JP2017059972A - Optical line terminal and band control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform band allocation to a larger number of identification IDs without increasing a hardware scale.SOLUTION: An ID conversion section 14 converts identification IDs acquired from an Optical Network Unit 20 by a signal processing section 13 to allocation IDs to notify a band control section 15 of the allocation IDs; converts allocation IDs corresponding to uplink bands allocated by the band control section 15 to identification IDs to notify the signal processing section 13 of the identification IDs; in performing the conversion, classifies the identification IDs into a plurality of groups, the number of which is equal to or smaller than a set number that is set in advance; and, for each group, performs conversion so that identification IDs belonging to the group are associated with allocation IDs on a one-to-one basis. In allocating the uplink bands, the band control section 15 allocates, for each allocation period to each groups set in a band control period, an uplink band composed of time segments set by time-dividing the allocation period to allocation IDs corresponding to identification IDs belonging to the group.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a communication system such as a PON (Passive Optical Network) system, and in particular, an upstream band for transmitting an uplink signal from each subscriber-side communication device to a station-side communication device from each station-side communication device. The present invention relates to a bandwidth control technique that is allocated in a time division manner to a subscriber-side communication device.

  There is a PON system as an optical communication system including a communication device that transmits and receives optical signals and an optical fiber that connects these communication devices. FIG. 10 is a configuration example of a general PON system. The PON system includes a station side communication device (OLT: Optical Line Terminal) and a plurality of subscriber side communication devices (ONU: Optical Network Unit) connected via an optical splitter SP. When performing point-multipoint communication with a plurality of subscriber side communication devices, an economical system is realized by sharing the station side communication device and the optical fiber with the plurality of subscriber side communication devices.

  In such a PON system, uplink signals are transmitted by a time division multiplexing method so that uplink signals transmitted from a plurality of subscriber side communication devices to a station side communication device do not interfere. FIG. 11 is an example of uplink bandwidth allocation for the subscriber-side communication device. The subscriber side communication apparatus accommodates one or a plurality of users, and when each user links up, an ID for user identification is assigned from the station side communication apparatus. The station-side communication apparatus determines and notifies the uplink transmission period of each ID, and the subscriber-side communication apparatus transmits an uplink signal of each ID during the notified period.

  FIG. 12 is an explanatory diagram showing a general band control sequence. In the 10G-EPON system disclosed in Non-Patent Document 1, as shown in FIG. 12, first, the bandwidth request signal transmission period and the uplink of each ID are assigned as allocation periods from the station side communication apparatus to each subscriber side communication apparatus. The data transmission period is notified by a transmission permission signal. The subscriber-side communication device transmits the bandwidth request signal to the notified bandwidth request signal transmission period and the uplink data to the station-side communication device during the uplink data transmission period. Here, the band request signal is a signal storing the amount of uplink data stored in each ID in the subscriber side communication apparatus, and is transmitted to the station side communication apparatus to request the uplink band.

  The station side communication apparatus that has received the band request signal uses the uplink accumulated data amount and the like to determine the next band request signal transmission period and uplink data transmission period to be allocated, and notifies the subscriber side communication apparatus with a transmission permission signal. When the period for receiving the band request signal (band control period) is long, the delay of the uplink signal transmitted from the subscriber side communication apparatus becomes large. When the period is short, the band allocation process in the station side communication apparatus may not be completed within the period. is there. Therefore, generally optimum values, or minimum and maximum values are set as the band control period.

As an uplink band allocation method, for example, the transmission period of accumulated data notified by a band request signal is allocated in the order of ID, and the last ID is set so that the band control period is within a preset minimum value and below a maximum value. Is set (Patent Document 1).
In XG-PON, the station side communication device monitors the amount of uplink traffic of each ID transmitted from the subscriber side communication device, and assigns the uplink bandwidth to each ID in consideration of the traffic amount. For example, it is assumed that the uplink data transmission period allocated to the next bandwidth control cycle is proportional to the traffic volume in the previous bandwidth control cycle (Non-Patent Document 2).

  FIG. 13 is a configuration example of a station side communication apparatus that performs band control. This station-side communication apparatus includes a subscriber-side I / F unit, a host-side I / F unit, a signal processing unit, and a bandwidth control unit, and a plurality of subscriber-side units are connected to the subscriber-side I / F unit via optical fibers. The communication device and the host I / F unit transmit and receive signals to and from the host network. The subscriber-side I / F unit outputs the bandwidth request signal to the signal processing unit when the bandwidth request signal is input from the subscriber-side communication device, and the signal processing unit outputs the input bandwidth request signal to the bandwidth control unit.

  The bandwidth control unit acquires the requested amount of the upstream bandwidth from the input bandwidth request signal, performs allocation calculation, and outputs the allocation result to the signal processing unit. The signal processing unit creates a transmission permission signal for notifying the allocation result and transmits it to the subscriber side communication device via the subscriber side I / F unit. Band allocation is performed for each identification ID for user identification as described above, and the signal processing unit performs processing necessary as a system such as encoding in addition to the above processing.

