JP5505157B2 - Base station and communication control method - Google Patents

Description

  The present invention relates to a technical field of a base station that performs communication with a user terminal and a communication control method in the base station.

  In mobile communication systems including this type of base station, next-generation mobile communication systems that enable high-speed data communication are being studied as the capacity of content transmitted via a network increases. In recent years, the transmission speed between a base station and a mobile terminal has been increased by a standard such as HSDPA (High Speed Downlink Packet Access) or HSUPA (High Speed Uplink Packet Access). Development of next-generation communication standards such as LTE (Long Term Evolution) is being promoted as a technology for realizing higher speed.

  While the transmission rate in the so-called wireless section between the base station and the mobile terminal is improved, access exceeding the processing capacity of the content server occurs, and as a result, the response to the mobile terminal may be reduced. This is thought to be due to congestion in the content server and congestion in the core network of the so-called wired section connecting the content server and the base station, because large-volume content transmission requests are concentrated on the content server. .

  When the content requested to be transmitted from the mobile terminal does not reach the time limit due to a decrease in the response to the mobile terminal, the content being transmitted is discarded due to timeout. For this reason, the mobile terminal side makes a transmission request again, which leads to an increase in the traffic volume in the wireless section because of the retransmission of the content in response to the transmission request.

  In order to control communication in the case where congestion occurs in the content server or the base station due to an increase in traffic volume in this way, development of technology for reducing the load on the base station and the control station that controls the base station is underway. . For example, the following prior art documents describe a technique for reducing the congestion state by reducing traffic by rejecting a line connection request from a mobile terminal in a state where congestion occurs.

JP 2008-28431 A International Publication No. 2005/2270 Pamphlet JP 2006-319487 A

  The conventional base station controls communication for each QoS (Quality of Service) class indicating communication quality set according to the type of data transmitted to the mobile terminal in the wired section. Specifically, the above-mentioned congestion is dealt with by changing the communication priority according to the service type, the charge class, or the traffic situation according to the contract condition for each mobile terminal, in other words, for each user.

  On the other hand, for users belonging to the same QoS class, since uniform transmission control is performed, retransmission that occurs when congestion occurs may hinder data transmission to other users belonging to the same QoS class. There is sex. Further, when a delay occurs in the communication in the wired section due to some factor, there is a possibility of causing a communication delay in the wireless section for other users.

  It is an object of the present invention to provide a base station and a communication control method that enable efficient data transmission in a wireless section according to a communication state in a wired section.

  In order to solve the above problems, a disclosed base station is connected to a data server via a core network, and communicates data between the data server and one or more mobile terminals located in a radio section under the data server. I do. Further, the base station determines a communication priority for each of the one or more mobile terminals based on the measurement means for measuring a communication state for the one or more mobile terminals in the core network. Priority determination means for determining.

  The disclosed communication control method includes a measurement process and a priority determination process. In the measurement process, an operation similar to the operation performed by the above-described measurement means is performed. In the priority determination step, an operation similar to the operation performed by the priority determination means described above is performed.

  According to the above-described configuration, it is possible to determine a data transmission schedule in the wireless section connecting the base station and the mobile terminal according to the communication state in the core network connecting the base station and the data server. Therefore, efficient communication in the wireless section is possible without being affected by the data communication delay in the wired section.

It is a figure which shows the whole structure of a mobile communication system. It is a block diagram which shows the basic composition of eNB. It is a block diagram which shows the function part which the BB process part inside eNB has. It is a block diagram which shows the detailed function part of a signal processing part. It is a figure which shows the example of the table stored in a priority management database. It is a sequence diagram which shows the process at the time of the download request of the content from a user. It is a sequence diagram which shows the process at the time of the download of the content from a data server. It is a sequence diagram which shows the process which determines the priority of packet transmission. It is a figure which shows the outline | summary of the packet transmission for every QoS class. It is a figure which shows the outline | summary of a priority determination process and scheduling. It is a figure which shows the outline | summary of a priority determination process and scheduling. It is a figure which shows the outline | summary of the packet transmission when not performing the scheduling according to a wired area. It is a figure which shows the outline | summary of the packet transmission when not performing the scheduling according to a wired area.

  Embodiments for carrying out the invention will be described below.

(1) Configuration Example A basic configuration of a mobile communication system 1 is shown with reference to FIG.

