WO2016082230A1

WO2016082230A1 - Virtual carrier sensing method and device

Info

Publication number: WO2016082230A1
Application number: PCT/CN2014/092624
Authority: WO
Inventors: 杜振国; 丁志明
Original assignee: 华为技术有限公司
Priority date: 2014-11-29
Filing date: 2014-11-29
Publication date: 2016-06-02
Also published as: CN106471785B; CN106471785A

Abstract

A virtual carrier sensing method and device, the method comprising: receiving a transmission frame comprising a service field and a duration field, and the service field comprises a verification field, the verification field carries a first verification value obtained from a second verification value carried in a verification field transmitted through a wireless channel, and the second verification value is from a field set calculated according to a preset algorithm when a wireless device transmitting the transmission frame generates the transmission frame; the field set is a part of the fields included in the transmission frame, the field set comprises the duration field; the duration field comprises a duration time (S101); determining whether the duration time is an effective duration time according to the first verification value (S102); when the duration time is determined to be an effective duration time, updating a local network allocation vector (NAV) timer using the duration time (S103). The method can improve the reliability of the virtual carrier sensing.

Description

Virtual carrier sensing method and device

Technical field

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

Background technique

Virtual Carrier Sense (VCS) is an important transmission protection mechanism in the 802.11 standard of the Institute of Electrical and Electronics Engineers (IEEE). In the VCS mechanism, data is transmitted in the form of a transmission frame including a physical header and data, and the data includes a SERVICE field and a Physical Layer Convergence Procedure Service Data Unit (PSDU). The PSDU is Media Access Control (MAC) layer data, including a MAC frame header, a frame body, and a Frame Check Sequence (FCS). The MAC frame header includes a duration field for indicating an expected remaining time for transmitting 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 by a source wireless device to a destination wireless device through a wireless channel, other wireless devices that use the same wireless channel with the two wireless devices may receive the transmission frame including All the contents are then determined by the FCS whether the transmission frame is a valid frame. When the transmission frame is a valid frame, a Network Allocation Vector (NAV) timer is set according to the duration field included in the transmission frame. Before the NAV timer is decremented to zero, these wireless devices cannot transmit data over the wireless channel even if they hear that the wireless channel is idle, to avoid interference with wireless devices transmitting data on the wireless channel.

In the above method, when the transmission frame is an invalid frame, the devices cannot set the NAV timer according to the duration, and the data is transmitted on the wireless channel, so that multiple wireless devices simultaneously transmit data in the same wireless channel at the same time. , reducing the reliability of virtual carrier sensing.

Summary of the invention

The embodiment of the invention discloses a virtual carrier sensing method and device for improving virtual carrier sensing reliability.

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

Receiving a transmission frame, where the transmission frame includes a service field and a duration field, where the service field includes a check field, where the check field carries a first check value, where the first check value is The second check value is obtained by being transmitted in the check field after being transmitted by using a wireless channel, where the second check value is calculated by a predetermined algorithm according to the field set when the wireless device that sends the transmission frame generates the transmission frame Obtained; wherein the field set is a partial field in a field included in the transmission frame, the field set includes the duration field; and the duration field includes a duration;

Determining, according to the first check value, whether the duration is an effective duration;

When it is determined that the duration is an effective duration, the local time NAV timer 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, the determining, according to the first check value, whether the duration is an effective duration, includes :

Calculating a third check value according to the predetermined algorithm according to the set of fields;

When the first check value matches the third check value, it is determined that the duration is an effective duration.

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

When the duration is determined to be an effective duration, updating the NAV timer of the local end by using the duration includes:

When the duration is determined to be a valid duration according to the first check value, 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, using the duration to update the local NAV timer.

With reference to the second possible implementation manner of the first aspect of the embodiments of the present disclosure, in a third possible implementation manner of the first aspect of the embodiments, the transmission frame further includes a physical header, where the physical header includes an indication Information, 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:

Generating 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, and the second check value is according to a field The set is calculated according to a predetermined algorithm, the field set is a partial field in a field included in the transmission frame, the field set includes the duration field, and the duration field includes a duration;

Transmitting the transmission frame such that the wireless device receiving the transmission frame determines whether the duration is an effective duration according to a first check value, and when determining that the duration is an effective duration, utilizing Updating the network allocation vector timer of the wireless device, 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 embodiments of the present invention, in a first possible implementation manner of the second aspect of the embodiments, the transmission frame further includes a receiving address field, where the receiving address field includes a receiving address of the transmission frame. The set of fields further includes the receive address field.

With reference to the first possible implementation manner of the second aspect of the embodiments of the present invention, in a second possible implementation manner of the second aspect of the embodiments, the transmission frame further includes a physical header, where the physical header includes an indication Information, 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, where the service field includes a check field, where the check field carries a first check value, where the first The check value is obtained after the second check value is carried in the check field and transmitted by the wireless channel, where the second check value is a field according to the wireless device that sends the transmission frame to generate the transmission frame. The set is calculated according to a predetermined algorithm; wherein the field set is a partial field in a field included in the transmission frame, the field set includes the duration field; and the duration field includes a duration;

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

And an updating unit, configured to update the NAV timer of the wireless device by using the duration when the determining unit determines that the duration is an effective duration.

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

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

The updating unit is configured to: when the duration is determined as the effective duration according to the first check value, and the receiving address is a valid receiving address, if the receiving address and the address of the wireless device are not Matching, and the duration is greater than the time of the wireless device's NAV timer, 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 embodiments of the present invention, in a third possible implementation manner of the third aspect of the embodiments, the transmission frame further includes a physical header, where the physical header includes an indication Information, 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, where:

The input device is configured to receive a transmission frame and send the data to the processor, where the transmission frame includes a service field and a duration field, where the service field includes a check field, where the check field carries a a check value, where the second check value is obtained by being transmitted in the check field after being transmitted through a wireless channel, and the second check value is a wireless sending the transmission frame The device generates the transmission frame according to a field set according to a predetermined set of algorithms; wherein the field set is a partial field in a field included in the transmission frame, and the field set includes the duration field; The time field includes the duration;

The memory stores a set of program codes, and the processor is configured to call the program code stored in the memory to perform the following operations:

The NAV timer of the wireless device is updated with the duration when the duration is determined to be an effective duration.

