Bandwidth allocation device and bandwidth allocation method

Abstract

The bandwidth allocation device comprises: a service information acquisition unit, which acquires service information showing the service of the communication performed by the lower device via the terminal device for each lower device connected to each terminal device; a service front position detection unit, which detects the front timing of the burst service based on the service information; a service information extraction unit, which extracts information on the service volume of each of a plurality of service allocation periods from the service information acquired for each lower device; a service volume estimation unit, which calculates the average value of the service volume in the service allocation period for each lower device based on the information on the service volume extracted by the service information extraction unit; and a bandwidth allocation unit, which uses the front timing detected by the service front position detection unit as the timing of the front of the bandwidth allocation period, and allocates a first bandwidth, which is the allocated bandwidth based on the average value calculated by the service volume estimation unit, to the terminal device from the front of the bandwidth allocation period.

Description

Technical Field

[0001] The invention relates to a bandwidth allocation device and a bandwidth allocation method.

[0002] This application claims priority based on Japanese Patent Application No. 2017-024284 filed in Japan on February 13, 2017, the contents of which are incorporated herein by reference. Background Art

[0003] There is a wireless communication system that separates the antenna unit (RRH: Remote Radio Head) and the signal processing unit (BBU: Baseband Unit) of a wireless base station. In this wireless communication system, the RRH and BBU are connected via an optical device and an optical fiber, and this optical section is called a mobile fronthaul (MFH). Fig.11 It is a diagram showing a configuration example of MFH.

[0004] In recent years, in order to reduce the cost of MFH, discussions have been conducted on using a TDM-PON (Time Division Multiplexing- Passive Optical Network) system (for example, see Non-Patent Document 1) to accommodate RRH (for example, see Non-Patent Document 2). In the TDM-PON system, a time division multiple access (TDMA) method is used to transmit signals from an optical terminal device (ONU: Optical Network Unit) to an optical terminal station device (OLT: Optical Line Terminal). When using TDM-PON to accommodate RRH, a method has been proposed in which the bandwidth allocated from the optical terminal station device to the optical terminal device is dynamically changed by estimating the amount of traffic transferred to the MFH based on traffic information between the RRH and the wireless terminal (for example, see Non-Patent Document 2).

[0005] Fig.12 This is a block diagram showing the configuration of a conventional terminal station device.

[0006] The service information acquisition unit acquires an uplink signal or a downlink signal for each bandwidth allocation period. Here, the bandwidth allocation period is a period in which a terminal station device (e.g., OLT) sends a signal storing information providing uplink transmission permission to a terminal device (e.g., ONU). The service information extraction unit divides and extracts the service volume acquired by the service information acquisition unit for each arbitrary period. The divided period is defined as a service period. The service volume estimation unit calculates, for each service period, an average μ and a standard deviation σ of the service volume in a plurality of bandwidth allocation periods included in the service period.

[0007] In the RRH connected to the terminal device, Fig.13 As shown in the figure, the wireless signals sent from the wireless terminal are buffered for a certain period of time and demodulated / decoded in batches. As a result, the signal from the RRH to the terminal device (ONU) is a burst service. Fig.14 As shown in the figure, a certain time interval called TTI (Transmission Time Interval) is maintained while reaching the terminal device (ONU). TTI represents the minimum unit of wireless scheduling. The time length of TTI is equal to the length of 1 subframe. In the case of LTE, the cycle of wireless scheduling is 1ms, so 1TTI is 1ms. In the fifth generation mobile communication system (5G) as a future mobile access, the shortening of TTI is discussed.

[0008] The service front position detection unit detects the front position of each burst service by referring to the service information transferred from the service information acquisition unit. The service front position detection unit sends the information of the detected front position to the bandwidth allocation amount calculation unit. The bandwidth allocation amount calculation unit calculates the bandwidth allocation amount and allocation timing based on the information transferred from each of the service volume estimation unit and the service front position detection unit. Fig.15 2 shows the allocation method according to the conventional technology in the bandwidth allocation amount calculation unit. The bandwidth allocation amount calculation unit starts bandwidth allocation from the beginning of TTI as shown in equation (1) and determines the bandwidth allocation amount B of each terminal device based on the average value μ and the standard deviation σ.

[0009] [Formula 1]

[0010] .

[0011] Here, n is a constant calculated by the risk rate. In addition, when the i-th terminal device that obtains the transmission permission is ONU#i, the bandwidth allocation amount B, the average value μ, and the standard deviation σ of ONU#i are recorded as bandwidth allocation amount B （i） , average value μ （i） , standard deviation σ （i） .also, Fig.16 1 is a flowchart showing a bandwidth allocation process in a bandwidth allocation amount calculation unit according to the prior art.

[0012] Prior art literature

[0013] Non-patent literature

[0014] Non-patent document 1: "NTT Technology Forum, Technical Foundation Lecture [GE-PON Technology], 1st PON to this", [online], 2005, Nippon Telegraph and Telephone Corporation, [retrieved on May 21, 2013], Internet<URL http: / / www.ntt.co.jp / journal / 0508 / files / jn200508071.pdf>

[0015] Non-patent literature 2: T. Kobayashi, H. Ou, D. Hisano, T. Shimada, J. Terada and A. Otaka, "Bandwidth Allocation scheme based on Simple Statistical Traffic Analysis for TDM-PONbased Mobile Fronthaul," in Proc. of OFC2016, paper W3C.7, 2016. Summary of the invention

[0016] Problems to be solved by the invention

[0017] In TDM-PON, when multiple ONUs are connected, the OLT provides transmission permission to each ONU in sequence during the bandwidth allocation cycle. Therefore, ONU #N that has received transmission permission after the Nth one is in a standby state until ONU #1 to ONU #(N-1) that have received transmission permission from the 1st to (N-1)th one has completed sending the signal. The longer this standby time is, the more it will cause delay.

[0018] When applying the previous bandwidth allocation, the transmission permission time is longer for the business that occurs. For example, when the average throughput μ of the uplink signal is 100Mbps (megabits per second), the standard deviation σ is 20Mbps, and the constant n=6, the bandwidth allocated is B=100+6×20=220Mbps according to formula (1). However, when considering that the distribution of business occurrence is concentrated near the average throughput, 120Mpbs is allocated to cope with the sudden increase in business. Then, in the ONU that gets the opportunity to send, it is in the transmission standby state until the 220Mbps bandwidth allocation is completed.