  As shown in FIG. 1, in the mobile communication system 1, an eNB (e Node B) 100, which is an example of a disclosed base station, is connected to a plurality of data servers 200a to 200c via a core network. The core network is configured by a wired connection such as a data communication cable. Hereinafter, the transmission path between the base station 100 and the data servers 200a to 200c in the core network may be described as a wired section. Further, when the description is made without distinguishing each of the data servers 200a to 200c, the data server 200 will be referred to as the data server 200.

  The eNB 100 forms a cell by transmitting radio waves for communication from an antenna, and communicates with mobile terminals (UE: User Equipment) 300a to 300c of users located in the cell. Hereinafter, the transmission path between the eNB 100 and the UEs 300a to 300c may be referred to as a radio section. Moreover, when it demonstrates without distinguishing each of UE300a thru | or 300c, it demonstrates as UE300 and demonstrates.

  With reference to FIG. 2, the structure of eNB100 is demonstrated. FIG. 2 is a block diagram illustrating a hardware configuration of the eNB 100.

  The eNB 100 includes an RRH (Remote Radio Head) 110 and a BBU (Base Band Unit: baseband processing unit) 120, and further includes a BB (baseband) processing unit 130 and a CNT (Control: device control) in the BBU 120. Part) 140.

  The RRH 110 is configured to transmit and receive signals to and from the radio section. The RRH 110 transmits a signal processed in the BBU 120 to the radio section and inputs a signal received from the radio section to the BBU 120.

  The BBU 120 performs processing for changing the content data received from the data servers 200a to 200c via the core network to a format for transmitting to the UEs 300a to 300c. Further, the BBU 120 performs processing for transmitting a message transmitted from the UEs 300a to 300c to the data servers 200a to 200c via the core network.

  The BB processing unit 130 modulates or demodulates the input data, thereby generating content data to be transmitted to the UEs 300a to 300c from the baseband signal transmitted from the data servers 200a to 200c via the core network. get. In addition, the BB processing unit 130 performs data scheduling when transmitting a content data packet to a wireless section. A more detailed configuration and function of the BB processing unit 130 will be described in detail later.

  The CNT 140 is configured to monitor and control the operation of the entire eNB 100. Further, the CNT 140 includes an interface for performing communication with the data servers 200a to 200c via the core network.

  With reference to FIG. 3, the function which the BB process part 130 of eNB100 has is demonstrated. FIG. 3 is a block diagram illustrating functions of the BB processing unit 130 as functional units. Each functional unit is described as an independent configuration for convenience, but is not limited to a configuration having an entity, and may be a program described in software, for example.

  The RRH interface unit 131 is an interface for inputting / outputting data to / from the RRH 110. The power control unit 132 is a functional unit that controls output of a signal transmitted by the RRH 110. Modulation section 133 is a functional section that modulates a transmission signal to UE 300. The demodulator 134 is a functional unit that demodulates a received signal from the UE 300. The CNT interface unit 135 is an interface for inputting / outputting data to / from the CNT 140.

  The signal processing unit 150 is a functional unit that performs signal processing between the core network and the wireless section. In addition, it has a function of scheduling data when a packet of content data is transmitted to the wireless section.

  In the example illustrated in FIG. 3, the signal processing unit 150 includes a signal control unit 151, a measurement unit 152, a priority management database 153, and a scheduling unit 154.

  The signal control unit 151 performs transmission / reception control of signals exchanged with various server devices and communication devices on the core network side connected to the UE 300. In addition, the signal control unit 151 performs link control for connecting the inter-office link with the opposite node, control of a connection sequence for performing call connection in response to a request from the data server 200 or the UE 300, and call Secure and release resources necessary for connection. The signal control unit 151 performs control to reduce congestion by regulating the traffic amount when data congestion occurs in a wired section. Further, the signal control unit 151 analyzes and creates a control signal for communication with the data server 200, and controls the operation of the entire signal processing unit 150 by managing the operation sequence of each unit.

  The measuring unit 152 measures a communication state such as a response time from request to transmission of content data in a wired section to a transmission and a signal reception amount indicating a reception size of the data unit time for the data server 200. The measurement unit 152 stores the measured communication state in the priority management database 153 as information related to priority in scheduling described later.

  The priority management database 153 is a database that stores information related to the communication state of content data in units of users measured by the measurement unit 152 or the like. The information related to the communication state of content data in units of users is intended to indicate information indicating the communication state of content data related to a content download request for each user. For example, in the priority management database 153, information related to the communication state of content in response to a download request from the UE 300a and information related to the communication state of content in response to a download request from the UE 300b are stored separately.

