission frame The set is calculated according to a predetermined algorithm; wherein, the field set is a part of the fields included in the transmission frame, and the field set includes the duration field; the duration field includes the duration;

a judging unit, configured to determine whether the duration is a valid duration according to the first check value included in the transmission frame received by the receiving unit;

an update unit, configured to update the NAV timer of the wireless device by using the duration when the determination unit determines that the duration is a valid duration.

With reference to the third aspect of the embodiment of the present invention, in the first possible implementation manner of the third aspect of the embodiment of the present invention, the judging unit is specifically configured to:

The third check value is obtained by calculating according to the field set according to the predetermined algorithm;

When the first check value matches the third check value, the duration is determined to be a valid duration.

With reference to the third aspect of the embodiment of the present invention or the first possible implementation manner of the third aspect of the embodiment of the present invention, in the second possible implementation manner of the third aspect of the embodiment of the present invention, the transmission frame further includes the receiving address field, the receiving address field includes the receiving address of the transmission frame, and the field set further includes the receiving address field;

The updating unit is specifically configured to, when it is determined according to the first check value that the duration is a valid duration and the receiving address is a valid receiving address, if the receiving address and the address of the wireless device are different, match, and the duration is greater than the time of the NAV timer of the wireless device, the NAV timer of the wireless device is updated with the duration.

With reference to the second possible implementation manner of the third aspect of the embodiment of the present invention, in the third possible implementation manner of the third aspect of the embodiment of the present invention, the transmission frame further includes a physical header, and the physical header includes an indication information, where the indication information is used to indicate that the transmission frame includes the check field.

A fourth aspect of the embodiments of the present invention discloses a wireless device, including a processor, a memory, and an input device, wherein:

The input device is configured to receive and send a transmission frame to the processor, where the transmission frame includes a service field and a duration field, wherein the service field includes a check field, and the check field carries the first A check value, the first check value is obtained after the second check value is carried in the check field and transmitted through the wireless channel, and the second check value is the wireless channel sending the transmission frame. When the device generates the transmission frame, it is calculated according to a predetermined algorithm according to a field set; wherein, the field set is a part of the fields included in the transmission frame, and the field set includes the duration field; the duration field The time field includes the duration;

A set of program codes are stored in the memory, and the processor is configured to call the program codes stored in the memory to perform the following operations:

determining whether the duration is a valid duration according to the first check value;

When the duration is determined to be a valid duration, the NAV timer of the wireless device is updated with the duration.

With reference to the fourth aspect of the embodiment of the present invention, in a first possible implementation manner of the fourth aspect of the embodiment of the present invention, the processor is configured to determine whether the duration is a valid duration according to the first check value The time is as follows:

The processor is configured to calculate and obtain a third check value according to the field set according to the predetermined algorithm;

When the first check value matches the third check value, the duration is determined to be a valid duration.

With reference to the fourth aspect of the embodiment of the present invention or the first possible implementation manner of the fourth aspect of the embodiment of the present invention, in the second possible implementation manner of the fourth aspect of the embodiment of the present invention, the transmission frame further includes the receiving address field, the receiving address field includes the receiving address of the transmission frame, and the field set further includes the receiving address field;

When the processor determines that the duration is a valid duration, the manner in which the NAV timer of the local end is updated by using the duration is specifically:

The processor is configured to, when determining according to the first check value that the duration is a valid duration and the receiving address is a valid receiving address, if the receiving address does not match the address of the wireless device, and If the duration is greater than the time of the NAV timer of the wireless device, the NAV timer of the wireless device is updated with the duration.

With reference to the second possible implementation manner of the fourth aspect of the embodiment of the present invention, in the third possible implementation manner of the fourth aspect of the embodiment of the present invention, the transmission frame further includes a physical header, and the physical header includes an indication information, where the indication information is used to indicate that the transmission frame includes the check field.

A fifth aspect of the embodiments of the present invention discloses a wireless device, including:

A generating unit, configured to generate a transmission frame, where the transmission frame includes a service field and a duration field, wherein the service field includes a check field, and the check field carries a second check value, and the second check value is The check value is calculated according to a predetermined algorithm according to a field set, the field set is a part of the fields included in the transmission frame, the field set includes the duration field, and the duration field includes the duration;

A sending unit, configured to send the transmission frame generated by the generating unit, so that the target wireless device that receives the transmission frame determines whether the duration is a valid duration according to the first check value, and when determining the When the duration is a valid duration, use the duration to update the network allocation vector timer of the target wireless device, wherein the first check value is the second check value carried in the check field obtained through wireless channel transmission.

With reference to the fifth aspect of the embodiment of the present invention, in a first possible implementation manner of the fifth aspect of the embodiment of the present invention, the transmission frame further includes a receiving address field, and the receiving address field includes a receiving address of the transmission frame , the field set further includes the receiving address field.

With reference to the first possible implementation manner of the fifth aspect of the embodiment of the present invention, in the second possible implementation manner of the fifth aspect of the embodiment of the present invention, the transmission frame further includes a physical header, and the physical header includes an indication information, where the indication information is used to indicate that the transmission frame includes the check field.

A sixth aspect of the embodiments of the present invention discloses a wireless device, including a processor, a memory, and an output device, wherein:

A set of program codes are stored in the memory, and the processor is configured to call the program codes stored in the memory to perform the following operations:

Generate a transmission frame, the transmission frame includes a service field and a duration field, wherein the service field includes a check field, and the check field carries a second check value, and the second check value is based on the field The set is calculated according to a predetermined algorithm, the field set is a part of the fields included in the transmission frame, the field set includes the duration field, and the duration field includes the duration;

The output device is configured to send the transmission frame, so that the target wireless device receiving the transmission frame determines whether the duration is a valid duration according to the first check value, and when determining the duration When it is a valid duration, use the duration to update the network allocation vector timer of the target wireless device, wherein the first check value is the second check value carried in the check field after the obtained after wireless channel transmission.

With reference to the sixth aspect of the embodiment of the present invention, in a first possible implementation manner of the sixth aspect of the embodiment of the present invention, the transmission frame further includes a receiving address field, and the receiving address field includes a receiving address of the transmission frame , the field set further includes the receiving address field.

With reference to the first possible implementation manner of the sixth aspect of the embodiment of the present invention, in the second possible implementation manner of the sixth aspect of the embodiment of the present invention, the transmission frame further includes a physical header, and the physical header includes an indication information, where the indication information is used to indicate that the transmission frame includes the check field.

In the existing method, the wireless device uses the duration to update the NAV timer of the local end only when the received transmission frame is a valid frame; when the received transmission frame is an invalid frame, the wireless device cannot set the NAV timing according to the duration. If the device is installed, it will send data on the wireless channel, so that multiple wireless devices simultaneously send data in the same wireless channel at the same time, which reduces the reliability of virtual carrier sense. In the virtual carrier sensing method provided by the embodiment of the present invention, a check field is included in the service field of the transmission frame, and the duration included in the received transmission frame is determined according to the first check value carried in the check field Whether it is a valid duration or not, no matter whether the received transmission frame is a valid frame or not, that is, it is not necessary to use FCS to determine whether the transmission frame is a valid frame or not, but only the duration included in the transmission frame needs to be checked. When it is determined that the duration included in the transmission frame is a valid duration, the NAV timer of the local end can be updated by using the duration, so that the local end does not send data before the time of the NAV timer is decremented to zero, so as to avoid the same wireless radio at the same time. In the channel, multiple wireless devices transmit data at the same time, so that the reliability of virtual carrier sense can be improved.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a flowchart of a method for virtual carrier sensing disclosed in an embodiment of the present invention;

2 is a process of utilizing a scrambling code generator to carry a check value disclosed in an embodiment of the present invention;

3 is a flowchart of another virtual carrier sensing method disclosed in an embodiment of the present invention;

4 is a flowchart of a method for compressing a MAC frame header disclosed in an embodiment of the present invention;

5 is a flowchart of another MAC frame header compression method disclosed in an embodiment of the present invention;

6 is a structural diagram of a wireless device disclosed in an embodiment of the present invention;

7 is a structural diagram of another wireless device disclosed in an embodiment of the present invention;

8 is a structural diagram of another wireless device disclosed in an embodiment of the present invention;

9 is a structural diagram of another wireless device disclosed in an embodiment of the present invention;

10 is a structural diagram of another wireless device disclosed in an embodiment of the present invention;

11 is a structural diagram of another wireless device disclosed in an embodiment of the present invention;

12 is a structural diagram of another wireless device disclosed in an embodiment of the present invention;

FIG. 13 is a structural diagram of another wireless device disclosed in an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The embodiment of the present invention discloses a virtual carrier sensing method and device, which are used for improving the virtual carrier sensing reliability. Each of them will be described in detail below.

