JP2017158032A - Terminal apparatus and transmission order determination method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine a transmission order of a termination device so as to reduce the deviation of a transmission standby time.SOLUTION: A terminal apparatus is connected to a plurality of termination devices. A transmission order determination part acquires information of a transmission order or a transmission data amount when there is transmission data of termination devices in a plurality of periods, and determines the transmission order of the termination device on the basis of an average of the transmission order of each termination device or a total of the transmission data amount. A transmission order command part introduces an order of a data transmission to each termination device in accordance with the transmission order determined by the transmission order determination part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a terminal station apparatus and a transmission order determination method.

  A PON (Passive Optical Network) is configured by connecting an OLT (Optical Line Terminal) and a plurality of ONUs (Optical Network Unit, optical subscriber line network device). FIG. 9 is a diagram illustrating a configuration example of the PON system. In the drawing, the OLT and M ONUs (M is an integer of 2 or more) ONU # 1 to ONU # M are connected by a relay network using an optical fiber and an optical splitter.

  FIG. 10 is a diagram showing a band allocation procedure by a PON system that employs a time division multiplexing (TDM) method. T on the horizontal axis represents time. As shown in the figure, when a data signal is transmitted from ONU # 1 to ONU # M (M = 4 in the figure) to the OLT by time division multiplexing, the OLT permits transmission to ONU # 1 to ONU # M. The control signal to give is transmitted. The transmission permission indicates the time and capacity at which the ONU can transmit a data signal to the OLT. Based on the control signal, the ONU transmits a data signal having a capacity indicated at the time indicated by the OLT to the OLT (see, for example, Non-Patent Document 1). In the figure, the transmission order (time) is specified in the order of ONU # 1, ONU # 4, ONU # 2, ONU # 3 by the control signal.

  When a plurality of ONU # 1 to ONU # 4 are connected to the OLT as shown in the figure, the ONU # 1 that transmitted the data signal first and the ONU # 3 that transmitted the data lastly have the data signal to the OLT. There will be a difference in the time of arrival. This time difference becomes a delay. This time difference is defined as a transmission waiting time. In other words, the transmission standby time is the time that the OLT waits from the arrival time of the data signal transmitted by the ONU having the first transmission order to the arrival time of the data signal transmitted by the ONU having the second and subsequent transmission orders. In other words, the transmission standby time is also the time that the ONU in the transmission order No. 1 transmits from the time when the data signal is transmitted until the ONU in the second transmission order or later transmits the data signal of the own apparatus. A technique for making the delay due to the transmission standby time fair has already been proposed (see, for example, Non-Patent Document 2). It is possible to make the transmission standby time fair among a plurality of ONUs not only by this proposed technique but also by applying a generally known round robin method.

  FIG. 11 is a diagram illustrating an example of data signal transmission in the PON system when the round robin method is used. In the case of the round robin method, the transmission order is shifted after the data transmission of each ONU is completed. The ONU that first transmitted the data signal is set to transmit the data signal last at the next transmission timing, and the transmission order is advanced. In this figure, round robin is performed after one round of transmission of the ONU, but it is possible to achieve fairness in the long run by performing round robin after the transmission is repeated several times. . The period for changing the transmission order is defined as a transmission order fairing period.

International Publication No. 2014/077168

"NTT Technology Journal, Technology Basic Course [GE-PON Technology], 3rd DBA Function", [online], 2005, Nippon Telegraph and Telephone Corporation, [December 21, 2015 search], Internet <http: //www.ntt.co.jp/journal/0510/files/jn200510067.pdf> Junki Miki, Shinichi Aoyagi, Hiromi Ueda, Takashi Watanabe, “Proposal of Shared Access Method in Passive Double Star Optical Access System”, IEICE Transactions B, September 2001, Vol. J84-B, No .9, p.1578-1586 “C-RAN The Road Towards Green RAN”, [online], October 2011, China Mobile Research Institute, [searched February 5, 2016], Internet <http://labs.chinamobile.com/cran/ > “Further Study on Critical C-RAN Technologies”, Next Generation Mobile Networks (NGMN) Alliance, March 2015, version 1.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2”, 3GPP TS 36.300, v12.4.0, December 2014 K. Miyamoto, S. Kuwano, J. Terada, A. Otaka, “Split-PHY Processing Architecture to Realize Base Station Coordination and Transmission Bandwidth Reduction in Mobile Fronthaul”, Optical Fiber Communications Conference and Exhibition (OFC), March 2015 , M2J.4

