JP2003060564A - Radio communication system in radio network, radio communication method, radio communication equipment, band allocation method and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable continuous band reservation over a plurality of frames, in the case that band reserving transmission is performed by using a part of the frame. SOLUTION: In a radio communication system having a periodical frame structure, as a method for performing band reserving transmission of the plurality of frames by one time reservation request, reservation is released when transmission is finished or cut off from a network is performed, and band reservation is performed over the continuous plural frames.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a wireless communication system in a wireless network, a wireless communication method, a wireless communication device, a band allocation method, and a computer program.

[0002]

2. Description of the Related Art As a circuit-switching type wireless communication method for a mobile phone or the like, a transmission frame period is set, a partial area within the frame period is defined as a slot, and the slot is transmitted from a communication device. The method of exclusive use was used for the information transmission.

In such a conventional wireless communication system,
For the slot that is allowed to be used exclusively, a method of continuously using the slot has been used unless the user disconnects the line. That is, the protocol has been designed so that once the slot is assigned so that it can be exclusively used, the use of the transmission line is not interrupted against the user's intention.

As a communication method of the wireless LAN, for example, the standard IEEE (Institute of Electrical and Ele
ctronics Engineers) The 802.11 system defines the optimum protocol for asynchronous wireless transmission.

On the other hand, various proposals have been made for a wireless communication system having a periodic frame structure, for example, HiperLAN2 and Wireless1394 are being studied. In a wireless communication system having these frame structures, a band reservation communication method is used in which a band used for transmission is reserved in advance prior to information transmission. As these band reservation communication methods, a method of making a band reservation for each frame cycle that is periodically defined is generally used.

As an example of a method for reserving a band for each frame synchronization, FIG. 19 shows a conventional case where a band is reserved for only one frame. 19 (A) to 19 (D)
Corresponds to the first to fourth frames, which are a series of frames.

In the figure, a predetermined transmission frame period is determined by network broadcast transmissions B31 and B32.

First, the communication device having the reservation request performs the transmission Q31 of the reservation request in the reserved area of the second frame (FIG. 19 (B)).

If the reservation request Q31 is received by the control station of the network and the reservation is possible, the subsequent third frame
In the network broadcast transmission B33 of FIG. 19C, the reserved transmission area is designated.

Next, the information transmission source device, which is the communication device having the reservation request, receives the network broadcast information B33, and based on the parameter (transmission start / end timing), the third frame (Fig. 19 (C)), transmission S31 of reserved transmission is performed.

Then, in the next fourth frame (FIG. 19 (D)), the network broadcast information B34 in which the reserved transmission area is not designated is transmitted from the control station, and the band reserved transmission is completed.

Further, in the conventional radio communication system,
Generally, the information to be transmitted is discontinuous information, and all the processing is completed by one bandwidth request.

FIG. 18 is a diagram showing an example of a frame when a continuous band reservation is made by the conventional method. FIG.
(A) to (G) correspond to a first frame to a seventh frame which are a series of frames.

In the figure, a predetermined transmission frame cycle is determined by network broadcast transmissions B41 and B42.

Next, the communication device having the reservation request performs transmission Q41 of the reservation request in the reservation area of the second frame. (FIG. 18 (B)). If the reservation request Q41 is received by the network control station and the reservation is possible, the reservation transmission area is designated by the network broadcast transmission B43 in the next third frame (FIG. 18C). The information transmission source device (terminal station) receives this network broadcast information B43, and its parameters (transmission start / end timing)
Based on the above, transmission S41 of reserved transmission is performed.

On the other hand, the information transmission source device transmits a reservation request Q42 in the reserved area of the third frame (FIG. 18C) in order to continuously transmit information.

When the reservation request Q42 is received by the network control station and the reservation is possible, the next fourth frame
In the network broadcast transmission B44 of FIG. 18D, the reserved transmission area is designated.

The information transmission source device receives the network broadcast information B44, and performs the transmission S42 of the reservation transmission based on the parameter (transmission start / end timing). Here, the information transmission source device transmits the reservation request in the reservation area of the fourth frame (FIG. 18D) prior to this in order to continuously perform the information transmission in the next fifth frame. Perform Q43.

When the reservation request Q43 is received by the network control station and the reservation is possible, the reservation transmission area is designated by the network broadcast transmission B45 of the next fifth frame (FIG. 18E). . The information transmission source device receives the network broadcast information B45, and performs reservation transmission transmission S43 based on the parameter (transmission start / end timing). On the other hand, the information transmission source device transmits a reservation request Q44 in the reserved area of the frame in order to continuously transmit information in the next frame.

When the reservation request Q44 is received by the control station of the network and the reservation is possible, the next sixth frame
In the network broadcast transmission B46 of FIG. 18 (F), the reserved transmission area is designated. The information transmission source device receives this network broadcast information B46 and, based on the parameter (transmission start / end timing), transmits the reserved transmission S4.
Do 4 Here, since the information transmission source device does not continuously transmit information in the next frame, it does not transmit in the reserved area.

After that, the following seventh frame (FIG. 18 (G))
At, the network broadcast information B47 in which the reserved transmission area is not designated is transmitted from the control station, and the band reserved transmission is completed.

[0022]

The above-mentioned conventional techniques have the following problems.

In a circuit-switching type wireless communication system such as a mobile phone, the slot is not released unless the user makes a circuit disconnection request because the disconnection in the wireless transmission path is not likely to occur. Therefore, wireless
When the conventional circuit switching type communication protocol is applied to the LAN system, if the link between the control station and the terminal station cannot be secured, for example, the control station can communicate by moving the terminal station. If it goes out of range, the slot assigned to the terminal station cannot be released.

By the way, when a plurality of wireless communication devices are combined to construct a wireless network and a large amount of information such as video information is stream-transmitted from one communication device to another communication device for a long time, There was a problem of occupying one medium. As a solution to this, a method has been devised in which a transmission frame period is set and a part of the frame period is exclusively used for stream transmission.

However, in the conventional method as shown in FIG. 18 described above, as long as the stream transmission is continued, the processing concerning the transmission band reservation must be continuously performed, and the same reservation request is issued. There was a problem that it had to be repeated. In this conventional method, there is a problem that the stream transmission is interrupted if the processing of the transmission band reservation cannot be performed. Therefore, in a general wireless LAN system having a frame structure, such a method is used. If adopted, bandwidth reservation must be continued for each frame.

