JP6043549B2 - Mobile station - Google Patents

Description

  The present invention relates to a mobile station.

  In Release-10 of LTE (Long Term Evolution), as shown in FIG. 5A, 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 performs communication by bundling CCs (Component Carriers) is 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-site CA” is being studied (see FIG. 5B).

3GPP 36.300

  As shown in FIG. 6, the conventional LTE scheme is configured to associate one EPS (Evolved Packet System) bearer with one radio bearer.

  Specifically, as illustrated in FIG. 6, the EPS bearer includes one radio bearer, one S1 bearer, and one S5 / S8 bearer.

  Here, the radio bearer is set between the mobile station UE and the radio base station eNB, the S1 bearer is set between the radio base station eNB and the gateway device S-GW, and S5 / S8. The bearer is set between the gateway device S-GW and the gateway device P-GW.

  That is, the EPS bearer is a bearer set between the mobile station UE and the gateway device P-GW.

  Here, in order to realize “Inter-site CA”, it is assumed that a “Bearer Sharing” function for associating one EPS bearer with a plurality of radio bearers is required.

  As described above, since the existing mobile station UE does not have the “Bearer Sharing” function, in order to realize “Inter-site CA”, the “Bearer Sharing” is performed for the mobile station UE. It was necessary to provide a function.

  However, the existing LTE scheme has a problem that the mobile station UE having such a “Bearer Sharing” function cannot be specified on the network (radio base station eNB) side.

  Therefore, the present invention has been made in view of the above-described problems, and realizes “Inter-site CA” by notifying the network whether or not the “Bearer Sharing” function is provided. An object of the present invention is to provide a mobile station that can perform communication.

  A first feature of the present invention is a mobile station, which transmits capability information indicating whether or not carrier aggregation can be performed to a radio base station via cells under a plurality of radio base stations. The gist of the invention is to provide a transmitter configured as described above.

  As described above, according to the present invention, it is possible to provide a mobile station capable of realizing “Inter-site CA” by notifying the network whether or not the “Bearer Sharing” function is provided. can do.

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 mobile station according to the first embodiment of the present invention. FIG. 3 is a functional block diagram of a radio base station according to the first embodiment of the present invention. FIG. 3 is a sequence diagram showing an operation of the mobile communication system according to the first embodiment of the present 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 FIGS.

  The mobile communication system according to the present embodiment is an LTE mobile communication system, and is configured to be able to apply “Inter-site CA”.

  As shown in FIG. 1, the mobile communication system according to the present embodiment includes a gateway device P-GW, a gateway device S-GW, and radio base stations eNB # 1 to # 3.

  For example, the cell # 1 under the radio base station eNB # 1 is a macro cell, and the cells # 2 through # 3 under the radio base stations eNB # 2 to # 3 are phantom cells (small cells).

  In addition, it is assumed that the coverage areas of the cells # 1 to # 3 under the radio base stations eNB # 1 to # 3 are arranged to overlap at least partially.

  The mobile communication system according to the present embodiment is configured to be able to apply “Bearer Sharing” that associates one EPS bearer with a plurality of radio bearers.

  Here, in the example of FIG. 1, among the radio base stations eNB # 1 to # 3, the radio base station eNB # 1 is the anchor radio base station eNB, and for the mobile station UE, one EPS bearer and a plurality of The radio bearers # 1 to # 3 are configured to be associated with each other.

  Note that the anchor radio base station eNB may be the radio base station eNB # 1 that manages the macro cell, or may be another radio base station eNB. Also, in the mobile communication system according to the present embodiment or in a predetermined area in the mobile communication system according to the present embodiment, only one anchor radio base station eNB exists for each mobile station UE. There may be more than one.

  As illustrated in FIG. 2, the mobile station UE according to the present embodiment includes a reception unit 11, a management unit 12, and a transmission unit 13.

  The reception unit 11 is configured to receive various signals from the radio base stations eNB # 1 to # 3, and the transmission unit 13 transmits various signals to the radio base stations eNB # 1 to # 3. It is configured.

  Also, the management unit 12 manages whether or not the mobile station UE has a “Bearer Sharing” function, that is, whether or not the mobile station UE can realize “Inter-site CA”. It is configured.

  For example, the receiving unit 11 is configured to receive “UE Capability Enquiry” from the radio base station eNB # 1 functioning as the anchor radio base station eNB.