  There is a case where fairness is not ensured in the PON section when a device connected to the PON system transmits / receives traffic having periodicity different from the transmission order fairing period. As an example corresponding to this case, a case where a mobile radio base station is accommodated by a PON system can be considered. The mobile radio base station has a configuration called C-RAN (Centralized-Radio Access Network). In the C-RAN configuration, the mobile radio base station is separated into a radio antenna unit (RRH: Remote Radio Head) and a signal processing unit (BBU: Baseband Unit), and the BBU-RRH is connected by an optical fiber (for example, Non-Patent Document 3). It has been studied to configure this BBU-RRH with a PON topology (see, for example, Patent Document 1). Recently, a C-RAN configuration has been proposed in which all or a part of physical layer functions are aggregated in the RRH and functions higher than the MAC layer are aggregated in the BBU (see Non-Patent Documents 4 and 6). In the systems such as Non-Patent Document 4 and Non-Patent Document 6, the RRH demodulates the data signal for each subframe, further performs decoding in some cases, and transfers the data signal to the BBU. FIG. 12 shows a sequence example for transferring a data signal assumed in this method.

  FIG. 12 is a diagram illustrating a sequence example in which the RRH transfers the data signal received from the wireless terminal to the BBU. The RRH demodulates and decodes the signal received from the wireless terminal. The signal demodulated and decoded in the RRH is queued for each subframe length and transferred to the BBU. In the case of an LTE (Long Term Evolution) mobile system, the subframe length is 1 ms (see Non-Patent Document 5). For this reason, the period at which data queuing starts when the data signal is transferred from the RRH to the BBU is 1 ms. Data is queued and transferred to the RRH with 1 ms as one cycle.

  FIG. 13 is a diagram showing a transfer sequence when the mobile radio base station is accommodated in the PON system. The ONU transmits the mobile system data received from the RRH to the OLT using a band allocated within the transmission period in accordance with the transmission period of the PON data signal. When the allocated bandwidth in the transmission cycle is smaller than the data amount of the mobile system, the ONU performs transmission over the next transmission cycle.

  As in the above example, when connected devices have periodicity, the order of data transmission from each ONU may not be fair in the PON system. FIG. 14 is a diagram showing the ONU transmission order and the transmission data amount when the mobile radio base station is accommodated in the PON system. This figure shows a case where the bandwidth allocated to the ONU is applied to a plurality of transmission order fairing cycles. For example, when the data signal transmission cycle of the connected device (RRH) is 1 ms and the transmission order fairing cycle is 250 μs, the number of ONUs connected to the OLT is 2, 4, 8,. In the case of transmission cycle / integer multiple of transmission order fairing cycle), traffic is unevenly distributed at the head of the subframe cycle every 1 ms. As shown in FIG. 14, the traffic is concentrated at the timing of the transmission order fairing cycle of ONU # 1, ONU # 2, ONU # 3, ONU # 4, and the transmission order is not fair. In other words, as described above, when the queued data cannot be transmitted in one transmission order fairing period due to the concentration of traffic, the ONU transmits data over the next transmission order fairing period. To do. However, in round robin, a transmission order is assigned regardless of the presence or absence of data to be transmitted. Therefore, an ONU with data to be transmitted may have a later transmission order than an ONU with no data to be transmitted. Therefore, an ONU having a long transmission standby time may occur. In addition, the average transmission order of each ONU may be biased.

  In view of the above circumstances, an object of the present invention is to provide a terminal station apparatus and a transmission order determination method that can determine the transmission order of the termination apparatuses so as to reduce the bias of the transmission standby time.

