JP2004112556A - Radio communication system, radio communication device and radio communication method, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of performing access control while sharing a channel between radio network groups. <P>SOLUTION: A base station uses a first assigned frequency channel for a radio zone to transmit notification information to a first terminal station and uses a second assigned frequency channel to transmit notification information to a second terminal station. The first and second terminal station performs an arithmetic operation for waiting time processing associated with communication start based upon the notification information from the base station. Each terminal station initiates a communication request at a relative position on the same communication block as a relative position that a time point of generation of the communication request within all blocks has all over the block, such that temporal fluctuation of a collision probability is averaged. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wireless communication system, a wireless communication apparatus, a wireless communication method, and a computer program for mutually communicating between a plurality of wireless stations, and in particular, to each terminal station by a channel sharing method for sharing the same frequency channel. TECHNICAL FIELD The present invention relates to a wireless communication system, a wireless communication device, a wireless communication method, and a computer program for performing access control of a computer.
[0002]
More specifically, the present invention relates to a wireless communication system, a wireless communication device, and a wireless communication system that perform access control by time sharing between wireless networks or wireless groups in a wireless network environment in which a plurality of wireless networks or wireless groups coexist by time sharing. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication method and a computer program, and more particularly to a wireless communication system, a wireless communication apparatus, and a wireless communication method for suppressing a temporal change in a collision probability that causes a reduction in transmission speed in each wireless network or wireless group. , As well as computer programs.
[0003]
[Prior art]
As computers become more sophisticated, a plurality of computers are connected to form a LAN (Local Area Network) to share information such as files and data, and to share peripheral devices such as printers, 2. Description of the Related Art Information exchange such as mail and data transfer is actively performed.
[0004]
In a conventional LAN, computers are connected in a wired manner using an optical fiber, a coaxial cable, or a twisted pair cable. However, such a wired LAN requires construction for connection, making it difficult to easily construct the LAN and complicating the cable. Further, even after the LAN is constructed, the moving range of the device is limited by the cable length, which is inconvenient. Therefore, a wireless LAN has been attracting attention as a system for relieving a user from wiring of a conventional wired LAN.
[0005]
A wireless local area network (LAN) is constructed by externally connecting a wireless communication device to an information terminal such as a personal computer and connecting a plurality of personal computers to a network. According to the wireless LAN, most of the wired cable can be omitted in a work space such as an office, so that a terminal such as a personal computer (PC) can be relatively easily moved.
[0006]
In recent years, the demand for wireless LAN systems has been remarkably increased with the increase in speed and price. Particularly, recently, introduction of a personal area network (PAN) has been studied in order to establish a small-scale wireless network and perform information communication between a plurality of electronic devices existing around a person. For example, a wireless LAN system based on IEEE 802.11 has already been put to practical use.
[0007]
IEEE 802.11 defines a wireless network composed of a base station and a plurality of terminal stations in one space. That is, any one of the wireless communication devices operates as a base station of the network, and a network is formed within a communicable range. Other wireless communication devices participate in the network by performing a network operation based on a beacon signal received from the base station.
[0008]
[Problems to be solved by the invention]
In a wireless network including a base station and a plurality of terminal stations, the base station performs communication using a frequency channel allocated in a corresponding wireless zone (including a sector cell). Since a plurality of terminal stations exist in one cell and communicate with one base station at the same time, access control is required.
[0009]
For access control in a wireless network, FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access), and CDMA (Code Division Multiple Access) such as Code Division Multiple Access are available. And a channel sharing method such as ALOHA or CSMA (Carrier Sense Multiple Access).
[0010]
In packet communication or the like in which communication requests are random and highly bursty, a channel sharing scheme in which a plurality of terminal stations share the same frequency channel is often used.
[0011]
In this channel sharing scheme, since communication requests from terminal stations are made at random, signals from a plurality of terminal stations are likely to collide (that is, transmit in the same time zone). Since this collision degrades the service quality of communication, various methods have been proposed to avoid it. One of them is a CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) system.
