JP4016776B2 - Wireless communication system, wireless communication apparatus, wireless communication method, and computer program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radio communication system, a radio communication apparatus, a radio communication method, and a computer program that communicate with each other between a plurality of radio stations, and more particularly, to each terminal station by a channel sharing method that shares the same frequency channel. The present invention relates to a wireless communication system, a wireless communication apparatus, a wireless communication method, and a computer program that perform access control.
[0002]
More specifically, the present invention relates to a radio communication system, a radio communication apparatus, and a radio communication system that perform access control by channel sharing by time division between each radio network or radio group in a radio network environment in which a plurality of radio networks or radio groups coexist. TECHNICAL FIELD The present invention relates to a wireless communication method and a computer program, and in particular, a wireless communication system, a wireless communication apparatus, and a wireless communication method that suppress temporal fluctuations of a collision probability that causes a decrease in transmission speed in each wireless network or wireless group. And a computer program.
[0003]
[Prior art]
As computers become more sophisticated, multiple computers can be connected to form a LAN (Local Area Network) to share information such as files and data, or to share peripheral devices such as printers, Exchange of information such as mail and data transfer is actively performed.
[0004]
In the conventional LAN, each computer is connected by wire using an optical fiber, a coaxial cable, or a twisted pair cable. However, in such a wired LAN, construction for connection is necessary, and it is difficult to construct the LAN easily, and the cable becomes complicated. In addition, even after LAN construction, the movement range of devices is limited by the cable length, which is inconvenient. Therefore, wireless LANs are attracting attention as a system for releasing users from conventional wired LAN wiring.
[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 the network. According to the wireless LAN, since most of the wired cables can be omitted in a work space such as an office, a terminal such as a personal computer (PC) can be moved relatively easily.
[0006]
In recent years, the demand for wireless LAN systems has increased remarkably with the increase in speed and cost. In particular, recently, in order to establish a small-scale wireless network between a plurality of electronic devices existing around a person and perform information communication, introduction of a personal area network (PAN) has been studied. For example, a wireless LAN system compliant with IEEE 802.11 has already been put into 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 wireless communication device operates as a network base station, and a network is formed within a communicable range. Other wireless communication apparatuses perform network operations based on beacon signals received from base stations, thereby achieving network entry.
[0008]
[Problems to be solved by the invention]
In a wireless network composed of a base station and a plurality of terminal stations, the base station performs communication using a frequency channel assigned in the corresponding wireless zone (including a sector cell). A plurality of terminal stations exist in one cell, and these communicate with one base station at the same time, so access control is necessary.
[0009]
For access control in a wireless network, channels such as FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access), CDMA (Code Division Multiple Access), etc. Channel sharing schemes such as an occupation scheme or ALOHA or CSMA (Carrier Sense Multiple Access) may be mentioned.
[0010]
In packet communication with a random communication request and high burstiness, a channel sharing method in which a plurality of terminal stations share the same frequency channel is often used.
[0011]
In this channel sharing method, since a communication request from a terminal station is made at random, a situation in which signals from a plurality of terminal stations collide (that is, transmission in the same time zone) easily occurs. Since this collision degrades the communication service quality, 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, a terminal station (base station) that has made 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 the DIFS has elapsed after the channel has been freed and further after the backoff has elapsed. However, the carrier availability is checked during standby, and the backoff is reduced only when the channel is empty. Here, backoff is determined based on a uniform distribution. The maximum value that can be taken by backoff is doubled every time transmission fails.
[0013]
FIG. 8 shows a configuration (conventional example) of a wireless network composed of 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 that operate 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 in response to requests from the terminal stations 21 to 26.
[0014]
Also, FIG. 9 shows an example of processing operation of a communication request at each terminal station in the wireless network shown in FIG. In the figure, the carrier sense is a common representation of the carrier sense result recognized by each terminal station for convenience.
[0015]
In the example shown in the figure, the mobile station 21 generates a communication request during the carrier sense busy. In this case, DIFS measurement is started after idle detection, and communication is started after waiting for the backoff to elapse after measurement.