  One aspect of the present invention is a terminal device connected to a plurality of terminal devices, and acquires transmission order information or transmission data amount information when there is transmission data of each of the terminal devices in a plurality of cycles, A transmission order determining unit that determines a transmission order of the termination device based on an average of the transmission order of each of the termination devices or a total of the transmission data amount, and the termination device according to the transmission order determined by the transmission order determination unit A transmission order command unit for instructing the order of data transmission.

  Further, one aspect of the present invention is the terminal device described above, wherein the transmission order determination unit determines the transmission order of the termination devices in the order from the lowest transmission order or the smallest total transmission data amount. decide.

  Also, one aspect of the present invention is the above-described terminal device, wherein the transmission order determination unit obtains data transmission order information and transmission data amount information of each of the terminal devices in a plurality of cycles, and For each terminating device, the presence or absence of transmission data is determined based on the amount of transmission data in each period, and the average of the transmission order in the period determined to have transmission data is calculated.

  One aspect of the present invention is the terminal device described above, wherein the transmission order determination unit calculates an average difference in transmission order between the different terminal devices, and the sum of the differences exceeds a threshold value The transmission order of the termination device is newly determined.

  Further, one aspect of the present invention is the terminal device described above, wherein the transmission order determination unit acquires the transmission data amount based on the data amount received from the termination device.

  One aspect of the present invention is the terminal device described above, wherein the transmission order determining unit acquires the transmission data amount based on a bandwidth requested from the terminal device, and the transmission order determining unit A data amount acquisition unit to be notified is further provided.

  In the above-described terminal station device, the period is a period for changing the transmission order of the termination devices.

  Further, one aspect of the present invention is a transmission order determination method executed by a terminal device connected to a plurality of terminal devices, information on transmission order when there is transmission data of each of the terminal devices in a plurality of periods, or In the transmission order determination step of acquiring transmission data amount information, and determining the transmission order of the termination devices based on the average of the transmission sequences of the termination devices or the total transmission data amount, and the transmission order determination step A transmission order command step for instructing the terminal device in the order of data transmission according to the determined transmission order.

  According to the present invention, it is possible to determine the transmission order of the terminal devices so as to reduce the bias of the transmission standby time.

It is a figure which shows the structural example of the network system by the 1st Embodiment of this invention. It is a block diagram which shows the structure of OLT by the embodiment. It is a flowchart which shows the operation | movement algorithm of OLT by the embodiment. It is a block diagram which shows the structure of OLT by 2nd Embodiment. It is a figure which shows the sequence of the report of the report information in the network system by the embodiment. It is a block diagram which shows the structure of OLT by 3rd Embodiment. It is a flowchart which shows the operation | movement algorithm of OLT by the embodiment. It is a block diagram which shows the structure of OLT by 4th Embodiment. It is a figure which shows the structural example of a PON system. It is a figure which shows the procedure of the band allocation by the PON system which employ | adopts a time division multiplexing system. It is a figure which shows the example of the data signal transmission in a PON system at the time of using a round robin system. It is a figure which shows the example of a sequence which RRH transfers the data signal received from the radio | wireless terminal to BBU. It is a figure which shows the sequence of the transfer when a mobile radio base station is accommodated in the PON system. It is a figure which shows the transmission order and transmission data amount of ONU when a mobile radio base station is accommodated in the PON system. It is a block diagram which shows the structure of OLT to which embodiment of this invention is not applied.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing a configuration example of a network system 1 according to the first embodiment of the present invention. In the network system 1 shown in the figure, for example, the PON system shown in FIG. 9 relays data between connected external devices that are external devices connected to the PON system. The PON system includes an OLT (Optical Line Terminal; optical subscriber line terminator) 100 as a terminal device and M units (M is an integer of 2 or more) ONUs (Optical Network Unit, optical subscriber line) as terminators. Network device) 200. In the following, a case where the connected external device is a BBU (signal processing unit: Baseband Unit) 610 and an RRH (antenna unit: Remote Radio Head) 620 of the mobile radio base station will be described as an example. It is not limited to mobile radio base stations. Hereinafter, the m-th ONU 200 (m is an integer of 1 to M) is also referred to as ONU 200 # m.