  The scheduling unit 154 determines a transmission schedule for transmitting a transmission packet such as content data transmitted from the wired section to the wireless section, and assigns it to the slot of the transmission packet.

  FIG. 4 shows a more detailed configuration of the functional unit of the signal processing unit 150.

  The scheduling unit 154 includes a priority determination unit 155 and a wireless transmission buffer 156. Based on information related to the communication state of the content data stored in the priority management database 153 (for example, information related to the user of the received packet), the priority determination unit 155 Instructs the priority of transmission.

  In addition, the signal processing unit 150 includes wireless reception buffers 157, wired transmission buffers 158, and wired reception buffers 159. The wireless transmission buffer 156 is a buffer that temporarily transmits a transmission packet that is transmitted to the wireless section, and preferably from the data server 200. The radio reception buffer 157 is a buffer that temporarily stores a download request packet or the like transmitted from each UE 300 via a radio section. The wired transmission buffer 158 is a buffer that temporarily stores a request packet according to a download request packet from the UE 300 that is transmitted to the wired section. The wired reception buffer 159 is a buffer that temporarily stores a content data packet transmitted from each of the data servers 200 via a wired section. The signal control unit 151 temporarily stores a packet input via the RRH interface unit 131 or the CNT interface unit 135 in each buffer, and processes each data.

  Note that the scheduling unit 154 has a plurality of wireless transmission buffers 156, and for each wireless transmission buffer 156, the data type (or QoS (Quality of Service) class of content requested by the user for each user) ) To store the packet temporarily in each buffer. The scheduling unit 154 determines a transmission schedule within the same QoS class among the packets stored in the wireless transmission buffer 156.

  FIG. 5 is an example of information stored in the priority management database 153. The priority management database 153 shown in FIG. 5 includes three types of tables: a measurement table 153a, a totaling table 153b, and a priority determination table 153c for storing information related to the communication state of content data in units of users. Has a table.

  The measurement table 153 a is a table that stores information indicating a communication state of content data from the data server 200 measured by the measurement unit 152. The measurement table 153a stores a TE-ID (Tunnel Endpoint Identifier) for identifying the request call (in other words, the user or the UE 300) upon reception of a content download request transmitted from the UE 300. At this time, the measurement table 153a stores each TE-ID with an identification number (No). At this time, the measurement table 153a stores the time when the content download request is received (request reception time) for each TE-ID.

  After the content download request is transmitted to the data server 200 via the core network by the CNT 140, the measurement table 153a receives the response from the data server 200 in response to the request, and the reception time (response reception time), And the data size (response received amount) of the content transmitted from the data server 200 together with the response is stored. At this time, the measurement table 153a calculates a response time, which is a required time from the request reception time to the response reception time, and stores the calculation result.

  Note that each time there is a download request from the same TE-ID, the measurement table 153a adds the data size transmitted from the data server 200 in response to the request to the reception response amount stored in the table, and sets the value. Update. Also, a response time is calculated for a response from the data server 200 in response to a download request from the same TE-ID, and the calculated result is added to the response time stored in the table to update the value.

  The measurement table 153a may include a data field for storing information to be measured in accordance with the operation of the measurement unit 152 in addition to the data field described above. For example, the number of packets transmitted from the data server 200 in response to a download request from the same TE-ID (in other words, the number of packet transmissions) may be stored as information related to the communication state of content data.

  For example, after a monitoring timer that indicates a predetermined measurement period, which will be described later, times out, the measurement unit 152 ends the measurement of information related to the communication state of the content data, and the measurement table 153a ends the update of the data field. At this time, the measurement table 153a passes the data to be stored to the aggregation table 153b.

  The tabulation table 153b is a table for tabulating the measurement values of the information related to the communication state of the content data collected in the measurement table 153a and calculating the wireless section priority. The tabulation table 153b is similar to the measurement table 153a, in addition to the data fields for storing the TE-ID, request reception time, response reception amount, response reception time, response time, etc. It has a data field for storing the priority. The priority determination unit 155 calculates the priority for determining the transmission schedule in the wireless section with reference to the data stored in the tabulation table 153b.

