JP3977413B2 - Communication device - Google Patents

Description

  The present invention relates to a communication device. The present invention particularly relates to a time division multiple access (TDMA) control system in which a plurality of subscriber termination devices send out ATM cells in accordance with the access right issued by the station termination device in a point-multipoint transmission system. When a burst signal transmitted from a subscriber terminal connected to each subscriber termination device is generated, the station side termination device dynamically changes the bandwidth allocation between the subscriber termination devices according to the upstream traffic situation. Point / multipoint transmission system in which communication can be efficiently performed and the station-side terminating device provides multiple quality service types such as fixed band service and best effort service to subscriber terminals The present invention relates to a communication device suitable for use in

  As a conventional technique of the TDMA control method for performing band sharing, for example, a technique described in Japanese Patent Application Laid-Open No. 11-341037 is known. In this technology, a station-end device and a plurality of opposing subscriber-end devices are connected via a branch circuit, and each terminal device transmits a cell by time division multiple access control of the station-end device・ It is a multipoint transmission system.

This dynamic band sharing method has the following main features.
(1) Each subscriber terminal device transmits a cell accumulation amount and a transmission permission signal in a transmission cell buffer of each subscriber terminal device.

(2) The station-side terminal device periodically monitors the transmission cell buffer accumulation amount and the transmission permission signal of each subscriber terminal device.

(3) In the station-side terminal device, the transmission capacity allocated to the subscriber terminal device that requires more transmission capacity based on the transmission cell buffer storage amount and the transmission permission signal notified from each subscriber terminal device. In addition, the unused transmission area in the transmission frame is distributed according to the transmission cell buffer accumulation amount.

  In the prior art, the transmission capacity can be efficiently used for communication types with high burst characteristics such as personal computer communication by the above-described dynamic band sharing control method.

  The above-described conventional TDMA control system (bandwidth control system) has the following problems to be solved.

(1) Distribution logic 1: Necessity of minimum bandwidth In the prior art, the distribution ratio is determined only by the cell buffer state of the subscriber termination device. This is a technology in which, for example, a large amount of bandwidth is allocated to subscriber termination devices with extremely high transmission requests, and no bandwidth is guaranteed depending on the usage status of other subscriber termination devices. When considering actual service operation, each subscriber terminal device does not always provide only best effort services such as personal computer data communication. Multiple subscriber terminals are connected to the subscriber terminal equipment, for example, fixed-band services such as dedicated lines, comparatively high priority best effort services that transmit high-quality voice and images in real time, comparison of personal computer data communications, etc. When a plurality of quality service types are provided at the same time, such as a best effort service with low priority, it is necessary to guarantee a minimum bandwidth for a fixed bandwidth service for each subscriber terminal device. In addition, among the best effort services, there is a so-called minimum bandwidth guaranteed best effort service that needs to guarantee a minimum bandwidth. The minimum bandwidth for this needs to be guaranteed as well.

(2) Distribution logic 2: Necessity of maximum bandwidth and fair distribution logic Furthermore, the prior art system determines the distribution ratio only in the cell buffer state, and does not consider the contract of the subscriber termination device. There is no method. When providing the best effort service, it is necessary to determine the usage fee when contracting with the user, but in the case of a technology that can freely use the available free bandwidth as in the conventional technology, differentiation is made between users. Therefore, it is difficult to control the usage fee at a low cost, contrary to the efficiency of the bandwidth. Accordingly, there is a need for an ATM communication apparatus and a bandwidth control method thereof that can register a maximum usable bandwidth that can be used as a traffic parameter and that has a fair bandwidth distribution logic by weighting in consideration of a contract amount with a user. .

(3) Shared band: The maximum shared band distributed in the prior art is the entire transmission area in the transmission frame. When providing the best effort service of different quality for each subscriber terminal device, even if there is a difference between the best effort service qualities, it becomes impossible to differentiate and distribute each quality. Accordingly, there is a need for an ATM communication apparatus and a band control method therefor that include a shared band distribution logic capable of sharing a band between specific subscriber termination devices.

(4) Simplicity at the time of technology introduction: The above-described conventional technology is premised on that each subscriber termination device has a function of transmitting a cell accumulation amount of a transmission cell buffer and a transmission permission signal of each subscriber termination device. It has become. If this prior art is to be applied to a system that is already operating an actual service, not only is the station-side terminal device existing in the station updated, but the number of units is larger than that of the station-side terminal device because there are n branches. In addition, it is also necessary to update the subscriber termination device that may be set in the user's home or building. Therefore, there is a need for an ATM communication device and a bandwidth control method thereof that can realize bandwidth sharing by updating only the station-side terminal device. An object of the present invention is to provide a bandwidth control that secures a minimum bandwidth for each subscriber terminal and limits an upper limit bandwidth in order to solve the above-described problems, and shares a shared bandwidth fairly based on registration information. Providing a communication device that is distributed dynamically and fairly to each other, has a distribution logic for sharing bandwidth among specific subscriber termination devices, and can be easily adapted to a system that is already operating an actual service. It is in.

