JP3490583B2 - Dynamic time slot assignment system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic time slot allocation system, and more particularly to a dynamic dynamic time slot in a transmission system in which a subscriber line terminating device allocates a time slot to a terminal device by polling for communication. Allocation method.

[0002]

2. Description of the Related Art FIG. 9 is a conceptual diagram of a conventional system. In the system shown in the figure, two terminal devices 1 # 1 and # 2 exchange information with the subscriber line terminating device 2 via a transmission line. Reference numeral 3 is an upstream transmission path, and 4 is a downstream transmission path.
The number of each terminal device 1 is not limited to the two shown in the figure. In the terminal device 1, reference numeral 1a is a polling wait buffer that waits for information. Reference numeral 4 denotes a downlink transmission line connecting each terminal device 1 and the subscriber line terminating device 2, and the subscriber line terminating device 2 notifies each terminal device 1 of polling via this transmission line 4. . here,
Polling is used to mean an information transmission permission signal.

The subscriber line terminating device 2 polls each terminal device 1 via the transmission line 4, and the terminal device 1 that has received the polling waits for the polling waiting buffer 1a.
If there is information, the information of one time slot is sent to the upstream transmission line 3. The subscriber line terminating device 2 receives the information of one time slot via the transmission line 3.

[0004]

The above-mentioned conventional system has the following problems. In a conventional system, a device (terminal device) that transmits information by polling polls a large amount or the same amount of generated information.

However, this method cannot cope well with the occasional occurrence of bursty traffic such as connection between LANs. If polling is set near the peak rate of information generation, all can be transmitted even if a burst occurs. However, in this method, the polling when the burst is small is all wasted, so that the transmission band cannot be effectively utilized. Therefore, if polling is set near the average value of information generation, a very deep buffer memory is required to absorb fluctuations in the information generation interval.

A method of detecting the occurrence of a call and automatically increasing polling for the call is also conceivable. However, this method has a problem that it cannot be effectively applied when the transmission amount can dynamically change in a path set like a call such as ATM.

The present invention has been made in view of the above problems, and provides a dynamic time slot allocation system capable of efficiently allocating time slots in a system in which the transmission amount dynamically changes. It is an object.

[0008]

[Means for Solving the Problems]

(1) FIG. 1 is a block diagram of the principle of the present invention. The same parts as those in FIG. 9 are designated by the same reference numerals. The system shown in the figure constitutes a communication system in which a plurality of terminal devices 1 and one subscriber line terminating device 2 share one upstream transmission line 3 by polling in a time division manner for transmission. Although one terminal device is shown as the terminal device 1 in the figure, it is assumed that a plurality of terminal devices 1 are actually connected to the transmission path 3.

In the terminal device 1, 5 is a polling wait buffer for holding polling wait information, 10 is a buffer length of the polling wait buffer 5, and the buffer length is compared with a predetermined threshold value. Polling request generation means for generating a polling request according to
A multiplexing unit 6 multiplexes the output of the polling waiting buffer 5 and the output of the polling request generating means 10 and sends them to the transmission line 3. Another terminal device 1 is provided on the transmission line 3.
The transmission line from is also connected.

In the subscriber line terminating device 2, 7 is a polling request identification unit for identifying a polling request sent from the terminal device 1 through the transmission line 3, and 8 is a minimum guarantee for generating a minimum guarantee polling. Polling generator, 9
Is a shared bandwidth control unit that receives the output of the minimum guaranteed polling generation unit 8 and the output of the polling request identification unit 7 and allocates a time slot to a free space of the minimum guaranteed polling according to the amount of polling waiting information. . The output of the shared band control unit 9 is given to each terminal device 1 as polling via the downlink transmission line 4. The transmission line 4 is also connected to another terminal device 1 (not shown).

According to the structure of the present invention, the polling request generating means 10 generates a polling request according to the information waiting state of the polling waiting buffer 5 and notifies it to the subscriber line terminating device 2 side via the transmission line 3. On the subscriber line terminating device 2 side, the sent polling request is analyzed, and the shared bandwidth control unit 9 sets the polling pattern in the polling free area generated by the minimum guaranteed polling generating unit 8 in response to the polling request. Can be put in. Since this polling pattern is notified to each terminal device 1 via the transmission path 4, it is possible to dynamically and efficiently allocate time slots in the entire system.

(2) In this case, the polling request generating means 10 compares the amount of information waiting in the polling waiting buffer 5 with a predetermined threshold value,
Information about whether the amount of waiting information is larger or smaller than a predetermined threshold is notified to the subscriber line terminating device 2 via the multiplexing unit 6 as a polling request, and the subscriber line terminating device 2 uses the received polling information. It is characterized by changing the polling pattern.

According to the configuration of the present invention, the amount of information waiting in the polling waiting buffer 5 is compared with a predetermined threshold value, and a polling request is made for information indicating whether the waiting information amount is larger or smaller than the predetermined threshold value. The subscriber line terminating device 2 can be notified to the subscriber line terminating device 2 via the multiplexing unit 6 as described above. Therefore, the subscriber line terminating device 2 can dynamically change the polling pattern in response to the polling request, and the time slot can be set for the entire system. Can be dynamically and efficiently assigned.

(3) Further, the polling request generation means 10 compares the amount of information waiting in the polling waiting buffer 5 with a plurality of threshold values, and the threshold value of the amount of waiting information exceeds which threshold value. The subscriber line terminating device 2 is notified via the multiplexing unit 6 of the information indicating whether the subscriber line terminating device 2 is in the open state.
Is characterized by changing the polling pattern according to the received polling information.

According to the configuration of the present invention, since the polling request state on the terminal device 1 side can be recognized more finely on the subscriber line terminating device 2 side, the subscriber line terminating device 2 more finely and dynamically allocates time slots. Can be done efficiently.

