JP2002077984A - Point/multipoint subscriber radio system and transmission band allocating system in point/multipoint radio communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a point/multipoint subscriber radio system where the transmission line of a radio line can be secured and a transmission band can effectively be used in data communication which flows in terms of burst, and to provide a transmission band allocating system in point/multipoint radio communication. SOLUTION: When data to be transmitted is generated, a subscriber station device 20i gives the acquirement request of a preferential reservation slot by a request slot Di (preferential slot request). When data increases in terms of burst and the transmission band lacks only by the preferential reservation slot, the subscriber station device 20i gives the acquirement request of a common reservation slot by the request slot Di (shared slot request). When a base station device 10 receives the request slot Di and the shared reservation slot is idle, it transmits the reservation result of permission to the subscriber station device 20i by using a random access slot R (reservation result notice (permission)).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a point-to-multipoint subscriber radio system comprising a single base station device and a plurality of subscriber station devices.

[0002] The present invention also provides a subscriber station apparatus for accommodating various communication lines from a subscriber apparatus, converting an electric signal from the subscriber apparatus into a radio signal and transmitting the signal, and a plurality of the subscriber station apparatuses. Multipoint subscriber radio system configured to receive a radio signal transmitted from a base station, restore the electric signal to an electric signal, and transmit it to a station equipment in a subscriber network. The present invention relates to a transmission band allocation method in point wireless communication.

[0003]

2. Description of the Related Art A conventional configuration and operation of a point-to-multipoint subscriber radio system will be described with reference to FIGS.

FIG. 6 is a block diagram showing the configuration of a point / multipoint subscriber radio system. In FIG.
Is a base station device, 42a to 42n are subscriber station devices, 44 is station equipment in a subscriber network, and 45a to 45n are subscriber devices.

[0005] The subscriber station devices 42a to 42n are connected to various communication lines (IEEE80) from the subscriber devices 45a to 45n.
2.3, I.P. 431a), and the subscriber device 4
The electric signals from 5a to 45n are converted into radio signals and transmitted to the base station device 41.

[0006] The base station device 41 includes a plurality of subscriber station devices 4.
Radio signals transmitted from 2a to 42n are received, restored to electric signals, and transmitted to the station equipment 44 in the subscriber network.

[0007] Also, the base station device 41 to the subscriber device 45
The flow of signals to a to 45n is such that the same signal flows from the base station device 41 to the plurality of subscriber station devices 42a to 42n by radio signals, and the portion addressed to the own station is transmitted to each of the subscriber station devices 42a to 42n. Extracted and accommodated subscriber units 45a-45n
The signal is sent to the communication line.

In such a point / multipoint subscriber radio system, the signal flows from the base station apparatus 41 to the subscriber station apparatuses 42a to 42n without competing with each other. Regarding the signal flow from the devices 42a to 42n to the base station device 41, it is necessary to control the transmission from the plurality of subscriber station devices 42a to 42n so as not to overlap. Usually, the transmission timing is divided into several time segments (hereinafter referred to as time slots),
A method is used in which the time slots are fixedly assigned so that the time slots do not overlap for each of the subscriber station devices 42a to 42n.

A radio time slot, as shown in FIG. 7, forms a frame with a plurality of time slots.
The downward direction from the base station device 41 is u time slot,
The upstream direction from the subscriber station device 1 is 1 in v time slots.
Make up the frame.

The time slots shown here include a frame start slot F (downstream), a response slot P (upstream), a request slot D (upstream), and a reservation slot A.
(Up direction), random access slot R (down direction), guard slot G (up direction), and the like.

The frame start slot F indicates the head position of the downstream frame. The head position of the upstream frame (normally, the response slot P is placed here) is determined based on the frame start slot F.

In the frame start slot F, the base station device 41 collects and controls status information of the subscriber station devices 42a to 42n in pairs with the uplink response slot P, and determines the type of each time slot. Controls are also included.

The request slot D is reserved for each of the subscriber station devices 42a to 42n in order to secure the reserved slot A in the upstream direction.
Is used to send a request signal to the base station apparatus 41.

The reservation slot A is a time slot for each of the subscriber station devices 42a to 42n allocated by the request slot D.

The random access slot R is provided with destination information as needed by the base station apparatus 41, and each subscriber station 42a
Time slot to be sent to ~ 42n. The reservation result of the uplink reservation slot A by the request slot D is:
The notification is made using the random access slot R.

The guard slot G is used as a buffer slot for preventing signal collision between the request slot D and the reservation slot A after the response slot P.

The assignment of time slots is left to the base station apparatus 41, and each of the subscriber station apparatuses 42a to 42n
The sum of the communication speeds is managed so as not to exceed the wireless transmission band.

As described above, by performing the time slot allocation control between the base station apparatus 41 and the subscriber station apparatuses 42a to 42n, one base station apparatus 41 can control a plurality of subscriber station apparatuses 42a. ~ 42n can be accommodated without any problem.