  For example, the tabulation table 153b may calculate the priority of data transmission to the radio section for each TE-ID (in other words, for each user) as the transmission order in the transmission schedule, and the data included in the transmission packet Alternatively, it may be calculated in the form of a weighting coefficient that defines the ratio. In the example of FIG. 5, it is calculated and stored in the transmission order mode. A specific method for calculating the priority will be described in detail later. The tabulation table 153b passes the calculated wireless section priority to the priority determination table 153c.

The priority determination table 153c stores the radio section priority for each TE-ID (in other words, for each user) calculated in the aggregation table 153b. As shown in FIG. 5, the priority determination table 153c has, for example, a data field for storing the TE-ID for each call and the wireless section priority passed from the aggregation table. The scheduling unit 154 refers to the priority determination table 153c when determining the transmission schedule of transmission packets to the wireless section, and determines the schedule based on the stored wireless section priority.
(2) Operational Example A scheduling process of transmission data to the radio section by the eNB 100 will be described with reference to FIGS.

  FIG. 6 is a sequence diagram illustrating a processing flow of the eNB 100, the data server 200, and the UE 300 when a content download request from the UE 300 is received.

  First, one UE 300 among a plurality of UEs located in the cell of the eNB 100 makes a content download request to the eNB 100 (step S101). The measurement unit 152 of the eNB 100 acquires the download request TE-ID and the request reception time (step S102), and stores them in the measurement table 153a (step S103).

  The signal control unit 151 of the eNB 100 transmits a content request packet to the data server 200 having the content requested to be downloaded from the UE 300 (step S104).

  With reference to FIG. 7, the flow of processing when a data packet is transmitted from the data server 200 in response to a content request packet will be described.

  Upon receiving the content request packet, the data server 200 transmits the requested content data packet to the transmission source eNB 100 (step S201).

  The signal control unit 151 of the eNB 100 obtains the GTP layer TE-ID of the received packet (step S202), and determines whether or not the packet transmission for the TE-ID is the first time (step S203). The signal control unit 151 determines whether or not the packet is transmitted for the first time, for example, by referring to the response reception amount of the packet stored in the measurement table 153a.

  When transmission of a packet for the TE-ID is the first time (step S203: Yes), a response reception time that is a packet reception time is stored in the data field of the TE-ID (step S204). Further, the measurement table 153a calculates a response time from the stored request reception time and response reception time for the corresponding TE-ID and stores the response time (step S205).

  After storing the response time or when the packet is not the first transmission packet for the same TE-ID (step S203: No), the measurement unit 153 stores the data size of the received packet in the measurement table 153a as the response reception amount. Store (step S206).

  In addition, eNB100 performs the process with respect to the download request of the content from UE300 mentioned above, and the process at the time of the packet reception from the data server 200 in parallel with respect to each of UE300 which exists in a radio area. For this reason, in the measurement table 153a in the priority management database 153, the communication state of content data for each of a plurality of TE-IDs acquired in response to a content download request from a plurality of UEs 300 Is stored.

  The signal control unit 151 stores the received packet from the data server 200 in the wireless transmission buffer assigned to the UE 300 that requested the packet (step S207). Thereafter, the scheduling unit 154 of the eNB 100 determines a transmission schedule for transmitting the data stored in the buffer to the radio section (step S208). Thereafter, the eNB 100 transmits content data to the UE 300 via the radio section in accordance with the determined transmission schedule (step S209).

  The signal control unit 151 calculates the response time data field of the measurement table 153a without determining whether or not the packet transmission for the TE-ID is the first time in step S203. You may perform the process which adds a response time simply. Such an operation can provide the same effect as the above-described operation.

  With reference to FIG. 8, the flow of the scheduling process for determining the data transmission schedule to the radio section by the scheduling unit 154 will be described.

  When the content data packet is transmitted from the data server 200 described above, the scheduling unit 154 counts time using an internal monitoring timer. The scheduling unit 154 starts the following scheduling process when the monitoring timer times out (step S301). The monitoring timer is a timer included in the scheduling unit 154 and has a configuration that defines a predetermined period for collecting information related to the communication state.

  After the timeout of the monitoring timer, the scheduling unit 154 first gives an instruction to pass the data stored in the measurement table 153a in the priority management database 153 to the aggregation table 153b (step S302). In addition, the scheduling unit 154 clears past data stored in the priority determination table 153c in the priority management database 153 (step S303).