According to the solution of the present invention,
Connected to a plurality of subscriber termination devices via a branch circuit, granting data transmission permission to each of the subscriber termination devices, and receiving data from each of the subscriber termination devices using a communication band corresponding to the transmission permission A communication device for
A bandwidth monitoring unit for monitoring data received from each of the subscriber termination devices, and monitoring a communication bandwidth actually used by each of the subscriber termination devices;
Whether or not it is necessary to allocate a shared band, which is a communication band shared by the plurality of subscriber termination devices, using the actually used communication band monitored by the band monitoring unit. The subscriber who decides for each subscriber termination device, decides how much of the shared bandwidth is allocated to the subscriber termination device for which allocation of the shared bandwidth is necessary, and decides the allocation of the shared bandwidth For a terminal device for which a basic band that is guaranteed to be allocated is set in advance, the next band is permitted to be used by adding the shared band for which the allocation has been determined and the set basic band. The communication apparatus includes a bandwidth management unit that determines a communication bandwidth.

Moreover, according to the present invention,
The bandwidth management unit compares each of the plurality of subscriber termination devices by comparing the communication band to which transmission permission has been given before and the communication band actually used monitored by the bandwidth monitoring unit. It can be determined whether or not the shared band needs to be allocated.
Moreover, according to the present invention,
The bandwidth management unit, for any of the subscriber termination devices that have determined the shared bandwidth allocation,
Calculate how much of the shared bandwidth is allocated,
Comparing the calculated shared band with an upper limit band that is an upper limit value of the size of the shared band allocated to the arbitrary subscriber termination device,
When the calculated shared bandwidth is smaller than the upper limit bandwidth, the size of the determined shared bandwidth is
If it is large, the upper limit bandwidth is
It can be determined as a shared band to be distributed to the arbitrary subscriber termination device.

  According to the present invention, a station-side terminal device and a plurality of opposing subscriber terminal devices are connected via a branch circuit, and the plurality of the plurality of terminal terminal devices are set according to an upstream transmission band set by each of the subscriber terminal devices determined by a monitoring control unit. A station-side terminal device that issues an access right instruction to the subscriber terminal device, a plurality of subscriber terminal devices that send out ATM cells according to the access right issued by the station-side terminal device, and a plurality of subscriber terminal devices, respectively A plurality of subscriber terminals to be connected; and a monitoring control unit that registers each transmission band of the plurality of subscriber termination devices in the station-side termination device. An access line interface unit for receiving ATM cells transmitted from the terminating device and multiplexed by the branch circuit, and a network interface for transmitting the received ATM cells to the network. A transmission signal termination unit that receives ATM cells transmitted from the plurality of subscriber termination devices, and each of the subscriber termination devices set by the monitoring control unit. A TDMA control unit adapted to a point / multipoint transmission system including a TDMA control unit that issues an access right according to a transmission band, wherein the TDMA control unit includes traffic of uplink ATM cells transmitted from the plurality of subscriber termination devices. A traffic monitoring unit that monitors a state; a base band set by a monitoring control unit based on reception band information of a valid ATM cell and a cell overflow state transmitted by a plurality of subscriber termination devices detected by the traffic monitoring unit; A bandwidth management unit for determining an access bandwidth of each subscriber termination device according to an upper limit bandwidth; An access right management table that holds the access bandwidth determined by the bandwidth management unit, an access right generation unit that generates an access right according to the access bandwidth determined by the bandwidth management unit, and a bandwidth management unit according to a predetermined monitoring cycle. A monitoring period timing generation unit for generating a timing for performing a band determination process, wherein the traffic monitoring unit detects a reception band of a valid ATM cell transmitted by the subscriber termination device; and the subscriber termination A cell overflow state monitoring unit for detecting a cell overflow state of a transmission buffer in the apparatus, wherein the band management unit allocates a basic band set by the monitoring control unit, and a basic band set by the monitoring control unit Basic bandwidth memory that holds the bandwidth and upper bandwidth memo that holds the upper bandwidth set by the supervisory control unit And a shared band allocating unit for allocating a shared band based on the upper limit band set by the monitoring control unit, the reception band sent by the traffic monitoring unit and the cell overflow state, and a shared band memory for holding the allocated shared band. Provided TDMA control system (ATM communication apparatus and its bandwidth control method).

  Further, according to the present invention, in the shared band allocation unit, a bandwidth fair distribution unit that allocates a shared band based on a reception band and a cell overflow state transmitted by the traffic monitoring unit, and an upper limit band set by the monitoring control unit. An upper limit band limiting unit for limiting the upper limit band based on the above is provided. Furthermore, the present invention includes a plurality of sub-shared band memory units further divided in the shared band memory, and the shared band allocating unit selects any one of the sub-multiple shared band memory units for each subscriber terminal. A shared band selection unit for selecting.

  Also, as the cell overflow state detection means of the cell overflow state monitoring unit, the effective cell reception band received from each subscriber termination device is compared, and the access band determined by the bandwidth management unit and the received cell band of each subscriber termination device Cell overflow detecting means for determining that the cell overflows when the two are the same or similar. Alternatively, as the cell overflow state detection means of the cell overflow state monitoring unit, the cell overflow detection unit includes invalid cell detection means each received from the subscriber terminal device, and determines that the cell overflow state is detected when no invalid cell is detected. Means may be provided.

