WO2006059473A1

WO2006059473A1 - Wireless communication apparatus, wireless communication method, wireless communication system, program product, and storing medium storing program product

Info

Publication number: WO2006059473A1
Application number: PCT/JP2005/020693
Authority: WO
Inventors: Akira Nishikawa; Yoshihiro Ohtani
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2004-12-02
Filing date: 2005-11-11
Publication date: 2006-06-08
Also published as: JPWO2006059473A1; JP4401392B2

Abstract

A wireless communication apparatus, a wireless communication method, a wireless communication system, a program product, and a storing medium storing the program product, wherein the transmission paths can be switched without affecting the real time characteristic of data transmission. When switching the transmission paths from a first transmission path (104) to a second transmission path (105), a transmitting station (102), while having reserved the communication band of the first transmission path (104), firstly reserves the communication band of a transmission path (107). By using, in a transmission path (106), the communication band of the first transmission path (104), the transmitting station (102) uses the second transmission path (105) to transmit the data to a receiving station (103). When switching the transmission paths from the second transmission path (105) to the first transmission path (104), the transmitting station (102) uses, as the communication band of the first transmission path (104), the communication band of the transmission path (106), thereby transmitting the data to the receiving station (103) through the first transmission path (104).

Description

Specification

Wireless communication apparatus, wireless communication method, wireless communication system, program product and storage medium storing program product

Technical field

The present invention relates to a wireless communication apparatus, a wireless communication method, a wireless communication system, a program product, and a storage medium storing the program product. Background art

[0002] Conventionally, devices such as personal computers installed in offices and homes have been connected by a LAN (Local Area Network) cable or the like. When connecting devices using a LAN cable etc., wiring was complicated and there were problems such as low freedom of movement of the devices. In recent years, in order to solve such problems, devices such as personal computers installed in offices and homes use wireless transmission technology such as wireless LAN standardized in IEEE802.11.

Wireless LAN is an extension of LAN to wireless, and is also suitable for data transfer such as data file exchange between PCs and Web access. In the field, products such as wireless LAN cards for notebook computers and wireless LAN access points are widely sold.

Further, recently, development of a wireless transmission technology for transmitting real-time data with high quality has been underway. The IEEE802.1 ie, which is currently being standardized, is intended to enable Quality of Service (QoS) control on a wireless LAN, and is drawing attention. IEEE 802. IE provides two access control methods for Enhanced QoS (EDCA) and QoS (Hybrid Coordination Function (HCF) controlled Channel Access) by using Enhanced Distributed Channel Access (EDCA)! (For example, Non Patent Literature 1).

EDCA is a distributed control type access control method that allows each wireless communication device to stochastically access a channel. Specifically, a wireless communication device (hereinafter also referred to as a "transmitting station") that is to transmit data is first notified of other wireless communication in the wireless communication system. Check whether the receiving device is transmitting data. When the transmitting station transmits data and confirms that the other wireless communication device does not, it sets a random waiting time to transmit data. At this time, the transmitting station changes the length of the waiting time according to the priority of the data. The transmitting station starts transmitting data after the waiting time has elapsed. Central control station (QAP (QoS Access Point)) power The above waiting time is set to a value with a certain range for each priority, and all waiting stations are notified and specified. QAP can adjust the overall wireless communication status to some extent by changing the above latency value and range. In EDCA, the waiting time set by the transmitting station is random, and there is a possibility that the data transmitted from each transmitting station may collide. When the data transmitted from each transmitting station collides, the data transmission is not performed normally. In this way, it is not guaranteed that EDCA can transmit data reliably in time, so it is not very good at transmitting real-time data.

[0006] On the other hand, HCCA is a central control type in which each wireless communication device can access a channel deterministically under the command of QAP (grant of communication right (notification of Poll frame)). It is an access control method. Specifically, the transmitting station requests the QAP to provide communication time (hereinafter also referred to as “communication band”) capable of transmitting data. The QAP controls the assignment or release of the communication band necessary for the transmitting station to transmit data. According to the specifications, QAP is free to assign a communication band to the transmitting station, but in general, if there is an idle communication band in the wireless communication system according to the communication band requested by the transmitting station, Assign a communication band. The transmitting station transmits data using a transmission path determined within the communication band range (within the communication time) given QAP. Since HCCA controls the communication bandwidth that QAP assigns to each transmitting station, there is no collision of data transmitted from each transmitting station. Therefore, HCCA is suitable for transmission of real-time data and the like, which are required to transmit data at a high data rate and within a delay time (Delay Bound).

[0007] Hereinafter, performing QoS control using HCCA is referred to as "securing a communication band", and

The end of QoS control using HCCA is referred to as "releasing communication band".

[0008] A transmission path to a wireless communication device (hereinafter also referred to as "receiving station"! /!) That receives data from a transmitting station The first transmission line (Dire _C tlink) directly from the transmitting station to the receiving station and the wireless communication device (hereinafter simply referred to as the "relay station") from the transmitting station to the relay station It can be thought of as the “second transmission path” that leads to the receiving station via this. If QoS control is to be performed using HCCA, the communication band power SQAP power of each transmission path also needs to be provided.

[0009] When transmitting data from the transmitting station to the receiving station, which one of the first transmission path (Directlink) and the second transmission path is suitable for transmitting data is as follows: It depends on the communication status. In general, when the distance between the transmitting station and the receiving station is short, it is better to transmit data using the first transmission line (Directlink) because the communication status is better! I can do it often. On the other hand, if there is a relay station between the transmitting station and the receiving station, where the distance between the transmitting station and the receiving station is longer, it is better to transmit data using the second channel, and the communication status is better. A lot of times when you can send!

For example, it is assumed that the transmitting station is a DVD (Digital Versatile Disc) player or the like that reproduces video and audio. On the other hand, it is assumed that the receiving station is a television or the like which receives the data transmitted by the DVD player which is the transmitting station and also sends the video and audio to the screen and the speaker. Since the television and the like and the DVD player and the like are wireless, they can be used while moving the television and the like.

When used while moving a television or the like, the communication status with the DVD player, etc. changes from time to time. Therefore, in order to transmit data with high quality to a television etc., it is one solution for the DVD player, etc. to appropriately switch the first transmission path (Directlink) and the second transmission path according to the communication status. is there. In addition, it is important to perform QoS control using IEEE802.11 even after switching the transmission path.

[0012] Thus, regarding the method of changing QoS control using IEEE802.1 ie when switching the transmission path, there is no document which discloses the method at present. If EDCA is used, it can be easily analogized by raising the priority of the transmitting station to allow access to the switched transmission path with higher probability than other wireless communication devices. When HCCA is used, a method can be easily analogized to open the communication band of the transmission line before switching and request the provision of the communication band of the transmission line after power switching. As another method, the method of requesting both the communication bands of the first transmission line and the second transmission line can be easily analogized it can.

Non-Patent Document l: "P802.11e, (Dll) Draft Amendment to Standard [for] for Information Technology" "[Online]" [Search on November 11, 2004], Internet URL: http: // www .ili-info.com / ieee802drafts / index.shtml)

Disclosure of the invention

Problem that invention tries to solve

According to the method of releasing the communication band of the transmission path before switching while requesting the provision of the communication band of the transmission path after power switching, the communication band of the transmission path before switching is released. There is a period in which the communication band is not given while the request for giving the communication band of the transmission path after switching is given and the QAP power communication band is given, and the real-time nature of data transmission is impaired. There is a point.

[0014] The transmitting station can not transmit data to the receiving station during a period in which the communication band is not assigned. As a result, the delay time may exceed the DelayBound value allowed for transmission (for example, the recommended value of 64 msec in the case of transmission of a television video signal). For example, as described above, when the receiving station is a television or the like, if the delay time exceeds the DelayBound value, the real time property of data transmission is impaired, and the video and audio are disturbed.

In addition, the communication band of the transmission path before switching is opened to request the provision of the communication band of the transmission path after power switching, and until the QAP power communication band is assigned, another user or application is requested. May consume communication bandwidth to transmit other data. As a result, the QAP power also becomes difficult to assign the communication band of the transmission path after switching, and the period in which the communication band is not assigned becomes longer and the real-time property of data transmission is impaired.

When switching from the first transmission line (Directlink) to the second transmission line, the communication band of the transmission line from the transmitting station to the relay station and the communication band of the transmission line from the relay station to the receiving station are QAP. Need to request. In other words, after switching, it is necessary to request QAP to provide about twice the communication bandwidth as before switching. Therefore, it becomes difficult to assign the communication band of the transmission path after QAP power switching, and if the communication band of the transmission path before switching is released, the period in which the communication band is not assigned becomes even longer, and data Real-time nature of transmission It gets lost.

[0017] Furthermore, even if QAP is requested to assign the communication band of the transmission path before switching because the communication band of the transmission path after QAP power switching is not assigned, other users and applications may have already made it. The communication band may be consumed to transmit data. As a result, the QAP power and the communication band of the transmission line before switching are also provided. In the worst case, neither the communication band of the first transmission line (Directlink) nor the communication line of the second transmission line can be secured. There is a problem that data transmission to the receiving station ends.

Further, as for the method of requesting the communication band of both the first transmission line and the second transmission line, since the communication band amount required is large, the communication band of the QAP power transmission line and the second transmission line It is hard to be granted. Furthermore, even if the communication band of the first transmission path and the second transmission path is given, since the data transmission is performed by switching the communication band of one of the transmission paths, the communication band of the other transmission path is wasted. Also has the problem of consuming communication bandwidth

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a wireless communication apparatus capable of switching transmission paths without impairing the real time property of data transmission. It is.

[0020] Another object of the present invention is to provide a wireless communication method capable of switching and performing communication without changing the real time property of data transmission.

Another object of the present invention is to provide a wireless communication system capable of switching and communicating transmission paths without impairing the real time property of data transmission.

Another object of the present invention is to provide a program for causing a computer to function as a wireless communication device capable of switching transmission paths without impairing the real time property of data transmission.

[0023] Still another object of the present invention is to provide a storage medium storing a program for causing a computer to function as a wireless communication device capable of switching the transmission path without impairing the real time property of data transmission. is there.

Means to solve the problem In order to achieve the above object, a wireless communication apparatus according to one aspect of the present invention includes a transmitting / receiving unit for transmitting / receiving data to / from another wireless communication apparatus via a plurality of transmission paths, and providing and releasing a communication band. A communication band is assigned to a certain transmission line from the central control station that performs communication, and a communication band control unit that controls the communication band to use the communication band as a communication band for another transmission line. Equipped with

Preferably, the transmission path includes a first transmission path directly transmitting data to another wireless communication device, and a second transmission path transmitting data to the other wireless communication device via the relay station. The communication band control unit instructs the relay station to request the central control station to assign a communication band to the third transmission path from the relay station of the second transmission path to another wireless communication apparatus. Other band assignment request instruction section.

Preferably, the communication band control unit includes an other band release request instructing unit instructing the relay station to request the central control station to release the communication band of the third transmission path.

Preferably, the transmission path includes a first transmission path directly transmitting data to another wireless communication device, and a second transmission path transmitting data to the other wireless communication device via the relay station. The wireless communication device further includes a wireless communication control unit that switches a transmission path used to transmit data to another wireless communication device between the first transmission path and the second transmission path.

