JP2018133663A - Radio communication system and base station device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication system capable of preventing or reducing the occurrence of delay to a time taken to transmit data to a base station device due to a time taken until the base station device receives a BSR (Buffer Status Report).SOLUTION: A base station device includes: a pseudo report generation unit 216 for generating a pseudo buffer state report indicating a value obtained by estimating an amount of data retained in a buffer; and a time determination unit 215 for determining generation time when the pseudo report generation unit generates a pseudo buffer state report according to time when the data is predicted to be stored in the buffer. The pseudo report generation unit generates a pseudo buffer state report at the generation time. An allocation unit 218 allocates a communication opportunity to a terminal according to an amount of data indicated by a pseudo buffer state report if the pseudo report generation unit has generated the pseudo buffer state report.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a radio communication system in which a base station apparatus allocates an uplink communication opportunity according to the amount of data stored in a buffer of the terminal to the terminal, and a base station apparatus used in the radio communication system.

  In recent years, with the advent of wide-area wireless communication standards such as LTE (Long Term Evolution), high-speed wireless communication services have been provided. In LTE, a terminal which is a user-side radio communication device is assigned a communication opportunity from a base station device which is a radio communication device used in a radio base station, and communicates with the base station device according to the assigned communication opportunity. . Note that the communication opportunity indicates conditions such as a frequency band and time in which the terminal and the base station apparatus can communicate, and a modulation scheme, and in the case of LTE, the allocated communication opportunity is indicated by a frequency band and time in which communication is possible. . The terminal communicates with the base station apparatus in the indicated frequency band at the time indicated by the assigned communication opportunity.

  A case of uplink communication in which data is transmitted from the terminal to the base station apparatus will be described. When data to be transmitted to the base station apparatus is stored in the buffer, the terminal transmits a scheduling request (hereinafter referred to as SR: Scheduling Request) requesting allocation of a communication opportunity to the base station apparatus.

  When receiving the SR, the base station apparatus allocates a communication opportunity and transmits a signal instructing transmission according to the allocated communication opportunity to the terminal. The terminal calculates the amount of data that can be transmitted at the communication opportunity instructed to the base station apparatus, and transmits a buffer status report (hereinafter, BSR: Buffer Status Report) indicating the amount of data stored in the buffer, If possible, send the data stored in the buffer. When data is transmitted, the data amount indicated by the buffer status report is the untransmitted data amount stored in the buffer.

  When receiving the BSR, the base station apparatus allocates a communication opportunity according to the data amount indicated by the BSR so that the data amount can be transmitted, and sends a signal instructing the terminal to perform transmission according to the allocated communication opportunity. Send. The terminal transmits the data stored in the buffer to the base station apparatus according to the communication opportunity instructed by the base station apparatus.

  Thereby, even when there are a plurality of terminals having data to be transmitted to one base station apparatus, communication opportunities can be allocated so that data can be efficiently transmitted according to the data amount of each terminal. It becomes possible.

  Note that, as disclosed in Patent Document 1, the terminal may also transmit a BSR when receiving a buffer status report trigger instruction transmitted by the base station.

JP, 2014-138310, A

  On the other hand, there is a movement to use such wide-area wireless communication standards in various devices including devices other than portable information terminals such as smartphones, for example, vehicles, machine tools, vending machines, and the like. This is because by adding a wireless communication function, it is possible to increase the added value of the product, such as enhancing after-sales service and improving business efficiency.

  For example, when a vehicle is provided with a wireless communication function, it is conceivable to provide information services such as traffic information and navigation in real time, or to acquire the position and speed from each vehicle and use it for accident prevention.

  As described above, as the devices having the wireless communication function and the purpose of use of the wireless communication function are diversified, an increase in application software that requires a wireless communication function with little delay is expected. For example, in a vehicle, a wireless communication function with little delay is required when accidents are prevented by acquiring a position and speed from each vehicle.

  Here, the base station apparatus according to the LTE standard assigns a communication opportunity to the terminal according to the BSR transmitted by the terminal. Therefore, in order to transmit the data stored in the buffer, a BSR indicating that the data is stored in the buffer is transmitted, and the base station apparatus that has received the BSR allocates a communication opportunity according to the amount of data. Need to wait.

  That is, the time from when the data is stored in the buffer until it is transmitted to the base station apparatus changes according to the time until the base station receives the BSR. For this reason, when a delay occurs in the time until the BSR is received, for example, when the base station cannot receive the BSR, the time until the data is transmitted is also delayed accordingly. This delay may be a problem when transmitting data that requires communication with less delay.

  The present invention has been made based on this situation, and the time until the base station apparatus receives the BSR and the time from when the data is stored in the buffer until it is transmitted to the base station apparatus. An object of the present invention is to provide a radio communication system capable of suppressing the occurrence of delay and a base station apparatus used in the radio communication system.

  The above object is achieved by a combination of the features described in the independent claims, and the subclaims define further advantageous embodiments of the invention. Reference numerals in parentheses described in the claims indicate a correspondence relationship with specific means described in the embodiments described later as one aspect, and do not limit the technical scope of the present invention. .