  Further, according to the present invention, the station-side terminal device and a plurality of opposing subscriber terminal devices are connected via a branch circuit, and according to the uplink transmission band set by each of the subscriber terminal devices determined by the monitoring control unit, A station-side terminal device that issues an access right instruction to a plurality of subscriber terminal devices, a plurality of subscriber terminal devices that send out ATM cells according to the access right issued by the station-side terminal device, and the plurality of subscriber terminal devices A plurality of subscriber terminals connected to each other, and a monitoring control unit for registering the transmission bands of each of the plurality of subscriber termination devices in the station-side termination device. An access line interface for receiving ATM cells transmitted from a subscriber terminal device and multiplexed by a branch circuit, and a network interface for transmitting the received ATM cells to the network. The access line interface receives ATM cells sent from the plurality of subscriber termination devices, and each of the subscriber termination devices set by the monitoring control unit grants an access right according to a transmission band. In a TDMA control system adapted to a point / multipoint transmission system that performs TDMA control to be issued, the traffic state of uplink ATM cells transmitted from the plurality of subscriber termination devices is monitored, and the plurality of subscriber termination devices transmit The reception bandwidth information and the cell overflow state of the effective ATM cell are detected, and the access bandwidth of each subscriber termination device is determined according to the effective ATM cell reception bandwidth information and the cell overflow state and the basic bandwidth and the upper limit bandwidth set by the monitoring controller. A bandwidth management means for determining is provided, and the bandwidth management operation timing is determined in advance. The bandwidth management unit performs bandwidth determination processing according to the monitored cycle, and as the bandwidth determination logic, secures the basic bandwidth defined for each subscriber terminal set by the monitoring control unit and sets it from the monitoring control unit. The shared band is distributed within the range of the specified upper limit band, and as the shared band distribution logic, the necessity for band distribution is determined for each subscriber terminal device, and weighting is performed according to the upper limit band set by the monitoring control unit. Based on the reception band and the cell overflow status sent by the traffic monitoring unit, the subscriber termination device in the cell overflow state or the supervisory control is used as the decision logic of the bandwidth distribution necessity for each subscriber termination device. ATM communication apparatus including logic for determining that band distribution is necessary for a subscriber terminal device in which a shared band is set beyond a basic band set by a unit, and its band control Provide a method.

In the present invention, the traffic monitoring unit monitors the reception band and the cell overflow state of each ATM cell transmitted by the subscriber terminal device. Therefore, when the present invention is applied to a system that is already operating an actual service, It is possible to apply the present invention without updating only the station-side terminal device existing in the station building and not updating the subscriber terminal device. In addition, it is possible to secure the minimum bandwidth of each subscriber termination device by allocating the access bandwidth to each subscriber termination device according to the basic bandwidth set by the monitoring control unit, and the upper limit bandwidth set by the monitoring control unit. Accordingly, it is possible to limit the access band of each subscriber termination device by limiting the access bandwidth to each subscriber termination device. In the bandwidth management unit, the shared bandwidth can be dynamically allocated to each subscriber termination device by distributing the shared bandwidth based on the reception bandwidth of the ATM cell and the cell overflow state at regular intervals.

Furthermore, the shared bandwidth is allocated fairly based on the registration information by allocating the shared bandwidth according to the ATM cell reception bandwidth, the cell overflow state, and the basic bandwidth and upper limit bandwidth set by the monitoring controller in the bandwidth fair distribution portion. It becomes possible to do. By dividing the shared band memory and selecting a sub-shared band for each subscriber terminal device, the sub-shared band is made to correspond to the quality of service (QoS), and between the subscriber terminal devices having the same QoS. Can share the bandwidth. In addition, by selecting a plurality of sub-shared bands for each subscriber termination device, when a plurality of QoS is accommodated in one subscriber termination device, the corresponding sub-shared band accommodates the corresponding QoS. It becomes possible to share the band between the subscriber terminal devices.

  According to the present invention, the reception band and the cell overflow information are monitored for each subscriber terminal, the basic band registered by the monitoring control unit is secured, and the shared band is set at a ratio according to the upper limit band registered by the monitoring control unit. By providing a means to distribute and suppress by the upper limit band, it is possible to control the band to secure the minimum band and limit the upper limit band, distribute the shared band fairly and dynamically based on the registration information, It is possible to provide an ATM communication apparatus and its bandwidth control method that can be easily adapted to a system that is already operating an actual service.