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

The processor is configured to calculate, according to the set of fields, a third check value according to the predetermined algorithm;

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

The manner in which the processor is used to update the NAV timer of the local end by using the duration when the duration is determined to be the effective duration is specifically:

The processor is configured to: when the duration is determined to be a valid duration according to the first check value, and the receiving address is a valid receiving address, if the receiving address does not match an address of the wireless device, and The duration is greater than the time of the wireless device's NAV timer, and the wireless device's NAV timer is updated with the duration.

With reference to the second possible implementation manner of the fourth aspect of the embodiments of the present invention, in a third possible implementation manner of the fourth aspect of the embodiments, the transmission frame further includes a physical header, where the physical header includes an indication Information, 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, where the service field includes a check field, where the check field carries a second check value, and the second The check value is calculated according to a field set according to a predetermined algorithm, the field set is a partial field in a field 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 a transmission frame generated by the generating unit, so that the target wireless device that receives the transmission frame determines, according to the first check value, whether the duration is a valid duration, and when determining the Updating the target wireless device with the duration when the duration is the effective duration A network allocation vector timer, 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 fifth aspect of the embodiments of the present invention, in a first possible implementation manner of the fifth aspect of the embodiments, the transmission frame further includes a receiving address field, where the receiving address field includes a receiving address of the transmission frame. The set of fields further includes the receive address field.

With reference to the first possible implementation manner of the fifth aspect of the embodiments of the present invention, in a second possible implementation manner of the fifth aspect of the embodiments, the transmission frame further includes a physical header, where the physical header includes an indication Information, 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, where:

The output device is configured to send the transmission frame, so that the target wireless device that receives the transmission frame determines, according to the first check value, whether the duration is a valid duration, and when determining the duration Updating the network allocation vector timer of the target wireless device by using the duration, wherein the first check value is that the second check value is carried in the check field Obtained after the wireless channel is transmitted.

With reference to the sixth aspect of the embodiments of the present invention, in a first possible implementation manner of the sixth aspect of the embodiments, the transmission frame further includes a receiving address field, where the receiving address field includes a receiving address of the transmitting frame The set of fields further includes the receive address field.

With reference to the first possible implementation manner of the sixth aspect of the embodiments of the present invention, in a second possible implementation manner of the sixth aspect of the embodiments, the transmission frame further includes a physical header, where the physical header includes an indication Information, 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 only when the received transmission frame is a valid frame. Updating the local NAV timer; when the received transmission frame is an invalid frame, the wireless device cannot set the NAV timer according to the duration, and the data is sent on the wireless channel, so that multiple times appear in the same wireless channel at the same time. The wireless device transmits data at the same time, which reduces the reliability of virtual carrier sensing. In the virtual carrier sensing method provided by the embodiment of the present invention, the duration of the received transmission frame is determined according to the first check value carried in the check field by including a check field in the service field of the transport frame. Whether it is a valid duration, whether the received transmission frame is a valid frame, that is, it is not necessary to use the FCS to judge whether the transmission frame is a valid frame for the entire frame of the transmission frame, and only needs to verify the duration included in the transmission frame. When it is determined that the duration included in the transmission frame is the effective duration, the duration of the NAV timer can be updated by using the duration, so that the local end does not send data before the time of the NAV timer is reduced to zero, avoiding the same wireless at the same time. The situation in which multiple wireless devices simultaneously transmit data occurs in the channel, thereby improving the reliability of virtual carrier sensing.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are some embodiments of the present invention. One of ordinary skill in the art can also obtain other drawings based on these drawings without paying for inventive labor.

FIG. 1 is a flowchart of a virtual carrier sensing method according to an embodiment of the present invention;

2 is a process for carrying a check value by using a scrambling code generator according to an embodiment of the present invention;

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

4 is a flowchart of a MAC frame header compression method according to an embodiment of the present invention;

FIG. 5 is a flowchart of another MAC frame header compression method according to an embodiment of the present invention;

6 is a structural diagram of a wireless device according to an embodiment of the present invention;

FIG. 7 is a structural diagram of another wireless device according to an embodiment of the present invention; FIG.

FIG. 8 is a structural diagram of still another wireless device according to an embodiment of the present invention; FIG.

FIG. 9 is a structural diagram of still another wireless device according to an embodiment of the present invention; FIG.

FIG. 10 is a structural diagram of still another wireless device according to an embodiment of the present invention; FIG.

11 is a structural diagram of still another wireless device according to an embodiment of the present invention;

FIG. 12 is a structural diagram of still another wireless device according to an embodiment of the present invention; FIG.

FIG. 13 is a structural diagram of still another wireless device according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The embodiment of the invention discloses a virtual carrier sensing method and device for improving virtual carrier sensing reliability. The details are described below separately.

Due to the unreliability of the wireless channel, the transmission of the transmission frame may be erroneous, 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 parity data to the transmission frame, that is, inputs the content of the transmission frame into a predetermined verification algorithm to obtain a transmission check value. It is then carried in the Frame Check field in the transport frame. After receiving the transmission frame, the receiving end calculates the received frame by using the same check algorithm as the receiving end, and obtains the received check value, and then compares it with the transmitted check value obtained from the received transmission frame. If the two match, it is considered that the transmission frame content is received correctly, that is, the transmission frame is a valid frame; if it does not match, it indicates that the transmission frame content is in error during transmission, or the transmission check value transmission error occurs, that is, the transmission frame is invalid. Frame, at this time, the receiving end discards the transmission frame.

Errors due to unreliable wireless channels may occur anywhere in the transmission frame. When the device receives an invalid transmission frame (that is, the frame check value matches as a mismatch), 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 Own NAV timer, but in the prior art, when an invalid transmission frame is received, the frame is discarded, and the information of the duration that is still valid in the invalid transmission frame is not utilized. Therefore, a mechanism is needed to enable the receiving end to determine whether the duration field in the transmission frame is erroneous even in the case of an overall transmission error of the received transmission frame.

On the other hand, from the implementation point of view, 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 receive itself according to the receiving address field in the frame header, it will directly discard it. The frame will not continue to receive subsequent portions of the transmission frame to save energy. In this case, the receiving device has no way to determine whether the duration field is received correctly or not. If it receives an error, use Setting a NAV timer can cause unpredictable problems. Therefore, in the case where the wireless device only receives the frame header, it is necessary to accurately determine whether the duration field is correctly received.