Japanese Patent No. 3768422

IEEE 802.3 av ITUT G. 987.3

  For example, in the case of a 10G-EPON system, the bandwidth control unit is generally implemented by hardware that can be assigned to the number of identification IDs of 32 branches or less defined in the standard. Therefore, according to the prior art, if the number of branches is equal to or less than the set number assumed at the time of hardware design, processing can be performed at high speed, and the bandwidth control cycle can be shortened. However, the number of branches is generally determined in consideration of light attenuation. In the situation where the performance of the receiver is improved or the distance between the station side communication device and the subscriber side communication device is short, the number of branches is increased. Can do.

  For this reason, at the time of operation, bandwidth allocation may be required for the number of branches exceeding the number set at the time of hardware design, that is, the number of identification IDs. Considering this, if the hardware is designed so as to be able to cope with a larger number of identification IDs, there is a problem that the ID management register and the arithmetic circuit become large and the circuit scale increases. In addition, it is conceivable to perform bandwidth allocation processing by software instead of hardware, but it is practically difficult because the processing time increases significantly, so that the bandwidth update cycle becomes longer and the delay of the upstream signal increases. is there.

  The present invention is for solving such a problem, and an object of the present invention is to provide a bandwidth control technique capable of performing bandwidth allocation for more identification IDs without increasing the hardware scale. Yes.

  In order to achieve such an object, a station-side communication apparatus according to the present invention accommodates a plurality of subscriber-side communication apparatuses, and sets a bandwidth control period for each identification ID used in these subscriber-side communication apparatuses. A station-side communication device that allocates an uplink band for uplink signal transmission composed of divided time sections, and a bandwidth control unit that allocates the uplink band to a preset number of allocation IDs; A signal processing unit that acquires the identification ID notified from the subscriber-side communication device and notifies the subscriber-side communication device together with the identification ID of the uplink band allocated by the band control unit; The identification ID acquired by the unit is converted into the allocation ID and notified to the band control unit, and the allocation ID corresponding to the uplink band allocated by the band control unit is An ID conversion unit that converts the ID into another ID and notifies the signal processing unit, and the ID conversion unit classifies the identification ID into a plurality of groups with a number equal to or less than the set number in the conversion. For each group, the identification ID belonging to the group and the allocation ID are converted in a one-to-one correspondence, and when the bandwidth control unit allocates the upstream bandwidth, each of the bandwidth IDs set in the bandwidth control cycle For each group allocation period, the uplink bandwidth composed of a time interval set by time-sharing the allocation period is allocated to an allocation ID corresponding to an identification ID belonging to the group.

  Also, in one configuration example of the station side communication device according to the present invention, the ID conversion unit has an ID conversion table indicating a correspondence relationship between the identification ID and the allocation ID, and the identification ID and the allocation ID Are converted with reference to the ID conversion table.

  Also, one configuration example of the station side communication apparatus according to the present invention is such that the ID conversion table dynamically changes the correspondence according to an external input.

  Further, in the above configuration example of the station side communication device according to the present invention, when the ID conversion unit converts the identification ID into the allocation ID, the higher-order bits of the identification ID are deleted to delete the allocation ID. This is converted to an ID.

  Also, in one configuration example of the station side communication device according to the present invention, when the number of the identification IDs is smaller than the number of the allocation IDs, the ID conversion unit uses the identification ID as the allocation ID. It is intended to be used.

  Also, in one configuration example of the station-side communication device according to the present invention, the signal processing unit is configured to receive a bandwidth request amount included in a bandwidth request notified from the subscriber-side communication device, or the subscriber-side communication device. The bandwidth request amount obtained by measuring the amount of uplink traffic is output to the bandwidth control unit, and the bandwidth control unit performs the bandwidth allocation based on the bandwidth request amount from the signal processing unit. Is.

  In addition, the bandwidth control method according to the present invention includes a plurality of subscriber side communication devices, and includes a time interval in which the bandwidth control period is set by time division for each identification ID used in these subscriber side communication devices. A bandwidth control method used in a station-side communication device that allocates an upstream band for uplink signal transmission, the bandwidth control step of allocating the upstream band to a preset number of allocation IDs, and the subscriber A signal processing step of acquiring the identification ID notified from the communication device on the side and notifying the subscriber communication device together with the identification ID of the uplink band allocated in the bandwidth control step, and acquiring in the signal processing step The identified ID is converted into the allocation ID and notified to the bandwidth control step, and the uplink allocated in the bandwidth control step An ID conversion step of converting the allocation ID corresponding to the area into the identification ID and notifying the signal processing step, wherein the ID conversion step reduces the identification ID to the set number or less during the conversion. The number is classified into a plurality of groups, and for each of these groups, the identification ID belonging to the group and the allocation ID are associated with each other in a one-to-one correspondence, and the bandwidth control step is performed when allocating the uplink bandwidth, For each allocation period of each group set within the band control period, the uplink band consisting of a time interval set by time-sharing the allocation period is assigned to an allocation ID corresponding to an identification ID belonging to the group. Are assigned to each.