However, data generation is not constant,
In the communication that flows in a burst, as shown in FIG. 7, if the time slots are exclusively assigned to each of the subscriber station devices 42a to 42n, the transmission band of the wireless line is not effectively utilized. When data is generated in a burst, it may not be possible to send the data due to insufficient bandwidth, and when there is no data, the bandwidth is occupied uselessly.

Therefore, in data communication flowing in a burst manner, as shown in FIG. 8, a method in which the uplink reserved slot A is shared by a plurality of subscriber station devices 42a to 42n can be considered. With this method, one subscriber station device 42i
Can use many time slots at one time, so when data is generated in bursts, a wide transmission band can be secured and the band is not short. When no data is generated,
Without securing a time slot, the time slot can be released to the subscriber station 42j in which other data is generated.

However, according to this method, although the transmission band can be dynamically changed to cope with the generation of data in a burst manner, there is a possibility that the transmission path of the wireless line cannot be secured. For example, if one subscriber station device 42i secures a time slot and starts a relatively long burst transmission operation, during this period, the other subscriber station device 42j
Even if there is data to be transmitted, it will be waited. During this time, data to be transmitted is stored in the buffer memory, and is transmitted when a time slot can be secured.

When the number of the subscriber station devices 42a to 42n is small (n is small), even with this method, a transmission path of a wireless line can be secured as long as a certain transmission delay is allowed.

However, the subscriber station devices 42a-42
When the number of n increases (when n increases), contention for transmission requests frequently occurs, the waiting time becomes longer, and the buffer memory may not be able to absorb the data depending on the data length at that time. Can occur.

In this case, data is discarded, which is regarded as a disconnection of the transmission path. In addition, since the data length at that time is relatively long, if the data length is to be covered by retransmission by the higher-level protocol, the transmission efficiency is further reduced.

As described above, each of the subscriber station devices 42a-42
In the method of allocating time slots exclusively to n (bandwidth-guaranteed data transmission method), the bandwidth is occupied unnecessarily even when there is no data, so that the transmission bandwidth (vacant slot) of the wireless line is used effectively. There is a problem that data is not transmitted, and when data is generated in a burst manner, there is a problem that a band shortage occurs.

On the other hand, in a system (band-shared data transmission system) in which the upstream reserved slot A is shared by a plurality of subscriber station devices 42a to 42n, the subscriber station device 42a is used.
When the number of ~ 42n increases (when n increases),
The contention of transmission requests frequently occurs, the waiting time becomes longer, and depending on the data length at that time, there is a possibility that the data cannot be absorbed by the buffer memory. There was a problem that it was regarded as a notice. In addition, since the data length at that time is relatively long, there is a problem that the transmission efficiency is further reduced if the data length is to be covered by retransmission by the upper layer protocol.

[0027]

As described above, conventionally, in a point-to-multipoint subscriber wireless system, when a method of allocating a time slot exclusively to each subscriber station is applied, data generation occurs. Even when there is no bandwidth, there is a problem that the transmission band of the wireless line is not effectively utilized because the band is wastefully occupied, and there is a problem that when data occurs in a burst, the band becomes insufficient.
In addition, when a system in which a plurality of subscriber station devices share an uplink reserved slot is applied, contention for transmission requests frequently occurs with an increase in the number of subscriber station devices, and the waiting time becomes longer. Depending on the data length at that time, there is a possibility that the data cannot be completely absorbed by the buffer memory. In this case, there is a problem that the data is discarded and the transmission path is regarded as disconnected. Further, since the data length at that time is relatively long, there is a problem that if the data length is to be covered by retransmission by a higher-level protocol, the transmission efficiency is further reduced.

The present invention has been made in view of the above circumstances,
A subscriber station device that accommodates various communication lines from the subscriber device, converts an electric signal from the subscriber device into a radio signal and transmits the radio signal, and a radio signal transmitted from the plurality of subscriber station devices. In a point-multipoint subscriber wireless system composed of a base station device for receiving and restoring an electric signal and transmitting it to a station equipment in the subscriber network, even in data communication flowing in a burst, It is an object of the present invention to provide a point-to-multipoint subscriber wireless system in which a transmission line of a line can be secured and a transmission band can be effectively used, and a transmission band allocation method in point-to-multipoint wireless communication.

[0029]

According to the present invention, several time slots are preferentially assigned to each subscriber station device,
A plurality of other time slots including the time slot to be preferentially allocated are shared by a plurality of subscriber station devices, so that a minimum transmission band of a radio line is secured at least for each of the accommodated subscriber station devices. It is characterized by the following.