Due to the unreliability of the wireless channel, the transmission of the transmission frame may go wrong, resulting in the content of the transmission frame received by the receiving end being different from the content generated by the transmitting end. In the prior art, in order to enable the receiving end to know whether the received transmission frame is correct or not, the transmitting end adds additional check data to the transmission frame, that is, the content of the transmission frame is input into a predetermined check algorithm to obtain the sending check value, It is then carried in the frame check field of the transmission frame and sent. After receiving the transmission frame, the receiving end calculates the content of the transmission frame using the same check algorithm as the receiving end to obtain the receiving check value, and then compares it with the sending check value obtained from the received transmission frame. If the two match, it is considered that the content of the transmission frame is received correctly, that is, the transmission frame is a valid frame; if they do not match, it means that the content of the transmission frame is in error during the transmission process, or the transmission of the check value is wrong, that is, the transmission frame is invalid frame, at this time, the receiving end discards the transmission frame.

Errors caused by unreliable wireless channels can appear anywhere in the transmission frame. When the device receives an invalid transmission frame (that is, when the frame check value match result is mismatched), the duration field in the transmission frame may still be correct. At this time, the duration in the duration field can still be used to set It has its own NAV timer, but in the prior art, when an invalid transmission frame is received, the frame is discarded, and the information of the still valid duration in the invalid transmission frame is not used. Therefore, a mechanism is required so that the receiving end can judge whether the duration field in the transmission frame is erroneous even in the case of the overall transmission error of the received transmission frame.

On the other hand, from the perspective of implementation, since the frame check field is located at the end of the frame, when the device receives a transmission frame and determines that the frame does not need to be received by itself according to the receiving address field in the frame header, it will directly discard it. This frame, and will not continue to receive subsequent parts of the transmission frame, in order to save energy. In this case, the receiving device has no way to judge whether the duration field is received correctly or not. Using it to set the NAV timer may cause unpredictable problems if it is received incorrectly. Therefore, it is necessary to accurately determine whether the duration field is received correctly when the wireless device only receives the frame header.

To sum up, it is necessary to add a new check field in the frame header and the previous position in the transmission frame to check the duration field. The method enables the receiving wireless device to judge whether the duration field is received correctly when only part of the transmission frame is received, so that the NAV timer is set correctly and energy can be saved; at the same time, even when an invalid transmission frame is received In this case, the receiving wireless device can also independently determine whether the duration field is received correctly, so as to use it to set the NAV timer. Compared with the existing method, the method provided by the embodiment of the present invention enables the wireless device to obtain the effective duration in more situations, thereby making the virtual carrier sense mechanism more effective.

Please refer to FIG. 1. FIG. 1 is a flowchart of a virtual carrier sensing method disclosed in an embodiment of the present invention. Among them, the virtual carrier sensing method shown in FIG. 1 is suitable for wireless devices such as mobile phones and tablet computers. The virtual carrier sensing method shown in FIG. 1 is described from the perspective of the receiving side. As shown in FIG. 1 , the virtual carrier sensing method may include the following steps.

S101. Receive a transmission frame, where the transmission frame includes a service field and a duration field, wherein the service field includes a check field, the check field carries a first check value, and the first check value is a second check value carried The second check value is obtained after transmission through the wireless channel in the check field, and the second check value is calculated according to a predetermined algorithm according to the field set when the wireless device sending the transmission frame generates the transmission frame; wherein, the field set is one of the fields included in the transmission frame. part of the field, the field set includes the duration field; the duration field includes the duration.

In this embodiment, the received transmission frame includes a physical header and data, and the data includes a service field, a PSDU, a tail (Tail), and a pad (Pad). Among them, in some cases, the tail and padding parts do not exist in the data. PSDU is MAC layer data, PSDU includes MAC frame header, frame body and FCS, MAC frame header includes duration field, and duration field includes duration. The service field includes a check field and a Scrambler Initialization, wherein the check field carries a first check value, and the first check value is the second check value carried in the check field Obtained after transmission through the wireless channel, the second check value is calculated according to a predetermined algorithm according to the field set when the wireless device sending the transmission frame generates the transmission frame; wherein the field set is a part of the fields included in the transmission frame, and the field A set includes a duration field; a duration field includes a duration. The first check value and the second check value may or may not be equal; when the check field is transmitted incorrectly during the transmission process, the two are not equal; when the check field is transmitted correctly during the transmission process, Both are equal.

In this embodiment, the service field may carry the check value through the basic method or the extension method. The basic method is: the length of the service field is generally 16bits, of which 7bits is the initial value of the scrambling code generator and cannot carry information. Therefore, the remaining 9bits can be used to carry the check value. It has been proposed in the 802.11ac standard to use the 8bits in the service field. The method of carrying the check value, but the check value is the check value of the VTH-SIG-B field in the physical header. Therefore, a similar method (that is, using some or all of the remaining 9 bits) can be used to carry the field If the check value of the SIG field in the physical header needs to be carried, the field set will also include the SIG field in the physical header. The shorter the length of the check value, the easier it is to cause misjudgment. Therefore, the extended method further increases the length of the check value on the basis of the basic method. Specifically, the initial state value of the scrambling code generator of the source wireless device of the transmission frame is implicitly carried. Check value to increase the length of the check value.

In this embodiment, the initial value (Initialization) and the initial state value (InitialState) of the scrambling code generator are two different concepts. The former is the name of a subfield in the SERVICE field, with a length of 7 bits, usually a fixed value, such as the current 802.11 standard to take a sequence of 7 bits all 0s; the latter is the initial value of the 7-bit shift register in the scrambling code generator, the length It is 7bits, usually random but not all 0, used to generate scrambling code sequence. In actual transmission, the sender first generates a scrambling code sequence based on the initial state value of 7 bits, and then uses the first 7 bits in the scrambling code sequence and the 7 bits all-zero sequence of the initial value of the scrambling code generator to perform XOR operation respectively, and use the result as scrambling. The latter data is sent on the wireless channel; after the receiving end receives the scrambled data, it XORs it again with the 7-bit all-zero sequence of the initial value of the scrambling code generator, so as to obtain the first 7 bits of the scrambled code sequence at the transmitting end. According to the specific structure of the scrambling code generator, the receiving end can reversely derive the initial state value used by the transmitting end to generate the scrambling code sequence from the 7-bit scrambling code sequence, and then generate the same scrambling code sequence as the transmitting end, which is used for Receiver descrambling. The initial state value of the scrambling code generator is used to carry the verification information, that is, the random value is replaced by the verification information. Status value (check information), so it belongs to implicit transmission.

For example, the scrambling code generator is a 7-bit cyclic shift register. After a 7-bit initial value is given, a scrambling code sequence with a period of 127 can be output. In the traditional mechanism, the source wireless device of the transmission frame randomly selects a 7-bit binary sequence that is not all 0s as the initial state value of the scrambling code generator. In the extension method, 6 bits (X1-X6) in the check value are used to replace 6 bits in the 7-bit random sequence, and the remaining 1 bit is always set to 1 (in order to ensure that the initial state value is not all 0). After other wireless devices receive the transmission frame, they can reversely deduce the 7-bit initial state value, of which 6 bits are the content of the check value. In this method, the initial state value of the scrambling code generator implicitly carries a 6-bit check value (X1~X6), plus the 9 bits (X7~X15) directly carried by the service field, the check value can contain at most 15bits, The process is shown in Figure 2.

In this embodiment, when the source wireless device of the transmission frame sends the transmission frame, other wireless devices using the same wireless channel as the source wireless device will receive the transmission frame.

S102. Determine whether the duration is a valid duration according to the first check value.

As a possible implementation manner, the specific manner of determining whether the duration is a valid duration according to the check value is as follows:

The third check value is obtained by calculating according to a predetermined algorithm according to the field set;

When the first check value matches the third check value, the duration is determined to be a valid duration.

In this embodiment, after the transmission frame is received, it is determined whether the duration is a valid duration according to the first check value, that is, the third check value of the field set included in the received transmission frame is calculated, and the first check value is determined. Whether the value matches the third check value. Wherein, only when the check field and the field set are transmitted correctly, the first check value will match the third check value. Matching can be equal, or there is a corresponding relationship. For example, if one side is equal to the other side after inversion, it can be understood that the two sides have a corresponding relationship.