  The OLT 100 and the M ONUs 200 are connected by distributing a plurality of communication signals transmitted through one optical fiber 710 by an optical splitter 720. The OLT 100 multiplexes and transmits a signal (downlink signal) to be transmitted to the M ONUs 200 using a TDM (time division multiplexing) method, and the optical splitter 720 transfers the multiplexed downlink signal to each ONU 200 as it is. Signals (upstream signals) transmitted from the M ONUs 200 to the OLT 100 are multiplexed by the optical splitter 720 and transmitted to the OLT 100.

  In the present embodiment, when the bandwidth transmitted from the ONU 200 to the OLT 100 is shared by a plurality of ONUs 200 by time division, the order in which the ONUs 200 transmit data is balanced so that the transmission standby time is not biased. Therefore, the OLT 100 monitors the transmission order of the data signals transmitted from each ONU 200, and changes the transmission order so that the delay is not biased when the transmission order is unfair.

  FIG. 15 is a block diagram illustrating a configuration of an OLT 900 to which the present embodiment is not applied. In the figure, the OLT 900 includes a downstream frame processing unit 920, an E / O data amount acquisition unit 930, an O / E data amount acquisition unit 940, an upstream frame processing unit 950, and a transmission order command unit 960. Composed.

  The downlink frame processing unit 920 converts the downlink signal frame received from the BBU 610 into a frame used in the PON system. The E / O data amount acquisition unit 930 converts the downlink signal frame-converted by the downlink frame processing unit 920 from an electrical signal to an optical signal, and outputs it to the optical fiber between the ONU. The O / E data amount acquisition unit 940 receives an optical signal transmitted through an optical fiber with the ONU, converts the optical signal into an electrical signal, and outputs the electrical signal to the upstream frame processing unit 950. The upstream frame processing unit 950 converts the frame of the upstream signal converted into the electrical signal by the O / E data amount acquisition unit 940 from the PON frame to a desired frame, and outputs the frame to the BBU. The transmission order command unit 960 generates a transmission order instruction signal and transmits it to the ONU 200. The transmission order instruction signal is a control signal for instructing the transmission order by designating the timing at which the ONU 200 is permitted to transmit the uplink signal by time or the like.

  FIG. 2 is a block diagram showing a configuration of the OLT 100 according to the first embodiment of the present invention. The OLT 100 includes a downstream frame processing unit 120, an E / O data amount acquisition unit 130, an O / E data amount acquisition unit 140, an upstream frame processing unit 150, a transmission order determination unit 160, and a transmission order instruction unit 170. It is configured with. The downlink frame processing unit 120, the E / O data amount acquisition unit 130, the O / E data amount acquisition unit 140, the uplink frame processing unit 150, and the transmission order command unit 170 are respectively represented by the downlink frame processing unit 920, E / The O data amount acquisition unit 930, the O / E data amount acquisition unit 940, the upstream frame processing unit 950, and the transmission order command unit 960 have the same functions. The transmission order determination unit 160 calculates an index value representing the fairness of the transmission order of the ONU 200. If the transmission order determination unit 160 determines that the transmission order is not fair based on the index value, the transmission order determination unit 160 calculates the transmission order of each ONU 200 and outputs the calculation result to the transmission order command unit 170. The transmission order command unit 170 determines the transmission timing of the uplink data of each ONU 200 according to the transmission order of the ONU 200 notified as the calculation result from the transmission order determination unit 160, and sends a transmission order instruction signal indicating the determined transmission timing to the ONU 200. Send.

FIG. 3 is a flowchart showing an operation algorithm of the OLT 100 of the present embodiment.
First, the transmission order determination unit 160 acquires the number of ONUs M, which is the number of ONUs 200 connected to the own apparatus (step S105). Next, the transmission order determining unit 160 sets the number N of transmission order fairing periods for acquiring information and the fairness determination threshold value _Dth in order to determine the fairness of the transmission order. Further, the transmission order determining unit 160 sets an initial value N to the number N (x) of transmission order fairing periods at which each ONU 200 transmits data in the first to Nth transmission order fairing periods (step S110). ). Here, x (x is an integer from 1 to M) indicates the number of the ONU 200. That is, the xth ONU 200 is the ONU 200 # x.