[0019] In addition, when the bandwidth allocation operation is being performed, there is a possibility that an ONU that makes a new connection request exists. In TDM-PON, a window called an activation window is set at a certain time. During the period of setting the activation window, the newly connected ONU may send a signal for authentication request to the OLT. In order to prevent the signal sent for the authentication from conflicting with the signal of the connected ONU, the bandwidth allocation is stopped during the activation window. Therefore, in the connected ONU, a delay is instantaneously generated during the activation window.

[0020] In view of the above, an object of the present invention is to provide a bandwidth allocation device and a bandwidth allocation method capable of allocating bandwidth to a terminal device connected to a terminal station device through time division multiple access in a manner that reduces delay.

[0021] Solutions to Solve Problems

[0022] The bandwidth allocation device in the first mode of the present invention comprises: a service information acquisition unit, which acquires service information showing the service that the lower device communicates through each terminal device for each lower device connected to the terminal device; a service head position detection unit, which detects the head timing of the burst service based on the service information; a service information extraction unit, which extracts information on the service volume of each of a plurality of service allocation periods from the service information acquired for each of the lower devices; a service volume estimation unit, which calculates the average value of the service volume in the service allocation period for each of the lower devices based on the information on the service volume extracted by the service information extraction unit; and a bandwidth allocation unit, which uses the head timing detected by the service head position detection unit as the timing of the head of the bandwidth allocation period, and allocates a first bandwidth, which is the allocated bandwidth based on the average value calculated by the service volume estimation unit, to the terminal device from the head of the bandwidth allocation period.

[0023] According to the second mode of the present invention, in the bandwidth allocation device of the first mode, the traffic estimation unit calculates the standard deviation of the traffic volume in the traffic allocation period for each of the lower devices based on the information of the traffic volume extracted by the traffic information extraction unit; the bandwidth allocation unit allocates a second bandwidth, which is an allocated bandwidth based on the standard deviation calculated by the traffic estimation unit, to the terminal device after the allocation of the first bandwidth is completed, and allocates a remaining bandwidth, which is a period from the end of the allocation of the second bandwidth to the end of the bandwidth allocation period, to the terminal device after excluding the first bandwidth and the second bandwidth from the bandwidth that can be allocated in the bandwidth allocation period.

[0024] According to the third mode of the present invention, in the bandwidth allocation device of the second mode, the bandwidth allocation unit calculates the first bandwidth allocated to the terminal device according to the ratio of the average value in each of the terminal devices to the total of the average values ​​in all the terminal devices; and calculates the second bandwidth allocated to the terminal device according to the ratio of the standard deviation in each of the terminal devices to the total of the standard deviations in all the terminal devices.

[0025] According to a fourth aspect of the present invention, the bandwidth allocation device of the second or third aspect further comprises a newly connected terminal device authentication unit, wherein the newly connected terminal device authentication unit sets an authentication period for detecting a newly connected terminal device within the remaining bandwidth allocation period, and the bandwidth allocation unit does not allocate bandwidth to the terminal device within the authentication period notified from the newly connected terminal device authentication unit.

[0026] According to a fifth aspect of the present invention, the bandwidth allocation device of the second or third aspect further comprises an excessive traffic determination processing unit which instructs the bandwidth allocation unit to redo bandwidth allocation when the traffic volume of the uplink signal sent from the terminal device using the second bandwidth exceeds a threshold.

[0027] According to a sixth aspect of the present invention, the bandwidth allocation device of the second or third aspect further comprises an excessive traffic determination processing unit for instructing the bandwidth allocation unit to redo bandwidth allocation when an uplink signal using the remaining bandwidth is transmitted from the terminal device.

[0028] According to the seventh mode of the present invention, in the bandwidth allocation device of the first mode, the bandwidth allocation unit calculates the bandwidth by multiplying the ratio of the average value to the sum of the average values ​​calculated by the traffic estimation unit by the bandwidth allocatable to the lower device for each lower device; the bandwidth allocation unit allocates the bandwidth indicated by the first threshold to the lower device for which the calculated bandwidth exceeds the first threshold, and equally allocates the unallocated bandwidth among the allocatable bandwidth to the lower device for which the calculated bandwidth is below the first threshold.

[0029] According to the 8th aspect of the present invention, in the bandwidth allocation device of the 7th aspect, the bandwidth allocation unit allocates the bandwidth indicated by the first threshold to the lower device for which the calculated bandwidth exceeds the first threshold, allocates the bandwidth indicated by the second threshold to the lower device for which the calculated bandwidth is below the first threshold and above a second threshold which is smaller than the first threshold, and equally allocates the unallocated bandwidth among the allocatable bandwidth to the lower device for which the calculated bandwidth is below the second threshold.

[0030] According to the 9th mode of the present invention, the bandwidth allocation method performed by the bandwidth allocation device comprises: a business information acquisition step of acquiring business information showing the business of the communication performed by the lower device via each terminal device for each lower device connected to the terminal device; a business front position detection step of detecting the front timing of the burst business based on the business information; a business information extraction step of extracting information on the business volume of each of a plurality of business allocation cycles from the business information acquired for each of the lower devices; a business volume estimation step of calculating the average value of the business volume in the business allocation cycle based on the extracted business volume information for each of the lower devices; and a bandwidth allocation step of using the detected front timing of the burst business as the timing of the front of the bandwidth allocation cycle and allocating a first bandwidth as the allocated bandwidth based on the calculated average value to the terminal device from the front of the bandwidth allocation cycle.

[0031] Effects of the Invention

[0032] According to the present invention, it is possible to allocate bandwidth to a terminal device connected to a terminal station device through time division multiple access in a manner that reduces delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a diagram showing the configuration of an access network system according to the first embodiment of the present invention.

[0034] Figure 2 This is a functional block diagram showing the configuration of a terminal station device according to the first embodiment.

[0035] Figure 3 This is a flowchart showing the bandwidth allocation process of the terminal station device according to the first embodiment.

[0036] Figure 4 This is a diagram showing bandwidth allocation to terminal devices according to the first embodiment.

[0037] Figure 5 This is a functional block diagram showing the configuration of a terminal station device according to the second embodiment.