For example, it is assumed that the first check value and the third check value are both values directly calculated according to the field set using a predetermined algorithm, and the first check value matches the third check value, that is, the first check value and the third check value match. The three check values are equal; it is assumed that the first check value is the value obtained by inverting the value calculated according to the field set using a predetermined algorithm, and the third check value is the value directly calculated according to the field set using a predetermined algorithm. The check value matches the third check value, that is, the value after the inversion of the first check value is equal to the third check value or the value after the inversion of the third check value is equal to the first check value. The predetermined algorithm may be a cyclic redundancy check (Cyclic Redundancy Code, CRC) algorithm.

S103. When it is determined that the duration is a valid duration, update the NAV timer of the local end with the duration.

In this embodiment, when it is determined that the duration is a valid duration, that is, when the first check value matches the third check value, the NAV timer at the local end is updated by using the duration, that is, the time of the NAV timer is set to be equal to the duration of the duration. value, so that the local end does not send data before the time of the NAV timer is decremented to zero, so as to avoid the data sent by the local end causing interference to the data being transmitted in the same wireless channel; when the duration is an invalid duration, it will not send data. Update the NAV timer of the local end.

As a possible implementation manner, the transmission frame further includes a reception address field, the reception address field includes a reception address of the transmission frame, and the field set further includes a reception address field;

When it is determined that the duration is a valid duration, the method of using the duration to update the NAV timer of the local end is as follows:

When the duration is a valid duration, the receiving address does not match the address of the local end, and the duration is greater than the time of the network allocation vector timer of the local end, the NAV timer of the local end is updated with the duration.

In this embodiment, when the transmission frame includes the duration field and the receiving address field, the third check value is calculated according to a predetermined algorithm according to the field set, that is, the third check value is calculated according to the predetermined algorithm according to the duration field and the receiving address field. . Therefore, when the first check value matches the third check value, it can be indicated that the duration is a valid duration and the receiving address is a valid receiving address. When the first check value does not match the third check value, it may be indicated that the duration is an invalid duration, and/or the receiving address is an invalid receiving address.

In this embodiment, when the transmission frame includes a first check value, a duration and a receiving address field, after receiving the transmission frame, the first check value is used to verify whether the duration is a valid duration and whether the receiving address field is a valid duration. Effective address field, when the duration is the effective duration and the receiving address field is the effective address field, judge whether the receiving address matches the address of the local end, when the receiving address does not match the address of the local end (indicating that the transmission frame is not sent to the local end) The transmission frame of the local end), further judge whether the duration is greater than the time of the network allocation vector timer of the local end, when the duration is greater than the time of the network allocation vector timer of the local end, use the duration to update the NAV timer of the local end; when receiving the address field When it is an invalid address field, it indicates that the duration field is also an invalid field, and the NAV timer of the local end will not be updated with the duration; when the receiving address field is a valid address field and the receiving address matches the local address, it indicates that the transmission frame is The transmission frame sent to the local end continues to receive other contents of the transmission frame; when the receiving address field is a valid address field, the receiving address does not match the address of the local end, and the duration is less than or equal to the time of the network allocation vector timer of the local end, The local NAV timer will not be updated with the duration. The receiving address is the address of the destination wireless device of the transmission frame.

In this embodiment, the receiving address included in the transmission frame may be a unicast receiving address, a multicast receiving address, or a broadcast receiving address. Therefore, the matching between the address of the local end and the receiving address includes the following situations: when the receiving address is a unicast receiving address, When the unicast receiving address matches the local address, it indicates that the local address matches the receiving address; when the receiving address is the multicast receiving address, if the multicast group defined by the multicast receiving address includes the local address, it indicates that the local address is the same. The address of the terminal matches the receiving address; when the receiving address is the broadcast receiving address, it indicates that the address of the local end matches the receiving address. In other cases, it is considered that the address of the local end does not match the receiving address.

As a possible implementation manner, the transmission frame further includes a physical header, and the physical header includes indication information, and the indication information is used to indicate that the transmission frame includes a check field.

In this embodiment, when the transmission frame includes a check field, a duration, a receiving address field, and indication information, after receiving the transmission frame, the indication information is used to determine whether the transmission frame includes a check field, and when the transmission frame includes a check field When the first check value is used to verify whether the receiving address field is a valid address field, when the receiving address field is a valid address field, it is judged whether the receiving address matches the address of the local end, and when the receiving address does not match the address of the local end, Indicates that the transmission frame is not a transmission frame sent to the local end, and judges whether the duration is greater than the time of the network allocation vector timer of the local end. When the duration is greater than the time of the network allocation vector timer of the local end, use the duration to update the NAV timer of the local end ; When the transmission frame does not include the check field, the subsequent operation will not be performed; when the transmission frame includes the check field and the receiving address field is an invalid address field, it indicates that the duration field is also invalid, and the duration field will not be used. Update the NAV timer of the local end; when the transmission frame includes a check field, the receiving address field is a valid address field, and the receiving address matches the address of the local end, it indicates that the transmission frame is a transmission frame sent to the local end, and continues to receive other transmission frames. Content; when the transmission frame includes a check field, the receiving address field is a valid address field, the receiving address does not match the address of the local end, and the duration is less than or equal to the time of the network allocation vector timer of the local end, the duration update will not be used NAV timer of the local end.

In the existing method, the wireless device uses the duration to update the NAV timer of the local end only when the received transmission frame is a valid frame; when the received transmission frame is an invalid frame, the wireless device cannot set the NAV timing according to the duration. If the device is installed, it will send data on the wireless channel, so that multiple wireless devices simultaneously send data in the same wireless channel at the same time, which reduces the reliability of virtual carrier sense. In the virtual carrier sensing method provided by the embodiment of the present invention, a check field is included in the service field of the transmission frame, and the duration included in the received transmission frame is determined according to the first check value carried in the check field Whether it is a valid duration or not, no matter whether the received transmission frame is a valid frame or not, that is, it is not necessary to use FCS to determine whether the transmission frame is a valid frame or not, but only the duration included in the transmission frame needs to be checked. When it is determined that the duration included in the transmission frame is a valid duration, the NAV timer of the local end can be updated by using the duration, so that the local end does not send data before the time of the NAV timer is decremented to zero, so as to avoid the same wireless radio at the same time. In the channel, multiple wireless devices transmit data at the same time, so that the reliability of virtual carrier sense can be improved.

Please refer to FIG. 3. FIG. 3 is a flowchart of another virtual carrier sensing method disclosed in an embodiment of the present invention. The virtual carrier sensing method shown in FIG. 3 is suitable for wireless devices such as mobile phones and tablet computers. The virtual carrier sensing method shown in FIG. 3 is described from the perspective of the sending side, and relevant steps can be understood with reference to the foregoing content. As shown in FIG. 3 , the virtual carrier sensing method may include the following steps.

S301. Generate a transmission frame, where the transmission frame includes a service field and a duration field, wherein the service field includes a check field, the check field carries a second check value, and the second check value is calculated according to a predetermined algorithm according to the field set , the field set is a part of the fields included in the transmission frame, the field set includes the duration field, and the duration field includes the duration.

In this embodiment, the service field may carry the check value through the basic method or the extension method. The basic method is: the length of the service field is generally 16bits, of which 7bits is the initial value of the scrambling code generator and cannot carry information. Therefore, the remaining 9bits can be used to carry the check value. It has been proposed in the 802.11ac standard to use the 8bits in the service field. The method of carrying the check value, but the check value is the check value of the VTH-SIG-B field in the physical header. Therefore, a similar method (that is, using some or all of the remaining 9 bits) can be used to carry the field If the check value of the SIG field in the physical header needs to be carried, the field set will also include the SIG field in the physical header. The shorter the length of the check value, the easier it is to cause misjudgment. Therefore, the extended method further increases the length of the check value on the basis of the basic method. Specifically, the initial state value of the scrambling code generator of the source wireless device of the transmission frame is implicitly carried. Check value to increase the length of the check value.

For example, the scrambling code generator is a 7-bit cyclic shift register. After a 7-bit initial value is given, a scrambling code sequence with a period of 127 can be output. In the traditional mechanism, the source wireless device of the transmission frame randomly selects a 7-bit binary sequence that is not all 0s as the initial state value of the scrambling code generator. In the extension method, 6 bits (X1-X6) in the check value are used to replace 6 bits in the 7-bit random sequence, and the remaining 1 bit is always set to 1 (in order to ensure that the initial state value is not all 0). After other wireless devices receive the transmission frame, they can reversely deduce the 7-bit initial state value, of which 6 bits are the content of the check value. In this method, the initial state value of the scrambling code generator implicitly carries a 6-bit check value (X1~X6), plus the 9 bits (X7~X15) directly carried by the service field, the check value can contain at most 15bits, The process is shown in Figure 2.

As a possible implementation manner, the transmission frame further includes a reception address field, the reception address field includes a reception address of the transmission frame, and the field set further includes a reception address field.