  To achieve the above object, the present invention provides a base station device (200) that is a wireless communication device used in a wireless base station, and a terminal that is a wireless communication device that wirelessly transmits data stored in a buffer to the base station device. (100), and the base station apparatus determines the amount of data stored and held in the buffer from the reception processing unit (211) that receives the signal transmitted by the terminal and the signal received by the reception processing unit. A report acquisition unit (213) that acquires a buffer status report to be indicated, and an allocation unit (218) that allocates a communication opportunity to the terminal according to the amount of data indicated by the buffer status report received by the report acquisition unit. A wireless communication system that transmits data to a base station apparatus according to a communication opportunity assigned by the base station apparatus, wherein the base station apparatus uses a value obtained by estimating an amount of data held in a buffer. A pseudo report generator (216) that generates a pseudo buffer status report, and a time determination for determining a generation time at which the pseudo report generator generates a pseudo buffer status report according to a time when data is predicted to be stored in the buffer. The pseudo report generation unit generates a pseudo buffer status report at the generation time, and the allocation unit indicates the pseudo buffer status report even when the pseudo report generation unit generates the pseudo buffer status report. Communication opportunities are assigned to terminals according to the amount of data.

  According to the above configuration, the pseudo report generation unit obtains a value obtained by estimating the amount of data stored in the buffer at the generation time determined by the time determination unit according to the time when the data is predicted to be stored in the buffer. Generate as a pseudo-buffer status report. The allocation unit allocates communication opportunities to the terminals according to the amount of data indicated by the pseudo buffer status report. Therefore, communication opportunities are allocated according to the amount of data estimated to be stored at a time determined according to the time when the data is predicted to be stored in the buffer.

  Thereby, when data is stored in the buffer, the base station apparatus can allocate a communication opportunity to transmit data to the terminal regardless of whether or not the BSR indicating that the data is stored is received. It becomes. Therefore, it is possible to suppress the time from when the data is stored in the buffer until the data is transmitted according to the time delay until the base station apparatus receives the BSR.

  Moreover, the invention which concerns on the base station apparatus for achieving the said objective is an invention which concerns on the base station apparatus used for the radio | wireless communications system of this invention. That is, the invention according to the base station apparatus for achieving the above object includes a reception processing unit (211) that receives a signal transmitted from a terminal that is a wireless communication apparatus that wirelessly transmits data stored in a buffer, and a reception process. A report acquisition unit (213) that acquires a buffer status report indicating the amount of data stored and held in the buffer from the signal received by the unit, and according to the amount of data indicated by the buffer status report received by the report acquisition unit An allocating unit (218) for allocating a communication opportunity to a terminal, and a base station device that is a radio communication device used in the radio base station, the pseudo buffer indicating a value obtained by estimating an amount of data held in the buffer A pseudo report generator (216) that generates a status report and a pseudo report generator according to a time at which low-delay data is predicted to be stored in the buffer. A time determination unit (215) that determines a generation time for generating a status report, the pseudo report generation unit generates a pseudo buffer status report at the generation time, and the allocation unit generates a pseudo buffer status report by the pseudo report generation unit; Even when it is generated, communication opportunities are assigned to the terminals according to the amount of data indicated by the pseudo buffer status report.

1 is a diagram showing an outline of a wireless communication system 1 according to an embodiment. 2 is a diagram showing a configuration of a terminal 100. FIG. FIG. 3 is a diagram showing a configuration of a base station apparatus 200. 3 is a flowchart showing the operation of the terminal 100. 4 is a flowchart showing the operation of the base station apparatus 200. It is a figure which shows the communication procedure of the terminal 100 and the base station apparatus 200. FIG. It is a figure which shows the communication procedure of the terminal 100 and the base station apparatus 200. FIG. It is a figure explaining the data amount which the pseudo BSR is generated, and the pseudo BSR. It is a figure explaining the data amount which the pseudo BSR is generated, and the pseudo BSR.

  Hereinafter, a wireless communication system 1 as an embodiment of the present invention will be described with reference to the drawings. Before entering the configuration and detailed description of the wireless communication system 1, the schematic configuration of the wireless communication system 1 will be described with reference to FIG. The wireless communication system 1 is a system that provides wireless communication compliant with LTE as a wide area wireless communication standard.

  The radio communication system 1 includes a terminal 100 that is a user-side radio communication device and a base station device 200 that is a radio communication device used in a radio base station. In FIG. 1, one terminal 100 and one base station apparatus 200 are shown, but there may actually be a plurality of terminals. Base station apparatus 200 allocates a communication opportunity to each of terminals 100 located in the communication area, and communicates with terminal 100 at the allocated communication opportunity.

  The terminal 100 may be a mobile communication terminal such as a smartphone or a tablet terminal, or may be a communication device provided in a vehicle or a vending machine. Hereinafter, communication between terminal 100 provided in a certain vehicle and base station apparatus 200 will be described as an example. Hereinafter, a vehicle equipped with the terminal 100 is called a host vehicle.

  In the following description, a method of allocating a communication opportunity in uplink communication in which terminal 100 transmits data to base station apparatus 200 among communications between terminal 100 and base station apparatus 200 will be described. Therefore, the communication opportunity in the following description refers to an uplink communication opportunity indicating a situation in which the terminal 100 can transmit data to the base station apparatus 200. Portions that are not described in this embodiment, such as downlink communication in which the base station apparatus 200 transmits data to the terminal 100, are performed by a method defined by the LTE standard.