[0038] Figure 6 This is a functional block diagram showing the configuration of a terminal station device according to the third embodiment.

[0039] Figure 7 This is a functional block diagram showing the structure of a terminal station device according to the seventh embodiment.

[0040] Figure 8 This is a flowchart showing the bandwidth allocation process of the terminal station device according to the seventh embodiment.

[0041] Fig. 9This is a functional block diagram showing the structure of a terminal station device according to the eighth embodiment.

[0042] Fig.10 This is a flowchart showing the bandwidth allocation process of the terminal station device according to the eighth embodiment.

[0043] Fig.11 It is a diagram showing a configuration example of a conventional MFH.

[0044] Fig.12 This is a diagram showing the configuration of a terminal station device according to the prior art.

[0045] Fig.13 : is a diagram showing an example of a traffic model in which a burst signal occurs.

[0046] Fig.14 FIG. 1 is a diagram showing an example of services flowing in the MFH.

[0047] Fig.15 This is a diagram showing bandwidth allocation to terminal devices according to the conventional technology.

[0048] Fig.16 1 is a flowchart showing bandwidth allocation processing of a terminal station device according to the conventional technology. DETAILED DESCRIPTION

[0049] Below, while referring to the attached Figure 1 Embodiments of the present invention will be described in detail.

[0050] [First embodiment]

[0051] Figure 1 This is a diagram showing the structure of an access network system 8 according to the first embodiment. The access network system 8 is a structure in which a relay transmission system having a terminal station device 1, a terminal device 2, and an optical splitter 3 accommodates a communication system having an upper device 5 and a lower device 6. Accommodating a communication system refers to communication in the relay communication system.

[0052] The relay transmission system is, for example, an optical relay transmission system such as a PON (passive optical network) system. When the relay transmission system is a PON system, the terminal station device 1 is an optical terminal station device (OLT), and the terminal device 2 is an optical terminal device (ONU). The direction from the terminal station device 1 to the terminal device 2 is downstream, and the direction from the terminal device 2 to the terminal station device 1 is upstream. The optical separator 3 distributes the TDM (time division multiplexing) optical signal transmitted from the terminal station device 1 through one optical fiber 41 to the optical fiber 42 connected to each of the multiple terminal devices 2. In addition, the optical separator 3 combines the TDMA (time division multiple access) optical signal transmitted from the optical fiber 42 connected to each of the multiple terminal devices 2, and outputs it to the optical fiber 41. The terminal station device 1 has a function as a bandwidth allocation device that allocates bandwidth to each terminal device 2, and executes a bandwidth allocation method.

[0053] The communication system is, for example, a mobile network. When the communication system is a mobile network, the upper device 5 is a signal processing unit (BBU) of a wireless base station, and the lower device 6 is an antenna unit (RRH) of the wireless base station. The RRH communicates wirelessly with a mobile wireless terminal by TDD. Furthermore, the relay transmission system can accommodate multiple communication systems.

[0054] Figure 2 1 is a functional block diagram showing the structure of the terminal station device 1, and only functional blocks related to the first embodiment are extracted and shown. The terminal station device 1 includes an upper-level transceiver functional unit 11, a lower-level transceiver functional unit 12, a service information acquisition unit 13, a service information extraction unit 14, a service volume estimation unit 15, a service head position detection unit 16, and a bandwidth allocation amount calculation unit 17. The functions of the upper-level transceiver functional unit 11, the lower-level transceiver functional unit 12, the service information acquisition unit 13, the service information extraction unit 14, the service volume estimation unit 15, and the service head position detection unit 16 are similar to those of the first embodiment. Fig.12 The same is true for the conventional terminal station device shown.

[0055] The upper transceiver function unit 11 is an interface for transmitting and receiving data with the upper device 5. The upper transceiver function unit 11 outputs a downlink signal received from the upper device 5 to the lower device 6 to the lower transceiver function unit 12. In addition, the upper transceiver function unit 11 transmits an uplink signal received from the lower device 6 to the upper device 5 from the lower device 6 to the upper device 5 from the lower transceiver function unit 12 to the upper device 5.

[0056] The lower transceiver function unit 12 is an interface for transmitting and receiving data with the terminal device 2. The lower transceiver function unit 12 converts the downlink signal output from the upper transceiver function unit 11 or the control signal output from the bandwidth allocation amount calculation unit 17 from an electrical signal into an optical signal, and outputs the optical signal to the terminal device 2. In addition, the lower transceiver function unit 12 converts the uplink signal received from the terminal device 2 from an optical signal into an electrical signal, and outputs the electrical signal to the upper transceiver function unit 11. The electrical signal output from the lower transceiver function unit 12 to the upper transceiver function unit 11 includes the uplink signal from the lower device 6 to the upper device 5. Furthermore, the lower transceiver function unit 12 transfers the uplink signal converted into the electrical signal to the service information acquisition unit 13. The lower transceiver function unit 12 may output only the uplink main signal among the uplink signals to the service information acquisition unit 13.

[0057] The traffic information acquisition unit 13 acquires uplink signals from each terminal device 2 for each bandwidth allocation period and stores traffic information indicating the traffic volume of uplink signals for each bandwidth allocation period. The bandwidth allocation period is a period for transmitting a signal storing information that the terminal station device 1 provides uplink transmission permission to the terminal device 2.

[0058] The service information extraction unit 14 divides and extracts the service information obtained by the service information acquisition unit 13 for each arbitrary period. For an arbitrary period, N seconds of service may be equally divided into M parts and N / M may be regarded as one period, or N seconds of service may be not equally divided but divided into M1, M2, ..., M i The different time lengths are divided and each is regarded as one cycle. The divided cycles are service cycles. One service cycle includes a plurality of bandwidth allocation cycles. The service information extraction unit 14 transfers the extracted service information of each service cycle to the service volume estimation unit 15.

[0059] The traffic volume estimation unit 15 obtains the traffic volume of each of the plurality of bandwidth allocation periods included in the traffic cycle from the traffic information for each terminal device 2 for each traffic cycle, and calculates the average value μ and standard deviation σ of the traffic volume. The traffic volume estimation unit 15 transfers the calculation results of the average value μ and standard deviation σ of the traffic volume for each traffic cycle of each terminal device 2 to the bandwidth allocation amount calculation unit 17.