In summary, it is necessary to add a new check field in the frame header and the previous position in the transmission frame to verify the duration field. The method enables the receiving wireless device to determine whether the duration field is correctly received if only part of the transmission frame is received, thereby enabling the NAV timer to be correctly set and saving energy; and at the same time, even after receiving an invalid transmission frame In this case, the receiving wireless device can also individually determine whether the duration field is received correctly, thereby using it to set the NAV timer. Compared with the existing methods, the method provided by the embodiments of the present invention enables the wireless device to obtain an effective duration in more cases, thereby making the virtual carrier sensing mechanism more effective.

Please refer to FIG. 1. FIG. 1 is a flowchart of a virtual carrier sensing method according to an embodiment of the present invention. The virtual carrier sensing method shown in FIG. 1 is applicable to 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, where the service field includes a check field, the check field carries a first check value, and the first check value is carried by the second check value. After the wireless channel is transmitted in the check field, the second check value is calculated by the predetermined algorithm according to the field set when the wireless device that sends the transmission frame generates the transmission frame; wherein the field set is in the field included in the transmission frame. Part of the field, the field set includes a 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 padding (Pad). Among them, in some cases, there are no tail and padding in the data. The PSDU is MAC layer data, the PSDU includes a MAC frame header, a frame body, and an FCS, the MAC frame header includes a duration field, and the duration field includes a duration. The service field includes a check field, a scrambling code initial value (Scrambler Initialization), where the check field carries a first check value, and the first check value is a second check value carried in the check field. After the wireless channel is transmitted, the second check value is calculated by the predetermined algorithm according to the field set when the wireless device that generates the transmission frame generates the transmission frame; wherein the field set is a part of the field included in the transmission frame, the field The set includes a duration field; the duration field includes the duration. Wherein, the first check value and the second check value are Can be equal or not equal; when the verification field transmission error occurs during transmission, the two are not equal; when the verification field is transmitted correctly during transmission, the two are equal.

In this embodiment, the service field may carry the check value by using a basic method or an extended method. The basic method is as follows: the length of the service field is generally 16 bits, where 7 bits is the initial value of the scrambling code generator and cannot carry information. Therefore, the remaining 9 bits can be used to carry the check value. The 802.11ac standard has proposed to use 8 bits 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. Set check value. 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 check value length, the more likely the misjudgment is. Therefore, the extension method further increases the check value length based on the basic method, specifically: implicitly carrying the initial state value of the scrambling code generator of the transmission frame source wireless device. Check the value to increase the length of the check value.

In this embodiment, the scrambling code generator initial value and initial state are two different concepts. The former is the name of a subfield in the SERVICE field, the length is 7bits, usually takes a fixed value, for example, the current 802.11 standard takes 7bits all 0 sequence; the latter is the initial value of the 7-bit shift register in the scrambling code generator, the length It is 7 bits, usually random, but not all 0s, used to generate a scrambling sequence. In the actual transmission, the transmitting end first generates a scrambling code sequence based on the initial state value of 7 bits, and then performs exclusive-OR operation on the first 7 bits of the scrambling code sequence and the 7-bit all-zero sequence of the initial value of the scrambling code generator, and the result is used as scrambling. The subsequent data is transmitted on the wireless channel; after receiving the scrambled data, the receiving end XORs the 7-bit all-zero sequence of the initial value of the scrambling code generator to obtain the first 7 bits of the transmitting end scrambling sequence. According to the specific configuration of the scrambling code generator, the receiving end can inversely derive the initial state value used by the transmitting end to generate the scrambling code sequence by using the 7-bit scrambling code sequence, thereby generating a scrambling code sequence identical to the transmitting end, for Receiver descrambling. The initial state value of the scrambling code generator is used to carry the verification information, that is, the verification information is used to replace the random value, and the receiving end needs to inversely derive the initial value according to the received initial value and combine the specific structure of the scrambling code generator to obtain the initial of the transmitting end. The status value (check information) is therefore implicit.

For example, the scrambling code generator is a 7-bit cyclic shift register. After a 7-bit initial value, a scrambling code sequence with a period of 127 can be output. In the conventional mechanism, the transmission frame source wireless device randomly selects a non-all-zero 7-bit binary sequence as the scrambling code generator initial state value. In the extension method, 6 bits (X1 to X6) in the check value are used instead of 6 bits in the 7-bit random sequence, and the remaining 1 bit is always set to 1 (to ensure The initial state values are not all 0). After the other wireless devices receive the transmission frame, the 7-bit initial state value can be derived in reverse, and 6 bits are the contents of the check value. In the method, the initial value of the scrambling code generator implicitly carries the 6-bit check value (X1 to X6), and the 9-bit (X7-X15) directly carried by the service field, the check value may include at most 15 bits. The process is shown in Figure 2.

In this embodiment, when the source wireless device transmitting the frame transmits the transmission frame, other wireless devices that use 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:

Calculating a third check value according to a predetermined set according to a field set;

When the first check value matches the third check value, it is determined that the duration is the effective duration.

In this embodiment, after receiving the transmission frame, it is determined whether the duration is a valid duration according to the first check value, that is, calculating a third check value of the field set included in the received transmission frame, and determining the first check. Whether the value matches the third check value. Among them, the first check value will match the third check value only when the check field and the field set are transmitted correctly. The matching can be equal or has a corresponding relationship. For example, if one side is inverted and equal to the other, it can be understood that there is a correspondence between the two parties.

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

S103. When determining that the duration is the effective duration, update the local NAV timer by using the duration.

In this embodiment, when it is determined that the duration is the effective duration, that is, the first check value matches the third check value, the NAV timer of the local end is updated by using the duration, that is, the time of the NAV timer is set to the duration. Value, so that the local end does not send data before the time of the NAV timer is decremented to zero, to prevent the data sent by the local end from causing interference to the data being transmitted in the same wireless channel; When the duration is invalid, the local NAV timer will not be updated.