That is, according to the present invention, in a point-multipoint subscriber radio system for exchanging information between a single base station apparatus and a plurality of subscriber station apparatuses, the transmission band to be used is set to a band guarantee type. Dividing the fixed allocation band for data transmission and the requested allocation band for band-shared data transmission, allocating a dedicated band for each of the subscriber station devices to the fixed allocation band,
Management means for allocating a preferential use band of each of the subscriber station devices to the requested assigned band, and each of the subscriber station devices, in addition to the dedicated band, a preferential use band assigned to the own device, or to the own device. Transmission control means for transmitting information using the assigned preferential use band and the idle preferential use band assigned to another device, wherein at least each of the accommodating subscriber station devices has the requested assignable band. Characterized in that a minimum transmission band of a radio line can be secured and the transmission band can be dynamically varied.

The present invention also relates to a point-multipoint subscriber wireless system for exchanging information between a single base station apparatus and a plurality of subscriber station apparatuses, wherein a transmission band to be used is changed to a band guarantee type data. A fixed allocation band for transmission, and a request allocation band for shared bandwidth data transmission, and a dedicated band for each of the subscriber station devices is allocated to the fixed allocation band;
Management means for allocating a preferential use band and a shared band of each of the subscriber station devices to the requested assigned band, and each of the subscriber station devices, in addition to the dedicated band, a preferential use band assigned to the own device, or The shared area that is in an idle state with the priority band allocated to the own device, or the priority band that is allocated to the own device and the idle band that is allocated to another device, or allocated to the own device. Transmission control means for transmitting information using the preferentially used band, the shared area in the empty state, and the preferentially used band in the empty state allocated to another device, and at least each of the subscriber station devices accommodated therein. Can secure the minimum transmission band of the wireless line in the requested allocation band,
The transmission band can be dynamically varied.

Further, according to the present invention, in a point / multipoint subscriber radio system for exchanging information between a single base station apparatus and a plurality of subscriber station apparatuses, the transmission band to be used is changed to the band guarantee type data. A fixed allocation band for transmission, and a request allocation band for shared bandwidth data transmission, and a dedicated band for each of the subscriber station devices is allocated to the fixed allocation band;
Management means for allocating a dedicated use band and a shared band of each of the subscriber station devices to the requested allocated band, and the request bandwidth in addition to the dedicated band of each of the subscriber station devices allocated to the fixed allocated band, Transmission control means for transmitting information using the dedicated band of the own device allocated to the allocated band, or the dedicated band of the own device and the shared band in an empty state, and at least the subscriber station device accommodating therein Each of them is characterized in that a minimum transmission band of a wireless line can be secured in the requested allocation band, and the transmission band can be dynamically varied.

Also, the present invention provides a subscriber station device for accommodating various communication lines from a subscriber device, converting an electric signal from the subscriber device into a radio signal and transmitting the radio signal, and a plurality of the subscriber station devices. Band allocation applied to a point-to-multipoint subscriber radio system comprising a base station device for receiving a radio signal transmitted from a base station, restoring the radio signal into an electric signal and transmitting the electric signal to a station equipment in a subscriber network In the system, when allocating a transmission band of a radio line to the subscriber station device, a fixed allocation band for band-guaranteed data transmission is preferentially allocated, and the remaining transmission band is allocated for band-shared data transmission. Allocating a request band to the request allocation area, preferentially allocating a certain amount of transmission band to each of the subscriber station apparatuses, and separately including a transmission band to be preferentially allocated to each of the subscriber station apparatuses. A fixed amount of transmission band is used in common by a plurality of the subscriber station devices, and a fixed transmission band is secured for each subscriber station device to be accommodated by band-guaranteed data transmission. Characterized in that at least the minimum transmission band of the radio line is secured for each subscriber station device to be accommodated.

According to the present invention, there is provided a subscriber station device for accommodating various communication lines from a subscriber device, converting an electric signal from the subscriber device into a radio signal and transmitting the radio signal, and a plurality of the subscriber station devices. Band allocation applied to a point-to-multipoint subscriber radio system comprising a base station device for receiving a radio signal transmitted from a base station, restoring the radio signal into an electric signal and transmitting the electric signal to a station equipment in a subscriber network In the method, when allocating a transmission band of a wireless line to the subscriber station device, a fixed allocation band required for band-guaranteed data transmission is preferentially allocated, and the remaining transmission band is used for band-shared data transmission. A fixed amount of transmission band is exclusively assigned to each of the subscriber station devices in the request assignment region, and the remaining fixed amount of transmission band is shared by the plurality of subscriber station devices. I In addition, the band-guaranteed data transmission ensures a fixed transmission band for each subscriber station device to be accommodated, and the minimum transmission band of the radio line for at least each subscriber station device accommodated in the shared band data transmission. The feature is that it is ensured.

The present invention also relates to a transmission band allocating method in the point-to-multipoint wireless communication, wherein a predetermined amount of a transmission band is preferentially allocated to each of the subscriber station devices in a request allocating area. In the allocation of the transmission band in the allocation area, the transmission timing is divided into several time sections, and the lowest band is preferentially allocated so that the time sections do not overlap for each of the subscriber station devices. When the data generation amount in the subscriber station device is insufficient in the minimum bandwidth, the bandwidth used in common by the subscriber station device is temporarily allocated to the transmission band to the subscriber station device,
It is characterized in that the transmission band of the wireless line of each of the subscriber station devices can be dynamically varied according to a change in the data generation amount.