In this embodiment, the receiving address of the transmission frame may be a unicast address, a broadcast address or a multicast address. The receiving address is the destination wireless device address of the transmission frame.

As a possible implementation manner, the transmission frame further includes a physical header, and the physical header includes indication information, and the indication information is used to indicate that the transmission frame includes a check field.

For example, when the value of the indication information in the physical header is 1, it indicates that the transmission frame includes a check field, and when the value of the indication information is 0, it indicates that the transmission frame does not include a check field.

S302. Send a transmission frame, so that the wireless device that has received the transmission frame determines whether the duration is an effective duration according to the first check value, and when the duration is determined to be an effective duration, use the duration to update the wireless device's The network allocates the vector timer, wherein the first check value is obtained after the second check value is carried in the check field and transmitted through the wireless channel. Specifically, how the wireless device that receives the transmission frame determines whether the duration is a valid duration according to the first check value can be understood by referring to the relevant contents of the foregoing embodiments.

In this embodiment, after the transmission frame is generated, the transmission frame is sent to the wireless device corresponding to the receiving address. During the sending process, due to the broadcasting characteristics of the wireless channel itself, the same wireless channel will be used by the wireless device corresponding to the receiving address. received by other wireless devices, so that these wireless devices use the first check value to determine whether the duration is a valid duration, and when the duration is determined to be a valid duration, they will use the duration to update their NAV timers to avoid the same time In the same wireless channel, multiple wireless devices transmit data at the same time.

In the virtual carrier sense method described in FIG. 3 , the generated transmission frame includes a check field, and the check field carries a second check value, which is used by other wireless devices of the same wireless channel by the wireless device corresponding to the receiving address. After receiving, it will use the first check value to verify whether the duration is a valid duration, wherein the first check value is obtained after the second check value is carried in the check field and transmitted through the wireless channel. When the time is a valid duration, their NAV timers will be updated with the duration to avoid the situation that multiple wireless devices transmit data simultaneously in the same wireless channel at the same time, thereby improving the reliability of virtual carrier sense.

Please refer to FIG. 4. FIG. 4 is a flowchart of a method for compressing a MAC frame header disclosed in an embodiment of the present invention. The MAC frame header compression method shown in FIG. 4 is suitable for wireless devices such as mobile phones and tablet computers. The MAC frame header compression method shown in FIG. 4 is described from the perspective of the transmitting side. As shown in FIG. 4 , the MAC frame header compression method may include the following steps.

S401. Construct a transmission frame. The transmission frame includes a physical header, a MAC frame header, and a frame check sequence. The MAC frame header includes the type of the transmission frame, the transmission direction of the transmission frame, and a set of address fields. The physical header includes a frame used to indicate whether the transmission frame is a Indication information for compressed transmission frames.

In this embodiment, in the IEEE 802.11 network, there are a large number of short frames with short lengths. Since the proportion of the MAC frame header in the short frame in the transmission frame is larger than that in the long frame, the short frame Reduced wireless channel utilization. One way to improve the utilization rate of the short frame wireless channel is: when a wireless device has multiple short frames to transmit, these short frames are aggregated into long frames for transmission. However, when these short frames belong to different users, they cannot be aggregated between them. Therefore, in this embodiment, the MAC frame header of the short frame is started, and the proportion of the MAC frame header in the transmission frame is reduced by compressing the address field set in the MAC frame header.

In this embodiment, the transmission frame is constructed according to the existing rules, and the transmission frame includes a physical header, a MAC frame header and a frame check sequence. The MAC frame header includes an address field set consisting of at least one address field and a frame control field, wherein the frame control field includes the type of the transmission frame and the transmission direction of the transmission frame. The frame check sequence is calculated based on the MAC frame header and frame body using a specific algorithm. Wherein, the indication information may also be located in the SERVICE domain. The SERVICE field is located before the MAC frame header.

S402. Determine the address fields that can be removed in the address field set according to the type of the transmission frame and the transmission direction of the transmission frame.

In this embodiment, the type of the transmission frame may be a control frame, a data frame, a management frame, etc., and the transmission direction of the transmission frame may be a downlink frame, an uplink frame, a direct connection frame, and the like.

In this embodiment, the control frame generally includes the sending address and the receiving address of the frame, or only includes the receiving address, and these addresses can be removed, that is, compressed. The sending address is the address of the source wireless device of the transmission frame, and the receiving address is the address of the destination wireless device of the transmission frame.

In this embodiment, data frames can be divided into direct connection frames (From DS=0, To DS=0) and downlink frames (From DS=1, To DS= 0), uplink frame (From DS=0, To DS=1) and Mesh frame (From DS=1, To DS=1), since any Mesh node can communicate freely, the address of the Mesh frame is not compressed; The uplink frame and the downlink frame include a receiving address, a sending address, and a third address. The receiving address and the sending address can be removed. When the frame body is a MAC Service Data Unit (MSDU), the third address is the source. The wireless device address or destination wireless device address (device address outside the current Wi-Fi network), so the third address cannot be compressed; when the frame body is an aggregated MSDU (Aggregate MSDU, A-MSDU), the third address is The basic service set identifier (Basic Service Set Identifier, BSSID), that is, the access point address, can be compressed. How to know whether the frame body part of the received transmission frame is MSDU or A-MSDU? In fact, there is an A-MSDU indication in the Quality of Service (Quality of Service, QoS) control (Control) field in the MAC frame header, which is used to indicate that the frame body part is A-MSDU or MSDU, which is located after the third address. Therefore, whether the third address exists or not will affect the relative position of the QoS Control field in the frame, that is, according to the position of the QoS Control field, the receiver cannot first obtain the indication of the existence of the A-MSDU through this field, and then determine whether the third address exists. . Therefore, when compressing the transmission frame, the QoS control field is mentioned before all address fields, so that the receiver can first check the indication of the existence of the A-MSDU in the QoS control field, so as to determine whether the third address is compressed. The position movement of the QoS control field may occur before or after the FCS calculation, which is not limited in this embodiment, but other devices should also perform corresponding reverse operations after receiving the transmission frame. Direct connection frame: includes the addresses of the two directly connected sites and the address of the same access point associated with the two sites, all three of which can be compressed.

In this embodiment, the management frame includes a receiving address, a sending address, and a third address, wherein the receiving address and the sending address may be compressed, and the third address may be a BSSID (address of an access point) or a wildcard BSSID. The BSSID cannot be compressed. Therefore, there are two schemes for compressing the address field set of the management frame: A) only the receiving address and the sending address are compressed, and the third address is always not compressed; B) when the third address is BSSID, all three address fields are compressed; when the third address is BSSID, all three address fields are compressed; When the three addresses are wildcard BSSIDs, the three address fields are not compressed. Since the third address in the actual network is mostly the BSSID, solution B is the preferred solution.

In this embodiment, when a plurality of wireless devices are associated with the local end, in order to quickly determine the identity of the transmitting end and reduce the number of attempts, some auxiliary mechanisms may be used. A basic solution is to compress only one or more of these addresses, and not compress other addresses. For example, in an uplink frame or a downlink frame, the receiving address is reserved, while the sending address is compressed; in the direct connection frame, the source site or destination is reserved. address of the site, while compressing the address of the other site and the address of the access point. In addition, while compressing the address field set, the physical header or MAC header of the transmission frame can carry a short identifier of the sender device, such as an association identifier (Association Identifier, AID), a partial association identifier (Partial AID, PAID), etc. .

In this embodiment, if the transmission frame includes an aggregated MAC protocol data unit (A-MPDU), the above-mentioned address field removal rule is applied to all MAC protocol data units (MAC protocol data units) in the A-MPDU. unit, MPDU).

S403. Remove addresses that can be removed in the address field set to obtain a compressed MAC frame header.

S404. Set the indication information in the physical header, so that the indication information is used to indicate that the transmission frame is a compressed transmission frame, so as to obtain the compressed transmission frame.

In this embodiment, the physical header includes a SIG field, which includes indication information for indicating whether the transmission frame is a compressed transmission frame. For example, when the value of the indication information is 1, it means that the transmission frame is a compressed transmission frame, and when the value of the indication information is 0, it means that the transmission frame is an uncompressed transmission frame.

S405. Send a compressed transmission frame.

In the MAC frame header compression method shown in Figure 4, before sending the transmission frame, some or all of the address fields in the MAC frame header address field set are removed to reduce the length of the MAC frame header of the transmission frame and reduce the MAC frame size. The proportion that the header occupies in the transmission frame, thereby improving the channel utilization.