Embodiments of the present invention will be described below in detail with reference to the drawings. First, a related technique of the present invention will be described.
FIG. 8 is a block diagram showing the configuration of the point / multipoint transmission system. Hereinafter, the TDMA band control method will be described with reference to FIG. In the figure, this system includes a station-side terminal device 1, a supervisory control unit 2, subscriber-side terminal devices 3-1 to 3-n, subscriber terminals 4-1-1 to 4-nk, and a branch circuit 5. Prepare. Also, fixed band registration information 520 that the monitoring control unit 2 registers in the access line interface 10, transmission buffer information 540 that the subscriber-side terminal devices 3-1 to 3 -n send to the station-side terminal device 1, and an access right 560 Indicated.
In the point-multipoint transmission system, the station-side terminal device 1 and a plurality of opposing subscriber terminal devices 3-1 to 3-n are connected via a branch circuit 5. The station-side terminal device 1 includes an access line interface 10 and a network interface 13. The access line interface 10 includes a transmission signal termination unit 11 and a TDM control unit 550. Further, the TDM control unit 550 includes an access right generation unit 120, a transmission request monitoring unit 500, and a bandwidth management unit 510. The subscriber side termination devices 3-1 to 3-n include cell transmission buffers 30-1 to 30-n and TDMA control units 530-1 to 530-n.
In the station-side terminal device 1, the access right generation unit 120 issues an access right 560 to each subscriber terminal in accordance with the fixed band registration information 520 registered by the monitoring control unit 2 in the access line interface 10. The subscriber-side terminal devices 3-1 to 3 -n send an upstream signal according to the access right 560. Further, the subscriber-side terminators 3-1 to 3-n notify the station-side terminator 1 of the buffer accumulation amount of the transmission buffer 30 as transmission buffer information 540. The transmission request monitoring unit 500 periodically monitors the transmission buffer information 540, totals the transmission buffer information 540 sent from each of the subscriber side termination devices 3-1 to n, assigns a shared band, and assigns the allocation result to the access right. The generation unit 120 is notified.
FIG. 1 is a block diagram showing a system configuration according to the first embodiment of the present invention.
This system includes a station-side terminal device 1, a monitoring control unit 2, subscriber-side terminal devices 3-1 to 3 -n, subscriber terminals 4-1-1 to 4 -n-k, and a branch circuit 5. The station-side termination device 1 includes an access line interface 10, a network interface 13, a transmission signal termination unit 11, and a TDMA control unit 12. Further, the TDMA control unit 12 includes an access right generation unit 120, an access right management table 130, a monitoring cycle timing generation unit 170, a basic band allocation unit 1160, a basic band memory 1170, a shared band memory 1150, and an upper limit band memory 1180. Further, the basic band / upper limit band registration information 21 registered in the access line interface 10 by the monitoring control unit 2, the uplink cells 140-1 to 140-n transmitted from the respective subscriber termination devices, and the respective subscriber terminations transmitted from the traffic monitoring unit. The uplink cell reception bands 161-1 to n sent from the device, the cell overflow states 162-1 to 16-n of the respective subscriber termination devices 3 sent by the traffic monitoring unit, and the monitoring cycle timing 171 generated by the monitoring cycle timing generation unit Indicated. The traffic monitoring unit 100 includes reception band monitoring units 110-1 to 110-n that monitor uplink cell reception bands transmitted from subscriber termination devices, and a cell overflow state monitoring unit 120 that monitors cell overflow states of each subscriber termination device. -1 to n. In addition, the bandwidth management unit 1100 includes an upper limit bandwidth limiter 1110 and a bandwidth fair distribution unit 1120. Subscriber side termination devices 3-1 to -n include cell transmission buffers 30-1 to 30-n.

  In this embodiment, the traffic monitoring unit 100 monitors the traffic state of the uplink ATM cells 140-1 to 140-n transmitted from a plurality of subscriber termination devices. The bandwidth management unit 1100 further performs monitoring based on the reception bandwidth information 161-1 to 16-n of the valid ATM cells and the cell overflow states 162-1 to 16-n transmitted by the plurality of subscriber termination devices detected by the traffic monitoring unit 100. The access band of each subscriber terminating device is determined according to the basic band / upper limit band 21 set by the control unit 2. The access right management table 130 holds the access bandwidth determined by the bandwidth management unit 1100. The access right generation unit 120 generates an access right according to the access band determined by the band management unit 1100. The monitoring cycle timing generation unit 170 generates a monitoring cycle timing 171 for performing the bandwidth determination process of the bandwidth management unit 1100 according to a predetermined monitoring cycle. The traffic monitoring unit 100 includes a reception band monitoring unit 110 that detects the reception band 161 of the valid ATM cell 140 transmitted by the subscriber termination device 3, and a cell overflow state 162 of the transmission buffer 30 in the subscriber termination device 3. A cell overflow state monitoring unit 120 for detection is provided.

  The band management unit 1100 includes a basic band allocation unit 1160 that allocates a basic band set by the monitoring control unit 2, a basic band memory 1170 that holds the basic band set by the monitoring control unit 2, and the monitoring control unit 2. An upper-limit bandwidth memory 1180 that holds the set upper-limit bandwidth, and a shared bandwidth allocation that allocates a shared bandwidth based on the upper-limit bandwidth set by the monitoring control unit 2, the reception bandwidth 161 sent by the traffic monitoring unit 100, and the cell overflow state 162 Unit 1101 and a shared band memory 1150 that holds the allocated shared band. Further, the shared band allocation unit 1101 is based on the band fair distribution unit 1120 that allocates the shared band based on the reception band and the cell overflow state transmitted by the traffic monitoring unit 100, and the upper limit band set by the monitoring control unit. An upper limit bandwidth limiter 1110 that limits the upper limit bandwidth is provided.

  The traffic monitoring unit 100 detects the reception bands 161-1 to 16-n and the cell overflow states 162-1 to 16-n from the uplink cells transmitted from the subscriber termination devices 3-1 to n, and transmits them to the band management unit 1100. To do. The shared bandwidth allocation unit 1101 of the bandwidth management unit 1100 detects the reception bandwidth 161 and the cell overflow state 162 at the monitoring cycle timing 171 generated by the monitoring cycle timing generation unit 170, and sends them to the subscriber termination devices 3-1 to n, respectively. Determine the shared bandwidth to be allocated. The shared band determined by the shared band allocation unit 1101 of the shared band management unit 1100 is added to the basic band transmitted by the basic band allocation unit 1160 and is registered in the access right management table 130 as the access band 150. The access right generation unit 120 issues an access right to the subscriber termination device 3 according to the access bandwidth for each subscriber termination device 3 registered in the access right management table 130.