(4) Further, it is characterized in that a polling request is inserted for each piece of information transmitted from the terminal device 1 and transferred to the subscriber line terminating device 2. According to the configuration of the present invention, it is possible to insert a polling request into the header portion for each information unit transmitted from the terminal device 1 to notify the subscriber line terminating device 2 side.
The side can grasp the polling waiting state of the corresponding terminal device 1.

(5) Further, it is characterized in that a polling request is inserted for each supervisory control information periodically sent from the terminal device 1 and transferred to the subscriber line terminating device 2. According to the configuration of the present invention, it is possible to insert a polling request for each periodically generated supervisory control information and notify the subscriber line terminating device 2 side.
It is possible to grasp the polling waiting state of the corresponding terminal device 1.

(6) Further, the polling waiting buffer 5 is provided for each service class, and the polling request generating means 10 determines the priority if the polling waiting buffer 5 of the service class having a high priority remains. In the case of a service class having a low priority, the polling request generating means 10 generates a polling request in the case of a service class having a low priority, and the polling request is generated in accordance with the amount of information in the polling waiting buffer 5. It is characterized by performing time slot allocation.

According to the configuration of the present invention, the polling wait information of the service class with a high priority is promptly sent to the transmission line 3, and in the case of the service class with a low priority, the polling wait information is determined according to the amount of the polling wait buffer. By changing the polling pattern, efficient time slot allocation can be performed according to the difference in priority.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 2 is an operation explanatory diagram of the first embodiment of the present invention. The same thing as in Figure 1
The same reference numerals are given. In the figure, an example is shown in which one terminal device 1 and one subscriber line terminating device 2 are connected via transmission lines 3 and 4, but a plurality of terminal devices 1 are actually connected. . Although not shown, a user terminal device is connected to the terminal device 1.

In the terminal device 1, 5 is a polling wait buffer, and 6 is a multiplexer for receiving the output of the polling wait buffer 5 and multiplexing information. Reference numeral 11 is a buffer length detection unit that detects the buffer length of the polling wait information accumulated in the polling wait buffer 5, 12 is a predetermined buffer length threshold, and the buffer length detected by the buffer length detection unit 11. A threshold value processing unit for comparing with and a reference numeral 13 is a polling request generation unit for receiving the output of the threshold value processing unit 12 and generating a polling request. The output of the polling request generator 13 is input to the other input of the multiplexer 6. Then, the buffer length detection unit 1
1, the threshold value processing unit 12 and the polling request generating unit 13 constitute the polling request generating means 10 of FIG.

In the subscriber line terminating device 2, a polling request 7 receives the time slot information transmitted from the multiplexer 6 of the terminal device 1 via the transmission path 3 and identifies whether or not the polling request is included. An identification unit, 8 is a minimum guaranteed polling generation unit that generates the minimum guaranteed polling determined by the system, and 9 is a polling request identification unit 7
And the output of the minimum guaranteed polling generator 8
It is a shared bandwidth control unit that allocates time slots to a polling free area generated by the minimum guaranteed polling generation unit according to the amount of polling waiting information. Polling request identification information is output from the polling request identification unit 7 and notified to other sections. The operation of the system configured as described above will be described below.

In the terminal device 1, the buffer length detecting unit 11 detects the buffer length of the information waiting in the polling waiting buffer 5, and notifies the threshold processing unit 12 of it. The threshold processing unit 12 determines whether the buffer length exceeds the threshold and notifies the polling request generation unit 13 of the determination result. Here, the threshold is a value that is predetermined by the system and cannot be changed by the user.

The polling request generator 13 encodes the result determined by the threshold processor 12 and notifies the multiplexer 6 of the encoded result. The multiplexing unit 6 reads one time slot 20 from the polling waiting buffer 5, multiplexes the determination result with information, and sends the multiplexed result to the upstream transmission path 3. Here, the polling request is included in the overhead.

The signal shown in the figure shows the signal state on the upstream transmission line 3 in the figure. 20 is a time slot (information unit) transmitted on the transmission line 3 to the subscriber line terminating device 2 side.
Is. The time slot 20 is composed of information 20a and an overhead 20b.
A polling request is put in b. Here, the polling request 20 put in the overhead 20b
c is the polling wait buffer length is greater than the threshold,
This is information indicating whether it is smaller than the threshold value.

On the side of the subscriber line terminating device 2, the polling request identification unit 7 receives the time slot 20 transmitted via the upstream transmission line 3 and identifies whether or not the polling request 20c is included in the overhead 20b. . Then, when the polling request 20c is included, it is determined whether or not the polling waiting buffer length exceeds the threshold value. The polling request identification unit 7 notifies the shared bandwidth control unit 9 of information as to whether the polling waiting buffer length exceeds the threshold value.

On the other hand, in the minimum guaranteed polling generator 8,
A polling signal corresponding to the minimum guaranteed amount determined in advance by the system is generated and passed to the shared band control unit 9.
The minimum guaranteed polling at this time is as shown in the figure. In the example shown in the figure, it can be seen that polling of terminal 1, terminal 2, terminal 3, and terminal 4 occurs after a predetermined period. Polling corresponding to the time slot that has not been used in the minimum guaranteed polling is passed to the shared bandwidth control unit 9 as an empty space.

The shared bandwidth control section 9 receives the polling signal from the minimum guaranteed polling generation section 8, searches for an empty area, and when a free area is found, the polling waiting buffer length exceeds the threshold value. The empty area is sequentially replaced by the polling signal of.