However, in a system such as a wireless LAN, the connection between both the information transmission source device and the information reception destination device may become unstable due to the positional relationship between these devices, the distance, and the occurrence of obstacles. There may occur a case where the bandwidth cannot be reserved temporarily. In such a case, there are many cases where stream transmission cannot be performed, or there is a possibility that stream transmission that has started once is frequently interrupted. In addition, in FIG. 18 and FIG.
The example in which the frame period determined by the beacon is constant is shown, but as disclosed in Japanese Patent Laid-Open No. 2000-517132, the beacon transmission interval (frame period) in order to avoid collision of wireless beacons transmitted from the base station. When is variable, the following problems occur. That is, since the frame length changes every time, for example, in the case of stream transmission, it is desired to guarantee a bandwidth of 20 Mbps, but since the frame period is short, 20 Mbps within one frame.
The situation occurs in which the time slot for s cannot be assigned. In such a case, it will be transmitted over multiple frames, but if the transmitting terminal and receiving terminal do not know such information in advance, the transmission / reception timing of data cannot be determined until the beacon is heard each time. It will be. Further, when the data is transmitted over a plurality of frames, the receiving terminal needs to perform processing such as once accumulating in the buffer.

The present invention has been made in view of the above problems, and a first object of the present invention is to provide a radio communication system using a synchronous frame defined by network broadcast information. The purpose of the present invention is to provide a method for continuously performing bandwidth reservation over a plurality of frames when performing bandwidth reservation transmission using a part of this frame.

A second object of the present invention is to switch between a one-time bandwidth reservation and a continuous bandwidth reservation depending on the application to be transmitted.

As a first method for achieving the above object, when performing stream transmission for a long time,
A method of making a transmission band reservation without setting an end time and releasing the transmission band reservation at the end of transmission is devised.

Further, a method is devised by which the control station releases the transmission band when the communication device that was performing the stream transmission is no longer present in the wireless network.

As a second method for achieving the above object, a method is devised in which, when stream transmission is performed for a long time, an end time (number of frames) is set in advance to reserve a transmission band.

If the stream transmission is continued even when the end time comes, the end time is again set.
We will devise a method to set the (number of frames) and reserve the transmission band.

[0033]

The present invention has the following features as means for solving the above problems.

A first aspect of the present invention is a wireless communication system in which wireless communication is performed between a plurality of wireless communication devices using a frame having a cycle determined by network broadcast information, wherein the wireless communication device has the frame cycle. A band reservation request is transmitted to the control station using a part of the, the control station transmits band allocation information in response to the band reservation request from the wireless communication device, and the wireless communication device allocates from the control station. A wireless communication system is characterized in that wireless communication is performed using the allocated band, and the band reservation request is such that a band reservation request is made once to make a band reservation over a plurality of frames.

In the wireless communication system, a part of the band of a frame is reserved at the start of transmission, and then a part of the frame is exclusively used, and the band is released at the end of the transmission. Further, when the wireless communication device that has reserved the band no longer exists in the network, the control station of the network may determine that the transmission is completed and release the band.

Alternatively, the band reservation request information for band reservation may include information on the number of frames to be continuously reserved.

In a second aspect of the present invention, in a wireless communication method using a frame having a cycle determined by network broadcast information, a wireless communication device belonging to a wireless network formed by a control station requests a bandwidth reservation request to the control station. And a step of receiving band allocation information from the control station by the wireless communication device, and a step of performing wireless communication using the band allocated from the control station, the band reservation request, A wireless communication method is characterized in that a bandwidth reservation is made over a plurality of frames by a single bandwidth reservation request.

According to this method, a band reservation is performed by determining an end time limit at the start of transmission, and when the band reservation transmission is continued, the band reservation is performed again before the end time limit is reached.

Alternatively, the band reservation request information for band reservation may include information on the number of frames to be continuously reserved.

A third aspect of the present invention is to transmit a band reservation request for band reservation transmission in a wireless communication device that performs wireless communication using a frame having a cycle determined by network broadcast information, A wireless communication unit for receiving the band allocation information; and a control unit characterized by controlling the wireless communication unit to perform information transmission in a part of the frame period based on the band allocation information. Then
The bandwidth reservation request is in the wireless communication device, wherein the bandwidth reservation is made over a plurality of frames by one bandwidth reservation request.

Further, a fourth aspect of the present invention is to control a wireless network formed by a plurality of wireless communication devices in a wireless communication device for performing wireless communication using a frame having a cycle determined by network broadcast information. Means for managing as a station, means for receiving a band reservation request from a wireless communication device belonging to the network, and means for allocating a part of the frame period to the wireless communication terminal that has transmitted the band reservation request, Reservation request is 1
A wireless communication device is characterized in that a bandwidth reservation is made over a plurality of frames by a single bandwidth reservation request.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Configuration Example of Wireless Network] First, a configuration example of the wireless network system according to the present embodiment will be described. FIG. 1 is a diagram showing a configuration example of a wireless network system. The wireless network system shown in the figure
The wireless communication device includes a plurality of wireless communication devices T1 to T8, and each communication device is a wireless communication device capable of transmitting and receiving a signal according to a predetermined transmission method.

In the example shown in the figure, the communication device T8 is
It is assumed to function as a control station of the illustrated wireless network. The other wireless communication devices T1 to T7 mutually transmit and receive wireless signals as terminal stations belonging to the wireless network. The communication device T8 is in a state in which it can easily communicate with all of the other communication devices T1 to T7, and therefore, it is at an appropriate position where the control information from the control station can be sent to the communication devices T1 to T7 as the terminal stations. is there.

Further, in the wireless network in the illustrated example, the communication device cannot necessarily directly perform wireless communication with all other communication devices. In the example shown,
For example, since the communication device T1 is located relatively close to the communication devices T2, T7, and T8, information can be easily transmitted without losing information due to attenuation of radio signals. On the other hand, the communication device T1 has communication devices T3 and T6.
Since it exists at a position relatively distant from, the information transmission may be a little difficult in some cases. Further, the communication device T1 is far from the communication devices T4 and T5 and cannot directly perform wireless communication.