[0012]
In a wireless LAN adopting the CSMA / CA method, collision avoidance (reduction of collision probability) is performed as follows. That is, the terminal station (base station) that has generated a communication request observes the presence or absence of a carrier (signal) on the channel, and starts communication if the channel is free for a longer time (DIFS) than the specified time. If the channel is not free, a random backoff (waiting time) is provided, and communication is started after DIFS elapses after the channel becomes free and further backoff has elapsed. However, during standby, the degree of vacancy of the carrier is checked, and the backoff is reduced only when the channel is vacant. Here, the backoff is determined based on the uniform distribution. The maximum possible value of backoff is doubled each time transmission fails.
[0013]
FIG. 8 shows a configuration (a conventional example) of a wireless network including a base station and a plurality of terminal stations. In the figure, reference numeral 1 is a base station, and reference numerals 21 to 26 are terminal stations operating under the control of the base station 1. It is assumed that the base station 1 knows the terminal stations registered in the service area based on the requests from the terminal stations 21 to 26.
[0014]
FIG. 9 shows an example of a processing operation of a communication request in each terminal station in the wireless network shown in FIG. In the figure, the carrier sense represents the carrier sense result recognized by each terminal station for convenience.
[0015]
In the example shown in the figure, the mobile station 21 has generated a communication request during the carrier sense busy. In this case, the DIFS measurement is started after the idle detection, and after the measurement, the communication is started after further waiting for the backoff.
[0016]
Further, the mobile station 22 generates a communication request in the Idle section, and becomes the carrier sense busy during the DIFS measurement. In this case as well, the DIFS measurement is started again after the idle detection, and after the measurement, the communication is started again after the backoff has elapsed.
[0017]
In addition, the mobile station 23 has started a communication as it is because a communication request is generated in the Idle section and the carrier sense is idle during the DIFS measurement.
[0018]
In this CSMA / CA system, as a precondition for reducing the probability of collision using backoff, the occurrence of communication requests is uniformly distributed, and the number of communication requests generated within a standby time is not extremely large. Is required. In other words, the standby time is not extremely long with respect to the communication request generation interval.
[0019]
By the way, when an information device such as a personal computer (PC) has become widespread and a large number of devices are mixed in an office and a communication environment in which each device is connected by a wireless network is considered, two or more communication environments are considered. Wireless networks may be crowded in a narrow working environment, and a situation may occur in which multiple wireless networks coexist on the same channel.
[0020]
In such a case, for example, a network coexistence method in which one transmission frame is shared between networks in a time-division manner or one base station operates in a time-division manner for a plurality of wireless groups can be considered.
[0021]
In the former case, terminals in each network are in a standby state in a time region allocated to another network, and therefore, when they enter the time region allocated to themselves, there is a possibility that a communication request may be generated at once. Also, in the latter case, the terminals in each wireless group are in a standby state in the time region allocated to the other group, so that when entering the time region allocated to the own group, there is a possibility that a simultaneous communication request may occur. is there.
[0022]
That is, even if the generation of a communication request is uniform in each wireless network or each wireless group, the collision probability that causes a decrease in transmission speed may change over time. There arises a problem that the standby time becomes extremely long with respect to the occurrence interval.
[0023]
FIG. 10 shows a configuration (conventional example) of a wireless network in which one base station operates in a time-division manner for a plurality of wireless groups.
[0024]
In the figure, reference numeral 1 denotes a base station that operates a plurality of wireless groups A to C. The terminals 21 to 22 belong to the group A, the terminals 23 to 25 belong to the group B, and the terminal 26 belongs to the group C, and operate. Further, it is assumed that the base station 1 grasps the terminal stations registered in the service area in response to a request from each terminal station, and also grasps a group of the terminal stations.
[0025]
FIG. 11 shows an example of a processing operation of a communication request in each terminal station in the wireless network shown in FIG. In the figure, the carrier sense represents the carrier sense result recognized by each terminal station for convenience.
[0026]
In the figure, the group division represents a standby section / communication section for group B. It is assumed that the mobile station B-1, the mobile station B-2, and the mobile station B-3 have already grasped the time point of this sectioning based on the broadcast signal received immediately before.
[0027]
As shown in the figure, the mobile station B-1, the mobile station B-2, and the mobile station B-3 all have issued a communication request during the standby period. For this reason, communication-related processing is made to wait until a communication section is reached.