  The transmission order command unit 170 of the OLT 100 performs a fair control such as a round robin method as an initial operation (step S115). The transmission order determining unit 160 calculates an index value indicating whether the transmission order of each ONU 200 is set to fair after the transmission order fairing period reaches N times. Therefore, the transmission order determining unit 160 determines the data amount V (x, n) and the transmission order O of each of the ONU 200 # 1 to ONU200 # m for each transmission order fairing period from the first transmission order fairing period to the Nth transmission order. (X, n) is acquired. n (an integer greater than or equal to 1 and less than or equal to N) is a variable representing the number of transmission order fairing periods among N transmission order fairing periods. The data amount V (x, n) is the amount of data transmitted from the ONU 200 # x to the OLT 100 during the nth transmission order fairing period. The transmission order O (x, n) is the data transmission order of the ONU 200 # x in the n-th transmission order fairing period.

  The transmission order determination unit 160 selects M ONUs 200 one by one (step S125), and executes the following steps S130 and S135. Let x be the number of the ONU 200 selected in step S125.

  The transmission order determining unit 160 acquires the transmission orders O (x, 1) to O (x, N) of the 1st to Nth transmission cycles instructed from the transmission order command unit 170 to the ONU 200 # x. Further, the transmission order determining unit 160 acquires the data amounts V (x, 1) to V (x, N) received from the ONU 200 # x in each of the 1st to Nth transmission periods from the upstream frame processing unit 150.

The transmission order determination unit 160 sets O (x, n) = 0 when V (x, n) = 0. Also, the transmission order determining unit 160 obtains the number L (x) of transmission order fairing periods with V (x, n) = 0, and sets the value of N (x) to N (x) −L ( x) is updated (step S130). The transmission order determining unit 160 calculates the average value W _x of the transmission order of the ONU 200 # x when there is transmission data for N transmission order fairing periods according to the following equation (1) (step S135).

As described above, the transmission order determination unit 160 calculates W _x for all M ONUs 200 connected to the OLT 100. The closer the difference in W _x between the M ONUs 200 is, the higher the fairness is.
As shown in the following formula (2), a difference in W _x between ONU 200 # i and ONU 200 # j (j ≠ i) is D _ij (i, j is an integer of 1 or more and M or less).

If D _ij is close to 0, the fairness is high. The transmission order determining unit 160 obtains the sum of D _ij for all combinations of ONUs 200 as shown in the following equation (3), and uses it as an index value indicating whether the transmission order is set fairly (step S140). .

Transmission order determination unit 160, the index value D determines whether the threshold _{D th} is larger than (step S145). Transmission order instruction unit 170, when the index value D is equal to or smaller than the threshold _{D th} (step S145: NO), it is determined that there is a high fairness. The transmission order command unit 170 continues to use the current ONU 200 transmission order.

On the other hand, the transmission order determination unit 160, if the index value D has a value greater than the threshold _{D th} (step S145: YES), _{W x} is re-sort the sending order of each ONU200 in decreasing order (step S150). The transmission order determination unit 160 outputs the order of the new ONU 200 after the re-sorting to the transmission order command unit 170. The transmission order command unit 170 performs fair control such as round robin based on the order of the ONUs 200 after the re-sorting.

Note that the determination threshold value D _th varies depending on the number N of transmission order fairing cycles, and thus may be a variable of N.
The transmission order determination unit 160 can also determine the transmission order of each ONU 200 based on the order in which data signals are sent from the ONU 200 to the OLT 100. In this case, the transmission order determination unit 160 acquires information on the transmission order of each ONU 200 from the upstream frame processing unit 150. Since the transmission order of the ONUs 200 is determined within the OLT 100, the transmission order determination unit 160 can also read the information in the OLT 100 from the transmission order command unit 170 as described above.