Preferably, when the wireless communication control unit switches the transmission path to the first transmission path second transmission path, in the process of switching, the relay station among the communication band on the first transmission path and the second transmission path After passing through the state in which the communication band on the third transmission path from the terminal to the other wireless communication apparatus is assigned, the state in which all communication bands in the first transmission path and the second transmission path are assigned is passed.

Preferably, when the wireless communication control unit switches the transmission path to the second transmission path strength first transmission path, the fourth transmission from the own apparatus to the relay station in the second transmission path in the process of switching. After passing through the state in which only the communication band on the road is assigned, the state in which the communication bands of the first transmission path and the fourth transmission path are assigned is passed.

Preferably, when the communication band control unit switches the transmission path used to transmit data to another wireless communication device between the first transmission path and the second transmission path, the transmission before switching is performed. The central control station indicates that data is sent to another wireless communication device using Execute control to send to.

[0031] Preferably, the wireless communication device is a notification unit that notifies the status of processing to switch a transmission channel used to transmit data to another wireless communication device between the first transmission channel and the second transmission channel. Further comprising

Preferably, the wireless communication device includes a relay destination address setting unit that sets a relay destination address for specifying a relay station that relays data, and a reception for specifying a wireless communication device that receives data. And a receiver address setting unit for setting a destination address. When the radio communication control unit switches to the first transmission path second transmission path, the relay destination address setting unit transmits the relay destination address in order to transmit data to the relay station in the communication band to which the central control station has been assigned. Is set to the address of the relay station, and the receiver address setting unit sets the receiver address to the address of another wireless communication apparatus.

Preferably, when the wireless communication control unit switches from the second transmission line to the first transmission line, in order to directly transmit data to another wireless communication apparatus in the communication band already assigned from the central control station, The relay destination address setting unit does not set the relay destination address, and the reception destination address setting unit sets the reception destination address to the address of another wireless communication apparatus.

Preferably, the communication band control unit requests the central control station to assign a communication band for transmitting data to another wireless communication apparatus, and whether or not the central control station communication band is assigned. And a free band confirmation unit that checks whether there is a free communication band in the wireless communication system to which the own device currently belongs.

Preferably, the wireless communication control unit cancels switching between the first transmission path and the second transmission path when the free band confirmation unit confirms the shortage of the free band.

A wireless communication apparatus according to another aspect of the present invention receives wireless communication apparatus power data of a transmitting side via a transmission line, and receives the received data via a transmission line on the wireless communication apparatus at the receiving side. Send to The transmission path includes a first transmission path directly transmitting data to another wireless communication device, and a second transmission path transmitting data to the other wireless communication device via the relay station. The wireless communication device requires the central control station that assigns and releases the communication band to assign the communication band to the third transmission path to the other wireless communication device among the relay stations in the second transmission path. If the other wireless communication device is instructed to do so, the central control station And a provision data transmission control unit for controlling transmission of data indicating that the communication band has been assigned to the third transmission path.

Preferably, the wireless communication device is instructed to the central control station when another wireless communication device instructs the central control station to release the communication band of the third transmission path. The other band release request control unit that requests release of the communication band of the transmission path, and an open data transmission control unit that controls transmission of data indicating that the communication band of the third transmission path is released.

According to another aspect of the present invention, there is provided a wireless communication method for transmitting and receiving data between a first wireless communication device and a second wireless communication device through a plurality of transmission paths. This method comprises the steps of: detecting a communication band assigned to a transmission path among a plurality of transmission paths from a central control station that assigns and releases the communication band; And a communication band control step of controlling the detected communication band so as to be used as the communication band of the transmission path.

Preferably, the plurality of transmission paths are a first transmission path for transmitting data directly from the first wireless communication device to the second wireless communication device, and a second wireless communication from the first wireless communication device. And a second transmission path for transmitting data to the device via the relay station. The wireless communication method instructs the relay station to request the central control station to assign a communication band to the third transmission path from the relay station to the second wireless communication apparatus in the second transmission path. And the other band assignment request instruction step.

Preferably, the wireless communication method further includes an other band release request instructing step of instructing the relay station to request the central control station to release the communication band of the third transmission path.

Preferably, the plurality of transmission paths are a first transmission path directly transmitting data from the first wireless communication device to the second wireless communication device, and a second wireless communication from the first wireless communication device. And a second transmission path for transmitting data to the device via the relay station. The wireless communication method further includes a wireless communication control step of switching a transmission channel used to transmit data to the second wireless communication device between the first transmission channel and the second transmission channel.

Preferably, in the case where the wireless communication control step switches from the first transmission path to the second transmission path After the communication band on the first transmission path and the communication band on the third transmission path from the relay station of the second transmission path to the second wireless communication apparatus are given in the switching process, The state where all the communication bands on the first transmission path and the second transmission path are assigned is passed.

Preferably, when the wireless communication control step switches to the second transmission path power to the first transmission path, in the process of switching, the fourth transmission path from the first wireless communication device of the second transmission paths to the relay station After passing through the state in which only the communication band is assigned, the communication bands on the first and fourth transmission paths are assigned, and the state passes.

Preferably, when the wireless communication control step switches to the first transmission path second transmission path, in the process of switching, at least a communication band on the first transmission path, and a relay among the second transmission paths to the central control station. A communication band on the third transmission path from the station to the second wireless communication apparatus is given, and the state passes.

Preferably, when the wireless communication control step switches the second transmission path power to the first transmission path, on the fourth transmission path from the first wireless communication device of the second transmission path to the relay station in the process of switching. The state in which only the communication band is assigned is passed.

Preferably, in the wireless communication method, a transmission path used for transmitting data from the first wireless communication device to the second wireless communication device is provided between the first transmission path and the second transmission path. And transmitting, to the central control station, data indicating that data is being transmitted from the first wireless communication device to the second wireless communication device using the transmission path before switching. Ru.

Preferably, in the wireless communication method, a transmission path used to transmit data from the first wireless communication device to the second wireless communication device is provided between the first transmission path and the second transmission path. It further comprises the step of notifying the status of the switching process.

Preferably, in the wireless communication method, a relay destination address setting step of setting a relay destination address for specifying a relay destination for relaying data, and a receiver for specifying a wireless communication apparatus for receiving data. The receiver further comprises an address setting step for setting an address. When the wireless communication control step switches the transmission path to the first transmission path second transmission path, in order to transmit data to the relay station in the communication band to which the central control station has been assigned. The relay destination address setting step sets the relay destination address to the address of the relay station, and the reception destination address setting step sets the reception destination address to the address of the second wireless communication apparatus.

Preferably, when the wireless communication control step switches to the second transmission path power transmission path, the data is transmitted directly to the second wireless communication device in the communication band to which the central control station power is already assigned. In the relay destination address setting step, the relay destination address is not set, and in the reception destination address setting step, the reception destination address is set to the address of the second wireless communication apparatus.

Preferably, the wireless communication method requests the central control station to assign a communication band for transmitting data to the second wireless communication apparatus, and whether the central control station communication band is assigned or not. The wireless communication system further includes a vacant band confirmation step of confirming whether there is a vacant communication band in the wireless communication system to which the first wireless communication apparatus currently belongs.

Preferably, the free band confirmation step requests the central control station to provide a communication band to which the communication band desired to be newly assigned is added to the communication band already assigned from the central control station. Control station power Whether or not there is a vacant communication band in the wireless communication system to which the first wireless communication apparatus currently belongs is confirmed depending on whether the communication band is given or not.

[0052] Preferably, in the free band confirmation step, it is assumed that data transmission for the communication band is newly given, and the central control station requests the provision of the communication band from the central control station. Whether or not there is a vacant communication band in the wireless communication system to which the first wireless communication apparatus currently belongs is checked depending on whether or not it is assigned.

Preferably, the wireless communication method further includes the step of stopping switching of the transmission line between the first transmission line and the second transmission line when the empty band confirmation step confirms the shortage of the empty band. Prepare.

A wireless communication system according to another aspect of the present invention includes a first wireless communication device, and a second wireless communication device connected to the first wireless communication device via a network link. The first wireless communication apparatus is provided to a transmission line from a transmission / reception unit that transmits / receives data to / from the second wireless communication apparatus via a plurality of transmission paths, and from a central control station that assigns and releases communication bands, The communication bandwidth is assigned as the communication bandwidth,!, As the communication bandwidth of other transmission paths And a communication band control unit configured to control the communication band to be used.

A wireless communication system according to another aspect of the present invention includes a first wireless communication device, and a second wireless communication device connected to the first wireless communication device via a network link. The first wireless communication apparatus receives data from the wireless communication apparatus on the transmitting side via the transmission line, and transmits the received data to the wireless communication apparatus on the receiving side via the transmission line as wireless communication as a relay station It is an apparatus. The first wireless communication apparatus requests the central control station which assigns and releases the communication band to assign the communication band to the first transmission path to the wireless communication apparatus on the receiving side. Communication device power When instructed, the other band assignment request control unit that requests the central control station to assign the communication band of the first transmission path, and data indicating that the communication band is assigned to the first transmission path. And an attached data transmission control unit that controls transmission of the

According to another aspect of the present invention, there is provided a program product for causing a computer to function as a wireless communication device. This program product performs the steps of transmitting and receiving data to and from the other wireless communication device via a plurality of transmission paths, and a central control station that assigns and opens a communication band to a computer. The step of controlling the communication band so as to use the communication band as the communication band of the other transmission path is performed.

According to another aspect of the present invention, there is provided a program product for causing a computer to function as a wireless communication device. The wireless communication device is a wireless communication device as a relay station that receives data from the wireless communication device on the transmitting side via the transmission path and transmits the received data to the wireless communication device on the receiving side via the transmission path. . Does the program product send the wireless communication device on the transmitting side to request the computer to give the communication band to the first transmission path to the wireless communication device on the receiving side to the central control station to assign and release the communication band? And a step of requesting the central control station to assign the communication band of the first transmission path, and a step of controlling transmission of data indicating that the communication band is assigned to the first transmission path. Run

A storage medium according to still another aspect of the present invention stores any of the program products described above. Brief description of the drawings

FIG. 1 is a block diagram schematically showing a wireless communication system according to an embodiment of the present invention.

FIG. 2 is a functional block diagram showing a schematic configuration of a transmitting station according to an embodiment of the present invention.

FIG. 3 is a functional block diagram showing a schematic configuration of a wireless communication apparatus as a relay station for relaying data transmitted from a transmitting station to a receiving station according to an embodiment of the present invention.

[FIG. 4] A diagram showing an application state of a communication band before the transmission line is switched according to the first embodiment of the present invention, and a transmission line according to the second embodiment of the present invention. It is a figure showing the provision state of the communication band after being

[FIG. 5] A diagram showing a state of provision of a communication band of a transmission path in the middle of switching (part 1).

[FIG. 6] A second diagram showing the state of provision of the communication band of the transmission path in the middle of switching.

[FIG. 7] A diagram showing an application state of a communication band after a transmission path is switched according to the first embodiment of the present invention, and a transmission path according to the second embodiment of the present invention is switched FIG. 7 is a diagram showing the state of provision of communication bands before being

FIG. 8 is a flowchart showing processing executed when the transmitting station switches the transmission path used to transmit data to the receiving station from the first transmission path (Direct link) to the second transmission path.

FIG. 9A is a diagram showing a transmission data sequence.

FIG. 9B is a diagram showing a data frame when transmitting station 102 relays QAP 101 (relay station) to transmit data to receiving station 103.

FIG. 9C is a diagram showing a data frame when the transmitting station 102 directly transmits data to the receiving station 103.