  According to the present invention, the number of identification IDs belonging to one group is equal to or less than the set number that can be processed by the bandwidth control hardware of the bandwidth control unit. Therefore, for each of these groups, the identification ID belonging to the group is converted into the allocation ID on a one-to-one basis, and the time interval set by time-sharing the allocation period of the group is the allocation ID, that is, the identification ID. Will be allocated as the upstream bandwidth.

  For this reason, in the conventional example, if the number of IDs in the bandwidth control unit is increased in accordance with the increase in the number of branches, the hardware scale increases. However, according to the present embodiment, the hardware design is performed without increasing the hardware scale. Uplink bandwidth can be assigned to a larger number of identification IDs than the set number of times. Therefore, even when the performance of the receiver is improved or the distance between the station side communication device and the subscriber side communication device is short, even if it is required to cope with the number of branches exceeding the set number at the time of hardware design, It becomes possible to respond flexibly. As a result, the cost and power consumption of the station side communication apparatus and the entire communication system can be reduced. In addition, network equipment can be shared by more subscriber side communication devices, which can contribute to cost reduction in the entire communication system.

It is a block diagram which shows the structure of the station side communication apparatus concerning 1st Embodiment. It is a structural example of an ID conversion table. It is an example of ID conversion. It is another ID conversion example. It is explanatory drawing which shows the group classification example. It is an example of ID assignment. It is a sequence diagram which shows the uplink band allocation operation | movement concerning 1st Embodiment. It is another example of ID assignment. It is a sequence diagram which shows the uplink band allocation operation | movement concerning 2nd Embodiment. It is a structural example of a general PON system. It is an example of uplink band allocation with respect to a subscriber side communication apparatus. It is explanatory drawing which shows a general band control sequence. It is an example of a structure of the station side communication apparatus which performs zone | band control.

Next, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
First, with reference to FIG. 1, the communication system 1 and the station side communication apparatus 10 concerning the 1st Embodiment of this invention are demonstrated. FIG. 1 is a block diagram illustrating a configuration of a station-side communication device according to the first embodiment.
This communication system 1 is composed of one station side communication device 10 and N (N is an integer of 2 or more) subscriber side communication devices 20, and these subscriptions are made via an optical splitter SP and an optical fiber L. The person side communication device 20 is accommodated in the station side communication device 10.

  The station side communication device 10 has a function of relaying and transferring data communication between a user terminal (not shown) connected to the subscriber side communication device 20 and a host device (not shown), and these subscribers. Each identification ID used in the side communication device 20 has a function of allocating a communication band set by time division for each predetermined band control period as an uplink band for uplink signal transmission.

  The subscriber-side communication device 20 is connected to one or a plurality of user terminals (not shown), and based on an identification ID for user identification given from the station-side communication device 10 to these user terminals (users). A function of performing optical communication with the station-side communication device 10, a function of notifying the station-side communication device 10 of a bandwidth request signal including an uplink bandwidth required by the user terminal and an identification ID of the user terminal, A function of transmitting an uplink signal from the user terminal to the station side communication device 10 based on a transmission permission signal notified from the station side communication device 10 and a relay signal received from the station side communication device 10 to the user terminal It has a function.

  As shown in FIG. 1, in this communication system 1, the optical fiber L is shared by each subscriber-side communication device 20 in the section between the station-side communication device 10 and the optical splitter SP. The uplink signal transmitted from 20 is time-division multiplexed by the optical splitter SP and then transferred to the station side communication device 10. For this reason, the upstream band is allocated from the station side communication device 10 to the subscriber side communication device 20 so that the uplink signal transmitted from the subscriber side communication device 20 does not interfere in the above-mentioned section.

  In the following, a specific communication system to which the present invention is applied consists of a PON (Passive Optical Network) system, and the OLT (OLT: Optical Line) in which the station side communication device 10 and the subscriber side communication device 20 are respectively used in the PON system. A case in which each ONU is accommodated in an OLT via an optical splitter SP and an optical fiber L will be described as an example, but the present invention is not limited to this. . For example, the present invention can also be applied to a communication system including a time division multiplexing section as a communication path, such as some wireless communication systems.

  As shown in FIG. 1, the station side communication apparatus 10 according to the present embodiment includes, as main circuit units, a subscriber side I / F unit 11, a higher level I / F unit 12, a signal processing unit 13, an ID. A conversion unit 14 and a band control unit 15 are provided.

  The subscriber side I / F unit 11 receives the optical signal transmitted from the subscriber side communication device 20 and the function of accommodating each subscriber side communication device 20 via the optical fiber L and the optical splitter SP. A function of photoelectrically converting and outputting the signal as an upstream signal to the signal processing unit 13 and a function of converting the downstream signal relayed and transferred from the signal processing unit 13 into an optical signal and transmitting the signal to each subscriber side communication device 20 using the optical signal. Have.

  The higher-level I / F unit 12 transmits a function of connecting to a higher-level device (not shown) such as a server via a gateway (not shown) and an upstream signal relayed and transferred from the signal processing unit 13 to the higher-level device. And a function of receiving a downlink signal transmitted from the host device and outputting it to the signal processing unit 13.