[0028]
In such a case, each mobile station starts measuring the DIFS section at the same time as the start of the communication section, and then takes the first backoff value with a random number and starts measuring the backoff section. In the illustrated example, the mobile station B-1 or the mobile station B-2 starts communication when the carrier sense is Idle until the backoff measurement ends.
[0029]
Further, when the carrier sense becomes busy during the backoff measurement, the mobile station B-3 suspends the backoff measurement, and then holds the state until the carrier sense idle occurs.
[0030]
At this time, the communication between the mobile station B-1 and the mobile station B-2 starts at the same time, and a collision occurs. This is because the range in which the random number of the first backoff value can be taken is narrow. In other words, the collision probability causing a decrease in the transmission speed changes with time, and the collision occurs at a higher probability than the average value of the entire communication.
[0031]
As described above, when the standby time becomes extremely long, the communication requests generated during the standby time start communication after DIFS elapses after the channel is vacant, and further after backoff elapses, and carrier sense is performed with each other. However, the number of communication starts simultaneously occurring at the same time increases, and as a result, the communication collides as described above.
[0032]
In such a case, the collision probability is higher than the collision probability that occurs when not affected by the waiting time. This temporal variation in the collision probability results in a reduction in the average transmission rate.
[0033]
The present invention has been made in view of the above-described technical problems, and has a main object in a wireless network environment in which a plurality of wireless networks or wireless groups coexist, by time division between wireless networks or wireless groups. An object of the present invention is to provide an excellent wireless communication system, a wireless communication device, a wireless communication method, and a computer program that can appropriately perform access control by channel sharing.
[0034]
A further object of the present invention is that, in each wireless network or wireless group, a temporal fluctuation of a collision probability that causes a decrease in transmission speed is suppressed, and a standby time becomes extremely long with respect to a communication request generation interval. An object of the present invention is to provide an excellent wireless communication system, wireless communication device, wireless communication method, and computer program that can solve the problem.
[0035]
Means and Action for Solving the Problems
The present invention has been made in view of the above problems, and a first aspect thereof is a wireless communication system in which a plurality of wireless network groups coexist,
Access control is performed by channel sharing between the wireless network groups by time sharing, and a communication section of one wireless network group becomes a standby section of another wireless network group,
Each terminal station in the wireless network group starts a communication request at the same relative position on the communication section as when the communication request occurred in the entire section,
A wireless communication system characterized by the above.
[0036]
However, the term “system” as used herein refers to a logical collection of a plurality of devices (or functional modules that realize specific functions), and each device or functional module is in a single housing. It does not matter in particular.
[0037]
In the wireless communication system according to the first aspect of the present invention, the base station transmits broadcast information to the first terminal station using the first assigned frequency channel of the wireless zone, Broadcast information is transmitted to the second terminal station using the second assigned frequency channel of the wireless zone. Then, the first mobile station and the second mobile station calculate a waiting time process related to the start of communication based on the broadcast information from the base station.
[0038]
Each terminal station issues a communication request at an arbitrary timing in all sections including the communication section allocated to its own network group and other standby sections, but when a communication request occurs in the standby section, The activation of the communication request is waited until the communication section arrives.
[0039]
According to the first aspect of the present invention, a terminal station in a wireless network issues a communication request at a relative position on the same communication section as a relative position on the entire section when a communication request occurs in the entire section. It is designed to start.
[0040]
Therefore, a process for averaging the temporal variation of the collision probability that causes a decrease in the transmission speed is performed, and as a result, the problem that the standby time becomes extremely long with respect to the interval between occurrences of communication requests is solved. can do.
[0041]
A second aspect of the present invention is a wireless communication device or a wireless communication method operating in a wireless communication environment in which a plurality of wireless network groups coexist,
Means or steps for receiving broadcast information describing frequency channel assignment from a base station operating a radio network group;
Calculating means or steps for determining a transmission delay for a communication request based on broadcast information from the base station;
A communication request unit or a step of starting a communication request by applying a transmission delay corresponding to the delay amount obtained by the arithmetic unit or the step;
A wireless communication device or a wireless communication method.
[0042]
Access control is performed by channel sharing between the wireless network groups by time sharing, and a communication section of a certain wireless network group is a standby section of another wireless network group. According to the wireless communication device or the wireless communication method according to the second aspect of the present invention, the calculating means or the step may include: The position is obtained as a transmission delay of a communication request.