[Configuration of terminal 100]
The configuration of the terminal 100 will be described with reference to FIG. The terminal 100 includes a terminal communication unit 101 and a terminal control unit 102. The terminal communication unit 101 includes an antenna that can transmit and receive radio waves in a frequency band used in LTE, and a transceiver that performs transmission processing such as encoding and modulation and reception processing such as demodulation and decoding in accordance with LTE communication standards. A communication module provided. The terminal communication unit 101 transmits a transmission wave corresponding to the signal input from the terminal control unit 102 by performing a transmission process from the antenna, and performs a reception process to transmit a signal corresponding to the reception wave received by the antenna. Output to the control unit 102.

  The terminal control unit 102 is a computer that includes a CPU, a ROM, a RAM, and the like. The CPU exhibits a predetermined function by executing a program stored in a non-transitory tangible storage medium while using the temporary storage function of the RAM. The non-transitional tangible recording medium can be realized using a semiconductor storage device such as a ROM or a RAM, or a magnetic recording medium such as a magnetic disk. When the CPU executes the program, the terminal control unit 102 functions as the communication control unit 110 and the application unit 120.

  The application unit 120 is a general term for various functions that are exhibited by executing various application programs stored in a ROM included in the terminal control unit 102. In the present embodiment, as one of various functions, for example, in order to support driving operations such as acceleration / deceleration and lane change, driving support information such as the position and speed of vehicles around the own vehicle is provided to the base station apparatus 200. A support information acquisition function that sequentially acquires information by communicating with a predetermined server. As another example of the function, a road condition acquisition function is provided which periodically acquires road conditions such as traffic restrictions and traffic jams by communicating with a predetermined server.

  Various functions included in the application unit 120 generate data to be transmitted to the base station apparatus 200 (hereinafter, user data). For example, the support information acquisition function includes predetermined data for generating driving support information for surrounding vehicles, such as the position, speed, and traveling direction of the host vehicle, and driving support in order to periodically acquire driving support information. User data composed of data requesting transmission of information is periodically generated. These user data are transmitted to the base station apparatus 200 and transmitted to a server as a transmission destination determined by the function that generated the user data via a public line network such as the Internet. The user data includes a header that stores information such as a transmission destination used for transmission of the user data.

  The communication control unit 110 includes functions as a buffer 111, a request transmission unit 113, a communication opportunity reception unit 112, a report transmission unit 114, and a data transmission unit 115. The buffer 111 is a function of storing user data generated by the application unit 120 and temporarily holding the user data until the user data is transmitted to the base station apparatus 200. For example, the user data is stored in a RAM included in the terminal control unit 102. It is realized by doing. The buffer 111 also has a function of monitoring the amount of user data held and information stored in the headers of those user data.

  The user data stored in the buffer 111 has a greater need to suppress communication delay than other user data, and low delay data in which a predetermined amount is stored in a predetermined cycle. Is included.

  Here, the driving support information has a large change with the passage of time as compared with road conditions and the like, and since the reliability of the information is likely to be lowered due to the delay, the necessity of suppressing the communication delay is great. Further, the user data generated by the support information acquisition function is generated at a predetermined cycle and is stored in the buffer 111 in order to periodically acquire the driving support information. Furthermore, since the content of user data generated by the support information acquisition function is constant between predetermined data for generating driving support information to surrounding vehicles and data requesting transmission of driving support information, The amount of data is constant. That is, a predetermined amount of user data generated by the support information acquisition function is stored in the buffer 111 at a predetermined cycle. Therefore, the user data generated by the support information acquisition function corresponds to the low delay data in this embodiment.

  A predetermined period in which the low-delay data generated by the support information acquisition function is stored in the buffer is defined as a period T, and a predetermined amount stored in each period T is defined as a data amount D. Further, user data generated by other functions is assumed to be normal data. In the present embodiment, whether the user data is low-delay data or normal data can be distinguished by storing a data type indicating whether the user data is low-delay data or normal data in the header.

  The communication opportunity receiving unit 112 acquires the communication opportunity that the base station apparatus 200 assigns and transmits and the terminal communication unit 101 receives. This communication opportunity indicates a situation in which the terminal 100 can transmit user data and a buffer status report (hereinafter referred to as “BSR”).

  When the user data is stored in the buffer 111, the request transmission unit 113, when the communication opportunity reception unit 112 has not acquired the communication opportunity, and when the time indicated by the acquired communication opportunity has expired, the base station Request device 200 to assign a communication opportunity. Specifically, the terminal communication unit 101 is caused to transmit a scheduling request (hereinafter referred to as SR: Scheduling Request) for requesting the base station apparatus 200 to allocate a communication opportunity when a condition defined by the LTE standard is satisfied. The situation that satisfies the condition for transmitting the SR is, for example, a situation in which user data is stored in the empty buffer 111, or a situation in which a predetermined time has passed without being assigned a transmission opportunity even though an assignment request is made. .

  The report transmission unit 114 causes the terminal communication unit 101 to transmit a BSR indicating the amount of user data held in the buffer 111 to the base station apparatus 200. However, when the base station apparatus 200 allocates a communication opportunity that can transmit not only BSR but also user data to the transmitted SR, the report transmission unit 114 transmits not only the BSR but also the amount that can be transmitted. User data is also sent. In this case, the data amount indicated by the BSR is the amount of user data that cannot be transmitted at the transmission opportunity and remains held in the buffer 111.