On the downlink transmission line 4 in the figure is a polling signal notified from the shared band control unit 9 to the terminal device 1.
Here, the case where the terminal 2 and the terminal 3 exceed the threshold value is shown. As a result, the shared bandwidth control unit 9 evenly allocates the terminals 2 and 3 to the empty area of the polling signal. Therefore, it can be seen that the terminal 2 and the terminal 3 are alternately inserted in the empty area of the polling signal as shown in the figure.

According to this embodiment, the amount of information waiting in the polling waiting buffer 5 is compared with a predetermined threshold value, and information about whether the waiting information amount is larger or smaller than the predetermined threshold value is polled. Multiplexer 6 as a request
The subscriber line terminating device 2 can dynamically change the polling pattern in response to the polling request because the subscriber line 2 can be notified via the call, and the system as a whole can dynamically and efficiently allocate the time slots. Can be done.

FIG. 3 is an operation explanatory diagram of the second embodiment of the present invention. The same parts as those in FIG. 2 are designated by the same reference numerals. In the figure, 12a is a threshold value processing unit for comparing the output of the buffer length detection unit 11 with a plurality of threshold values. In the example shown in the figure, a plurality of thresholds 1 to 4 are input to the threshold processing unit 12a, the threshold processing unit 12a compares the polling waiting buffer length with these plural thresholds, and the polling waiting buffer length is determined. It is designed to determine whether or not it is within the threshold range. The number of thresholds is 4 as shown in the figure.
The number is not limited to one, and may be any number. Other configurations are the same as those in FIG. The operation of the system configured as described above will be described below.

In the terminal device 1, the buffer length detecting unit 11 detects the buffer length waiting for polling, and the threshold processing unit 12
Notify a. The threshold processing unit 12a receives the output of the buffer length detection unit 11, determines whether the buffer length exceeds each threshold value, and notifies the polling request generation unit 13 of the determination result.

The polling request generation unit 13 encodes the results based on the plurality of determination results determined by the threshold value processing unit 12a and notifies the multiplexing unit 6 of the encoded results. The multiplexing unit 6 reads one time slot 20 from the polling waiting buffer 5,
Polling information is put in the overhead, multiplexed with the information, and sent to the upstream transmission line 3. Here, the polling request is put in the overhead 20b of the time slot 20.

The signal shown in the figure shows the signal state on the upstream transmission line 3 in the figure. Here, the overhead 20b
The polling information 20c put in is information indicating which threshold value the polling waiting buffer length exceeds.

On the side of the subscriber line terminating device 2, the polling request identification unit 7 receives the time slot 20 transmitted via the upstream transmission line 3 and identifies whether or not the polling request 20c is included in the overhead 20b. . Then, when the polling request 20c is included, it is identified which threshold the polling waiting buffer length exceeds. The polling request identification unit 7 notifies the shared bandwidth control unit 9 of information indicating which threshold the polling waiting buffer length exceeds.

On the other hand, in the minimum guaranteed polling generator 8,
A polling signal corresponding to the minimum guaranteed amount determined in advance by the system is generated and passed to the shared band control unit 9.
The minimum guaranteed polling at this time is as shown in the figure. In the example shown in the figure, it can be seen that polling of terminal 1, terminal 2, terminal 3, and terminal 4 occurs after a predetermined period. Polling corresponding to the time slot that has not been used in the minimum guaranteed polling is passed to the shared bandwidth control unit 9 as an empty space.

The shared bandwidth control unit 9 receives the polling signal from the minimum guaranteed polling generation unit 8, searches for a vacant portion, and when a vacant area is found, a threshold value whose buffer length is small based on the first vacant area. Replace with the polling signal of the terminal device that exceeds the limit. When the number of terminal devices that exceed the threshold that is also smaller than the threshold is N1 cycles, replace with the polling signal of the terminal device that exceeds the second smallest threshold,
If this is N2 cycles, it is replaced with the polling signal of the terminal device that exceeds the third smallest threshold value. After Nn cycles of the terminal devices that have exceeded the maximum threshold value, the process returns to the terminal devices that have exceeded the minimum threshold value.

On the downlink transmission line 4 in the figure is a polling signal notified from the shared band control unit 9 to the terminal device 1.
Here, the case where the terminal 2 exceeds the smallest threshold value, the terminal 3 exceeds the second smallest threshold value, and N1 = 3 and N2 = 5 is shown. That is, at the beginning of the free space, the terminals 2 and 3 that have exceeded the smallest threshold are assigned. When the terminal 2 and the terminal 3 repeat three times, this time, the polling signal of the terminal device that exceeds the second smallest threshold value is replaced and five cycles are performed. Since only the terminal 3 is the terminal device that has exceeded the second smallest threshold value, the terminal 3 is allocated five times. As a result, the allocation of the terminal device in the empty area is shown in the figure (only the number is shown) 232323.
33333.

According to this embodiment, the polling request state on the side of the terminal device 1 is further detailed and the subscriber line terminating device 2
Since it can be recognized on the side, the subscriber line terminating device 2 can perform time slot allocation more finely dynamically and efficiently.

FIG. 4 is an operation explanatory view of the third embodiment of the present invention. The same parts as those in FIG. 2 are designated by the same reference numerals. In this embodiment, the buffer length of the polling waiting buffer 5 is not compared with a threshold value, but the buffer length itself is put into a time slot and transmitted to the subscriber line terminating device 2 side. The operation of the system configured as described above will be described below.

In the terminal device 1, the buffer length detector 11 detects the buffer length of the information waiting in the polling wait buffer 5, and notifies the polling request generator 13 of the buffer length. The polling request generation unit 13 encodes the buffer length detected by the buffer length detection unit 11 and multiplexes it by the multiplexing unit 6.
To notify. The multiplexing unit 6 reads one time slot 20 from the polling waiting buffer 5, puts the buffer length into the overhead 20b of the time slot 20, multiplexes it with information, and sends it to the upstream transmission line 3.