[0016]
In addition, the mobile station 22 generates a communication request in the idle section, and is in carrier sense busy during DIFS measurement. In this case as well, DIFS measurement is entered again after waiting for idle detection, and communication is started after elapse of backoff after measurement.
[0017]
Further, the mobile station 23 starts communication as it is because a communication request is generated in the Idle section and the carrier sense Idle during the DIFS measurement.
[0018]
In this CSMA / CA system, as a precondition for reducing the collision probability using backoff, the generation of communication requests is uniformly distributed, the number of communication requests generated within the standby time is not excessive, etc. Is required. In other words, the waiting time is not extremely long with respect to the communication request generation interval.
[0019]
By the way, when information devices such as personal computers (PCs) are widespread, 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 A situation may occur in which a wireless network is crowded with a narrow working environment and a plurality of wireless networks coexist on the same channel.
[0020]
In such a case, for example, a network coexistence method is conceivable in which one transmission frame is shared among the networks in a time division manner, or one base station is operated in a time division manner for a plurality of radio groups.
[0021]
In the former case, since the terminals in each network are in a standby state in the time domain assigned to other networks, there is a possibility that communication requests will be made simultaneously when entering the time domain assigned to them. Also, in the latter case, the terminals in each wireless group are in a standby state in the time domain assigned to other groups, so there is a possibility that communication requests will occur simultaneously when entering the time domain assigned to the own group. is there.
[0022]
In other words, even if the generation of communication requests is uniform for each wireless network or each wireless group, the collision probability that causes a decrease in transmission speed may cause a temporal change. There arises a problem that the waiting 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 is a base station that operates a plurality of radio 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 knows the terminal stations registered in the service area according to the request from each terminal station, and also knows the terminal station group.
[0025]
FIG. 11 shows an example of processing operation of a communication request at each terminal station in the wireless network shown in FIG. In the figure, the carrier sense is a common representation of the carrier sense result recognized by each terminal station for convenience.
[0026]
In the same 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 of this division from the notification 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 generate communication requests during the standby period. For this reason, communication-related processing is kept waiting until the communication section is reached.
[0028]
In such a case, each mobile station starts the DIFS interval simultaneously with the start of the communication interval, and then takes the initial backoff value with a random number and starts the measurement of the backoff interval. In the illustrated example, when the mobile station B-1 or the mobile station B-2 is idle until the backoff measurement ends, these mobile stations start communication.
[0029]
Further, when the mobile station B-3 becomes carrier sense busy during the backoff measurement, the mobile station B-3 stops the backoff measurement, and then holds the state until the carrier sense idle.
[0030]
At this time, the communication start between the mobile station B-1 and the mobile station B-2 is the same time, and a collision occurs. This is because the range that the random number of the first backoff value can take is narrow. That is, the collision probability that causes a decrease in the transmission speed changes with time, and the collision occurs at a higher probability when viewed from the average value of the entire communication.
[0031]
In this way, if the standby time becomes extremely long, the communication requests generated during the standby time are mutually sensed when the communication is started after the DIFS has elapsed after the channel has been freed and further after the backoff has elapsed. However, the number of communication starts occurring simultaneously at the same time increases, and as a result, communication collides as described above.
[0032]
In such a case, the collision probability that occurs when the standby time is not affected becomes higher. This fluctuation of the collision probability with time results in a decrease in average transmission speed.
[0033]
The present invention has been made in view of the technical problems as described above, and its main object is to perform time division between each wireless network or wireless group in a wireless network environment where a plurality of wireless networks or wireless groups coexist. It is an object to provide an excellent wireless communication system, wireless communication apparatus and wireless communication method, and computer program capable of suitably performing access control by channel sharing.
[0034]
A further object of the present invention is to suppress the temporal fluctuation of the collision probability that causes a decrease in the transmission speed in each wireless network or wireless group, and extremely increase the standby time with respect to the communication request generation interval. An object of the present invention is to provide an excellent wireless communication system, wireless communication apparatus and wireless communication method, and computer program that can solve the problem.
[0035]
[Means and Actions 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 by time sharing between each wireless network group, the communication section of one wireless network group becomes the standby section of the other wireless network group,
Each terminal station in the wireless network group activates a communication request at a relative position on the same communication section as when the communication request is generated in all sections.
This is a wireless communication system.
[0036]
However, “system” here 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 whether or not.
[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, and the base station Broadcast information is transmitted to the second terminal station using the second assigned frequency channel of the radio zone. Then, the first mobile station and the second mobile station perform a wait time process regarding the start of communication based on the notification information from the base station.
[0038]
Each terminal station generates a communication request at an arbitrary timing in all sections including the communication section assigned to its own network group and other standby sections, but if a communication request occurs in the standby section, The communication request is awaited until the communication section arrives.
[0039]
According to the first aspect of the present invention, a terminal station in a wireless network makes a communication request at a relative position on the same communication section as a relative position on all sections when a communication request occurs in all sections. It is supposed to start.
[0040]
Therefore, processing is performed to average the temporal fluctuation of the collision probability that causes a decrease in the transmission speed, and as a result, the problem that the standby time becomes extremely long with respect to the communication request generation interval is solved. can do.
[0041]
The second aspect of the present invention is a wireless communication apparatus or a wireless communication method that operates in a wireless communication environment in which a plurality of wireless network groups coexist,
Means or step for receiving broadcast information describing allocation of frequency channels from a base station operating a radio network group;
Calculation means or step for obtaining a transmission delay for a communication request based on broadcast information from the base station;
A communication request means or step for initiating a communication request by applying a transmission delay corresponding to the delay amount obtained by the calculation means or step;
A wireless communication apparatus or a wireless communication method.
[0042]
Access control is performed by channel sharing in a time-sharing manner between each wireless network group, and a communication section of a certain wireless network group is a standby section of other wireless network groups. Then, according to the wireless communication device or the wireless communication method according to the second aspect of the present invention, the calculating means or step is configured such that the time at which the communication request is generated is the same relative position on the communication section as the relative position on all the sections. The position is obtained as the transmission delay of the communication request.
[0043]
  If this is specifically expressed as a mathematical expression, 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. And the computing means or step is
    d = a + (b−a) × c /b
The communication request activation time is calculated by the following formula.
[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 made at the relative position on the same communication section as the relative position on all the sections when the communication request is generated in all the sections. Is supposed to start.
[0045]
Therefore, processing is performed to average the temporal fluctuation of the collision probability that causes a decrease in the transmission speed, and as a result, the problem that the standby time becomes extremely long with respect to the communication request generation interval is solved. can do.
[0046]
A third aspect of the present invention is a computer program written in a computer-readable format so that wireless communication processing in a wireless communication environment in which a plurality of wireless network groups coexist is executed on a computer system. And
Receiving broadcast information describing frequency channel assignments from a base station operating a wireless network group; and
A calculation step for obtaining a transmission delay for a communication request based on broadcast information from the base station;
A communication request step for initiating a communication request by applying a transmission delay corresponding to the delay amount determined by the calculation step;
A computer program characterized by comprising:
[0047]
The computer program according to the third aspect of the present invention defines a computer program described in a computer-readable format so as to realize predetermined processing on a computer system. In other words, by installing the computer program according to the third aspect of the present invention in the computer system, a cooperative action is exhibited on the computer system, and the wireless communication according to the second aspect of the present invention. The same effect as that of the device or the wireless communication method can be obtained.
[0048]
Other objects, features, and advantages of the present invention will become apparent from more detailed description based on embodiments of the present invention described later and the accompanying drawings.
[0049]
DETAILED DESCRIPTION OF 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 communication signals transmitted from a base station to a plurality of terminal stations, and averages the temporal fluctuations of the collision probability that causes a decrease in transmission speed to ensure communication quality. Is.
[0051]
FIG. 1 schematically shows the configuration of a wireless network according to an embodiment of the present invention. The wireless network according to the present embodiment employs a form in which one base station operates in a time division manner for a plurality of wireless groups.
[0052]
In the figure, reference numeral 1 is a base station that operates a plurality of radio 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 knows the terminal stations registered in the service area according to the request from each terminal station, and also knows the terminal station group.
[0053]
FIG. 2 schematically illustrates a functional configuration of a wireless communication apparatus that operates as a base station or a terminal station on the wireless network according to the present embodiment.
[0054]
The wireless communication apparatus includes a control unit 30 that manages information transmission and performs processing for configuring the wireless network 10, and an interface 31 that exchanges information between devices (applications) connected to the outside of the apparatus. A wireless transmission buffer 32 for storing information delivered from an application via the interface 31, and a wireless transmission unit for encoding the information stored in the wireless transmission buffer 32 as data for wireless transmission and performing various signal processing 33, the antenna 34 that transmits the signal assembled by the wireless transmitter 33 and receives the signal from the medium, and the signal that has propagated through the medium via the antenna 34 is received and further converted as information And the radio receiver 35 that stores the converted information and correctly collects the information to the interface. The wireless reception buffer 36 to be known, the access control unit 37 that determines whether or not the transmission path is available based on the access control defined by the communication protocol, the address information of the wireless communication device, and the like are stored, and a series of operations is shown. An information storage unit 38 that stores instructions (program codes) and a clock timing unit 39 that notifies the control unit in response to the arrival of a predetermined timing are provided.
[0055]
Further, the illustrated wireless communication apparatus has a function for operating as a control station, and when necessary to operate as a control station, operates as a control station as appropriate, otherwise 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 the wireless network, it can determine whether to enter and operate on a predetermined wireless network, or to establish a wireless network by itself as a control station.
[0057]
The wireless communication apparatus operating as a control station creates broadcast information including frequency channel assignment in the control unit 30 and transmits the information as a beacon signal from the wireless transmission unit 33 according to a predetermined timing. The wireless network is operated in the reach range of the beacon signal.
[0058]
On the other hand, the wireless communication device that is not the control station receives the beacon signal from the control station at the wireless reception unit 35 according to the preset timing, and sets the parameters according to the beacon information, thereby depending on the control station. Wireless network operation.
[0059]
The access control unit 37 notifies the control unit 30 that the transmission path is available, sends a transmission instruction from the control unit 30 to the wireless transmission buffer 32, and operates the wireless transmission unit 33 to actually perform the transmission. The data is transmitted from the antenna 34.
[0060]
On the side of the wireless communication device that receives data, the data received based on the predetermined access control is received by the wireless reception unit 35 via the antenna 34, and the data is stored in the wireless reception buffer 36. The wireless reception unit 35 notifies the control unit 30 that it has been received.
[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 time counting 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 from the relationship between a plurality of mobile stations registered for each group. This calculation method can be performed by an arbitrary algorithm such as simple allocation by the number of units or allocation taking into consideration the communication contents handled by each mobile station.
[0064]
In addition, the base station 1 transmits a notification signal to each group of terminal stations and distributes information related to the communication section. The communication section of each group is arranged immediately before the next notification signal is transmitted.
[0065]
FIG. 4 shows notification contents of a notification signal applied in the wireless network according to the present embodiment.
[0066]
In the division-related information for dividing each terminal existing in the wireless network into a group, designation of a standby time and a position at which the next notification signal is transmitted are designated. In the figure, a standby section and a communication section of group A are shown.
[0067]
FIG. 5 shows communication request processing 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 is generated, 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 when the ratio is the same as the ratio calculated for the entire section scale.
[0070]
When the counter advances to the time when the same ratio is reached, the communication request is activated as before and processing such as DIFS measurement is started.
[0071]
Also, as another calculation method, when the ratio of the communication request generation time to the entire section scale is calculated, the time calculation at the all section scale is the same ratio to the communication section scale that has already obtained information from the notification signal. It is also possible to activate the communication request at that time.
[0072]
Expressing this as a mathematical expression, 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,
[0073]
[Expression 1]
d = a + (ba) * c / b
[0074]
It becomes. Incidentally, each delay time e after the communication request is generated is
[0075]
[Expression 2]
e = dc
[0076]
It is calculated by. In the example of the terminal station B-1 in FIG. 5 (however, the scale is used 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]
[Expression 4]
d = 0.8 + (1.0−0.8) × 0.25 / 1.0
[0080]
This is the time when the communication request is activated.