[FIG. 10] A diagram showing how a transmitting station transmits data to a receiving station via QAP by utilizing diversion of the communication band of the first transmission line (Directlink).

FIG. 11 is a diagram (part 1) illustrating the application state of the communication band of the transmission path during switching in the second embodiment of the present invention.

FIG. 12 is a diagram (part 2) illustrating the application state of the communication band of the transmission path during switching in the second embodiment of the present invention.

[FIG. 13] A flowchart showing processing executed when the transmitting station switches the transmission path used when transmitting data to the receiving station to the second transmission path first transmission path (Directlink). Ru.

FIG. 14 is a block diagram showing a hardware configuration of a computer system.

Explanation of sign

100 wireless communication system, 101 QAP, 102 transmitting station, 103 receiving station, 104 first transmission path (Directlink), 105 second transmission path, 106 transmission path (Uplink), 107 transmission path (Dow nlink), 201 CPU, 202 MEM, 203 Transmission Data Browser, 204 Reception Data Browser, 205 Radio Communication Control Unit, 206 Modulation / Demodulation Unit, 207 Antenna, 208 Communication Band Control Unit, 209 Self Band Addition, Release Request Unit, 210 Free Band Confirmation Unit , 211 Other band addition · release request instruction unit, 212 relay destination address setting unit, 213 reception destination address setting unit, 214 user notification unit, 300 relay station, 301 CPU, 302 MEM, 303 transmission data buffer, 304 reception data buffer , 305 wireless communication control unit, 306 modulation / demodulation unit, 307 antenna, 308 communication band control unit, 309 own band assignment / release request unit, 310 other bandwidth assignment / release request control unit, a first transmission path (Dire _C tlink) The band secured on the 104, b transmission line (Downlink) on 107 The reserved band in c, the area reserved on the transmission line (Uplink) 106.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. Their names and functions are also the same

. Therefore, detailed description about them will not be repeated.

First Embodiment

FIG. 1 is a block diagram schematically showing a wireless communication system 100. As shown in FIG. The wireless communication system 100 includes at least a wireless communication device (hereinafter, also simply referred to as “central control station” or “QAP”) 101 as a central control station (QAP) and a wireless communication device as a transmission station (hereinafter simply referred to as “transmission station 102) and a wireless communication device as a receiving station (hereinafter, also simply referred to as “receiving station”) 10

Including 3

When the wireless communication system 100 is installed in a home or the like, a video deck, a DVD player, or the like can be considered as the transmitting station 102. Further, as the receiving station 103, a television or the like can be considered. The transmitter station 102 is built into the VCR or DVD player, etc. It may be connected to a VCR or a DVD player via an interface unit. The receiving station 103 may be one incorporated in a television or the like, or may be connected to the television or the like via an interface unit.

The wireless communication system 100 is not limited to one installed in a home or the like. For example, the wireless communication system 100 may be installed in an office, and the installation location is not particularly limited.

In the transmission path from the transmitting station 102 to the receiving station 103, the “first transmission path (Directlink) 104 from the transmitting station 102 to the receiving station 103” and the relay system from the transmitting station 102 to the wireless communication system 100 are connected. There is a “second transmission path 105” that reaches the receiving station 103 via a wireless communication apparatus as a station (in the present embodiment, the QAP 101 doubles as a relay station).

In the case of the present embodiment, second transmission path 105 includes transmission path 106 from transmitting station 102 to QAP 101 and transmission path 107 from QAP 101 to the receiving station. As described above, in the present embodiment (and the second embodiment described later), since the QAP 101 also serves as a relay station, the transmission path 106 is Uplink and the transmission path 107 is Downlink in the following. It is described as.

The QAP 101 controls assignment and release of a communication band in the wireless communication system 100. When transmitting data to the receiving station 103, the transmitting station 102 designates a transmission path, and requests the QAP 101 to assign a necessary communication band according to the data transmitted. The QAP 101 assigns a communication band to the transmitting station 102 if a free communication band corresponding to the communication band requested from the transmitting station 102 remains in the wireless communication system 100. The transmitting station 102 transmits data to the receiving station 103 using a transmission path designated in advance in the communication band given by the QAP 101.

The transmitting station 102 switches the first transmission path (Directlink) 104 and the second transmission path 105 according to the communication status with the receiving station 103, and transmits data to the receiving station 103. For example, when switching the transmission path from the first transmission path (Directlink) 104 to the second transmission path 105, the transmitting station 102 uses the first transmission path (before switching) in order to avoid a period in which no communication band is secured. It is necessary to secure the communication bandwidth of the second transmission path 105 after switching while securing the communication bandwidth of Directlink 104. This method will be described in detail later. For example, when the error rate exceeds a certain threshold, the transmitting station 102 determines that the communication status with the receiving station 103 is poor, and the transmission path is transmitted from the first transmission path (Directlink) 104 to the second transmission path (Directlink) 104. It may be switched to the transmission path 105. For example, the transmitting station 102 may calculate the number of data transmitted to the receiving station 103 and the number of response data returned when the receiving station 103 has successfully received the data transmitted from the transmitting station 102. Record to the transmitting station 102. Then, the transmitting station 102 also calculates an error rate of, for example, the formula “1 (number of response data Z: number of transmitted data)”.

In addition, when the transmitting station 102 receives, for example, an instruction to switch the transmission path from the receiving station 103, the transmitting station 102 switches the transmission path from the first transmission path (Directlink) 104 to the second transmission path 105. It is also good. When the DVD player, which is the transmitting station 102, and the television, which is the receiving station 103, perform direct communication using the first transmission path (Directlink) 104, it is generally an error if the television moves away from the DVD player. The rate is increasing and television video and audio are disturbed. At this time, for example, the viewer of the television instructs the television to switch the transmission path using a remote control or the like. The television which is the receiving station 103 which has received this instruction instructs the DVD player which is the transmitting station 102 to switch the transmission path.

Next, referring to FIG. 2 to FIG. 10, when the transmission path is switched from first transmission path (Directlink) 104 to second transmission path 105, the transmission path is maintained without impairing the real time property of data transmission. I will explain how to switch between.

FIG. 2 is a functional block diagram showing a schematic configuration of the transmitting station 102. As shown in FIG. Transmitter station 102 is a CPU

(Central Processing Unit) 201, MEM (Memory) 202, transmission data buffer 203, reception data buffer 204, wireless communication control unit 205, modulation / demodulation unit 206, antenna 207, communication band control unit 208, and user notification unit 214.

The CPU 201 is a device that performs processing such as input / output of data of the transmission station 102 and execution of an instruction. The MEM 202 is a main storage device. The MEM 202 can be directly accessed by the CPU 201. The CPU 201 and the MEM 202 are connected to the wireless communication control unit 205 via a system bus.

The transmission data buffer 203 is a device for temporarily storing data to be transmitted to the receiving station 103 or the like. A wireless communication control unit 205 controls transmission and reception of data including a beacon. The wireless communication control unit 205 is connected to the CPU 201 and the MEM 202 as described above. In addition, the transmission data buffer 203, the reception data buffer 204, the modem unit 206, and the communication band control unit 208 are also connected.

Data temporarily stored in the transmission data buffer 203 is transmitted to the radio communication control unit 205. The wireless communication control unit 205 adds a relay destination address for specifying a relay station for relaying data to the data received from the transmission data buffer 203 by using the relay destination address setting unit 212 to specify a receiving station. The receiver address is added by the receiver address setting unit 213 and transmitted to the modem unit 206. The relay destination address and the reception destination address added to the data by the wireless communication control unit 205 will be described in detail later. The modulation / modulation unit 206 modulates the data received from the wireless communication control unit 205, and transmits the modulated data to the receiving station 103 or the like via the antenna 207.

Also, the modulation / demodulation unit 206 receives the modulated data to which the receiving station 103 is also transmitted via the antenna 207. The modem unit 206 demodulates the received modulated data, and then transmits the data to the wireless communication control unit 205.

The wireless communication control unit 205 transmits, to the reception data buffer 204, the data that has also received the reception station 103 equal power. The reception data buffer 204 temporarily stores data received from the wireless communication control unit 205. The data temporarily stored in the reception data buffer 204 is sent to a processing unit (not shown) that processes the received data according to a predetermined procedure.

When the communication band control unit 208 switches the transmission path used to transmit data to the receiving station 103 or the like between the first transmission path (Directlink) 104 and the second transmission path 105, the communication band control section 208 determines the communication band. Control of The communication band control unit 208 includes a self bandwidth assignment / release request unit 209, an available bandwidth confirmation unit 210, and another bandwidth grant / release request instruction unit 211.

[0079] When the transmitting station 102 transmits data, the own band addition 'release request unit 209 requests the QAP 101 to provide a communication band according to the transmitted data. The QAP 101 assigns a communication band if the wireless communication system 100 has a vacant communication band remaining in accordance with the communication band requested by the own band assignment / release request unit 209. The transmitting station 102 transmits data using the transmission path (Uplink) 106 in the QAP 101 power transmission path (Directlink) 104 in the communication band given power. In addition, the own band provision 'release request unit 209 requests the QAP 101 to release the communication band, which has been granted from the QAP 101. When the communication band of the first transmission path (Directlink) 104 or the transmission path (Uplink) 106 is released, the transmitting station 102 can not transmit data using the transmission path whose communication band is released.

The vacant band check unit 210 requests the QAP 101 to assign a communication band according to the data to be transmitted, and the wireless communication system 100 is vacant depending on whether the requested communication band is given by the QAP 101 or not. Check if there is a communication band. The free band check unit 210 will be described in detail later.

Other band addition / release request instruction unit 211 requests QAP 101 to provide a communication band to transmission line (Downlink) 107 or to release the communication band from transmission line (Downlink) 107, for example. (In the first embodiment, since the QAP 101 doubles as a relay station, it instructs the QAP 101). For example, when the transmitting station 102 tries to transmit data to the receiving station 103 using the second transmission path 105, the QAP 101 is requested to assign a communication band to the transmission path (Downlink) 107. Instruct the relay station.

The user notification unit 214 notifies the user of the switching status of the communication band. The user notification unit 214 notifies, for example, the user that the switching of the communication band is completed, the cause of the non-switching, and the like.

FIG. 3 is a functional block diagram showing a schematic configuration of wireless communication apparatus 300 as a relay station that relays data transmitted from transmitting station 102 to receiving station 103. The relay station 300 includes a CPU 301, a MEM 302, a transmission data buffer 303, a reception data buffer 304, a wireless communication control unit 305, a modulation / demodulation unit 306, an antenna 307, and a communication band control unit 308. The descriptions other than the communication band control unit 308 overlap with the description of the transmitting station 102, and therefore, the descriptions thereof will not be repeated here. The communication band control unit 308 includes an own band assignment / release request unit 309 and another band assignment / release request control unit 310.

[0085] When the relay station 300 tries to transmit data, the own band addition 'release request unit 309 adds a communication band according to the data desired to be transmitted, and releases the communication band allocated from the QAP 101. Request the QAP101. Own band granting 'release request part 309 Since the function is the same as the function of the own band provision / release request unit 209 of the transmitting station 102, the description will not be repeated here.

Other band addition / release request control unit 310 requests, for example, to assign a communication band to transmission path (Downlink) 107 to QAP 101 or to release the communication standby of transmission path (Downlink) 107. If the transmission station 102 is instructed by the other band addition / release request instruction unit 211 of the transmission station 102, a communication band is provided to the transmission path (Downlink) 107 to the QAP 101, or Request to release bandwidth.