[0060] The service head position detection unit 16 detects the head position of each burst service, and outputs information indicating the detected head position to the bandwidth allocation amount calculation unit 17. The head position of the burst service corresponds to the head of TTI, for example. The bandwidth allocation amount calculation unit 17 calculates the bandwidth allocation amount and allocation timing of each terminal device 2 in the bandwidth allocation period based on the information transferred from each of the traffic volume estimation unit 15 and the service head position detection unit 16.

[0061] Figure 3 This is a process flow showing the operation of the terminal station device 1 .

[0062] First, the bandwidth allocation calculation unit 17 of the terminal station device 1 allocates bandwidth to each terminal device 2 in a fixed manner in each DBA (Dynamic Bandwidth Allocation) cycle for service collection. The DBA cycle is a cycle for allocating bandwidth to the terminal device 2. The lower-level transceiver function unit 12 notifies each terminal device 2 of the fixed bandwidth allocated by the bandwidth allocation calculation unit 17 as the allocated bandwidth for each DBA cycle. Each terminal device 2 sends the uplink data received from the lower device 6 to the terminal station device 1 in accordance with the allocated fixed bandwidth (step S105). The service information acquisition unit 13 of the terminal station device 1 acquires the uplink signal received by the lower-level transceiver function unit 12 over multiple cycles in each bandwidth allocation cycle, and stores the service volume of the uplink signal acquired for each terminal device 2 as service information (step S110).

[0063] After the service monitoring period ends, the service head position detection unit 16 detects the head position of each burst service with reference to the service information, and outputs information showing the detected head position to the bandwidth allocation amount calculation unit 17 (step S115). The service information extraction unit 14 extracts the service information acquired by the service information acquisition unit 13 for each service cycle, and transfers the extracted service information to the service volume estimation unit 15. The service volume estimation unit 15 calculates the average value μ and the standard deviation σ of the service volume in the DBA cycle of each terminal device 2 for each service cycle based on the service information transferred from the service information extraction unit 14, and transfers the calculation result to the bandwidth allocation amount calculation unit 17 (step S120).

[0064] The bandwidth allocation amount calculation unit 17 performs the following processing of step S125 to step S150 for each bandwidth allocation period.

[0065] The bandwidth allocation amount calculation unit 17 reads the average value μ and standard deviation σ of the traffic volume of each terminal device 2 in the traffic cycle corresponding to the bandwidth allocation cycle of the target bandwidth allocation from the traffic volume estimation unit 15 (step S125). The bandwidth allocation amount calculation unit 17 allocates bandwidth B based on the average value μ of the traffic volume as shown in equation (2) to each terminal device 2 in advance. avg (Step S130 ). The superscript (i) indicates the i-th terminal device 2 among the plurality of terminal devices 2 connected to the terminal station device 1 . The traffic cycle used in step S125 is, for example, a traffic cycle that is a predetermined number of times before the target bandwidth allocation cycle.

[0066] [Formula 2]

[0067] .

[0068] Figure 4 2 is a diagram showing the bandwidth allocation to each terminal device 2. Figure 4 As shown in the figure, when the three terminal devices 2 to which the bandwidth is allocated are ONU#1 to ONU#3, the bandwidth allocation amount calculation unit 17 allocates bandwidth B to ONU#1 to ONU#3 in order from the beginning of the DBA cycle. avg （1） ~B avg （3） .

[0069] The bandwidth allocation amount calculation unit 17 calculates the bandwidth B based on the average value of the formula (2) for all the terminal devices 2. avg When allocating (step S135), bandwidth B based on the variance value of the standard deviation σ of the traffic volume is allocated to each terminal device 2 in sequence as shown in formula (3). var (Step S140 ) Note that n is a constant calculated by the hazard rate, and the lower the hazard rate, the larger the value of n.

[0070] [Formula 3]

[0071] .

[0072] exist Figure 4 In the bandwidth allocation shown in FIG. 1 , bandwidth B is allocated to each of the three ONUs # 1 to # 3. avg （1） ~B avg （3） Then, the bandwidth B based on the variance value is allocated var （1） ~B var （3） Furthermore, the bandwidth allocation based on these equations (2) and (3) can be further divided.

[0073] The bandwidth allocation amount calculation unit 17 calculates the bandwidth B of all the terminal devices 2 based on the equation (2). var After the allocation (step S145), the remaining bandwidth B in the DBA cycle is allocated to the terminal device 2. surplus The traffic estimation unit 15 calculates the remaining bandwidth B by equation (4): surplus .

[0074] [Formula 4]

[0075] .

[0076] Here, B all Refers to the full bandwidth available in a TDM-PON during a DBA cycle. For example, in 10G-PON, without considering the overhead, Ball It is 10Gbps (Gigabits per second).

[0077] The bandwidth allocation amount calculation unit 17 uses the remaining bandwidth B calculated by the traffic volume estimation unit 15 to calculate the remaining bandwidth B. surplus Bandwidth is allocated to each terminal device 2 (step S150). surplus In the allocation, a fixed bandwidth can be allocated equally to each terminal device 2, or the bandwidth allocation amount can be changed for each terminal device 2 according to the priority or the like. surplus In addition to being allocated to each terminal device 2, it can also be used as bandwidth for accommodating other services. surplus During this period, the terminal station device 1 and each terminal device 2 can also perform a sleep operation. Figure 4 In the bandwidth allocation shown, the bandwidth B based on the variance value var The remaining bandwidth B is allocated to each ONU#1 to ONU#3 during the period from the end of bandwidth allocation to the end of the DBA cycle. surplus The bandwidth b （1） ~b （3） .

[0078] The order of bandwidth allocation to the terminal devices 2 using equations (2) to (4) may be different. The bandwidth allocation amount calculation unit 17 performs bandwidth allocation based on the average value μ of the traffic volume calculated for each terminal device 2 and bandwidth allocation based on the standard deviation σ of the traffic volume calculated for each terminal device 2. The terminal station device 1 performs these allocations in order, thereby reducing the waiting time (communication delay) before each terminal device 2 obtains a communication opportunity.