(Second Embodiment)
In the first embodiment, the data amount V (x, n) transmitted from each ONU 200 is acquired based on the data signal from the ONU 200 received by the upstream frame processing unit 150. In the second embodiment, report information sent from each ONU 200 is used instead of the data amount V (x, n) referred to in the first embodiment. The report information is information transmitted from the ONU 200 when the OLT 100 allocates a bandwidth to each ONU 200, and a bandwidth requested by the ONU 200 is set. Below, the difference with 1st Embodiment is demonstrated. The configuration of the network system of this embodiment is a configuration in which the OLT 100 in the network system 1 shown in FIG. 1 is replaced with an OLT 100a shown in FIG.

  FIG. 4 is a block diagram showing a configuration of the OLT 100a according to the second embodiment. In this figure, the same parts as those of the OLT 100 according to the first embodiment shown in FIG. The OLT 100a differs from the OLT 100 shown in FIG. 2 in that a data amount acquisition unit 155 is further provided. The data amount acquisition unit 155 acquires report information received from each ONU 200 from the upstream frame processing unit 150. The data amount acquisition unit 155 converts the requested bandwidth information set in the acquired report information into a data amount V (x, n), and outputs the data amount to the transmission order determination unit 160. For example, the requested bandwidth information may be the data amount itself, or the bandwidth per unit time or per transmission order fairing period.

FIG. 5 is a diagram showing a report information notification sequence in the network system of the present embodiment.
Each ONU 200 transmits a report signal in which report information is set to the OLT 100a in order to request bandwidth allocation. When there is no data to be transmitted to the OLT 100a, the ONU 200 transmits report information indicating that there is no requested bandwidth. When the ONU 200 receives data to be transmitted to the OLT 100a from the RRH 620, the ONU 200 stores the received data in a buffer. The ONU 200 sets a requested bandwidth corresponding to the buffered data amount in the report information and transmits a report signal.

  The data amount acquisition unit 155 of the OLT 100a acquires report information from the report signal received by the upstream frame processing unit 150. The data amount acquisition unit 155 outputs the report information to the transmission order command unit 170, calculates the transmission data amount from the ONU 200 that is the transmission source of the report signal based on the request band set in the report information, and transmits the transmission order. The data is output to the determination unit 160. The operations of the transmission order determination unit 160 other than receiving the data amount from the data amount acquisition unit 155 are the same as those in the first embodiment. The transmission order command unit 170 determines the allocated bandwidth of each ONU 200 based on the requested bandwidth set in the report information received from each ONU 200. The transmission order command unit 170 determines the transmission time of the upstream signal of each ONU 200 based on the determined allocated bandwidth of the ONU 200 and the transmission order of the ONU 200 notified from the transmission order determination unit 160. The transmission order command unit 170 transmits to each ONU 200 a transmission permission signal in which the transmission time and allocated bandwidth of the ONU 200 are set. The ONU 200 transmits the buffered uplink data to the OLT 100a according to the allocated bandwidth and the transmission order notified by the transmission permission signal.

(Third embodiment)
In the first embodiment and the second embodiment, fairness control of the transmission order is performed based on the data transmission order O (x, n). However, even if the transmission order is made fair, the transmission standby time may vary depending on the amount of data transmitted from each ONU. For example, it is assumed that a PON system having a usable bandwidth of 10 Gbps (gigabit per second) accommodates ONU 200 # 1, ONU 200 # 2, ONU 200 # 3, and ONU 200 # 4. Assuming that ONU 200 # 1 and ONU 200 # 2 always occupy 1 Gbps or more and ONU 200 # 3 and ONU 200 # 4 use a bandwidth of about several Mbps, even if the transmission order is made fair, ONU 200 # 3 and ONU 200 The transmission waiting time of # 4 is longer than ONU200 # 1 and ONU200 # 2. This shows that the transmission standby time is not faired. Therefore, in this embodiment, the transmission order is determined based on the data amount V (x, n) of the signal transmitted from each ONU 200. Below, it demonstrates centering on the difference with 1st Embodiment.

