Device, method and product for promoting data conversion in radio network

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to the field of wireless communication between devices involved in the formation of a network, and more particularly to devices, methods, and software for facilitating data exchange in a wireless network even in the presence of hidden nodes.

【0002】

[Conventional technology]

The use of local area networks (LANs) to transfer data is increasing. Wireless LAN, also known as WLAN, is a relatively new application. These wireless LANs can provide the advantages of wired LANs without physically coupling different stations to each other. Also, there is no need to purchase transmission wires such as coaxial lines, twisted pair cables, and optical fibers to transfer data. Instead, it uses either radio frequency (RF) waves, also known as microwaves, or light waves, such as infrared (IR) light, to transfer data through the air. A network can be formed by bringing the components closer together without connecting the transmission line to the components.

【0003】

Wireless-based WLANs have some features that differ from those of wired LANs. One of these characteristics is the low amount of data that can be achieved, due to a number of factors, such as limited bandwidth. Therefore, it is desired not to waste the time window in such wireless communication.

【0004】

Moreover, many devices share the same medium, which can cause problems if simultaneous transmission is allowed. Hereinafter, these problems will be described in more detail.

【0005】

FIG. 1 is a structural diagram for showing problems in the prior art. Referring to FIG. 1, the network 110 includes a device 120 that operates as an access point (AP) 120 to the network 110.

【0006】

AP120 can establish simultaneous wireless communication between the first radio station STA1 (140) and the second radio station STA2 (150). This means that two communication links are established, namely link 145 with STA1 (140) and link 155 with STA2 (150).

【0007】

Both links 145 and 155 are in the same medium 165. It is clear that peripheral stations STA1 (140) and STA2 (150) need to be prevented from transmitting simultaneously along links 145 and 155, respectively. Simultaneous transmission within the same medium 165, if recognized, degrades the data received by the AP 120.

【0008】

Simultaneous transmission is generally prevented by forcing all devices to follow the protocol. Many of these protocols have been developed as standard 802.11 under the guidance of the IEEE.

【0009】

One protocol is for operations in the Point Coordination Function (PCF). This protocol has AP120 that establishes a communication scheme after receiving a request from competing peripheral devices STA1 (140), STA2 (150). There are requests to reserve resources such as bandwidth and memory, so these resources are also known as reservation requests.

【0010】

The AP120 then handles the conflicting booking requests and resolves them. In other words, this AP120 generates a schedule that sets when each of the peripheral devices STA1 (140), STA2 (150) must transmit. Next, AP120 notifies the peripheral devices STA1 (140) and STA2 (150) of the transmission schedule as follows.

【0011】

FIG. 2 (A) is a timing diagram of a pulse exchanging data between the devices of FIG. 1 according to a known protocol, and FIG. 2 (B) is a case where one of the devices ends transmission when the schedule is exceeded. 2 (C) is a diagram showing a modified example of FIG. 2 (B), which is more efficient than FIG. 2 (B). First, refer to FIG. 2 (A). Here is a diagram of the pulses in the medium 165. The time axis TM indicates the time of the event, the pulse shown above the time axis TM is the pulse transmitted by AP120, while the pulse below the time axis TM is by STA1 (140), STA2 (150). Will be sent. In this way, the time axis TM is the coordinates when the pulse is generated. In this way, in consideration of the overall efficiency, it is arranged so that there is no signal collision.

【0012】

AP120 first transmits a scheduling pulse 220. This pulse is also called a polling pulse. Scheduling pulse 220 contains a number of components. For example, header 222, plan 224 for exchanging data with STA1 (140) during the first hour window of period T1, station STA2 (150) between the second hour window of period T2 immediately after time T1 ends. ) And plan 226 for exchanging data, and section 228, which may include trailers depending on the protocol. Section 228 may further include plans for exchanging data with other stations and the like.

【0013】

In practice, the scheduling pulse 220 is sometimes referred to as a multi-polling frame because it contains instructions for one or more peripheral stations. Although only two peripheral devices STA1 (140) and STA2 (150) have been described, this is only an example and does not limit the invention. That is, the present invention is not limited to only two peripheral stations, and in practice this description can be extended to more peripheral stations.