  Specifically, the report transmission unit 114 compares the amount of user data held in the buffer 111 with the amount of user data that can be transmitted at the communication opportunity acquired by the communication opportunity reception unit 112. As a result, the amount of user data that is not transmitted to the base station apparatus 200 at that communication opportunity but remains held in the buffer 111 is obtained. Thereafter, the terminal communication unit 101 causes the base station apparatus 200 to transmit a BSR indicating the amount of user data held in the buffer 111 according to the communication opportunity acquired by the communication opportunity receiving unit 112. As a result, the base station apparatus 200 is requested to allocate a communication opportunity that allows transmission of user data held in the buffer 111. Note that the amount of user data that can be transmitted in the communication opportunity acquired by the communication opportunity receiving unit 112 can be calculated based on the transmittable time and frequency band included in the communication opportunity.

  The data transmission unit 115 causes the terminal communication unit 101 to transmit the user data held in the buffer 111 to the base station apparatus 200 in accordance with the communication opportunity acquired by the communication opportunity reception unit 112. However, when the report transmission unit 114 transmits the BSR, the BSR is transmitted with priority over the user data. Further, when low delay data and normal data are stored in the buffer 111, the low delay data is preferentially transmitted.

  With the above function, the communication control unit 110 requests assignment of a communication opportunity so that the user data generated by the application unit 120 can be transmitted, and transmits user data at the assigned communication opportunity.

[Configuration of base station apparatus 200]
The configuration of base station apparatus 200 will be described using FIG. Base station apparatus 200 includes base station communication section 201 and base station control section 202. The base station communication unit 201 includes an antenna that can transmit and receive radio waves in a frequency band used in LTE, a transceiver that performs transmission processing such as encoding and modulation, and reception processing such as demodulation and decoding in accordance with LTE communication standards. It is a communication module provided with. The base station communication unit 201 transmits a transmission wave corresponding to the signal input from the base station control unit 202 by performing transmission processing, and a signal corresponding to the reception wave received by the antenna by performing reception processing. Is output to the base station control unit 202.

  The base station control unit 202 is configured as a normal computer including a CPU, a RAM, a ROM, an I / O, and a bus line that connects these configurations. The CPU executes the program stored in the non-transitional tangible recording medium while using the temporary storage function of the RAM. Thereby, the base station control unit 202 receives the reception processing unit 211, the request acquisition unit 212, the report acquisition unit 213, the data determination unit 2141, the time determination unit 215, the pseudo report generation unit 216, and the transmission stop determination. The function as the part 217 and the allocation part 218 is exhibited. Further, the ROM provided in the base station control unit 202 stores in advance a data amount D and a period T corresponding to the type of the terminal 100.

  The reception processing unit 211 acquires a signal received by the base station communication unit 201. If user data is included in the acquired signal, the user data is stored in the header of user data through a public line network (not shown). To the destination.

  The request acquisition unit 212 acquires the SR included in the signal acquired by the reception processing unit 211 and inputs the SR to the allocation unit 218, so that at least a BSR can be transmitted to the terminal 100 that transmitted the SR. The allocation unit 218 is requested to allocate a communication opportunity.

  The report acquisition unit 213 acquires the BSR included in the signal acquired by the reception processing unit 211, and allocates a communication opportunity that can transmit the data amount indicated by the BSR to the terminal 100 that has transmitted the BSR. Request to 218.

  The terminal determination unit 214 determines whether or not the terminal 100 with which the base station apparatus 200 is communicating is a low-delay terminal that transmits low-delay data. The pseudo report generation unit 216 generates a pseudo buffer status report (hereinafter, pseudo BSR). The terminal determination unit 214 of this embodiment includes a data determination unit 2141. When the reception processing unit 211 acquires user data, the data determination unit 2141 determines whether the user data is low-delay data or normal data. Whether the data is low delay data or normal data may be determined using the data type stored in the header. When the data determination unit 2141 determines that the user data is low delay data, the terminal determination unit 214 determines that the terminal 100 that has transmitted the user data is a low delay terminal.

  The time determination unit 215 determines the generation time at which the pseudo report generation unit 216 generates the pseudo BSR according to the time when low delay data is predicted to be stored in the buffer 111 of the terminal 100. In the present embodiment, the time determination unit 215 becomes a generation time every period T from the reference time T0 that is the time when the reception processing unit 211 determines that the signal received by the base station communication unit 201 is SR. The generation time is determined as follows. That is, the generation time is determined so that the n-th generation time Tn is Tn = T0 + n × T. Note that the period T is determined in advance according to the type of the terminal 100 and is stored in the ROM of the base station control unit 202.

  Assuming that the reference time T0 is the time when the low delay data is stored in the buffer 111, the generation time determined by this is the time when the low delay data is predicted to be stored in the subsequent buffer 111 It becomes. That is, in the present embodiment, SR is transmitted when low-delay data is stored in the buffer 111, and the low-delay data is stored on the assumption that the reference time T0 matches the time when the low-delay data is stored. Then, the predicted time is determined as the generation time.