Please refer to FIG. 5. FIG. 5 is a flowchart of another MAC frame header compression method disclosed by an embodiment of the present invention. The MAC frame header compression method shown in FIG. 5 is suitable for wireless devices such as mobile phones and tablet computers. The MAC frame header compression method shown in FIG. 5 is described from the perspective of the receiving side. As shown in FIG. 5 , the MAC frame header compression method may include the following steps.

S501. Receive a transmission frame. The transmission frame includes a physical header, a MAC frame header, and a frame check sequence. The MAC frame header includes the type of the transmission frame, the transmission direction of the transmission frame, and an address field set. The physical header includes indication information, and the indication information is used for Indicates that the transmission frame is a compressed transmission frame.

In this embodiment, in the IEEE 802.11 network, there are a large number of short frames with short lengths. Since the proportion of the MAC frame header in the short frame in the transmission frame is larger than that in the long frame, the short frame Reduced wireless channel utilization. One way to improve the utilization rate of the short frame wireless channel is: when a wireless device has multiple short frames to transmit, these short frames are aggregated into long frames for transmission. However, when these short frames belong to different users, they cannot be aggregated between them. Therefore, in this embodiment, the MAC frame header of the short frame is started, and the proportion of the MAC frame header in the transmission frame is reduced by compressing the address field in the MAC frame header. Wherein, the indication information may also be located in the SERVICE domain. The SERVICE field is located before the MAC frame header.

S502. Determine whether the transmission frame is a compressed transmission frame according to the indication information.

In this embodiment, since recovery processing needs to be performed after the compressed transmission frame is received, when the transmission frame is not a compressed transmission frame, recovery processing is not required. Therefore, indication information is included in the SIG field in the physical header of the transmission frame, using It is used to indicate whether the transmission frame is a compressed transmission frame. For example, when the Compress bit of the SIG field is 1, it indicates that the transmission frame is a compressed transmission frame, and when the Compress bit of the SIG field of the transmission frame is 0, it indicates that the transmission frame is not a compressed transmission frame. The type of the transmission frame may be a control frame, a data frame, a management frame, etc., and the transmission direction of the transmission frame may be a downlink frame, an uplink frame, a direct connection frame, and the like.

S503. When the transmission frame is a compressed transmission frame, determine the removed addresses in the address field set according to the type of the transmission frame and the transmission direction of the transmission frame.

In this embodiment, after the transmission frame is received, it is determined whether the transmission frame is a compressed transmission frame according to the indication information, and when the transmission frame is a compressed transmission frame, the type of the transmission frame and the transmission direction of the transmission frame are used to determine whether the address field is set to be shifted or not. except the address.

S504. Add the removed address to obtain the decompressed transmission frame.

Any one or more of the receive address, the transmit address, and the third address in the transmission frame may be compressed. Here, taking the simultaneous compression of the receiving address and the sending address as an example, how the receiving end recovers the compressed address field is described. Other cases are handled in a similar manner, and details are not repeated here.

When the removed address is composed of the receiving address of the transmission frame and the sending address of the transmission frame, adding the removed address to obtain the decompressed transmission frame may include the following steps.

A1. Use the address of the wireless device associated with the local end as the sending address of the transmission frame, and use the address of the local end as the receiving address of the transmission frame, so as to obtain the transmission frame including the removed address.

A2. Calculate the target frame check sequence of the transmission frame including the removed address.

A3. Determine whether the target frame check sequence matches the frame check sequence included in the transmission frame. When the target frame check sequence matches the frame check sequence, the transmission frame including the removed address is used as the decompressed transmission frame.

In this embodiment, when the removed address consists of the address of the sending device of the transmission frame and the receiving address of the transmission frame, it is assumed that the address of the wireless device associated with the local end is the sending address of the transmission frame, and the address of the local end is The receiving address of the transmission frame to obtain the transmission frame including the removed address, then use the cyclic redundancy algorithm to calculate the target frame check sequence of the transmission frame including the removed address, and then determine that the target frame check sequence and the transmission frame include Whether the frame check sequence is matched, when the target frame check sequence matches the frame check sequence included in the transmission frame, it indicates that the assumption is true, the transmission frame is the transmission frame sent by the associated wireless device to the local end, and will include the shifted frame. The transmission frame except the address is used as the decompressed transmission frame; when the target frame check sequence does not match the frame check sequence, it indicates that the assumption does not hold, and the transmission frame is not the transmission frame sent by the associated wireless device to the local end. When the wireless devices connected to the local end are multiple wireless devices, the above operations will be performed multiple times until the matching is successful or all wireless devices connected to the local end are tried.

In this embodiment, when a plurality of wireless devices are associated with the local end, in order to quickly determine the identity of the transmitting end and reduce the number of attempts, some auxiliary mechanisms may be used. A basic solution is to compress only one or more of these addresses, and not compress other addresses. For example, in an uplink frame or a downlink frame, the receiving address is reserved, while the sending address is compressed; in the direct connection frame, the source site or destination is reserved. address of the site, while compressing the address of the other site and the address of the access point. In addition, while compressing the address field set, the physical header or MAC header of the transmission frame may carry a short identifier of the sending end device, such as AID, PAID, and the like.

In the MAC frame header compression method shown in Figure 5, when the transmission frame is a compressed frame, some or all addresses in the MAC frame header address field set are removed, and the length of the MAC frame header of the transmission frame is reduced, so that the MAC frame The proportion of the header in the transmission frame is reduced, thereby improving the channel utilization.

Please refer to FIG. 6. FIG. 6 is a structural diagram of a wireless device disclosed in an embodiment of the present invention. The wireless device may be a mobile phone, a tablet computer, or the like, which is not limited in this embodiment. As shown in FIG. 6, the wireless device 600 may include:

The receiving unit 601 is configured to receive a transmission frame, where the transmission frame includes a service field and a duration field, wherein the service field includes a check field, and the check field carries a first check value, and the first check value is the second check value. The check value is carried in the check field and obtained after being transmitted through the wireless channel, and the second check value is calculated according to a predetermined algorithm according to the field set when the wireless device sending the transmission frame generates the transmission frame; wherein, the field set is the transmission frame. Some of the fields included, the field set includes the duration field; the duration field includes the duration;

Judging unit 602, configured to determine whether the duration is a valid duration according to the first check value included in the transmission frame received by the receiving unit 601;

The updating unit 603 is configured to update the NAV timer of the wireless device with the duration included in the transmission frame received by the receiving unit 601 when the judging unit 602 determines that the duration is a valid duration.

Specifically, the updating unit 603 is specifically configured to use the duration to update the NAV timer of the wireless device when the determination unit 602 determines that the duration is an effective duration.

As a possible implementation manner, the judging unit 602 is specifically used for:

The third check value is obtained by calculating according to a predetermined algorithm according to the field set;

When the first check value matches the third check value, the duration is determined to be a valid duration.

As a possible implementation manner, the transmission frame further includes a reception address field, the reception address field includes a reception address of the transmission frame, and the field set further includes a reception address field;

The updating unit 603 is specifically configured to, according to the first check value, determine that the duration is a valid duration and the receiving address is a valid receiving address, if the receiving address does not match the address of the wireless device, and the duration is greater than the duration of the wireless device. When the time of the network allocation vector timer is reached, the network allocation vector timer of the wireless device is updated with the duration.

As a possible implementation manner, the transmission frame further includes a physical header, and the physical header includes indication information, and the indication information is used to indicate that the transmission frame includes a check field.

In the existing method, the wireless device uses the duration to update the NAV timer of the local end only when the receiving address is a valid address and the receiving address does not match the address of the local end, and if the transmission frame is a valid frame; when the received transmission frame is invalid. frame, the wireless device cannot set the NAV timer according to the duration, and will send data on the wireless channel, so that multiple wireless devices simultaneously send data in the same wireless channel at the same time, reducing the reliability of virtual carrier sense. . In the virtual carrier sensing method provided by the embodiment of the present invention, a check field is included in the service field of the transmission frame, and the duration included in the received transmission frame is determined according to the first check value carried in the check field Whether it is a valid duration, whether the receiving address included in the received transmission frame is a valid receiving address, regardless of whether the received transmission frame is a valid frame, that is, it is not necessary to use FCS to judge whether the transmission frame is a valid frame or not for the entire frame of the transmission frame. It is necessary to verify the receiving address and duration included in the transmission frame. When the receiving address is a valid receiving address and the receiving address does not match the address of the local end, it is determined that the duration included in the transmission frame is the valid duration. Use the duration to update the NAV timer of the local end, so that the local end does not send data before the time of the NAV timer is decremented to zero, so as to avoid the situation that multiple wireless devices send data simultaneously in the same wireless channel at the same time. Virtual carrier sense reliability.