When a communication band is assigned to the transmission line (Downlink) 107 or when the communication band of the transmission line (Downlink) 107 is released, the relay station 300 (in the case of the first embodiment Q AP 101 ) Data indicating that fact is transmitted to the transmitting station 102. Data indicating that the communication band has been assigned to the transmission line (Down link) 107 or that the communication band of the transmission line (Downlink) 107 has been released is transmitted to the relay station 102 and the transmitting station 102. For example, the signal may be transmitted from the receiving station 103 to the transmitting station 102.

In the first embodiment (see FIG. 1), since the QAP 101 doubles as the relay station 300, the QAP 101 performs the processing of the above-mentioned own band provision 'release request unit 309 and the provision of other bands. · The processing of the release request control unit 310 is performed in its own device. Note that although the communication band control unit 308 of the relay station 300 shows an example in which the free band confirmation unit 210 shown in FIG. 2 is not provided, a free band confirmation unit may be provided.

As described above, in this embodiment, since QAP 101 also serves as relay station 300, QAP 101 includes communication band control section 308 of relay station 300. Also, since the receiving station 103 does not need any special function etc. for the present invention, the detailed description will not be described here.

4 to 7 show the transmission paths used when the transmitting station 102 switches data from the first transmission path (Directlink) 104 to the second transmission path 105 when transmitting data to the receiving station 103. It is a figure showing the granting state of a communication band. The assigned state indicates to which transmission path a communication band is assigned.

FIG. 4 shows an application state before the transmission path is switched. That is, FIG. 4 shows that the communication band is assigned to the first transmission path (Directlink) 104. Figure 5 And FIG. 6 is a figure showing the provision state of the communication band of the transmission line in the middle of switching. FIG. 7 is a diagram showing the state after the transmission path is switched. That is, FIG. 7 shows that the communication band is assigned to the second transmission path 105.

[0092] FIG. 8 shows a process that is executed when the transmitting station 102 switches the transmission path used to transmit data to the receiving station 103 from the first transmission path (Directlink) 104 to the second transmission path 105. It is a flowchart. Among the processes executed by the transmitting station 102, the processes up to the transmission of data use conventional techniques and can be easily understood by those skilled in the art. Therefore, the description of the process is not described here. Further, in the first embodiment, the case where the transmission line is switched from the first transmission line (Directlink) 104 to the second transmission line 105 will be described. Therefore, at the start of the flowchart shown in FIG. It is assumed that the communication band has already been assigned to the Directlink 104 from the QAP 101 (the state of FIG. 4).

First, in step S 401, the available bandwidth checking unit 210 uses the transmission link (Downlink) 107 as a communication link necessary for transmitting data to the wireless communication system 100. Check if there are any excesses. Here, first of all, the reason for checking whether or not the idle communication band corresponding to the communication band necessary for transmitting data using the transmission line (Downlink) 107 is sufficient is as follows.

If a communication band is assigned to first transmission path (Directlink) 104 and transmission path (Downlink) 107 from QAP 101 (the state in FIG. 5), transmitting station 102 performs transmission without a communication band. By using the communication band of the first transmission path (Di rectlink) 104, which already has a communication band already assigned as the communication band of the path (Uplink) 106, data is received by the receiving station 103 using the second transmission path 105. Can be sent. The use of the communication band of a certain transmission line as the communication band of another transmission line will be described in detail later.

Here, a method will be specifically described in which the free band checking unit 210 checks whether or not there is a free communication band remaining in the wireless communication system 100. For example, it is assumed that the amount of communication bandwidth required to transmit data using the transmission line (Downlink) 107 is "OC".

For example, free bandwidth check unit 210 adds the communication bandwidth amount “α” desired to be newly assigned to the communication bandwidth of first transmission path (Directlink) 104 already assigned from QAP 101. Request QAPIOI to assign communication bandwidth (boost!). If the wireless communication system 100 has an idle communication band corresponding to the requested communication band, the QAP 101 assigns a communication band, but does not grant a communication band. Therefore, if the communication band is assigned from the QAP 101, the free band confirmation unit 210 can confirm that the free communication band for the communication band amount "ひ" remains in the wireless communication system 100. After confirming that the free communication band remains in the wireless communication system 100, the free band confirmation unit 210 executes processing for returning the communication band of the first transmission path (Directlink) 104 to the original communication band.

Further, as another method, for example, it is assumed that the available bandwidth check unit 210 transmits data corresponding to the communication bandwidth “α” desired to be assigned to the QAP, and adds the communication bandwidth “α”. Request to QAP101. In this case, the free band confirmation unit 210 transmits the communication band amount to the first transmission path (Dire ctlink) 104 in addition to the communication band of the first transmission path (Directlink) 104 already assigned from the QAP 101. Request QAPIOI to give "a". Also, as another method, the available bandwidth check unit 210 further transmits the communication bandwidth amount to the transmission channel (Uplink) 106 separately from the communication bandwidth of the first transmission channel (Di rectlink) 104 already assigned from the QAP 101. You may request QAPIOI to give "a". Also, as another method, the free band confirmation unit 210 may be configured to use another wireless communication equipment other than the QAP 101 and the receiving station 103 separately from the communication band of the first transmission path (Directlink) 104 already assigned from the QAP 101. Alternatively, the QAP 101 may be required to provide the communication bandwidth "a" to the transmission path for transmitting data. If the communication bandwidth is provided from the QAP 101, the available bandwidth confirmation unit 210 can confirm that the wireless communication system 100 has an available communication bandwidth remaining for the communication bandwidth amount “ひ”. After confirming that there are free communication bands remaining in the wireless communication system 100, the free band confirmation unit 210 executes processing for releasing the secured communication band amount “O”.

Furthermore, more preferably, for example, the other band addition · release request instruction unit 211 of the transmission station 102 is transmitted to the QAP 101 other band provision · release request control unit 310 as the transmission path (Downlink) 107 communication bandwidth amount “ It may be required to give "H". In this case, the transmitting station 102 receives data indicating that the communication band has been assigned from the other band assignment / release request control unit 310. Then, it is possible to confirm that there are remaining free communication bands V corresponding to the communication band requested to the wireless communication system 100, and omit processing (step S403) for securing communication bands described later. Can.

In step S 402, when it is confirmed by the free band confirmation unit 210 that there is no free communication band remaining in the wireless communication system 100, this flowchart ends. In this case, the communication band control unit 208 of the transmitting station 102 ends the process for switching the transmission path from the first transmission path (Directlink) 104 to the second transmission path 105. Even in this case, since the communication band is assigned to the first transmission path (Directlink) 104 (the state shown in FIG. 4), the transmission station 102 Data transmission to the receiving station 103 can be continued using the first transmission path (Directlink) 104. After a certain time, the initial force in Fig. 8 may be started again. Also, the user may be notified that the transmission path has been switched to the first transmission path (Directlink) 104 and the second transmission path 105 as well. Also, preferably, the user may be notified of a message such as "insufficient bandwidth" or "Please move to a better location". On the other hand, when it is confirmed in step S402 that the free band confirmation unit 210 has left the free communication band in the wireless communication system 100, the process proceeds to step S403.

In step S 403, the other band addition / release request instruction unit 211 requests the QAP 101 to provide the communication band to the transmission path (Downlink) 107 in the other band addition / release request control unit 310. In step S404, the communication band control unit 208 confirms whether or not the data indicating that the communication band has been assigned to the transmission path (Downlink) 107 transmitted from the QAP 101 is received.

If it is confirmed in step S 404 that data indicating that the communication band has been assigned to the transmission path (Downlink) 107 transmitted from the QAP 101 is received and this is false, this flowchart ends. . For example, while the processing in step S401 is performed until the processing in step S403 is performed, the wireless communication system 100 runs out of available communication bandwidth because another wireless communication device secures the communication bandwidth. In the case, etc., data indicating that the communication band has been assigned from the QAP 101 to the transmission line (Downlink) 107 is not transmitted. In this case, the communication band control unit 208 of the transmitting station 102 gives up switching to switch the transmission path from the first transmission path (Direct Link) 104 to the second transmission path 105. Even in this case, since the communication band is assigned to the first transmission path (Directlink) 104 in the communication band assignment state of the transmission path (the state shown in FIG. 4), the transmitting station 102 The transmission line (Directlink) 104 can be used to continue transmitting data to the receiving station 103. At this time as well, after a certain period of time, the initial force in Fig. 8 may be started again. Also, the user notification unit 214 may notify the user notification unit that the transmission path has not been switched from the first transmission path (Directlink) 104 to the second transmission path 105. In this case, the user notification unit 214 may notify the user of a message such as “the bandwidth was not assigned”.

On the other hand, when it is confirmed in step S 404 that the communication band control unit 208 has received data indicating that the communication band has been assigned to the transmission path (Downlink) 107 transmitted from the QAP 101, the process is The process proceeds to step S405.

At this point in time, the communication band of the transmission path is assigned the communication band of the first transmission path (Directlink) 104 and the transmission path (Downlink) 107 (state in FIG. 5). is there . In step S405, the communication band of the first transmission path (Directlink) 104 is used as the communication band of the transmission path (Uplink) 106 to which the communication band is not assigned. As a result, the transmitting station 102 can transmit data to the receiving station 103 using the second transmission path 105.

Here, a process of using the communication band of the first transmission path (Directlink) 104 as the communication band of the transmission path (Uplink) 106 to which the communication band is not assigned will be described. According to the specifications of IEEE802.IE, the communication band control unit 208 of the transmitting station 102 requests the QAP 101 to assign a communication band to a transmission path by transmitting data transmitted using a certain transmission path. In addition to the statistical information (TSPEC), it is necessary to send to the QAP 101 information specifying a transmission path (a first transmission path (Di rectlink) 104, a transmission path (Uplink) 106, etc.) viewed from the transmitting station 102. However, QAP 101 transmits time to transmit data sequence (identified by TID) in Poll frame (for granting communication right) to transmit to transmitting station 102 when granting communication band. Include parameters related to (communication band) but do not include parameters that limit the transmission path. Therefore, in terms of specifications, the transmitting station 102 has a free transmission path. It is possible to transmit a transmission data sequence with a TID specified by the time (communication band) for which transmission is permitted.

As the communication band of the transmission line (Uplink) 106 to which no communication band is assigned, the first transmission line

In order to transmit data to the receiving station 103 using the second transmission path 105 using the (Directlink) 104 communication band, as described above, the radio communication control unit 205 of the transmitting station 102 It is necessary to change and set the relay destination address for specifying the relay station that relays the data and the receiver address for specifying the receiving station.

An example of a transmission data sequence and a data frame will be described with reference to FIGS. 9A to 9C. FIG. 9A is a diagram showing a transmission data sequence. FIG. 9B is a diagram showing a data frame when the transmitting station 102 relays the QAP 101 (relay station) and transmits data to the receiving station 103. FIG. 9C is a diagram showing a data frame when the transmitting station 102 transmits data directly to the receiving station 103. As shown in FIG.

As shown in FIG. 9B, a data frame includes a Frame—Control field 501, a Duration / lD field 502, a MAC address specification unit (“Addressl field 503” to “Address 4 Finoredo 507”), Sequence—Control The Fino Red 506, the QoS—Control field 508, the transmission data 509, the FCS (Frame Check Sequence) field 510, and the like are included.