  Next, the priority determination unit 155 calculates the weighting coefficients W1 and W2 for each TE-ID using the data passed to the aggregation table 153b (steps S304 and S305). Specifically, the priority determination unit 155 calculates the weighting coefficient W1 so that data transmission to the wireless section is preferentially performed for the TE-ID with a short response time. In addition, the priority determination unit 155 weights the data so that the data transmission to the wireless section is preferentially performed for the TE-ID having a large response reception amount that is the sum of the data sizes of the transmission packets from the data server 200. W2 is calculated.

  Next, the priority determination unit 155 calculates the weighting coefficient W for determining the final wireless section priority or the priority based on the weighting coefficients W1 and W2 calculated in the tabulation table 153b ( In step S305, the priority is stored in the priority determination table 153c (step S306). For example, the priority determination unit 155 may determine the final weighting factor W by adding, multiplying, or averaging the weighting factors W1 and W2.

  Thereafter, the scheduling unit 154 starts measuring the monitoring timer (step S308).

(3) Priority Determination Processing Example A priority determination method for determining a transmission schedule for the UE 300 by the priority management database 153 will be described below.

  FIG. 9 shows an image of packet transmission to the radio section based on the transmission schedule according to the priority by the eNB 100. FIG. 9 is a diagram conceptually illustrating a configuration of an operation that the scheduling unit 154 allocates from the wireless transmission buffer 156 to the slot of the transmission packet in the wireless section. In the example of FIG. 9, the eNB 100 is connected to a plurality of UEs 300 including the UEs 300a to 300c via the radio section. In the following description, each UE 300 will be described as a user. For example, UE 300a will be described as user A and UE 300b as user B, respectively.

  In the example of FIG. 9, a state is shown in which individual UEs 300 are communicating with different QoS (Quality of Service) classes. The eNB 100 determines a transmission schedule by assigning different radio-oriented transmission buffers 156a to 156d for each QoS class. Specifically, users A, B, and C perform voice communication, and transmission packets transmitted from the data server 200 are stored in the wireless transmission buffer 156a. Users D, E, and F are performing image communication (such as videophone calls), and transmission packets transmitted from the data server 200 are stored in the wireless transmission buffer 156a. Users G, H, and I access an i-mode (registered trademark) site and the like, and transmission packets transmitted from the data server 200 are stored in the wireless transmission buffer 156a. The users J, K, and L perform mail transmission / reception, and the transmission packet transmitted from the data server 200 is stored in the wireless transmission buffer 156a.

  The scheduling unit 154 of the eNB 100 determines a transmission schedule for the radio section by taking out the queue according to the priority from the transmission packet transmission queue stored in the radio transmission buffers 156a to 156d for each QoS class.

  A method for calculating the weighting coefficient W1, which is an example of an index for determining the priority, will be described with reference to FIG. FIG. 10A is an example of data stored in the aggregation table 153b in the priority management database 153 indicating information related to the communication state of content data for each user. In the example of FIG. 10A, the priority management database 153 collects the average response time, which is the average value of the response time, and the number of receptions of packets from the data server 200 as information related to the communication state of the content data. ing.

  In the example of FIG. 10A, the average response time for packet transmission to user A is 1 sec, the average response time for packet transmission to user B is 10 sec, and the average response time for packet transmission to user C is 5 sec. Is stored.

  FIG. 10B shows an outline of packet transmission in the example shown in FIG. In the example of FIG. 10B, the data servers 200a to 200c storing the content of the same QoS class transmit content data packets to the UEs 300a to 300c corresponding to the users A to C. Specifically, the data server 200a transmits a packet four times to the UE 300a. The data server 200b transmits a packet twice to the UE 300b. The data server 200c transmits a packet three times to the UE 300c.

  For example, the priority determination unit 155 divides the average response time of all users within a predetermined period by the average response time of one user, thereby serving as an index of the priority of data transmission in the wireless section for the user. A weighting coefficient W1 is calculated.

  In the example of FIG. 10A, the average response time of all users, that is, users A, B, and C, is (1 * 4 + 10 * 2 + 5 * 3) / () based on the average response time and the number of packet receptions for each user. 4 + 2 + 3) = 39 (sec). By dividing the average response time of all users by the average response time of individual users, the weighting coefficient W1 for each user is calculated. In the example of FIG. 10A, the weighting coefficient W1 of the user A is calculated as 39.0, the weighting coefficient W1 of the user B is 3.9, and the weighting coefficient W1 of the user C is calculated as 19.5. Based on the respective ratios, the weighting coefficient W1 of each of the user A, the user B, and the user C is calculated as 10: 1: 5.