  Further, the transmission unit 13 indicates whether or not the mobile station UE can perform “Inter-site CA” to the radio base station eNB # 1 in response to the “UE Capability Enquiry”. The mobile station UE is configured to transmit “Bearer Sharing Capability” indicating whether or not the “Bearer Sharing” function is provided.

  Note that the transmission unit 13 may be configured to notify “Bearer Sharing Capability” together with “CA Capability”.

  Specifically, the transmission unit 13 may be configured to notify about “Bearer Sharing Capability” using the same “Information element” as that of “CA Capability”.

  In addition, the transmission unit 13 sets “Bearer Sharing Capability” to the number of radio base stations eNB (or the number of cells) that the mobile station UE can perform “Inter-site CA”, that is, “Bearer Sharing” at the same time. May be configured to notify the number of radio base stations eNB (or the number of cells) that can be performed.

  Further, the transmission unit 13 may be configured to notify about “Bearer Sharing Capability” in each of the uplink and the downlink.

  Further, the transmission unit 13 may be configured to notify “Bearer Sharing Capability” for each frequency supported by the mobile station UE.

  The transmission unit 13 may be configured to notify “Bearer Sharing Capability” for each “CA band combination” supported by the mobile station UE.

  Moreover, the transmission part 13 may be comprised so that it may notify about "Bearer Sharing Capability" for every functional part like RF of the mobile station UE.

  In “Bearer Sharing”, a plurality of PDCP (Packet Data Convergence Protocol) entities can be broadly classified into “Master PDCP” and “Slave PDCP”.

  In such a case, it is conceivable that the “Master PDCP” bears a part of the function of the “Slave PDCP”.

  Furthermore, in “Inter-site CA”, the mobile station UE communicates with a plurality of radio base stations eNB, but the radio base station eNB is classified as a macro radio base station eNB or a small radio base station eNB. In this case, the transmission unit 13 may be configured to notify “Bearer Sharing Capability” for each type of the radio base station eNB.

  Further, when there are a plurality of anchor radio base stations eNB in “Bearer Sharing”, the transmission unit 13 may be configured to notify the number of configurable anchor radio base stations eNB as “Bearer Sharing Capability”. .

  Furthermore, “Bearer Sharing Capability” may be associated with “UE category” of the mobile station UE.

  As illustrated in FIG. 3, the radio base station eNB # 1 includes a transmission unit 21, a reception unit 22, a management unit 23, and a control unit 24.

  The transmission unit 21 is configured to transmit various signals to the mobile station UE, and the reception unit 22 is configured to receive various signals from the mobile station UE.

  For example, the transmission unit 21 is configured to transmit “UE Capability Enquiry” to the mobile station UE.

  The receiving unit 22 is configured to receive the above-mentioned “Bearer Sharing Capability”, “CA Capability”, and the like from the mobile station UE.

  Based on the “Bearer Sharing Capability” received by the receiver 22, the management unit 23 determines whether or not the mobile station UE has the “Bearer Sharing” function, that is, the mobile station UE performs “Inter-site CA”. It is configured to manage whether or not it can be realized.

  The control unit 24 is configured to perform various controls in the mobile station UE.

  For example, the control unit 24 performs “Inter-site CA” on the mobile station UE having the “Bearer Sharing” function, that is, the mobile station UE capable of realizing “Inter-site CA”. Is configured to determine that.

  Here, when the control unit 24 determines that the control unit 24 performs “Inter-site CA” on the specific mobile station UE, the transmission unit 21 is a radio base station eNB other than the anchor radio base station eNB. A “Bearer sharing request” is transmitted to a small radio base station eNB (for example, the radio base station eNB # 2), and information for performing the “Bearer sharing” is transmitted to the specific mobile station UE. An “RRC connection reconfiguration” is included.

  In addition, the transmission part 21 may be comprised so that this information may be notified with respect to the mobile station UE by separate signaling.

  Here, even if the transmission unit 21 is configured to notify the mobile station UE of such information by RRC (Radio Resource Control) message, for example, by “RRC connection reconfiguration” or the like as individual signaling. Good.

  The mobile station UE is configured to perform “Bearer sharing” using such information.