【0014】

Both STA1 (140) and STA2 (150) receive the scheduling pulse 220. This notifies each station of the time window. During this time window, stations are allowed to exchange data with AP120.

【0015】

The first device STA1 (140) waits during the time interval TS. This time interval TS should be short. That is, it must be shorter than the short-frame spacing (SIFS) of the connection. In this way, other devices that want to compete with the medium 165 continue to wait without breaking continuity.

【0016】

The first device, STA1 (140), then exchanges the data shown as pulse 245 with AP120. Pulse 245 covers both the top and bottom of the time axis TM at the same time, but this does not mean that simultaneous transmission occurs. During this time, STA1 (140) and AP120 exchange data, acknowledgment pulse (ACK), etc. This exchange of data continues during the first time window. This time length T1 is determined by AP120 and is obtained from scheduling pulse 220.

【0017】

Then, after another short time interval TS, the second device STA2 (150) exchanges the data shown as pulse 255 with AP120. This exchange of data continues during the second time window. The time length T2 is determined by AP120 and is obtained from scheduling pulse 220.

【0018】

Next, referring to FIG. 2 (B), a modified example is shown here. All are the same, except that the transmission of data from STA1 (140) is shown as pulse 247. Pulse 247 lasts for time T11, which time T11 is shorter than the scheduled T1. In other words, the session with AP120's first device STA1 (140) ends prematurely (interrupted). This can happen if STA1 (140) is a phone that has not received all the data by the time it should be sent.

【0019】

In FIG. 2 (B), the second device STA2 (150) initiates pulse 255 when the second time window is scheduled. However, this leaves a pause window TQ.

【0020】

This pause window TQ is at best a waste of time. In the worse case, this time window TQ is longer than TS or SIFS. This raises the possibility that a device that wants to approach and establish a connection with the AP120 will interpret the TQ as a suitable time to submit a booking request. This breaks continuity and forces rescheduling, which is inefficient. In the worst case, a collision will occur.

【0021】

Next, a solution to this problem will be described with reference to Fig. 2 (C). This solution was proposed in a paper by Lucent and Sharewave of ATT (IEEE802.11 QoS MAC Enhancement-Joint Proposal), IEEE802.11 Reference No. 00/071, May 2000.

【0022】

Briefly, it is proposed that the second hour window be rescheduled to start shortly after the end of pulse 247. This second time window should occur after time TS or the same time. The advantage of this is that the entire session ends faster. In addition, the pause window TQ is eliminated with potential problems.

【0023】

[Problems to be Solved by the Invention]

The solution of FIG. 2 (C) has a problem referred to herein as the node problem. Again, referring to FIG. 1, there may be a physical failure 173 that makes the second device STA2 (150) unable to detect the transmission of the first device STA1 (140). In other words, device STA1 (140) is a node hidden from device STA2 (150).

【0024】

In this case, it is unknown for the second device STA2 (150) when the pulse 247 (in FIG. 2C) ends. It does not have enough information for reschedule, so it considers the full window TQ to be occupied. The system then operates as shown in Figure 2 (B), losing its benefits.

【0025】

The present invention has been made in view of the circumstances as described above, and provides devices, methods, and software capable of facilitating data exchange in a wireless network even in the presence of hidden nodes. That is the purpose.

【0026】

[Means for solving problems]

The first technical means comprises a memory and a processor attached to the memory, the processor exchanging data only with the first peripheral device during the first time window, and further said the first time. After the window, generate a schedule for exchanging data only with the second peripheral device, send at least one multipole scheduling frame that encodes the schedule, and after the scheduled first hour window starts, said Data is exchanged with the first peripheral device, data exchange with the first peripheral device is completed before the end of the first time window, then a rescheduling frame is transmitted, and then the first time It is characterized in that data is exchanged with the second peripheral device before the window is closed.

【0027】

The second technical means is characterized in that, in the first technical means, the rescheduling frame is a null frame.

【0028】

The third technical means, in the first technical means, allows the generated schedule to exchange data only with the second peripheral device during the second time window, said second. The time windows alternate with the first time window according to periodicity, and the processor is further adapted to encode data relating to the periodicity in the multipole scheduling frame.

【0029】

The fourth technical means is characterized in that, in the third technical means, the rescheduling frame is a null frame.