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

When it is determined that the duration is the effective duration, the manner of updating the local NAV timer by using the duration is specifically as follows:

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

In this embodiment, when the transmission frame includes a duration field and a reception address field, the third check value is calculated according to a predetermined set according to the field set, that is, the third check value is calculated according to a predetermined algorithm according to the duration field and the received address field. . Therefore, when the first check value matches the third check value, it can be indicated that the duration is the effective duration and the received address is a valid receive address. When the first check value does not match the third check value, it may indicate 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 the first check value, the duration, and the receiving address field, after receiving the transmission frame, first use the first check value to verify whether the duration is a valid duration, and whether the receiving address field is The effective address field, when the duration is the valid duration, and the receiving address field is a valid address field, it is determined 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 (indicating that the transmission frame is not sent to the local address) The transmission frame of the terminal further determines whether the duration is greater than the time of the network allocation vector timer of the local end. When the duration is longer than the time of the network allocation vector timer of the local end, the NAV timer of the local end is updated by using the duration; when receiving the address field If the address field is invalid, it indicates that the duration field is also an invalid field. 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 address of the local end, it indicates that the transmission frame is The transmission frame sent to the local end, continue to receive the other within the transmission frame ; When receiving a valid address field address field, a receiver address does not match the address of the local, and the duration is less than or equal to the local network allocation vector timer time duration will not use the present updated NAV timer ends. The receiving address is the address of the destination wireless device that transmits the 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 address of the local end matches the receiving address, including the following situation: when receiving When the unicast receiving address matches the local address, the local address matches the receiving address. When the receiving address is the multicast receiving address, the multicast receiving address is defined in the multicast group. If the address of the local end is included, the address of the local end matches the receiving address. When the receiving address is the broadcast receiving address, the local address matches the receiving address. In other cases, 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, where 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, first use the indication information to determine whether the transmission frame includes a check field, and when the transmission frame includes a check field. 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 determined whether the receiving address matches the address of the local end. When the receiving address does not match the address of the local end, Indicates that the transmission frame is not the transmission frame sent to the local end, and determines whether the duration is greater than the time of the network allocation vector timer of the local end. When the duration is longer than the time of the network allocation vector timer of the local end, the local end NAV timer is updated by using the duration. 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 received address field is the invalid address field, it indicates that the duration field is also an invalid field, and the duration will not be utilized. Update the local NAV timer; when the transmission frame includes a check field, receive the address word If the address 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 contents of the transmission frame; when the transmission frame includes a check field, the receiving address field is a valid address field, When the receiving address does not match the local address and the duration is less than or equal to the time of the local network allocation vector timer, the local NAV timer will not be updated with the duration.

In the existing method, the wireless device updates the local NAV timer by using the duration 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. The device transmits data on the wireless channel, so that multiple wireless devices in the same wireless channel simultaneously transmit data at the same time, which reduces the reliability of virtual carrier sensing. In the virtual carrier sensing method provided by the embodiment of the present invention, the duration of the received transmission frame is determined according to the first check value carried in the check field by including a check field in the service field of the transport frame. Whether it is a valid duration, whether the received transmission frame is a valid frame, that is, it is not necessary to use the FCS to judge whether the transmission frame is a valid frame for the entire frame of the transmission frame, and only needs to be included in the transmission frame. The time is checked. When it is determined that the duration included in the transmission frame is the effective duration, the duration can be used to update the local NAV timer so that the local end does not send data until the time of the NAV timer is reduced to zero. To avoid the situation that multiple wireless devices simultaneously transmit data in the same wireless channel at the same time, thereby improving the reliability of virtual carrier sensing.

Referring 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 applicable to 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 transmitting side, and the related steps can be understood by referring to the foregoing. 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, where 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 set according to the field set. The field set is a partial field in a field included in the transmission frame, the field set includes a duration field, and the duration field includes a duration.

For example, the scrambling code generator is a 7-bit cyclic shift register. After a 7-bit initial value, a scrambling code sequence with a period of 127 can be output. In the conventional mechanism, the transmission frame source wireless device randomly selects a non-all-zero 7-bit binary sequence as the scrambling code generator initial state value. In the extension method, 6 bits (X1 to X6) of the check value are used instead of 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 the other wireless devices receive the transmission frame, the 7-bit initial state value can be derived in reverse, and 6 bits are the contents of the check value. In the method, the initial value of the scrambling code generator implicitly carries a 6-bit check value (X1 to X6), plus 9 bits directly carried by the service field. (X7 ~ X15), the check value can contain up to 15bits, the process is shown in Figure 2.

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

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 receives the transmission frame determines whether the duration is an effective duration according to the first check value, and updates the wireless device by using the duration when determining that the duration is the effective duration. A network allocation 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 the effective duration according to the first check value may be understood by referring to related content 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, and in the process of transmitting, the wireless device corresponding to the receiving address uses the same wireless channel due to the broadcast characteristic of the wireless channel itself. The other wireless devices receive, so that the 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, the NAV timers will be updated with the duration to avoid the same time A situation in which multiple wireless devices simultaneously transmit data in the same wireless channel.

In the virtual carrier sensing method described in FIG. 3, the generated transmission frame includes a check field, and the check field carries a second check value, and the wireless device corresponding to the received address uses other wireless devices of the same wireless channel. After receiving, the first check value is used to verify whether the duration is a valid duration, where 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 the effective duration, the NAV timers will be updated with the duration to avoid the situation where multiple wireless devices simultaneously transmit data in the same wireless channel at the same time, thereby improving the reliability of virtual carrier sensing.

Referring to FIG. 4, FIG. 4 is a flowchart of a MAC frame header compression method according to an embodiment of the present invention. Figure. The MAC frame header compression method shown in FIG. 4 is applicable to 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, where the transmission frame includes a physical header, a MAC frame header, and a frame check sequence. The MAC frame header includes a type of the transmission frame, a transmission direction of the transmission frame, and an address field set, and the physical header includes a direction for indicating whether the transmission frame is Compress the indication of the transmission frame.

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

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

S402. Determine an address field in the address field set that can be removed 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, or the like.