  The signal processing unit 13 joins the downlink signal output from the high-order I / F unit 12 and the function of relaying and transferring the uplink signal output from the subscriber-side I / F unit 11 to the high-order I / F unit 12. A function of relay transfer to the subscriber side I / F unit 11, a function of receiving a bandwidth request signal from the subscriber side communication device 20 via the subscriber side I / F unit 11, and outputting the bandwidth request signal to the ID conversion unit 14, and an ID It has a function of transmitting the transmission permission signal output from the conversion unit 14 from the subscriber side I / F unit 11 to the corresponding subscriber side communication device 20.

[ID converter]
The ID conversion unit 14 receives the bandwidth request signal output from the signal processing unit 13, converts the identification ID included in the bandwidth request signal into an allocation ID, and outputs the bandwidth ID to the bandwidth control unit 15. After receiving the transmission permission signal output from the control unit 15 and converting the allocation ID included in the transmission permission signal into the identification ID, the function to output to the signal processing unit 13 and the identification ID in advance at the time of conversion It has a function of classifying into a plurality of groups with a number equal to or less than the set number, and converting the identification IDs and assignment IDs belonging to the groups in a one-to-one correspondence with each other.

  In addition, the ID conversion unit 14 determines whether or not ID conversion is necessary for the identification ID included in the band request signal output from the signal processing unit 13. If ID conversion is necessary, the ID conversion unit 14 identifies the band request signal. After the ID is converted into the allocation ID, the ID is output to the band control unit 15. When the ID conversion is not necessary, the band request signal using the identification ID as the allocation ID is not performed to the band control unit 15 without performing the ID conversion. It has a function to output.

  The ID conversion unit 14 has an ID conversion table indicating a correspondence relationship between the identification ID and the allocation ID. When converting the identification ID and the allocation ID, the ID conversion unit 14 performs conversion with reference to the ID conversion table. FIG. 2 shows a configuration example of the ID conversion table. Here, for each identification ID, a group to which the identification ID belongs and an allocation ID are registered.

  In the configuration example of FIG. 2, the identification ID set when the signal processing unit 13 links up the communication link of the user terminal with the subscriber side communication device 20 is used for assigning # 0 to # 31 for each group. It is for converting to ID. As will be described later, the bandwidth control unit 15 is configured by dedicated hardware that performs bandwidth allocation equal to or less than a preset allocation ID number. In FIG. 2, allocation IDs # 0 to ## are used as allocation IDs. This is an example in which 32 pieces of 31 are prepared.

  The ID conversion unit 14 registers / deletes the identification ID corresponding to the communication link in the ID conversion table in response to link up / link down. When registering the identification ID, an allocation ID as a conversion destination is set. When band allocation is performed for each group, the group to which the identification ID belongs is also set.

  As an ID setting method for setting these groups and allocation IDs, the number of identification IDs to be classified into one group is set as a threshold, and when the number of identification IDs that are linked up is smaller than the threshold, the identification ID is assigned to the group There is a method in which the allocation ID is set to the same value as the identification ID by classifying it into 0, and when the identification ID number linked up is equal to or greater than the threshold, the identification ID is classified into group 1 and the allocation ID is allocated in order from 0. . The threshold value is set in the range of 1 to the number of allocation IDs.

  In the example of FIG. 2, the threshold is 32, the identification IDs # 0 to # 31 are classified into the group 0, and the allocation IDs # 0 to # 31 having the same number as the identification ID are respectively assigned. Further, the identification IDs # 32 to # 63 are classified into the group 1, and the allocation IDs # 0 to # 31 are assigned in order from the smallest identification ID number.

  In addition, after deleting the linked-down identification ID from the ID conversion table, for example, when the total number of identification IDs of two groups (group 0 and group 1) is less than or equal to the threshold, the two groups are grouped into one group (group 0). ). As a result, the number of groups can be automatically reduced, and overhead processing required for group switching can be reduced.

  Instead of using the ID conversion table, conversion to the allocation ID may be performed by deleting the upper bits in the binary display of the identification ID. For example, when the identification ID is # 0 to # 31 smaller than the threshold = 32, it is classified into the group 0 and the allocation ID is the same as the identification ID, and when the identification ID is # 32 to # 63 with the threshold = 32 or more, it is the group 1 is converted into an allocation ID having a number obtained by subtracting threshold = 32 from the identification ID number. Similarly, the identification IDs # 64 and after may be converted into allocation IDs # 0 to # 31.

  That is, when the threshold is expressed by a factorial of 2, the ID conversion process in the ID conversion unit 14 can be realized by an extremely simple bit operation of deleting / adding the most significant bit. For example, when the threshold value is 32 = 100000: binary, the assignment IDs # 0 to # 31 are binary numbers 000000 to 01111: bins, and the identification IDs # 32 to # 63 are 100000 to 111111: binary numbers. In this example, if the most significant bit “1” of the identification ID is deleted, it can be converted into an allocation ID, and if the most significant bit “1” is assigned to the allocation ID, it can be converted into an identification ID. The same applies to identification ID # 64 and subsequent.