Similarly, from the other communication device T2 to the communication device T
Each of 7 has a communication device that can easily transmit information, a communication device that is difficult to transmit information, and a communication device that cannot transmit information.

[Configuration Example of Wireless Communication Device] Next, a configuration example of a wireless communication device configuring the wireless network will be described. The wireless communication device has a wireless transmission unit for performing a transmission function and a wireless reception unit for performing a reception function.

[Configuration Example of Wireless Transmission Unit] FIG. 2 shows a configuration example of the wireless transmission unit of the wireless communication device.

Here, an interface 71 for connecting to an external device (not shown) is provided, a receiving buffer 72 for storing the wirelessly transmitted media information 701 received from the external device is provided, and information is temporarily stored. It is composed.

This communication device (hereinafter, “communication device” refers to a wireless communication device unless otherwise specified) is provided with a control unit 76 for performing a series of transmission processing, and a wireless transmission notification 702 indicates a band. If reservation transmission is necessary, a reservation request 703 is stored in the transmission buffer 73 for wireless transmission,
Reservation request 70 to the control station using a predetermined request area
4 is wirelessly transmitted from the antenna 75 via the wireless communication unit 74.

In the network broadcast information periodically sent from the control station, a signal 705 decoded by the wireless communication section 74 via the antenna 75 is sent to the control section 76.
The control unit 76 supplies the corresponding reserved band allocation information 706 to the reserved transmission processing unit 77.

Further, the information stored in the reception buffer 72 is supplied to the transmission buffer 73 as predetermined transmission information, and the reserved transmission processing unit 77 performs control 708 of wireless transmission at a predetermined time of the frame period, At that timing, the transmission information 709 is wirelessly transmitted at a predetermined time.

These series of controls are performed by the instruction of the control unit 76, and the control unit 76 is configured to include an information storage unit 78 in which various transmission control programs and control information are stored.

FIG. 3 is a block diagram showing an example of the configuration of the wireless reception unit of the wireless communication device.

Here, an antenna 81 for receiving a radio signal and a radio communication unit 82 for decoding a signal 801 received by the antenna are provided, and a network broadcast signal periodically sent from the control station. 802 is output from the wireless communication unit 82 and notified to the control unit 86.

Here, the control unit 86 supplies the reserved bandwidth allocation information 803 included in the network broadcast information to the reserved transmission processing unit 87.

Further, the reserved transmission processing section 87 is configured to perform reception processing at the timing 804 designated by the reserved band allocation information and store the received information 805 in the reception buffer 83.

Further, the control unit 86 reconstructs the reception information 807 and transfers it to the transmission buffer 84 according to the instruction 806 in frame cycle units.

Then, a predetermined interface format 808 is transferred to an external device (not shown) via the interface 85. A series of these controls is performed according to an instruction from the control unit 86, and the control unit 86 includes an information storage unit 88 that stores various transmission control programs and control information.

The radio transmitter and the radio receiver need not be independent of each other, but the corresponding components, such as the controllers 76 and 86, the information storage 78, and the like.
88, reception buffers 72, 83, transmission buffers 73, 8
4, interfaces 71 and 85, antennas 75 and 81
One may be configured to be commonly used by the wireless transmission unit and the wireless reception unit.

The communication device serving as the control station (communication device T8 in the example shown in FIG. 1) also has the same wireless communication section and wireless reception section as described above. However, the control units 76 and 86
Then, the function as a control station (for example, execution of network broadcast transmission, bandwidth reservation management, allocation, etc.) is executed.

FIG. 4 shows an example of a frame structure set by the control station (communication device T8).

In the figure, the transmission frame cycle 20 is a network broadcast information area (B: Beacon) 21 that is broadcast on the network from the control station at the beginning of the frame, and, for example, processing when entering the network. Contention Access Period (CAP) 22 for performing communication and non-contention transmission area (CFP: Contention Free Period) 23 for each communication device to perform bandwidth reservation and information transmission.
And have. Network Broadcast Information Area (B: Beac
The transmission frame period 20 is from the start of (on) 21 to the start of the next network broadcast information area.

Further, the non-contention transmission area 23 is a request area (REQ) 24 for transmitting a reservation transmission request, a reservation transmission area (RSV) 25 where band reservation transmission is performed, and an unused area 26 which is not used for transmission. May be included.

It should be noted that the frame configuration described above is merely an example, and the frame configuration used by the wireless network system according to the present invention is not limited to this example.

[First Band-Reserved Transmission Method] Next, when performing band-reserved transmission using a part of this frame in a wireless communication system having a periodic frame structure, it is continued over a plurality of frames. As one method of bandwidth reservation, we explain a method of reserving a part of the frame at the start of transmission, then exclusively using a part of the frame and releasing the band at the end of transmission. To do.

FIG. 5 is a diagram showing transitions of reservation requests and reservation transmissions of consecutive frames in the bandwidth reservation transmission method according to the embodiment of the present invention. Note that FIG. 5A to FIG.
(G) corresponds to a first frame to a seventh frame, which are a series of frames in which the band reservation transmission method is executed. Further, in this band reservation transmission method, the information transmission source device notifies the control station of the band reservation at the start of the transmission and notifies the control station of the band release at the end of the transmission.

The band reservation transmission method will be described below with reference to FIGS. 5 and 6.

First, a predetermined transmission frame cycle is determined by the network broadcast transmissions B51 and B52. here,
5 and 6 show the case where the frame period is fixed, the frame period may be variable. One frame is a cycle from the network broadcast information (beacon) to the next network broadcast information.

Next, the wireless communication device having a reservation request (referred to as an information transmission source device) makes continuous transmission Q5 of the reservation request in the reservation area of the second frame (FIG. 5 (B)). If the network control station receives the continuous reservation request Q5 and the continuous reservation is possible, in the network broadcast transmission B53 in the subsequent third frame (FIG. 5C),
Specify the reserved transmission area. The information transmission source device receives this network broadcast information B53, and performs reserved transmission S51 in this third frame based on the parameter (transmission start / end timing).