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

In this embodiment, the data frame can be divided into a direct frame (From DS=0, To DS=0) and a downlink frame (From DS=1, To DS= according to different values of From DS and To DS in the control field. 0), the upstream frame (From DS=0, To DS=1) and the 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, and the receiving address and the sending address may be removed when the frame body When the part is a MAC Service Data Unit (MSDU), the third address is the source wireless device address or the destination wireless device address (the device address outside the current Wi-Fi network), so the third address cannot be compressed; When the frame part is an aggregated MSDU (Aggregate MSDU, A-MSDU), and the third address is a Basic Service Set Identifier (BSSID), that is, an access point address, it can be compressed. How do you know if the received transport frame body part is MSDU or A-MSDU? In fact, there is an A-MSDU indication in the Quality of Service (QoS) Control (Control) field located in the MAC frame header to indicate that the frame body part is an A-MSDU or an MSDU, and its location is after the third address. . Therefore, the presence or absence of the third address will affect the relative position of the QoS Control field in the frame, that is, according to the QoS control field position, the receiver cannot first obtain an indication of the presence of the A-MSDU through the field, and then determine whether the third address exists. . Therefore, when compressing the transmission frame, the QoS Control field is referred to the position before all the address fields, so that the receiver can first check the indication of the presence of the A-MSDU in the QoS Control field, thereby determining whether the third address is compressed. The QoS control field location shift may occur before the FCS calculation, or may occur after the FCS calculation. This embodiment is not limited, but other devices should also perform corresponding reverse operations after receiving the transmission frame. Direct Connected Frames: Includes two site addresses that are directly connected, and the addresses of the same access point associated with the two sites, all of which can be compressed.

In this embodiment, the management frame includes a receiving address, a sending address, and a third address, where the receiving address and the sending address may be compressed, and the third address may be a BSSID (an address of the access point) or a wildcarded BSSID, and the wildcard is matched. The BSSID cannot be compressed. Therefore, there are two schemes for managing the frame address field set compression: A) only receiving the address and sending address, the third address is always uncompressed; B) when the third address is the BSSID, the 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, the scheme B is a preferred scheme.

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

In this embodiment, if the transmission frame includes an aggregated MAC protocol data unit (Aggregate MAC) The protocol data unit (A-MPDU) uses the above address field removal rule for all MAC protocol data units (MPDUs) in the A-MPDU.

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

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

In this embodiment, the physical header includes a SIG field, and 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 indicates that the transmission frame is a compressed transmission frame, and when the value of the indication information is 0, it indicates that the transmission frame is an uncompressed transmission frame.

S405. Send a compressed transmission frame.

In the MAC frame header compression method shown in FIG. 4, some or all of the address fields in the MAC frame header address field are removed before the transmission frame is transmitted, so as to reduce the MAC frame header length of the transmission frame and reduce the MAC frame. The proportion of the head occupied in the transmission frame, thereby improving channel utilization.

Referring to FIG. 5, FIG. 5 is a flowchart of another MAC frame header compression method according to an embodiment of the present invention. The MAC frame header compression method shown in FIG. 5 is applicable to 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, where the transmission frame includes a physical header, a MAC frame header, and a frame check sequence. The MAC frame header includes a type of the transmission frame, a transmission direction of the transmission frame, and an address field set, where the physical header includes indication information, and the indication information is used. 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. Therefore, since the ratio of the transmission frame occupied by the MAC frame header in the short frame is larger than the ratio of the transmission frame occupied by the MAC frame header in the long frame, the short frame is short. Reduced wireless channel utilization. One way to improve the short-band wireless channel utilization is to aggregate these short frames into long frames for transmission when a wireless device has multiple short frames to transmit. However, when these short frames belong to different users, they cannot be aggregated between them. Therefore, in this embodiment, starting from the MAC frame header of the short frame, the ratio of the transmission frame occupied by the MAC frame header is reduced by compressing the address field in the MAC frame header. The indication information may also be located in the SERVICE domain. The SERVICE field is located before the MAC frame header.

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

In this embodiment, since the recovery process needs to be performed after receiving the compressed transmission frame, when the transmission frame is not When the transmission frame is compressed, no recovery processing is required. Therefore, the indication information is included in the SIG field in the physical header of the transmission frame 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 transmission frame SIG field is 0, it indicates that the transmission frame is not a compressed transmission frame. The transmission frame may be a control frame, a data frame, a management frame, or the like. The transmission direction of the transmission frame may be a downlink frame, an uplink frame, a direct connection frame, or the like.

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

In this embodiment, after receiving the transmission frame, 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 address field is determined to be moved by using the type of the transmission frame and the transmission direction of the transmission frame. Except the address.

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

Any one or more of the receiving address, the sending address, and the third address in the transmission frame may be compressed. Here, the compressed receiving address and the sending address are taken as an example to illustrate how the receiving end recovers the compressed address field. Other situations are handled in a similar manner and will not be described here.

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

A1: The address of the wireless device associated with the local end is used as the sending address of the transmission frame, and the address of the local end is used as the receiving address of the transmission frame to obtain the transmission frame including the removed address.

A2. Calculate a 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 transport frame including the removed address is used as the decompressed transmission frame.

In this embodiment, when the removed address is composed of the sending device address 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 transmission address of the transmission frame and the address of the local end is Transmitting a receiving address of the frame to obtain a transmission frame including the removed address, and then calculating a target frame check sequence of the transmission frame including the removed address by using a cyclic redundancy algorithm, and then determining the target frame check sequence and the transmission frame include Whether the frame check sequence matches, when the target frame check sequence matches the frame check sequence included in the transmission frame, it indicates that the assumption is established, and the transmission frame is sent by the associated wireless device to the present The transmission frame of the terminal, the transmission frame including the removed 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 is not established, and the transmission frame is not sent by the associated wireless device. The transmission frame of the end. When the wireless device connected to the local end is a plurality of wireless devices, the foregoing operations are performed multiple times until the matching is successful or all wireless devices connected to the local end are tried.

In this embodiment, when multiple wireless devices are associated with the local end, in order to quickly determine the identity of the transmitting end and reduce the number of trials, some auxiliary mechanisms may be employed. A basic scheme is to compress only one or more of the addresses, and the other addresses are not compressed. For example, in the uplink frame or the downlink frame, the receiving address is reserved, and the sending address is compressed; in the directly connected frame, the source station or destination is reserved. The address of the site, while compressing the address of the other site and the address of the access point. In addition, a short identifier of the sender device, such as an AID, a PAID, or the like, may be carried in the physical header or the MAC header of the transport frame while compressing the address field set.

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

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

The receiving unit 601 is 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, and the first check value is a second school The verification value is obtained after being transmitted by the wireless channel in the check field, and the second check value is calculated by the predetermined algorithm according to the field set when the wireless device that transmits the transmission frame generates the transmission frame; wherein the field set is the transmission frame a partial field in the included field, the field set includes a duration field; the duration field includes a duration;

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

The updating unit 603 is configured to update the NAV timer of the wireless device by using the duration of the transmission frame received by the receiving unit 601 when the determining unit 602 determines that the duration is the effective duration.