FIG. 3 is an example of ID conversion, and shows an example corresponding to the ID allocation example of FIG. 6 described later. In this example, as in FIG. 2, 64 IDs are used as identification IDs of the subscriber side communication device 20, and identification IDs # 0 to # 31 are classified into group 0 based on threshold = 32. Identification IDs # 32 to # 63 are classified into group 1.
In the example of FIG. 3A, identification IDs # 0 to # 31 belonging to group 0 are not converted, and only IDs # 32 to # 63 belonging to group 1 are ID-converted. Therefore, the number of conversions is minimized, and there are effects of saving power and increasing speed.

  On the other hand, when giving priority in band allocation for each identification ID, the order may be changed within the group as shown in FIG. In the case where band allocation is preferentially performed as the allocation ID is smaller, in order to give priority to the identification ID # 31 in the group 0, the allocation ID # 0 allocated with the highest priority is assigned to the identification ID # 31. Allocation and the remaining IDs for allocation may be allocated in order from the smallest to the smallest identification ID.

  Also, in FIG. 3B, in group 1, assignment IDs # 1 and # 0 are assigned so that identification IDs # 61 and # 63 are given priority, and identification ID # 32 is given no priority. The largest assignment ID # 31 is assigned. According to this ID conversion method, the number of conversions is larger than that in FIG. 3A, but there is an effect that an upstream band can be allocated according to the priority of the identification ID.

  FIG. 4 shows another example of ID conversion, and shows an example corresponding to the ID allocation example of FIG. In this example, as in FIG. 2, 64 IDs are used as identification IDs of the subscriber side communication device 20, and the threshold value = 32. Among these, identification IDs # 0 to # 9 and # 42 to # 63 are classified into group 0, identification IDs # 10 to # 41 are classified into group 1, and group 0 has priority over group 1. Thus, it is assumed that the bandwidth is allocated.

  At this time, as shown in FIG. 4 (a), if the same ID conversion method as in FIG. 3 (a) is applied, threshold = 32, so identification IDs # 0 to # 9 belonging to group 0 and group The identification IDs # 10 to # 31 belonging to 1 are not converted, and only the identification IDs # 32 to # 41 belonging to the group 1 and the identification IDs # 42 to # 63 belonging to the group 0 are ID-converted. Therefore, the number of conversions is minimized, and there are effects of saving power and increasing speed.

On the other hand, when it is desired to assign a priority in band allocation for each identification ID, the order may be changed within the group as shown in FIG. 3B, as shown in FIG. 4B.
With the ID conversion method shown in FIG. 3 and FIG. 4, it is possible to use differently depending on whether the allocation ID is allocated with the minimum number of conversions or when the allocation ID is allocated with priority assigned to the ID. .

When classifying identification IDs into groups, the number of identification IDs to which one allocation ID is allocated in common, that is, the number of assigned IDs may be arbitrarily adjusted. FIG. 5 is an explanatory diagram illustrating an example of group classification.
As shown in FIG. 5A, when the number of identification IDs is 9 and the number of groups is 3, the number of identification IDs # 0 to # 2 is all 3 because the number of identification IDs is divisible by the number of groups. The business ID and the identification ID correspond to 1: 3.

On the other hand, as shown in FIG. 5B, when the number of identification IDs is 4 and the number of groups is 3, since the number of identification IDs cannot be divided by the number of groups, a fraction occurs. In this case, the assigned number of allocation ID # 0 is 3, and the allocation ID and identification ID correspond to 1: 3. However, since the assigned number of allocation ID # 1 is 1, 1: 1 Will be supported.
Thus, by arbitrarily adjusting the number of assigned IDs, each identification ID can be classified into a preset number of groups.

[Band control part]
Based on the bandwidth request signal output from the ID conversion unit 14, the bandwidth control unit 15 controls the bandwidth for the allocation ID output from the ID conversion unit 14 among a plurality of preset allocation IDs. A function of allocating a communication band consisting of a time interval set by time division in the period as an upstream band, and a function of generating a transmission permission signal from the allocated upstream band and allocation ID and outputting the transmission permission signal to the ID converter 14. doing.

  In addition, the bandwidth control unit 15 is configured by dedicated hardware that performs bandwidth allocation for an allocation ID equal to or less than a preset number of presets, and is set within a bandwidth control cycle when allocating an upstream bandwidth. For each allocation period of each group, it has a function of allocating an upstream band composed of a time interval set by time-sharing the allocation period to an allocation ID corresponding to an identification ID belonging to the group.

  FIG. 6 shows an example of ID assignment. For example, when the number of IDs for allocation is 32 (assignment IDs # 0 to # 31), the threshold value = 32. Therefore, when the number of identification IDs is equal to or less than the threshold value, bandwidth allocation processing for all individual IDs can be performed by this hardware. When the identification ID is larger than the threshold value, as described above, the ID conversion unit 14 converts each identification ID into an allocation ID from # 0 to # 31. At this time, as shown in FIG. 6, each identification ID is set to a group composed of allocation IDs # 0 to # 31, and the bandwidth control unit 15 performs an allocation calculation for each group by hardware. The upstream band of the business ID is determined.

