JP2014220612A - Radio base station and mobile communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the situation in which TCP layer data exceeding the amount of data that can be processed at one time is transmitted to an upper-layer node.SOLUTION: A radio base station eNB according to the invention comprises: a receiving unit 12 configured to receive TCP layer data from a router 1 and to receive a TCP-ACK from a mobile station UE; and a transmitting unit 13 configured to transmit TCP layer data to the mobile station UE and to transmit a TCP-ACK to the router. The transmitting unit 13 is configured to limit the amount of data of the TCP-ACK to be transmitted to the router at one time to a predetermined amount X or less.

Description

  The present invention relates to a radio base station and a mobile communication method.

  In the TCP (Transmission Control Protocol) layer, the transmission side device receives the next transmission side according to the reception status of the delivery confirmation signal (TCP-ACK) for the TCP packet (TCP layer data) transmitted to the reception side device. It is configured to determine the number of TCP packets to send to the device.

  Specifically, as shown in FIG. 6, in the TCP layer, if the transmission side apparatus can receive the TCP-ACK, it increases the number of TCP packets to be transmitted to the reception side apparatus and receives the TCP-ACK. If not, it is configured to reduce the number of TCP packets to be transmitted next to the receiving apparatus.

  Also, in the RLC (Radio Link Control) layer, window control is performed in order to transmit and receive RLC packets (RLC layer data) in order and without omission.

  In particular, the reception-side apparatus is configured to perform order correction control (RLC reordering control) and duplicate discard control in the RLC layer.

  Specifically, as illustrated in FIG. 7, in the RLC layer, the transmission side device newly transmits RLC packets having an SN (Sequence Number) included in the transmission side window (Tx window) in order and transmits When there is no untransmitted RLC packet in the side window, the new transmission of the RLC packet is stopped.

  Here, the transmission side apparatus is configured to update the transmission side window based on “Status report (ACK)” received from the reception side apparatus.

  On the other hand, as shown in FIG. 7, in the RLC layer, the receiving side device manages the receiving side window (Rx window), and only receives the RLC packet (RLC-PDU) having the SN included in the receiving side window. It is configured to store in the reception buffer and discard other RLC packets (RLC-PDU).

  Here, if there is a missing SN, the receiving side device does not update the receiving side window. If the receiving side device succeeds in receiving the RLC packet (RLC-PDU) having the missing SN, the receiving side window is not updated. Configured to update.

3GPP TS36.322 v10.0

  Currently, the LTE (Long Term Evolution) radio base station eNB, as shown in FIGS. 8 and 9, is unaware of the amount of data (bandwidth) that can be processed at once in the router 1 as an upper node. The TCP-ACK received from the mobile station UE is configured to be transmitted to the router 1 at a time.

  For example, as illustrated in FIG. 8, the radio base station eNB does not receive the RLC packet # 0 including the TCP-ACK for the TCP packet of SN # 0 in the RLC layer. The RLC packets # 1 to # 4 including the TCP-ACK for the TCP packets of .about. # 4 are buffered.

  After that, as illustrated in FIG. 9, when the radio base station eNB succeeds in receiving the RLC packet # 0 including the TCP-ACK for the TCP packet of SN # 0 in the RLC layer, the radio base station eNB TCP-ACK for the # 4 TCP packet is sent to the router 1 at a time.

  Here, as shown in FIG. 10, the TCP server 2 receives TCP-ACK for the TCP packets of SN # 0 to # 4 all at once, and therefore sends a large amount of TCP packets to the router 1.

  As a result, when the router 1 receives a TCP packet that exceeds the amount of data that can be processed at once, the TCP packet that exceeds the amount of data is discarded.

  Therefore, the present invention has been made in view of the above-described problems, and it is possible to avoid a situation in which TCP layer data exceeding the amount of data that can be processed at one time is transmitted to an upper node. An object of the present invention is to provide a wireless base station and a mobile communication method that can be used.

  A first feature of the present invention is a radio base station, which is configured to receive TCP layer data from an upper node, and to receive a delivery confirmation signal for the TCP layer data from a mobile station And a transmission unit configured to transmit the TCP layer data to the mobile station and transmit the delivery confirmation signal to the upper node, and the transmission unit includes: The gist is that the amount of data of the delivery confirmation signal transmitted to the upper node at a time is limited to a predetermined amount or less.