  FIG. 2 shows a first embodiment of cell overflow monitoring means in the cell overflow status monitoring units 120-1 to 120-n. Here, the cell overflow monitoring unit 120-n represents a band comparison type cell overflow detection method in which the set access right is compared with the reception band to determine cell overflow. The band comparison unit 121 compares the reception effective cell band 161-n input from the monitoring reception band monitoring unit 110-n with the access band to the subscriber terminal device n already set in the access right management table 130, When both are the same or approximate, it is determined that the cell overflows. Note that the band comparison unit 121 may perform another appropriate comparison process to determine the cell overflow state.

  FIG. 3 shows a second embodiment of the cell overflow monitoring means in the cell overflow state monitoring unit 120. Here, the cell overflow monitoring unit 120-n represents an invalid cell detection type cell overflow detection method for determining a cell overflow state by detecting an invalid cell. The invalid cell detection unit 122 determines that the cell overflows when no invalid cell is detected from the reception cell 140.

  Next, a second embodiment of the bandwidth management unit 1100 will be described. FIG. 4 shows a block diagram of a multi-divided type band sharing system including a shared band memory divided into a plurality of shared bands. The shared band memory 1150 includes a plurality of sub shared band memories 1151-1 to 1151-1m, and further includes a sub shared band selection unit 1140. In the figure, the secondary shared band selection signal 1130 is the secondary shared band area registration signal 23. The shared band allocation unit 1101 selects any one of the plurality of sub shared band memories 1151-1 to 1151-m by the sub shared band selection signal 1130. The fair bandwidth distribution unit 1120 allocates a sub-shared band to be allocated to the corresponding subscriber termination device 3 from the sub-shared band memories 1151-1 to 1151-1m selected by the sub-shared band selection signal 1130. The supervisory control unit 2 registers the area allocation designation of each sub-shared band and the subscriber termination devices belonging to each sub-shared band. In the shared band allocation unit 1101, the band fair distribution unit 1120 allocates the shared band to each of the subscriber termination devices 3-1 to 3-n and limits the upper limit band.

Details of the bandwidth allocation method of the bandwidth management unit 1100 including the shared bandwidth allocation unit 1101 and the basic bandwidth allocation unit 1160 will be described below. FIG. 5 is an explanatory view showing a transmission band dividing concept divided when an access band is allocated to each subscriber terminating device in the present invention. The band division method according to the present invention classifies the transmission band 600 into a basic band 630 (hereinafter referred to as BBW) and a shared band 610 (hereinafter referred to as SBW). The BBW 630 is a sum of all the subscriber termination devices 3-1 to n in the basic band 630-i (hereinafter referred to as BBW (i)) for each of the subscriber termination devices 3-i registered by the monitoring control unit 2. is there. On the other hand, the shared band 610 is an area other than the basic band BBW 630 in the transmission band 600. The shared band SBW 610 is divided into a plurality of sub-shared band areas 620-1 to 620-m (hereinafter referred to as SBW — 1 to m), and each of the sub-shared band areas SBW — 1 to m 620-1 to each belongs to a subscriber termination device. Shared bandwidth 640-m-i (hereinafter referred to as EBW_m (i)).
Moreover, the dynamic allocation band of each subscriber termination device can be allocated to a plurality of sub-shared bands. For example, when the subscriber terminal device i is allocated to two types of sub-shared bands SBW_p and SBW_q, the individual dynamic allocation bands of the subscriber terminal device i are EBW_p (i) and EBW_q (i), respectively. EBW_p (i) shares a band with other individual dynamic allocation bands in SBW_p. On the other hand, EBW_q (i) shares a band with other individual dynamic allocation bands in SBW_q. This allows the same QoS to share a band when a plurality of QoS (p, q in this example) are accommodated in the subscriber terminal device i.

6 and 7 show a flowchart of bandwidth allocation control of the bandwidth management unit 1100. FIG. The bandwidth allocation method of this embodiment is performed in two stages, which are referred to as primary distribution and secondary distribution, respectively. The flow shown in this figure is the division logic in the sub-shared band SBW_m, but will be described as SBW in the figure below. The symbols in the flow will be described. In the flow, the subscriber termination device 3 is described as ONT (Optical Network Terminal), and hereinafter, the subscriber termination device 3 is referred to as ONT. BW_R [ONT] is a reception band received from the corresponding ONT, δ1 [ONT] is an identification flag that sets a value of 1 for an ONT that requires primary distribution and a value of 0 for an ONT that does not require primary distribution. is there. W1 [ONT] represents a distribution weight for each ONT at the time of primary distribution. TBW [ONT] is an upper limit band for each ONT set by the monitoring control unit 2. Here, the upper limit band is an upper limit band that can be allocated from the shared band SBW, and the relationship between TBW [ONT] and the contracted maximum band PCR [ONT] that can be used by the corresponding ONT is as follows. Defined in Note that the maximum bandwidth PCR [ONT] with the contract may correspond to or correspond to the transmission bandwidth 600.
TBW [ONT] = PCR [ONT] −BBW [ONT]
EBW1 [ONT] is a shared allocated bandwidth of the corresponding ONT as a primary distribution result. δ2 [ONT] is an identification flag that sets a value of 1 for an ONT that requires secondary distribution and a value of 0 for an ONT that does not require secondary distribution. W2 [ONT] represents a distribution weight for each ONT at the time of secondary distribution. ΔEBW is a band that becomes an allocation resource when performing secondary allocation.