  The pseudo report generation unit 216 generates a pseudo BSR indicating a value obtained by estimating the amount of low delay data stored in the buffer 111 at the generation time determined by the time determination unit 215. Accordingly, a communication opportunity for transmitting low-delay data is assigned to the terminal 100 regardless of whether the BSR is received. In the present embodiment, a pseudo BSR indicating the data amount D stored in the ROM included in the base station control unit 202 is generated, and the allocation unit 218 is requested to allocate a communication opportunity according to the generated pseudo BSR.

  The transmission stop determination unit 217 determines whether or not the time from the most recent time when the data determination unit 2141 determines that the received user data is low-delay data is equal to or greater than a transmission stop threshold that the transmission is considered to be stopped. To do. When it is determined that the transmission stop threshold is exceeded, it can be considered that, for example, the terminal 100 is out of the communication area of the base station apparatus 200 and transmission of low-delay data from the terminal 100 is stopped. Accordingly, in this case, it is not necessary to allocate a communication opportunity for transmitting low-delay data, and the pseudo report generation unit 216 stops generating the pseudo BSR. The transmission stop threshold may be determined by adding the maximum predicted value of the delay from when the low delay data is stored in the buffer 111 to when it is stored in the buffer 111 until it is transmitted. It may be doubled.

  The allocation unit 218 allocates a communication opportunity to the terminal 100 in accordance with requests from the request acquisition unit 212, the report acquisition unit 213, and the pseudo report generation unit 216, and assigns the allocated communication opportunity to the base station communication unit 201 to the terminal 100. Send it. Specifically, when SR is input from the request acquisition unit 212, at least a communication opportunity that can be transmitted by the BSR is assigned. When the BSR and the pseudo BSR are input from the report acquisition unit 213 and the pseudo report generation unit 216, a communication opportunity capable of transmitting the data amount indicated by the BSR and the pseudo BSR is assigned. This assignment may be performed in multiple steps in consideration of the radio wave propagation environment between the terminal 100 and the base station apparatus 200 and the generation status of requests from other terminals. That is, the data amount may be transmitted by combining the communication opportunities assigned by the assignment over multiple times, and it is necessary to assign the communication opportunity so that all the data amount can be transmitted by one assignment. Absent.

  Further, when both the BSR and the pseudo BSR are input from both the report acquisition unit 213 and the pseudo report generation unit 216, the assignment according to the pseudo BSR is not performed, and only the allocation according to the BSR is performed.

  When a communication opportunity is allocated to terminal 100, allocation section 218 requests base station communication section 201 to transmit a signal to terminal 100 to instruct the terminal 100 to transmit a signal at the allocated communication opportunity.

[Operation of terminal 100]
The operation of the terminal 100 will be described along the flowchart of FIG. The terminal control unit 102 exhibits the function as the application control unit 120 and also exhibits the function as the communication control unit 110 by sequentially executing the processing shown in FIG. 4 from S1.

  In S <b> 1, it is determined whether user data generated by the application unit 120 is input and held in the buffer 111 in order to wait for transmission to the base station apparatus 200. If it is determined that it is held, the process proceeds to S2, and if it is determined that it is not held, the process of S1 is performed again. S <b> 1 is processing as the buffer 111.

  In S <b> 2, the terminal communication unit 101 determines whether a communication opportunity transmitted from the base station apparatus 200 has been received. If it is determined that it has been received, the process proceeds to S4. If it is determined that it has not been received, the process proceeds to S3. However, even if a communication opportunity has been received, it is determined that the communication opportunity has not been received if all the transmittable periods indicated by the received communication opportunity have ended. S <b> 2 is a process as the communication opportunity receiving unit 112.

  In S3, it is determined whether or not a condition for transmitting the SR defined by the LTE standard is satisfied. If the condition is satisfied, the process proceeds to S4. If the condition is not satisfied, the process of S1 is performed again. In S4, at least SR for requesting allocation of a communication opportunity capable of transmitting the BSR is transmitted to the terminal communication unit 101, and the process of S1 is performed again. S3 and S4 are processing as a request transmission unit.

  In S5, it is determined whether user data can be transmitted in addition to the BSR on the communication opportunity acquired in S2. If transmission is possible, the process proceeds to S6, and if transmission is not possible, the process proceeds to S7.

  In S6, the amount of user data determined to be stored in S1 is compared with the amount of data that can be transmitted at the communication opportunity acquired in S2, and is held in the buffer 111 without being transmitted. Find the amount of user data. A BSR indicating the amount of user data held in the buffer 111 determined in this way is generated and transmitted to the terminal communication unit 101 together with the user data at the communication opportunity acquired in S2. S6 is processing as the report transmission unit 114 and the data transmission unit 115.

  In S7, a BSR indicating the amount of user data determined to be stored in S1 is generated and transmitted to the terminal communication unit 101 according to the communication opportunity acquired in S2. S7 is processing as the report transmission unit 114.

[Operation of base station apparatus 200]
The operation of the base station apparatus 200 will be described along the flowchart of FIG. When communication with the terminal 100 is started, the base station control unit 202 sequentially executes the process shown in FIG. 5 from S11. In S11, the signal received by the base station communication unit 201 is acquired. S11 is processing as the reception processing unit 211. In S12, it is determined whether or not the signal acquired in S11 is SR. When it is SR, it progresses to S13, and when it is not SR, it progresses to S15. S12 is a process as the request acquisition unit 212.