  A second feature of the present invention is a mobile communication method, in which a higher-level node transmits TCP layer data to a radio base station, and the radio base station A step B of transmitting the TCP layer data; a step C in which the mobile station transmits an acknowledgment signal for the TCP layer data to the radio base station; and the radio base station In contrast, the step D of transmitting the delivery confirmation signal and the step of determining the data amount of the TCP layer to be transmitted to the radio base station by the upper node according to the reception status of the delivery confirmation signal The wireless base station limits the data amount of the delivery confirmation signal transmitted to the upper node at a time to a predetermined amount or less in the step D.

  A third feature of the present invention is a radio base station, which is configured to receive TCP layer data from a mobile station and to receive a delivery confirmation signal for the TCP layer data from an upper node. And a transmission unit configured to transmit the TCP layer data to the upper node and transmit the delivery confirmation signal to the mobile station, and the transmission unit includes: The gist is that the data amount of the delivery confirmation signal transmitted to the mobile station at a time is limited to a predetermined amount or less.

  A fourth feature of the present invention is a radio base station, which is configured to receive TCP layer data from a mobile station and to receive a delivery confirmation signal for the TCP layer data from an upper node. And a transmission unit configured to transmit the TCP layer data to the upper node and transmit the delivery confirmation signal to the mobile station, and the transmission unit includes: The gist is that the amount of data of the TCP layer transmitted to the upper node at a time is limited to a predetermined amount or less.

  As described above, according to the present invention, it is possible to avoid a situation in which TCP layer data exceeding the amount of data that can be processed at one time is transmitted to an upper node and a mobile base station that can avoid the situation A communication method can be provided.

It is a figure for demonstrating the whole structure and operation | movement of the mobile communication system which concerns on the 1st Embodiment of this invention. FIG. 3 is a functional block diagram of a radio base station eNB according to the first embodiment of the present invention. It is a figure for demonstrating the whole structure and operation | movement of the mobile communication system which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the whole structure and operation | movement of the mobile communication system which concerns on the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the radio base station eNB which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating a prior art. It is a figure for demonstrating a prior art. It is a figure for demonstrating a prior art. It is a figure for demonstrating a prior art. It is a figure for demonstrating a prior art.

(Mobile communication system according to the first embodiment of the present invention)
A mobile communication system according to a first embodiment of the present invention will be described with reference to FIG. 1 to FIG.

  As shown in FIG. 1, the mobile communication system according to the present embodiment includes a mobile station UE, a radio base station eNB, a router 1, and a TCP server 2.

  The mobile station UE and the radio base station eNB according to the present embodiment may be configured to perform order correction control and overlap cancellation control in the RLC layer.

  As illustrated in FIG. 2, the radio base station eNB according to the present embodiment includes a calculation unit 11, a reception unit 12, and a transmission unit 13.

  The calculation unit 11 is configured to calculate a predetermined amount X that defines the amount of TCP-ACK data to be transmitted to the router 1 at a time.

  For example, the calculation unit 11 may be configured to calculate the predetermined amount X based on the average size (average DL IP packet size) of IP packets in the downlink.

  Alternatively, the calculation unit 11 is configured to calculate the predetermined amount X based on the maximum value of the total value of TCP layer data (TCP packet / TCP segment) received by the reception unit 12 within a predetermined time. May be.

  Note that the calculation unit 11 may be configured to periodically update the predetermined amount X. Moreover, when a plurality of data flows (Data flow) or bearers (Bearers) are set, the predetermined amount X may be configured to be set for each data flow or bearer.

  The receiving unit 12 is configured to receive a TCP packet from the router 1 and receive a TCP-ACK from the mobile station UE.

  The transmission unit 13 is configured to transmit a TCP packet to the mobile station UE and transmit a TCP-ACK to the router.

  The transmission unit 13 is configured to limit the amount of TCP-ACK data transmitted to the router 1 at a time to a predetermined amount X or less.

  Here, the predetermined amount X may be defined by the number of TCP-ACKs, or may be defined by a data amount itself such as a byte amount or a bit amount.

  The transmission unit 13 may be configured to buffer TCP-ACK exceeding a predetermined amount X and transmit the buffered TCP-ACK to the router 1 after a predetermined period.

  Hereinafter, the operation of the mobile communication system according to the present embodiment will be described with reference to FIGS. 1 and 3 to 5.

  First, with reference to FIG. 1, FIG. 3, and FIG. 4, an operation when a TCP packet is transmitted by the TCP server 2 in the mobile communication system according to the present embodiment will be described.

  As illustrated in FIG. 1, the radio base station eNB receives the TCP packets of SN # 0 to # 4 transmitted by the TCP server 2 via the router 1 in step S101, and The TCP packets of SN # 0 to # 4 are transmitted.

  In step S102, the mobile station UE transmits RLC packets # 0 to # 4 including TCP-ACK for the TCP packets of SN # 0 to # 4 to the radio base station eNB.