[0081]
  By performing this communication request processing, communication requests can be started at different points in time, instead of being started at the start of the communication section in the communication section with respect to the communication request generated in the standby section, and communicationsectionThe same delay processing can be performed for communication requests generated within the network. As a result, for all communication requests, it becomes possible to activate the communication requests evenly within the communication section. This equalization process is a calculation method closed within one notification signal interval.
[0082]
Thus, by adjusting the transmission of the communication request, the generation of the communication request is made uniform, so that it is possible to reduce the collision probability of the communication request.
[0083]
Note that the timing adjustment method for starting the communication request is not limited to the method described in this specification, and a reduction in the collision probability can be expected even when the communication requests are unevenly rearranged. Further, even if the backoff value generated after DIFS is given a weighting factor to distribute the transmission concentration, the same effect as the above-described embodiment can be obtained.
[0084]
FIG. 6 shows a processing procedure for a wireless communication apparatus operating as a base station in the wireless network according to the present embodiment to activate a communication request in the form of a flowchart. 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 for each mobile station group handled by a separately defined base station is confirmed.
[0086]
Next, in step S102a, the distribution ratio is included in the notification signal and transmitted, and in step S103, the internal-to-all interval scale timer included therein is reset together with the notification signal transmission.
[0087]
Subsequently, in step S104, the end of the communication section is monitored, in step S105, the generation of the communication request is monitored, and in step S106, the timer value of the scale for all sections at the time when the communication request is generated is confirmed.
[0088]
In step S107, the activation timing point on the communication interval scale is calculated from the scale / timer value, and in step S108, it is monitored whether the calculated activation timing point coincides with the timer value.
[0089]
In step S109, a communication request is activated at the activation timing, and conventional communication processing is performed in step S110.
[0090]
After the communication process is completed, the end of the communication section and the generation of a communication request are monitored again in steps S104 and S105. After the end of the communication section, the procedure proceeds to the notification signal transmission procedure again.
[0091]
FIG. 7 shows a processing procedure for a wireless communication apparatus operating as a terminal station in the wireless network according to the present embodiment to activate a communication request in the form of a flowchart. 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, the reception of the notification signal is awaited. In step S101b, the distribution ratio included in the notification signal is confirmed. In step S103, the internal interval scale timer included therein is reset together with the reception of the notification signal.
[0093]
Subsequently, in step S104, the end of the communication section is monitored, in step S105, the generation of the communication request is monitored, and in step S106, the timer value of the scale for all sections at the time when the communication request is generated is confirmed.
[0094]
In step S107, the activation timing point on the communication interval scale is calculated from the scale / timer value, and in step S108, it is monitored whether the calculated activation timing point coincides with the timer value.
[0095]
In step S109, a communication request is activated at the activation timing, and conventional communication processing is performed in step S110.
[0096]
After the communication process is completed, the end of the communication section and the generation of a communication request are monitored again in steps S104 and S105. After the end of the communication section, the procedure proceeds to the notification signal transmission procedure again.
[0097]
[Supplement]
The present invention has been described in detail above with reference to specific embodiments. However, it is obvious that those skilled in the art can make modifications and substitutions of the embodiment without departing from the gist of the present invention. That is, the present invention has been disclosed in the form of exemplification, and the contents described in the present specification should not be interpreted in a limited manner. In order to determine the gist of the present invention, the claims section described at the beginning should be considered.
[0098]
【The invention's effect】
As described above in detail, 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 channel sharing between each wireless network or wireless group by time division. An excellent wireless communication system, wireless communication apparatus, 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 temporal fluctuations in the collision probability that causes a decrease in transmission speed, so that a communication request is generated. 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 apparatus operating as a base station or a terminal station on a wireless network according to the 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 illustrating notification contents of a notification 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 a wireless network according to the embodiment of the present invention.
FIG. 6 is a flowchart showing a processing procedure for a wireless communication apparatus operating as a base station in the wireless network according to the embodiment of the present invention to activate a communication request.
FIG. 7 is a flowchart showing a processing procedure for a wireless communication apparatus operating as a terminal station in the wireless network according to the 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.