Please refer to FIG. 7, which is a structural diagram of another wireless device disclosed in an embodiment of the present invention. The wireless device may be a mobile phone, a tablet computer, or the like, which is not limited in this embodiment. As shown in FIG. 7 , the wireless device 700 may include a processor 701 , a memory 702 , an input device 703 and an output device 704 . The processor 701 and the memory 702, the processor 701 and the input device 703, and the processor 701 and the output device 704 may be connected through a bus or other means, and the bus connection is taken as an example in this embodiment. in:

The input device 703 is configured to receive a transmission frame and send it to the processor 701. The transmission frame includes a service field and a duration field, wherein the service field includes a check field, and the check field carries a first check value, and the first check value is included in the check field. The check value is obtained after the second check value is carried in the check field and transmitted through the wireless channel, and the second check value is calculated according to a predetermined algorithm according to the field set when the wireless device sending the transmission frame generates the transmission frame; wherein , the field set is part of the fields included in the transmission frame, the field set includes the duration field; the duration field includes the duration;

A set of program codes are stored in the memory 702, and the processor 701 is configured to call the program codes stored in the memory 702 to perform the following operations:

determining whether the duration is a valid duration according to the first check value;

When the duration is determined to be a valid duration, the NAV timer of the wireless device is updated with the duration.

As a possible implementation manner, the output device 704 is used for sending a message.

As a possible implementation manner, the manner in which the processor 701 determines whether the duration is a valid duration according to the first check value is specifically:

The processor 701 is configured to calculate and obtain a third check value according to a predetermined algorithm according to the field set;

When the first check value matches the third check value, the duration is determined to be a valid duration.

As a possible implementation manner, the transmission frame further includes a reception address field, the reception address field includes a reception address of the transmission frame, and the field set further includes a reception address field;

The manner in which the processor 701 is configured to update the network allocation vector timer of the wireless device with the duration when it is determined that the duration is a valid duration is as follows:

The processor 701 is configured to, when it is determined according to the first check value that the duration is a valid duration and the receiving address is a valid receiving address, if the receiving address does not match the address of the wireless device, and the duration is greater than the network allocation of the wireless device The time of the vector timer is used to update the network allocation vector timer of the wireless device with the duration.

As a possible implementation manner, the transmission frame further includes a physical header, and the physical header includes indication information, and the indication information is used to indicate that the transmission frame includes a check field.

In the existing method, the wireless device uses the duration to update the NAV timer of the local end only when the receiving address is a valid address and the receiving address does not match the address of the local end, and if the transmission frame is a valid frame; when the received transmission frame is invalid. frame, the wireless device cannot set the NAV timer according to the duration, and will send data on the wireless channel, so that multiple wireless devices simultaneously send data in the same wireless channel at the same time, reducing the reliability of virtual carrier sense. . In the virtual carrier sensing method provided by the embodiment of the present invention, a check field is included in the service field of the transmission frame, and the duration included in the received transmission frame is determined according to the first check value carried in the check field Whether it is a valid duration, whether the receiving address included in the received transmission frame is a valid receiving address, regardless of whether the received transmission frame is a valid frame, that is, it is not necessary to use FCS to judge whether the transmission frame is a valid frame or not for the entire frame of the transmission frame. It is necessary to verify the receiving address and duration included in the transmission frame. When the receiving address is a valid receiving address and the receiving address does not match the address of the local end, it is determined that the duration included in the transmission frame is the valid duration. Use the duration to update the NAV timer of the local end, so that the local end does not send data before the time of the NAV timer is decremented to zero, so as to avoid the situation that multiple wireless devices send data simultaneously in the same wireless channel at the same time. Virtual carrier sense reliability.

Please refer to FIG. 8. FIG. 8 is a structural diagram of another wireless device disclosed in an embodiment of the present invention. The wireless device may be a mobile phone, a tablet computer, or the like, which is not limited in this embodiment. As shown in FIG. 8, the wireless device 800 may include:

The generating unit 801 is configured to generate a transmission frame, where the transmission frame includes a service field and a duration field, wherein the service field includes a check field, and the check field carries a second check value, and the second check value is selected according to the field set. Calculated by the predetermined algorithm, the field set is a part of the fields included in the transmission frame, the field set includes the duration field, and the duration field includes the duration;

The sending unit 802 is configured to send the transmission frame generated by the generating unit 801, so that the target wireless device that receives the transmission frame determines whether the duration is an effective duration according to the first check value, and when the determined duration is an effective duration When , the network allocation vector timer of the target wireless device is updated with the duration, wherein the first check value is obtained after the second check value is carried in the check field and transmitted through the wireless channel.

As a possible implementation manner, the transmission frame further includes a reception address field, the reception address field includes a reception address of the transmission frame, and the field set further includes a reception address field.

As a possible implementation manner, the transmission frame further includes a physical header, and the physical header includes indication information, and the indication information is used to indicate that the transmission frame includes a check field.

In the wireless device described in FIG. 8 , the generated transmission frame includes a check field, and the check field carries a second check value, which is received by other wireless devices using the same wireless channel by the wireless device corresponding to the receiving address. , will use the first check value to verify whether the duration is a valid duration, wherein, the first check value is obtained after the second check value is carried in the check field and transmitted through the wireless channel, when the duration is valid When the duration is set, their NAV timers will be updated with the duration to avoid the situation that multiple wireless devices transmit data simultaneously in the same wireless channel at the same time, thereby improving the reliability of virtual carrier sense.

Please refer to FIG. 9. FIG. 9 is a structural diagram of another wireless device disclosed in an embodiment of the present invention. The wireless device may be a mobile phone, a tablet computer, or the like, which is not limited in this embodiment. As shown in FIG. 9 , the wireless device 900 may include a processor 901 , a memory 902 , an output device 903 and an input device 904 . The processor 901 and the memory 902, the processor 901 and the input device 903, and the processor 901 and the input device 904 may be connected through a bus or other means, and the bus connection is taken as an example in this embodiment. in:

A set of program codes are stored in the memory 902, and the processor 901 is configured to call the program codes stored in the memory 902 to perform the following operations:

A transmission frame is generated, and the transmission frame includes a service field and a duration field, wherein the service field includes a check field, and the check field carries a second check value, and the second check value is calculated according to a predetermined algorithm according to the field set, and the field The set is a part of the fields included in the transmission frame, the field set includes the duration field, and the duration field includes the duration;

The output device 903 is configured to send the transmission frame, so that the target wireless device that receives the transmission frame determines whether the duration is a valid duration according to the first check value, and when it is determined that the duration is a valid duration, utilizes the duration The network allocation vector timer of the target wireless device is updated, wherein the first check value is obtained after the second check value is carried in the check field and transmitted through the wireless channel.

As a possible implementation manner, the wireless device 900 may further include an input device 904 for receiving a message.

As a possible implementation manner, the transmission frame further includes a reception address field, the reception address field includes a reception address of the transmission frame, and the field set further includes a reception address field.

As a possible implementation manner, the transmission frame further includes a physical header, and the physical header includes indication information, and the indication information is used to indicate that the transmission frame includes a check field.

In the wireless device shown in FIG. 9 , the generated transmission frame includes a check field, and the check field carries a second check value, which is received by other wireless devices using the same wireless channel by the wireless device corresponding to the receiving address. , will use the first check value to verify whether the duration is a valid duration, wherein, the first check value is obtained after the second check value is carried in the check field and transmitted through the wireless channel, when the duration is valid When the duration is set, their NAV timers will be updated with the duration to avoid the situation that multiple wireless devices transmit data simultaneously in the same wireless channel at the same time, thereby improving the reliability of virtual carrier sense.

Please refer to FIG. 10. FIG. 10 is a structural diagram of another wireless device disclosed in an embodiment of the present invention. The wireless device may be a mobile phone, a tablet computer, or the like, which is not limited in this embodiment. As shown in FIG. 10, the wireless device 1000 may include:

The construction unit 1001 is used for constructing a transmission frame, the transmission frame includes a physical header, a MAC frame header and a frame check sequence, the MAC frame header includes the type of the transmission frame, the transmission direction of the transmission frame and the set of address fields, and the physical header includes an indicator for indicating Indication information of whether the transmission frame is a compressed transmission frame;

determining unit 1002, for determining the address fields that can be removed in the address field set according to the type of the transmission frame constructed by the construction unit 1001 and the transmission direction of the transmission frame constructed by the construction unit 1001;

The removing unit 1003 is used to remove the address that can be removed determined by the address field set determination unit 1002 constructed by the constructing unit 1001 to obtain the compressed MAC frame header;

The obtaining unit 1004 is used to set the indication information in the physical header included in the transmission frame constructed by the construction unit 1001, so that the indication information is used to indicate that the transmission frame is a compressed transmission frame, so as to obtain the compressed transmission frame;

The sending unit 1005 sends the compressed transmission frame obtained by the obtaining unit 1004 .