【0030】

Fifth technical means includes a memory and a processor attached to the memory, the period during which the processor receives at least one multi-pole scheduling frame and exchanges data from the received multi-pole scheduling frame. Decodes the schedule for the first time window and the next second time window, receives the rescheduling frame during the first time window, responds to the rescheduling frame, and responds to the second time window. Is rescheduled, and then data is exchanged during the rescheduled second time window before the first time window ends.

【0031】

A sixth technical means is characterized in that, in the fifth technical means, the second time window is rescheduled to start immediately after the rescheduling frame.

【0032】

The seventh technical means is characterized in that, in the fifth technical means, the rescheduling frame is a null frame.

【0033】

Eighth technical means, in the fifth technical means, the processor decodes periodic data relating to the alternating swapping of the first time window and the second time window from the received multipole scheduling frame. It is characterized by being like this.

【0034】

A ninth technical means is characterized in that, in the eighth technical means, the second time window is rescheduled to start immediately after the rescheduling frame.

【0035】

The tenth technical means is characterized in that, in the eighth technical means, the rescheduling frame is a null frame.

【0036】

The eleventh technical means includes a storage medium in which an instruction is stored, and when the instruction is executed by at least one device, data is exchanged only with the first peripheral device during the first time window, and further, the first. After the window of, a schedule for exchanging data only with the second peripheral device was generated, at least one multipole scheduling frame encoding the schedule was transmitted, and the scheduled first hour window was started. Later, the data is exchanged with the first peripheral device, the exchange of data with the first peripheral device is completed before the end of the first time window, then a rescheduling frame is transmitted, and then the first peripheral device is transmitted. The feature is that the result of exchanging data with the second peripheral device can be obtained before the one-hour window ends.

【0037】

The twelfth technical means is characterized in that, in the eleventh technical means, the rescheduling frame is a null frame.

【0038】

The thirteenth technical means, in the eleventh technical means, allows the generated schedule to exchange data only with the second peripheral device during the second time window, said second. The time window alternates with the first time window according to the periodicity, and the instruction is characterized in that the result of encoding the data relating to the periodicity in the multi-pole scheduling frame is obtained.

【0039】

The fourteenth technical means is characterized in that, in the thirteenth technical means, the rescheduling frame is a null frame.

【0040】

A fifteenth technical means includes a storage medium that stores an instruction, and when at least one device executes the instruction, it receives at least one multi-pole scheduling frame and exchanges data from the received multi-pole scheduling frame. Decode the schedule for the first time window and the next second time window, receive the rescheduling frame during the first time window, respond to the rescheduling frame, and say the second. It is characterized in that the time window is rescheduled and then the result of exchanging data during the rescheduled second time window is obtained before the end of the first time window.

【0041】

The sixteenth technical means is characterized in that, in the fifteenth technical means, the second time window is rescheduled to start immediately after the rescheduling frame.

【0042】

The seventeenth technical means is characterized in that, in the fifteenth technical means, the rescheduling frame is a null frame.

【0043】

In the fifteenth technical means, the eighteenth technical means further decodes the periodic data regarding the alternating replacement of the first time window and the second time window from the received multi-pole scheduling frame by the instruction. The feature is that the result is obtained.

【0044】

A nineteenth technical means is characterized in that, in the eighteenth technical means, the second time window is rescheduled to start immediately after the rescheduling frame.

【0045】

The twentieth technical means is characterized in that, in the eighteenth technical means, the rescheduling frame is a null frame.

【0046】

The 21st technical means generates a schedule for exchanging data only with the first peripheral device during the first time window and further exchanging data only with the second peripheral device after the first time window. Then, at least one multi-pole scheduling frame encoding the schedule is transmitted, data is exchanged with the first peripheral device after the scheduled first time window has started, and before the end of the first time window. To complete the exchange of data with the first peripheral device, then send a rescheduling frame, and then exchange data with the second peripheral device before the end of the first time window. It is characterized by including.

【0047】

The 22nd technical means is characterized in that, in the 21st technical means, the rescheduling frame is a null frame.

【0048】

The 23rd technical means, in the 21st technical means, allows the generated schedule to exchange data only with the second peripheral device during the second time window, said second. The time window alternates with the first time window according to the periodicity, further comprising encoding data relating to the periodicity in the multipole scheduling frame.