  In S13, it is determined whether or not the generation time is determined for the terminal 100. If the generation time has been determined, the process proceeds to S16, and if not determined, the process proceeds to S14. In S14, the time at which the process is performed is stored as time T0. However, if there is a time stored as T0 due to the execution of the processing of S14 before this time, the time T0 is updated to the time when this processing is performed. S13 and S14 are processes as the time determination unit 215.

  In S15, it is determined whether or not BSR is included in the data acquired in S11. If the BSR is included, the process proceeds to S16, and if not included, the process proceeds to S17. S15 is processing as the report acquisition unit 213.

  In S16, allocation of communication opportunities to the terminal 100 is started. The allocated communication opportunity is transmitted to the terminal 100. S <b> 16 is processing as the allocation unit 218. In the allocation in S16, if the immediately preceding process is S13 or S14, that is, if the determination in S12 is YES due to the reception of SR, at least a communication opportunity capable of transmitting the BSR is given to the terminal 100. Assign. On the other hand, if the immediately preceding process is S15, that is, if the determination in S15 is YES due to the reception of the BSR, allocation to the terminal 100 is started so that the data amount indicated by the BSR can be transmitted. Then, the process proceeds to S17. In addition, when the BSR is received in a situation where the allocation according to the pseudo BSR is performed, the allocation according to the data amount indicated by the pseudo BSR is terminated, and the allocation is performed according to the data amount indicated by the received BSR. That is, when the data amount actually stored in the buffer 111 is received from the terminal 100, the assignment according to the estimated data amount is terminated, and the assignment according to the actual data amount is performed.

  In S17, it is determined whether or not the signal acquired in S11 includes user data. If user data is included, the process proceeds to S18, and if not, the process proceeds to S20. In S18, the user data included in the signal acquired in S11 is transmitted to the transmission destination indicated by the header of the user data. S17 and S18 are processes as the reception processing unit 211.

  In S19, it is determined whether or not the signal acquired in S11 includes low delay data. If so, the process proceeds to S21, and if not, the process proceeds to S20. S19 is processing performed by the data determination unit 2141. In S20, it is determined whether or not the transmission of the low delay data is stopped by determining whether or not the time from the most recent time when the low delay data is received is equal to or greater than the transmission stop threshold. If the time from the most recent time at which the low-delay data is received is equal to or greater than the stop threshold, the process of FIG. 5 is terminated because the transmission is stopped, and if less than the stop threshold, the process proceeds to S21 because the transmission is not stopped . If low-delay data has not been received before this process, the transmission in FIG. 5 is terminated because transmission is stopped. S20 is processing as the transmission stop determination unit 217.

  In S21, it is determined whether or not the generation time is determined. If the generation time is not determined, the process proceeds to S22 to determine the generation time, and if it is determined, the process proceeds to S23. However, even if the generation time is determined, if the determined generation time has passed, the process proceeds to S22 to determine the next generation time.

  In S22, the next generation time is determined. If the generation time is not determined, the first generation time T1 is determined as T1 = T0 + T. If the nth generation time is determined, the (n + 1) th generation time T (n + 1) is determined as T (n + 1) = Tn + T. S21 and S22 are processes as a time determination unit.

  In S23, it is determined whether the generation time determined in S22 has been reached. When it is determined that the generation time has been reached, the process proceeds to S24, and when it is determined that the generation time has not been reached, the processing shown in FIG. 5 is terminated. In S24, a pseudo BSR indicating the data amount D is generated. S23 and S24 are processes as the pseudo report generation unit 216.

  In S25, allocation to the terminal 100 is started so that the data amount D indicated by the pseudo BSR generated in S24 can be transmitted, and the process shown in FIG. The allocated communication opportunity is transmitted to the terminal 100. However, when the allocation according to the BSR is performed, the allocation according to the data amount indicated by the BSR is continued, and the communication opportunity according to the data amount indicated by the generated pseudo BSR is not performed. That is, when the data amount actually stored in the buffer 111 can be received from the terminal 100, the allocation is performed according to the actual data amount, not the estimated data amount. S25 is a process as the allocation unit 218.

[Example of assignment by pseudo BSR]
An operation example in which a communication opportunity is assigned to the terminal 100 according to the data amount indicated by the pseudo BSR will be described with reference to FIG.

  Since the low delay data is stored in the buffer 111 at time Ta, the terminal 100 transmits an SR to the base station apparatus 200 and requests to allocate a communication opportunity for transmitting the BSR and the low delay data. The base station apparatus 200 that has received the SR stores the received time Ta as the reference time T0, and assigns a communication opportunity capable of transmitting the BSR to the terminal 100, and at time Tb, assigns the assigned communication opportunity to the terminal 100. Send.

  The terminal 100 transmits a BSR at time Tc according to the assigned communication opportunity. Receiving the BSR, the base station apparatus 200 allocates a communication opportunity capable of transmitting the data amount indicated by the BSR to the terminal 100, and transmits the allocated communication opportunity to the terminal 100 at time Td.

  The terminal 100 transmits the low delay data stored at the time Ta at the time Te according to the assigned communication opportunity. The base station apparatus 200 that has received the low-delay data determines the reference time T0, that is, the time Tf at which the period T has elapsed from the time Ta, as the generation time.