From the fourth frame (FIG. 5 (D)), as long as the communication device exists in the network, the designated reserved transmission area is exclusively assigned as the transmission band for the reservation of the information transmission source device. To be Therefore, the information transmission source device does not need to transmit the reservation request in the reserved area after the next frame. That is, the control station is the fourth
In the network broadcast information B54 of the frame (FIG. 5D), continuous reservation transmission is designated so that the designated reservation transmission area is exclusively given to the information transmission source device. The information transmission source device uses this network broadcast information B5.
4 receives and sends a reserved transmission based on its parameters S
Do 52. Similarly, the control station may move to the next fifth frame (see FIG.
(E)) The continuous broadcast transmission is also designated in the network broadcast information B55. The information transmission source device receives this network broadcast information B55, and performs reservation transmission transmission S53 based on the parameter thereof. In this transmission S53, it is assumed that the information transmission to be transmitted is completed. In addition,
In FIG. 5, the information transmission slots (S51 to S53) assigned by the control station are described at the same position in the frame, but the information transmission slot may change for each frame.

In the following sixth frame (FIG. 5 (F)),
The control station also designates continuous reservation transmission in the network broadcast information B56. On the other hand, since the information transmission is completed, the information transmission source device determines that the sixth frame (see FIG.
Band release request R5 is transmitted in the reserved area of (F). When the network control station receives the band release request R5, in the subsequent seventh frame (FIG. 5 (G)), the control station transmits network broadcast information B57 with no designation of the reserved transmission area. This completes the band reservation transmission. The released band can be used for other communication. In FIG. 5, after the control station receives the continuous reservation request Q5, the network broadcast information B53,
The case where the transmission terminal specifies the reserved transmission area to be transmitted in each frame of B54 and B55 has been described, but in the network broadcast information B53 after receiving the reservation request Q5, for example, channels up to three frames ahead Assignment information may be sent. In that case, the network broadcast information B
54 and B55, the same information as the network broadcast information B53 is transmitted. By doing so, even if any of the network broadcast information B53, B54, and B55 cannot be received, the normal decoding can be performed. Further, in FIG. 5, the reservation request Q5 continued by the control station is a band reservation request for the frame immediately after,
As shown in FIG. 6, a continuous reservation request may be made for frames several frames after the reservation request is transmitted. Figure 6
FIG. 6 is a diagram showing a transition of reservation requests and reservation transmission of continuous frames in the bandwidth reservation transmission method when a reservation request is continuously made for a frame several frames after the reservation request is transmitted according to the embodiment of the present invention. Here, as an example, it is assumed that the bandwidth reservation for the frames from the 10th frame to the 20th frame is made by the continuous reservation request Q5. FIG. 6 shows continuous frames from the first (F1) to the twentieth (F20), and in the figure, the area B5
2 to B71 are network broadcast information transmitted in each frame, and in the figure, S61 to S70 are
It is an information transmission slot allocated in the 10th (F10) to 20th (F20) frames. In the case of this example, from the frame (F2) immediately after receiving the reservation request Q5 to the frame (F11) in which data is actually transmitted, 10
Although the network broadcast information (B53 to B62) of the times is transmitted, it is also possible to divide the continuous band allocation information and transmit it through the network broadcast information of the ten times. By receiving the network broadcast information (B53 to B62) 10 times, the terminal (wireless communication device) B62 to B7 at which the data is actually transmitted.
The transmission band in one frame (F11 to F20) will be recognized. Also, if the band allocation information is repeatedly transmitted without being divided and the network synchronization information of any one of the network synchronization information B53 to B62 can be received as in the above-described embodiment, the terminal (wireless communication device) determines the transmission band. You may make it recognizable.

[Transmission Reservation Operation Sequence of Information Transmission Source Device] Next, the operation of the information transmission source device in this bandwidth reservation transmission method will be described. FIG. 7 is a diagram showing a transmission reservation operation sequence by the information transmission source device.

First, in the interface section of the communication device,
Determine whether a request to send information to be transmitted wirelessly has arrived
(Step 141).

If there is an information transmission request, the type of information to be transmitted is confirmed (step 142).

Then, it is judged whether band reserved transmission is necessary (step 143), and if necessary, it is further judged whether continuous transmission is required as stream transmission (step 144). For example, if the application to be transmitted is image information or music data, it is determined that continuous transmission is necessary.

If it is continuous transmission, continuous band reservation is set (step 145). If it is transient transmission, band reservation is set only once, and the band cycle request information indicates the frame cycle. Using the designated reserved area, the data is transmitted to the wireless communication device serving as the control station (step 147).

If it is determined in step 143 that bandwidth reserved transmission is not necessary, it is appropriately transmitted in a non-reserved competitive transmission area based on a predetermined access control method (CSMA / CA) (step 140). ).

If there is no information to be transmitted by radio in the judgment of step 141, it is judged whether the band is continuously reserved (step 148). If the band is continuously reserved, Set the release of the bandwidth reservation
(Step 149) Using the reserved area in which the frame cycle is designated as the bandwidth reservation release information, the information is transmitted to the wireless communication device serving as the control station (step 150).

[Operation of Control Station] Next, the operation of the control station in this band reservation transmission method will be described. FIG. 8 is a diagram showing the operation of the control station in this band reservation transmission method.

First, the control station determines whether or not the band reservation request wirelessly transmitted from the communication device in the network has been received (step 161).

If received, it is judged whether the band can be reserved (step 162). If the reservation is possible, the control station designates the transmission start time and the end time within one frame as the designation of the band for the reserved transmission (step 163) and registers it as the network broadcast information, which will be described later. Go to step 165. on the other hand,
If the reservation cannot be made, a reservation transmission impossible notification is set and registered as network broadcast information (step 164). Then, the process proceeds to step 165 described later.

If the bandwidth reservation request has not been received in step 161, the process proceeds to step 165.

The control station detects whether a communication device belonging to the network has disappeared from the network (step 165). When the disappearance is detected, it is judged whether or not the communication device has reserved the band (step 166). If the band has been reserved, the reserved transmission band is set to be released (step 167). on the other hand,
If the communication device has not disappeared or the band has not been reserved, the process proceeds to the next step 168.
The processes from step 165 to step 167 may be configured to be performed for all communication devices belonging to the wireless network.

Then, the control station determines whether or not the network broadcast transmission time has arrived at a predetermined frame period (step 168), and if it has arrived, transmits the network broadcast (step 169). . On the other hand, if it is not the network broadcast transmission time, this processing is exited.