【0049】

The 24th technical means is characterized in that, in the 23rd technical means, the rescheduling frame is a null frame.

【0050】

The 25th technical means receives at least one multi-pole scheduling frame, and from the received multi-pole scheduling frame, for a first time window and a next second time window, which is a period for exchanging data. Decode the schedule, receive the rescheduling frame during the first hour window, respond to the rescheduling frame, reschedul the second hour window, and then before the first hour window ends. , The feature comprises exchanging data during the rescheduled second time window.

【0051】

The 26th technical means is characterized in that, in the 25th technical means, the second time window is rescheduled to start immediately after the rescheduling frame.

【0052】

The 27th technical means is characterized in that, in the 25th technical means, the rescheduling frame is a null frame.

【0053】

The 28th technical means further comprises decoding in the 25th technical means the periodic data relating to the alternating swapping of the first time window and the second time window from the received multipole scheduling frame. It is characterized by that.

【0054】

The 29th technical means is characterized in that, in the 28th technical means, the second time window is rescheduled to start immediately after the rescheduling frame.

【0055】

The thirtieth technical means is characterized in that, in the 28th technical means, the rescheduling frame is a null frame.

【0056】

BEST MODE FOR CARRYING OUT THE INVENTION

In general, the present invention provides devices, products (software) and methods for rescheduling multi-party sessions at the early termination (interruption) of one session, even in the presence of hidden nodes. is there. The present invention teaches that the access point sends a rescheduling frame when the data exchange with the hidden node ends before the schedule. The second window is rescheduled based on the detection of the rescheduling frame.

【0057】

Since the rescheduling frames are sent from the access point, the rescheduling frames are detected by all peripheral devices, whether or not the peripheral devices are hidden from each other. In this way, no time is wasted and no pause window is observed. The present invention will become clearer by referring to the accompanying drawings and reading the following detailed description.

【0058】

As already mentioned, the present invention provides devices, software and methods for facilitating data exchange in wireless networks, even in the presence of hidden nodes. Hereinafter, the present invention will be described in more detail.

【0059】

FIG. 3 is a block diagram of an access point AP3 manufactured according to an embodiment of the present invention and two peripheral stations STA3 and STA4 manufactured according to an embodiment of the present invention. The access point device AP3 (320) manufactured according to the embodiment of the present invention will be described in more detail with reference to FIG. This device can be standalone or any access point device to the network (not shown in Figure 3).

【0060】

Device AP3 (320) has a processor 321 which can be implemented as a digital signal processor (DSP), central processing unit (CPU) or any other equivalent method known in the art. AP3 (320) also includes memory 322, on which program 324 can reside. The function of processor 321 can be controlled by program 324, as will be apparent from the following.

【0061】

Further, with reference to FIG. 3, the peripheral device STA3 (340) manufactured according to an embodiment of the present invention will be described in more detail. This device STA3 (340) may be any peripheral device capable of establishing a wireless communication connection 345 with AP320.

【0062】

Device STA3 (340) has processor 341, which can be implemented as a digital signal processor (DSP), central processing unit (CPU) or any other equivalent method known in the art. Device STA3 (340) also includes memory 342, on which program 344 can reside. The function of processor 341 can be controlled by program 344, as will be apparent from the following.

【0063】

The peripheral device STA4 (350) manufactured according to an embodiment of the present invention will be described in more detail with reference to FIG. The device STA4 (350) may be any peripheral device capable of establishing a wireless communication connection 355 with the AP320.

【0064】

Device STA4 (350) has processor 351 which can be implemented as a digital signal processor (DSP), central processing unit (CPU) or any other equivalent method known in the art. The device STA4 (350) also includes a memory 352, on which the program 354 can reside. The function of processor 351 can be controlled by program 354, as will be apparent from the following.

【0065】

FIG. 4 is a timing diagram of pulses for exchanging data between the devices of FIG. 3 according to an embodiment of the present invention. A timing chart for the device in Figure 3 is shown. AP3 (320) transmits (transmits) scheduler pulse 405, also known as multi-polling pulse, multi-pole frame, etc. This pulse 405 is received by both peripheral devices STA3 (340) and STA4 (350), which decode the first scheduled time window of period T3 and the second scheduled time window of period T4. The second hour window must occur after the first hour window ends. Device STA3 (340) must exchange data only during the first hour window, while device STA4 (350) must wait. Second, device STA4 (350) must exchange data only during the second hour window, while device STA3 (340) must wait.