  Note that the priority determination unit 155 may determine the priority of packet transmission to the wireless section based only on the weighting coefficient W1. In other words, the priority determination unit 155 may determine the priority of packet transmission to the wireless section without being based on the weighting coefficient W2. In this case, the priority determination unit 155 determines the packet transmission priority in the order of the packet for the user A, the packet for the user C, and the packet for the user B in descending order of the weighting coefficient W1.

  The scheduling unit 154 of the eNB 100 determines the transmission schedule (in other words, the transmission order) of each packet received from the data servers 200a to 200c according to the wireless section priority calculated as illustrated in FIG. To do. In an example illustrated in FIG. 10B, the scheduling unit 154 determines the transmission schedule based on the wireless section priority based on the weighting coefficient W1.

  As another example of the process for determining the priority, a method for calculating the weighting coefficient W2, which is an example of an index for determining the priority, will be described with reference to FIG. FIG. 11A is an example of data stored in the aggregation table 153b in the priority management database 153 indicating information related to the communication state of content data for each user. In the example of FIG. 11A, the priority management database 153 collects a signal reception amount that is a data size received from the data server 200 as information related to a communication state of content data.

  In the example of FIG. 11A, the packet signal reception amount for the user A is stored as 6 BPS, the packet signal reception amount for the user B is 2 BPS, and the packet signal reception amount for the user C is stored as 10 BPS.

  FIG. 11B shows an outline of packet transmission in the example shown in FIG. In the example of FIG. 11B, the data servers 200a to 200c storing the content of the same QoS class transmit content data packets to the UEs 300a to 300c corresponding to the users A to C. Specifically, the data server 200a transmits 2 BPS packets to the UE 300a three times. The data server 200b transmits a 2 BPS packet once to the UE 300b. The data server 200c transmits a 5 BPS packet twice to the UE 300c.

  The priority determination unit 155, for example, a weighting coefficient W2 that is an index of the priority of data transmission in a wireless section so that data transmission is performed preferentially for a user with a large amount of signal reception within a predetermined period. Is calculated.

  In the example of FIG. 11A, the priority determination unit 155 determines the weighting coefficient W2 of each of the users A, B, and C from the ratio of the signal reception amounts of the users A, B, and C by 3: 1. : Calculated as 5.

  Note that the priority determination unit 155 may determine the priority of packet transmission to the wireless section based only on the weighting coefficient W2. In other words, the priority determination unit 155 may determine the priority of packet transmission to the wireless section without being based on the weighting coefficient W1. In this case, the priority determination unit 155 determines packet transmission priorities in the order of the packet for the user C, the packet for the user A, and the packet for the user B in descending order of the weighting coefficient W2.

  The scheduling unit 154 of the eNB 100 determines the transmission schedule (in other words, the transmission order) of each packet received from the data servers 200a to 200c according to the wireless section priority calculated as illustrated in FIG. To do. In the example illustrated in FIG. 11B, the scheduling unit 154 determines the transmission schedule based on the wireless section priority based on the weighting coefficient W2.

  In the example shown in FIGS. 10 and 11, the wireless section priority that defines the packet transmission order to the wireless section is determined based on one of the weighting factors W1 or W2. The wireless section priority may be determined based on both the weighting coefficient W1 and the weighting coefficient W2. Thereby, since the wireless section priority can be determined based on both the response time of the data server 200 and the data size of the transmitted packet, it is possible to determine a more preferable packet transmission schedule in the wireless section. It becomes possible.

  As described above, according to the operation of the eNB 100 described above, based on the communication state in the wired section between the eNB 100 and the data server 200, the transmission schedule of data to be transmitted to the wireless section in which the eNB 100 is connected to the UE 300 is determined. The

  The priority determination unit 155 included in the eNB 100 determines priorities such as the packet transmission order for the wireless section according to the transmission state of the packet from the data server 200 in the core network that is a wired section. The scheduling unit 154 incorporates the packet from the data server 200 into a radio frame to be transmitted to the radio section according to the priority determined in this manner, thereby setting the packet transmission order, in other words, the packet transmission schedule. decide.

  When the above-described transmission schedule determination operation by the eNB 100 is not performed, the data for the UE 300 is, for example, a transmission schedule based on the type of data transmitted from each of the data servers 200 and the QoS class defined for each type. Is determined. As described above, examples of packet transmission in the mobile communication system 1 ′ that is not scheduled by the eNB 100 are shown in FIGS. 12 and 13.