[0079] [Second embodiment]

[0080] In the first embodiment, the terminal station device 1 allocates to each terminal device the remaining bandwidth that has not been allocated to any terminal device after allocating the bandwidth based on the average value and the bandwidth based on the variance value. In the second embodiment, the remaining bandwidth or the allocated bandwidth based on the variance value and the remaining bandwidth are used in the activation window in which the newly connected terminal device sends a signal for requesting authentication to the terminal station device. In this way, the terminal station device of the second embodiment can reduce the impact of delay on the already connected terminal devices by setting the activation window only during the period in which the bandwidth is allocated by equation (3) or equation (4) shown in the first embodiment.

[0081] The terminal station device of the second embodiment calculates the average value and standard deviation of the traffic volume based on the uplink traffic information, and uses these to estimate the bandwidth allocation amount of each terminal device. Therefore, the remaining bandwidth B calculated by equation (4) is used. surplusThe allocated bandwidth is essentially unused bandwidth. Therefore, even if an activation window is set during this period, there is no impact on the delay caused to the mobile system.

[0082] Figure 5 2 is a block diagram showing the configuration of a terminal station device 1a according to the second embodiment. Figure 5 In, with Figure 2 The same parts of the terminal station device 1 according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Figure 5 The terminal station device 1 shown is different from the terminal station device 1 of the first embodiment in that it further includes a newly connected terminal device authentication unit 18. The newly connected terminal device authentication unit 18 obtains the period for performing bandwidth allocation using the formula (4) shown in the first embodiment from the traffic volume estimation unit 15 or the bandwidth allocation amount calculation unit 17. The newly connected terminal device authentication unit 18 notifies the bandwidth allocation amount calculation unit 17 that an activation window is set only during this period. The bandwidth allocation amount calculation unit 17 sets the activation window in such a manner that bandwidth is not allocated to the terminal device 2 during the period notified from the newly connected terminal device authentication unit 18 during the period for performing bandwidth allocation using the formula (4) shown in the first embodiment.

[0083] The newly connected terminal device authentication unit 18 may further acquire a period for performing bandwidth allocation using the formula (3) and set an activation window during the period to notify the bandwidth allocation amount calculation unit 17. The bandwidth allocation amount calculation unit 17 sets an activation window during the period notified from the newly connected terminal device authentication unit 18, among the periods for performing bandwidth allocation using the formula (3) shown in the first embodiment, so that no bandwidth is allocated to the terminal device 2 during the period.

[0084] The terminal station device 1a sets an activation window during a period when the possibility of each terminal device 2 sending an uplink signal is low. By setting the activation window in this way, the possibility of a signal related to authentication of a newly connected terminal device conflicting with an uplink signal of each terminal device 2 can be suppressed, thereby reducing the delay in the transmission of the uplink signal.

[0085] [Third embodiment]

[0086] In the third embodiment, the terminal station device corrects the bandwidth allocation amount when traffic significantly larger than the estimated result is generated from the terminal device.

[0087] Figure 6 1 is a block diagram showing the configuration of a terminal station device 1b according to the third embodiment. Figure 6 In, with Figure 2 The same components of the terminal station device 1 according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Figure 6The terminal station device 1 b shown is different from the terminal station device 1 of the first embodiment in that it further includes a traffic determination time threshold processing unit 19 .

[0088] An arbitrary time threshold t is set in the traffic determination time threshold processing unit 19. th When the terminal station device 1 receives an uplink signal transmitted by bandwidth allocation based on equation (3), the service information acquisition unit 13 notifies the service determination time threshold processing unit 19 of the data volume of the uplink signal. The service determination time threshold processing unit 19 calculates the data volume of the uplink signal and the time threshold t th When the data volume of the uplink signal exceeds the time threshold t th In the case of the service information acquisition unit 13 monitoring the service at a predetermined monitoring period, the service determination time threshold processing unit 19 can compare the data volume of the uplink signal represented by the number of monitoring periods with the time threshold. Alternatively, the service determination time threshold processing unit 19 can convert the data volume of the uplink signal notified from the service information acquisition unit 13 into a comparison between the reception time of the uplink signal and the time threshold t th In addition, or, the service determination time threshold processing unit 19 can set the time threshold t th Transformed into the time threshold t th The amount of data that can be received within the same time is compared with the amount of data of the uplink signal notified from the traffic information acquisition unit 13 .

[0089] When receiving the instruction from the traffic determination time threshold processing unit 19, the bandwidth allocation amount calculation unit 17 allocates a fixed bandwidth to each terminal device 2. Figure 3 The process from step S105 onwards re-allocates bandwidth to each terminal device 2. By allocating bandwidth, the terminal station device 1b can allocate bandwidth corresponding to changes in the traffic volume of uplink signals of each terminal device 2, thereby reducing delays in transmission of uplink signals.

[0090] [Fourth embodiment]

[0091] In the fourth embodiment, unlike the second embodiment, the terminal station device receives an uplink signal sent through bandwidth allocation based on formula (4). The terminal station device of the first embodiment calculates the average value and standard deviation of the traffic volume based on the uplink traffic information, and uses the average value and standard deviation to estimate the bandwidth allocation amount. Therefore, the bandwidth allocated based on formula (4) is essentially unused bandwidth. Therefore, sending an uplink signal through bandwidth allocation based on formula (4) is consistent with the situation where a traffic volume that is significantly larger than the estimated result is generated. When the terminal station device of the fourth embodiment receives an uplink signal sent from the terminal device in the bandwidth allocation based on formula (4), it starts Figure 3 The processing from step S105 onwards is reset to fixed bandwidth allocation and re-estimated.

[0092] The terminal station device of the fourth embodiment can perform bandwidth allocation corresponding to changes in the traffic volume of uplink signals of each terminal device 2, similarly to the terminal station device 1b of the third embodiment, and can reduce delays in transmission of uplink signals.

[0093] [Fifth embodiment]

[0094] In the first to fourth embodiments, the terminal station device obtains the service of the uplink signal to estimate the service information, and performs bandwidth allocation based on the service information. The terminal station device of the fifth embodiment can obtain only the downlink service or both the uplink and downlink services instead of the uplink service, and use the obtained service information to perform the same processing as the first to fourth embodiments. When the service volume of the uplink signal is proportional to the service volume of the downlink signal, the terminal station device of the fifth embodiment can also perform bandwidth allocation to reduce delay in the same way as the terminal station devices of the first to fourth embodiments.