【0066】

Device STA3 (340) exchanges signal 444 with AP320. This exchange continues during T31, which is shorter than the allotted period T3. This shortfall is due to a number of reasons, such as data not reaching device STA3 (340) in time for retransmission.

【0067】

When an earlier termination (interruption) is detected, device AP3 (320) sends a rescheduling pulse R. This rescheduling pulse R is preferably transmitted within the time TS, eg SIFS.

【0068】

The rescheduling pulse R needs to be extremely short, such as a null frame. The advantage of this is that all these peripheral devices STA3 (340), STA4 (350) can receive this pulse even if the peripheral devices are hidden from each other.

【0069】

As a promise, the rescheduling frame shall signal the rescheduling of the time window. In particular, the first time window ends at time T31 and the second time window does not occur during time T4 on the time axis TM, but must occur during the rescheduling time RT4. Therefore, it can be understood that the second time window is moved up. This second hour window does not leave any pauses, so it does not interfere with the flow set by the initial schedule of signal exchange.

【0070】

It is advantageous for the rescheduled second time window to start immediately after the rescheduling pulse. In other words, RT4 starts at time TS after the rescheduling pulse R.

【0071】

During the rescheduled second time window, the second peripheral device STA4 (350) exchanges pulse 454 with AP320. It should be noted that this exchange takes place during the first hour window of the original schedule.

【0072】

FIG. 5 (A) is a timing diagram in which the first schedule of the pulses for exchanging data between the devices of FIG. 3 is determined according to another embodiment of the present invention, and FIG. 5 (B) is the result of the present invention. It is an actual timing diagram of FIG. 5 (A) obtained. Next, an extended embodiment of the present invention will be described with reference to FIGS. 5 (A) and 5 (B). It can be seen that the scales in Figures 5 (A) and 5 (B) are larger than the scales in Figure 4.

【0073】

In FIG. 5 (A), the multi-polling pulse 505 is transmitted. The pulse 505 can be a schedule frame CF that includes periodic information that can be understood later.

【0074】

Pulse 505 is received by STA3 (340) and STA4 (350) and decoded as follows: STA3 (340) has the opportunity to exchange data during windows 541,543,545 with periods T1A, T1B, T1C, respectively. STA4 (350) has the opportunity to exchange data between windows 551, 553, 555 with periods T2A, T2B, T2C respectively. Prior to actual realization, the initially scheduled time window 541,543,545,551,553,555 is indicated by the dashed line. These periods are also decoded from pulse 505.

【0075】

FIG. 5 (B) is an actual timing diagram of FIG. 5 (A) obtained as a result of the present invention. The effect of the present invention has been shown as rescheduling. In the preferred embodiment, when the exchange is stopped due to insufficient schedule time, rescheduling is performed by uniformly advancing all schedules.

【0076】

More specifically, the scheduled time windows 541,543,545 are realized as rescheduled time windows 542,544,546 on the time axis TM, respectively. The rescheduled window 542 has a shorter duration than the rescheduled corresponding window 541. Therefore, window 542 is followed by reschedule pulse R1. The duration of reschedule windows 544,546 is equal to the corresponding scheduled windows 543,545, except that these windows occur faster than the rescheduled windows.

【0077】

Further, the scheduled time windows 551,553,555 are realized as rescheduled time windows 552,554,556 on the time axis TM, respectively. The period of rescheduled window 554 is shorter than that of the corresponding scheduled window 553. Therefore, window 554 is followed by reschedule pulse R2. The duration of the rescheduled windows 552,556 is equal to the corresponding scheduled windows, except that these windows occur faster than the rescheduled windows.

【0078】

It can be understood that rescheduling may occur after a session with either the first device or the second device. The indications presented herein as first and second are interchangeable.

【0079】

In Fig. 5 (B), we can see the combined effect of the rescheduling pulses R1 and R2. The final pulse 556 ends at the period 580 before the schedule.