The signal shown in the figure shows the signal state on the upstream transmission line 3 in the figure. 20 is a time slot (information unit) transmitted on the transmission line 3 to the subscriber line terminating device 2 side.
Is. The time slot 20 is composed of information 20a and an overhead 20b.
Polling information 20c is inserted in b. Here, the polling information 20c put in the overhead 20b is the polling waiting buffer length.

On the side of the subscriber line terminating device 2, the polling request identification unit 7 receives the time slot 20 transmitted via the upstream transmission line 3 and identifies whether or not the overhead 20b contains a polling request. When the polling request 20c is included, the polling waiting buffer length is extracted and notified to the shared bandwidth control unit 9.

On the other hand, in the minimum guaranteed polling generator 8,
A polling signal corresponding to the minimum guaranteed amount determined in advance by the system is generated and passed to the shared band control unit 9.
The minimum guaranteed polling at this time is as shown in the figure. In the example shown in the figure, it can be seen that polling of terminal 1, terminal 2, terminal 3, and terminal 4 occurs after a predetermined period. Polling corresponding to the time slot that has not been used in the minimum guaranteed polling is passed to the shared bandwidth control unit 9 as an empty space.

The shared bandwidth control unit 9 receives the polling signal from the minimum guaranteed polling generation unit 8, searches for an empty portion, and when a free area is found, the buffer length exceeds 1 for the first empty area. Replace with the polling signal of the terminal device that is installed. When the terminal device whose buffer length exceeds 1 makes one round of allocation, this time the buffer length becomes 2
Replace with the polling signal of the terminal device that exceeds the limit.
When the terminal device having the buffer length exceeding 2 makes one round of allocation, this time, it is replaced with the polling signal of the terminal device having the buffer length exceeding 3. By repeating this, when there is no terminal device having a buffer length exceeding N, the process is returned to the terminal device having a buffer length exceeding 1 again.

On the downlink transmission line 4 in the figure is a polling signal notified from the shared band control unit 9 to the terminal device 1.
Here, the case where the terminal 2 has a buffer length of 2, the terminal 3 has a buffer length of 6, and the others have a buffer length of 0 is shown. As a result,
The shared bandwidth control unit 9 first allocates the terminals 2 and 3 which are terminal devices whose buffer length exceeds 1. Next, terminals 2 and 3 which are terminal devices having a buffer length of more than 2 are allocated.

Next, terminal 3 which is a terminal device having a buffer length of more than 3 is assigned. Next, the terminal 3, which is a terminal device having a buffer length of more than 4, is assigned. Next, the terminal 3, which is a terminal device having a buffer length of more than 5, is assigned. Next, the terminal 3, which is a terminal device having a buffer length exceeding 6, is assigned.

Then, returning to the beginning, the same operation is repeated. As a result, as shown in the figure (only numbers are shown), the allocation of the terminal devices in the empty area is 23233333323.
Becomes

According to this embodiment, the amount of information waiting in the polling waiting buffer 5 is calculated, and this information can be notified to the subscriber line 2 via the multiplexer 6 as a polling request. Therefore, the subscriber line terminating device 2 can dynamically change the polling pattern in response to the polling request, and the time slot can be dynamically and efficiently allocated in the entire system.

According to the embodiment described above, the polling request is inserted for each piece of information sent from the terminal device 1 and transferred to the subscriber line terminating device 2, whereby the information sent from the terminal device 1 is transmitted. For example, a polling request can be inserted in the header portion for each unit to notify the subscriber line terminating device 2 side, and the subscriber line terminating device 2 side can grasp the polling waiting state of the corresponding terminal device 1. .

FIG. 5 is a diagram for explaining the operation of the fourth embodiment of the present invention. The same parts as those in FIG. 2 are designated by the same reference numerals. In this embodiment, a polling request is included in the supervisory control information that is periodically transmitted from the terminal device 1 side to the subscriber line terminating device 2 side with the transmission of the time slot, and is transmitted. . The supervisory control information is for transmitting the above-mentioned power failure of the user terminal device and other information from the terminal device 1 to the subscriber line terminating device 2 side at each cycle defined by the timer. The system configuration is the same as in FIG. The operation of the system configured as described above will be described below.

In the terminal device 1, the buffer length detecting unit 11 detects the buffer length of the information waiting in the polling waiting buffer 5, and notifies the threshold processing unit 12 of it. The threshold processing unit 12 determines whether the buffer length exceeds the threshold and notifies the polling request generation unit 13 of the determination result.

The polling request generator 13 encodes the result determined by the threshold processor 12 and notifies the multiplexer 6 of the result. The multiplexing unit 6 inserts a polling request into the periodically generated supervisory control information, multiplexes it, and sends it to the upstream transmission path 3. Here, the polling request is put in the information area of the monitor control information. The polling request is put in the information area in the supervisory control information because the transmission efficiency of the information is better than putting the polling request in the overhead.

The signal shown in the figure shows the signal state on the upstream transmission line 3 in the figure. 20 is a time slot (information unit) transmitted on the transmission line 3 to the subscriber line terminating device 2 side.
Is. This time slot 20 is composed of information 20a and overhead 20b. Reference numeral 21 is supervisory control information that is periodically sent out on the transmission path 3, and is composed of an information area and an overhead. Reference numeral 21a is a polling request entered in the information area. Here, the polling request 21a entered in the information area is information indicating whether the polling waiting buffer length is larger than the threshold value or smaller than the threshold value.

On the subscriber line terminating device 2 side, the polling request identification unit 7 receives the supervisory control information 21 transmitted via the upstream transmission line 3, and polls the request 21a in the information area.
Identify whether or not Then, when the polling request 21a is included, it is identified whether or not the polling waiting buffer length exceeds the threshold value. The polling request identification unit 7 notifies the shared bandwidth control unit 9 of information as to whether the polling waiting buffer length exceeds the threshold value.