[0095] [Sixth embodiment]

[0096] When the relay transmission system accommodates multiple RRHs, the terminal station device estimates the traffic volume for each terminal device connected to the RRH and performs the above-mentioned first to fifth embodiments, thereby improving the bandwidth reduction effect. In addition, the beginning of the TTI varies depending on the RRH, so it can be handled by extracting it individually. The terminal station device can reduce the delay from the RRH (lower device) to the BBU (upper device) by performing bandwidth allocation synchronized with the TTI cycle of each RRH.

[0097] [Seventh embodiment]

[0098] The seventh embodiment is different from the first embodiment in the method of calculating the bandwidth allocation amount based on the average value and the bandwidth allocation amount based on the variance value.

[0099] Figure 7 1 is a block diagram showing the structure of a terminal station device 1c according to the seventh embodiment. Figure 7 In, with Figure 2 The same components of the terminal station device 1 according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Figure 7 The terminal station device 1c shown in the figure is different from the terminal station device 1 of the first embodiment in that a bandwidth allocation amount calculation unit 17c is provided instead of the bandwidth allocation amount calculation unit 17. Figure 8 The operation of the bandwidth allocation amount calculation unit 17c will be described with reference to the processing flow shown.

[0100] Figure 8 FIG. 2 is a process flow showing the operation of the terminal station device 1c. Figure 8 In, with Figure 3 The same processes as those performed by the terminal station device 1 of the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted. The terminal station device 1c performs the processes of step S105 to step S120 in the same manner as the terminal station device 1 of the first embodiment.

[0101] The bandwidth allocation amount calculation unit 17c performs the following processing of step S125 to step S150 for each bandwidth allocation period.

[0102] In the bandwidth allocation period, the bandwidth allocation amount calculation unit 17c reads the average value μ and standard deviation σ of the traffic volume of each terminal device 2 in the traffic period corresponding to the bandwidth allocation period of the target bandwidth allocation from the traffic volume estimation unit 15 (step S125). The bandwidth allocation amount calculation unit 17c allocates bandwidth B to each terminal device 2 in advance as shown in formula (5): avg （i） (Step S130c).

[0103] [Formula 5]

[0104] .

[0105] Different from the first embodiment, the bandwidth allocation amount calculation unit 17c performs bandwidth allocation based on the ratio of the average value μ of the traffic volume of the terminal device 2 to be allocated bandwidth divided by the sum of all the average values ​​of the traffic volume calculated for each terminal device 2. avg （i） It is an arbitrary bandwidth allocation amount for the i-th terminal device 2 , and may be the same for all the terminal devices 2 , or different for some or all of the terminal devices 2 .

[0106] The bandwidth allocation amount calculation unit 17 c calculates the bandwidth B based on the average value of the formula (5) for all the terminal devices 2. avgWhen allocating (step S135), bandwidth B based on the variance value of the standard deviation σ of the traffic volume is allocated to each terminal device 2 in sequence as shown in equation (6). var (Step S140c).

[0107] [Formula 6]

[0108] .

[0109] The bandwidth B based on the variance value var In the case of bandwidth allocation based on equation (5), the bandwidth allocation calculation unit 17c also performs bandwidth allocation based on the ratio of dividing the standard deviation σ of the traffic volume of the terminal device 2 to be allocated bandwidth by the sum of all standard deviations of the traffic volume calculated for each terminal device 2. Here, B' var （i） It is an arbitrary bandwidth allocation amount for the i-th terminal device 2 , and may be the same for all the terminal devices 2 , or different for some or all of the terminal devices 2 .

[0110] The bandwidth allocation amount calculation unit 17 c calculates the bandwidth B of all the terminal devices 2 based on the equation (6). var After the allocation (step S145), similarly to the first embodiment, the remaining bandwidth B calculated based on equation (4) is allocated to each terminal device 2. surplus (Step S150). In the remaining bandwidth B surplus In the allocation, a fixed bandwidth can be allocated equally to each terminal device 2, or the bandwidth allocation amount can be changed for each terminal device 2 according to the priority or the like. surplus In addition to being allocated to each terminal device 2, it can also be used as bandwidth for accommodating other services. surplus During this period, the terminal station device 1 c and each terminal device 2 can also perform a sleep operation. In addition, the order of allocating bandwidth to the terminal devices 2 using equations (4) to (6) may be different.

[0111] The seventh embodiment can also be used in conjunction with the first embodiment. That is, the bandwidth allocation based on the average value may be allocated in accordance with the allocation of the first embodiment, and the bandwidth allocation based on the standard deviation may be allocated in accordance with the allocation of the seventh embodiment. Or, conversely, the bandwidth allocation based on the average value may be allocated in accordance with the allocation of the seventh embodiment, and the bandwidth allocation based on the standard deviation may be allocated in accordance with the allocation of the first embodiment. The terminal station device can also implement bandwidth allocation in such a combination. The terminal station device 1c sequentially performs two allocations, namely, a bandwidth allocation based on the average value μ of the traffic volume calculated for each terminal device 2 and a bandwidth allocation based on the standard deviation σ of the traffic volume calculated for each terminal device 2. Through such an allocation, as in the first embodiment, the standby time (communication delay) before each terminal device 2 obtains a communication opportunity can be reduced.

[0112] [Eighth embodiment]

[0113] In the eighth embodiment, the method of calculating the bandwidth allocation amount is different from that in the first to seventh embodiments. Fig. 9 1 is a functional block diagram showing the structure of a terminal station device 1d according to the eighth embodiment. Fig. 9 In, yes Figure 2 The same components of the terminal station device 1 according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Fig. 9 The terminal station device 1d shown in the figure is different from the terminal station device 1 of the first embodiment in that a bandwidth allocation amount calculation unit 17d is provided instead of the bandwidth allocation amount calculation unit 17. Fig.10 The operation of the bandwidth allocation amount calculation unit 17d will be described with reference to the processing flow shown.

[0114] Fig.10 FIG. 2 is a process flow showing the operation of the terminal station device 1d. Fig.10 In, with Figure 3 The same processes as those performed by the terminal station device 1 of the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted. The terminal station device 1d performs the processes of step S105 to step S115 in the same manner as the terminal station device 1.

[0115] The traffic volume estimation unit 15 calculates the average value μ of the traffic volume for each terminal device 2 based on the traffic information extracted by the traffic information extraction unit 14 (step S220 ). The traffic volume estimation unit 15 may calculate the average value μ for each terminal device 2 using the traffic volume in a predetermined number of recent traffic cycles.