The present invention also relates to the transmission band allocating method in the point-to-multipoint wireless communication, wherein a fixed amount of a transmission band is exclusively allocated to each of the subscriber stations in a request allocating area. In the allocation of the transmission band in the allocation area, the transmission timing is divided into several time divisions, and the lowest band is exclusively allocated to each of the subscriber station devices so that the time divisions do not overlap. When the data generation amount in the subscriber station device is insufficient in the minimum bandwidth, the bandwidth used in common by the subscriber station device is temporarily allocated to the transmission band to the subscriber station device,
It is characterized in that the transmission band of the wireless line of each of the subscriber station devices can be dynamically varied according to a change in the data generation amount.

The present invention also relates to a transmission band allocating method in the point-to-multipoint wireless communication, wherein a predetermined amount of a transmission band is preferentially allocated to each of the subscriber station devices in a request allocating area. The allocation of the time section in the allocation of the transmission band in the allocation area is preferentially performed for each communication line accommodated in the subscriber station apparatus.

The present invention also relates to a transmission band allocating method in the point-to-multipoint wireless communication, wherein a fixed amount of a transmission band is exclusively allocated to each of the subscriber station devices in a request allocating area. The allocation of the time section in the allocation of the transmission band in the allocation area is exclusively performed for each communication line accommodated in the subscriber station apparatus.

By constructing the point-to-multipoint wireless communication system using the above-mentioned transmission band allocation, the transmission band can be dynamically changed according to the amount of data generated in the request allocation area for band-shared data transmission. Can be varied, and the transmission band of the wireless line can be efficiently used between a plurality of subscriber station devices even for data communication flowing in a burst manner. In particular, when a point / multipoint subscriber wireless system is used as a LAN communication line, since the LAN has very high burstiness, a statistical multiplexing effect of data can be expected, and many subscriber station devices are used. Can accommodate. Incidentally, since the transmission path is shared, there is a possibility that data competition may occur between the subscriber station devices. However, this competition is generated in principle in LAN communication, and is not practical. There is no problem in that.

[0040]

Embodiments of the present invention will be described below with reference to the drawings.

First, a first embodiment of the present invention will be described with reference to FIGS.

In the first embodiment, as described above, when the transmission band of the radio line is allocated to the subscriber station apparatus, the fixed allocation band required for band-guaranteed data transmission is preferentially allocated, and the remaining band is allocated. Is allocated to a request allocation area for band-shared data transmission, and further, several time slots are preferentially allocated to the request allocation area for each subscriber station apparatus. Several other time slots including slots are shared by a plurality of subscriber station devices, so that a minimum transmission band of a radio line is secured at least for each subscriber station device to be accommodated.

FIG. 1 is a block diagram showing a configuration of a point-to-multipoint subscriber radio system according to an embodiment of the present invention. In the drawing, reference numeral 10 denotes a base station device, and 20a to 20a.
n is a subscriber station device. 11 to 14 are constituent elements of the base station apparatus 10, and 11 is an antenna,
Reference numeral 12 is a wireless transmission / reception unit, 13 is a wireless transmission control unit, and 14 is a time slot management table. 21 to 24 are constituent elements of the subscriber station devices 20a to 20n, respectively, 21 is an antenna, 22 is a radio transmission / reception unit, 23 is a radio transmission control unit, and 24 is a time slot allocation table.

In this wireless system, various communication lines (IEEE 802.3, IEEE 802.3,
I. 431a) is converted into a radio signal by the radio transmission / reception unit 22 of the subscriber station device 20 and transmitted to the air via the antenna 21. The wireless transmission control unit 23 of each of the subscriber station devices 20a to 20n has a processor function, and controls the allocation of a desired time slot for each communication line to be accommodated from an upstream signal frame. It is reserved slot A that is assigned. This allocation information is stored in the time slot allocation table 24, and the content is appropriately updated by control communication with the base station device 10.

The base station apparatus 10 includes subscriber station apparatuses 20a to 20a
The radio signal transmitted from the antenna 20n is received by the antenna 11 and restored to an electric signal by the radio transmission / reception unit 12, and is returned to the original communication line form, or in a form in which a plurality of communication lines are concentrated, It is transmitted to the station equipment in the network.

The radio transmission controller 12 of the base station device 10
It has a processor function, and performs time slot allocation control for each communication line and time slot allocation instructions for each of the subscriber station devices 20a to 20n from an upstream signal frame.

The base station apparatus 10 manages time slot allocation information of a plurality of subscriber station apparatuses 20a to 20n accommodated therein, and necessary information is stored in a time slot management table 14.