[0043]
If this is concretely expressed as a mathematical expression, a is the waiting time, b is the time until the next notification signal, c is the time elapsed until the communication request is generated, and d is the time for processing the communication request. And d = a + (ba) × c /
Calculate the communication request activation time point by the following equation.
[0044]
According to the wireless communication apparatus or the wireless communication method according to the second aspect of the present invention, the communication request is issued at the same relative position on the same communication section as the relative position on the entire section when the communication request occurs within the entire section. Is started.
[0045]
Therefore, a process for averaging the temporal variation of the collision probability that causes a decrease in the transmission speed is performed, and as a result, the problem that the standby time becomes extremely long with respect to the interval between occurrences of communication requests is solved. can do.
[0046]
According to a third aspect of the present invention, there is provided a computer program described in a computer-readable format so as to execute a wireless communication process on a computer system in a wireless communication environment in which a plurality of wireless network groups coexist. hand,
Receiving broadcast information describing frequency channel assignment from a base station operating a wireless network group;
A calculating step of calculating a transmission delay for a communication request based on broadcast information from the base station;
A communication requesting step of initiating a communication request by applying a transmission delay for the delay amount determined by the calculation step,
A computer program characterized by comprising:
[0047]
A computer program according to a third aspect of the present invention defines a computer program described in a computer-readable format so as to realize a predetermined process on a computer system. In other words, by installing the computer program according to the third aspect of the present invention in a computer system, a cooperative action is exerted on the computer system, and the wireless communication according to the second aspect of the present invention is performed. The same operation and effect as those of the device or the wireless communication method can be obtained.
[0048]
Further objects, features, and advantages of the present invention will become apparent from more detailed descriptions based on embodiments of the present invention described below and the accompanying drawings.
[0049]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0050]
The wireless communication system according to the present invention uses a broadcast signal transmitted from a base station to a plurality of terminal stations, averages a temporal change in a collision probability that causes a decrease in transmission speed, and secures communication quality. Things.
[0051]
FIG. 1 schematically shows a configuration of a wireless network according to an embodiment of the present invention. The wireless network according to the present embodiment employs a mode in which one base station operates in a time division manner for a plurality of wireless groups.
[0052]
In the figure, reference numeral 1 denotes a base station that operates a plurality of wireless groups A to C. The terminals 21 to 22 belong to the group A, the terminals 23 to 25 belong to the group B, and the terminal 26 belongs to the group C, and operate. Further, it is assumed that the base station 1 grasps the terminal stations registered in the service area in response to a request from each terminal station, and also grasps a group of the terminal stations.
[0053]
FIG. 2 schematically illustrates a functional configuration of a wireless communication device that operates as a base station or a terminal station on the wireless network according to the present embodiment.
[0054]
The wireless communication device includes a control unit 30 that manages information transmission and performs a process for configuring the wireless network 10, and an interface 31 that exchanges information with a device (application) connected to the outside of the device. A wireless transmission buffer 32 for storing information delivered from an application via the interface 31, and a wireless transmission unit for encoding information stored in the wireless transmission buffer 32 as data for wireless transmission and performing various signal processing 33, an antenna 34 for transmitting the signal assembled by the wireless transmission unit 33 to the medium or receiving a signal from the medium, and receiving the signal propagated through the medium via the antenna 34 and converting the signal as information. Wireless receiving unit 35, which stores the converted information, correctly collects the information, and sends it to the interface. A wireless reception buffer 36 to know, an access control unit 37 for judging whether a transmission path can be used based on access control specified by a communication protocol, and address information of a wireless communication device are stored, and a series of operations are shown. An information storage unit 38 in which instructions (program codes) are stored, and a clock timer unit 39 for notifying the control unit in response to the arrival of a predetermined timing.
[0055]
Further, the illustrated radio communication device has a function for operating as a control station, and operates as a control station as needed when operation as a control station is required, and otherwise operates as a general terminal station. . An execution instruction program for realizing such an operation is stored in the information storage unit 38 in advance.
[0056]
If the wireless communication device is not incorporated in a wireless network, the wireless communication device can determine whether to join a predetermined wireless network and operate, or to construct a wireless network by itself as a control station.