  As shown in FIG. 12, the eNB 100 ′ of the mobile communication system 1 ′ incorporates the packets for the UEs 300′a to 300′c (in other words, the users A to C) into the radio frame in the order received, and the capacity of the radio frame When it is satisfied, it transmits to the radio section.

  In the example of FIG. 12, for the eNB 100 ′, from the data servers 200′a to 200′c, the packet a for the user A is four times, the packet b for the user B is twice, and the packet c for the user C is It has been transmitted three times. The eNB 100 ′ incorporates the radio frames transmitted in the radio section in the order of a, b, c, a, c, a, a in the order in which the packets are received. For this reason, the packet b for the user B and the packet c for the user C are not incorporated into the radio frame, but are incorporated into the radio frame transmitted next time. As a result, the content can be used in the UE 300'a of the user A who has received all the packets. On the other hand, the UE 300'b of the user B and the UE 300'c of the user C who have received only a part of the packets have to wait for reception of the next radio frame until the content becomes available. At this time, if the data server 200'b or the data server 200'c cannot quickly transmit the remaining packets due to some cause, a timeout may occur, and the already transmitted packet may become invalid. In this case, in response to a re-download request, the already transmitted packet is retransmitted, which leads to an increase in the traffic volume of the entire network of the mobile communication system 1 and deteriorates the communication efficiency. For example, when access is concentrated on one of the data servers 200 'and congestion occurs, the packet transmission efficiency deteriorates and the above-described data retransmission is likely to occur.

  FIG. 13 shows an outline of packet transmission when congestion occurs. In the example of FIG. 13A, the packet transmitted from the data server 200'c to the user C is congested. As a result, congestion occurs and the transmission of the packet c by the data server 200'c is interrupted, and a part of the content packet from the data server 200'c does not arrive at the eNB 100 '. At this time, the eNB 100 ′ that incorporates the received packets into the radio frame in the order of reception performs scheduling to incorporate the packet c from the arrived data server 200′c into the radio frame even when the subsequent packet does not reach due to congestion. .

  Thereafter, due to the influence of congestion, not all the packets c from the data server 200'c reach the UE 300'c, so that retransmission occurs in the packet c. At this time, the data server 200'c transmits the already transmitted packet c again. The eNB 100 ′ that has received the retransmission packet c ′ at this time performs scheduling for incorporating the retransmission packet c ′ into the radio frame. For this reason, for example, when the packet b from the data server 200′b that arrives at the eNB 100 ′ later than the retransmission packet c ′ is not incorporated in the radio frame but transmitted in the next radio frame, the content in the UE 200′b Reception is delayed.

  According to the eNB 100, which is a specific example of the disclosed base station, when a packet is received from the data server 200, the transmission schedule of packets to the wireless section is determined in real time based on the communication state of each data server 200 in a predetermined period. Perform the process to change in.

  For this reason, eNB 100, for example, when there is a long response time in a specific data server 200, such as when congestion occurs, for some packets transmitted from the specific data server 200 to the eNB 100, The transmission order is delayed by lowering the transmission priority to the section. Further, the priority of the data size of the transmitted packet, in other words, the packet from the data server 200 with a small signal reception amount is similarly lowered to delay the transmission order. For such a packet, it is considered that the period until the transmission of all packets enabling the user to use the content is relatively long. For example, the eNB 100 delays the transmission order by temporarily storing these packets in a buffer without incorporating them into the radio frames in the order of reception.

  On the other hand, a packet from the data server 200 with a short response time and a packet with a large signal reception amount from the data server 200 are preferentially incorporated into the radio frame. About these packets, it can be said that the period until transmission of all the packets in which the user can use the content is relatively short.

  Thus, a packet with a relatively short response time from the data server 200 or a packet with a large signal reception amount from the data server 200 has priority over a packet with a relatively long response time or a packet with a small signal reception amount. It is transmitted to the radio section. Therefore, a part of the packet that is supposed to have a relatively long period until the transmission of all packets is relatively long is incorporated in the radio frame, so that the packet whose period is relatively short is included in the radio frame. It is not incorporated, and a decrease in efficiency such as transmission delay can be suppressed. As a result, with respect to the content for which the period until transmission of all packets is completed is relatively short, the time from the download request until the content becomes available is shortened. This leads to an improvement in service in that the user who requests the content has a better communication experience. For content that takes a relatively long time to complete transmission of all packets, only the transmission order of some packets that may be wasted due to, for example, congestion or communication delay is delayed. Therefore, it does not lead to a delay in time until transmission of all packets is completed. For this reason, it is possible to enjoy the above-described advantages without prolonging the time from the download request until the content becomes available for content that has a relatively long period until transmission of all packets is completed. .