The contents of the time slot management table 14 are composed of fixed information such as an allowable transmission band and a minimum guaranteed band for each communication line, and variable information that is time slot allocation information of a wireless line. The fixed information is input at the initial stage of accommodating the communication line, and is not rewritten unless the type of the communication line is changed. On the other hand, the variable information dynamically exchanges information between the base station apparatus 10 and the subscriber station apparatuses 20a to 20n in accordance with a change in the amount of data flowing on the wireless line, and changes the transmission band of the wireless line. The contents are sequentially rewritten for effective use.

FIG. 2 is a diagram showing a configuration of an uplink radio time slot in the above embodiment. Here, the uplink wireless time slot is composed of a bandwidth guaranteed data transmission (fixed allocation) slot and a bandwidth shared data transmission (request allocation) slot. Further, the bandwidth sharing type data transmission slot (reservation slot A) includes a priority reservation slot used preferentially by each of the subscriber station devices 20a to 20n and a shared reservation shared by a plurality of subscriber station devices 20a to 20n. Divided into slots.

Further, even if the priority reserved slot is used, when one subscriber station device 20i does not use its own priority reserved slot, another subscriber station device 20j can use it as a shared slot.

From time slots 7 to e, each of the subscriber station devices 20a to 20n is used for band-guaranteed data transmission.
Is a dedicated slot that is fixedly assigned to.

Of the slots for bandwidth sharing type data transmission (request allocation), time slots e + 1 to m are used as priority reservation slots by the subscriber station devices 20a to 20n, and m + 1 to v are subscribed. Party station device 20a
Ｎ20n are used as shared reserved slots. The size of the transmission band is, for example, for the subscriber station device 20i,
Usually, priority is given to three slots from k-2 to k,
When data is generated in a burst, the slots from m + 1 to v and the other subscriber station devices 20a to 20
Slots from e + 1 to m, where n is not currently used, are added, and at least a total (shared + priority) of v
The transmission band is extended to the transmission band of −m + 3 slots. The maximum is
The slots from e + 1 to v will be occupied.

The frame start slot F, response slot P, request slot D, reservation slot A, random access slot R, and guard slot G in the figure are the same as those shown in FIG. Each function is omitted.

A plurality of request slots D (three slots in the figure) are prepared because a plurality of subscriber station devices 20a to 20a are provided.
This is to prevent the base station device 10 from missing the request signal coming from 20n. Which request slot D is used to raise the request is controlled by round robin or the like so that fairness can be maintained among the plurality of subscriber station devices 20a to 20n.

FIG. 3 shows a sequence in which the subscriber station devices 20a to 20n acquire a priority reserved slot and a shared reserved slot in a requested allocated band for band-shared data transmission. Here, as an example, it is assumed that three slots from k-2 to k are previously assigned to the subscriber station device 20i as priority reserved slots.

When data to be transmitted is generated, the subscriber station device 20i issues a request for acquiring a priority reservation slot using the request slot Di [priority slot request].

The base station apparatus 10 transmits the request slot Di
Upon receipt of this, the reservation result of the permission is transmitted to the subscriber station device 20i using the random access slot R [reservation result notification (permission)].

Further, when this data increases in a burst manner and the transmission bandwidth is insufficient with only the priority reserved slots, the subscriber station device 20i issues a request for acquiring a shared reserved slot using the request slot Di [shared slot request].

The base station apparatus 10 transmits the request slot Di
In response, if the shared reservation slot is vacant at that time, the reservation result of permission is transmitted to the subscriber station device 20i using the random access slot R [reservation result notification (permission)].

From this point, the transmission band of the subscriber station device 20i is extended. While the data continues, the expansion of the transmission band is maintained, and when the data is interrupted, both the priority reserved slot and the shared reserved slot are discarded by the request slot Di [priority / shared slot discard].

The base station apparatus 10 transmits the request slot Di
In response, the reservation result of the release is transmitted to the subscriber station device 1i using the random access slot R [reservation result notification (release)].

In the above sequence, a band is secured for data generation.

The same control as described above is performed for the subscriber station device 20j, and the occurrence of data can be handled (sequence from [priority slot request] to [reservation result notification (release)] by request slot Dj). .

Even while the subscriber station device 20j is transmitting data and using the shared reserved slot, data transmission of another subscriber station device 20i is possible during this period (second [priority slot request]). To [reservation result notification (permission)]).

The subscriber station device 20i can use the range from the priority reserved slot k-2 to k to which the subscriber station device 20i is assigned in advance. That is, when receiving the priority slot request of the subscriber station device 20i, the subscriber station device 20j needs to abandon the use of the slots k-2 to k addressed to the subscriber station device 20i [reservation result notification (bandwidth Change)].

When burst-like data generations overlap, the subscriber station device which has issued the shared reservation slot request later waits.

The second shared reservation slot request [shared slot request] by the subscriber station device 20i in the figure is rejected by the base station device 10 because the subscriber station device 20j is already using the same slot [ Reservation result notification (not permitted)].

In this case, the subscriber station device 20i waits for a while before embarking on re-acquisition of the shared reservation slot.
The data during this time is temporarily stored in the buffer memory.