  In the example of FIG. 1, the mobile station UE fails to transmit the RLC packet # 0 including TCP-ACK for the TCP packet of SN # 0, and retransmits the RLC packet # 0.

  In step S103, since the radio base station eNB has not received the RLC packet # 0 including the TCP-ACK for the TCP packet of SN # 0 in the RLC layer, the TCP of SN # 1 to # 4 is controlled by the order correction control. RLC packets # 1 to # 4 including TCP-ACK for the packet are buffered.

  After that, as illustrated in FIG. 3, when the radio base station eNB succeeds in receiving the RLC packet # 0 including the TCP-ACK for the TCP packet of SN # 0 in the RLC layer, in step S104, in the TCP layer, TCP-ACKs for the TCP packets of SN # 0 to # 2 are transmitted to the router 1 at a time, and in step S105, a predetermined amount X (data amount corresponding to three TCP-ACKs in the example of FIG. 3) is exceeded. Buffering is continued for TCP-ACK (or RLC packets # 3 to # 4 including such TCP-ACK) for the SN # 3 to # 4 TCP packets.

  Here, as shown in FIG. 4, since the TCP server 2 has received the TCP-ACK for the TCP packets of SN # 0 to # 2, the number of TCP packets to be transmitted next to the receiving side device is “4”. In step S106, a TCP packet having SN # 5 to # 8 is transmitted to the router 1.

  For example, in the present embodiment, since the amount of data (number of TCP packets) that can be processed at once in the router 1 is “4”, the router 1 discards TCP packets having SN # 5 to # 8. Can be processed without any problems.

  After that, in step S106, the radio base station eNB transmits TCP-ACK to the router 1 for the buffered SN # 3- # 4 TCP packets after a predetermined period has elapsed.

  2ndly, with reference to FIG. 5, operation | movement of the radio base station eNB which concerns on this embodiment is demonstrated.

  As shown in FIG. 5, in step S101, the radio base station eNB determines whether or not the amount of TCP-ACK data to be transmitted to the router 1 next is smaller than a predetermined amount X. .

  In the case of “Yes”, the operation proceeds to step S102, and in the case of “No”, the operation proceeds to step S103.

  In step S103, the radio base station eNB transmits all buffered TCP-ACKs to the router 1.

  On the other hand, in step S104, the radio base station eNB transmits to the router 1 a TCP-ACK having a data amount equal to or smaller than a predetermined amount X among all buffered TCP-ACKs, and the remaining TCP-ACKs Continue buffering for.

(Modification 1)
Hereinafter, the mobile communication system according to the first modification of the present invention will be described by focusing on the differences from the mobile communication system according to the first embodiment described above.

  The mobile communication system according to the first modification regulates TCP packets transmitted in the uplink.

  Specifically, the reception unit 12 of the radio base station eNB is configured to receive a TCP packet from the mobile station UE and receive a TCP-ACK from the router 1, and the transmission unit 13 of the radio base station eNB The TCP packet is transmitted to the router 1 and the TCP-ACK is transmitted to the mobile station UE.

  And the transmission part 13 is comprised so that the data amount of TCP-ACK transmitted with respect to the mobile station UE at once may be restrict | limited to the predetermined amount X or less.

  Hereinafter, the operation when the mobile station UE transmits a TCP packet in the mobile communication system according to the first modification will be described.

  First, the radio base station eNB determines the location based on the amount of TCP packet data (or the number of TCP packets) that can be received at once by the router 1 and the average size of IP packets in the uplink (average UL IP packet size). Quantitative X is calculated. Note that the radio base station eNB may periodically update the predetermined amount X.

  First, the radio base station eNB receives the TCP packet transmitted by the mobile station UE, and transmits the TCP packet to the router 1.

  Secondly, the TCP server 2 transmits a TCP-ACK for the received TCP packet to the radio base station eNB via the router 1.

  Third, when the data amount of the received TCP-ACK is smaller than the predetermined amount X, the radio base station eNB transmits all of the TCP-ACK to the mobile station UE at a time.

  On the other hand, when the data amount of the received TCP-ACK is larger than the predetermined amount X, the radio base station eNB transmits a TCP-ACK having a data amount equal to or smaller than the predetermined amount X to the mobile station UE at a time. TCP-ACK exceeding X (or RLC packet including such TCP-ACK) is buffered.

  As a result, since the mobile station UE has received a TCP-ACK equal to or less than the predetermined amount X, the number of TCP packets to be transmitted next to the receiving side device is increased, but the number of such packets is received at the router 1 at a time. It is adjusted so as not to exceed the data amount of possible TCP packets.

  Thereafter, the radio base station eNB transmits the buffered TCP-ACK to the mobile station UE after a predetermined period has elapsed.

(Modification 2)
Hereinafter, the mobile communication system according to the second modification of the present invention will be described by focusing on differences from the above-described first embodiment and the mobile communication system according to the first modification.

  The mobile communication system according to the second modification stipulates TCP packets transmitted in the uplink.

  The transmission unit 13 of the radio base station eNB according to the second modification is configured not to limit the amount of TCP-ACK data transmitted to the mobile station UE at a time.

  On the other hand, the transmission unit 13 is configured to limit the data amount of TCP packets transmitted to the router 1 at a time to a predetermined amount X or less.

  Here, the transmission unit 13 buffers TCP packets (or RLC packets including TCP packets) exceeding a predetermined amount X, and transmits the buffered TCP packets to the router 1 after a predetermined period has elapsed. It may be configured to.

  When the reception unit 12 receives a TCP-ACK from the router 1, the transmission unit 13 increases the number of TCP packets to be transmitted next to the reception side device so as not to exceed the predetermined amount X. It may be configured.

  The characteristics of the present embodiment described above may be expressed as follows.

  The first feature of the present embodiment is a radio base station eNB, which receives TCP layer data from the router 1 (upper node), and receives TCP-ACK (delivery confirmation signal for TCP layer data) from the mobile station UE. And a transmission unit 13 configured to transmit TCP layer data to the mobile station UE and transmit TCP-ACK to the router. Thus, the gist of the transmission unit 13 is that the amount of TCP-ACK data transmitted to the router 1 at a time is limited to a predetermined amount X or less.

  According to this feature, in the radio base station eNB, by limiting the amount of TCP-ACK data transmitted to the router 1 at a time to a predetermined amount X or less, the TCP server 2 The number of TCP packets to be transmitted can be adjusted so as not to exceed the amount of data that can be processed at once in the router 1.

  In the first feature of the present embodiment, the transmission unit 13 buffers TCP-ACK exceeding a predetermined amount X, and transmits the buffered TCP-ACK to the router 1 after a predetermined period has elapsed. It may be configured.

  According to such a feature, in the radio base station eNB, TCP packets exceeding the amount of data that can be processed at one time by the TCP server 2 with respect to the router 1 are discarded without discarding TCP-ACK exceeding the predetermined amount X. The situation of transmitting can be avoided.

  In the first feature of the present embodiment, the calculation unit 11 may be further configured to calculate the predetermined amount X based on the average size of the IP packet in the downlink.

  According to this feature, an appropriate predetermined amount X can be calculated based on the average size of IP packets transmitted from the TCP server 2 to the router 1.

  In the first feature of the present embodiment, the calculation unit 11 is configured to calculate the predetermined amount X based on the maximum value of the total value of the data of the TCP layer received by the reception unit 12 within a predetermined time. May further be provided.

  According to this feature, an appropriate predetermined amount X can be calculated based on the maximum value of the total value of TCP packets transmitted from the TCP server 2 to the router 1 within a predetermined time.

  In the first feature of the present embodiment, the predetermined amount X may be configured to be set for each data flow or bearer.

  According to this feature, an appropriate predetermined amount X can be calculated according to the transmission state of TCP packets in each data flow or each bearer.

  The second feature of the present embodiment is a mobile communication method, in which the router 1 transmits TCP layer data to the radio base station eNB, and the radio base station eNB transmits to the mobile station UE. On the other hand, the process B for transmitting TCP layer data, the process C for the mobile station UE to transmit TCP-ACK to the radio base station eNB, and the radio base station eNB to the router 1 A step D for transmitting ACK, and a step E in which the router 1 determines the data amount of the TCP layer to be transmitted to the radio base station eNB according to the reception status of the TCP-ACK. The gist of the process D is that the radio base station eNB limits the data amount of TCP-ACK transmitted to the router 1 at a time to a predetermined amount X or less.

  According to this feature, in the radio base station eNB, by limiting the amount of TCP-ACK data transmitted to the router 1 at a time to a predetermined amount X or less, the TCP server 2 The number of TCP packets to be transmitted can be adjusted so as not to exceed the amount of data that can be processed at once in the router 1.

  A third feature of the present embodiment is a radio base station eNB, which is configured to receive TCP layer data from the mobile station UE and receive TCP-ACK from the router 1, A transmission unit 13 configured to transmit TCP layer data to the router 1 and transmit TCP-ACK to the mobile station UE. The gist is that the data amount of TCP-ACK transmitted to the UE is limited to a predetermined amount or less.

  According to such a feature, in the radio base station eNB, by limiting the amount of TCP-ACK data to be transmitted to the mobile station UE at a time to a predetermined amount X or less, in the mobile station UE, the radio base station eNB It is possible to adjust the number of TCP packets to be transmitted so as not to exceed the amount of data that can be processed at once in the router 1.

  A fourth feature of the present embodiment is a radio base station eNB, which is configured to receive TCP layer data from the mobile station UE and receive TCP-ACK from the router 1, A transmission unit 13 configured to transmit TCP layer data to the router 1 and transmit TCP-ACK to the mobile station UE. The gist is that the data amount of the TCP layer to be transmitted is limited to a predetermined amount or less.

  According to this feature, in the radio base station eNB, by limiting the data amount of TCP packets transmitted to the router 1 at a time to a predetermined amount X or less, the radio base station eNB next The number of TCP packets to be transmitted can be adjusted so as not to exceed the amount of data that can be processed at once in the router 1.

  The operations of the mobile station UE, the radio base station eNB, the router 1 and the TCP server 2 described above may be implemented by hardware, a software module executed by a processor, It may be implemented by a combination.

  The software module includes a RAM (Random Access Memory), a flash memory, a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electronically Erasable and Programmable ROM, a hard disk, a registerable ROM, a hard disk). Alternatively, it may be provided in a storage medium of an arbitrary format such as a CD-ROM.

  Such a storage medium is connected to the processor so that the processor can read and write information from and to the storage medium. Further, such a storage medium may be integrated in the processor. Such a storage medium and processor may be provided in the ASIC. Such an ASIC may be provided in the mobile station UE, the radio base station eNB, the router 1, or the TCP server 2. Further, the storage medium and the processor may be provided in the mobile station UE, the radio base station eNB, the router 1 or the TCP server 2 as discrete components.

  Although the present invention has been described in detail using the above-described embodiments, it is obvious to those skilled in the art that the present invention is not limited to the embodiments described in this specification. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

DESCRIPTION OF SYMBOLS 1 ... Router 2 ... TCP server eNB ... Wireless base station UE ... Mobile station 11 ... Calculation part 12 ... Reception part 13 ... Transmission part

Claims (8)

A wireless base station,
A receiving unit configured to receive TCP layer data from an upper node and receive a delivery confirmation signal for the TCP layer data from a mobile station;
A transmission unit configured to transmit the TCP layer data to the mobile station and transmit the delivery confirmation signal to the upper node;
The radio base station, wherein the transmission unit is configured to limit a data amount of the delivery confirmation signal transmitted to the upper node at a time to a predetermined amount or less.   The transmission unit is configured to buffer the delivery confirmation signal exceeding the predetermined amount and transmit the buffered delivery confirmation signal to the upper node after a predetermined period of time. The radio base station according to claim 1.   The radio base station according to claim 1 or 2, further comprising a calculation unit configured to calculate the predetermined amount based on an average size of IP packets in a downlink.   The apparatus further comprises a calculation unit configured to calculate the predetermined amount based on a maximum value of a total value of the TCP layer data received by the reception unit within a predetermined time. The radio base station according to claim 1 or 2.   The radio base station according to any one of claims 1 to 4, wherein the predetermined amount is configured to be set for each data flow or bearer. Step A in which the upper node transmits TCP layer data to the radio base station;
Step B in which the radio base station transmits the TCP layer data to the mobile station;
The mobile station transmitting a delivery confirmation signal for the data of the TCP layer to the radio base station;
Step D in which the radio base station transmits the delivery confirmation signal to the upper node;
The upper node includes a step E of determining a data amount of a TCP layer to be transmitted to the radio base station according to the reception status of the delivery confirmation signal,
In the step D, the radio base station limits the data amount of the delivery confirmation signal transmitted to the upper node at a time to a predetermined amount or less. A wireless base station,
A receiving unit configured to receive TCP layer data from a mobile station and receive an acknowledgment signal for the TCP layer data from an upper node;
A transmission unit configured to transmit the TCP layer data to the upper node and transmit the delivery confirmation signal to the mobile station;
The radio base station, wherein the transmission unit is configured to limit a data amount of the delivery confirmation signal transmitted to the mobile station at a time to a predetermined amount or less. A wireless base station,
A receiving unit configured to receive TCP layer data from a mobile station and receive an acknowledgment signal for the TCP layer data from an upper node;
A transmission unit configured to transmit the TCP layer data to the upper node and transmit the delivery confirmation signal to the mobile station;
The radio base station, wherein the transmission unit is configured to limit a data amount of the TCP layer transmitted to the upper node at a time to a predetermined amount or less.

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