[Operation of First Embodiment]
Next, the operation of the station side communication apparatus 10 according to the present embodiment will be described with reference to FIG. FIG. 7 is a sequence diagram illustrating an uplink bandwidth allocation operation according to the first embodiment.

  The station-side communication device 10 sequentially sets a band request signal reception period and an uplink data reception period (allocation period) from each group. Here, the sum of the band request reception period and the uplink data reception period of all groups is the band control period of all IDs, and the minimum value and the maximum value are generally set as described above. The bandwidth request reception period and the uplink data reception period of each group can be freely assigned within the bandwidth control period of all IDs, for example, by setting a maximum value and a minimum value in proportion to the number of IDs of each group.

  After receiving the band n request signal of group n, the station side communication device 10 performs request amount acquisition, allocation calculation, and creation of a transmission permission signal, and transmits the created transmission permission signal to the subscriber side communication device 20 of group n. . The bandwidth control unit 15 holds the end time of the uplink data reception period assigned to the group n, and performs allocation calculation using the held end time as the head of the assignment time at the next assignment.

  Here, it is assumed that the bandwidth control unit 15 in the present embodiment may perform various allocation calculations as shown in the related art singly or in combination. For example, as shown in Non-Patent Document 2, the amount of uplink traffic transmitted by the subscriber side communication device 20 is measured for each ID by the signal processing unit 13 and output to the ID conversion unit 14. The ID may be output to the bandwidth control unit 15 after the ID conversion, and the bandwidth control unit 15 may allocate the uplink data transmission period using the uplink traffic volume. Alternatively, only the group 0 may be a fixed band to which a preset band is allocated, and the group 1 may determine the allocation amount using the uplink traffic amount.

  Also, the bandwidth request signal transmission period is assigned to, for example, an identification ID that has received the bandwidth request signal in the station side communication device 10 or an identification ID that is linked up using an ID conversion table held by the ID conversion unit 14 or the like. For example, various methods shown in the related art may be used in combination. When using link-up information, for example, the link-up information is acquired by the signal processing unit 13 and notified to the ID conversion unit 14. The ID conversion unit 14 converts the identification ID and the allocation ID, and then the bandwidth control unit 15. The bandwidth control unit 15 may output the bandwidth request signal transmission period. The allocation of the band request signal may be started after the end of the band request signal reception period, or may be performed after the end of the allocation of the upstream data reception period of the previous group without waiting for it.

  Here, the uplink data transmission period assigned to the group may be different, or the frequency of assignment may be changed. For example, the amount of allocation to IDs belonging to group 0 can be increased by setting the uplink data reception period of group 0 to be longer than that of other groups. Allocation to group 0 is performed every cycle, allocation to other groups is performed every other cycle (the L cycle is all groups, the L + 1 cycle is only group 0, the L + 2 cycle is all groups, and so on. (Assignment of all groups to group 0) may be increased to a specific group. As described above, the groups need not be set in the order of ID.

  FIG. 8 shows another example of ID assignment. As shown in FIG. 8, the identification IDs # 0 to # 9 and the identification IDs # 42 to # 63 are group 0, the identification IDs # 10 to # 41 are group 1, and the priority of assignment to the groups 0 and 1 You may make a difference. Further, by assigning a small number of identification IDs to group 0, the allocation to the identification IDs belonging to group 0 may be increased. By doing so, it becomes possible to increase the allocation amount of an arbitrary identification ID.

  The identification ID may belong to a plurality of groups. For example, by assigning identification ID # 0 to group 1 and group 2, it is possible to assign priority over other identification IDs.

  The group may be changed. For example, after reading the ID conversion table in the Mth cycle, or after outputting the allocation result of all IDs from the ID conversion unit 14 to the signal processing unit 13, the ID conversion table is rewritten to change the identification ID # 0 to group 0 (for allocation). ID # 0) is changed to group 1 (assignment ID # 1), and identification ID # 1 is changed from group 1 (assignment ID # 1) to group 0 (assignment ID # 0).

  Thereafter, a fixed band may be allocated to the identification ID # 1 during the allocation calculation of the group 0 in the M + 1 period, and a fixed band may be allocated to the identification ID # 0 during the allocation calculation of the group 1. Also, when changing to a group after the group to which it belongs within the band control period, such as identification ID # 0, the band request signal of identification ID # 0 received in the M + 1 period is held and used The band allocation calculation may be performed.

  As described above, from the M + 2 period, the identification ID # 0 can transmit the uplink signal during the allocation period of the group 1, and the identification ID # 1 can transmit the uplink signal during the allocation period of the group 0. Thus, in the present invention, the group of each identification ID and the allocation ID can be arbitrarily and dynamically changed. Using this, an identification ID having a smaller allocated amount than the requested amount is selected in the previous cycle, and an allocation ID for preferentially allocating bandwidth within the group (for example, allocation is performed when a fixed bandwidth is allocated from allocation ID # 0). If the ID is changed to ID # 0) or changed to a higher priority group, the allocation amount can be increased in the next period.