On the other hand, in the minimum guaranteed polling generator 8,
A polling signal corresponding to the minimum guaranteed amount determined in advance by the system is generated and passed to the shared band control unit 9.
The minimum guaranteed polling at this time is as shown in the figure. In the example shown in the figure, it can be seen that polling of terminal 1, terminal 2, terminal 3, and terminal 4 occurs after a predetermined period. Polling corresponding to the time slot that has not been used in the minimum guaranteed polling is passed to the shared bandwidth control unit 9 as an empty space.

The shared bandwidth control unit 9 receives the polling signal from the minimum guaranteed polling generation unit 8, searches for an empty portion, and when a free area is found, the polling waiting buffer length exceeds the threshold value. The empty area is sequentially replaced by the polling signal of.

On the downlink transmission line 4 in the figure is a polling signal notified from the shared band control unit 9 to the terminal device 1.
Here, the case where the terminal 2 and the terminal 3 exceed the threshold value is shown. As a result, the shared bandwidth control unit 9 evenly allocates the terminals 2 and 3 to the empty area of the polling signal. Therefore, it can be seen that the terminal 2 and the terminal 3 are alternately inserted in the empty area of the polling signal as shown in the figure. Specifically, when only the numbers indicating the terminals are used, the terminal devices are allocated to 23232323323 and the time slots are allocated to the empty areas as shown in the figure (only the numbers are shown).

According to this embodiment, it is possible to insert a polling request for each supervisory control information that occurs periodically to notify the subscriber line terminating device 2 side. It is possible to grasp the polling waiting state of the corresponding terminal device 1.

FIG. 6 is a diagram for explaining the operation of the fifth embodiment of the present invention. The same parts as those in FIGS. 3 and 5 are designated by the same reference numerals. This embodiment is the fourth embodiment shown in FIG. 5 and is provided with a plurality of threshold values. 12a
Is a threshold processing unit that compares the buffer length detected by the buffer length detection unit 11 with a plurality of thresholds. The example shown in the figure
A plurality of thresholds 1 to 4 are input to the threshold processing unit 12a, and the threshold processing unit 12a compares the polling waiting buffer length with the plurality of thresholds to determine which threshold range the polling waiting buffer length is in. Is determined. The number of thresholds is not limited to four as shown in the figure, and may be any number. The operation of the system configured as described above will be described below.

In the terminal device 1, the buffer length detection unit 11 detects the buffer length waiting for polling, and the threshold value processing unit 12
Notify a. The threshold processing unit 12a receives the output of the buffer length detection unit 11, determines whether the buffer length exceeds each threshold value, and notifies the polling request generation unit 13 of the determination result.

The polling request generation unit 13 encodes the results based on the plurality of determination results determined by the threshold processing unit 12a and notifies the multiplexing unit 6 of the encoded results. The multiplexing unit 6 uses the monitoring control information 2
When 1 is generated, polling information is put in the information area, multiplexed, and sent to the upstream transmission line 3.

The signal shown in the figure shows the signal state on the upstream transmission line 3 in the figure. A time slot (information unit) 20 is transmitted on the transmission line 3 to the subscriber line terminating device 2 side. This time slot 20 is composed of information 20a and overhead 20b. Reference numeral 21 is supervisory control information that is periodically sent out on the transmission path 3, and is composed of an information area and an overhead. Reference numeral 21a is a polling request entered in the information area. Here, the polling request 21a entered into the information area is information indicating which threshold exceeds the polling waiting buffer length.

On the side of the subscriber line terminating device 2, the polling request identification unit 7 receives the supervisory control information 21 transmitted via the upstream transmission line 3, and polls the request 21a in the information area.
Identify whether or not Then, when the polling request is included, it is identified which threshold exceeds the polling waiting buffer length. The polling request identification unit 7 notifies the shared bandwidth control unit 9 of information indicating which threshold the polling waiting buffer length exceeds.

On the other hand, in the minimum guaranteed polling generator 8,
A polling signal corresponding to the minimum guaranteed amount determined in advance by the system is generated and passed to the shared band control unit 9.
The minimum guaranteed polling at this time is as shown in the figure. In the example shown in the figure, it can be seen that polling of terminal 1, terminal 2, terminal 3, and terminal 4 occurs after a predetermined period. Polling corresponding to the time slot that has not been used in the minimum guaranteed polling is passed to the shared bandwidth control unit 9 as an empty space.

The shared bandwidth control unit 9 receives the polling signal from the minimum guaranteed polling generation unit 8, searches for a vacant portion, and when a vacant area is found, a threshold value having a small buffer length for the first vacant area. Replace with the polling signal of the terminal device that exceeds the limit. If the number of terminal devices that exceed the threshold is smaller than N1, the terminal signal that exceeds the second smallest threshold value is replaced with the polling signal of the terminal device. . After Nn cycles of the terminal devices that have exceeded the maximum threshold value, the process returns to the terminal devices that have exceeded the minimum threshold value.

On the downlink transmission line 4 in the figure is a polling signal notified from the shared band control unit 9 to the terminal device 1.
Here, the case where the terminal 2 exceeds the smallest threshold value, the terminal 3 exceeds the second smallest threshold value, and N1 = 3 and N2 = 5 is shown. That is, at the beginning of the free space, the terminals 2 and 3 that have exceeded the smallest threshold are assigned. When the terminal 2 and the terminal 3 repeat three times, this time, the polling signal of the terminal device that exceeds the second smallest threshold value is replaced and five cycles are performed. Since only the terminal 3 is the terminal device that has exceeded the second smallest threshold value, the terminal 3 is allocated five times. As a result, the allocation of the terminal device in the empty area is shown in the figure (only the number is shown) 232323.
33333.