Specifically, the updating unit 603 is specifically configured to update the NAV timer of the wireless device by using the duration when the determining unit 602 determines that the duration is the effective duration.

As a possible implementation manner, the determining unit 602 is specifically configured to:

The updating unit 603 is specifically configured to: when the duration is determined as the effective duration according to the first check value, and the receiving address is the valid receiving address, if the receiving address does not match the address of the wireless device, and the duration is greater than the wireless device When the network allocates the time of the vector timer, the network allocation vector timer of the wireless device is updated with the duration.

In the existing method, when the receiving address is a valid address and the receiving address does not match the address of the local end, if the transmission frame is a valid frame, the NAV timer of the local end is updated by using the duration; when the received transmission frame is invalid During the frame, the wireless device cannot set the NAV timer according to the duration, and the data is sent on the wireless channel, so that multiple wireless devices simultaneously transmit data in the same wireless channel at the same time, thereby reducing the reliability of virtual carrier sensing. . In the virtual carrier sensing method provided by the embodiment of the present invention, the duration of the received transmission frame is determined according to the first check value carried in the check field by including a check field in the service field of the transport frame. Whether it is a valid duration, whether the received address included in the received transmission frame is a valid receiving address, and whether the received transmission frame is a valid frame, it is not necessary to use the FCS to determine whether the transmission frame is a valid frame for the entire frame of the transmission frame, The receiving address and duration included in the transmission frame need to be verified. 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 a valid duration. The duration of the NAV timer is updated to prevent the local end from transmitting data before the time of the NAV timer is reduced to zero, thereby preventing multiple wireless devices from transmitting data simultaneously in the same wireless channel at the same time, thereby improving Virtual carrier sensing reliability.

Please refer to FIG. 7. FIG. 7 is a structural diagram of another wireless device according to an embodiment of the present invention. The wireless device may be a mobile phone, a tablet, or the like, which is not limited in this embodiment. As shown in Figure 7, the no The line device 700 can 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, the processor 701 and the output device 704 can be connected by a bus or other means. In this embodiment, a bus connection is taken as an example. among them:

The input device 703 is configured to receive the transmission frame and send it to the processor 701. The transmission frame includes a service field and a duration field, where the service field includes a check field, and the check field carries the first check value, the first school The verification value is obtained after the second check value is carried in the check field and transmitted by the wireless channel, and the second check value is calculated by the predetermined algorithm according to the field set when the wireless device that transmits the transmission frame generates the transmission frame; The field set is a partial field in a field included in the transmission frame, the field set includes a duration field; the duration field includes a duration;

The memory 702 stores a set of program codes, and the processor 701 is configured to call the program code 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 the effective duration, the NAV timer of the wireless device is updated with the duration.

As a possible implementation, the output device 704 is configured to send a message.

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

The processor 701 is configured to calculate, according to a set of fields, a third check value according to a predetermined algorithm;

The manner in which the processor 701 is configured to update the network allocation vector timer of the wireless device by using the duration when determining that the duration is the effective duration is specifically:

The processor 701 is configured to: when the duration is determined as the effective duration according to the first check value, 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 updated with the duration of the network allocation vector timer of the wireless device.

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

The generating unit 801 is 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, and the second check value is pressed according to the field set The predetermined algorithm calculates that the field set is a partial field in a field included in the transmission frame, the field set includes a duration field, and the duration field includes a 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 the effective duration according to the first check value, and when determining that the duration is the effective duration And updating, by using a duration, a network allocation vector timer of the target wireless device, where the first check value is obtained after the second check value is carried in the check field and transmitted through the wireless channel.

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, and is received by another wireless device that uses the same wireless channel by the wireless device corresponding to the received address. The first check value is used 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, and the duration is valid. For the duration, the NAV timers will be updated with the duration to avoid the situation where multiple wireless devices simultaneously transmit data in the same wireless channel at the same time, thereby improving the reliability of virtual carrier sensing.

Please refer to FIG. 9. FIG. 9 is a structural diagram of still another wireless device according to an embodiment of the present invention. The wireless device may be a mobile phone, a tablet, or the like, which is not limited in this embodiment. As shown in FIG. 9, the wireless device 900 can 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, the processor 901 and the input device 904 can be connected by a bus or other means. In this embodiment, a bus connection is taken as an example. among them:

The memory 902 stores a set of program codes, and the processor 901 is configured to call the program code stored in the memory 902 to perform the following operations:

Generating 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, and the second check value is calculated according to a predetermined set of fields according to the field set, the field A set is a partial field in a field included in a transport frame, the set of fields includes a duration field, and the duration field includes a duration;

The output device 903 is configured to send a transmission frame, 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 uses the duration when determining that the duration is the effective duration Updating a network allocation vector timer of the target wireless device, 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, the wireless device 900 may further include an input device 904 for receiving a message.

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, and is received by another wireless device that uses the same wireless channel by the wireless device corresponding to the received address. The first check value is used 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, and the duration is valid. For the duration, the NAV timers will be updated with the duration to avoid the situation where multiple wireless devices simultaneously transmit data in the same wireless channel at the same time, thereby improving the reliability of virtual carrier sensing.

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

The construction unit 1001 is configured to construct a transmission frame, where the transmission frame includes a physical header, a MAC frame header, and a frame check sequence, where the MAC frame header includes a type of the transmission frame, a transmission direction of the transmission frame, and an address field set, and the physical header includes an indication Whether the transmission frame is an indication of a compressed transmission frame;

a determining unit 1002, configured to determine, according to a type of the transmission frame constructed by the building unit 1001 and a transmission direction of the transmission frame constructed by the building unit 1001, an address field in the address field set that can be removed;

The removing unit 1003 is configured to remove the address that can be removed determined by the address field set determining unit 1002 constructed by the building unit 1001 to obtain a compressed MAC frame header;

The obtaining unit 1004 is configured to set indication information in a 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, to obtain a compressed transmission frame;

The transmitting unit 1005 transmits the compressed transmission frame acquired by the obtaining unit 1004.