This completes the operation sequence of the control station.

[Operation after Bandwidth Reservation Request of Information Transmission Source Device]
Next, the operation of the information transmission source device after the bandwidth reservation request in the present bandwidth reservation transmission method will be described. FIG. 9 is a flowchart showing the operation of the information transmission source device after the bandwidth reservation request.

First, the information transmission source device determines whether it has received the network broadcast information wirelessly transmitted from the control station device of the network (step 171).

When it is received, the frame period is synchronized (step 172), and it is further determined whether band reservation transmission is designated in the frame broadcast information (step 173). If so, the reserved transmission area is set (step 174). On the other hand, if band reservation transmission is not designated, the process proceeds to step 177.

If the band is continuously reserved, the information transmission source device determines whether or not the transmission timing designated by the control station has arrived even if the network broadcast of the frame cannot be received ( Step 175). When the designated transmission timing arrives, the information transmission source device performs a stream transmission process of a predetermined band reservation transmission.
(Step 176). On the other hand, if the transmission timing has not arrived, the process proceeds to step 177 described later.

Next, whether the information transmission source device needs to disconnect from the network, for example, when communication with the control station is not established over a plurality of frame periods or when power is not supplied to this communication device. Is determined (step 177). If the information transmission source device determines that disconnection from the network is necessary, the information transmission source device releases the reserved transmission band (step 178) and ends the stream transmission.

The information transmission source device operates so as to periodically repeat the above flow.

[Operation of Information Receiving Destination Device] Next, the operation of the information receiving destination device (communication device which is the destination of the information transmitted from the information transmitting source device) in the present bandwidth reserved transmission method will be described. FIG. 10 is a flowchart showing the periodical operation of the information receiving device.

First, the information receiving apparatus determines whether or not the network broadcast information wirelessly transmitted from the network control station apparatus has been received (step 181).

When the information is received, the information receiving apparatus performs the synchronization processing of the frame period (step 18).
2) Further, it is judged from the reservation information or the like included in the network broadcast information whether or not the band reservation transmission to the self is designated (step 183). If done,
The reserved transmission area is set (step 184).
On the other hand, if the band reserved transmission is not designated, the process is terminated.

If the band is continuously reserved after setting the reserved transmission area, the information receiving device is designated to perform reserved transmission even if it cannot receive the network broadcast of the frame. It is determined whether the timing has come (step 185). When it arrives, a stream reception process of a predetermined band reservation transmission is performed (step 186). On the other hand, if the timing has not arrived, the process is exited.

The information receiving device operates so as to periodically repeat the above sequence.

[Advantages of First Band-Reserved Transmission Method] According to the band-reserved transmission method described above, when the band-reserved transmission is performed, the transmission band is continuously reserved over a plurality of frames so that each frame cycle It is possible to omit performing bandwidth reservation processing, and it is possible to simplify the processing sequence. Furthermore, by releasing the reserved bandwidth when the bandwidth reservation transmission is completed, the bandwidth reservation for which the transmission is completed can be released immediately and can be used for wireless transmission of other communication devices. It becomes possible to use resources efficiently.

[Second Band-Reserved Transmission Method] Next, as another method of continuously band-reserving over a plurality of frames, the information transmission source device determines the end deadline at the start of transmission and reserves the band. A description will be given of a band reservation transmission method characterized in that when the band reservation transmission is continued, the band reservation is made again before the end time limit is reached. Hereinafter, a case where the information transmission source device determines how many frames are continuously reserved for bandwidth will be described.
The information may be determined by the control station in consideration of the amount of information (for example, the number of bytes) that the information transmission source device requested to transmit.

FIG. 11 is a diagram showing transitions of reservation requests and reservation transmissions of consecutive frames in this band reservation transmission method. 11A to 11O correspond to the first to fifteenth frames, which are a series of frames in which the present band reservation transmission method is executed. The band reservation transmission method will be described below with reference to FIG.

First, network broadcast transmissions B601 and B602
The predetermined transmission frame period is determined by.

A wireless communication device (information transmission source device), which belongs to the wireless network and has a reservation request, receives the second frame.
In the reserved area of FIG. 11 (B), a reservation request Q61 for reservation of a frame continued for a predetermined time (or a predetermined number of frames) is transmitted. here,
For convenience, an example is shown in which a continuous reservation request is made up to four frames ahead, but the implementation of the method is not limited to four frames, and reservations can be made for any number of frames.

Now, the reservation request Q61 is received by the control station of the wireless network. The control station checks the usage status of the wireless network resource and the like, and if it can respond to the continued reservation, the next third frame
In the network broadcast transmission B603 (FIG. 11C),
Specify the reserved transmission area. In this description, it is assumed that reservation is possible. The information transmission source device receives the network broadcast information B603 and transmits the reservation transmission S601 based on the parameter (transmission start / end timing).

From the fourth frame (FIG. 11 (D)) through the sixth
In each frame up to the frame (FIG. 11 (F)), the area corresponding to the reserved transmission S601 is exclusively assigned to the reserved transmission of the information transmission source device. Therefore, the information transmission source device does not transmit the reservation request in the reserved area of the third frame (FIG. 11 (C)) to the fifth frame (FIG. 11 (E)). That is, the control station specifies the continuous reserved transmission for exclusive allocation to the reserved transmission of the information transmission source device in the network broadcast information B604 of the next fourth frame (FIG. 11 (D)). Do. The information transmission source device receives the network broadcast information B604 and transmits the reservation transmission S602 based on the parameter.

Similarly, the control station also designates continuous reservation transmission in the network broadcast information B605 in the next fifth frame (FIG. 11 (E)). The information transmission source device receives the network broadcast information B605 and transmits the reservation transmission S603 based on the parameter.

Similarly, the control station also designates continuous reserved transmission in the network broadcast information B606 in the next sixth frame (FIG. 11 (F)). The information transmission source device receives the network broadcast information B606 and transmits the reservation transmission S604 based on the parameter. here,
Since the continuous reservation of four frames is completed, the information transmission source apparatus reserves the reserved area in the sixth frame (FIG. 11 (F)) if it is necessary to continuously transmit information after the next frame. In, it is necessary to continuously transmit the reservation request. In this example, the information transmission source device needs to continuously transmit information even after the next frame, and the reservation request Q62 is continuously transmitted.

The control station checks the usage status of the wireless network resource and if it is possible to comply with the continued reservation, the network broadcast in the next seventh frame (FIG. 11 (G)). The reserved transmission area is designated by transmission B607. In this description, it is assumed that reservation is possible. Now, the information transmission source device receives this network broadcast information B607 and transmits the reservation transmission S605 based on the parameter (transmission start / end timing).

From the eighth frame (FIG. 11 (H)) onwards, the first
In each frame up to 0 frame (Fig. 11 (J)),
The area corresponding to the reserved transmission S605 is exclusively allocated to the reserved transmission of the information transmission source device. Therefore, the information transmission source device operates from the seventh frame (FIG. 11G) to the ninth frame.
The reservation request is not transmitted in the reserved area of the frame (FIG. 11 (I)). That is, the control station specifies the continuous reserved transmission for exclusive allocation to the reserved transmission of the information transmission source device in the network broadcast information B608 of the next eighth frame (FIG. 11 (H)). I do. The information transmission source device receives the network broadcast information B608 and transmits the reservation transmission S606 based on the parameter.

Similarly, the control station also designates continuous reservation transmission in the network broadcast information B609 in the next ninth frame (FIG. 11 (I)). The information transmission source device receives the network broadcast information B609 and transmits the reservation transmission S607 based on the parameter.

Similarly, the control station sends the next tenth frame.
Also in the network broadcast information B610 in FIG. 11 (J), continuous reservation transmission is designated. The information transmission source device receives the network broadcast information B610, and transmits the reservation transmission S608 based on the parameter. here,
Since the continuous reservation of four frames starting from the seventh transmission frame ends, if the information transmission source device needs to continuously transmit information even after the next frame, the information transmission source device may not transmit the first transmission frame.
In the reserved area in the 0 frame (FIG. 11 (J)), it is necessary to continuously transmit the reservation request. In this example, the information transmission source device needs to continuously transmit information even after the next frame, and the reservation request Q63 is transmitted continuously.

If the continuous reservation request Q63 is received by the network control station and continuous reservation is possible, the next
In the 11th frame (FIG. 11 (K)), the network broadcast information B611 is transmitted and the reserved transmission area is designated.

The information transmission source device receives this network broadcast information B611, and based on the parameter (transmission start / end timing), transmission S609 of reserved transmission is performed.

The control station receives the next twelfth frame (see FIG. 11).
Also in the network broadcast information B612 of (L), continuous reservation transmission is designated (S610), but when the information transmission ends, the information transmission is not performed. In this example, it is assumed that the information transmission ends at the information transmission source and the reserved transmission is not performed.

Similarly, the thirteenth frame (FIG. 11 (M)), the first
Network broadcast information B613 of 4 frames (Fig. 11 (N)),
Also in B614, the designation of the continuous reserved transmission (S611, S612) is performed, but since the information transmission has been completed, the information transmission source device does not perform the information transmission S611, S612.

In the subsequent fifteenth frame (FIG. 11 (O)), the control station transmits the network broadcast information B615 which does not specify the reserved transmission area. This completes the band reservation transmission.

[Transmission Reservation Operation Sequence of Information Transmission Source Device] Next, the operation of the information transmission source device in this bandwidth reservation transmission method will be described. FIG. 12 is a diagram showing a transmission reservation operation sequence by the information transmission source device.

First, it is determined whether or not a request for transmission of information to be wirelessly transmitted has arrived at the interface section of the information transmission source device (step 151).

Here, if there is an information transmission request, the parameter is set so that the bandwidth is reserved for a certain period (step 152). Next, it is judged whether or not the band is being reserved (step 153). If the band is not reserved, the process moves to step 155 which will be described later from the branch of "NO".

On the other hand, when the reservation is made, it is judged whether or not the reservation is just before the end, that is, the last frame of the plurality of reserved frames (step 154).
Immediately before the end, the reserved area in which the frame cycle is designated is used as the bandwidth reservation request information and transmitted to the communication device serving as the control station (step 155).

On the other hand, if it is determined in step 154 that the band reservation is not completed immediately before, there is no need to transmit an unnecessary request signal, and the process is terminated.

If it is determined in step 151 that there is no information to be wirelessly transmitted, the process ends.

At this time, the release sequence of the first invention may be implemented as necessary.

[Advantages of Second Band-Reserved Transmission Method] According to the band-reserved transmission method described above, when band-reserved transmission is performed, by setting a predetermined end time, it is possible to continue over a plurality of frames. The transmission band can be reserved by using the transmission band, and it becomes unnecessary to perform the band reservation process for each frame period. Furthermore, when the transmitting communication device is no longer in the network, it can be released naturally without performing release processing, and that area can be used for wireless transmission of other communication devices. It becomes possible to efficiently utilize network resources.

Further, when the stream transmission is continued, the bandwidth reservation is set again with a predetermined end time, so that the bandwidth can be repeatedly reserved until the end of the stream transmission, and the stream transmission can be performed efficiently. It becomes possible to do it.

[Operation of Control Station, Operation of Information Transmission Source Device After Request for Bandwidth Reservation, Operation of Information Receiving Device] Operation of Control Station and Operation of Information Transmission Source Device after Request for Bandwidth Reservation The operation of the information receiving device is the first
This is basically the same as the case of the band reservation transmission method of.

[Configuration Example of Bandwidth Reservation Request Information, Network Broadcast Information, Bandwidth Reservation Release Information] Next, the band reservation request information used in the first band reservation transmission method or the second band reservation transmission method, Network broadcast information,
A configuration example of the bandwidth reservation release information will be described.

FIG. 13 shows an example of a band reservation sequence corresponding to a part of the above-mentioned first and second band reservation transmission methods.

First, the information transmission source device 91 to the control station 92
The bandwidth reservation request information 94 is transmitted to. Based on the request 94, the control station 92 broadcasts the reserved band information as a network broadcast signal 95 on the network, and the network broadcast information 94 including the reserved band information is transmitted to the information transmission source device 91 and the information transmission source device 91. It reaches the information receiving device 93 which is the destination of the information.

Then, the information transmission source device 91 and the information reception destination device 93, which are notified that the band reservation has been made,
When the reserved transmission band designated by the network broadcast signal 95 arrives, band reserved transmission 96 is performed.

When the band reservation transmission 96 is completed,
The information transmission source device 91 transmits the band release request information 97 to the control station 92.

The control station 9 which has received the band release request information 97
Based on this, 2 notifies the communication device (including the information transmission source device 91 and the information reception destination device 93) included in the network of the band release notification as the network broadcast signal 98.

In the second bandwidth reservation transmission method, the network broadcast signal 98 including the bandwidth release request information 97 and the bandwidth release notification is not used.

Next, a configuration example of the bandwidth reservation request information 94 will be described. FIG. 14 is a diagram showing a configuration example of the bandwidth reservation request information 94 shown in FIG.

This information 94 indicates information used when a device that makes a band reservation makes a band reservation request to a device that serves as a control station of the network. In the configuration example, the bandwidth reservation request information 94 includes an identifier 101 indicating a bandwidth reservation request, an information length 102 in which the length of this information is described, and an address 103 of the transmission source communication device of this information. , The address 104 of the communication device that receives this information
And a reservation number for uniquely identifying a certain bandwidth reservation request
105, required bandwidth information 106 indicating the bandwidth of the bandwidth corresponding to the amount of information to be transmitted, and continuous frame number information 107 indicating the number of continuous frames when a continuous reservation is made.
And a delay time 108 allowed for band reserved transmission and a code 109 for error detection.

It should be noted that the continuation frame number information 107 is not provided, the amount of information to be transmitted instead is notified, the number of continuation frames is calculated based on the amount of information to be transmitted received by the control station, and this is transmitted to the network broadcast signal. It may be notified as the number of continuous reservation frames 136 of 95.

Next, a configuration example of the band reservation release information 97 will be described. FIG. 15 is a diagram showing a configuration example of the bandwidth reservation release information 97. This information 97 indicates information used when a reserved device releases a reserved band and requests a band reservation from a device that has made a reservation to a device that will be a control station of the network.

In this configuration example, bandwidth reservation release information 97
Is an identifier 111 indicating that the bandwidth reservation is released, an information length 112 in which the length of this information is described, an address 113 of the transmission source communication device of this information, and an address 114 of the reception destination communication device of this information. A reservation number 115 for individually identifying the bandwidth reservation request to be released, release bandwidth information 116 indicating the bandwidth of the bandwidth to be released, and a reserved area (Reserved) 117 which is prepared as necessary, And 118 for error detection.

Next, a configuration example of the network broadcast signal 95 including the reservation notice will be described. FIG. 16 is a diagram showing a configuration example of the network broadcast signal 95. The information of this network broadcast signal 95 is periodically broadcast from the control station and is used for identifying the frame period. This information 96 describes a parameter for bandwidth reservation within the frame period, and the communication device existing in the network controls the information transmission according to this parameter.

In this configuration example, the information of the network broadcast signal 95 includes an identifier 121 indicating network broadcast and an information length 122 describing the length of this information.
, Information 123 for identifying this network, information 124 for devices connected to this network, and information 125 for notifying the position of the competitive transmission area within the frame period.
An information notification 126 indicating the position and allocation of the requested area within the frame period, the first reservation notification information 127 and the second reservation notification information 128 prepared as necessary, and this frame was transmitted. It has time information (time stamp) 129 and code 130 for error detection. In this example, two reservation notification information items are included, but the number of reservation notification information items is not limited to this, and may be any number.

Next, a configuration example of the reservation notification information will be described. FIG. 17 shows a configuration example of the reservation notification information 127 in the information of the network broadcast signal 95. The other reservation notification information 128 has the same configuration.

The reservation notification information is the reservation number 13 for notification.
1 and the address 132 of the information source device that is the source of the information
And the address 133 of the information receiving device that is the destination of the information.
And a time 134 at which reserved transmission can start and a time 135 at which it must end. Further, the number of continuous reservation frames 136 is set as the number of frames reserved after the current frame.

[Advantages of Bandwidth Reservation Request Information, Network Broadcast Information, and Bandwidth Reservation Release Information] By providing an information bit indicating that continuous reservation is to be made in the band reservation information, one-time band reservation and continuous It is possible to identify both the bandwidth reservation method and the optimum bandwidth reservation method according to the information to be transmitted.

By preparing the information about the number of frames to be reserved in the bandwidth reservation information, a method for performing bandwidth reservation transmission for an arbitrary time can be obtained, and there is a method in which the band reservation processing need not be performed for the arbitrary time. Thus, there is an effect that a method for simplifying unnecessary reservation processing can be obtained.

[0144]

According to the present invention, in a wireless communication system using a frame having a period determined by network broadcast information, when band reservation transmission is performed by using a part of this frame, a plurality of frames are spread. Bandwidth can be reserved continuously.

Further, by continuously making a band reservation over a plurality of frames, even if the signal indicating the band reservation from the control station cannot be received due to a change in the radio propagation environment, information can be continuously transmitted and received.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration example of a wireless network system.

FIG. 2 is a block diagram illustrating a configuration example of a wireless transmission unit of a wireless communication device.

FIG. 3 is a block diagram showing a configuration example of a wireless reception unit of the wireless communication device.

FIG. 4 is a diagram showing an example of a frame configuration set by a control station (radio communication device T8).

FIG. 5 is a diagram showing transitions of reservation requests and reservation transmissions of consecutive frames in the bandwidth reservation transmission method according to the embodiment.

FIG. 6 is a diagram showing transitions of reservation requests and reservation transmissions of continuous frames in the bandwidth reservation transmission method when a continuous reservation request is made for a frame several frames after the reservation request is transmitted.

FIG. 7 is a diagram showing a transmission reservation operation sequence performed by the information transmission source device.

FIG. 8 is a diagram showing an operation of a control station in the band reservation transmission method.

FIG. 9 is a flowchart showing an operation of the information transmission source device after requesting a bandwidth reservation.

FIG. 10 is a flowchart showing a periodic operation of the information receiving device.

FIG. 11 is a diagram showing transitions of reservation requests and reservation transmissions of consecutive frames in the bandwidth reservation transmission method.

FIG. 12 is a diagram showing a transmission reservation operation sequence by the information transmission source device.

FIG. 13 is a diagram showing an example of a band reservation sequence corresponding to a part of the band reservation transmission method.

FIG. 14 is a diagram showing a configuration example of bandwidth reservation request information.

FIG. 15 is a diagram showing a configuration example of bandwidth reservation release information.

FIG. 16 is a diagram showing a configuration example of network synchronization information.

FIG. 17 is a diagram showing a configuration example of reservation notification information in the network synchronization information.

[Fig. 18] Fig. 18 is a diagram showing an example of a frame in a case where continuous band reservation is performed by the conventional method.

FIG. 19 is a diagram showing an example of a conventional case where bandwidth reservation is performed for only one frame.

[Explanation of symbols]

T1 to T7 wireless communication devices (terminal stations) T8 wireless communication device (control station) 74, 82 ... Wireless communication unit 77, 87 ... Reservation transmission processing unit 76, 86 ... Control unit 78, 88 ... Information storage unit

Continued front page    F term (reference) 5K033 CA12 DA01 DA17                 5K067 AA13 BB04 BB21 DD04 EE02                       EE10 EE12 JJ11 JJ21

Claims (17)

[Claims] 1. A wireless communication system for performing wireless communication between a plurality of wireless communication devices using a frame having a cycle determined by network broadcast information, wherein the wireless communication device controls using a part of the frame cycle. A band reservation request is transmitted to the station, the control station transmits band allocation information according to the band reservation request from the wireless communication device, and the wireless communication device wirelessly uses the band allocated from the control station. A wireless communication system, wherein communication is performed, and the bandwidth reservation request is such that bandwidth reservation is performed over a plurality of frames by one bandwidth reservation request. 2. A wireless communication method using a frame having a cycle determined by network broadcast information, wherein a wireless communication device belonging to a wireless network formed by a control station transmits a bandwidth reservation request to the control station, The wireless communication device has a step of receiving band allocation information from a control station, and a step of performing wireless communication using the band allocated from the control station, wherein the band reservation request is made by a single band reservation request. A wireless communication method characterized in that bandwidth reservation is performed over a plurality of frames. 3. The wireless communication method according to claim 2, wherein the band allocated by the band reservation request is continuously allocated for transmission of the wireless communication device until a band release request is made. Wireless communication method. 4. The wireless communication method according to claim 2, wherein the band allocated by the band reservation request exists while the wireless communication device that has made the band reservation request exists in a wireless network formed by the control station. A wireless communication method, wherein the wireless communication device is continuously allocated for transmission. 5. The wireless communication method according to claim 2, wherein the bandwidth reservation request includes information regarding a deadline for releasing the allocated bandwidth. 6. The wireless communication method according to claim 2, wherein the band reservation request has information indicating that the band reservation request is a continuous band reservation request over a plurality of frames. 7. The wireless communication method according to claim 2, wherein the bandwidth reservation request includes information about an amount of information to be transmitted, and the information determines the number of continuous frames allocated by the bandwidth reservation request. And a wireless communication method. 8. The wireless communication method according to claim 2, wherein when a continuous band over a plurality of frames is allocated by the control station, the control station does not receive a network broadcast signal transmitted for each frame. A wireless communication method characterized by transmitting and receiving information in the allocated band. 9. A wireless communication device that performs wireless communication using a frame having a cycle determined by network broadcast information, for transmitting a band reservation request for band reservation transmission and receiving band allocation information from a control station. And a control unit characterized by controlling the wireless communication unit to perform information transmission in a part of the frame period based on the band allocation information. A wireless communication device, wherein bandwidth reservation is performed over a plurality of frames by one bandwidth reservation request. 10. The wireless communication device according to claim 9, wherein the control unit controls the wireless transmission unit to transmit a band release request when there is no information to be transmitted. apparatus. 11. The wireless communication device according to claim 9, wherein the band reservation request includes information regarding a deadline for releasing the allocated band. 12. A wireless communication device that performs wireless communication using a frame having a cycle determined by network broadcast information, a means for managing a wireless network formed by a plurality of wireless communication devices as a control station, and the network. And a means for allocating a part of the frame period to the wireless communication terminal that has transmitted the bandwidth reservation request, wherein the bandwidth reservation request is a single bandwidth reservation. A wireless communication device characterized in that a bandwidth is reserved over a plurality of frames according to a request. 13. The wireless communication device according to claim 12, wherein the wireless communication device further receives a band release request from a wireless communication device in the network, and a band allocation within a frame period by the band release request. And a means for transmitting the changed band allocation information to a wireless communication apparatus belonging to the network. 14. The wireless communication device according to claim 12, wherein the band allocated by the band reservation request is present while the wireless communication device making the band reservation request exists in a wireless network managed by the control station. A wireless communication device, wherein the wireless communication device is continuously allocated to the wireless communication device. 15. A band allocating method for allocating a band to a wireless communication device that performs wireless communication using a frame having a cycle determined by network broadcast information, the step of receiving a band reservation request from a wireless communication device belonging to a network. And a step of allocating a part of the frame period to a wireless communication terminal that has transmitted the bandwidth reservation request, wherein the bandwidth reservation request makes a bandwidth reservation over a plurality of frames by one bandwidth reservation request. Band allocation method. 16. A computer program written in a computer-readable format for performing a wireless data transmission / reception operation in a wireless network under the control of a control station, the wireless network being formed by the control station. The wireless communication device to which the wireless communication device belongs transmits a band reservation request to the control station, the wireless communication device receives band allocation information from the control station, and wireless communication is performed using the band allocated from the control station. And a step of performing the bandwidth reservation request, wherein the bandwidth reservation request is such that bandwidth reservation is performed over a plurality of frames by one bandwidth reservation request. 17. A computer program written in a computer-readable format so as to execute a process for operating as a control station for managing a wireless network on a computer system, the bandwidth reservation from a wireless communication device belonging to the network. A step of receiving a request, and a step of allocating a part of the frame period to a wireless communication terminal that has transmitted the bandwidth reservation request, wherein the bandwidth reservation request is to perform bandwidth reservation over a plurality of frames by one bandwidth reservation request. A computer program characterized by the following.