The above description has been made on the case where the priority reservation slot is assigned to each of the subscriber station devices 20a to 20n. However, the priority reservation slot is duplicated for each communication line accommodated in the subscriber station device. By allocating so that it does not become impossible, it is also possible to perform burst communication control in finer units.

Also, by replacing “subscriber station device” in FIGS. 2 and 3 with “communication line”, the diagram can be regarded as a function explanation for each communication line. In this case, the former (shown) secures the minimum transmission band of the radio line for each subscriber station, whereas the latter (when the subscriber station device is replaced with a communication line) uses the minimum for each communication line. The transmission band is secured.

The positioning of the time slots is arbitrary, and the arrangement shown in FIG. 2 is only an example. There is no particular limitation on the data format in each time slot. For example, one time slot may have exactly one ATM cell length, or a frame relay packet may be formed by a plurality of time slots or a plurality of frame time slots. May be.

By constructing the point-to-multipoint wireless communication system according to the first embodiment of the present invention as described above, the transmission band can be dynamically varied according to the amount of generated data, and the data communication for burst-like data communication can be performed. On the other hand, the transmission band of the wireless channel can be used efficiently between the plurality of subscriber station devices.

Next, a second embodiment of the present invention will be described with reference to FIGS. 1, 4 and 5.

In the second embodiment, as described above, when the transmission band of the radio line is allocated to the subscriber station device, the fixed allocation band necessary for the band-guaranteed data transmission is preferentially allocated, and the remaining band is allocated. Is allocated to a request allocation area for shared bandwidth data transmission, and further, in the request allocation area, some time slots are exclusively allocated to each subscriber station apparatus, and the remaining time slots are allocated. Is shared by a plurality of subscriber station devices, so that a minimum transmission band of a wireless line is secured at least for each subscriber station device to be accommodated.

FIG. 4 is a diagram showing the configuration of an uplink radio time slot in the above embodiment. Here, the uplink wireless time slot is composed of a bandwidth guaranteed data transmission (fixed allocation) slot and a bandwidth shared data transmission (request allocation) slot. Further, a slot for shared bandwidth type data transmission (reservation slot A) includes a dedicated reservation slot exclusively used by each of the subscriber station devices 20a to 20n and a shared reservation slot commonly used by a plurality of subscriber station devices 20a to 20n. Divided into slots.

From time slots 7 to e, each of the subscriber station devices 20a to 20n is used for band-guaranteed data transmission.
Is a dedicated slot that is fixedly assigned to.

Of the slots for bandwidth sharing type data transmission (request allocation), time slots e + 1 to m are used as dedicated reservation slots by the subscriber station devices 20a to 20n, and m + 1 to v are subscribed. Party station device 20a
Ｎ20n are used as shared reserved slots. The size of the transmission band is, for example, for the subscriber station device 20i,
Usually, three slots from k-2 to k are secured,
When data is generated in a burst, slots from m + 1 to v are further added, and the total (shared + dedicated) slots is extended to a transmission band of v−m + 3 slots.

The frame start slot F, response slot P, request slot D, reservation slot A, random access slot R, and guard slot G in the figure are the same as those shown in FIG. Each function is omitted.

A plurality of request slots D (three slots in the figure) are prepared because a plurality of subscriber station devices 20a to 20a are provided.
This is to prevent the base station device 10 from missing the request signal coming from 20n. Which request slot D is used to raise the request is controlled by round robin or the like so that fairness can be maintained among the plurality of subscriber station devices 20a to 20n.

FIG. 5 shows a sequence in which the subscriber station devices 20a to 20n acquire a shared reservation slot in a requested allocated band for band-shared data transmission. Here, as an example, three slots from k-2 to k are always reserved as dedicated reserved slots in the subscriber station device 20i.

When data is generated in bursts, the subscriber station device 20i starts to acquire a shared reservation slot by the request slot Di [shared slot request].

The base station apparatus 10 transmits the request slot Di
Upon receiving this, if the shared reservation slot is vacant at that time, the reservation result of permission is transmitted to the subscriber station device 20i using the random access slot R [reservation result notification (permission)].

From this point, the transmission band of the subscriber station device 20i is extended.

While the burst-like data continues, this transmission band expansion is maintained, and when the burst is interrupted, the shared slot is abandoned by the request slot Di [shared slot abandonment].

The base station apparatus 10 transmits the request slot Di
In response, the reservation result of the release is transmitted to the subscriber station device 20i using the random access slot R [reservation result notification (release)].

At this point, the transmission band of the subscriber station device 20i is returned to the original three-slot width.

In the above sequence, a band is secured for the generation of burst data.

The same control is performed for the subscriber station device 20j, and it is possible to cope with bursty data generation ([common slot request] by the request slot Dj).
To [reservation result notification (release)]).

When burst-like data generations overlap, the one who issues a shared reservation slot request later waits. The second shared reservation slot request [shared slot request] by the subscriber station device 20i in FIG.
0j is already using the same slot.
[Reservation result notification (non-permission)].