[0116] The bandwidth allocation amount calculation unit 17d performs the following processing of step S225 to step S260 for each bandwidth allocation period.

[0117] The bandwidth allocation amount calculation unit 17d reads the average value μ of the traffic volume of each terminal device 2 from the traffic volume estimation unit 15.i (Step S225 ) The bandwidth allocation amount calculation unit 17 d calculates the average value μ of each terminal device 2 as shown in Formula (7). i The average value μ of terminal device 2 i The bandwidth B is the ratio of the sum of i As the bandwidth allocation amount to each terminal device 2 (step S230), the bandwidth allocation amount calculation unit 17d calculates the bandwidth B allocated to each terminal device 2 using the total bandwidth available in the DBA period as shown in equation (7). i The average value μ of each terminal device 2 is i With the average value μ i The ratio of the sum of all To calculate the bandwidth B i When calculating the bandwidth allocation amount in step S230, the remaining bandwidth B surplus Initialized to zero.

[0118] [Formula 7]

[0119] .

[0120] The bandwidth allocation amount calculation unit 17d performs the processing of steps S235 to S255 for each of the terminal devices 2 connected to the terminal station device 1d.

[0121] The bandwidth allocation amount calculation unit 17d determines the bandwidth B allocated to the i-th terminal device 2 among all the terminal devices 2. i Is it greater than the predetermined threshold value Th upper Large (step S235). i Ratio threshold Th upper If the bandwidth B is greater than the bandwidth B of the ith terminal device 2 (step S235, yes), the bandwidth allocation amount calculation unit 17d allocates the bandwidth B to the ith terminal device 2. i Change to threshold Th upper , and the bandwidth of the difference (B i -Th upper ) is added to the remaining bandwidth B surplus (Step S240).

[0122] In bandwidth B i is the threshold value Th upper In the following case (step S235, No), the bandwidth allocation amount calculation unit 17d determines that the bandwidth B i Is it greater than the predetermined threshold value Th lower Great (step S245). Threshold Th lower Ratio threshold Th upper Small. In bandwidth B i Ratio threshold Th lowerIf the bandwidth B is greater than the bandwidth B of the i-th terminal device 2 (step S245, yes), the bandwidth allocation amount calculation unit 17d allocates the bandwidth B to the i-th terminal device 2. i Change to threshold Th lower , and the bandwidth of the difference (B i -Th lower ) is added to the remaining bandwidth B surplus (Step S250).

[0123] In bandwidth B i is the threshold value Th lower In the following case (step S245, No), the bandwidth allocation amount calculation unit 17d makes the bandwidth B i is the threshold value Th lower The number N of the following terminal devices 2 onu Increase by 1 and set the bandwidth B i Add to the remaining bandwidth B surplus (Step S255).

[0124] The bandwidth allocation amount calculation unit 17d allocates the bandwidth B i is the threshold value Th lower The following N onu The bandwidth B of each terminal device 2 i Change to equally allocate the remaining bandwidth B surplus Bandwidth B i =(B surplus / N onu ) (Step S260). That is, the bandwidth allocation amount calculation unit 17d evenly allocates the bandwidth exceeding the threshold value Th upper Or threshold Th lower Bandwidth B i The remaining bandwidth B is the unallocated bandwidth other than the bandwidth allocated to the terminal device 2. surplus The bandwidth allocation amount calculation unit 17d calculates the bandwidth B corresponding to each terminal device 2. i The bandwidth allocation amounts are allocated in order from the beginning of the bandwidth allocation period.

[0125] After performing a temporary allocation based on the average value μ of the traffic volume of each terminal device 2, the terminal station device 1d allocates the traffic volume based on the two threshold values ​​Th upper ,Th lower The bandwidth allocated to each terminal device 2 is adjusted. upper The allocated bandwidth is suppressed to the threshold Th upper , thereby being able to suppress the allocation of bandwidth from being biased toward some of the terminal devices 2. Therefore, the terminal station device 1d can reduce the waiting time (communication delay) until each terminal device 2 obtains a communication opportunity.

[0126] Although the full bandwidth B that can be used in step S230 is describedall The average value μ is proportionally distributed to each terminal device 2. However, the average value μ distributed to each terminal device 2 may also be used. i Bandwidth B i The bandwidth allocation amount calculation unit 17d may also use one or more than three thresholds to adjust the allocated bandwidth. For example, when one threshold is used to adjust the bandwidth allocation, the bandwidth allocation amount calculation unit 17d may use one or more than three thresholds to adjust the allocated bandwidth. i is the threshold value Th upper In the following case (step S235, No), the process of step S255 is performed.

[0127] [Ninth embodiment]

[0128] In the eighth embodiment, the terminal station device 1d acquires the service of the uplink signal to estimate the service information, and performs bandwidth allocation based on the service information. The terminal station device of the ninth embodiment can acquire only the downlink service or both the uplink and downlink services instead of the uplink service, and use the acquired service information to perform the same processing as the eighth embodiment. When the service volume of the uplink signal and the service volume of the downlink signal are in a proportional relationship, the terminal station device of the ninth embodiment can also perform bandwidth allocation to reduce delay in the same manner as the terminal station device of the eighth embodiment.

[0129] [Tenth embodiment]

[0130] When the relay transmission system accommodates multiple RRHs, the terminal station device 1d according to the eighth embodiment estimates the traffic volume for each terminal device 2 connected to the RRH and allocates bandwidth to each terminal device 2, thereby improving the bandwidth reduction effect. In addition, the beginning of the TTI is different from the RRH, so it can be handled by extracting it individually. The terminal station device can reduce the delay from the RRH (lower device) to the BBU (upper device) by performing bandwidth allocation synchronized with the TTI cycle of each RRH.

[0131] According to the above-described embodiment, the bandwidth allocation device includes a service information acquisition unit, a service head position detection unit, a service information extraction unit, a service volume estimation unit, and a bandwidth allocation unit. The bandwidth allocation device is, for example, a terminal station device 1, 1a, 1b, 1c, but may also be an external device connected to the terminal station device, and the bandwidth allocation device may also be implemented by the terminal station device and the external device.