The configuration of the network system of this embodiment is a configuration in which the OLT 100 in the network system 1 shown in FIG. 1 is replaced with an OLT 100b shown in FIG.
FIG. 6 is a block diagram showing a configuration of the OLT 100b according to the third embodiment. In this figure, the same parts as those of the OLT 100 according to the first embodiment shown in FIG. The OLT 100b differs from the OLT 100 shown in FIG. 2 in that a transmission order determining unit 160b is provided instead of the transmission order determining unit 160. The transmission order determining unit 160b determines the transmission order based on the data amount V (x, n) of the signal transmitted from each ONU 200.

  FIG. 7 is a flowchart showing an operation algorithm of the OLT 100b of the present embodiment. First, the transmission order determination unit 160b acquires the number of ONUs M, which is the number of ONUs 200 connected to the own device (step S305). Next, the transmission order determining unit 160b sets the number N of transmission order fairing periods for acquiring information (step S310). The transmission order command unit 170 performs fair control such as a round robin method as an initial operation (step S315). The transmission order determining unit 160b determines the transmission order of each ONU 200 after the transmission order fairing period reaches N times. Therefore, the transmission order determining unit 160b acquires the data amounts V (x, 1) to V (x, N) received from the ONU 200 # x in each of the 1st to Nth transmission cycles from the upstream frame processing unit 150 ( Step S320).

The transmission order determination unit 160b selects M ONUs 200 one by one (step S325), and executes the following step S340. Let x be the number of the ONU 200 selected in step S320. Transmission sequence determining unit 160b calculates the sum _{S x} of ONU200 transmission sequence fairness period of # x N times the data volume V (x, n) (step S330).

Transmission order determination unit 160b, only the number portion of ONU200 of M board that connects to calculate the sum _{S x.} Transmission sequence determining unit 160b compares the respective sum _S 1 to S _M between each ONU200 # 1~ONU200 # M, the sum _{S x} is sorted ONU 200 in ascending order as the transmission order (step S335). For example, in a PON system that accommodates ONU200 # 1, ONU200 # 2, ONU200 # 3, and ONU200 # 4, when S ₁ <S ₃ <S ₂ <S ₄ , the transmission order of ONU 200 # 1 and ONU 200 # 3 Are set to the first and second, and ONU 200 # 2 and ONU 200 # 4 are set to the third and fourth. The transmission order determining unit 160b fixes the transmission order in this state, and instructs the transmission order command unit 170 to perform fair control such as round robin again after it is determined that the transmission standby time has been made fair.

(Fourth embodiment)
In the third embodiment, the transmission order is changed using information on the data amount V (x, n) acquired from the upstream frame processing unit 150. However, as in the second embodiment, the transmission order is transmitted from the ONU 200. The data amount V (x, n) can be acquired from the report information. Hereinafter, differences from the third embodiment will be described. The configuration of the network system of the present embodiment is a configuration in which the OLT 100 in the network system 1 shown in FIG. 1 is replaced with an OLT 100c shown in FIG.

  FIG. 8 is a block diagram showing a configuration of the OLT 100c according to the fourth embodiment. In this figure, the same parts as those of the OLT 100b according to the third embodiment shown in FIG. The OLT 100c is different from the OLT 100b shown in FIG. 6 in that a data amount acquisition unit 155 is further provided. The data amount acquisition unit 155 performs the same processing as the data amount acquisition unit 155 included in the OLT 100a according to the second embodiment illustrated in FIG. That is, the data amount acquisition unit 155 of the OLT 100c acquires report information set in the report signal received by the upstream frame processing unit 150. The data amount acquisition unit 155 outputs the report information to the transmission order command unit 170, calculates the transmission data amount from the ONU 200 that is the transmission source of the report signal based on the request band set in the report information, and transmits the transmission order. It outputs to the determination part 160b. The subsequent operation is the same as that of the third embodiment.

(Fifth embodiment)
The above-described first to fourth embodiments can be used not only in each but also in any combination.