  In addition, when the number of IDs and the request amount of a specific group are extremely small, even if the request amount is allocated as it is, the bandwidth may be wasted because it falls below the minimum value of the uplink data reception period. In order to avoid this, the IDs belonging to the group are changed so that the number of IDs or the total amount of requests is equal or more than a certain threshold between groups (for example, in the case of the total amount of requests, the uplink data reception period minimum value). May be.

  Here, a group having a large number of IDs and a large amount of allocation of the uplink data reception period may be arranged at the head in the band control period, assuming that the allocation amount of the uplink transmission signal varies greatly with the variation of the total amount of requests. . By doing so, when the requested amount of the first group is small and the bandwidth is left, the maximum value of the uplink data reception period of the subsequent group can be increased to increase the allocated amount.

[Effect of the first embodiment]
As described above, according to the present embodiment, the ID conversion unit 14 converts the identification ID acquired from the subscriber side communication device 20 by the signal processing unit 13 into the allocation ID and notifies the bandwidth control unit 15 of the identification ID. The ID for allocation corresponding to the upstream band allocated by the unit 15 is converted into an identification ID and notified to the signal processing unit 13, and the ID is classified into a plurality of groups with a number equal to or less than a preset number at the time of conversion. For each of these groups, the identification ID and the allocation ID belonging to the group are converted in a one-to-one correspondence, and each group set within the bandwidth control period when the bandwidth control unit 15 assigns the upstream bandwidth. For each allocation period, an uplink band composed of a time interval set by time-sharing the allocation period is allocated to an allocation ID corresponding to an identification ID belonging to the group.

  As a result, the number of identification IDs belonging to one group is equal to or less than the set number that can be processed by the bandwidth control hardware of the bandwidth control unit 15. Therefore, for each of these groups, the identification ID belonging to the group is converted into the allocation ID on a one-to-one basis, and the time interval set by time-sharing the allocation period of the group is the allocation ID, that is, the identification ID. Will be allocated as the upstream bandwidth.

  For this reason, in the conventional example, if the number of IDs in the bandwidth control unit is increased in accordance with the increase in the number of branches, the hardware scale increases. However, according to the present embodiment, the hardware design is performed without increasing the hardware scale. Uplink bandwidth can be assigned to a larger number of identification IDs than the set number of times. Therefore, when the performance of the receiver is improved or the distance between the station side communication device 10 and the subscriber side communication device 20 is short, it is necessary to cope with the number of branches exceeding the number set at the time of hardware design. However, it becomes possible to respond flexibly. As a result, the cost and power consumption of the station side communication device 10 and the communication system 1 as a whole can be reduced. In addition, network equipment such as the optical fiber L and the optical splitter SP can be shared by more subscriber-side communication devices 20, which can contribute to cost reduction in the entire communication system 1.

  Also, in this embodiment, by changing the group of identification IDs with a difference in the sum of the bands allocated to each group, etc., not only assignments that are closed to the groups but also assignments that give priority among all IDs It can be carried out. At that time, the band can be effectively used by grouping according to the number of identification IDs and the like.

[Second Embodiment]
Next, with reference to FIG. 9, the station side communication apparatus 10 concerning the 2nd Embodiment of this invention is demonstrated. FIG. 9 is a sequence diagram illustrating an uplink bandwidth allocation operation according to the second embodiment.
Unlike the first embodiment, this embodiment sets the uplink data reception period for all groups after the end of the band request reception period for all groups. As in the first embodiment shown in FIG. 7, the end time of the uplink data reception period assigned last in the bandwidth control period for all IDs is held, and the end time held in the next period is set as the assigned time. Assignment calculation is performed as the head.

  First, the bandwidth request transmission periods of all groups are allocated from the beginning of the allocation time by the various methods shown in the first embodiment. For example, a bandwidth request transmission period is assigned to an identification ID linked up using an ID conversion table or the like held by the ID conversion unit 14. When the allocation of the bandwidth request signal transmission period of all groups is completed, the bandwidth request reception period end time of the last allocated group is set as the start time of the uplink data reception period of the first group, as in the first embodiment, The uplink data transmission period of each ID is assigned using the request amount notified by the bandwidth request signal.

  The second and subsequent groups are also assigned with the end time of the uplink data reception period of the previous group as the start time of the uplink data reception period. Here, the allocation of the bandwidth request signal may be started after the end of the bandwidth request signal reception period as in the first embodiment, or after the end of the allocation of the upstream data reception period of the previous group without waiting for it. You may go.

  Also in the present embodiment, it is assumed that the group and the allocation ID may be changed as in the first embodiment. In the present embodiment, since the band request signal for all IDs is first received in the band control cycle, the allocation calculation of the uplink data transmission period may be performed after that, and the group or The allocation ID can be changed and the allocation calculation for the uplink data transmission period can be performed.