  In the example described above, the priority determination unit 155 of the eNB 100 determines the priority for determining the packet transmission schedule for each user for each QoS class. However, for example, the configuration may be such that the priority is determined for the entire content packet of different QoS classes, and the transmission schedule is determined.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification, and a base station accompanying such a change The communication control method and the like are also included in the technical scope of the present invention.

  As mentioned above, the following additional remarks are further described about embodiment described in this specification.

(Appendix 1)
A base station connected to a data server via a core network and performing data communication between the data server and one or more mobile terminals located in a subordinate radio section;
Measuring means for measuring a communication state for the one or more mobile terminals in the core network;
A base station comprising: priority determination means for determining communication priority for each of the one or more mobile terminals based on the communication state.

(Appendix 2)
The appendix 1 is characterized in that the measuring unit measures at least one of a signal amount and a response time of data transmitted from the data server to each of the one or more mobile terminals in the core network. The listed base station.

(Appendix 3)
The base station according to appendix 1 or 2, wherein the priority determination unit updates the priority at a predetermined cycle.

(Appendix 4)
The said priority determination means determines the said priority among the said some mobile terminal which belongs to the same QoS (Quality of Service) class, The additional statement 1 to 3 characterized by the above-mentioned. base station.

(Appendix 5)
Storage means for temporarily storing data transmitted from the data server to the one or more mobile terminals;
The base station according to any one of appendices 1 to 4, further comprising: a scheduling unit that determines a transmission order of the data stored in the storage unit based on the priority.

(Appendix 6)
A base station that is connected to a data server via a wired section and performs data communication between the data server and one or more mobile terminals located in a subordinate wireless section,
Measuring means for measuring a communication state for the one or more mobile terminals in the wired section;
A base station comprising: priority determination means for determining priority of communication in the radio section for each of the one or more mobile terminals based on the communication state.

(Appendix 7)
A communication control method in a base station connected to a data server via a core network and performing data communication between the data server and one or more mobile terminals located in a subordinate radio section,
A measuring step of measuring a communication state for the one or more mobile terminals in the core network;
A priority determination step of determining a priority of communication for the one or more mobile terminals based on the communication state.

(Appendix 8)
A communication control method in a base station that is connected to a data server via a wired section and performs data communication between the data server and one or more mobile terminals located in a subordinate wireless section,
A measuring step of measuring a communication state for the one or more mobile terminals in the wired section;
A priority determination step of determining a priority of communication in the radio section for the one or more mobile terminals based on the communication state.

100 eNB (eNODE B),
130 BB processing unit,
150 signal processing unit,
151 signal control unit,
152 measuring unit,
153 priority management database,
154 scheduling section,
155 priority determination unit,
156 Radio transmit buffer,
157 radio receive buffer,
158 Send buffer for wire,
159 Wired receive buffer,
200a-d data server,
300a-c Mobile terminal (UE).

Claims (6)

A base station connected to a data server via a core network and performing data communication between the data server and one or more mobile terminals located in a subordinate radio section;
Measuring means for measuring a communication state for the one or more mobile terminals in the core network;
A base station comprising: priority determination means for determining communication priority for each of the one or more mobile terminals based on the communication state.   2. The measurement means measures at least one of a signal amount and a response time of data transmitted from the data server to each of the one or more mobile terminals in the core network. Base station described in.   The base station according to claim 1 or 2, wherein the priority determination unit updates the priority at a predetermined cycle.   4. The priority determination unit according to claim 1, wherein the priority determination unit determines the priority among the plurality of mobile terminals belonging to the same QoS (Quality of Service) class. 5. Base station. Storage means for temporarily storing data transmitted from the data server to the one or more mobile terminals;
The base station according to any one of claims 1 to 4, further comprising scheduling means for determining a transmission order of the data stored in the storage means based on the priority. A communication control method in a base station connected to a data server via a core network and performing data communication between the data server and one or more mobile terminals located in a subordinate radio section,
A measuring step of measuring a communication state for the one or more mobile terminals in the core network;
A priority determination step of determining a priority of communication for the one or more mobile terminals based on the communication state.

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