  As a result, in the example of FIG. 1, in the uplink, the data of the radio bearer # 1 is transmitted from the mobile station UE to the radio base station eNB # 1 via the cell # 1 under the radio base station eNB # 1. It is configured as follows.

  In the example of FIG. 1, in the uplink, the data of the radio bearer # 2 is transmitted from the mobile station UE to the radio base station eNB # 1 via the cell # 2 under the radio base station eNB # 2. It is configured.

  Further, in the example of FIG. 1, in uplink, the data of the radio bearer # 3 is transmitted from the mobile station UE to the radio base station eNB # 1 via the cell # 3 under the radio base station eNB # 3. It is configured.

  Similarly, in the example of FIG. 1, in the downlink, the data of the radio bearer # 1 is transmitted from the radio base station eNB # 1 to the mobile station UE via the cell # 1 under the radio base station eNB # 1. It is configured as follows.

  In the example of FIG. 1, the data of the radio bearer # 2 is transmitted from the radio base station eNB # 2 to the mobile station UE via the cell # 2 under the radio base station eNB # 2 in the downlink. It is configured.

  Furthermore, in the example of FIG. 1, in the downlink, the data of the radio bearer # 3 is transmitted from the radio base station eNB # 3 to the mobile station UE via the cell # 3 under the radio base station eNB # 3. It is configured.

  Here, the radio bearer # 2 may be configured to terminate between the mobile station UE and the radio base station eNB # 2, or the mobile station UE and the radio base station via the radio base station eNB # 2 It may be configured to terminate with the station eNB # 1.

  Similarly, the radio bearer # 3 may be configured to terminate between the mobile station UE and the radio base station eNB # 3, or the mobile station UE and the radio base station via the radio base station eNB # 3. It may be configured to terminate with the station eNB # 1.

  Note that the transmission unit 21 of the radio base station eNB # 1 functioning as the anchor radio base station eNB uses the data addressed to the mobile station UE received via the S1 bearer in the downlink for the cells # 1 to # 3. And is transmitted to the mobile station UE via the radio bearers # 1 to # 3.

  In addition, the reception unit 22 of the radio base station eNB # 1 functioning as the anchor radio base station eNB uses the data for the cells # 1 to # 3 received via the radio bearers # 1 to # 3 in the uplink. The transmission unit 21 is configured to transmit the data to the S1 bearer by performing a reordering process.

  On the other hand, the receiving unit 11 of the mobile station UE is configured to perform an order correction process on the data for the cells # 1 to # 3 received via the radio bearers # 1 to # 3 in the downlink. .

  In addition, the transmission unit 13 of the mobile station UE divides data to be transmitted into data for the cells # 1 to # 3 in the uplink, and the radio base station eNB via the radio bearers # 1 to # 3. It is configured to transmit to # 1 to # 3.

  Hereinafter, the operation of the mobile communication system according to the present embodiment will be described with reference to FIG. Specifically, with reference to FIG. 4, an operation when starting “Bearer Sharing” in the mobile communication system according to the present embodiment will be described.

  As illustrated in FIG. 4, in step S1001, the radio base station eNB # 1 that manages the cell # 1 that is a macro cell transmits “UE Capability” to the mobile station UE that is in the “RRC_Connected state” in the cell # 1. “Enquiry” is transmitted.

  In step S1002, the mobile station UE transmits the above-mentioned “Bearer Sharing Capability” to the radio base station eNB # 1 in response to the “UE Capability Enquiry” to the radio base station eNB # 1.

  Thereafter, in step S1011, the mobile station UE transmits “Measurement report” indicating that the quality of the cell # 2, which is a small cell, has improved to the radio base station eNB # 1.

  In step S1012, the radio base station eNB # 1 transmits “Bearer sharing request” to the radio base station eNB # 2 in response to the “Measurement report”.

  In step S1013, when the radio base station eNB # 2 determines that “Bearer Sharing” can be started in response to the “Bearer sharing request”, the radio base station eNB # 2 performs “Bearer sharing” for the radio base station eNB # 1. request ACK ".

  In step S1014, the radio base station eNB # 1 makes one EPS bearer, radio bearer # 1 / # 2, and radio base station eNB # 1 / # 2 (or cell # 1 / # 2) for the mobile station UE. ), Ie, “RRC connection reconfiguration” including information for performing “Bearer sharing” is transmitted.