  The operation will be described below according to this flowchart. First, when the monitoring cycle timing 171 is generated (S000), all ONT reception bands (BW_R [ONT]) and cell overflow information are acquired in step S010. If there is a cell overflow or the shared allocated bandwidth EBW [ONT] assigned to the corresponding ONT in the previous cycle is not 0, it is determined that primary allocation is necessary and δ1 [ONT] = 1 is set. In other cases, it is determined that the primary distribution is unnecessary, and δ1 [ONT] = 0 is set. If there is no ONT that needs to receive the primary distribution in step S015, 0 is set to the shared allocated band EBW [ONT] for all ONTs in step S500. If there is an ONT that requires primary distribution, a distribution weight W1 for each ONT is calculated in step S020. The distribution weight W1 is distributed in proportion to the upper limit band TBW [ONT]. The distribution weight W1 calculation formula is, for example, as follows.

W1 [ONT] = TBW [ONT] × δ1 [ONT] / Σ (TBW [ONT] × δ1 [ONT]) (Formula 1)
Σ in the above equation 1 is the sum for all ONTs. The shared bandwidth allocation to each ONT of the primary distribution by W1 is as follows.

EBW1 [ONT] = W1 [ONT] × SBW (Formula 2)

Here, the allocated bandwidth is confirmed in step S030. First, a determination is made according to the cell overflow state, and if there is a cell overflow, the process branches to step S510, and if there is no cell overflow, the process branches to step S520.
In step S510, it is determined whether the shared allocation band EBW1 [ONT] as the primary distribution result exceeds the upper limit band TBW [ONT]. When EBW1 [ONT] exceeds TBW [ONT], secondary allocation is impossible, and the secondary allocation flag δ2 [ONT] is set to 0, and the excessively allocated surplus bandwidth is subjected to secondary allocation. .DELTA.EBW [ONT], which is the allocation resource at the time, and EBW1 [ONT] as the upper limit value TBW [ONT]. On the other hand, if EBW1 [ONT] does not exceed TBW [ONT], the secondary distribution flag δ2 [ONT] is set to 1 in step S830, assuming that the corresponding ONT requires secondary distribution.

  On the other hand, in S520, the primary distribution result EBW1 [ONT] + basic band BBW [ONT] is compared with the reception band BW_R [ONT], and the primary distribution result EBW1 [ONT] + basic band BBW [ONT] is received band BW_R. If [ONT] is exceeded, it is considered that secondary allocation is unnecessary, the secondary allocation flag δ2 [ONT] is set to 0, and the allocated resources for performing secondary allocation of the excessively allocated surplus bandwidth ΔEBW [ONT], and EBW1 [ONT] is defined as reception band BW_R [ONT] −basic band BBW [ONT]. On the other hand, if the primary distribution result EBW1 [ONT] + basic band BBW [ONT] does not exceed the reception band BW_R [ONT], it is considered that secondary distribution is necessary for the corresponding ONT in S870. The flag δ2 [ONT] is set to 1.

  Based on the secondary distribution flag δ2 [ONT] determined in the above process, if there is no ONT that receives the secondary distribution in step S040, the final shared band EBW [ONT] is set to 1 in step S540. The next distribution result is EBW1 [ONT].

  Next, when there is an ONT that receives the secondary distribution, a distribution weight W2 for each ONT is calculated in step S050. The distribution weight W2 is distributed in proportion to the upper limit band TBW [ONT]. The distribution weight W2 calculation formula is, for example, as follows.

W2 [ONT] = TBW [ONT] × δ1 [ONT] × δ2 [ONT] / Σ (TBW [ONT] × δ1 [ONT] × δ2 [ONT]) (Formula 3)
Σ in Equation 3 is the sum for all ONTs. Shared bandwidth allocation to each ONT of secondary distribution by W2 is as follows.

EBW2 [ONT] = W2 [ONT] × ΔEBW (Formula 4)
Here, in step S060, the primary distribution result and the secondary distribution result are totaled to calculate the shared allocation band EBW [ONT] as the final result.

EBW [ONT] = EBW1 [ONT] + EBW2 [ONT] (Formula 5)
Finally, in S070, the upper limit of the shared band EBW [ONT] is checked with the upper limit band TBW [ONT], and the upper limit is suppressed. The distribution shared band EBW [ONT] for the ONT calculated in the above process is set as the output of the shared band allocation unit in S080.
The flowcharts shown in FIGS. 6 and 7 show the embodiment of band distribution within a specific sub-shared band. Next, an operation of assigning a plurality of sub-shared bands will be described.
FIG. 9 is a flowchart for assigning bands to the basic band and the sub-shared band in the band management unit 1100. In S1000, the basic bandwidth is preferentially allocated. Next, a shared band is allocated. In S1010 and after, an allocation priority is given between the sub-shared bands, and allocation is performed in order from the sub-shared band having the highest allocation priority. That is, according to the second priority (k = 1, 2, 3,...), The sub-shared bands are sequentially allocated (S1010 to S1012), and when the allocation is completed (S1013), the process is terminated. In this case, for example, an appropriate storage unit may be provided, the priorities may be stored in advance, and the bandwidth management unit 1100 may be configured to refer to this when allocating.
In the flowcharts shown in FIGS. 6 and 7, the embodiment is shown in which the distribution weight is distributed in proportion to the upper limit band TBW [ONT]. As another embodiment of the allocation method, in addition to making the bandwidth allocation proportional to the upper limit bandwidth TBW [ONT], it can also be made proportional to the basic bandwidth BBW [ONT]. It is also possible to distribute equally between multiple ONTs without assigning priority.
Further, in the above description, a method of constantly allocating a band for BBW [ONT] has been described. However, in another embodiment of BBW [ONT] allocation, it can be related to the reception band BW_R [ONT]. That is, in S010, when the reception band BW_R [ONT] is equal to or less than the basic band BBW [ONT], BW_R [ONT] is allocated without BBW [ONT], and the remaining band “BBW [ONT] −BW_R [ ONT] ”can be used as a shared band. In this way, the bandwidth can be effectively utilized by the primary distribution “SBW ′ = SBW + BBW [ONT] −BW_R [ONT]”.
The distribution method proportional to the upper limit band TBW [ONT] and the distribution method proportional to the basic band BBW [ONT] shown so far can be defined for each sub-shared band. In addition, as a basic band BBW [ONT], a method of constantly allocating a band in a fixed manner and a method of allocating it in relation to the reception band BW_R [ONT] are shown. On the other hand, in the present invention, a plurality of types of basic bands can be provided independently at the same time, and a band allocation method can be defined for each basic band. In this case, allocation priority is given to a plurality of basic bands, and allocation is performed from a basic band having a high allocation priority. When it is necessary to refer to the basic band in each sub-shared band, a specific basic band is referred to among the plurality of basic bands. In this case, for example, an appropriate storage unit may be provided, the priorities may be stored in advance, and the bandwidth management unit 1100 may be configured to refer to this when allocating.
In the flowcharts shown in FIG. 6, FIG. 7, and FIG. 9, an example of application to a system that allocates bandwidth for each subscriber termination device ONT has been shown. However, a plurality of subscriber contracts exist in one subscriber termination device ONT. However, the present invention can also be applied to a case where the band allocation unit is allocated independently for each subscriber contract, not for each subscriber termination device ONT. In this case, the access right is not issued for each subscriber termination device ONT, but is applied to a system issued for each subscriber contract, and can be applied without changing the above-described flowchart. In this case, a storage unit that stores in advance appropriate data required for assignment of attributes, identifiers, priorities, and the like for each of a plurality of subscriber contracts is provided for one subscriber terminal device ONT, and a bandwidth management unit 1100 May be configured to refer to this when allocating.

  The present invention is not limited to the TDMA system and can be applied to other appropriate multiplexing systems.

1 is a block diagram showing a system configuration according to a first embodiment of the present invention. The block diagram of 1st embodiment of the cell overflow monitoring means in cell overflow state monitoring part 120-1 to n. The block diagram of 2nd embodiment of the cell overflow monitoring means in the cell overflow state monitoring part 120. FIG. The block diagram about the multiple division | segmentation type | mold band sharing system provided with the shared band memory divided | segmented into the multiple shared band. Explanatory drawing which shows the transmission band division | segmentation concept divided | segmented when allocating an access band to each subscriber termination | terminus apparatus in this invention. The flowchart (1) of the bandwidth allocation control of the bandwidth management unit 1100. The flowchart (2) of the bandwidth allocation control of the bandwidth management unit 1100. The block diagram which shows the structure of a point multipoint transmission system. The flowchart which allocates a band to the basic band and sub-shared band in the band management part 1100.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Station side termination | terminus apparatus 10 Access line interface 100 Traffic monitoring part 11 Transmission signal termination | terminus part 110 Band management part 110-1 to n Reception band monitoring part 1110 which monitors an uplink cell receiving band Limitation band limiting part 1120 Band fair distribution part 1130 Shared Band selection signal 1140 Shared band selection unit 1150 Shared band memory 1151-1 to m Sub shared band memory 1160 Basic band allocation unit 1170 Basic band memory 1180 Upper limit band memory 12 TDMA control unit 120 Access right generation unit 120-1 to n Cell overflow Cell overflow state monitoring unit 121 that monitors the state Bandwidth comparison unit 122 Invalid cell detection unit 13 Network interface 130 Access right management table 140-1 to n Each uplink cell 161-1 to n transmitted from each subscriber termination device Sent from the terminating device Upstream cell reception band 162-1 to n Cell overflow state 170 of each subscriber termination device 3 Monitoring period timing generation unit 171 Monitoring period timing 2 generated by the monitoring period timing generation unit Monitoring control unit 21 Basic band / upper limit band registration information 23 Sub-shared band region registration signals 3-1 to 3-n Subscriber side termination devices 30-1 to 30-n Cell transmission buffers of subscriber side termination devices 4-1-1 to 4-nk Subscriber terminal 5 Branch circuit 500 Transmission request monitoring unit 510 Band management unit 520 Fixed band registration information 540 Transmission buffer information 550 TDM control unit 600 Transmission band 610 Shared band 620-1 to m Sub shared band region 630 Basic band 630-i For each of the subscriber termination devices Basic band 630-i
640-m-i Shared bandwidth allocated to subscriber termination equipment