Frame—Control field 501 has a role of identifying the type of frame and the like.

The DurationZlD field 502 indicates the time required to transmit the transmit data sequence. Sequence—Control field 506 contains a sequence number. The QoS-Control field 508 indicates a TID and a communication permission time etc. when the data frame is a Poll frame, and indicates a communication time or data size etc. required next when the data frame is a QoS-Null frame etc. .

The relay destination address setting unit 212 and the reception address setting unit 213 in the wireless communication control unit 205 of the transmitting station 102 receive “Datal” which is a part of the transmission data sequence via the QAP 101 as the receiving station 103 If you want to transmit to the network, the MAC address designating unit 1 (Addressl field 503) of the data frame should be BSSID (a wireless communication network in which the QAP 101 forms) so that the relay station address is the address of QAP 101 and the address of Know Set to different ID). The relay destination address setting unit 212 and the reception destination address setting unit 213 include the MAC address specification unit 2 (Address 2 field 504), the MAC address of the transmitting station 102, the MAC address specification unit 3 (Address 3 field 505), and the MAC address of the reception station 103. Set the address and MAC address specification part 4 (Address 4 field 507) to none (NZA).

On the other hand, relay destination address setting unit 212 and reception destination address setting unit 213 in wireless communication control unit 205 of transmitting station 102 directly transmit “Data 2”, which is a part of the transmission data sequence, to receiving station 103. If you want to transmit, do not set the relay station address and set the MAC address specification part 1 (Address 1 field 50 3) of the data frame to the MAC address of the receiving station 103 so that the receiving address becomes the receiving station 103. . The relay destination address setting unit 212 and the reception destination address setting unit 213 are the MAC address of the transmitting station 102 (MAC address designation unit 2 (Address 2 field 504)), the MAC address designation unit 3 (Address 3 field 505) of the BSSI D, Set MAC address specification part 4 (Address 4 field 507) to none (NZA).

By doing this, if the communication band is assigned to the first transmission path (Directlink) 104 and the transmission path (Do wnlink) 107, the transmission path (Uplink) to which the communication band is not assigned is obtained. The communication band of the first transmission path (Directlink) 104 can be used as the communication band of the transmission station 102, and the transmitting station 102 can transmit data to the receiving station 103 using the second transmission path 105.

Similarly, if the communication band is assigned to the transmission path (Uplink) 106, the communication band is assigned, and the transmission path (Uplink) is used as the communication band for the first transmission path (Directlink) 104. A communication band of 106 can be used, and the transmitting station 102 can transmit data to the receiving station 103 using the first transmission path (Directlink) 104.

Referring again to FIG. 4, in step S 405, communication band control unit 208 uses the communication band of first transmission path (Directlink) 104 for transmission path (Uplink) 106 to which no communication band is assigned. Perform the process. By this, the transmitting station 102 can transmit data to the receiving station 103 using the second transmission path 105. The communication band control unit 208 stops the process of using the communication band of the first transmission line (Directlink) 104 as the communication band of the transmission line (Uplink) 106. In this case, the transmitting station 102 can transmit data to the receiving station 103 by using the first transmission path (Directlink) 104.

However, although the transmission station 102 is required to give a communication band to the first transmission path (Directlink) 104 and the communication station 102 gives the communication band to the transmission station 102, the transmission station 102 still receives the communication band. Since it is used as a communication band of the transmission line (Uplink) 106, as a result, a time during which data is not transmitted using the first transmission line (Directlink) 104 occurs. Therefore, the QAP 101 releases the communication band assigned to the first transmission path (Directlink) 104 if it is determined that the time has exceeded a predetermined time in the IEEE 802. 1 specification.

Therefore, in step S405, the communication band control unit 208 of the transmitting station 102 transmits the first transmission path (Directlin k) at the end of the time (communication band) for which transmission by the QAP 101 is permitted (communication band). A QoS-Null frame indicating that data has been sent to the receiving station 103 using 104 is sent to the Q AP 101. By doing this, the QAP 101 determines that the transmitting station 102 is transmitting data to the receiving station 103 using the first transmission path (Direct link) 104, and the communication band of the first transmission path (Direc link) 104. Do not open

Similarly, when using the communication band of the transmission line (Uplink) 106 as the communication band of the first transmission line (Directlink) 104 to which the communication band is not assigned, the communication band control of the transmitting station 102 is also performed. The unit 208 transmits, to the QAP 101, a QoS-Null frame indicating that data has been transmitted using the transmission path (Uplink) 106 at the end of the time (communication band) for which transmission is permitted by the QAP 101. By doing this, the QAP 101 determines that the transmitting station 102 is transmitting data using the transmission line (Uplink) 106, and does not release the communication band of the transmission line (Uplink) 106.

[0118] FIG. 10 is a diagram showing a state where the transmitting station 102 transmits data to the receiving station 103 via the QAP 101 by using the communication band of the first transmission path (Directlink) 104. It is assumed that the communication band is already assigned from the QAP 101 to the first transmission path (Directlink) 104. The transmitting station 102 can transmit data to the receiving station 103 using the first transmission path (Directlink) 104 in the communication band provided by the QAP 101.

When the wireless communication control unit 205 of the transmitting station 102 uses the communication band of the first transmission line (Directlink) 104 as the communication band of the transmission line (Uplink) 106 to which the communication band is not assigned, As described above, processing is performed to change and set the MAC address designation unit ("Address 1 field 503" to "Address 4 field 507") in the MAC header of the data frame. As a result, the transmitting station 102 can transmit data to the receiving station 103 using the second transmission path 105. At this time, the QAP 101 that received the data transmitted from the transmitting station 102 receives the received data because the destination of the data is described as the receiving station 103 in the addressing section (Address 3) in the MAC header. Transfer to receiving station 103.

[0120] Communication band control section 208 of transmitting station 102 determines the time at which transmission is permitted by QAP 101 (communication band, so that the communication band of first transmission path (Directlink) 104 is not released by QAP 101 (communication band). At the end of), a QoS-Null frame indicating that data has been sent to the receiving station 103 using the first transmission path (Directlink) 104 is sent to the QAP 101.

Note that using the communication band for a certain transmission line as the communication band for another transmission line can be used only when the transmission line is switched from the first transmission line (Directlink) 104 to the second transmission line 105. It is also useful when the communication bands of the transmission line (Directlink) 104 and the second transmission line 105 need to be provided together. Because, if the communication band of either the first transmission path (Directlink) 104 or the transmission path (Uplink) 106 and the communication band of the transmission path (Downlink) 10 7 are given, the first transmission path (Directlink) The reason is that the communication band amount of 104 and the second transmission path 105 can be obtained with the communication band amount which is equivalent to the effect obtained by both of them.

Refer back to FIG. Each process up to step S405 switches the transmission path from the first transmission path (Directlink) 104 to the second transmission path 105 without causing a period in which no communication band is assigned and without impairing the real time property of data transmission. be able to. However, if the wireless communication system 100 has an idle communication band which can add a communication band to the transmission line (Uplink) 106, the communication band should be added to the transmission line (Uplink) 106 to the Q AP 101. It is preferable to request. Because the communication band of the second transmission path 105 is assigned, the communication band control unit 208 of the transmitting station 102 continues to use the communication band of a certain transmission path as the communication band of another transmission path. No longer needed.

In step S406, the own band assignment / release request unit 209 requests the QAP 101 to assign a communication band to the transmission path (Uplink) 106. QAP101, own band grant 'release request If a free communication band corresponding to the communication band requested from unit 209 is left in wireless communication system 100, the communication band is provided. The state of provision of the communication band of the transmission path at this time is, for example, the state shown in FIG.

If it is determined in step S407 that the own band assignment / release request unit 209 has not applied any communication band to the QAP 101, the process is returned to step S405. On the other hand, when the own band assignment / release request unit 209 determines in step S407 that the communication band has been granted from the QAP 101, the process proceeds to step S408. In step S408, the self-band allocation 'release request unit 209 requests the QAP 101 to release the communication band of the first transmission path (Directlink) 104. The assigned state of the communication band of the transmission path at this time is, for example, as shown in FIG. Thereafter, the flowchart ends. At this time, the user notification unit 214 may notify the user that the transmission path has been switched from the first transmission path (Directlink) 104 to the second transmission path 105.

In step S408, an example is shown in which the own band provision / release request unit 209 requests the QAP 101 to release the communication band of the first transmission path (Directlink) 104. The request unit 209 may not request the QAP 101 to open the communication band of the first transmission path (Directlink) 104.

In the present embodiment, wireless communication system 100 has only one transmitting station 102, and the transmission path from transmitting station 102 to receiving station 103 is the first transmission path (Directlink) and the second transmission. An example is shown in which the transmitting station 102 switches the transmission line when there are two ways with the line 105, and an example in which the bandwidth of the amount transmission line can be secured with a small amount of bandwidth is shown. However, the system to which the present invention is applied is not limited to this. For example, the present invention is applicable even when the wireless communication system 100 has a plurality of wireless communication devices and the transmitting station can select three or more transmission paths. In this case, for example, the transmitting station may switch the transmission line, or the transmission station may be able to secure a plurality of transmission line bands with a small amount of band.

According to the first embodiment, when the transmitting station 102 switches the transmission path from the first transmission path (Directlink) 104 to the second transmission path 105, the transmitting station 102 transmits the transmission path to the first transmission path (Directlink) 104. By using the assigned communication band as the communication band of the transmission line (Uplink) 106, data can be transmitted to the receiving station 103 using the second transmission line 105 after switching. Also, The transmitting station 102 only uses the communication band assigned to the first transmission path (Directlink) 104 for the transmission path (Uplink) 106 after switching, so the first transmission path (Dir ectlink) before switching is used. Data can be sent to the receiving station 103 using 104. That is, the transmitting station 102 can return to the communication state before switching at any time during the switching process of the transmission path.

In addition, when the transmitting station 102 switches the transmission path from the first transmission path (Directlink) 104 to the second transmission path 105, the switching causes a period in which no communication band is assigned to the transmission path. There is no Therefore, it can be prevented that the real-time property of data transmission is impaired.

Also, before the transmitting station 102 switches the transmission path from the first transmission path (Directlink) 104 to the second transmission path 105, transmission is performed by confirming whether the wireless communication system 100 has a free communication band or not. The station 102 can predict whether it is possible to switch from the first transmission path (Directlink) 104 to the second transmission path 105.

When the transmitting station 102 confirms that the available communication band is insufficient, the transmitting station 102 transmits the transmission path from the first transmission path (Directlink) 104 to the second transmission path 105. It is possible to stop switching to

In addition, the transmitting station 102 transmits the communication band assigned to the first transmission path (Directlink) 104 to the transmission path.

(Uplink) When used as the communication band of 106, QoS indicating that data was transmitted to the receiving station 103 using the first transmission path (Directlink) 104 at the end of the time when transmission is permitted (communication band) -By transmitting a Null frame to the QAP 101, it is possible to prevent the communication band assigned to the first transmission path (Directl ink) 104 from being released by the QAP 101. Also, the transmitting station 102 can notify the user of the status of the process of switching the transmission path from the first transmission path (Directlink) 104 to the second transmission path 105.