[0132] The traffic information acquisition unit acquires traffic information showing the traffic volume of each lower device communicating via the terminal device for each lower device connected to the terminal device. The traffic head position detection unit detects the head timing of the burst traffic based on the traffic information. The traffic information extraction unit extracts the traffic volume information of each of the plurality of traffic allocation periods from the traffic information collected for each lower device. The traffic volume estimation unit calculates the average value and standard deviation of the traffic volume in the traffic allocation period for each lower device based on the traffic volume information extracted by the traffic information extraction unit.

[0133] The bandwidth allocation unit is, for example, a bandwidth allocation amount calculation unit 17. The bandwidth allocation unit uses the head timing detected by the service head position detection unit as the head timing of the bandwidth allocation period, and allocates the first bandwidth, which is the allocated bandwidth based on the average value of the service volume, to the terminal device from the head of the bandwidth allocation period. The first bandwidth is calculated, for example, by formula (2). After the allocation of the first bandwidth to all terminal devices is completed, the bandwidth allocation unit allocates the second bandwidth, which is the allocated bandwidth based on the standard deviation of the service volume, to the terminal device. The second bandwidth is calculated, for example, by formula (3). The bandwidth allocation unit allocates the remaining bandwidth, which is the bandwidth that can be allocated in the bandwidth allocation period excluding the first bandwidth and the second bandwidth that have been allocated, to each terminal device within the remaining bandwidth allocation period, which is the period from the end of the allocation of the second bandwidth to all terminal devices to the end of the bandwidth allocation period.

[0134] Furthermore, the bandwidth allocation unit may calculate the first bandwidth according to the ratio of the average value of the traffic volume in the terminal device to which the bandwidth is allocated to be allocated to the total average value of the traffic volume in all the terminal devices as shown in formula (5). Furthermore, the bandwidth allocation unit may calculate the second bandwidth according to the ratio of the standard deviation of the traffic volume in the terminal device to which the bandwidth is allocated to be allocated to the total standard deviation of the traffic volume in all the terminal devices as shown in formula (6).

[0135] The bandwidth allocation device may further include a newly connected terminal device authentication unit that sets an authentication period for detecting a newly connected terminal device in the remaining bandwidth allocation period. The bandwidth allocation unit does not allocate bandwidth to the terminal device during the authentication period notified from the newly connected terminal device authentication unit.

[0136] In addition, the bandwidth allocation device may also include a traffic excess determination processing unit. The traffic excess determination processing unit is, for example, a traffic determination time threshold processing unit 19. When the traffic volume of an uplink signal sent from a terminal device using the second bandwidth exceeds a threshold, the traffic excess determination processing unit determines that the traffic volume is abnormally excessive, and instructs the bandwidth allocation unit to redo bandwidth allocation. Alternatively, when an uplink signal using the remaining bandwidth is sent from a terminal device, the traffic volume is determined to be abnormally excessive, and the bandwidth allocation unit is instructed to redo bandwidth allocation.

[0137] According to the above-described embodiment, when allocating bandwidth to each terminal device within the bandwidth allocation cycle, the allocation based on the average value and the allocation based on the standard deviation are separated. By preliminarily allocating bandwidth based on the average value, the waiting time of each terminal station device can be reduced.

[0138] The functions of the terminal station devices 1, 1a, 1b, 1c, and 1d in the above-mentioned embodiments can be realized by a computer. In this case, a program for realizing the function can be recorded in a computer-readable recording medium, and the program recorded in the recording medium can be read into the computer system and executed to realize it. In addition, the "computer system" mentioned here includes hardware such as OS and peripheral devices. In addition, "computer-readable recording medium" refers to removable media such as floppy disks, optical magnetic disks, ROMs, CD-ROMs, and storage devices such as hard disks built into the computer system. Furthermore, "computer-readable recording medium" can include a medium that dynamically retains the program for a short period of time, such as a communication line in the case of sending a program via a network such as the Internet or a communication line such as a telephone line, and a medium that retains the program for a certain period of time, such as a volatile memory inside a computer system that becomes a server or client in this case. In addition, the above-mentioned program can be a program for realizing a part of the above-mentioned function, and can be a program that can realize the above-mentioned function by combining with a program already recorded in the computer system.

[0139] As mentioned above, although the embodiment of the present invention is described in detail with reference to the drawings, the specific structure is not limited to this embodiment, and includes designs and the like within the scope that does not depart from the gist of the present invention.

[0140] Industrial Applicability

[0141] The present invention can be applied to a system that communicates by time division multiple access.

[0142] Description of Reference Numerals

[0143] 1, 1a, 1b, 1c, 1d…Terminal station device

[0144] 2…Terminal device

[0145] 3…Optical separator

[0146] 5…upper device

[0147] 6…Lower device

[0148] 8…Access to network system

[0149] 41, 42…Optical fiber

[0150] 11…Upper level transceiver function unit

[0151] 12…Lower transceiver function unit

[0152] 13…Business Information Acquisition Department

[0153] 14…Business Information Extraction Department

[0154] 15…Business Volume Estimation Department

[0155] 16…Business front position detection department

[0156] 17, 17c, 17d ... bandwidth allocation amount calculation unit

[0157] 18…Newly connected terminal device authentication department

[0158] 19…Business determination time threshold processing unit.

Claims

1. A relay transmission system for relaying communications in a communication system that performs wireless communications in a TDD manner, wherein: A bandwidth allocation device is provided, wherein the bandwidth allocation device comprises: A traffic information acquisition unit that acquires traffic information indicating a traffic volume of communications performed by a lower device via a terminal device; A traffic estimation unit, which calculates the remaining uplink bandwidth according to the traffic information; as well as The newly connected terminal device authentication unit sets an activation window in the uplink remaining bandwidth, wherein the activation window is a period during which the newly connected terminal device can send a signal for requesting authentication to the terminal station device.

2. A relay transmission method is a relay transmission method performed by a bandwidth allocation device in a relay transmission system for relaying communications in a communication system for wireless communications in a TDD manner, wherein: Acquiring business information, the business information indicating the business volume of communication performed by the lower device via the terminal device; Calculating the remaining uplink bandwidth according to the service information; as well as An activation window is set in the uplink remaining bandwidth. The activation window is a period during which a newly connected terminal device can send a signal for requesting authentication to a terminal station device.

Images