JP2001148716A - Point-multipoint band sharing system and its band requesting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a request for a band which is always below the maximum capacity without breaking down packet data and to shorten a delay time which is necessary for the band request when arrival intervals of packet data are large by assigning the transfer of variable-length packet data which have unpredictable intervals equally among subscriber devices. SOLUTION: A management table and a capacity counter for individually managing the capacity of packet data arriving at a subscriber-side communication device and the cumulative value of 1st to (n+1)th packet data having arrived is compared with maximum capacity which can be requested at a time; when the cumulative value exceeds the maximum capacity, the cumulative capacity of the 1st to (n)th data is determined as band request capacity. After a value holding transfer capacity information is cleared, a band request is made even if the cumulative capacity is less than the maximum capacity to reduce the transfer delay of packet data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a network configuration in which a plurality of subscriber communication apparatuses and a single office communication apparatus are connected in a point / multipoint topology.
By making unused time slots of a transmission frame transmitted from the subscriber side communication device toward the station side communication device a shared band of a plurality of subscriber side communication devices, the unused time slots are effectively used, and A point-to-multipoint bandwidth sharing system that enables high-speed transfer of packet data at a certain moment by temporarily occupying a shared bandwidth by a specific subscriber communication device, and a plurality of subscriber communication devices to communicate at the station side. The present invention relates to a band request method for requesting a device to use a shared band.

[0002]

2. Description of the Related Art A plurality of subscriber communication apparatuses and an office communication apparatus are connected in a point-multipoint topology, and a frame or voice or the like transmitted between the plurality of subscriber communication apparatuses and the office communication apparatus is transmitted. There is known a transmission method having a shared band in which an unused time slot can be shared by a plurality of subscriber communication apparatuses. Figure 2 shows the points
It is a block diagram which shows the example of a multipoint topology structure. The subscriber communication device (1) 101, the subscriber communication device (2) 102 to the subscriber communication device (n) 103 are connected to the station communication device 104 via the optical coupler 105. Conventionally, in a communication system of a point-multipoint topology, a plurality of subscriber communication apparatuses are used to form a single station communication apparatus as disclosed in Japanese Patent Application Laid-Open No. Hei 4-239241. In the upstream data transfer to 104, a bandwidth is fixedly allocated to each subscriber in a TDMA transmission frame using a TDMA (time division multiple access) method. Band allocation can basically be increased or decreased by fixed setting (soft strap).

FIG. 3 shows a TDMA (time division multiple access) in a conventional point-multipoint topology.
It is a figure showing the example of a transmission frame composition. In the TDMA transmission frame 110, the data transmitted by the first subscriber communication device 101 is in the time slot (1) 106, the data transmitted by the second subscriber communication device 102 is in the time slot (2) 107, n-th subscriber communication device (n)
The data transmitted by 103 is a time slot (n) 108
Are always fixedly allocated, and always occupy the band regardless of the presence or absence of transfer data in the time slot.

When the connection to the Internet or the like is considered by using the TDMA transmission frame 110, the time slots 106 to 108 are used for transferring packet data. However, due to the nature of the packet data, it is not necessary to always occupy the bandwidth, and it is sufficient that the packet data can occupy the bandwidth only when the packet data arrives. Therefore, TD
It is not necessary to always allocate a fixed band to the MA transmission frame 110 at all times. That is, when allocating packet data, a method of fixedly allocating such as the method A is wasteful and cannot use frames efficiently.

[0005] In FIGS. 2 and 3, there is a possibility that unused time slots may occur due to the nature of dividing a large band of the TDMA transmission frame 110 by a plurality of subscriber communication devices. For example, when the number of subscriber communication devices 101 to 103 connected to the station communication device 104 is small, when the bandwidth set individually for each of the subscriber communication devices 101 to 103 is small, or when TDMA transmission is performed. All bands of the frame 110 and each of the subscriber communication devices 101 to 103
When the band allocated to is not equal, the unused time slot 109 always occurs. In FIG.
This unused time slot 109 is defined as a shared band 109, and when the packet data arrives, the station side communication device 104
The communication device on the subscriber side, which needs to transfer data to the mobile station, requests the allocation of the shared band 109, and the station side communication device 104 permits the use of the shared band 109, thereby effectively using the unused time slot 109. Becomes possible.