In addition, the transmitting station 102 can use the communication band of the first transmission path (Directlink) 104 or the transmission path 106 as the communication band of another transmission path to transmit the first transmission path (Directlink) 104 and the first transmission path (Directlink) 104. The communication band required when securing the communication band for both of the two transmission paths 105 can be reduced. Therefore, efficient operation of the communication band can be performed as the wireless communication system 100. Second Embodiment

Next, a second embodiment of the present invention will be described. In the present embodiment, points different from the first embodiment will be mainly described. Specifically, in the first embodiment, an example in which the transmission path is switched from the first transmission path (Directlink) 104 to the second transmission path 105 and data is transmitted from the transmitting station 102 to the receiving station 103 will be described. It was done. On the other hand, in the present embodiment, an example will be described in which the transmission line is switched from the second transmission line 105 to the first transmission line (Directlink) 104 and data is transmitted from the transmitting station 102 to the receiving station 103.

The hardware configuration of the wireless communication system according to the present embodiment is the same as the hardware configuration of the wireless communication system according to the first embodiment, except for the components described below. Their functions are also the same. Therefore, the explanation about them will not be repeated here.

Also in the present embodiment, the QAP 101 performs a function as a relay station. The second transmission path 105 includes a transmission path 106 from the transmitting station 102 to the QAP 101 and a transmission path 107 from the QAP 101 to the receiving station.

FIG. 11 and FIG. 12 respectively show the state of provision of the communication band of the transmission path in the process of switching in the present embodiment.

FIG. 13 is a flowchart showing processing executed when the transmitting station 102 switches the transmission path used when transmitting data to the receiving station 103 from the second transmission path 105 to the first transmission path (Directlink) 104. It is. By these processes, the assignment state of the communication band of the transmission line shifts from the state shown in FIG. 7 described above to the state shown in FIG. Of the processes executed by the transmitting station 102 similar to the first embodiment described above, the processes up to the transmission of data are realized by the prior art, which can be easily understood by those skilled in the art. It is a thing. Therefore, the description about them will not be repeated here. Further, in the present embodiment, the case where the transmission path is switched from the second transmission path 105 to the first transmission path (Directlink) 104 will be described. Therefore, at the start of the flowchart shown in FIG. 13, it is assumed that the communication band has already been assigned from the QAP 101 to the transmission line (Uplink) 106 and the transmission line (Downlink) 107 (state shown in FIG. 7). ).

The transmitting station 102 transmits the first transmission path (Directlink) 104 according to the communication status with the receiving station 103. The second transmission path 105 is switched to transmit data to the receiving station 103. When the transmitting station 102 switches the transmission path from the second transmission path 105 to the first transmission path (Directlink) 104, a communication band is assigned, so that a period occurs and the real time property of data transmission is not impaired. In order to set the second communication path 105 before the switching, the communication band control unit 208 adds the communication band to the first transmission path (Directlink) 104 after the switching. It is necessary to request QAP101.

For example, when the error rate exceeds a certain threshold, the transmitting station 102 which is the same as that of the first embodiment determines that the communication status with the receiving station 103 is inferior, and the transmission path is transmitted to the second transmission line. The path 105 may be switched to the first transmission path (Directlink) 104. Also, when the television viewer who is the receiving station 103 uses a remote control or the like to instruct the television to switch the transmission path, the transmitting station 102 performs transmission based on the switching instruction relayed by the QAP 101. The path may be switched from the second transmission path 105 to the first transmission path (Directlink) 104.

Referring to FIG. 13, first, in step S 701, free band check unit 210 performs free communication according to the communication band required to transmit data using first transmission path (Directlink) 104. Check if there is any excess bandwidth in the wireless communication system 100.

Here, an outline of a method of checking whether or not the free band checking unit 210 checks whether or not there is a free communication band remaining in the wireless communication system 100 will be described. For example, it is assumed that the communication bandwidth required to transmit data using the first transmission path (Directlink) 104 is "j8". The free band confirmation unit 210 checks whether or not the remaining free communication band exists in the wireless communication system 100 by replacing the communication band amount α with j8 using the method described in the first embodiment.

Furthermore, more preferably, for example, the own band provision 'release request unit 209 of the transmitting station 102 adds the communication bandwidth amount “” to the first transmission path (Directlink) 104 with respect to the QAP 101. You may ask for it. In this case, when the communication band is assigned from the QAP 101, the transmitting station 102 can confirm that there is an idle communication band remaining in accordance with the communication band requested to the wireless communication system 100, and the communication described later. The process for securing the bandwidth (step S703) can be omitted.

In step S 702, free band check unit 210 power is freed to wireless communication system 100. If it is confirmed that the communication band is left, the process proceeds to step S703. In step S 703, the local band provision 'release request unit 209 requests the QAP 101 to provide a communication band to the first transmission path (Directlink) 104. The QAP 101 assigns a communication band if the wireless communication system 100 still has a free communication band corresponding to the communication band requested by the self band assignment / release request unit 209 (state shown in FIG. 6). In this case, for example, another wireless communication device secures a communication band before the processing in step S703 is performed until the processing in step S701 is performed. In such cases, the QAP 101 can not assign a communication band.

If it is determined in step S704 that the own band addition / release request unit 209 has not applied any communication band from the QAP 101, this flowchart ends. In this case, the communication band control unit 208 of the transmission station 102 gives up switching to switch the transmission path from the second transmission path 105 to the first transmission path (Dire ctlink) 104. Even in this case, since the state of the transmission path is the state in which the communication band is assigned to the second transmission path 105 (the state shown in FIG. 7), the transmitting station 102 sets the second transmission path 105 It can continue to be used to transmit data to the receiving station 103. If it is determined in step S704 that the own band addition 'release request unit 209 determines that the communication band is not given from the QAP 101, the process may be advanced to step S706 described later. Also, after a certain time, processing may be started again from the beginning of FIG. In addition, the user notification unit 214 may notify the user that the transmission path has not been switched from the second transmission path 105 to the first transmission path (Directlin k) 104. Preferably, the user notification unit

In the case of 214, the user may be notified of a message such as "insufficient bandwidth" or "Please move to a better location in the radio wave condition".

On the other hand, in step S704, when own band provision / release request unit 209 determines that the communication band is given from QAP 101, the process proceeds to step S705. In step S 705, the self band assignment / release request unit 209 requests the QAP 101 to release the communication band of the transmission line (Uplink) 106. Also, the other band provision / release request instruction unit 211 requests the QAP 101 to release the communication band of the transmission line (Downlink) 107. The other band assignment / release request control unit 310 of QAP 101 includes a transmission line (Uplink) 106 and a transmission line (Downli nk) A process for releasing the communication band of 107 is performed. At this point, the assignment status of the communication band of the transmission line is as shown in FIG. 4, and this flowchart ends.

In step S702, when it is confirmed that the available bandwidth is not left in the wireless communication system 10, the process proceeds to step S706. At this point in time, the communication band of the transmission line (Uplink) 106 and the transmission line (Downlink) 107 is given and passed (the state shown in FIG. 7).

In step S 706, a communication band is assigned !, a process of using the communication band of the transmission line (Uplink) 106 as the communication band of the first transmission line (Directlink) 104 It will be done. Thereby, the transmitting station 102 can transmit data to the receiving station 103 using the first transmission path (Directlink) 104. Also, in step S706, the communication band control unit 208 of the transmitting station 102 controls the transmitting station 102 using the transmission path (Uplink) 106 at the end of the time (communication band) for which transmission is permitted by the QAP 101. A QoS_Null frame is transmitted to the QAP 101, which indicates that the data has been transmitted to 103. By doing this, the QAP 101 determines that the transmitting station 102 is transmitting data to the receiving station 103 using the transmission line (Uplink) 106, and does not release the communication band of the transmission line (Uplink) 106.

By the processing in step S706, a transmission path that does not cause a period in which no communication band is given and does not impair the real-time property of data transmission is a second transmission path 105 to a first transmission path (Directlink). It is switched to 104. If the wireless communication system 100 still has a free communication band which can provide a communication band to the first transmission path (Directlink) 104, the communication band is transmitted to the first transmission path (Directlink) 104. It is preferable to require QAP 101 to grant. Because the communication band of the first transmission path (Directlink) 104 is given, the communication band control unit 208 of the transmitting station 102 uses the communication band of one transmission path described above as the communication band of another transmission path. It is not necessary to continue the process of

In step S 707, the other band provision / release request instruction unit 211 requests the QAP 101 to provide the other bandwidth addition / release request control unit 310 to release the communication band of the transmission path (Downlink) 107. If the communication band of the transmission line (Downlink) 107 has already been released, the process in step S 707 is not performed. In step S 707, the communication band control unit 208 If data indicating that the communication band of the transmission path (Downlink) 107 has been released is received from the QAP 101, the process proceeds to step S708. At this point, the application status of the communication band of the transmission line is as shown in FIG.

[0150] In step S708, the own band assignment 'release request unit 209 requests the QAP 101 to assign a communication band to the first transmission path (Directlink) 104. The QAP 101 assigns the communication band to the first transmission path (Directlink) 104 if the wireless communication system 100 has a remaining free communication band corresponding to the communication band requested from the own band provision 'release request unit 209. . In step S706, since the communication band of the transmission line (Downlink) 107 is released, there is a high possibility that an idle communication band is left in the wireless communication system 100. In step S708, the communication band is easily assigned by the QAP 101. ,.

If it is determined in step S 709 that self-band assignment * release request unit 209 has not applied a communication bandwidth from QAP 101, the process is returned to step S 706. On the other hand, in step S709, when own band allocation 'release request unit 209 determines that the communication band has been allocated by QAP 101, the process proceeds to step S710. At this point, the assignment status of the communication band of the transmission path is as shown in FIG. In step S710, the own band assignment / release request unit 209 requests to release the communication band of the transmission line (Uplink) 106 which has become unnecessary. At this point, the assignment status of the communication band of the transmission line is as shown in FIG. 4, and this flowchart ends. At this time, the user notification unit 214 may notify the user that the transmission path has been switched from the second transmission path 105 to the first transmission path (Directlink) 104.

In the first and second embodiments described above, the communication band of the transmission path after switching is not given because the free communication band of the wireless communication system 100 is insufficient! When, the communication band of the transmission path before switching that has already been assigned from QAP 101 may be released, and data may be transmitted using EDCA on the transmission path before switching. In this way, the shortage of the free communication band of the wireless communication system 100 is eliminated, and it becomes easy to secure the communication band after switching.

Also, in the first and second embodiments described above, the QAP 101 doubles as the role of the relay station 300, and an example is shown. Another wireless communication device operates as the relay station 300. thing It may be

Further, in the first and second embodiments, the communication band control unit 208 of the transmitting station 102 and the communication band control unit 308 of the relay station 300 are requested to release the band of the transmission path, The wireless communication apparatus other than the transmitting station 102 and the relay station 300 which is performing the instruction of the request and the confirmation of the free communication band may perform the processing.

According to the second embodiment, when the transmitting station 102 switches the transmission path from the second transmission path 105 to the first transmission path (Directlink) 104, the transmission station (Uplink) 106 is assigned. By using the communication band as the communication band of the first transmission path (Directlink) 104, data can be transmitted to the receiving station 103 using the first transmission path (Directlink) 104 after switching. In addition, since the transmitting station 102 only uses the communication band assigned to the transmission line (Uplink) 106 as the communication band for the first transmission line (Directlink) 104 after switching, transmission before switching is performed. Data can be transmitted to the receiving station 103 using the Uplink 106 and the Downlink 107. That is, the wireless communication system 100 according to the present embodiment can return to the communication state before switching at any time during the switching process of the transmission path.