Specifically, the removing unit 1003 is configured to remove the address that can be removed determined by the address field concentration determining unit 1002 constructed by the building unit 1001 to obtain a compressed MAC frame header, and the trigger acquiring unit 1004 sets the constructing unit 1001. Transmitting the indication information in the physical header included in the frame, so that the indication information is used to indicate that the transmission frame is a compressed transmission frame, to obtain a compressed transmission frame.

In the wireless device shown in FIG. 10, some or all of the address fields in the MAC frame header address field are removed before the transmission frame is transmitted, so as to reduce the MAC frame header length of the transmission frame and reduce the MAC frame header transmission. The proportion occupied in the frame, thereby improving channel utilization.

Please refer to FIG. 11. FIG. 11 is a structural diagram of still another wireless device according to an embodiment of the present invention. The wireless device may be a mobile phone, a tablet, or the like, which is not limited in this embodiment. As shown in FIG. 11, the wireless device 1100 can 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, the processor 1101 and the input device 1104 may be connected by a bus or other means. In this embodiment, a bus connection is taken as an example. among them:

The memory 1102 stores a set of program codes, and the processor 1101 is configured to call the program code stored in the memory 1102 to perform the following operations:

Constructing a transmission frame, where the transmission frame includes a physical header, a MAC frame header, and a frame check sequence, the MAC frame header includes a type of the transmission frame, a transmission direction of the transmission frame, and an address field set, and the physical header includes a direction for indicating whether the transmission frame is a compressed transmission. Instruction information of the frame;

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

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

Setting 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, to obtain a compressed transmission frame;

The output device 1103 is configured to send a compressed transmission frame.

As a possible implementation, the input device 1104 is configured to receive a message.

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

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

The receiving unit 1201 is configured to receive a transmission frame, where the transmission frame includes a physical header, a MAC frame header, and a frame check sequence, where the MAC frame header includes a type of the transmission frame, a 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;

The determining unit 1202 is configured to determine, according to the indication information received by the receiving unit 1201, whether the transmission frame is To compress the transmission frame;

a determining unit 1203, configured to: when the determining result of the determining unit 1202 is YES, use the type of the transmission frame acquired by the receiving unit 1201 and the transmission direction of the transmission frame acquired by the receiving unit 1201 to determine the address removed in the centralized setting;

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 configured to use an address of the target wireless device associated with the wireless device as a sending address of the transmission frame, and an address of the wireless device as a receiving address of the transmission frame, to obtain a transmission frame including the removed address.

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

a determining subunit, configured to determine whether the target frame check sequence acquired by the sequence obtaining subunit matches the frame check sequence included in the transmission frame received by the receiving unit 1201, and when the determining subunit determines that the yes result is The transmission frame except the address is used as the decompressed transmission frame.

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

Referring to FIG. 13, FIG. 13 is a structural diagram of still another wireless device according to an embodiment of the present invention. The wireless device may be a mobile phone, a tablet, or the like, which is not limited in this embodiment. As shown in FIG. 13, the wireless device 1300 can 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, the processor 1301 and the output device 1304 may be connected by a bus or other means. This embodiment takes a bus connection as an example. among them:

The input device 1303 is configured to receive a transmission frame, where the transmission frame includes a physical header, a MAC frame header, and a frame check sequence, where the MAC frame header includes a type of the transmission frame, a 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 is stored in the memory 1302, and the processor 1301 is configured to call the memory 1302. The program code stored in it does the following:

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

When the transmission frame is a compressed transmission frame, the address removed in the address field set is 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 transmission frame.

As a possible implementation, the output device 1304 is configured to send 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 manner in which the processor 1301 adds the removed address to obtain the decompressed transmission frame is specifically:

The address of the target wireless device associated with the wireless device is used as the sending address of the transmission frame, and the address of the wireless device is used as the receiving address of the transmission frame to obtain a transmission frame including the removed address;

Calculating a target frame check sequence of the transmission frame including the removed address;

Determining whether the target frame check sequence matches the frame check sequence included in the transmission frame, and 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 FIG. 13, when the transmission frame is a compressed frame, part or all of the addresses in the MAC frame header address field are removed, and the length of the MAC frame header of the transmission frame is reduced, so that the MAC frame header is transmitted. The proportion occupied in the frame is reduced, thereby improving channel utilization.

In one embodiment, an embodiment of the present invention further discloses a computer storage medium storing a computer program. When the computer program in the computer storage medium is read into a computer, the computer can cause the computer to complete the disclosure of the embodiment of the present invention. All steps of the virtual carrier sensing method.

It should be noted that, for the foregoing various method embodiments, for the sake of simple description, they are all expressed as a series of action combinations, but those skilled in the art should understand that the present invention is not limited by the described action sequence. Because certain steps may be performed in other sequences or concurrently in accordance with the present invention. In addition, those skilled in the art should also understand 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.

One of ordinary skill in the art can understand that all or part of the various methods of the above embodiments can be completed by a program to instruct related hardware, and the program can be stored in a computer readable In the storage medium, the storage medium may include a flash disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

The virtual carrier sensing method and apparatus provided by the embodiments of the present invention are described in detail. The principles and implementations of the present invention are described in the following. The description of the foregoing embodiments is only for helping to understand the present invention. The method and its core idea; at the same time, 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 the specification should not be understood as Limitations of the invention.

Claims

A virtual carrier sensing method, comprising:

Receiving a transmission frame, where the transmission frame includes a service field and a duration field, where the service field includes a check field, where the check field carries a first check value, where the first check value is The second check value is obtained by being transmitted in the check field after being transmitted by using a wireless channel, where the second check value is calculated by a predetermined algorithm according to the field set when the wireless device that sends the transmission frame generates the transmission frame Obtained; wherein the field set is a partial field in a field included in the transmission frame, the field set includes the duration field; and the duration field includes a duration;

Determining, according to the first check value, whether the duration is an effective duration;

When it is determined that the duration is an effective duration, the local network allocation vector timer is updated with the duration.
The method according to claim 1, wherein the determining whether the duration is a valid duration according to the first check value comprises:

Calculating a third check value according to the predetermined algorithm according to the set of fields;

When the first check value matches the third check value, it is determined that the duration is an effective duration.
The method according to claim 1 or 2, wherein the transmission frame further comprises a receiving address field, the receiving address field comprises a receiving address of the transmission frame, and the field set further comprises the receiving address field ;