According to this embodiment, the polling request state on the terminal device 1 side is further detailed and the subscriber line terminating device 2
Since it can be recognized on the side, the subscriber line terminating device 2 can perform time slot allocation more finely dynamically and efficiently.

FIG. 7 is an operation explanatory view showing the sixth embodiment of the present invention. The same parts as those in FIGS. 4 and 5 are designated by the same reference numerals. In this embodiment, the polling wait buffer length information in the embodiment shown in FIG.
The monitor control information 21 is inserted and transmitted. The configuration is the same as that in FIG. The operation of the system configured as described above will be described below.

In the terminal device 1, the buffer length detector 11 detects the buffer length of the information waiting in the polling wait buffer 5, and notifies the polling request generator 13 of the buffer length. The polling request generation unit 13 encodes the buffer length detected by the buffer length detection unit 11 and multiplexes it by the multiplexing unit 6.
To notify. When generating the monitoring control information, the multiplexing unit 6 puts the polling request 21a indicating the buffer length in the information area of the monitoring control information 21, multiplexes it with the information, and sends it to the upstream transmission line 3.

The signal shown in the figure shows the signal state on the upstream transmission line 3 in the figure. 20 is a time slot (information unit) transmitted on the transmission line 3 to the subscriber line terminating device 2 side.
Is. This time slot 20 is composed of information 20a and overhead 20b. Reference numeral 21 is supervisory control information that is periodically generated. In the monitor control information 21, 21a is a polling request put in the information area. The polling request 21a is information indicating the buffer length of the polling waiting buffer.

On the side of the subscriber line terminating device 2, the polling request identification unit 7 receives the supervisory control information 21 transmitted via the upstream transmission line 3, and polls the request 21a in the information area.
Identify whether or not If the polling request 21a is included, the polling waiting buffer length is extracted and notified to the shared bandwidth control unit 9.

On the other hand, in the minimum guaranteed polling generator 8,
A polling signal corresponding to the minimum guaranteed amount determined in advance by the system is generated and passed to the shared band control unit 9.
The minimum guaranteed polling at this time is as shown in the figure. In the example shown in the figure, it can be seen that polling of terminal 1, terminal 2, terminal 3, and terminal 4 occurs after a predetermined period. Polling corresponding to the time slot that has not been used in the minimum guaranteed polling is passed to the shared bandwidth control unit 9 as an empty space.

The shared bandwidth control unit 9 receives the polling signal from the minimum guaranteed polling generation unit 8, searches for an empty portion, and when a free area is found, the buffer length exceeds 1 for the first free space. Replace with the polling signal of the terminal device that is installed. When the terminal device whose buffer length exceeds 1 makes one round of allocation, this time the buffer length becomes 2
Replace with the polling signal of the terminal device that exceeds the limit.
When the terminal device having the buffer length exceeding 2 makes one round of allocation, this time, it is replaced with the polling signal of the terminal device having the buffer length exceeding 3. By repeating this, when there is no terminal device having a buffer length exceeding N, the process is returned to the terminal device having a buffer length exceeding 1 again.

On the downlink transmission line 4 in the figure is a polling signal notified from the shared band control unit 9 to the terminal device 1.
Here, the case where the terminal 2 has a buffer length of 2, the terminal 3 has a buffer length of 6, and the others have a buffer length of 0 is shown. As a result,
The shared bandwidth control unit 9 first allocates the terminals 2 and 3 which are terminal devices whose buffer length exceeds 1. Next, terminals 2 and 3 which are terminal devices having a buffer length of more than 2 are allocated.

Next, terminal 3 which is a terminal device having a buffer length of more than 3 is assigned. Next, the terminal 3, which is a terminal device having a buffer length of more than 4, is assigned. Next, the terminal 3, which is a terminal device having a buffer length of more than 5, is assigned. Next, the terminal 3, which is a terminal device having a buffer length exceeding 6, is assigned.

Next, returning to the beginning, the same operation is repeated. As a result, as shown in the figure (only numbers are shown), the allocation of the terminal devices in the empty area is 23233333323.
Becomes

According to this embodiment, the amount of information waiting in the polling waiting buffer 5 is obtained, and this information can be notified to the subscriber line 2 via the multiplexer 6 as a polling request. Therefore, the subscriber line terminating device 2 can dynamically change the polling pattern in response to the polling request, and the time slot can be dynamically and efficiently allocated in the entire system.

FIG. 8 is an operation explanatory diagram of the seventh embodiment of the present invention. The same parts as those in FIG. 2 are designated by the same reference numerals. In this embodiment, a polling wait buffer is provided for each service class. In the figure, 5a
Is a first polling wait buffer that holds high priority information, and 5b is a second polling wait buffer that holds low priority information. A priority read control unit 14 receives the outputs of these polling wait buffers 5a and 5b and performs priority read control. The output of the priority read control unit 14 is input to the multiplexing unit 6. The buffer length of the polling waiting buffer 5b that holds low priority information is input to the buffer length detection unit 11. Although the figure shows a case where two polling waiting buffers 5a and 5b are provided, the number may be arbitrary. Other configurations are the same as those in FIG. The operation of the system configured as described above will be described below.

In the terminal device 1, the buffer length detecting unit 11 detects the buffer length of the service class having the low priority and notifies the threshold value processing unit 12 of it. The threshold processing unit 12 determines whether or not the buffer length of the polling waiting buffer 5b exceeds a predetermined threshold. The determination result is sent to the polling request generator 13.