  The low delay data is stored again in the buffer 111 at time Tf when the period T has elapsed from time Ta, and the terminal 100 transmits SR. At this time, the base station apparatus 200 generates a pseudo BSR when the time Tf that is the generation time is reached, and transmits a communication opportunity assigned according to the pseudo BSR at the time Tg. The terminal 100 transmits the low delay data stored at the time Tf at the time Th according to the received communication opportunity.

[Summary of Embodiment]
As described above, according to the embodiment described above, the time determination unit 215 determines the generation time according to the time when the low-delay data is predicted to be stored in the buffer. At the generation time determined by the time determination unit 215, the pseudo report generation unit 216 generates a value obtained by estimating the amount of low delay data stored in the buffer as a pseudo BSR. The assigning unit 218 assigns communication opportunities to the terminals according to the amount of low delay data indicated by the pseudo BSR. Therefore, communication opportunities are allocated according to the amount of low-delay data estimated to be stored at the generation time determined according to the time when low-delay data is predicted to be stored in the buffer.

  Accordingly, regardless of whether or not the base station apparatus 200 receives a BSR indicating that the low delay data is stored at the generation time according to the time when the low delay data is stored in the buffer 111, the low delay data Can be assigned to the terminal 100. Therefore, it is possible to suppress the delay from the time when the data is stored in the buffer 111 until the data is transmitted according to the time delay until the base station apparatus 200 receives the BSR.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, The following modification is also contained in the technical scope of this invention, Furthermore, the summary other than the following is also included. Various modifications can be made without departing from the scope. In the following description, elements having the same reference numerals as those used so far are the same as the elements having the same reference numerals in the previous embodiments unless otherwise specified. Further, when only a part of the configuration is described, the above-described embodiment can be applied to the other parts of the configuration.

<Modification 1>
In the embodiment, the pseudo BSR is generated for low-delay data stored in the buffer 111 at a predetermined period and a predetermined amount. However, there is no need for a strictly constant period and a constant amount, and there may be fluctuations in a range in which the time determination unit 215 and the pseudo report generation unit 216 can achieve the purpose. Further, the pseudo BSR may be generated by estimating the amount of data stored in the buffer without distinguishing the data according to the necessity of delay suppression.

  For example, the amount of low delay data stored in the buffer 111 may vary within a predetermined range. In this case, for example, the upper limit value of the stored amount can be determined as the data amount D indicated by the pseudo BSR.

  Further, the determined generation time may be different from the time at which the low-delay data is actually stored because the period is not constant. An example of operation in such a case will be described with reference to FIG. It is assumed that the generation time t14 has been determined. Since the low delay data is stored at time t11, terminal 100 transmits SR, a communication opportunity assigned at time t12 is transmitted, and terminal 100 transmits BSR at time t13.

  At this time, it is conceivable that the base station apparatus 200 cannot receive the BSR and is lost. If a communication opportunity is not transmitted for a predetermined period from time t13 at which the BSR is transmitted, the terminal 100 retransmits the SR, requests allocation of the communication opportunity, and retransmits the BSR, assuming that the BSR is lost. In this way, when the BSR is lost and the BSR is retransmitted, the time when the BSR is retransmitted is delayed from the time t13 according to a predetermined period for determining that the BSR is lost. For example, the time at which this BSR is retransmitted is t15.

  At this time, if the time t14 at which the pseudo BSR is generated is before the time t15 at which the BSR is retransmitted, a communication opportunity for transmitting low-delay data according to the pseudo BSR can be allocated without waiting for the retransmission of the BSR. It becomes possible.

  Thus, even if the generation time is different from the time at which the low-delay data is stored, if the base station device 200 is before the time when the BSR is received, the time until the base station device 200 receives the BSR. Accordingly, the occurrence of a delay at the time when low-delay data is transmitted is suppressed. That is, the cycle in which the low-delay data is stored may have a variation that allows the time determination unit 215 to determine the generation time so that it is before the time when the base station apparatus 200 receives the BSR.

<Modification 2>
In the embodiment, the data amount D and the period T are stored in advance in the ROM included in the base station control unit 202. However, the data amount D and period T determined from the amount and period of the actually received low delay data may be used.

<Modification 3>
In the embodiment, a case has been described in which the number of terminals 100 to which communication opportunities are assigned according to the pseudo BSR is described. However, even if a pseudo BSR is generated for each of the plurality of terminals 100 and a communication opportunity is assigned according to the generated pseudo BSR. Good. When generating pseudo BSRs for a plurality of terminals 100, as shown in FIG. 8, pseudo BSRs having different data amounts may be generated at different periods for each terminal 100.

<Modification 4>
In the embodiment, the application unit 120 has one function for generating low-delay data, but may have a plurality of functions for generating low-delay data. In this case, as shown in FIG. 9, a value obtained by summing the amounts of low-delay data generated by a plurality of functions at that time may be sequentially generated as a pseudo BSR for the terminal 100.

<Modification 5>
In the embodiment, the terminal determination unit 214 includes a data determination unit 2141 and determines whether the user data is a low delay terminal based on whether low delay data is included in the user data. However, the determination method is not limited to this. For example, if the type of device that uses the terminal 100 and the type ID that identifies the device are transmitted to the terminal 100 and the type ID indicates that the device that uses the terminal 100 is a vehicle, the terminal may be determined to be a low-delay terminal. .