When determining that the duration is an effective duration, updating the network allocation vector timer of the local end by using the duration includes:

When the duration is determined to be a valid duration according to the first check value, 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 local network When the vector timer is allocated, the local network allocation vector timer is updated with the duration.
A method according to any of claims 1-3, wherein said transmission frame further comprises physics In the header, the physical header includes indication information, where the indication information is used to indicate that the transmission frame includes the check field.
A virtual carrier sensing method, comprising:

Generating 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, and the second check value is according to a field The set is calculated according to a predetermined algorithm, the field set is a partial field in a field included in the transmission frame, the field set includes the duration field, and the duration field includes a duration;

Transmitting the transmission frame such that the wireless device receiving the transmission frame determines whether the duration is an effective duration according to a first check value, and when determining that the duration is an effective duration, utilizing Updating the network allocation vector timer of the wireless device, wherein the first check value is obtained after the second check value is carried in the check field and transmitted through a wireless channel.
The method of claim 5 wherein said transmission frame further comprises a receive address field, said receive address field comprising a receive address of said transport frame, said set of fields further comprising said receive address field.
The method according to claim 5 or 6, wherein the transmission frame further comprises a physical header, the physical header includes indication information, and the indication information is used to indicate that the transmission frame includes the verification field.
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, where the check field carries a first check value, where the first The check value is obtained after the second check value is carried in the check field and transmitted by the wireless channel, where the second check value is a field according to the wireless device that sends the transmission frame to generate the transmission frame. The set is calculated according to a predetermined algorithm; wherein the field set is a partial field in a field included in the transmission frame, the field set includes the duration field; and the duration field includes a duration;

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

And an updating unit, configured to update, by the determining unit, the network allocation vector timer of the wireless device by using the duration when the determining unit determines that the duration is an effective duration.
The wireless device according to claim 8, wherein the determining unit is specifically configured to:

Calculating a third check value according to the predetermined algorithm according to the set of fields;

When the first check value matches the third check value, it is determined that the duration is an effective duration.
The wireless device according to claim 8 or 9, wherein said transmission frame further comprises a reception address field, said reception address field comprising a reception address of said transmission frame, said field set further comprising said reception address Field

The updating unit is configured to: when the duration is determined as the effective duration according to the first check value, and the receiving address is a valid receiving address, if the receiving address and the address of the wireless device are not When the duration is greater than the time of the network allocation vector timer of the wireless device, the network allocation vector timer of the wireless device is updated with the duration.
The wireless device according to any one of claims 8 to 10, wherein the transmission frame further comprises a physical header, the physical header includes indication information, and the indication information is used to indicate that the transmission frame includes the school Fields.
A wireless device, comprising a processor, a memory, and an input device, wherein:

The input device is configured to receive a transmission frame and send the data to the processor, where the transmission frame includes a service field and a duration field, where the service field includes a check field, where the check field carries a a check value, where the second check value is obtained by being transmitted in the check field after being transmitted through a wireless channel, and the second check value is a wireless sending the transmission frame The device generates the transmission frame according to a field set according to a predetermined set of algorithms; wherein the field set is a partial field in a field included in the transmission frame, and the field set includes the duration field; The time field includes the duration;

The memory stores a set of program codes, and the processor is configured to call the program code stored in the memory to perform the following operations:

Determining, according to the first check value, whether the duration is an effective duration;

The network allocation vector timer of the wireless device is updated with the duration when the duration is determined to be an effective duration.
The wireless device according to claim 12, wherein the manner in which the processor determines whether the duration is a valid duration according to the first check value is specifically:

The processor is configured to calculate, according to the set of fields, a third check value according to the predetermined algorithm;

When the first check value matches the third check value, it is determined that the duration is an effective duration.
The wireless device according to claim 12 or 13, wherein said transmission frame further comprises a reception address field, said reception address field comprising a reception address of said transmission frame, said field set further comprising said reception address Field

The method for the processor to update the network allocation vector timer of the wireless device by using the duration when the duration is determined to be an effective duration is specifically:

The processor is configured to: when the duration is determined to be a valid duration according to the first check value, and the receiving address is a valid receiving address, if the receiving address does not match an address of the wireless device, and The duration is greater than the time of the network allocation vector timer of the wireless device, and the network allocation vector timer of the wireless device is updated with the duration.
The wireless device according to any one of claims 12-14, wherein the transmission frame further comprises a physical header, the physical header includes indication information, and the indication information is used to indicate that the transmission frame includes the school Fields.
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, The service field includes a check field, where the check field carries a second check value, and the second check value is calculated according to a field set according to a predetermined algorithm, where the field set is the transmission frame. a partial field in a field, the set of fields including the duration field, the duration field including a duration;

a sending unit, configured to send a transmission frame generated by the generating unit, so that the target wireless device that receives the transmission frame determines, according to the first check value, whether the duration is a valid duration, and when determining the Updating the network allocation vector timer of the target wireless device with the duration when the duration is the effective duration, wherein the first check value is the second check value is carried in the check field Obtained after transmission through the wireless channel.
The wireless device of claim 16 wherein said transmission frame further comprises a receive address field, said receive address field comprising a receive address of said transport frame, said set of fields further comprising said receive address field.
The wireless device according to claim 16 or 17, wherein the transmission frame further comprises a physical header, the physical header includes indication information, and the indication information is used to indicate that the transmission frame includes the verification field .
A wireless device, comprising a processor, a memory, and an output device, wherein:

The memory stores a set of program codes, and the processor is configured to call the program code stored in the memory to perform the following operations:

Generating 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, and the second check value is according to a field The set is calculated according to a predetermined algorithm, the field set is a partial field in a field included in the transmission frame, the field set includes the duration field, and the duration field includes a duration;

The output device is configured to send the transmission frame, so that the target wireless device that receives the transmission frame determines, according to the first check value, whether the duration is a valid duration, and when determining the duration Updating the network allocation vector timer of the target wireless device with the duration, wherein the first check value is the second check value is carried in the check word Obtained in the segment after transmission over the wireless channel.
The wireless device of claim 19, wherein the transmission frame further comprises a reception address field, the reception address field comprising a reception address of the transmission frame, the field set further comprising the reception address field.
The wireless device according to claim 19 or 20, wherein the transmission frame further comprises a physical header, the physical header includes indication information, and the indication information is used to indicate that the transmission frame includes the verification field .