The polling request generator 13 encodes information on whether or not the buffer length exceeds a predetermined threshold and notifies the multiplexer 6 of the information. The multiplexing unit 6 multiplexes the information output from the priority read control unit 14 and the polling request,
Transmission is performed via the upstream transmission line 3 as shown on the subscriber line terminating device 2 side. In the illustrated example, the polling request 20c is inserted in the overhead 20b of the time slot 20.

The signal shown in the figure shows the signal state on the upstream transmission line 3 in the figure. 20 is a time slot (information unit) transmitted on the transmission line 3 to the subscriber line terminating device 2 side.
Is. This time slot 20 is composed of information 20a and overhead 20b. Polling request 2 that is information indicating the buffer length of the polling waiting buffer
1c is put in the overhead 20b of the time slot 20.

In this case, the priority read control unit 1
4 receives the outputs of both the polling wait buffers 5a and 5b, and if information remains in the polling wait buffer 5a that holds high priority information, it reads the time slot from the polling wait buffer 5a and gives priority. When the information is sent to the transmission line 3 and no information remains in the polling waiting buffer 5a, the information of the polling waiting buffer 5b holding the low priority information is read out and the transmission line 3 is read.
Priority control such as sending to

On the side of the subscriber line terminating device 2, the polling request identification unit 7 identifies whether or not the polling request 20c is included in the time slot 20 sent via the transmission path 3, and it is included. In this case, it is determined whether the buffer length exceeds the threshold. Then, the polling request identification unit 7 identifies the polling request, and when the buffer length exceeds the threshold value, the shared band control unit 9 is notified of the information.

On the other hand, in the minimum guaranteed polling generator 8,
Polling information as shown in the figure is generated. Here, the minimum guaranteed polling generation unit 8 specifically generates a polling signal corresponding to the minimum guaranteed polling amount sufficient to transmit information of a preset service class having a high priority, and controls the shared bandwidth. Notify Part 9. The minimum guaranteed polling at this time is, in the example shown in FIG.
It can be seen that the polling of terminal 2, terminal 3, and terminal 4 occurs after a predetermined period.

In this case, the polling corresponding to the time slot not used in the minimum guaranteed polling is notified to the shared bandwidth control unit 9 as an empty space. The shared band control unit 9 receives the polling signal from the minimum guaranteed polling generation unit 8 and searches for an empty area,
When a free space is found, the free space is sequentially replaced by the polling signal of the terminal device 1 whose buffer length exceeds the threshold value.

In the figure, the polling information notified by the shared band control unit 9 to each terminal device 1 in this way is shown. Here, the case where the terminal 2 and the terminal 3 exceed the threshold value is shown. As a result, the shared bandwidth control unit 9
The terminals 2 and 3 are evenly allocated to the empty area of the polling signal. Therefore, it can be seen that the terminal 2 and the terminal 3 are alternately inserted in the empty area of the polling signal as shown in the figure.

According to this embodiment, the polling wait information of the service class with a high priority is promptly sent to the transmission line 3, and in the case of the service class with a low priority, the polling wait information depends on the amount of the polling wait buffer. By changing the polling pattern, it is possible to allocate time slots efficiently according to the difference in priority.

[0089]

As described above in detail, according to the present invention, (1) a plurality of terminal devices and one subscriber line terminating device share one transmission line by polling in time division and transmit. In the communication system performing the above, the terminal device detects a polling wait buffer that holds polling wait information and the buffer length of the polling wait buffer, compares the buffer length with a predetermined threshold, and compares the result. The polling request generating means for generating a polling request in response to the polling request, and a multiplexing section for multiplexing the output of the polling waiting buffer and the output of the polling request generating means and transmitting the multiplexed signal to the transmission line. The terminating device generates a polling request identification section for identifying a polling request sent from the terminal device sent through the transmission line, and a minimum guaranteed polling. A minimum guaranteed polling generator, an output of the minimum guaranteed polling generator, and an output of the polling request identification unit, and time slots are allocated to a free space of the minimum guaranteed polling in accordance with the amount of polling wait information. By including the bandwidth control unit, the polling request generation unit generates a polling request according to the information waiting state of the polling waiting buffer and notifies the subscriber line terminating device side via the transmission line to terminate the subscriber line termination. On the device side, the sent polling request can be analyzed, and the shared band control unit can insert the polling pattern into the free space for polling generated by the minimum guaranteed polling generation unit in response to the polling request. Since this polling pattern is notified to each terminal device 1 via the transmission path 4, it is possible to dynamically and efficiently allocate time slots in the entire system.

(2) In this case, the polling request generating means compares the amount of information waiting in the polling waiting buffer 5 with a predetermined threshold value, and the waiting information amount is larger or smaller than the predetermined threshold value. This information is sent as a polling request to the subscriber line terminating device via the multiplexing unit, and the subscriber line terminating device waits in the polling waiting buffer by changing the polling pattern according to the received polling information. Since it is possible to compare the amount of information being held with a predetermined threshold and notify the subscriber line terminating device via the multiplexing unit of the information as to whether the amount of waiting information is larger or smaller than the predetermined threshold as a polling request. , The subscriber line terminating equipment can dynamically change the polling pattern according to the polling request. Overall allocation of time slots can be performed dynamically efficiently.

(3) Further, the polling request generating means compares the amount of information waiting in the polling waiting buffer 5 with a plurality of thresholds, and the threshold of the amount of information waiting is exceeded. The information indicating whether or not the status is present is sent as a polling request to the subscriber line terminating device via the multiplexing unit, and the subscriber line terminating device changes the polling pattern according to the received polling information, so that the terminal device side Since the polling request status can be recognized more finely on the side of the subscriber line terminating device, the subscriber line terminating device can perform the time slot allocation more dynamically and efficiently.