1: Wireless communication system 100: Terminal 101: Terminal communication unit 102: Terminal control unit 110: Communication control unit 111: Buffer 112: Communication opportunity reception unit 113: Request transmission unit 114: Report transmission unit 115: Data transmission unit 120: Application Unit 200: Base station apparatus 201: Base station communication unit 202: Base station control unit 211: Reception processing unit 212: Request acquisition unit 213: Report acquisition unit 214: Terminal determination unit 215: Time determination unit 216: Pseudo report generation unit 217 : Transmission stop determination unit 218: Allocation unit 2141: Data determination unit

Claims (8)

A base station device (200) that is a wireless communication device used in the wireless base station, and a terminal (100) that is a wireless communication device that wirelessly transmits data stored in the buffer to the base station device,
The base station device
A reception processing unit (211) that receives a signal transmitted by the terminal;
A report acquisition unit (213) for acquiring a buffer status report indicating the amount of the data stored and held in the buffer from the signal received by the reception processing unit;
An allocation unit (218) that allocates a communication opportunity to the terminal according to the amount of the data indicated by the buffer status report received by the report acquisition unit;
The terminal is a wireless communication system that transmits the data to the base station apparatus according to the communication opportunity assigned by the assigning unit,
The base station device
A pseudo report generation unit (216) that generates a pseudo buffer status report indicating a value obtained by estimating the amount of the data held in the buffer;
A time determination unit (215) for determining a generation time at which the pseudo report generation unit generates the pseudo buffer status report according to a time at which the data is predicted to be stored in the buffer;
The pseudo report generation unit generates the pseudo buffer status report at the generation time,
The wireless communication system, wherein the allocating unit allocates the communication opportunity to the terminal according to the amount of data indicated by the pseudo buffer status report even when the pseudo report generation unit generates the pseudo buffer status report. In claim 1,
The data is normal data and low-delay data in which a predetermined amount is stored in the buffer at a predetermined cycle, the data having a large need to suppress delay compared to the normal data. Including
The pseudo report generation unit generates the pseudo buffer status report indicating a value obtained by estimating the amount of the low delay data held in the buffer based on the predetermined amount,
The time determination unit determines the generation time according to a time at which the low-delay data is stored in the buffer, which is predicted based on the predetermined period.
The said allocation part is a radio | wireless communications system which allocates the said communication opportunity to the said terminal according to the quantity of the said low delay data which the said pseudo buffer status report shows, when the said pseudo report production | generation part produces | generates the said pseudo buffer status report. In claim 2,
The base station device
A terminal determination unit (214) for determining whether or not the terminal is a low delay terminal that transmits the low delay data;
The said pseudo report production | generation part is a radio | wireless communications system which produces | generates the said pseudo buffer status report about the said terminal which the said terminal judgment part judged as the said low delay terminal. In claim 3,
The terminal determination unit
A data determination unit (2141) for determining whether the data received by the reception processing unit is the low-delay data;
When the data determination unit determines that the data received by the reception processing unit is the low delay data, the terminal determination unit determines that the terminal that transmitted the data is the low delay terminal. Wireless communication system. In claim 4,
The base station device
A transmission stop determination unit (217) that determines whether the time from the most recent time when the terminal transmits the low delay data is equal to or greater than a transmission stop threshold for determining that transmission of the low delay data is stopped. )
The said pseudo report production | generation part is a radio | wireless communications system which stops the production | generation of the said pseudo buffer status report, when the said transmission stop judgment part judges that it is more than a transmission stop threshold value. In any one of Claim 2 to 5,
When the pseudo report generation unit generates the pseudo buffer status report in a predetermined period determined based on the time at which the report acquisition unit receives the buffer status report, the allocating unit generates the pseudo buffer status report. Rather, the wireless communication system assigns the communication opportunity according to the amount of data indicated by the buffer status report. In any one of Claim 2 to 6,
A plurality of the terminals in which at least one of a period in which the low delay data is stored in the buffer or an amount of the low delay data stored in the buffer is different from each other;
The time determination unit determines the generation time of each terminal based on a cycle in which the low-delay data is stored in the buffer of the terminal,
The said pseudo report production | generation part is a radio | wireless communications system which each produces | generates the said pseudo buffer status report of each said terminal according to the value which estimated the amount of the said low delay data stored in the said buffer of the said terminal. A reception processing unit (211) that receives a signal including the data transmitted by a terminal that is a wireless communication device that wirelessly transmits data stored in the buffer;
A report acquisition unit (213) for acquiring a buffer status report indicating the amount of the data stored and held in the buffer from the signal received by the reception processing unit;
An allocation unit (218) that allocates a communication opportunity to the terminal according to the amount of data indicated by the buffer status report received by the report acquisition unit, and a base station device that is a radio communication device used in a radio base station. And
A pseudo report generation unit (216) that generates a pseudo buffer status report indicating a value obtained by estimating the amount of the data held in the buffer;
A time determination unit (215) for determining a generation time at which the pseudo report generation unit generates the pseudo buffer status report according to a time at which the data is predicted to be stored in the buffer;
The pseudo report generation unit generates the pseudo buffer status report at the generation time,
The allocation unit is a base station apparatus that allocates the communication opportunity to the terminal according to the amount of data indicated by the pseudo buffer status report even when the pseudo report generation unit generates the pseudo buffer status report.

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