FIG. 9 is a diagram showing an example of processing operation of a communication request at each terminal station in the wireless network shown in FIG.
FIG. 10 is a diagram showing a configuration (conventional example) of a wireless network in which one base station operates in a time-sharing manner for a plurality of wireless groups.
11 is a diagram showing an example of a processing operation of a communication request at each terminal station in the wireless network shown in FIG.
[Explanation of symbols]
30 ... Control unit
31 ... Interface
32 ... Wireless transmission buffer
33 ... Wireless transmitter
34 ... Antenna
35 ... Wireless receiver
36 ... Wireless reception buffer
37 ... Access control unit
38. Information storage unit
39 ... Clock timer

Claims (9)

A plurality of wireless network groups each including one or more terminal stations, and a base station that operates the plurality of wireless network groups;
The base station defines a communication section to be assigned to each wireless network group, and transmits a notification signal including information on the communication section to a terminal station of each wireless network group,
The terminal station activates the communication request at the timing of performing delay processing according to the ratio to the entire interval at the time of occurrence of the communication request from the start of the communication interval assigned to the wireless network group.
A wireless communication system. Access control is performed by channel sharing by time sharing between each wireless network group, the communication section of one wireless network group becomes the standby section of the other wireless network group,
Each terminal station in the wireless network group activates a communication request at a relative position on the same communication section as the relative position on the entire section when the communication request occurs.
The wireless communication system according to claim 1. A wireless communication device that operates as a terminal station in a wireless communication environment in which a plurality of wireless network groups coexist,
Means for receiving notification information including information on communication sections assigned to each wireless network group from a base station that operates the plurality of wireless network groups;
Based on the broadcast information from the base station, calculating means for obtaining a transmission delay according to the ratio to all sections at the time of occurrence of the communication request ,
Communication request means for starting a communication request by applying a transmission delay corresponding to the delay amount determined by the calculation means from the start of the communication section assigned to the wireless network group in which the own station is accommodated ;
A wireless communication apparatus comprising: Access control is performed by channel sharing by time division between each wireless network group, and the communication section of one wireless network group becomes the standby section of the other wireless network group,
The arithmetic means obtains the relative position on the same communication section as the relative position on the entire section when the communication request is generated as a transmission delay of the communication request.
The wireless communication apparatus according to claim 3. Assuming that the waiting 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 arithmetic means calculates the communication request by the following equation: Calculate the starting time,
d = a + (ba) * c / b
The wireless communication apparatus according to claim 3. A wireless communication method that operates as a terminal station in a wireless communication environment in which a plurality of wireless network groups coexist,
Receiving broadcast information including information on communication sections allocated to each wireless network group from a base station that operates the plurality of wireless network groups;
Based on the broadcast information from the base station, a calculation step for obtaining a transmission delay according to a ratio to all sections at the time of occurrence of a communication request ;
From the start of the communication section assigned to the wireless network group in which the own station is accommodated, a communication request step for starting a communication request by applying a transmission delay corresponding to the delay amount obtained by the calculation step;
A wireless communication method comprising: Access control is performed by channel sharing by time division between each wireless network group, and the communication section of one wireless network group becomes the standby section of the other wireless network group,
The calculation step determines the relative position on the same communication section as the relative position that the time when the communication request occurs on all sections as a transmission delay of the communication request.
The wireless communication method according to claim 6. Assuming that the waiting 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 step is expressed as Calculate the starting time,
d = a + (ba) * c / b
The wireless communication method according to claim 6. A computer program described in a computer readable format so as to execute wireless communication processing to operate as a terminal station on the computer have you under a wireless communication environment where a plurality of radio network groups coexist, the computer The
Means for receiving notification information including information on communication sections assigned to each wireless network group from a base station that operates the plurality of wireless network groups;
Based on the broadcast information from the base station, calculating means for obtaining a transmission delay according to the ratio to all sections at the time of occurrence of the communication request ,
Communication request means for starting a communication request by performing a transmission delay corresponding to the delay amount obtained by executing the calculation step from the start of a communication section assigned to a wireless network group in which the own station is accommodated ;
A computer program that functions as a computer program.

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