Specifically, the removing unit 1003 is configured to remove the addresses that can be removed and determined by the determination unit 1002 in the address field set constructed by the constructing unit 1001, to acquire the compressed MAC frame header, and trigger the acquiring unit 1004 to set the address constructed by the constructing unit 1001. The indication information in the physical header included in the transmission frame, so that the indication information is used to indicate that the transmission frame is a compressed transmission frame, so as to obtain the compressed transmission frame

In the wireless device shown in Figure 10, before sending a transmission frame, some or all of the address fields in the MAC frame header address field set are removed to reduce the length of the MAC frame header of the transmission frame and reduce the length of the MAC frame header during transmission. The proportion occupied in the frame, thereby improving the channel utilization.

Please refer to FIG. 11. FIG. 11 is a structural diagram of another wireless device disclosed in an embodiment of the present invention. The wireless device may be a mobile phone, a tablet computer, or the like, which is not limited in this embodiment. As shown in FIG. 11 , the wireless device 1100 may include a processor 1101 , a memory 1102 , an output device 1103 and an input device 1104 . The processor 1101 and the memory 1102, the processor 1101 and the output device 1103, and the processor 1101 and the input device 1104 may be connected through a bus or other means, and the bus connection is taken as an example in this embodiment. in:

A set of program codes are stored in the memory 1102, and the processor 1101 is configured to call the program codes stored in the memory 1102 to perform the following operations:

Construct a transmission frame. The transmission frame includes a physical header, a MAC frame header, and a frame check sequence. The MAC frame header includes the type of the transmission frame, the transmission direction of the transmission frame, and the set of address fields. The physical header includes a frame used to indicate whether the transmission frame is compressed transmission. Indication information of the frame;

Determine the address fields that can be removed in the address field set according to the type of the transmission frame and the transmission direction of the transmission frame;

Remove the addresses that can be removed from the address field set to obtain the compressed MAC frame header;

Set the indication information in the physical header, so that the indication information is used to indicate that the transmission frame is a compressed transmission frame, so as to obtain the compressed transmission frame;

The output device 1103 is used for sending the compressed transmission frame.

As a possible implementation manner, the input device 1104 is used to receive messages.

In the wireless device shown in Figure 11, before sending a transmission frame, some or all of the address fields in the MAC frame header address field set are removed to reduce the length of the MAC frame header of the transmission frame and reduce the length of the MAC frame header during transmission. The proportion occupied in the frame, thereby improving the channel utilization.

Please refer to FIG. 12. FIG. 12 is a structural diagram of another wireless device disclosed in an embodiment of the present invention. The wireless device may be a mobile phone, a tablet computer, or the like, which is not limited in this embodiment. As shown in Figure 12, the wireless device 1200 may include:

The receiving unit 1201 is configured to receive a transmission frame, the transmission frame includes a physical header, a MAC frame header and a frame check sequence, the MAC frame header includes the type of the transmission frame, the transmission direction and address field set of the transmission frame, and the physical header includes indication information, The indication information is used to indicate that the transmission frame is a compressed transmission frame;

Judging unit 1202, for judging whether the transmission frame is a compressed transmission frame according to the indication information received by the receiving unit 1201;

Determining unit 1203, for when the judgment result of judging unit 1202 is yes, utilize the type of the transmission frame that the receiving unit 1201 obtains and the transmission direction of the transmission frame that the receiving unit 1201 obtains to determine the removed address in the field set;

The adding unit 1204 is configured to add the removed address determined by the determining unit 1203 to obtain the decompressed transmission frame.

As a possible implementation manner, when the removed address is composed of the receiving address of the transmission frame and the sending address of the transmission frame, the adding unit 1204 may include:

The address obtaining subunit is used for taking the address of the target wireless device associated with the wireless device as the sending address of the transmission frame, and the address of the wireless device as the receiving address of the transmission frame, so as to obtain the transmission frame including the removed address.

The sequence acquisition subunit is configured to calculate the target frame check sequence of the transmission frame including the removed address acquired by the address acquisition subunit.

The judging subunit is used to judge whether the target frame check sequence obtained by the sequence obtaining subunit matches the frame check sequence included in the transmission frame received by the receiving unit 1201. When the judgment result of the judging subunit is yes, it will include The transport frame except the address is used as the decompressed transport frame.

In the wireless device shown in Figure 12, when the transmission frame is a compressed frame, some or all of the address fields in the MAC header address field set are removed, and the length of the MAC header of the transmission frame is reduced, so that the MAC header is in the The proportion occupied in the transmission frame is reduced, thereby improving the channel utilization rate.

Please refer to FIG. 13. FIG. 13 is a structural diagram of another wireless device disclosed in an embodiment of the present invention. The wireless device may be a mobile phone, a tablet computer, or the like, which is not limited in this embodiment. As shown in FIG. 13 , the wireless device 1300 may include a processor 1301 , a memory 1302 , an input device 1303 and an output device 1304 . The processor 1301 and the memory 1302, the processor 1301 and the input device 1303, and the processor 1301 and the output device 1304 may be connected through a bus or other means, and this embodiment takes the bus connection as an example. in:

The input device 1303 is configured to receive a transmission frame, the transmission frame includes a physical header, a MAC frame header and a frame check sequence, the MAC frame header includes the type of the transmission frame, the transmission direction of the transmission frame and an address field set, and the physical header includes indication information, The indication information is used to indicate that the transmission frame is a compressed transmission frame;

A set of program codes are stored in the memory 1302, and the processor 1301 is configured to call the program codes stored in the memory 1302 to perform the following operations:

Determine whether the transmission frame is a compressed transmission frame according to the indication information;

When the transmission frame is a compressed transmission frame, the removed addresses in the address field set are determined according to the type of the transmission frame and the transmission direction of the transmission frame;

Add the removed address to get the decompressed transport frame.

As a possible implementation manner, the output device 1304 is used for sending a message.

As a possible implementation manner, when the removed address is composed of the receiving address of the transmission frame and the sending address of the transmission frame, the processor 1301 adds the removed address to obtain the decompressed transmission frame. Specifically:

Using the address of the target wireless device associated with the wireless device as the sending address of the transmission frame, and using the address of the wireless device as the receiving address of the transmission frame, to obtain the transmission frame including the removed address;

Calculate the target frame check sequence of the transmission frame including the removed address;

It is judged whether the target frame check sequence matches the frame check sequence included in the transmission frame. If the target frame check sequence matches the frame check sequence, the transmission frame including the removed address is used as the decompressed transmission frame.

In the wireless device shown in Figure 13, when the transmission frame is a compressed frame, some or all of the addresses in the MAC header address field set are removed, and the length of the MAC header of the transmission frame is reduced, so that the MAC header is transmitted The proportion occupied in the frame is reduced, thereby improving the channel utilization.

In one embodiment, the embodiment of the present invention further discloses a computer storage medium, the computer storage medium stores a computer program, and when the computer program in the computer storage medium is read to a computer, the computer can be made to complete the disclosure of the embodiment of the present invention. All steps of the virtual carrier sense method.

It should be noted that, for the sake of simple description, the foregoing method embodiments are all expressed as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence. As in accordance with the present invention, certain steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium, and the storage medium can include: Flash disk, read-only memory (Read-Only Memory, ROM), random access device (Random Access Memory, RAM), magnetic disk or optical disk, etc.

The virtual carrier sensing method and device provided by the embodiments of the present invention have been described in detail above. The principles and implementations of the present invention are described in this paper by using specific examples. The descriptions of the above embodiments are only used to help understand the present invention. At the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be construed as Limitations of the present invention.

Claims (26)

1. A virtual carrier sensing method, comprising:

receiving a transmission frame, wherein the transmission frame comprises a service field and a duration field, the service field comprises a check field, the check field carries a first check value, the first check value is obtained after a second check value is carried in the check field and transmitted through a wireless channel, and the second check value is obtained by calculation according to a field set and a preset algorithm when a wireless device sending the transmission frame generates the transmission frame; wherein the field set is a partial field of fields included in the transmission frame, the field set including the duration field; the duration field comprises a duration;

determining whether the duration is a valid duration according to the first check value;

and when the duration is determined to be the valid duration, updating the network allocation vector timer of the local terminal by using the duration.

2. The method of claim 1, wherein said determining whether the duration is a valid duration based on the first check value comprises:

calculating according to the field set and the preset algorithm to obtain a third check value;

determining the duration as a valid duration when the first check value matches the third check value.