Further, when the transmitting station 102 executes a process of switching the transmission line from the second transmission line 105 to the first transmission line (Directlink) 104, no communication band is assigned to the transmission line. There is no period of time. Therefore, it is possible to prevent the loss of real time of data transmission.

Also, before the transmitting station 102 switches from the second transmission path 105 to the first transmission path (Directlink) 104, the free band check unit 210 checks whether there is a free communication band in the wireless communication system 100 or not. . Therefore, the transmitting station 102 can predict whether or not the second transmission path 105 can be switched to the first transmission path (Directlink) 104. When the free band confirmation unit 210 confirms that the free band is insufficient, the transmitting station 102 can stop switching the transmission path from the second transmission path 105 to the first transmission path (Directlink) 104.

When the communication band assigned to the transmission line (Uplink) 106 is used as the communication band for the first transmission line (Directlink) 104, the transmission line is transmitted at the end of the time when transmission is permitted (communication band). QoS_Null indicates that the data has been transmitted to the receiving station 103 using (Uplink) 106 By transmitting the frame to the QAP 101, it is possible to prevent the communication band assigned to the transmission line (Uplink) 106 from being released by the QAP 101.

In addition, the transmitting station 102 can notify the user of the status of the process of switching the transmission path from the second transmission path 105 to the first transmission path (Directlink) 104 by displaying a message or the like. it can.

[0160] Note that the object of the present invention can be achieved by the combination of circuit elements and other components that realize each process, and the object can be achieved by the cooperation of software and hardware. . That is, a storage medium (main storage or external storage, etc.) storing a program code of software for realizing the functions of the first embodiment and the second embodiment described above is used as a wireless communication system or a wireless communication device. The wireless communication system can also be achieved by supplying and executing the program code stored in the storage medium by the computer (CPU or MPU) of the wireless communication device.

Thus, a computer system 1400 that functions as a wireless communication device according to the present embodiment will be described. FIG. 14 is a block diagram showing a hardware configuration of computer system 1400.

Computer system 1400 includes a CPU 1410 mutually connected by a data bus, a mouse 1420 and a keyboard 1430 receiving instructions from a user of computer system 1400, and execution of a program by input data or CPU 1410. RAM 1440 for temporarily storing generated data, a hard disk 1450 capable of storing a large amount of data, a CD-ROM (Compact Disk-Read Only Memory) drive 1460, a monitor 1480, and a communication IF ( Interface) and 1490. The CD-ROM drive 1460 has a CD-ROM 1462 attached.

The processing in computer system 1400 is realized by each hardware and software (program code) executed by CPU 1410. Such software is stored in advance in the RAM 1440 or the hard disk 1450. Also, software may be stored in a CD-ROM 1462 or other data storage medium and distributed as a program product. Alternatively, the software may be downloaded as a program product that can be downloaded by an information provider connected to the Internet or other communication line. It may be provided. Such software is stored on the hard disk 1450 after the data recording medium is read by the CD-ROM drive 1460 or other reader or downloaded via the communication IF 1490. The software is read from hard disk 1450 into RAM 1440 as an executable format, and is executed by CPU 1410.

Each piece of hardware constituting computer system 1400 shown in FIG. 14 is general one. Therefore, it can be said that the most essential part of the present invention is software stored in a RAM 1440, a hard disk 1450, a CD-ROM 1462 or other data recording medium, or downloadable via a network. The operation of each piece of hardware in computer system 1400 is well known, and therefore detailed description will not be repeated.

In this case, the program code itself of the read-out software will realize the functions of the first and second embodiments described above, and the storage medium storing the program code is the present embodiment. It will constitute the invention.

The storage medium for supplying the program code may be a semiconductor memory or other fixed medium for carrying the program. Such media include, in addition to hard disk 1450 and CD-ROM 1462, flexible disk, cassette tape, magneto-optical disk (MO (Magnetic Optical Disc), MD (Mini Disc), DVD), IC card (memory card) Optical card, mask ROM, EPROM (Erasable programmable ROM), EEP ROM (Electrically Erasable and Programmable ROM), flash ROM and the like.

Also, by executing the program code read out by the computer, the functions in the respective embodiments are only realized, and based on the instruction of the program code, the operating system (Operating System (Operating System) is executed on the computer). ) The function of each embodiment may be realized by executing part or all of the actual processing and the execution of the processing.

Furthermore, the program code of which the storage medium power is also read out is written in the memory provided in the function expansion board inserted in the computer or the function expansion unit connected to the computer, and based on the instruction of the program code, The CPU in the function expansion board or function expansion unit performs part or all of the actual processing, and The functions in the above-described embodiments may be realized.

When the present invention is realized by the storage medium described above, a program code corresponding to each process included in the above-described flowchart (see FIGS. 4 and 7) is stored in the storage medium. I'm sorry.

As described above, according to the above-described embodiment, the communication band already assigned to a certain transmission line is still assigned a communication band, and is used as the communication band of another transmission line. can do. Also, since the communication band already assigned to a certain transmission line is only used as a communication band for another transmission line that is still assigned a communication band, if its use is stopped It can be used immediately as the communication band of the original transmission line. Also, by using the assigned communication band as another communication band, it is not necessary to have a communication band originally required for another transmission path, so that efficient provision of a communication band as a wireless communication system can be realized. Can.

[0171] Further, the transmission path used to transmit data to another wireless communication apparatus can be switched between the first transmission path and the second transmission path. Furthermore, when switching between the first transmission path and the second transmission path, the wireless communication control unit uses the communication band assigned to the transmission path before switching as the communication band for the transmission path after switching. Data can be transmitted to other wireless communication devices using a later transmission path. Further, since the communication band assigned to the transmission path before switching is maintained, data transmission is continued using the transmission path before switching even during the processing for securing the band on the transmission path after switching. be able to. Therefore, since the interruption time of data transmission does not occur in the switching process of the transmission path, it becomes possible to eliminate the possibility that the delay time is generated due to the interruption of data transmission and the delay bound value allowed for transmission is exceeded. That is, it is possible to prevent the loss of the real time property of data transmission.

Further, since communication bands on the first and third transmission paths are always assigned, if the communication band on the first transmission path is used as it is, the other radio is transmitted using the first transmission path. Data can be transmitted to the communication device. Furthermore, by using the communication band on the first transmission line as the communication band on the fourth transmission line to the relay station in the second transmission line, the second transmission line is combined with the communication band on the third transmission line. To transmit data to other wireless communication devices Can be Therefore, since the interruption time of data transmission does not occur in the switching process of the transmission path, it becomes possible to eliminate the possibility that the delay time is generated due to the interruption of data transmission and the DelayBound value allowed for transmission is exceeded. That is, it is possible to prevent the real time property of data transmission from being impaired.

Further, since the communication band on the fourth transmission path is always assigned, by using this communication band as the communication band on the first transmission path, it is possible to use the first transmission path for the other communication band. Data can be transmitted to the wireless communication device. Therefore, since no interruption time of data transmission occurs in the process of switching the transmission line, a delay time is generated due to interruption of data transmission, and it is possible to eliminate the possibility if it exceeds the DelayBound value permitted for transmission. Become. In other words, it is possible to prevent the real-time nature of data transmission from being impaired.

When switching from the first transmission path to the second transmission path, the communication band assigned to the first transmission path before switching is used as the communication band for the second transmission path after switching, and the second transmission is performed. Data can be transmitted to other wireless communication devices using the path.

When switching from the second transmission path to the first transmission path, the communication band assigned to the second transmission path before switching is used as the communication band for the first transmission path after switching, and the first transmission is performed. Data can be transmitted to other wireless communication devices using the path.

Also, for example, it is possible to notify the user of the wireless communication apparatus of the status of the process of switching the transmission path between the first transmission path and the second transmission path. For example, by notifying that the switching process of the transmission line is completed, the user knows that the switching process of the transmission line has just been completed. Also, for example, the user can know what kind of problem is occurring by performing notification processing that switching processing of the transmission path has been canceled due to lack of communication bandwidth. In addition, for example, the user can obtain information such as what to do by notifying the user to move to a better location in the radio wave condition.

Also, the wireless communication apparatus can request the relay station to request the central control station to assign a communication band for the relay station to communicate, and the wireless communication system as a whole can It is possible to increase the flexibility of securing the communication bandwidth of

Also, the wireless communication apparatus can request the relay station to request the central control station to release the communication band for the relay station to communicate, so that the entire wireless communication system can It is possible to increase the flexibility of opening the communication band as a body. In combination with the above invention, for example, when there is not much margin in the communication band in the wireless communication system, when switching the transmission path, the communication band that becomes unnecessary after switching the transmission path is released first, The amount of free bandwidth increases, and it becomes easy to secure the communication bandwidth required after switching the transmission path.

Also, before switching the first transmission path and the second transmission path, it is possible to switch between the first transmission path and the second transmission path by confirming whether there is a vacant communication band or not. Negative power can be predicted, and this information can be used to request for new communication bandwidth assignment and release. For example, it is possible to predict the success or failure of switching of the communication band by acquiring the amount of free band in advance before switching the communication band. In addition, it is possible to reduce the possibility that the communication band can not be secured because the communication band is short.

[0180] In addition, due to the shortage of the free band, it is possible to prevent itself from failing in the process of switching the transmission path between the first transmission path and the second transmission path. In addition, it is possible to avoid a loss of time until the switching of the communication band fails and returns to the state before the switching of the power source.

In addition, it is possible to prevent the communication band assigned to the transmission path before switching from being opened by the central control station.

In addition, other wireless communication devices can be instructed to request the central control station to assign a communication band to the transmission path for the relay station to transmit data, and communication with the central control station can be performed. Flexibility of bandwidth allocation requirements can be enhanced.

In addition, another wireless communication apparatus can be instructed to request the central control station to release the communication band of the transmission line for transmitting data, and communication with the central control station can be performed. Flexibility of bandwidth release requirements can be enhanced.

Further, according to the wireless communication system according to the present embodiment, it is possible to switch the transmission path without impairing the real time property of data transmission.

According to the program product of the present embodiment, the computer executing the program product can switch the transmission path without impairing the real-time property of data transmission. According to the storage medium of the present embodiment, by loading the storage medium into a computer and executing the stored program product, the computer can transmit without impairing the real-time property of data transmission. You can switch the path.

[0187] It should be understood that the embodiment disclosed this time is an example in all points, and it is not restrictive that it can be implemented only in IEEE 802. 1 ie. The scope of the present invention is shown not by the above description but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

Industrial applicability

The present invention relates to a portable telephone, a notebook type personal computer (Personal Computer), and other information processing apparatuses having a communication function, for example, a VTR (Video Tape Recorder), a DVD player and other video recording and reproducing apparatuses, or a television. The present invention is applicable to a receiver and other video display devices.

Claims

The scope of the claims

[1] a wireless communication device,

A transmission / reception unit (206) that transmits / receives data to / from another wireless communication apparatus via a plurality of transmission paths, and a central control station that assigns and opens communication bands And a communication band control unit (208) for controlling the communication band to be used as a communication band of another transmission path not assigned.

[2] The transmission path includes a first transmission path directly transmitting data to the other wireless communication device, and a second transmission path transmitting data to the other wireless communication device via the relay station. The communication band control unit requests the central control station to assign a communication band to a third transmission path from the relay station to the other wireless communication apparatus in the second transmission path. The wireless communication apparatus according to claim 1, further comprising: an other band assignment request instruction unit (211) instructing the relay station to do so.