  In step S1015, the mobile station UE performs the above-described association according to “RRC connection reconfiguration” and transmits “RRC connection reconfiguration complete” to the radio base station eNB # 1.

  In step S1016, the radio base station eNB # 1 transmits “Bearer sharing complete” to the radio base station eNB # 2, and in step S1017, the data addressed to the mobile station UE to the radio base station eNB # 2 Transfer of (U-plane data) is started.

  As a result, in step S1018, the U-plane path communicates between the mobile station UE and the radio base station eNB # 2, that is, “Bearer Sharing” is started.

  Even when “Bearer Sharing” is started, the path of the C-plane remains between the mobile station UE and the radio base station eNB # 1.

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

  The first feature of the present embodiment is a mobile station UE, which is connected to the radio base station eNB # 1 via cells # 1 / # 2 subordinate to a plurality of radio base stations eNB # 1 / # 2. The gist is to include a transmission unit 13 configured to transmit “Bearer Sharing Capability” indicating whether or not “Inter-site CA (Carrier Aggregation)” can be performed.

  According to such a configuration, whether or not the mobile station UE can perform “Inter-site CA” for the radio base station eNB # 1 by “Bearer Sharing Capability”, that is, “Bearer Sharing”. Since it is possible to notify whether or not the function is provided, the radio base station eNB # 1 instructs the mobile station UE having the “Bearer Sharing” function to perform “Inter-site CA” only. be able to.

  In the first feature of the present embodiment, the transmission unit 13 may be configured to notify the number of radio base stations eNB that can perform “Inter-site CA” as “Bearer Sharing Capability”. .

  According to this configuration, the radio base station eNB # 1 can instruct the mobile station UE to perform “Inter-site CA” via an appropriate number of cells under the radio base station eNB. .

  In the first feature of the present embodiment, the transmission unit 13 may be configured to notify “Bearer Sharing Capability” in each of the uplink and the downlink.

  In the first feature of the present embodiment, the transmission unit 13 may be configured to notify “Bearer Sharing Capability” for each frequency supported by the mobile station UE.

  In the first feature of the present embodiment, the transmission unit 13 may be configured to notify “Bearer Sharing Capability” for each “CA band combination (carrier combination)” supported by the mobile station UE. Good.

  In the first feature of the present embodiment, the transmission unit 13 may be configured to notify the “Bearer Sharing Capability” for each RF (radio function unit) of the mobile station UE.

  1st characteristic of this embodiment WHEREIN: The transmission part 13 may be comprised so that it may notify about "Bearer Sharing Capability" for every classification | category of the radio base station eNB which the mobile station UE communicates.

  Note that the operations of the mobile station UE and the radio base stations eNB # 1 / # 2 / # 3 described above may be implemented by hardware, software modules executed by a processor, or both It may be implemented by a combination of

  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 / # 2 / # 3. Further, the storage medium and the processor may be provided in the mobile station UE and the radio base stations eNB # 1 / # 2 / # 3 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 # 2, eNB # 3 ... radio base station UE ... mobile station 11, 22 ... receiving unit 12, 23 ... managing unit 13, 21 ... transmitting unit 24 ... control unit

Claims (7)

One bearer set between a mobile station and a gateway device as capability information indicating whether or not carrier aggregation can be performed via a cell under a plurality of radio base stations for a radio base station ; A transmission unit configured to transmit capability information indicating whether or not a Bearer Sharing function for associating a plurality of radio bearers set between the mobile station and a plurality of radio base stations is provided. A mobile station comprising: The mobile station according to claim 1, wherein the transmission unit is configured to notify the number of radio base stations capable of performing Bearer Sharing simultaneously as the capability information.   The mobile station according to claim 1 or 2, wherein the transmission unit is configured to notify the capability information in each of an uplink and a downlink.   The mobile station according to any one of claims 1 to 3, wherein the transmitting unit is configured to notify the capability information for each frequency supported by the mobile station.   The mobile station according to any one of claims 1 to 3, wherein the transmitting unit is configured to notify the capability information for each carrier combination supported by the mobile station. .   4. The mobile station according to claim 1, wherein the transmission unit is configured to notify the capability information for each radio function unit of the mobile station. 5.   The mobile unit according to any one of claims 1 to 3, wherein the transmission unit is configured to notify the capability information for each type of radio base station with which the mobile station communicates. Bureau.

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