In this case, the subscriber station device 20i starts to reacquire the shared reservation slot after a while.
The data during this time is temporarily stored in the buffer memory.

In the above description, a case is described in which a dedicated reservation slot is assigned to each of the subscriber station devices 20a to 20n.
By exclusively allocating a dedicated reservation slot for each communication line accommodated in n, burst communication control can be performed in smaller units.

Also, by replacing the “subscriber station device” in FIGS. 4 and 5 with a “communication line”, the diagram can be regarded as a functional description for each communication line. In this case, the former is a method of securing the minimum transmission band of the radio line for each subscriber station, while the latter is a method of securing the minimum transmission band for each communication line.

The positioning of the time slots is arbitrary, and the arrangement shown in FIG. 4 is merely an example. There is no particular limitation on the data format in each time slot. For example, one time slot may have exactly one ATM cell length, or a frame relay packet may be formed by a plurality of time slots or a plurality of frame time slots. May be.

By constructing the point-to-multipoint wireless communication system according to the second embodiment of the present invention as described above, the transmission band can be dynamically varied according to the amount of data generated, and the data communication for burst-like data communication can be performed. On the other hand, the transmission band of the wireless channel can be used efficiently between the plurality of subscriber station devices. In particular, when a point / multipoint subscriber wireless system is used as a LAN communication line, since the LAN has very high burstiness, a statistical multiplexing effect of data can be expected, and many subscriber station devices are used. There is an advantage that can be accommodated. Also, in the method of the present invention, data competition may occur between the subscriber station devices because the transmission path is shared,
This competition occurs in principle in LAN communication, and has no problem in practical use.

[0095]

As described in detail above, the points of the present invention are as follows.
According to the transmission band allocation method in the multipoint subscriber radio system and the point / multipoint radio communication, the transmission band can be dynamically varied according to the amount of generated data, and even for data communication flowing in a burst,
The transmission band of the wireless line can be used efficiently between a plurality of subscriber station devices. In particular, when a point / multipoint subscriber wireless system is used as a LAN communication line, since the LAN has very high burstiness, a statistical multiplexing effect of data can be expected, and many subscriber station devices are used. Can accommodate. Also, in the present invention, since the transmission path is shared, there is a possibility that data competition may occur between the subscriber station apparatuses, but this competition occurs in principle in LAN communication. Therefore, there is no problem in actual use.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a point-to-multipoint subscriber wireless system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a frame configuration corresponding to data communication flowing in a burst according to the first embodiment of the present invention.

FIG. 3 is a sequence diagram for explaining the operation of the system according to the first embodiment.

FIG. 4 is a diagram showing an example of a frame configuration corresponding to data communication flowing in a burst according to the second embodiment of the present invention.

FIG. 5 is a sequence diagram for explaining the operation of the system according to the second embodiment.

FIG. 6 is a block diagram showing a configuration of a conventional point-multipoint subscriber wireless system.

FIG. 7 is a diagram showing a frame configuration example of a wireless time slot in a conventional point-multipoint subscriber wireless system.

FIG. 8 is a diagram showing an example of a frame configuration corresponding to data communication flowing in bursts in a conventional point-multipoint subscriber wireless system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Base station apparatus 11 ... Antenna 12 ... Wireless transmission / reception part 13 ... Wireless transmission control part 14 ... Time slot management table 20a-20n ... Subscriber station apparatus 21 ... Antenna 22 ... Wireless transmission / reception part 23 ... Wireless transmission / reception part 24 ... Time slot Assignment table

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Claims (9)