  As described above, in an OLT (terminal station device) connected to a plurality of ONUs (termination units), the transmission order determination unit determines transmission order information or transmission when there is transmission data for each ONU in a plurality of cycles. Data amount information is acquired, and the transmission order of each ONU is determined based on the average of the transmission order of each ONU or the total transmission data amount. Specifically, the transmission order determination unit determines the transmission order of the ONUs in the order from the lowest average transmission order or the smallest total transmission data amount. Moreover, the said period is a transmission order fairing period which changes the transmission order of ONU. The transmission order determination unit obtains information on the transmission order of data of each ONU and information on the amount of transmission data in a plurality of transmission order fairing periods, and transmits transmission data based on the transmission data amount of each period for each ONU. The average of the transmission order in the period determined to have transmission data is calculated. Further, the transmission order determination unit may calculate an average difference in transmission order between different ONUs, and newly determine the ONU transmission order when the total of the calculated differences exceeds a threshold value. The transmission order determination unit may acquire the transmission data amount based on the data amount received from the ONU. The data amount acquisition unit acquires the transmission data amount based on the bandwidth requested from the ONU, and determines the transmission order. You may notify the department. The transmission order command section of the OLT instructs the ONU to perform the data transmission order based on the transmission order determined by the transmission order determination section.

  Conventionally, due to the periodicity of data signal transmission of a device connected to the PON system, the fairness of the transmission waiting time in the ONU may be impaired in the PON system. According to the above-described embodiment, the transmission order of each ONU is determined based on the transmission order or the data amount of signals transmitted from the ONU so as to reduce the bias in the transmission standby time. Thereby, it is possible to improve the fairness of the transmission waiting time between ONUs due to the transmission order.

  You may make it implement | achieve a part of function of OLT100, 100a, 100b, 100c in embodiment mentioned above with a computer. In that case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory inside a computer system serving as a server or a client in that case may be included and a program held for a certain period of time. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

  It can be used for a system that performs communication by multiple access.

1 Network system 100, 100a, 100b, 100c OLT
120, 920 Downstream frame processing unit 130, 930 E / O data amount acquisition unit 140, 940 O / E data amount acquisition unit 150, 950 Upstream frame processing unit 155 Data amount acquisition unit 160, 160b Transmission order determination unit 170, 960 Transmission Order command part 200 ONU
610 BBU
620 RRH
710 Optical fiber 720 Optical splitter

Claims (7)

A terminal device connected to a plurality of terminal devices,
Obtaining information on the transmission order or information on the amount of transmission data when there is transmission data for each of the termination devices in a plurality of periods, and based on the average of the transmission order of each of the termination devices or the sum of the amount of transmission data A transmission order determination unit that determines the transmission order of the devices;
A transmission order command unit for instructing the order of data transmission to the end device according to the transmission order determined by the transmission order determination unit;
A terminal device comprising: The transmission order determination unit determines the transmission order of the termination devices in the order from the lowest average transmission order or from the smallest total transmission data amount.
The terminal device according to claim 1. The transmission order determining unit obtains information on the transmission order of data of each of the termination devices and information on the amount of transmission data in a plurality of cycles, and transmits transmission data based on the transmission data amount of each cycle for each termination device. Determining the presence or absence, and calculating the average of the transmission order in the period determined to have transmission data;
The terminal device according to claim 1, wherein the terminal device is a terminal device. The transmission order determination unit calculates an average difference in transmission order between the different terminal devices, and newly determines the transmission order of the terminal devices when the sum of the differences exceeds a threshold value.
The terminal device according to any one of claims 1 to 3, wherein: The transmission order determination unit acquires the transmission data amount based on the data amount received from the termination device.
The terminal device according to any one of claims 1 to 4, characterized in that: Further comprising a data amount acquisition unit for acquiring the transmission data amount based on a bandwidth requested from the termination device and notifying the transmission order determination unit;
The terminal device according to claim 1, wherein the terminal device is a terminal device. A transmission order determination method executed by a terminal device connected to a plurality of terminal devices,
Obtaining information on the transmission order or information on the amount of transmission data when there is transmission data for each of the termination devices in a plurality of periods, and based on the average of the transmission order of each of the termination devices or the sum of the amount of transmission data A transmission order determination step for determining the transmission order of the devices;
A transmission order instruction step for instructing the terminal device in the order of data transmission according to the transmission order determined in the transmission order determination step;
A transmission order determination method characterized by comprising:

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