  For example, after the requested amounts of all IDs are held in the memory, the allocation calculation of the uplink data transmission period is performed. When the number of IDs of a specific group or the total amount of requests is extremely small, the sum of the uplink data transmission periods falls below the minimum value of the uplink data reception periods, and the bandwidth is wasted. In order to avoid this, the IDs belonging to the group are set so that the number of IDs or the total amount of requests is equal among the groups, or equal to or greater than a certain threshold value (for example, in the case of the total amount of request, the uplink data reception period minimum). It may be changed.

Similarly to the first embodiment, a fixed band may be assigned to an ID whose group has been changed, but an uplink data transmission period may be assigned according to the held request amount.
In the present embodiment, unlike the first embodiment, since the allocation calculation of the transmission period of the uplink data can be performed after receiving the band request signal of all IDs, in addition to the effects in the first embodiment, as described above It is possible to set a group and an allocation ID in consideration of the requested amount.

[Extended embodiment]
The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. In addition, each embodiment can be implemented in any combination within a consistent range.

  DESCRIPTION OF SYMBOLS 1 ... Communication system, 10 ... Station side communication apparatus, 11 ... Subscriber side I / F part, 12 ... High-order side I / F part, 13 ... Signal processing part, 14 ... ID conversion part, 15 ... Band control part, 20 ... subscriber side communication device, SP ... optical splitter, L ... optical fiber.

Claims (7)

A station that accommodates a plurality of subscriber side communication devices and allocates an upstream band for uplink signal transmission consisting of a time interval set by time-sharing the bandwidth control period for each identification ID used in these subscriber side communication devices A side communication device,
A bandwidth controller that allocates the uplink bandwidth to a preset number of allocation IDs;
A signal processing unit that obtains the identification ID notified from the subscriber side communication device, and notifies the subscriber side communication device together with the identification ID of the uplink band allocated by the band control unit;
The identification ID acquired by the signal processing unit is converted into the allocation ID and notified to the band control unit, and the allocation ID corresponding to the uplink band allocated by the band control unit is the identification ID. An ID conversion unit that converts the information into the signal processing unit and notifies the signal processing unit,
In the conversion, the ID conversion unit classifies the identification IDs into a plurality of groups with a number equal to or less than the set number, and for each group, the identification ID belonging to the group and the allocation ID are in a one-to-one relationship. And convert by matching,
The bandwidth control unit, when allocating the uplink band, for each allocation period of each group set in the band control period, the uplink band consisting of time intervals set by time-sharing the allocation period, A station-side communication apparatus, which is assigned to an ID for allocation corresponding to an identification ID belonging to a group. In the station side communication apparatus according to claim 1,
The ID conversion unit has an ID conversion table indicating a correspondence relationship between an identification ID and an assignment ID, and converts the identification ID and the assignment ID by referring to the ID conversion table. A station side communication device characterized by the above. In the station side communication apparatus of Claim 2,
The station side communication apparatus, wherein the ID conversion table dynamically changes the correspondence relationship according to an external input. In the station side communication apparatus according to claim 1,
The said ID conversion part is converted into the said allocation ID by deleting the high-order bit of the said identification ID, when converting the said identification ID into the said ID for allocation, The station side communication apparatus characterized by the above-mentioned. In the station side communication apparatus according to claim 1,
The said ID conversion part uses the said identification ID as said ID for allocation, when the number of said identification ID is less than the number of said ID for allocation, The station side communication apparatus characterized by the above-mentioned. In the station side communication apparatus according to claim 1,
The signal processing unit uses a bandwidth request amount included in a bandwidth request notified from the subscriber side communication device or a bandwidth request amount obtained by measuring an uplink traffic amount of the subscriber side communication device as the bandwidth request amount. Output to the control unit,
The station-side communication apparatus, wherein the band control unit performs the band allocation based on the band request amount from the signal processing unit. A station that accommodates a plurality of subscriber side communication devices and allocates an upstream band for uplink signal transmission consisting of a time interval set by time-sharing the bandwidth control period for each identification ID used in these subscriber side communication devices A bandwidth control method used in a side communication device,
A bandwidth control step for allocating the uplink bandwidth to a preset number of allocation IDs;
A signal processing step of obtaining the identification ID notified from the subscriber side communication device and notifying the subscriber side communication device together with the identification ID of the uplink band allocated in the bandwidth control step;
The identification ID acquired in the signal processing step is converted into the allocation ID and notified to the bandwidth control step, and the allocation ID corresponding to the uplink bandwidth allocated in the bandwidth control step is the identification ID. An ID conversion step that converts the signal into the signal processing step and
The ID conversion step classifies the identification ID into a plurality of groups by the number equal to or less than the set number at the time of the conversion, and for each group, the identification ID belonging to the group and the allocation ID are in a one-to-one relationship. And convert by matching,
In the bandwidth control step, when allocating the uplink bandwidth, for each allocation period of each group set within the bandwidth control period, the uplink bandwidth consisting of a time interval set by time-sharing the allocation period, A bandwidth control method characterized by allocating each of IDs corresponding to identification IDs belonging to a group.

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