[Claims] In a point-multipoint subscriber wireless system for exchanging information between a single base station apparatus and a plurality of subscriber station apparatuses, a transmission band to be used is changed for a band-guaranteed data transmission. A fixed allocated band and a required allocated band for shared bandwidth data transmission are divided, a dedicated band for each of the subscriber station devices is allocated to the fixed allocated band, and each of the subscriber station devices is preferentially used for the required allocated band. Management means for allocating a band, and in addition to the dedicated band, each of the subscriber station devices has a preferentially used band assigned to its own device, or a preferentially used band assigned to its own device and a free space assigned to another device. Transmission control means for transmitting information by using the priority use band in the state, wherein at least each of the subscriber station devices accommodated in the request allocation band, the minimum transmission band of the radio line Securing can, and point-to-multipoint subscriber radio system, characterized in that to be able to vary the transmission band dynamic. 2. In a point / multipoint subscriber wireless system for exchanging information between a single base station apparatus and a plurality of subscriber station apparatuses, a transmission band to be used is changed for a band-guaranteed data transmission. A fixed allocated band and a required allocated band for shared bandwidth data transmission are divided, a dedicated band for each of the subscriber station devices is allocated to the fixed allocated band, and each of the subscriber station devices is preferentially used for the required allocated band. Management means for allocating a band and a shared band, and each of the subscriber station apparatuses is in an idle state with the preferential use band assigned to the own apparatus or the preferential use band assigned to the own apparatus in addition to the dedicated band. The shared area, or the preferentially used band assigned to the own device and the unused preferentially used band assigned to another device, or the preferentially used band assigned to the own device Transmission control means for transmitting information using the shared area in the empty state and the preferentially used band in the empty state allocated to another apparatus, wherein at least each of the subscriber station apparatuses accommodating the required allocated band 2. A point-to-multipoint subscriber radio system according to claim 1, wherein a minimum transmission band of the radio line can be secured and the transmission band can be dynamically varied. 3. In a point-multipoint subscriber wireless system for exchanging information between a single base station device and a plurality of subscriber station devices, a transmission band to be used is changed for a band-guaranteed data transmission. A fixed allocation band and a required allocation band for shared bandwidth data transmission are divided, a dedicated band of each of the subscriber station devices is allocated to the fixed allocation band, and a dedicated use of each of the subscriber station devices is allocated to the requested allocation band. Management means for allocating a band and a shared band, and each of the subscriber station apparatuses, in addition to its own dedicated band assigned to the fixed assigned band, its own dedicated band assigned to the requested assigned band, or Transmission control means for transmitting information using the dedicated band of the own device and the shared band that is in an empty state, and at least each of the subscriber station devices accommodated therein is required It can be ensured minimum transmission bandwidth of the line, and points, characterized in that to be able to vary the transmission band dynamic
Multipoint subscriber wireless system. 4. A subscriber station device for accommodating various communication lines from a subscriber device, converting an electric signal from the subscriber device into a radio signal, and transmitting the signal, and a plurality of subscriber station devices. And a base station apparatus for receiving an incoming radio signal, restoring it to an electric signal, and transmitting it to a station facility in the subscriber network. When allocating a transmission band of a wireless line, a fixed allocation band for band-guaranteed data transmission is preferentially allocated, and the remaining transmission band is allocated to a request allocation region for band-shared data transmission, Wherein a certain amount of transmission band is preferentially allocated to each of the subscriber station devices, and another fixed amount of transmission band including the transmission band preferentially allocated to each of the subscriber station devices is assigned to the plurality of subscribers. Localization In common use, bandwidth-guaranteed data transmission ensures a fixed transmission band for each subscriber station device accommodated, and at least for each subscriber station device accommodated in band-shared data transmission. A transmission band allocation method in point-to-multipoint wireless communication, wherein a minimum transmission band of a radio line is secured. 5. A subscriber station device for accommodating various communication lines from a subscriber device, converting an electric signal from the subscriber device into a radio signal and transmitting the signal, and a plurality of subscriber station devices. And a base station apparatus for receiving an incoming radio signal, restoring it to an electric signal, and transmitting it to a station facility in the subscriber network. When allocating a transmission band of a wireless line, a fixed allocation band required for band-guaranteed data transmission is preferentially allocated, and the remaining transmission band is allocated to a request allocation region for band-shared data transmission, the request allocation region A fixed amount of transmission band is exclusively assigned to each of the subscriber station devices, and the remaining fixed amount of transmission band is shared by a plurality of the subscriber station devices to be accommodated by a band-guaranteed data transmission. Do A fixed transmission band is secured for each subscriber station device, and a minimum transmission band of a wireless line is secured for at least each subscriber station device to be accommodated in band shared data transmission. A transmission band allocation method in point-to-multipoint wireless communication. 6. The allocation of the transmission bandwidth in the request allocation area divides the transmission timing into several time divisions, and gives priority to the lowest bandwidth so that the time divisions do not overlap for each of the subscriber station devices. When the amount of data generated in the subscriber station device is insufficient for the minimum bandwidth, the bandwidth commonly used by the subscriber station devices is temporarily allocated to the subscriber station device. 5. The transmission in point-to-multipoint wireless communication according to claim 4, wherein a transmission band of a radio line of each of said subscriber station devices can be dynamically varied according to a change in a data generation amount. Bandwidth allocation method. 7. A method of allocating a transmission band in the request allocation area includes dividing a transmission timing into a plurality of time sections, and excluding a minimum band for each of the subscriber station apparatuses so that the time sections do not overlap. When the amount of data generated in the subscriber station device is insufficient for the minimum bandwidth, the bandwidth commonly used by the subscriber station devices is temporarily allocated to the subscriber station device. 6. The transmission in point-to-multipoint wireless communication according to claim 5, wherein the transmission band of the radio line of each of said subscriber stations can be dynamically varied according to a change in the amount of data generated. Bandwidth allocation method. 8. The method according to claim 4, wherein the allocation of the time division in the transmission band allocation of the request allocation area is preferentially performed for each communication line accommodated in the subscriber station apparatus. Transmission band allocation method in point-to-multipoint wireless communication. 9. The method according to claim 5, wherein the allocation of the time section in the transmission band allocation of the request allocation area is exclusively performed for each communication line accommodated in the subscriber station apparatus. Transmission band allocation method in point-to-multipoint wireless communication.