3. The method of claim 1, wherein the transmission frame further comprises a receive address field, the receive address field comprising a receive address of the transmission frame, the set of fields further comprising the receive address field;

when the duration is determined to be the valid duration, updating the local network allocation vector timer by using the duration comprises:

and when the duration is determined to be the valid duration and the receiving address is determined to be the valid receiving address according to the first check value, if the receiving address is not matched with the address of the local terminal and the duration is greater than the time of the network allocation vector timer of the local terminal, updating the network allocation vector timer of the local terminal by using the duration.

4. The method of claim 2, wherein the transmission frame further comprises a receive address field, the receive address field comprising a receive address of the transmission frame, the set of fields further comprising the receive address field;

when the duration is determined to be the valid duration, updating the local network allocation vector timer by using the duration comprises:

and when the duration is determined to be the valid duration and the receiving address is determined to be the valid receiving address according to the first check value, if the receiving address is not matched with the address of the local terminal and the duration is greater than the time of the network allocation vector timer of the local terminal, updating the network allocation vector timer of the local terminal by using the duration.

5. The method of any of claims 1-4, wherein the transmission frame further comprises a physical header, the physical header comprising indication information indicating that the transmission frame includes the check field.

6. A virtual carrier sensing method, comprising:

generating a transmission frame, wherein the transmission frame comprises a service field and a duration field, the service field comprises a check field, the check field carries a second check value, the second check value is calculated according to a field set according to a predetermined algorithm, the field set is a part of fields in the fields included in the transmission frame, the field set comprises the duration field, and the duration field comprises a duration;

and transmitting the transmission frame so that the wireless device receiving the transmission frame determines whether the duration is the valid duration according to a first check value, and updating a network allocation vector timer of the wireless device by using the duration when the duration is determined to be the valid duration, wherein the first check value is obtained after the second check value is carried in the check field and transmitted through a wireless channel.

7. The method of claim 6, wherein the transmission frame further comprises a receive address field, the receive address field comprising a receive address of the transmission frame, the set of fields further comprising the receive address field.

8. The method of claim 6 or 7, wherein the transmission frame further comprises a physical header, the physical header comprising indication information for indicating that the transmission frame comprises the check field.

9. A wireless device, comprising:

a receiving unit, configured to receive a transmission frame, where the transmission frame includes a service field and a duration field, where the service field includes a check field, the check field carries a first check value, the first check value is obtained after a second check value is carried in the check field and transmitted through a wireless channel, and the second check value is calculated according to a field set according to a predetermined algorithm when a wireless device that sends the transmission frame generates the transmission frame; wherein the field set is a partial field of fields included in the transmission frame, the field set including the duration field; the duration field comprises a duration;

a judging unit, configured to determine whether the duration is a valid duration according to a first check value included in the transmission frame received by the receiving unit;

and the updating unit is used for updating the network allocation vector timer of the wireless equipment by using the duration when the judging unit determines that the duration is the valid duration.

10. The wireless device of claim 9, wherein the determining unit is specifically configured to:

calculating according to the field set and the preset algorithm to obtain a third check value;

determining the duration as a valid duration when the first check value matches the third check value.

11. The wireless device of claim 9, wherein the transmission frame further comprises a receive address field, the receive address field comprising a receive address of the transmission frame, the set of fields further comprising the receive address field;

the updating unit is specifically configured to, when it is determined according to the first check value that the duration is a valid duration and the receiving address is a valid receiving address, update the network allocation vector timer of the wireless device by using the duration if the receiving address is not matched with the address of the wireless device and the duration is greater than the time of the network allocation vector timer of the wireless device.

12. The wireless device of claim 10, wherein the transmission frame further comprises a receive address field, the receive address field comprising a receive address of the transmission frame, the set of fields further comprising the receive address field;

the updating unit is specifically configured to, when it is determined according to the first check value that the duration is a valid duration and the receiving address is a valid receiving address, update the network allocation vector timer of the wireless device by using the duration if the receiving address is not matched with the address of the wireless device and the duration is greater than the time of the network allocation vector timer of the wireless device.

13. The wireless device of any of claims 9-12, wherein the transmission frame further comprises a physical header, the physical header comprising indication information indicating that the transmission frame includes the check field.

14. A wireless device comprising a processor, a memory, and an input, wherein:

the input device is configured to receive a transmission frame and send the transmission frame to the processor, where the transmission frame includes a service field and a duration field, where the service field includes a check field, and the check field carries a first check value, the first check value is obtained after a second check value is carried in the check field and transmitted through a wireless channel, and the second check value is calculated according to a field set according to a predetermined algorithm when a wireless device sending the transmission frame generates the transmission frame; wherein the field set is a partial field of fields included in the transmission frame, the field set including the duration field; the duration field comprises a duration;

the memory has stored therein a set of program code, and the processor is configured to invoke the program code stored in the memory to perform the following operations:

determining whether the duration is a valid duration according to the first check value;

updating a network allocation vector timer of the wireless device with the duration when the duration is determined to be a valid duration.

15. The wireless device of claim 14, wherein the processor is configured to determine whether the duration is a valid duration based on the first check value by:

the processor is used for calculating a third check value according to the field set and the preset algorithm;

determining the duration as a valid duration when the first check value matches the third check value.

16. The wireless device of claim 14, wherein the transmission frame further comprises a receive address field, the receive address field comprising a receive address of the transmission frame, the set of fields further comprising the receive address field;

the processor is configured to, when it is determined that the duration is the valid duration, update the network allocation vector timer of the wireless device using the duration in a specific manner:

the processor is configured to update the network allocation vector timer of the wireless device with the duration if the received address does not match the address of the wireless device and the duration is greater than the time of the network allocation vector timer of the wireless device when it is determined that the duration is a valid duration and the received address is a valid received address according to the first check value.

17. The wireless device of claim 15, wherein the transmission frame further comprises a receive address field, the receive address field comprising a receive address of the transmission frame, the set of fields further comprising the receive address field;

the processor is configured to, when it is determined that the duration is the valid duration, update the network allocation vector timer of the wireless device using the duration in a specific manner:

the processor is configured to update the network allocation vector timer of the wireless device with the duration if the received address does not match the address of the wireless device and the duration is greater than the time of the network allocation vector timer of the wireless device when it is determined that the duration is a valid duration and the received address is a valid received address according to the first check value.

18. The wireless device of any of claims 14-17, wherein the transmission frame further comprises a physical header, the physical header comprising indication information indicating that the transmission frame includes the check field.

19. A wireless device, comprising:

a generating unit, configured to generate a transmission frame, where the transmission frame includes a service field and a duration field, where the service field includes a check field, the check field carries a second check value, the second check value is calculated according to a field set according to a predetermined algorithm, the field set is a partial field in fields included in the transmission frame, the field set includes the duration field, and the duration field includes a duration;

a sending unit, configured to send the transmission frame generated by the generating unit, so that a target wireless device that receives the transmission frame determines whether the duration is a valid duration according to a first check value, and when it is determined that the duration is the valid duration, updates a network allocation vector timer of the target wireless device by using the duration, where the first check value is obtained after the second check value is carried in the check field and transmitted through a wireless channel.

20. The wireless device of claim 19, wherein the transmission frame further comprises a receive address field, the receive address field comprising a receive address of the transmission frame, the set of fields further comprising the receive address field.

21. The wireless device of claim 19 or 20, wherein the transmission frame further comprises a physical header, the physical header comprising indication information indicating that the transmission frame includes the check field.

22. A wireless device comprising a processor, a memory, and an output, wherein:

the memory has stored therein a set of program code, and the processor is configured to invoke the program code stored in the memory to perform the following operations:

generating a transmission frame, wherein the transmission frame comprises a service field and a duration field, the service field comprises a check field, the check field carries a second check value, the second check value is calculated according to a field set according to a predetermined algorithm, the field set is a part of fields in the fields included in the transmission frame, the field set comprises the duration field, and the duration field comprises a duration;

and the output device is configured to send the transmission frame, so that a target wireless device that receives the transmission frame determines whether the duration is a valid duration according to a first check value, and updates a network allocation vector timer of the target wireless device by using the duration when the duration is determined to be the valid duration, where the first check value is obtained after the second check value is carried in the check field and transmitted through a wireless channel.

23. The wireless device of claim 22, wherein the transmission frame further comprises a receive address field, the receive address field comprising a receive address of the transmission frame, the set of fields further comprising the receive address field.

24. The wireless device of claim 22 or 23, wherein the transmission frame further comprises a physical header, the physical header comprising indication information indicating that the transmission frame includes the check field.

25. A computer-readable storage medium, characterized in that it stores a computer program which, when executed by associated hardware, carries out the method of any one of claims 1 to 5.

26. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program which, when executed by associated hardware, performs the method of any one of claims 6 to 8.

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