Effective use of the unused time slot 109 makes it possible to provide a new communication service without changing the line equipment between the subscriber unit and the office unit.
In addition, by sharing the unused time slot 109 with a plurality of subscriber units, it is possible to reduce the cost of communication equipment per subscriber unit. Japanese Patent Application Laid-Open No. Hei 9 (1999) discloses a method in which the station communication device 104 temporarily allocates a band to a specific subscriber device in accordance with a connection request (band request) from the subscriber devices 101 to 103, thereby effectively utilizing the band. There is a line setting method (B method) for a multimedia multiplexing device described in Japanese Patent Application Publication No. 27793.

FIG. 4 is a diagram showing an example of the configuration of a subscriber side communication device according to a conventional line setting method (B system) for a multimedia multiplexing device. In the B system, as shown in FIG. 4, in a communication apparatus having two types of transfer data, that is, a terminal channel 201 and a voice channel 203, data transfer of the terminal channel 201 where delay is relatively tolerable is delayed. When data transfer of the audio channel 203 is not allowed, the audio channel 203 is prioritized.
By operating the switch 301 under the control of the control unit 304, the terminal data 312 is temporarily saved in the buffer memory 303, and after the data transfer of the audio channel 203 is completed, the data is read from the buffer memory 303 and time-division multiplexed. Multiplexed by the processing unit 305 and the terminal channel 20
1 is performed. In the B method, the control unit 3 responds to a connection request signal 202 from the terminal channel 201 and a connection request signal 204 from the voice channel 203.
Reference numeral 04 refers to the connection request signal management table 341 to determine whether or not the channel is a channel to which data is to be transferred preferentially. The path of the non-priority channel to be stored in 303 is selected. In the connection request signal management table 341, a connection request channel number, a data type of a voice system or a terminal system, and a connection allowable time (s) are registered correspondingly.

[0008] When the transfer of the data of the channel to which the data is transferred with priority is completed to the transmission line 205, the data of the non-priority channel is read from the buffer memory 303 by referring to the connection information management table 342, and the transmission line 2
05, the band of the transmission path is effectively used. The B method is effective for a network in which priorities exist between the subscriber units and a relatively delay is allowed in data transfer of the subscribers with lower priorities. It is also effective for a system in which a connection time limit can be set for an audio channel. The B method can be applied to the transmission frame shown in FIG. 3. For example, when there is no telephone call, the transmission data (1) 106 to (3)
108 bandwidth is normally allocated for packet data communication,
When a call such as a telephone call is generated, a method of evacuating packet data to a memory, temporarily stopping communication, and preferentially allocating voice to these bands 106 to 108 can be considered.

[0009]

In the above-mentioned A method, when the unused time slot 109 of the TDMA transmission frame 110 shown in FIG.
In the multipoint topology, there is basically no priority among the communication devices 101 to 103 on the subscriber side.
Only the subscriber who requests the most continuously can use a lot of bandwidth, and each of the subscriber communication devices 101 to 103
A special method is required for fair data transfer between them. In addition, a plurality of subscriber communication devices 101 to 1
It is necessary to simplify the configuration of the station-side communication device 104 handling the request No. 03 and to realize fairness in the subscriber-side communication devices 101 to 103. In the case of the B method described above, the band request from the subscriber side is a connection request, and the priority of the line connection is determined by the table 341 for managing the connection request signal 204 of the voice system. Using this method, a fixedly assigned time slot of the TDMA transmission frame 110 is preferentially assigned when a call such as a telephone call is made, and a method of normally performing packet data communication is adopted. Although fairness among 101 to 103 can be maintained, depending on the use situation of the subscriber, for example, when a long-time call is made, there is a time when packet data cannot be transferred at all, and the efficiency of packet data communication is remarkably increased. May worsen. Usually, a telephone or the like cannot be forcibly disconnected due to a time limit on the system side.

Therefore, as a bandwidth sharing system of a new point / multipoint topology, a subscriber side device 101
TDMA transmission frame 1 between to 103 to station side device 104
A method is also conceivable in which the ten unused time slots 109 are used as a shared band 109 dedicated to packet data separately from a band occupation system service such as telephone. Also, as a method of fairly allocating the shared band 109 to each of the subscriber communication devices 101 to 103, a simple configuration such as a round robin method is used for simplification of the station communication device 104.
A method of sequentially allocating a band while observing a band request of each of the subscriber communication apparatuses 101 to 103 is used.

As described above, the subscriber communication apparatuses 101 to 1
The fairness of the bandwidth allocated between the subscriber communication devices 101
It is necessary to realize by controlling at 103. Therefore, a method is conceivable in which the subscriber communication apparatuses 101 to 103 ensure fairness among the subscriber communication apparatuses by limiting the data capacity for performing one connection request. However, this method is effective when data arriving at each of the subscriber communication devices 101 to 103 from each of the subscriber terminals 1 to 3 has a fixed length and arrives without interruption. If the packet is a variable-length packet and the arrival of data cannot be predicted by the subscriber communication devices 101 to 103,
In other words, when the data arrival interval is irregular, a method for limiting the transfer data capacity that does not cause the data capacity to be interrupted by one connection request, and one connection request when the data arrival interval becomes large. The data transfer delay time to the station side communication device 104 due to waiting for the arrival of the packet data until the capacity reaches the judgment criterion for judging the limitation of the data capacity for performing the data transfer becomes a problem.

Therefore, a first object of the present invention is to solve these conventional problems, and to achieve a bandwidth request of a maximum capacity or less in a point-multipoint bandwidth sharing system so that a variable-length packet arrives sequentially. It is an object of the present invention to provide a point-multipoint bandwidth sharing system and a bandwidth requesting method capable of individually managing the capacity of packet data and maintaining fairness of packet data transfer between subscriber communication apparatuses. . Further, a second object of the present invention is to provide a transmission system in which voice communication is preferentially allocated to a frame and transmitted, whereby packet data can be allocated to a shared band and transmitted regardless of the traffic of the voice communication, Even if the packet data intervals are irregular and variable-length packet data can be allocated to the shared bandwidth of the frame according to the bandwidth request from the subscriber terminal, and the packet data transfer delay time is reduced. It is an object of the present invention to provide a point-to-multipoint band sharing system and a method for requesting the band.

[0013]

In order to achieve the above object, according to the bandwidth requesting method for a point / multipoint bandwidth sharing system of the present invention, packet data arriving at a subscriber side communication device is a variable length packet, When the arrival of data cannot be predicted by the subscriber communication device, the subscriber communication device individually monitors the capacity of the arriving packet data and manages the accumulated capacity to obtain n + 1
When the first packet data arrives, the accumulated capacity of the first to (n + 1) th packet data is always compared with the maximum capacity of the bandwidth that can be requested at one time, and when the accumulated capacity of the first to (n + 1) th exceeds the maximum capacity, 1 A bandwidth request is made by determining the accumulated capacity up to the n-th as a bandwidth requesting capacity. As a result, it is possible to easily realize a bandwidth request that is always equal to or less than the maximum capacity without causing packet data division. In addition, the bandwidth allocation status is monitored, and if a bandwidth is allocated to the bandwidth request, the bandwidth request is cleared once at the same time as the transfer of the packet data, and after confirming that the bandwidth request has not been made, buffering is performed. Even when the accumulated capacity of the packet data is less than the maximum capacity, a bandwidth request for the accumulated capacity of the packet data is immediately made. This allows
The waiting time until the accumulated capacity of the packet data reaches the maximum capacity can be reduced, and the transfer time delay to the station side communication device can be suppressed.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 7 is a configuration diagram of a point / multipoint band sharing system showing one embodiment of the present invention.
The station side communication device 104 and the subscriber side communication device (1) 101,
The point-to-point communication between the subscriber communication device (2) 102 and the subscriber communication device (n) 103 via the optical coupler 105
A multipoint topology is formed, and a plurality of subscriber communication devices are connected to one station communication device 104. The subscriber communication devices 101 to 103 are connected to several types of subscriber terminals (an analog telephone 123, an ISDN terminal 124, and a packet data terminal 125). The analog telephone 123 is connected to the analog telephone
The N terminal 124 is connected to the ISDN interface 122, and the packet data terminal 125 is connected to the band sharing control unit 20. Data received from each of the terminals 123 to 125 is transmitted to the TDMA transmission frame 11 by the framer unit 17.
0 is mapped to a predetermined time slot.

When packet data arrives from the packet data terminal 125, the bandwidth sharing control unit 20 sends the shared bandwidth 1 to the station side communication device 104 via the framer unit 17.
The bandwidth request for assigning 09 is notified. The analog telephone interface 121 and the ISDN interface 122 map the signal from the telephone terminal 124 to a unique time slot assigned to the subscriber communication device 101 via the framer 17 and transmit the signal to the office communication device 104. . In analog telephone and ISDN, a fixed path is always provided so that there may be an incoming / outgoing call at any time.

On the other hand, the station side communication device 104 has a plurality of interfaces (subscriber interfaces 126) with the subscriber side communication devices 101 to 103, and the data received from each of the subscriber side communication devices is shared. Sorting unit 1
Hand over to 31. The distribution unit 131 performs distribution according to the type of the subscriber terminal (the analog telephone terminal 123, the ISDN terminal 124, and the packet data terminal 125). The analog telephone and ISDN are distributed to the exchange interface 127, and the packet data is distributed to the packet data interface 129. The subscriber interface 126 is connected to the framer unit 13.
In 3, the TDMA transmission frame 110 is terminated, and the received data is passed to the distribution unit 126. The assignment control unit 132 calculates T
In order to allocate the shared band 109 of the DMA transmission frame 110 in response to a request from the subscriber communication devices 101 to 103, a round robin circuit for confirming the presence or absence of a request from the subscriber is provided. Apparatus 101 to 103
Check the bandwidth requirements of When the allocation is determined in response to the band request, the frame unit 133 is notified and a band allocation notification is issued to the corresponding subscriber communication device. Upon receiving the band allocation notification, the subscriber communication apparatuses 101 to 103 map the packet data to the shared band 109 and transfer the packet data.

FIG. 3 shows the TDM when the present invention is applied.
It is a figure showing the example of composition of A transmission frame. Unused time slot 1 in addition to time slot (1) 106, time slot (2) 107, and time slot (n) 108 fixedly assigned to each subscriber communication device.
09 is present. The unused time slot 109 is shared by all the subscriber communication apparatuses 101 to 103 as a shared band. According to the present invention, packet data is transferred to an analog telephone, I
Since a band different from that of SDN is used, packet data can be transmitted at any time regardless of the usage status of analog telephone or ISDN.

FIG. 5 is a sequence chart of a method for allocating a bandwidth request for a shared bandwidth according to an embodiment of the present invention. Here, each of the subscriber side communication apparatuses 101 to 103 has the shared band 1
09 by requesting the assignment of the station-side communication device 10.
4 performs scheduling using the round robin method, and as a result, the procedure order of the bandwidth request / allocation method of the point / multipoint bandwidth sharing system for allocating the shared bandwidth 109 to the subscriber communication apparatuses 101 to 103 is shown. . Although not described here, the shared band 109
In the case of allocating to a unique time slot other than the above, since a fixed path is always established between the analog telephone and the ISDN, the framer unit 1 of the subscriber communication apparatuses 101 to 103
At 7, the telephone signal and the ISDN signal are multiplexed and assigned to a unique time slot in the assigned frame, and transmitted to the station side communication device 104.

The subscriber communication device (1) 101, the subscriber communication device (2) 102, and the subscriber communication device (n) 10
3 receives the packet data to be transferred to the station side communication device 104 from each of the subscriber terminals 1 to 3, and makes a bandwidth request S1 ((1) to (n)) to the station side communication device 104, respectively. . The station-side communication device 104 performs the scheduling S2 according to the round robin method. In this case, first, the station-side communication device 104 performs the bandwidth allocation (1) S3 for the subscriber-side communication device (1) 101. The subscriber-side communication device (1) 101 performs bandwidth allocation (1).
Upon receiving S3, the packet data is multiplexed on the shared band 109 and the packet data is transferred to the station side communication device 104 (S4). At the same time, the subscriber communication device 102,
When the bandwidth request S5 is made from 103, the station side communication device 104 performs the scheduling S6 according to the round robin method, and performs the bandwidth allocation (2) S7. As a result, the subscriber communication device 102 multiplexes the packet data on the shared band 109 and transfers the packet data to the station communication device 104 (S8). Hereinafter, similarly, the station side communication device 1
In accordance with the scheduling result of step S04, the subscriber communication apparatuses 101 to 103 transfer packet data (S9).
To S12).

FIG. 1 is a block diagram of a subscriber communication device according to an embodiment of the present invention, which has a detailed configuration of only the subscriber communication device (1) 101 in FIG. 2 shows a configuration. The operation of the point-to-multipoint band sharing system in the subscriber communication device will be described with reference to FIG. The packet data received from the subscriber terminal (1) 1 is normally received by the packet data processing unit 11, and the packet data capacity is individually counted by the capacity counter 12. The capacity counter 12 sends a capacity notification 401 to the capacity management table 13 of the bandwidth request unit 15 together with the packet data arrival notification 402. The capacity management table 13 includes a packet data arrival notification 40 so that the sequentially arriving packet data can be individually recognized.
2. Based on the capacity notification 401, the arrival order of packet data and its capacity are managed on a one-to-one basis. The write control unit 14 controls the address of the buffer memory 16 according to the arrival of the packet data and the capacity of the packet data, and stores the packet data in the buffer memory 16.

The bandwidth request unit 15 refers to the capacity management table 13 and receives an allocation status notification 403 from the bandwidth allocation unit 18.
Is monitored to determine the required capacity, and a bandwidth request is made to the optical line terminal 104 via the framer unit 17. Station-side communication device 104
As a result of the scheduling, it is assumed that the bandwidth allocation is determined for the subscriber communication apparatus (1) 101 to which the bandwidth is allocated.
The station side communication device 104 is a subscriber side communication device (1) 101
To notify the band allocation. The band allocating unit 18 receives the band allocation notification from the framer unit 17, reads the transfer data from the buffer memory 16 through the read control unit 19, performs mapping to the shared band 109 of the TDMA transmission frame 110 by the framer unit 17, and Data transfer to the device 104 is performed. Further, the bandwidth allocating unit 18 notifies the bandwidth requesting unit 15 of the allocation status, and urges the clearing of the bandwidth request accompanying the bandwidth allocation. In the subscriber communication device 101 shown in FIG. 1, a new function provided by the present invention is to provide a management table for individually managing the capacity of packet data arriving at the subscriber communication device, Is counted by the capacity counter 12, and the capacity notification 401 and the arrival notification 4 are sent to the bandwidth requesting unit 15 for managing the management table.
02.

FIG. 6 is a flowchart of a band request sequence operation showing one embodiment of the present invention. The operation of the band request unit 15 of FIG. 1 will be described in detail with reference to the band request sequence of FIG. Starting from an initial state (S21), first,
The arrival number of the packet data is reset (S22), and the arrival notification 402 and the capacity notification 40 from the capacity counter 12 are sent.
Wait for 1 (S23). With the arrival of the first (n = 1) packet data (S24), the flow goes to S25 to determine whether the bandwidth request has been cleared (S25). Since the bandwidth request has been cleared due to the transition from the initial state, the bandwidth request is immediately made (S30). Due to this transition, the bandwidth request is made without waiting for the arrival of the second and subsequent packet data, so that the transfer delay time of the first packet data is reduced. The transfer capacity information is stored in a buffer memory, and the band allocation is notified from the station side communication device 104.
The transition state of the transfer capacity holding changes. In this case, the bandwidth request is also cleared. At this time, even if the accumulated capacity is equal to or less than the maximum capacity, the transfer delay is determined by determining the transfer capacity. The packet data that arrives next becomes the first packet data again by resetting the arrival number (S22).
However, if the previous bandwidth request has not been allocated, that is, if the bandwidth request has not been cleared, the process proceeds to S31, and by setting n = n + 1,
The next packet data that arrives is the second packet data.

The packet data that arrives sequentially from the second onward transitions from S23 to S24 to S26 to S28 to S31 to S23. When it is determined that the bandwidth request has been cleared at S26 when the (n + 1) th packet data arrives, the accumulated capacity of the 1st to (n + 1) th packet data is calculated (S27), and a bandwidth request (S30) is performed. Due to this transition, a bandwidth request can be made continuously even when the accumulated capacity of the first to (n + 1) th packet data does not exceed the maximum capacity (S30). If the bandwidth request has not been cleared at the time of arrival of the (n + 1) th packet data, and the accumulated capacity of the 1st to (n + 1) th has exceeded the maximum capacity of the bandwidth that can be requested at one time, (S
28), calculate the accumulated capacity of the first to n-th packet data (S29), immediately request the bandwidth (S30),
The accumulated capacity of the n-th packet data is determined as the capacity for performing the next bandwidth request. By this transition, a bandwidth request of not more than the maximum capacity is always made, thereby restricting a specific subscriber-side communication device from occupying the shared band.

In the flow shown in FIG. 6, the operation newly performed according to the present invention includes the operation of "the bandwidth request is made without waiting for the next arrival in the case of the first packet" of S24 and the operation of S26.
Operation of “perform bandwidth request without waiting for next arrival even in case of first packet after bandwidth request is cleared” and S28 “determine whether maximum capacity has been exceeded upon arrival of (n + 1) th packet Is determined, and if it exceeds, the first to n-th packets are determined as the bandwidth capacity, and a bandwidth request is made. " In the bandwidth request method of the subscriber communication device according to the present invention, in order to maintain fairness among the subscriber communication devices, the maximum capacity of one bandwidth request is defined, and a bandwidth request less than the maximum capacity is always defined. Perform (S28). Also, as a result of the bandwidth allocation from the station side communication device, monitoring the state where no bandwidth request is issued, and performing the bandwidth request before the accumulated capacity reaches the maximum capacity, when the arrival interval of packet data is large, Reduce the delay time required for bandwidth request (S24, S2
6).

[0025]

As described above, according to the present invention,
In point / multipoint bandwidth sharing system,
By defining the maximum capacity of a single bandwidth request and limiting the cumulative value of the variable-length packet data capacity to make a bandwidth request, the fairness of packet data transfer between subscriber communication devices can be maintained. , And if there is a bandwidth allocation,
By performing the bandwidth request before the accumulated capacity reaches the maximum capacity, it becomes possible to reduce the packet data transfer delay time caused by the limitation of the accumulated value.

[Brief description of the drawings]

FIG. 1 is a block diagram of a subscriber-side communication device of a point-multipoint bandwidth sharing system according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a connection example between a plurality of subscriber communication apparatuses and a station apparatus in a conventional point / multipoint band sharing system.

FIG. 3 is a diagram showing a configuration example of an uplink TDMA transmission frame from a plurality of subscriber communication apparatuses to a station apparatus in a conventional point / multipoint band sharing system.

FIG. 4 is a diagram showing a configuration example of a conventional subscriber side communication apparatus, in which a voice system is preferentially multiplexed and transmitted, and a terminal system is temporarily stored in a buffer memory to effectively use a band. is there.

FIG. 5 is an operation sequence chart of a method for allocating an area request according to an embodiment of the present invention, which is a station-side communication apparatus according to band requests from a plurality of subscriber communication apparatuses in a point / multipoint band sharing system; FIG. 8 is a diagram illustrating an operation of performing scheduling within the network and notifying the subscriber side communication device of the bandwidth allocation.

FIG. 6 is a flowchart of a bandwidth request operation of the point-multipoint bandwidth sharing system according to the embodiment of the present invention.

FIG. 7 is a system configuration diagram of a point / multipoint band sharing system according to an embodiment of the present invention.

[Explanation of symbols]

1, 2, 3 ... subscriber terminal, 11 ... packet data processing unit, 12 ... capacity counter, 13 ... capacity management table, 1
4 Write control unit, 15 Band request unit, 16 Buffer memory, 17 Framer unit, 18 Band allocation unit, 19 Read control unit, 20 Band sharing control unit, 101, 102, 1
03: subscriber communication device, 104: office communication device, 10
5: Optical coupler, 109: Unused time slot (shared band), 106, 107, 108: Time slot fixedly allocated to the subscriber side device, 110: TDMA (Time Division Multiple Access) transmission frame, 121: Analog (Telephone) interface, 122 ... ISDN interface, 12
3 analog telephone, 124 ISDN terminal, 125 packet data terminal, 126 subscriber interface, 1
27: exchange interface, 128: exchange, 129
... Packet data interface, 130 ... Network equipment, 131 ... Distribution unit, 132 ... Allocation control unit, 1
33: Framer unit, 201: Terminal channel, 202:
Terminal channel connection request signal, 203: voice channel, 204: voice channel connection request signal, 205: transmission line, 301: switch, 303: buffer memory, 3
04: control unit, 305: time division multiplex processing unit, 341: connection request signal management table, 342: connection information management table, 401: packet data capacity notification, 402: packet data arrival notification, 403: allocation status notification.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Atsushi Otani 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Communication Systems Division of Hitachi, Ltd. (72) Inventor Koichi Honda 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Address Co., Ltd., Hitachi, Ltd. Communication Systems Division (72) Inventor Hisayuki Kato 216, Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term (Reference) 5K030 HA08 HC14 KA03 5K032 DA03 DA18 DB07 9A001 BB03 BB04 DD10

Claims (5)

[Claims] 1. A plurality of subscriber-side communication devices and an office-side communication device are connected in a point-multipoint topology.
Since packet data is transferred between a plurality of subscriber communication devices and a central communication device using a shared band, which is an unused time slot of a transmission frame, the packet data sent from the subscriber terminal is temporarily transmitted to the subscriber terminal. When it is stored in the buffer memory of the communication device on the side and makes a bandwidth request to the communication device on the station side,
The station-side communication device selects a subscriber-side communication device to which a band is to be allocated, and notifies the selected subscriber-side communication device of a bandwidth allocation. A bandwidth requesting method for a point-multipoint bandwidth sharing system for transferring packet data stored in a communication device to a station-side communication device, wherein the subscriber-side communication device has various arriving capacities sequentially and the capacity cannot be predicted. The packet data capacity is individually counted and managed for each packet data, and the maximum capacity of the bandwidth that can be requested at one time is defined, and the accumulated capacity and the maximum capacity of the first to (n + 1) th packet data are repeatedly compared.
Point multi-function wherein, when the cumulative capacity of the 1st to n + 1th packet data exceeds the maximum capacity, the bandwidth requesting capacity is determined as the cumulative capacity of the 1st to nth packet data and a bandwidth request is made. Point bandwidth request method for bandwidth sharing system. 2. The bandwidth requesting method for a point-to-multipoint bandwidth sharing system according to claim 1, wherein the subscriber-side communication device determines a cumulative capacity of the first to n-th packet data as a bandwidth requesting capacity. After the bandwidth request is made, the cumulative capacity of the (n + 1) to (n + m + 1) th packet data is repeatedly compared with the maximum capacity of the bandwidth that can be requested at one time, and the cumulative capacity of the (n + 1) to (n + m + 1) th packet data exceeds the maximum capacity. A bandwidth requesting method for a point-multipoint bandwidth sharing system, wherein a bandwidth to be requested next is determined at a point in time as a cumulative capacity of packet data of the (n + 1) to (n + m) th packet data. 3. The bandwidth requesting method for a point-to-multipoint bandwidth sharing system according to claim 1, wherein said subscriber-side communication device requests the first to n-th packets previously requested by a bandwidth allocation from a station-side communication device. At the same time as the data is transferred, it is monitored that the bandwidth requests of the first to nth packet data have been cleared, and the capacity of the first packet data arriving for the first time thereafter is immediately changed to the capacity required for the next bandwidth request. And a bandwidth request is made to the point-multipoint bandwidth sharing system. 4. The bandwidth requesting method for a point-to-multipoint bandwidth sharing system according to claim 1, wherein said subscriber-side communication device requests a bandwidth for the accumulated capacity of the first to n-th packet data, and said station-side communication device. In the state of waiting for the bandwidth allocation from, the (n + 1)-(n + m) -th packet data having less than the maximum capacity arrives, and then the 1-n-th packet data is transferred by the bandwidth allocation from the station side communication apparatus. At the same time, when it is confirmed that the bandwidth request of the first to n-th packet data has been cleared, the accumulated capacity of the (n + 1) to n + m-th packet data which is less than the maximum capacity is immediately determined as the bandwidth request capacity. Bandwidth requesting method for a point / multipoint bandwidth sharing system. 5. A plurality of subscriber-side communication devices and an office-side communication device are connected in a point-multipoint topology,
Since packet data is transferred between a plurality of subscriber communication devices and a central communication device using a shared band, which is an unused time slot of a transmission frame, the packet data sent from the subscriber terminal is temporarily transmitted to the subscriber terminal. When it is stored in the buffer memory of the communication device on the side and makes a bandwidth request to the communication device on the station side,
The station-side communication device selects a subscriber-side communication device to which a band is to be allocated, and notifies the selected subscriber-side communication device of a bandwidth allocation. A point / multipoint bandwidth sharing system for transferring packet data stored in the station side communication device to the station side communication device, wherein the subscriber side communication device individually manages the capacity of packet data arriving from the subscriber terminal; And a capacity counter for counting the capacity of the arriving packet data and informing the bandwidth request unit for controlling the management table of the arrival of the packet data and the capacity of the packet data. The accumulated value of the packet data up to the first packet is compared with the maximum capacity that can be requested at one time. When the amount exceeds the amount, the accumulated capacity from the first to the nth is determined as the bandwidth request capacity, a bandwidth request is made, and after the value holding the transfer capacity information is cleared, the accumulated capacity is equal to or less than the maximum capacity. However, a point / multipoint bandwidth sharing system characterized by making a bandwidth request.