[0057]
The wireless communication device operating as a control station creates broadcast information including frequency channel assignment in the control unit 30 and transmits the broadcast information as a beacon signal from the wireless transmission unit 33 according to a predetermined timing. Then, the wireless network is operated within the reach of the beacon signal.
[0058]
On the other hand, the wireless communication device that is not the control station receives a beacon signal from the control station in the wireless reception unit 35 according to a preset timing, and sets parameters according to the beacon information to be dependent on the control station. To perform a wireless network operation.
[0059]
The access control unit 37 notifies the control unit 30 that the transmission path is available, and sends a transmission instruction to the wireless transmission buffer 32 from the control unit 30 and activates the wireless transmission unit 33 to execute the transmission. At the antenna 34.
[0060]
On the side of the wireless communication device that receives the data, the data transmitted based on the predetermined access control is received by the wireless receiving unit 35 via the antenna 34, and the data is stored in the wireless receiving buffer 36. The wireless receiving unit 35 notifies the control unit 30 of the reception.
[0061]
The data stored in the wireless reception buffer 36 is output in real time to a device (not shown) connected via the interface unit 31 after a predetermined time has elapsed by the timer unit 39.
[0062]
FIG. 3 shows a timing chart for defining a communication section for each group applied in the wireless network according to the present embodiment.
[0063]
The base station 1 determines a communication section to be assigned to each group based on a relationship between a plurality of mobile stations registered for each group. This calculation method can be performed by an arbitrary algorithm, such as a simple calculation based on the number of units or an allocation in consideration of communication contents handled by each mobile station.
[0064]
Further, the base station 1 transmits a broadcast signal to the terminal stations in each group, and distributes information on communication sections. The communication section of each group is arranged immediately before the next notification signal is transmitted.
[0065]
FIG. 4 shows broadcast contents of a broadcast signal applied in the wireless network according to the present embodiment.
[0066]
In the division-related information that divides each terminal existing in the wireless network into groups, a standby time is specified and a position where the next broadcast signal is transmitted is specified. The figure shows a standby section and a communication section of the group A.
[0067]
FIG. 5 shows a communication request process in each terminal station operating on the wireless network according to the present embodiment.
[0068]
First, each terminal station grasps the entire section scale (time until the next broadcast signal is transmitted) based on the broadcast signal. At the same time, each terminal station starts an internal counter. Thereafter, when a communication request occurs, the ratio to the entire section scale is calculated from the value of the internal counter.
[0069]
Separately from this, at the start of the communication section (also obtained from the notification signal and the internal counter), another internal counter is used to count up to the time point when the rate becomes the same as the rate calculated for the entire section scale.
[0070]
When the counter advances to the same ratio, the communication request is activated as before, and processing such as DIFS measurement is started.
[0071]
Further, as another calculation method, when calculating the ratio to the entire section scale at the time of occurrence of a communication request, calculating the time point in the entire section scale to be the same as the communication section scale that has already obtained information from the notification signal , And a communication request can be activated at that time.
[0072]
When this is expressed by a mathematical expression, when the standby time is a, the time until the next notification signal is b, the time elapsed until the communication request is generated is c, and the time for processing the communication request is d,
[0073]
(Equation 1)
d = a + (ba) × c / b
[0074]
It becomes. By the way, each delay time e after the communication request is generated is:
[0075]
(Equation 2)
e = dc
[0076]
Required by Calculating with the example of terminal station B-1 in FIG. 5 (however, using scale as time),
[0077]
[Equation 3]
a = 0.8
b = 1.0
c = 0.25
[0078]
Therefore, the time d for processing the communication request is
[0079]
(Equation 4)
d = 0.8 + (1.0−0.8) × 0.25 / 1.0
[0080]
This is the point of time when the communication request is activated.
[0081]
By performing this communication request processing, a communication request generated at a different time point can be started at a different point in time in the communication section in response to a communication request generated in the standby section, instead of starting the communication request with the start of the communication section. Similar delay processing can be performed for a communication request generated within a communication request. As a result, it becomes possible to start communication requests equally in a communication section for all communication requests. Note that this equalization processing is a calculation method closed within one notification signal interval.
[0082]
As described above, by adjusting the transmission of the communication request, the occurrence of the communication request is made uniform, so that the collision probability of the communication request can be reduced.