Claims (3)

Connected to a plurality of subscriber termination devices via a branch circuit, granting data transmission permission to each of the subscriber termination devices, and receiving data from each of the subscriber termination devices using a communication band corresponding to the transmission permission A communication device for
A reception band monitoring unit for detecting a reception band of a valid cell transmitted by the subscriber termination device and a cell overflow state monitoring unit for detecting a cell overflow state, and monitoring data received from each of the subscriber termination devices A bandwidth monitoring unit for monitoring a communication bandwidth actually used by each of the subscriber termination devices;
Whether or not it is necessary to allocate a shared band, which is a communication band shared by the plurality of subscriber termination devices, using the actually used communication band monitored by the band monitoring unit. The subscriber who decides for each subscriber termination device, decides how much of the shared bandwidth is allocated to the subscriber termination device for which allocation of the shared bandwidth is necessary, and decides the allocation of the shared bandwidth For a terminal device for which a basic band that is guaranteed to be allocated is set in advance, the next band is permitted to be used by adding the shared band for which the allocation has been determined and the set basic band. a bandwidth management unit which determines as the communication band, and a shared bandwidth memory comprised of a plurality of sub-shared bandwidth memory has a shared band selection unit, any one of the plurality of sub-shared bandwidth memory Wherein selected by the shared band selection unit, it allocates the shared bandwidth to be allocated to the subscriber termination unit from the sub-shared bandwidth memory selected by the shared band selection unit, the bandwidth management section,
An access right management table that holds the access bandwidth determined by the bandwidth management unit , and

The bandwidth monitoring unit compares the reception effective cell bandwidth input from the monitored reception bandwidth monitoring unit with the access bandwidth to the subscriber termination device that is already set in the access right management table. Detect
The bandwidth management unit acquires a reception bandwidth and a cell overflow state from the bandwidth monitoring unit, and when there is a cell overflow or the shared allocated bandwidth assigned to the corresponding subscriber termination device in the previous cycle is not 0. Determines that a primary allocation is required,

The bandwidth management unit, for any of the subscriber termination devices that have determined the primary allocation of the shared bandwidth,
Calculating the sum of the upper limit bands of a plurality of terminal devices that primarily distribute the shared band;
Calculate the ratio of the upper limit band of any of the subscriber termination devices to the total of the upper limit band,
Calculating a part of the shared band according to the calculated ratio as a shared band that is primarily distributed to any of the subscriber termination devices;

If the bandwidth management unit determines that there is a cell overflow, for any of the subscriber termination devices that have determined the primary allocation of the shared bandwidth,
Comparing the calculated shared band with an upper limit band that is an upper limit value of the size of the shared band allocated to any of the subscriber termination devices,
When the calculated shared band is larger than the upper limit band, it is considered that secondary distribution is impossible, the upper limit band is determined as a shared band that is primarily distributed to any of the subscriber termination devices, and the calculation A difference obtained by subtracting the upper limit bandwidth from the shared bandwidth is calculated as a surplus bandwidth, and the surplus bandwidth is used as an allocation resource when performing secondary allocation,
When the calculated shared band is smaller than the upper limit band, the size of the determined shared band is determined as a shared band that is primarily distributed to any of the subscriber termination devices, and secondary distribution is required. Judgment
on the other hand,
When the bandwidth management unit determines that there is no cell overflow, for any of the subscriber termination devices that have determined the primary allocation of the shared bandwidth,
Compare the sum of the shared bandwidth and basic bandwidth of the primary allocation result with the received bandwidth,
When the sum of the shared band and the basic band of the primary distribution result exceeds the reception band, the secondary distribution is regarded as unnecessary, and a difference that is a value obtained by subtracting the basic band from the reception band is set as an arbitrary value for the subscriber termination. When determining a shared band to be primarily distributed to the apparatus, calculating a difference that is a value obtained by subtracting the reception band from the sum of the shared band and the basic band as a surplus band, and performing the secondary allocation of the surplus band As an allocated resource,
If the sum of the shared band and the basic band as a result of the primary allocation does not exceed the reception band, it is determined that secondary allocation is necessary for any of the subscriber termination devices;

The bandwidth management unit totalizes the secondary allocation determined based on the primary allocation and the surplus bandwidth to any of the subscriber termination devices, and allocates a shared bandwidth,
The communication device according to the communication device , wherein the bandwidth management unit confirms the upper limit of the calculated shared bandwidth and the upper limit bandwidth as a secondary distribution, and suppresses allocation of the shared bandwidth by the upper limit bandwidth . The communication device according to claim 1,
A timer for measuring a predetermined time and notifying the bandwidth management unit every time the predetermined time elapses;
When the notification from the timer is received, the bandwidth management unit newly determines a communication bandwidth to be allowed next for each of the subscriber termination devices. The communication device according to claim 1,
Communication between the communication terminal device and the subscriber terminal device follows the ATM protocol,
When the bandwidth management unit does not detect an invalid cell from the data received from any of the subscriber termination devices, the bandwidth management unit communicates larger than the communication band to which the arbitrary subscriber termination device previously granted transmission permission. A communication device characterized by determining that a bandwidth is required.

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