(4) Further, by inserting a polling request for each piece of information sent from the terminal device and transferring the polling request to the subscriber line terminating device, for example, a header portion is polled for each information unit sent from the terminal device. The request can be inserted and notified to the subscriber line terminating device side, and the subscriber line terminating device side can grasp the polling waiting state of the corresponding terminal device.

(5) Further, by inserting a polling request for each supervisory control information periodically sent from the terminal device and transferring the polling request to the subscriber line terminating device, each supervisory control information periodically generated. The polling request can be inserted and notified to the subscriber line terminating device side, and the subscriber line terminating device can grasp the polling waiting state of the corresponding terminal device.

(6) Further, the polling waiting buffer is provided for each service class, and the polling request generating means has a high priority buffer if information remains in the polling waiting buffer of the service class having a high priority. The priority control for sending information from the polling request is performed, and in the case of a service class with a low priority, the polling request is generated by sharing the bandwidth and the polling request generation means generates the time slot allocation according to the amount of information in the polling waiting buffer. By doing so, the polling wait information of the service class with high priority is promptly sent to the transmission line, and in the case of the service class with low priority, the polling pattern is changed according to the amount of the polling wait buffer. Efficient time slot allocation according to different priorities Ukoto can.

As described above, according to the present invention, it is possible to provide a dynamic time slot allocation system capable of efficiently allocating time slots in a system in which the transmission amount dynamically changes.

[Brief description of drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is an operation explanatory diagram of the first embodiment example of the present invention.

FIG. 3 is an operation explanatory view of the second embodiment example of the present invention.

FIG. 4 is an operation explanatory view of the third embodiment example of the present invention.

FIG. 5 is an operation explanatory diagram of the fourth embodiment of the present invention.

FIG. 6 is an operation explanatory diagram of the fifth embodiment of the present invention.

FIG. 7 is an operation explanatory diagram of the sixth embodiment of the present invention.

FIG. 8 is an operation explanatory diagram of the seventh embodiment of the present invention.

FIG. 9 is a conceptual diagram of a conventional system.

[Explanation of symbols]

1 terminal device 2 Subscriber line terminator 3 transmission lines 4 transmission lines 5 Polling wait buffer 6 Multiplexing unit 7 Polling request identification section 8 Minimum guarantee polling generator 9 Shared bandwidth controller 10 Polling request generating means

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuyuki Tajima 4-1-1 Kamitadanaka, Nakahara-ku, Kawasaki, Kanagawa Prefecture Fujitsu Limited (72) Inventor Setsuo Aburi 4-chome, Ueodaanaka, Nakahara-ku, Kawasaki, Kanagawa No. 1 in Fujitsu Limited (72) Inventor Michio Kusanagi 4-1-1 Kamiodadanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture 1-1 1-1 Masaki Hirota Inventor (72) Inc. 4-1, Ueda-anaka, Nakahara-ku, Kawasaki, Kanagawa No. 1 in Fujitsu Limited (72) Haruo Yamashita Inventor Haruo Yamashita 4-1-1 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Within Fujitsu Limited (72) Yoshio Kajiyama 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo No. Japan Telegraph and Telephone Corporation (56) References JP-A-4-33432 (JP, A) Actual development Sho 62-80445 (JP, U) (58) Field (Int.Cl. ^7, DB name) H04L 12/28 - 12/44

Claims (6)

(57) [Claims] 1. A communication system in which a plurality of terminal devices and one subscriber line terminating device share one transmission line by polling in a time division manner to perform transmission, wherein the terminal device holds polling wait information. A polling waiting buffer, a polling request generating unit that detects the buffer length of the polling waiting buffer, compares the buffer length with a predetermined threshold value, and generates a polling request according to the comparison result, and the polling waiting buffer. And a multiplexer for multiplexing the output of the polling request generating means and sending it to a transmission line, wherein the subscriber line terminating device polls from a terminal device sent via the transmission line. A polling request identification unit that identifies a request, a minimum guaranteed polling generation unit that generates a minimum guaranteed poll, and a minimum guaranteed polling unit. A shared bandwidth control unit that receives the output of the polling generation unit and the output of the polling request identification unit and allocates a time slot to the free space of the minimum guaranteed polling according to the amount of polling waiting information. Dynamic time slot allocation system. 2. The polling request generation means compares the amount of information waiting in the polling waiting buffer with a predetermined threshold value, and polls the information about whether the waiting information amount is larger or smaller than the predetermined threshold value. 2. The dynamic time slot allocation system according to claim 1, wherein the subscriber line terminating device is notified to the subscriber line terminating device via the multiplexing unit, and the subscriber line terminating device changes the polling pattern according to the received polling information. 3. The polling request generation means compares the amount of information waiting in the polling waiting buffer with a plurality of thresholds, and which threshold exceeds the amount of information waiting. 2. The dynamic system according to claim 1, wherein the subscriber line terminating device is notified to the subscriber line terminating device via a multiplexer as a polling request, and the subscriber line device changes the polling pattern according to the received polling information. Time slot allocation system. 4. The dynamic time slot allocation system according to claim 1, wherein a polling request is inserted for each piece of information sent from the terminal device and transferred to the subscriber line terminating device. . 5. The polling request is inserted for each supervisory control information periodically sent from the terminal device and transferred to the subscriber line terminating device. Dynamic time slot allocation system. 6. The polling waiting buffer is provided for each service class, and the polling request generating means, if information remains in the polling waiting buffer of a service class having a high priority, the polling request generating means obtains information from the buffer having a high priority. In the case of a service class with a low priority, sending priority control is performed, and a polling request is generated by the polling request generating means by sharing the bandwidth, and time slots are allocated according to the amount of information in the polling waiting buffer. The dynamic time slot allocation system according to claim 1, characterized in that: