JP6139166B2 - Mobile communication system - Google Patents

Description

  The present invention relates to a mobile communication system.

  In Release-10 of LTE (Long Term Evolution), as shown in FIG. 11A, in order to realize broadband communication exceeding 20 MHz (for example, communication at 100 Hz), a plurality of subordinates under the same radio base station eNB CA (Carrier Aggregation), that is, “Intra-eNB CA”, which performs communication by bundling CCs (Component Carriers) of each other, has been introduced.

  Thereafter, "Small Cell enhancement" was proposed in LTE Release 12 or later, and communication is performed by bundling CCs (cells) under different radio base stations eNB as one of more flexible network architectures than before. The introduction of “Inter-eNB CA” is being studied (see FIG. 11B).

  For example, using “Inter-eNB CA”, as shown in FIG. 11 (b), for a C-plane signal that requires reliability, the radio base station eNB # 1 is controlled via an SRB (Signaling Radio Bearer). Cell # 1 (macro cell) and U-plane signals that require broadband communication are communicated via cell # 11 (small cell) under radio base station eNB # 11 via DRB (Data Radio Bearer). Operation such as performing

3GPP TS36.300

  FIG. 12A shows a protocol stack necessary for performing “Intra-eNB CA”.

  Here, when “Inter-eNB CA” is performed, a single RLC (Radio Link Control) layer function is used as in the case of performing “Intra-eNB CA” as shown in FIG. And, due to the line delay between the radio base station eNB # 1 and the radio base station eNB # 10, the RLC layer function is changed from the MAC (Media Access Control) layer function of the radio base station eNB # 10 to the optimum TBS ( (Transport Block Size) cannot be obtained dynamically, and there is a problem that the requested delay cannot be satisfied.

  On the other hand, when “Inter-eNB CA” is performed, as shown in FIG. 12C, when an RLC layer function is provided for each cell (CC), an RLC-SN (Sequence Number) of each RLC layer function There was a problem that management and Reordering control became difficult.

  Therefore, the present invention has been made in view of the above-described problems, and the RLC− in the RLC layer function is minimized while minimizing the line delay between the radio base station eNB # 1 and the radio base station eNB # 11. An object of the present invention is to provide a mobile communication system capable of facilitating SN management and Reordering control.

  A first feature of the present invention is a mobile communication system comprising a first radio base station and a second radio base station, wherein the first radio base station includes a cell under the first radio base station, and the first radio base station. A management unit configured to manage an RLC sequence number used in downlink carrier aggregation for transmitting downlink data to a mobile station via a cell under two radio base stations, and an RLC for the downlink carrier aggregation A generation unit configured to generate an RLC-PDU by assigning a sequence number of the RLC layer to the SDU, and to transmit the generated RLC-PDU to the second radio base station The second radio base station according to radio quality in a cell subordinate to the second radio base station. And a transmitter configured to transmit the RLC-PDU to the mobile station after performing re-segment processing and concatenation processing on the received RLC-PDU. .

  A second feature of the present invention is a mobile communication system including a first radio base station and a second radio base station, wherein the first radio base station includes cells under the first radio base station, the first radio base station, and the first radio base station. A management unit configured to manage an RLC sequence number used in downlink carrier aggregation for transmitting downlink data to a mobile station via a cell under two radio base stations, and an RLC for the downlink carrier aggregation A transmission unit configured to transmit the SDU and the RLC sequence number to the second radio base station, wherein the second radio base station transmits the RLC sequence number to the downlink carrier A generation unit configured to generate an RLC-PDU by giving to an RLC-SDU for aggregation; and a cell under the second radio base station A transmission unit configured to transmit the RLC-PDU to the mobile station after performing segment processing and concatenation processing on the generated RLC-PDU according to radio quality The gist is to provide.

  A third feature of the present invention is a mobile communication system including a first radio base station and a second radio base station, wherein the first radio base station includes a cell under the first radio base station, the first radio base station, and the first radio base station. A management unit configured to manage an RLC sequence number used in downlink carrier aggregation for transmitting downlink data to a mobile station via a cell under two radio base stations; and the downlink carrier aggregation is performed A transmission unit configured to transmit a predetermined number of RLC sequence numbers to the second radio base station, and the second radio base station A generation unit configured to generate an RLC-PDU by assigning one of the RLC sequence numbers to the RLC-SDU for downlink carrier aggregation; and The RLC-PDU is configured to be transmitted to the mobile station after performing segment processing and concatenation processing on the generated RLC-PDU according to radio quality in a cell under the line base station. And a transmitter.

  As described above, according to the present invention, RLC-SN management and Reordering control in the RLC layer function while minimizing the line delay between the radio base station eNB # 1 and the radio base station eNB # 11. It is possible to provide a mobile communication system that can facilitate the above.

1 is an overall configuration diagram of a mobile communication system according to a first embodiment of the present invention. FIG. 3 is a functional block diagram of a radio base station eNB # 1 according to the first embodiment of the present invention. FIG. 3 is a functional block diagram of radio base stations eNB # 11 / # 12 according to the first embodiment of the present invention. It is a figure for demonstrating transmission control of radio base station eNB # 11 / # 12 which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating an example of the transmission method of RLC status report in the mobile communication system which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating an example of the transmission method of RLC status report in the mobile communication system which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating an example of the transmission method of RLC status report in the mobile communication system which concerns on the 1st Embodiment of this invention. It is a sequence which shows operation | movement of radio base station eNB # 1 which concerns on the 1st Embodiment of this invention. It is a whole block diagram of the mobile communication system which concerns on the modification 1 of this invention. It is a whole block diagram of the mobile communication system which concerns on the modification 2 of this invention. 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 radio base station eNB # 1 that manages cell # 1 (not shown) and a radio base station that manages cell # 11 (not shown). eNB # 11 and radio base station eNB # 12 that manages cell # 12 (not shown).

  Here, the cell # 11 and the cell # 12 are small cells (phantom cells), and the cell # 1 is a macro cell. Note that the coverage areas of the cells # 11 and # 12 and the coverage area of the coverage area of the cell # 1 are arranged so as to overlap at least partially.

  In addition, radio base station eNB # 1 may be called a macro radio base station (Macro-eNB), and radio base station eNB # 11 / # 12 is a small radio base station (Small-eNB) or a phantom radio base. It may be called a station (Phantom-eNB).

  The mobile communication system according to the present embodiment is an LTE mobile communication system, and in the mobile communication system according to the present embodiment, the mobile station UE can perform “Inter-eNB CA”. It is configured.

  That is, in the mobile communication system according to the present embodiment, the mobile station UE transmits the cell # 1 under the radio base station eNB # 1 and the cell # 11 / # 12 under the radio base station eNB # 11 / # 12. “Inter-eNB CA” can be performed.

  In the mobile communication system according to the present embodiment, as illustrated in FIG. 1, the radio base station eNB # 1 is configured to function as an anchor radio base station (Anchor-eNB), and the “Master-RLC layer function” Is provided.

  On the other hand, the radio base stations eNB # 11 / # 12 have a “Slave-RLC layer function”.

  That is, in the mobile communication system according to the present embodiment, the RLC layer function is defined as “Master-RLC layer function” and “Slave-RLC layer function” as the radio base station eNB # 1 and the radio base station eNB # 11 / # 12. It is comprised so that it may be distributed and arranged.

  As illustrated in FIG. 2, the radio base station eNB # 1 includes a management unit 11, a reception unit 12, a generation unit 13, and a transmission unit 14 as “Master-RLC layer functions”.

  The management unit 11 is configured to manage the RLC-SN used in “Inter-eNB CA” by the mobile station UE described above.

  The receiving unit 12 is configured to receive the RLC-SDU (Service Data Unit) for the “Inter-eNB CA” from the PDCP (Packet Data Convergence Protocol) layer function.

  The receiving unit 12 may be configured to receive “RLC status report” transmitted by the mobile station UE.

  The generation unit 13 is configured to generate an RLC-PDU by adding the RLC-SN issued by the management unit 11 to the RLC-SDU received by the reception unit 12.

  The transmission unit 14 transmits the RLC-PDU generated by the generation unit 13 and the identifier of the corresponding bearer (or RLC-PDU) to the “Slave-RLC layer function” of the radio base station eNB # 11 / # 12. It is configured as follows.

  Specifically, the transmission unit 14 is configured to generate such RLC-PDU assuming a predetermined TBS.

  Here, the transmission unit 14 may be configured to estimate a predetermined TBS based on the radio quality in the cell # 11 / # 12 under the radio base station eNB # 11 / # 12. Such radio quality may be an averaged value or an instantaneous value.

  Further, the transmission unit 14 determines the “Slave-RLC layer function” of the radio base station eNB # 11 / # 12 based on the actual radio quality in the cell # 11 / # 12 under the radio base station eNB # 11 / # 12. May be configured to determine the number of RLC-PDUs to be transmitted.

  The transmission unit 14 is configured to perform Reordering control on the RLC-PDU generated by the generation unit 13.

  As illustrated in FIG. 3, the radio base stations eNB # 11 / # 12 include a reception unit 21 and a transmission unit 22 as “Slave-RLC layer functions”.

  The receiving unit 21 is configured to receive the RLC-PDU transmitted by the “Master-RLC layer function” of the radio base station eNB # 1.

The transmission unit 22 performs the re-segment processing and the concatenation processing on the RLC-PDU received by the reception unit 21 according to the radio quality in the cell under the radio base station eNB # 11 / # 12, and then performs such RLC -It is configured to transmit the PDU to the mobile station UE (specifically, the MAC layer function).
Specifically, the transmission unit 22 may be configured to determine the TBS according to the actual radio quality in the cell under the radio base station eNB # 11 / # 12.

  Here, when the RLC-PDU received by the receiving unit 21 is smaller than the determined TBS, as illustrated in FIG. 4A, the transmitting unit 22 transmits the RLC-PDU to the MAC layer transport. The entire block is stored. Note that if the size of the RLC-PDU is smaller than the transport block, the surplus portion may be padded.

  Further, when the RLC-PDU received by the receiving unit 21 is larger than the determined TBS, the transmitting unit 22 performs re-segment processing (re-processing on the RLC-PDU as shown in FIG. 4B). -segment), and then stored in the transport block of the MAC layer.

  Further, the transmission unit 22 has attempted to store a plurality of RLC-PDUs in one MAC layer transport block, but stores a part of the plurality of RLC-PDUs in the MAC layer transport block. If it is not possible, as shown in FIG. 4 (c), the RLC-PDU is re-segmented and then stored in the transport block of the MAC layer.

  When receiving RLC-PDU from a plurality of bearers, the transmission unit 22 may be configured to perform transmission (MAC-PDU conversion) to the mobile station UE based on a predetermined priority. Such a predetermined priority may be notified from the “Master-RLC layer function”.

  In addition, as shown in FIG. 5, the mobile station UE transmits the RLC transmitted by the radio base station eNB # 11 / # 12 to both the radio base station eNB # 1 and the radio base station eNB # 11 / # 12. -It may be configured to send "RLC status report" for the PDU.

  Here, each of the radio base station eNB # 1 and the radio base stations eNB # 11 / # 12 may be configured to autonomously perform the RLC retransmission process.

  Alternatively, as illustrated in FIG. 6, the mobile station UE transmits “RLC status report” for the RLC-PDU transmitted by the radio base station eNB # 11 / # 12 to the radio base station eNB # 1. The transmission unit 14 of the radio base station eNB # 1 is configured to transfer the “RLC status report (ACK / NACK information)” to the radio base station eNB # 11 / # 12. It may be.

  Here, the transmission unit 14 of the radio base station eNB # 1 may be configured to transmit the RLC-PDU for which “NACK” is transmitted to the radio base station eNB # 11 / # 12 again. Good.

  Alternatively, the RLC retransmission process for the RLC-PDU to which “NACK” is transmitted may be configured to be performed by the transmission unit 14 of the radio base station eNB # 1, or a radio that manages a cell with good radio quality It may be configured to be performed by the base station eNB.

  Thus, when the RLC retransmission process is performed by the radio base station eNB different from the radio base station eNB # 11 / # 12 that performed the initial transmission (or the previous transmission), the radio base station eNB The radio base station eNB # 11 / # 12 that has performed the initial transmission (or the previous transmission) may be configured to notify that the retransmission of the RLC-PDU has been performed.

  Alternatively, as shown in FIG. 7, the mobile station UE is configured to transmit “RLC status report” to an arbitrary radio base station eNB (for example, Small-eNB). The base station (for example, Small-eNB) is configured to transfer the “RLC status report (ACK / NACK information)” to the radio base station eNB # 1, and the radio base station eNB # 1 The transmission unit 14 may be configured to forward such “RLC status report (ACK / NACK information)” to the radio base stations eNB # 11 / # 12.

  Here, the radio base stations eNB # 11 / # 12 are configured to perform RLC retransmission processing on the RLC-PDU in which “NACK” is transmitted.

  Hereinafter, with reference to FIG. 8, the operation of the mobile communication system according to the present embodiment, specifically, the RLC layer function (“Master-RLC layer function”) of the radio base station eNB # 1 according to the embodiment. The operation will be described.

  As shown in FIG. 8, in step S101, the RLC layer function of the radio base station eNB # 1 determines whether or not the RLC-SDU received from the PDCP layer function should be directly transmitted to the mobile station UE. .

  If “YES”, the operation proceeds to step S102, and if “NO”, the operation proceeds to step S103.

  In step S102, the RLC layer function of the radio base station eNB # 1 generates an RLC-PDU based on the TBS acquired from the MAC layer function and transmits the RLC-PDU to the MAC layer function.

  In step S103, the RLC layer function of the radio base station eNB # 1 generates an RLC-PDU based on the TBS estimated based on the radio quality in the cell under the radio base station eNB # 11 / # 12, thereby generating the radio base station It transmits to the RLC layer function (“Slave-RLC layer function”) of the eNB # 11 / # 12.

(Modification 1)
Hereinafter, with reference to FIG. 9, the mobile communication system according to the first modification of the present invention will be described focusing on the differences from the mobile communication system according to the first embodiment described above.

  In the mobile communication system according to the first modification, the transmission unit 14 of the radio base station eNB # 1 performs the RLC-SDU and RLC-SN and the corresponding bearer (or RLC-PDU) for the “Inter-eNB CA” described above. ) Is transmitted to the radio base stations eNB # 11 / # 12.

  That is, in the mobile communication system according to the first modification, the generation unit 13 of the radio base station eNB # 1 does not generate the RLC-PDU, and the transmission unit 14 of the radio base station eNB # 1 The received RLC-SDU and the RLC-SN delivered by the management unit 11 are configured to transmit to the “Slave-RLC layer function” of the radio base stations eNB # 11 / # 12.

  Note that the management unit 11 of the radio base station eNB # 1 may be provided in a higher layer (for example, PDCP layer) function.

  Further, as shown in FIG. 3, the radio base stations eNB # 11 / # 12 are configured to include a generation unit 23 in addition to the reception unit 21 and the transmission unit 22.

  Here, the generation unit 23 is configured to generate the RLC-PDU by adding the RLC-SN received by the reception unit 21 to the RLC-SDU received by the reception unit 21.

  Further, the transmission unit 22 of the radio base station eNB # 11 / # 12 performs segmentation on the RLC-PDU generated by the generation unit 23 according to the radio quality in the cell under the radio base station eNB # 11 / # 12. After performing the processing, the RLC-PDU is configured to be transmitted to the mobile station UE.

  When receiving RLC-PDU from a plurality of bearers, the transmission unit 22 may be configured to perform transmission (MAC-PDU conversion) to the mobile station UE based on a predetermined priority. Such a predetermined priority may be notified from the “Master-RLC layer function”.

(Modification 2)
Hereinafter, the mobile communication system according to the second modification of the present invention will be described with reference to FIG. 10 while focusing on differences from the mobile communication system according to the first embodiment described above.

  In the mobile communication system according to the second modification, when the above-described “Inter-eNB CA” is performed, the transmission unit 14 of the radio base station eNB # 1 transmits the radio base station eNB # 11 / # 12 to the radio base station eNB # 11 / # 12. Thus, a predetermined number of RLC-SNs are transmitted in advance.

  And the production | generation part 13 of radio base station eNB # 1 does not produce | generate RLC-PDU, The transmission part 14 of radio base station eNB # 1 is radio base station about RLC-SDU received by the receiving part 12. It is comprised so that it may transmit with respect to "Slave-RLC layer function" of eNB # 11 / # 12.

  Note that the transmitter 14 of the radio base station eNB # 1 is configured to adjust a predetermined number of RLC-SNs to be allocated to the radio base stations eNB # 11 / # 12 based on a predetermined criterion. Also good.

  Further, as shown in FIG. 3, the radio base stations eNB # 11 / # 12 are configured to include a generation unit 23 in addition to the reception unit 21 and the transmission unit 22.

  Here, the generation unit 23 pays out one of the predetermined number of RLC-SNs received by the reception unit 21 and assigns it to the RLC-SDU received by the reception unit 21 to generate an RLC-PDU. It is configured.

  Further, the transmission unit 22 of the radio base station eNB # 11 / # 12 performs segmentation on the RLC-PDU generated by the generation unit 23 according to the radio quality in the cell under the radio base station eNB # 11 / # 12. After performing the processing, the RLC-PDU is configured to be transmitted to the mobile station UE.

  In addition, when there is no RLC-SDU for the “Inter-eNB CA” to be transmitted, the transmission unit 22 of the radio base station eNB # 11 / # 12 informs the “Master” of the radio base station eNB # 1. -RLC layer function "may be notified.

  For example, the transmission unit 22 of the radio base station eNB # 11 / # 12 may be configured when there is no RLC-SDU for the “Inter-eNB CA” to be transmitted or when the cell is under the radio base station eNB # 11 / # 12. When the radio quality in # 11 / # 12 is below a predetermined threshold, the RLC-SN allocated to the radio base station eNB # 11 / # 12 may be allocated to another radio base station eNB.

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

  A first feature of the present embodiment is a mobile communication system including a radio base station eNB # 1 (first radio base station) and radio base stations eNB # 11 / # 12 (second radio base station), The radio base station eNB # 1 transmits downlink data to the mobile station UE via a cell under the radio base station eNB # 1 and a cell under the radio base station eNB # 11 / # 12. The management unit 11 configured to manage the RLC-SN (RLC sequence number) used in “downlink carrier aggregation”, and the RLC-SN for the RLC-SDU for the “Inter-eNB CA” A generation unit 13 configured to generate an RLC-PDU by granting the generated RLC-PDU and an identifier of the corresponding bearer (or RLC-PDU) to the radio base and the radio base station eNB # 11 / # 12 is configured to transmit to a cell under the radio base station eNB # 11 / # 12. Depending on the quality, the RLC-PDU received from the radio base station eNB # 1 is re-segmented and concatenated, and then the RLC-PDU is transmitted to the mobile station UE. The gist is that the transmitter 22 is provided.

  According to this feature, since the radio base station eNB # 1 and the radio base stations eNB # 11 / # 12 can take on the role of the RLC layer function in a distributed manner, the radio base station eNB # 1 and the radio base station eNB RLC-SN management and Reordering control can be facilitated while minimizing line delay with # 11 / # 12.

  A second feature of the present embodiment is a mobile communication system including a radio base station eNB # 1 and a radio base station eNB # 11 / # 12. The radio base station eNB # 1 is a radio base station eNB # 1. It is configured to manage the RLC-SN used in “Inter-eNB CA” that transmits downlink data to the mobile station UE via the subordinate cell and the cell under the radio base station eNB # 11 / # 12. And the identifier of the RLC-SDU and RLC-SN for the “Inter-eNB CA” and the corresponding bearer (or RLC-PDU) are transmitted to the radio base station eNB # 11 / # 12. And the radio base station eNB # 11 / # 12 generates the RLC-PDU by adding the RLC-SN to the RLC-SDU for the CA. After performing segment processing and concatenation processing on the generated RLC-PDU according to the radio quality in the cell under the control of the generation unit 23 and the radio base stations eNB # 11 / # 12 The gist of the present invention is to include a transmitter 22 configured to transmit an RLC-PDU to the mobile station UE.

  According to this feature, since the radio base station eNB # 1 and the radio base stations eNB # 11 / # 12 can take on the role of the RLC layer function in a distributed manner, the radio base station eNB # 1 and the radio base station eNB RLC-SN management and Reordering control can be facilitated while minimizing line delay with # 11 / # 12.

  A third feature of the present embodiment is a mobile communication system including a radio base station eNB # 1 and radio base stations eNB # 11 / # 12, and the radio base station eNB # 1 is a radio base station eNB # 1. It is configured to manage the RLC-SN used in “Inter-eNB CA” that transmits downlink data to the mobile station UE via the subordinate cell and the cell under the radio base station eNB # 11 / # 12. Configured to transmit in advance a predetermined number of RLC-SNs to the radio base stations eNB # 11 / # 12 when such an “Inter-eNB CA” is performed. The radio base station eNB # 11 / # 12 assigns one of a predetermined number of RLC-SNs to the RLC-SDU for the “Inter-eNB CA”, and transmits the RLC- Generate PDU After performing segment processing and concatenation processing on the generated RLC-PDU according to the radio quality in the cell under the control of the generation unit 23 and the radio base stations eNB # 11 / # 12 The gist of the present invention is to include a transmitter 22 configured to transmit an RLC-PDU to the mobile station UE.

  According to this feature, since the radio base station eNB # 1 and the radio base stations eNB # 11 / # 12 can take on the role of the RLC layer function in a distributed manner, the radio base station eNB # 1 and the radio base station eNB RLC-SN management and Reordering control can be facilitated while minimizing line delay with # 11 / # 12.

  In the third feature of the present embodiment, when there is no RLC-SDU for the “Inter-eNB CA” to be transmitted, the transmission unit 22 notifies the radio base station eNB # 1 to that effect. It may be configured as follows.

  According to this feature, the radio base station eNB # 1 can allocate the RLC-SN allocated to the radio base station eNB # 11 / # 12 to another radio base station eNB based on the notification. -Can effectively use SN resources.

  In the first to third features of the present embodiment, the mobile station UE transmits “RLC status report (RLC status report)” to the radio base station eNB # 1 and the radio base station eNB # 11 / # 12. It may be configured to.

  According to this feature, even when “Inter-eNB CA” is performed, “RLC status” is transmitted to the radio base stations eNB # 11 / # 12 that have transmitted the RLC-PDU to the mobile station UE. report ".

  In the first to third features of the present embodiment, the mobile station UE is configured to transmit “RLC status report” to the radio base station eNB # 1, and the radio base station eNB # 1 The “RLC status report” may be transferred to the radio base stations eNB # 11 / # 12.

  According to this feature, even when “Inter-eNB CA” is performed, “RLC status” is transmitted to the radio base stations eNB # 11 / # 12 that have transmitted the RLC-PDU to the mobile station UE. report ".

  In the first to third characteristics of the present embodiment, the mobile station UE is configured to transmit “RLC status report” to an arbitrary radio base station eNB, and the arbitrary radio base station The radio base station eNB # 1 is configured to transfer the “RLC status report”, and the radio base station eNB # 1 is configured to transfer the radio base station eNB # 1 to the radio base station eNB # 11 / # 12. It may be configured to forward “RLC status report”.

  According to this feature, even when “Inter-eNB CA” is performed, “RLC status” is transmitted to the radio base stations eNB # 11 / # 12 that have transmitted the RLC-PDU to the mobile station UE. report ".

  Also, the radio base station eNB that should transmit “RLC status report” may be designated from any radio base station (for example, radio base station eNB # 1) to the mobile station UE.

Such designation notification may be performed in any layer of the RRC layer, the PDCP layer, the RLC layer, the MAC layer, and the physical layer. Alternatively, the designation notification may be transmitted in the cell that has received the (new) “UL grant” for the first time after determining to transmit “RLC status report” to the radio base station eNB.

  In the above-described example, it is mentioned that the “Master-RLC layer function” is installed in the radio base station eNB # 1, but the radio base station eNB in which the “Master-RLC layer function” is set for each bearer. May be different.

  Note that the operations of the mobile station UE and the radio base stations eNB # 1 / eNB # 11 / eNB # 12 described above may be implemented by hardware or may be implemented by a software module executed by a processor. , Or a combination of both.

  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 or the radio base station eNB # 1 / eNB # 11 / eNB # 12. Further, the storage medium and the processor may be provided in the mobile station UE and the radio base stations eNB # 1 / eNB # 11 / eNB # 12 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.

eNB # 1, eNB # 11, eNB # 12 ... radio base station UE ... mobile station 11 ... management unit 12, 21 ... reception unit 13, 23 ... generation unit 14, 22 ... transmission unit

Claims (7)

A mobile communication system comprising a first radio base station and a second radio base station,
The first radio base station is
It is configured to manage RLC sequence numbers used in downlink carrier aggregation for transmitting downlink data to a mobile station via a cell under the first radio base station and a cell under the second radio base station. A management department,
A generation unit configured to generate an RLC-PDU by applying the RL C sequence number against the RLC-SDU for the downlink carrier aggregation,
A transmission unit configured to transmit the generated RLC-PDU and bearer or the identifier of the RLC-PDU to the second radio base station;
The second radio base station is
Depending on the radio quality in the cell under the second radio base station, the RLC-PDU received from the first radio base station is re-segmented and concatenated, and then the RLC-PDU is moved. A mobile communication system comprising a transmission unit configured to transmit to a station. A mobile communication system comprising a first radio base station and a second radio base station,
The first radio base station is
It is configured to manage RLC sequence numbers used in downlink carrier aggregation for transmitting downlink data to a mobile station via a cell under the first radio base station and a cell under the second radio base station. A management department,
A transmitter configured to transmit the RLC-SDU for downlink carrier aggregation, the RLC sequence number and the bearer or the identifier of the RLC-PDU to the second radio base station; ,
The second radio base station is
A generation unit configured to generate the RLC-PDU by assigning the RLC sequence number to the RLC-SDU for downlink carrier aggregation;
The RLC-PDU is transmitted to the mobile station after performing segment processing and concatenation processing on the generated RLC-PDU according to radio quality in a cell under the second radio base station. A mobile communication system comprising a transmitter configured as described above. A mobile communication system comprising a first radio base station and a second radio base station,
The first radio base station is
It is configured to manage RLC sequence numbers used in downlink carrier aggregation for transmitting downlink data to a mobile station via a cell under the first radio base station and a cell under the second radio base station. A management department,
A transmitter configured to transmit a predetermined number of RLC sequence numbers and bearers or identifiers of the RLC-PDUs in advance to the second radio base station when the downlink carrier aggregation is performed. And
The second radio base station is
A generating unit configured to give one of the predetermined number of RLC sequence numbers to the RLC-SDU for downlink carrier aggregation to generate an RLC-PDU;
The RLC-PDU is transmitted to the mobile station after performing segment processing and concatenation processing on the generated RLC-PDU according to radio quality in a cell under the second radio base station. And a transmitter configured as described above.   The transmission unit is configured to notify the first radio base station to that effect when there is no RLC-SDU for downlink carrier aggregation to be transmitted. 4. The mobile communication system according to 3.   5. The mobile station according to claim 1, wherein the mobile station is configured to transmit an RLC status report to the first radio base station and the second radio base station. 6. The mobile communication system described. The mobile station is configured to transmit an RLC status report to the first radio base station;
5. The movement according to claim 1, wherein the first radio base station is configured to transfer the RLC status report to the second radio base station. 6. Communications system. The mobile station is configured to send an RLC status report to any radio base station;
The arbitrary radio base station is configured to forward the RLC status report to the first radio base station;
5. The movement according to claim 1, wherein the first radio base station is configured to transfer the RLC status report to the second radio base station. 6. Communications system.

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