[3] The communication band control unit further includes an other band release request instructing unit (211) instructing the relay station to request the central control station to release the communication band of the third transmission path. The wireless communication device according to claim 2, comprising.

[4] The transmission path includes a first transmission path directly transmitting data to the other wireless communication device, and a second transmission path transmitting data to the other wireless communication device via the relay station. A wireless communication control unit (205) for switching a transmission channel used to transmit data to the other wireless communication device between the first transmission channel and the second transmission channel. The wireless communication device according to claim 1.

[5] When the wireless communication control unit switches the transmission path from the first transmission path to the second transmission path, the communication band on the first transmission path, and the second transmission in the process of switching After passing through a state in which a communication band on the third transmission path from the relay station to the other wireless communication device in the path is assigned, all communication bands of the first transmission path and the second transmission path are assigned The wireless communication device according to claim 4, wherein the wireless communication device

[6] The wireless communication control unit disconnects the transmission path from the second transmission path to the first transmission path In the case of changing, after passing through a state in which only the communication band on the fourth transmission line from the own apparatus of the second transmission line to the relay station is given in the process of switching, the first transmission line and The wireless communication device according to claim 4, wherein a state in which a communication band of the fourth transmission path is assigned is passed.

[7] When the communication band control unit switches the transmission path used to transmit data to the other wireless communication device between the first transmission path and the second transmission path, 5. The wireless communication apparatus according to claim 4, wherein control is performed to transmit data to the other wireless communication apparatus using a transmission path, and to transmit data indicating the data to the central control station.

[8] A notification unit (214) for notifying of the status of processing of switching a transmission channel used to transmit data to the other wireless communication apparatus between the first transmission channel and the second transmission channel. The wireless communication device according to claim 4, comprising.

[9] A relay destination address setting unit for setting a relay destination address for specifying a relay station for relaying data;

And a receiver address setting unit configured to set a receiver address for specifying a wireless communication apparatus that receives the data.

When the wireless communication control unit switches from the first transmission path to the second transmission path, the relay destination is used to transmit data to the relay station in the communication band to which the central control station power is already assigned. The address setting unit sets the relay destination address to the address of the relay station, and the reception destination address setting unit sets the reception destination address to the address of the other wireless communication apparatus. Wireless communication device.

[10] When the wireless communication control unit switches from the second transmission line to the first transmission line, data is directly transmitted to the other wireless communication apparatus in the communication band already assigned from the central control station. 10. The relay destination address setting unit does not set the relay destination address, and the reception destination address setting unit sets the reception destination address to the address of the other wireless communication apparatus. The wireless communication device according to.

[11] The communication band control unit requests the central control station to assign a communication band for transmitting data to the other wireless communication apparatus, and the central control station assigns a communication band. The wireless communication apparatus according to claim 1, further comprising a vacant band check unit (210) for checking whether or not there is a vacant communication band in the wireless communication system to which the own apparatus currently belongs, depending on whether or not there is no communication.

[12] The wireless communication control unit may stop switching between the first transmission path and the second transmission path when the free band confirmation unit confirms the shortage of the free band. Second

11. The wireless communication device according to item 11.

[13] A wireless communication apparatus as a relay station that receives data of the wireless communication apparatus on the transmitting side via the transmission line and transmits the received data to the wireless communication apparatus on the receiving side via the transmission line,

The transmission path includes a first transmission path directly transmitting data to the other wireless communication device, and a second transmission path transmitting data to the other wireless communication device via the relay station, and a communication band To request that the central control station which assigns and releases the communication band to the third transmission line from the relay station to the other wireless communication apparatus among the second transmission lines. Other band assignment request control unit (310) for requesting the central control station to assign the communication band of the third transmission path when instructed by the wireless communication device of the second aspect; and a communication band is assigned to the third transmission path A wireless communication apparatus, comprising: an attached data transmission control unit (305) that controls transmission of data indicating that the communication has been performed.

[14] When another wireless communication apparatus is instructed to request the central control station to release the communication band of the third transmission line, the central control station transmits the third transmission line Other band release request control unit (310) requesting release of communication band;

The wireless communication apparatus according to claim 13, further comprising: an open data transmission control unit (305) configured to control transmission of data indicating that the communication band of the third transmission path is open.

[15] A wireless communication method for transmitting and receiving data between a first wireless communication device and a second wireless communication device via a plurality of transmission paths,

Detecting a communication band assigned to a certain transmission line among the plurality of transmission lines;

Detected to be used as the communication band of another transmission line to which no communication band has been assigned. And a communication band control step of controlling the communication band.

[16] The plurality of transmission paths may be a first transmission path for directly transmitting data from the first wireless communication device to the second wireless communication device, and the second wireless communication from the first wireless communication device. And a second transmission path for transmitting data to the communication device via the relay station,

The relay station is instructed to request the central control station to assign a communication band to the third transmission path from the relay station to the second wireless communication device among the second transmission paths. The wireless communication method according to claim 15, further comprising another band assignment request instruction step.

[17] The method according to claim 16, further comprising: an other band release request instructing step of instructing the relay station to request the central control station to release the communication band of the third transmission path. The wireless communication method described in.

[18] The plurality of transmission paths are a first transmission path for directly transmitting data from the first wireless communication device to the second wireless communication device, and the second wireless communication from the first wireless communication device. And a second transmission path for transmitting data to the communication device via the relay station,

The wireless communication control step according to claim 15, further comprising: a wireless communication control step of switching a transmission channel used to transmit data to the second wireless communication device between the first transmission channel and the second transmission channel. Wireless communication method.

[19] When the wireless communication control step switches from the first transmission path to the second transmission path, a communication band on the first transmission path in the process of switching, and the relay of the second transmission path A state in which a communication band on the third transmission line from the station to the second wireless communication apparatus is given, and then a state in which all the communication bands on the first transmission line and the second transmission line are given The wireless communication method according to claim 18, wherein e.

[20] When the wireless communication control step switches from the second transmission line to the first transmission line, in the process of switching, the first wireless communication device of the second transmission line to the relay station The method according to claim 18, wherein after passing through the state in which only the communication band on the fourth transmission path is assigned, the state in which the communication bands on the first transmission path and the fourth transmission path are assigned is passed. Wireless communication method.

[21] When the wireless communication control step switches from the first transmission path to the second transmission path, at least a communication band on the first transmission path in the process of switching, and the second transmission path to the central control station The wireless communication method according to claim 18, wherein a state in which a communication band on the third transmission path from the relay station to the second wireless communication device is assigned is passed.

[22] When the wireless communication control step is to switch from the second transmission path to the first transmission path, a process from the first wireless communication device to the relay station in the second transmission path may be performed in the switching process. The wireless communication method according to claim 18, wherein a state in which only the communication band on the four transmission paths is provided is passed.

[23] When the transmission path used to transmit data from the first wireless communication device to the second wireless communication device is switched between the first transmission path and the second transmission path, Further comprising transmitting data indicating that data is being transmitted from the first wireless communication device to the second wireless communication device using the transmission path of A wireless communication method according to claim 18.

[24] Notification of status of processing for switching a transmission path used to transmit data from the first wireless communication device to the second wireless communication device between the first transmission path and the second transmission path The wireless communication method according to claim 18, further comprising the step of:

[25] A relay destination address setting step of setting a relay destination address for specifying a relay destination for relaying data;

And a receiver address setting step of setting a receiver address for specifying a wireless communication apparatus that receives the data.

When the wireless communication control step switches the transmission path from the first transmission path to the second transmission path, in order to transmit data to the relay station in the communication band to which the central control station is assigned. The relay destination address setting step sets the relay destination address to the address of the relay station, and the reception destination address setting step sets the reception destination address to the address of the second wireless communication apparatus. The wireless communication method according to paragraph 18.

[26] When the wireless communication control step switches from the second transmission line to the first transmission line In order to directly transmit data to the second wireless communication device in the communication band already assigned from the central control station, the relay destination address setting step does not set the relay destination address, and the reception is performed. The wireless communication method according to claim 25, wherein the destination address setting step sets the destination address to the address of the second wireless communication device.

[27] Requests the central control station to assign a communication band for transmitting data to the second wireless communication apparatus, and the current status of the second control is determined depending on whether or not the central control station communication band is assigned. The wireless communication method according to claim 15, further comprising an empty band confirmation step of confirming whether or not there is a vacant communication band in the wireless communication system to which the wireless communication device belongs.

[28] The free band confirmation step requests the central control station to provide a communication band obtained by adding a communication band desired to be newly added to the communication band to which the central control station power is already added, and the central control The wireless communication according to claim 27, wherein it is checked whether there is a vacant communication band in the wireless communication system to which the first wireless communication apparatus currently belongs, depending on whether the communication band is given or not. Method.

[29] The free band confirmation step assumes transmission of data for a communication band desired to be newly assigned, requests the central control station to assign the communication band, and the communication band is requested from the central control station. The wireless communication method according to claim 27, wherein whether or not there is a vacant communication band in the wireless communication system to which the first wireless communication apparatus currently belongs is checked depending on whether or not it is given.

[30] The method according to claim 1, further comprising the step of: stopping switching of the transmission path between the first transmission path and the second transmission path when the free band confirmation step confirms the shortage of the free band. Range A wireless communication method according to paragraph 27.

[31] A first wireless communication apparatus, and a second wireless communication apparatus connected to the first wireless communication apparatus via a network, the first wireless communication apparatus comprising:

A transmitting / receiving unit that transmits / receives data to / from the second wireless communication device via a plurality of transmission paths

206) and

Central control station that assigns and opens communication bands is assigned to a certain transmission line A wireless communication system, comprising: a communication band control unit (208) for controlling the communication band to use the communication band as a communication band of another transmission path to which the communication band is not assigned.

[32] A first wireless communication device, and a second wireless communication device connected to the first wireless communication device via a network, the first wireless communication device comprising:

A wireless communication apparatus as a relay station that receives power data of a transmitting wireless communication apparatus via a transmission line and transmits the received data to a receiving wireless communication apparatus via the transmission line,

Instructed by the wireless communication device of the transmitting side to request the central control station which assigns and releases the communication band to assign the communication band to the first transmission path to the wireless communication device of the receiving side. And another band assignment request control unit (310), which requests the central control station to assign the communication band of the first transmission path.

A wireless communication system, comprising: an attached data transmission control unit (305) for controlling transmission of data indicating that a communication band is assigned to the first transmission path.

[33] A program product for causing a computer to function as a wireless communication device, the program product comprising:

A step of transmitting / receiving data to / from another wireless communication device via a plurality of transmission paths, and a central control station that assigns and opens a communication band A communication band is assigned to a communication band assigned to a certain transmission path. And controlling the communication band to be used as a communication band for the other transmission path.

[34] A program product for causing a computer to function as a wireless communication device, wherein the wireless communication device receives data from a wireless communication device on the transmission side via a transmission path, and transmits the received data to the transmission path. A wireless communication apparatus as a relay station for transmitting data to a wireless communication apparatus on the receiving side via the network;

Instructed by the wireless communication device of the transmitting side to request the central control station which assigns and releases the communication band to assign the communication band to the first transmission path to the wireless communication device of the receiving side. Requesting the central control station to provide a communication band for the first transmission path,

Controlling transmission of data indicating that a communication band is assigned to the first transmission path Program products that run

[35] A storage medium storing the program product according to claim 33 or claim 34.