[0083]
The method of adjusting the timing of activating the communication request is not limited to the method described in the present specification, and a reduction in the probability of collision can be expected even in the case of non-uniform rearrangement. Even if the backoff value generated after DIFS is given a weighting factor to distribute the transmission concentration, the same effect as in the above-described embodiment can be obtained.
[0084]
FIG. 6 is a flowchart illustrating a processing procedure for a wireless communication device operating as a base station in the wireless network according to the present embodiment to activate a communication request. This processing procedure is actually realized in a form in which the control unit 30 executes a predetermined execution instruction program stored in the information storage unit 38.
[0085]
First, in step S101a, the distribution ratio of the standby section and the communication section in consideration of the number of connected mobile stations and the usage status handled by a separately determined base station is checked.
[0086]
Next, in step S102a, the distribution ratio is included in the notification signal and transmitted. In step S103, the internal scale timer for all sections is reset together with the transmission of the notification signal.
[0087]
Subsequently, in step S104, the end of the communication section is monitored, in step S105, the occurrence of a communication request is monitored, and in step S106, the timer value for the entire section scale at the time of occurrence of the communication request is checked.
[0088]
In step S107, the start timing on the communication section scale is calculated from the scale timer value, and in step S108, it is monitored whether the calculated start timing matches the timer value.
[0089]
Then, in step S109, a communication request is activated at the activation timing, and in step S110, conventional communication processing is performed.
[0090]
After the end of the communication processing, the end of the communication section and the occurrence of a communication request are monitored again in steps S104 and S105. After the end of the communication section, the procedure shifts to the notification signal transmission procedure again.
[0091]
FIG. 7 shows, in the form of a flowchart, a processing procedure for a wireless communication device operating as a terminal station in the wireless network according to the present embodiment to activate a communication request. This processing procedure is actually realized in a form in which the control unit 30 executes a predetermined execution instruction program stored in the information storage unit 38.
[0092]
In step S102b, reception of the notification signal is waited. In step S101b, the distribution ratio included in the notification signal is confirmed.
[0093]
Subsequently, in step S104, the end of the communication section is monitored, in step S105, the occurrence of a communication request is monitored, and in step S106, the timer value for the entire section scale at the time of occurrence of the communication request is checked.
[0094]
In step S107, the start timing at the communication section scale is calculated from the scale timer value, and in step S108, it is monitored whether or not the calculated start timing and the timer value match.
[0095]
Then, in step S109, a communication request is activated at the activation timing, and in step S110, conventional communication processing is performed.
[0096]
After the end of the communication processing, the end of the communication section and the occurrence of a communication request are monitored again in steps S104 and S105. After the end of the communication section, the procedure shifts to the notification signal transmission procedure again.
[0097]
[Supplement]
The present invention has been described in detail with reference to the specific embodiments. However, it is obvious that those skilled in the art can modify or substitute the embodiment without departing from the scope of the present invention. That is, the present invention has been disclosed by way of example, and the contents described in this specification should not be interpreted in a limited manner. In order to determine the gist of the present invention, the claims described at the beginning should be considered.
[0098]
【The invention's effect】
As described in detail above, according to the present invention, in a wireless network environment in which a plurality of wireless networks or wireless groups coexist, access control can be performed by time sharing between the wireless networks or wireless groups by channel sharing. An excellent wireless communication system, wireless communication device, wireless communication method, and computer program can be provided.
[0099]
According to the wireless communication system of the present invention, in each wireless network or wireless group, it is possible to perform a process of averaging a temporal variation of a collision probability that causes a reduction in transmission speed, and therefore, it is possible to generate a communication request. The problem that the waiting time becomes extremely long with respect to the interval can be solved.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a configuration of a wireless network according to an embodiment of the present invention.
FIG. 2 is a diagram schematically illustrating a functional configuration of a wireless communication device that operates as a base station or a terminal station on a wireless network according to an embodiment of the present invention.
FIG. 3 is a diagram showing a timing chart for defining a communication section for each group applied in the wireless network according to the embodiment of the present invention.
FIG. 4 is a diagram showing broadcast contents of a broadcast signal applied in the wireless network according to the embodiment of the present invention.
FIG. 5 is a diagram showing a communication request process in each terminal station operating on the wireless network according to the embodiment of the present invention.
FIG. 6 is a flowchart illustrating a processing procedure for a wireless communication device operating as a base station in a wireless network according to an embodiment of the present invention to activate a communication request.
FIG. 7 is a flowchart illustrating a processing procedure for a wireless communication device operating as a terminal station in a wireless network according to an embodiment of the present invention to activate a communication request.
FIG. 8 is a diagram showing a configuration (conventional example) of a wireless network including a base station and a plurality of terminal stations.
9 is a diagram illustrating an example of a processing operation of a communication request in each terminal station in the wireless network illustrated in FIG. 8;
FIG. 10 is a diagram showing a configuration (conventional example) of a wireless network in which one base station operates in a time-division manner for a plurality of wireless groups.
11 is a diagram showing an example of a processing operation of a communication request in each terminal station in the wireless network shown in FIG.
[Explanation of symbols]
30 control unit 31 interface 32 wireless transmission buffer 33 wireless transmission unit 34 antenna 35 wireless reception unit 36 wireless reception buffer 37 access control unit 38 information storage unit 39 clock timer unit

Claims (9)

A wireless communication system in which a plurality of wireless network groups coexist,
The base station transmits broadcast information to each terminal station of the first radio network group using the first allocated frequency channel, and transmits the broadcast information to the second terminal station using the second allocated frequency channel. Send broadcast information,
The first and second terminal stations perform a calculation of a waiting time process related to a communication start based on the broadcast information from the base station,
A wireless communication system, comprising: Access control is performed by channel sharing between the wireless network groups by time sharing, and a communication section of one wireless network group becomes a standby section of another wireless network group,
Each terminal station in the wireless network group starts a communication request at the same relative position on the communication section as the relative position on the entire section when the communication request occurs,
The wireless communication system according to claim 1, wherein: A wireless communication device operating in a wireless communication environment in which a plurality of wireless network groups coexist,
Means for receiving broadcast information describing frequency channel assignment from a base station operating a wireless network group;
Calculating means for calculating a transmission delay for a communication request based on broadcast information from the base station;
A communication request unit that activates a communication request by applying a transmission delay corresponding to the delay amount calculated by the arithmetic unit;
A wireless communication device comprising: Access control is performed by channel sharing by time division between the wireless network groups, and a communication section of one wireless network group becomes a standby section of another wireless network group,
The calculating means obtains a relative position on the same communication section as the relative position of the communication section at the time when the communication request is generated on all sections as a transmission delay of the communication request,
The wireless communication device according to claim 3, wherein: Assuming that the standby time is a, the time until the next notification signal is b, the time that elapses until the communication request is generated is c, and the time for processing the communication request is d, the arithmetic unit calculates the communication request by the following equation. Calculate the start time,
d = a + (ba) × c / b
The wireless communication device according to claim 3, wherein: A wireless communication method operating in a wireless communication environment in which a plurality of wireless network groups coexist,
Receiving broadcast information describing frequency channel assignment from a base station operating a wireless network group;
A calculating step of calculating a transmission delay for a communication request based on broadcast information from the base station;
A communication requesting step of initiating a communication request by applying a transmission delay for the delay amount determined by the calculation step,
A wireless communication method comprising: Access control is performed by channel sharing by time division between the wireless network groups, and a communication section of one wireless network group becomes a standby section of another wireless network group,
In the calculating step, the relative position on the same communication section as the relative position of the communication request at the time of occurrence on all sections is determined as the transmission delay of the communication request,
The wireless communication method according to claim 6, wherein: If the standby time is a, the time until the next notification signal is b, the time elapsed until the communication request is generated is c, and the time for processing the communication request is d, the communication request is calculated by Calculate the start time,
d = a + (ba) × c / b
The wireless communication method according to claim 6, wherein: A computer program written in a computer-readable format to execute a wireless communication process on a computer system in a wireless communication environment in which a plurality of wireless network groups coexist,
Receiving broadcast information describing frequency channel assignment from a base station operating a wireless network group;
A calculating step of calculating a transmission delay for a communication request based on broadcast information from the base station;
A communication requesting step of initiating a communication request by applying a transmission delay for the delay amount determined by the calculation step,
A computer program comprising:

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