【0080】

It is clear that the present invention can be realized by one or more devices including logic circuits. Further, the present invention can also be realized by a device including a microcontroller or a dedicated processor system which can include a microprocessor.

【0081】

The present invention also provides methods as described below. Further, the present invention provides a device for carrying out or assisting the method of the present invention. The device may be specially manufactured for a required purpose, or may include a general purpose computer selectively escorted or reconstructed by a computer program stored in the computer. The methods and algorithms described herein are not necessarily inherently relevant to a particular computer or other device. Various general purpose devices can be used with the program, in particular according to the gist of this specification, and it may be more convenient to manufacture more specialized devices to perform the steps of the required method. .. The structures required for these various devices will be clear from the following description.

【0082】

An effective device or product (article) for performing an operation according to the present invention includes a general-purpose digital computer or other similar device. In either case, the difference between how a computer is operated and how it is calculated should be kept in mind. The present invention also relates to steps of methods for operating a computer and steps of methods for processing electrical or other physical signals to generate other desired physical signals.

【0083】

The present invention also provides a program and a method of operating the program. This program can be most advantageously realized as a program for computing devices such as general purpose computers, special purpose computers, microprocessors and the like.

【0084】

The present invention provides a storage medium having a program of the present invention stored inside. This storage medium is a computer-readable medium, such as a memory, which is read by the arithmetic unit.

【0085】

A program is usually defined as a series of steps that give the desired result. These steps, also known as instructions, are steps that require the physical manipulation of physical quantities. Usually, these quantities can take the form of electrical or magnetic signals that can be stored, transferred, combined, compared, and manipulated or processed in other ways, but not necessarily in such form. May be good. When storing these signals, they can be stored in any computer-readable medium. It may be convenient to refer to these signals as bits, data bits, samples, values, elements, symbols, characters, signals, images, terms, numbers or the like, mainly for common reasons. However, it should be borne in mind that all of these similar terms are related to suitable physical quantities and these terms are merely expedient markers applied to these physical quantities.

【0086】

This detailed description is presented primarily as a computer-readable medium, such as a flow chart, display image, algorithm and symbol display of the operation of data bits in memory. Such descriptions and indications are convenient markers of the type used by those skilled in the art of programming and / or data processing technology to effectively convey the gist of their work to other skilled in the art. Those skilled in the art of programming techniques could use this description to easily generate specific instructions for implementing the programs according to the invention. However, for the sake of brevity, the present specification does not repeat the flowchart used to describe the method of the invention in order to describe the software according to the invention.

【0087】

For convenience only, it is often preferred to implement and describe the program as a variety of interconnected separate software modules or functions, also known as software in their entirety. However, although this is not necessary, there may be cases where the modules are evenly grouped together to form a single program with unclear boundaries. In any case, the software modules or functions of the present invention can be realized by themselves or in combination with others. I mentioned that the program can be stored on a computer-readable medium, but it should be clear to those skilled in the art that this medium does not have to be a single memory or a single machine. .. Various parts, modules or functions of the program may reside in separate memory or even in separate machines. Separate machines can be connected directly or over a network, such as a local area network (LAN) or global network, such as the Internet.

【0088】

In this case, the method of the invention is realized by the operation of the machine. In other words, examples of the programs of the invention are designed to implement the methods of the invention described herein. These examples may optionally be implemented with one or more operators who implement some, but not all, of the program. With respect to the above, the users do not have to talk to each other, each user only needs to have a machine to store a part of the program. In contrast, some of these machines may operate automatically with no users and / or with users separate from each other.

【0089】

Hereinafter, the method of the present invention will be described. Next, with reference to FIG. 6, a flowchart 600 for showing a method according to an embodiment of the present invention is shown. The method of Flowchart 600 can be implemented by the device of the access point.

【0090】

According to Box 610, a schedule is generated for the first time window to have a data exchange session with the first peripheral device and the second time window to have a session for data exchange with the second peripheral device. The window. This schedule can include a period information Ru.

【0091】

According to the next box 620, at least one multi-pole scheduling frame encoding this schedule is transmitted, which also encodes arbitrary periodic information.

【0092】

According to the next box 630, data is exchanged with the first peripheral device after the scheduled first hour window has started.

【0093】

According to the next box 640, the exchange of data with the first peripheral device is completed before the end of the first hour window.

【0094】

According to the next box 650, a rescheduling frame is sent. This frame is preferably a null frame in which it occupies the minimum amount of time.

【0095】

According to the next box 660 of the option, the second hour window is rescheduled. In a preferred embodiment, this second time window is rescheduled to start immediately after the rescheduling frame. This ensures maximum time savings without incurring long pauses.

【0096】

According to the next box 670, data is exchanged with the second peripheral device during the rescheduled second time window. This data exchange starts before the end of the first hour window.

【0097】

Next, FIG. 7 shows a flowchart 700 to show a method according to another embodiment of the present invention. The method of this flowchart 700 can be carried out by a peripheral station in a wireless communication system.

【0098】

According to Box 710, at least one multipole scheduling frame is received.

【0099】

According to the next box 720, the schedule is decoded from the received multipole scheduling frame. This schedule is for the first time window and the next second time window, during which data is exchanged.

【0100】

According to the next optional box 730, periodic data is decoded from the received multipole scheduling frame. This periodic data is data related to alternating the first time window and the second time window.

【0101】

According to the next box 740, the rescheduling frame is received during the first time frame. This frame can be a null frame as a promise.

【0102】

The next option, Box 750, reschedules the second time window in response to the rescheduling frame. It is preferable to reschedule this time window so that it starts immediately, waiting only for SIFS.

【0103】

According to the next optional box 760, data is exchanged during the second hour window, which was rescheduled before the first hour window ended.

【0104】

One of ordinary skill in the art will be able to carry out the present invention by considering the description given herein as a whole. Numerous details have been provided to further complete the understanding of the present invention. In other situations, well-known features are not described in detail so as not to unnecessarily obscure the invention.

【0105】

Although the present invention has been disclosed as a preferred embodiment above, the particular examples disclosed and described herein should not be considered limiting. If one of ordinary skill in the art examines this description, it should be readily apparent that the present invention can be modified in various ways. The inventor believes that the gist of the invention includes all combinations and quasi-combinations of the various elements, features, functions and / or properties disclosed herein.

【0106】

The claims describe certain combinations and quasi-combinations that are considered novel and inventive, as well as features, functions, elements and / or characteristics of this specification and related specifications. And another claim relating to the quasi-combination can be shown.

【0107】

[Effect of the invention]

According to the present invention, when an interruption is detected in a wireless communication session, the access point transmits a rescheduling frame R to advance the time of all sessions, thereby leaving no pause at the end. Saves time. Further, the present invention solves the problem of hidden nodes.

[Simple explanation of drawings]

[Figure 1]

It is a figure of the structure for showing the problem in the prior art.

[Figure 2]

2 is a diagram for explaining data exchange between devices according to the prior art, FIG. 2 (A) is a timing diagram of a pulse for exchanging data between devices in FIG. 1 according to a known protocol, and FIG. 2 (B) is a diagram. FIG. 2 (C), which shows a modified example of FIG. 1 when one of the devices ends transmission when the schedule is exceeded, is more efficient than FIG. 2 (B). It is a figure which shows the modification of B).

[Fig. 3]

FIG. 5 is a block diagram of an access point AP3 manufactured according to an embodiment of the present invention and two peripheral stations STA3 and STA4 manufactured according to an embodiment of the present invention.

[Fig. 4]

FIG. 5 is a timing diagram of a pulse for exchanging data between the devices of FIG. 3 according to an embodiment of the present invention.

[Fig. 5]

In a timing diagram for explaining another embodiment of the present invention, FIG. 5 (A) is a timing diagram in which the first schedule of pulses for exchanging data between the devices of FIG. 3 is determined, FIG. 5 (B). Is the actual timing diagram of FIG. 5 (A) obtained as a result of the present invention.

[Fig. 6]

It is a flowchart which shows the operation method of the access point which concerns on one Example of this invention.

[Fig. 7]

It is a flowchart which shows the operation method of the station which concerns on one Example of this invention.

[Explanation of symbols]

320 ... access point, 321 ... CPU, 322 ... memory, 324 ... program, 340 ... peripheral station, 341 ... CPU, 342 ... memory, 344 ... program, 350 ... peripheral stations, 351 ... CPU, 352 ... memory, 354 ... programs.