JP2019047510A - User device, base station, and communication method - Google Patents

Abstract

To provide a technique capable of changing a length of a sequence number of an RLC PDU while preventing throughput deterioration.SOLUTION: A user device for communicating with a base station includes: reception means for receiving an instruction to change a sequence number length of an RLC PDU from the base station; re-establishment means for performing re-establishment processing of an RLC entity when the instruction is received; and communication means for communicating with the base station using the RLC PDU with the sequence number length changed after completion of the re-establishment processing. The instruction includes an instruction to change the RLC PDU sequence length to 11 bits or more when a secondary cell is added or deleted.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a user apparatus, a base station and a communication method.

  In LTE (Long Term Evolution) systems, carrier aggregation (CA: Carrier Aggregation) is employed in which communication is performed using a plurality of carriers simultaneously with a predetermined bandwidth (up to 20 MHz) as a basic unit. A carrier that is a basic unit in carrier aggregation is called a component carrier (CC: Component Carrier).

  When CA is performed, PCell (Primary Cell: primary cell), which is a highly reliable cell for securing connectivity, and SCell (secondary cell: secondary cell), which is an accompanying cell, are provided to the user apparatus. It is set. The user apparatus can first connect to the PCell and add SCells as needed. The PCell is a cell similar to a single cell supporting RLM (Radio Link Monitoring), SPS (Semi-Persistent Scheduling), and the like.

  SCell is a cell added to PCell and set with respect to a user apparatus. Addition and deletion of SCells are performed by RRC (Radio Resource Control) signaling. Since SCell is in an inactive state (deactivate state) immediately after being set for the user apparatus, SCell is a cell that can be communicated (scheduled) only after activation.

  Further, in the LTE system, RLC (Radio Link Control) is used for radio communication performed between the user apparatus and the base station. The RLC can set one of a plurality of transfer modes for each radio bearer. Specifically, RLC-AM (RLC-Acknowledge Mode) in which retransmission control is performed based on a delivery confirmation signal from the receiving side, RLC-UM (RLC-Unacknowledge Mode) in which retransmission control is not performed, and RLC There is TM (Transparent Mode) that transmits itself. The RLC performs communication by exchanging RLC PDUs (Protocol Data Unit) between an RLC entity on the user apparatus side and an RLC entity on the base station side. Also, in RLC-AM and RLC-UM, duplicate detection and reordering of RLC PDUs are performed using a sequence number (SN: Sequence Number) assigned to the header of the RLC PDU. The length of the RLC sequence number is specified to be 10 bits in RLC-AM and 5 bits or 10 bits in RLC-UM (see, for example, Non-Patent Document 1).

3GPP TS 36.322 V12.2.0 (2015-03)

  In the conventional LTE specification, the number of CCs that can be configured per user apparatus is at most 5, while the Rel. In 13 LTEs, in order to realize more flexible and high-speed wireless communication, and to be able to bundle a large number of CCs in a continuous ultra-wideband unlicensed band, the limitation of up to 5 CCs to be bundled in CA is The CA enhancement to be taken is being considered. For example, a CA that bundles up to 32 CCs is under consideration. It is assumed that the peak rate that can be achieved will be dramatically improved by performing CA that bundles up to 32 CCs.

  Here, in RLC, window control is performed to limit the number of RLC PDUs that can be transmitted simultaneously, in order to perform duplication detection and order correction. The window control limits the number of RLC PDUs that can be transmitted simultaneously to half of the maximum sequence number. That is, even if the peak rate is dramatically improved by CA, the window control performed by RLC may become a bottleneck. Therefore, when expanding CCs bundled in CA, it is desirable to simultaneously expand the maximum sequence number of RLC so that the window control performed by RLC does not become a bottleneck. That is, it is desirable to extend the length of the sequence number to 11 bits or more.

  FIG. 1 is a diagram illustrating a conventional RLC PDU format. The RLC PDU format shown in FIG. 1 is a PDU format used in RLC-AM. As shown in FIG. 1, since the length of the sequence number is 10 bits and there is no reserved area, the header part (part excluding Data) is necessary to extend the length of the sequence number to 11 bits or more. The data size of must be increased by 1 octet (1 byte) or more.

  As described above, when the length of the RLC sequence number is changed, the data size of the header part of the RLC PDU is changed. Therefore, when changing the length of the RLC sequence number, it is necessary to perform RLC entity re-establishment processing (RLC re-establishment) in order to delete (reset) the PDU including the short sequence number before the change. .

  In the current LTE system, the RLC entity re-establishment process is performed only when the handover process is performed. In other words, when performing reestablishment processing of the RLC entity while following the processing defined in the current LTE system, handover processing must be performed.

  Further, in the current LTE system, when handover processing is performed, all SCells are changed to a state of being temporarily deactivated. Therefore, after handover processing, all SCells have to be changed to the activated state again, which may cause a decrease in throughput.

  The technology disclosed herein has been made in view of the above, and it is an object of the present invention to provide a technology capable of changing the length of the sequence number of an RLC PDU while suppressing a decrease in throughput.

  The user apparatus according to the disclosed technology is a user apparatus that communicates with a base station, and an accepting unit that accepts an instruction to change the sequence number length of an RLC PDU from the base station; The instruction includes re-establishment means for performing an entity re-establishment process, and communication means for communicating with the base station using an RLC PDU whose sequence number length has been changed after the re-establishment process is completed. And an instruction to change the sequence number length of the RLC PDU to 11 bits or more when adding or deleting a secondary cell.

  According to the disclosed technology, a technology is provided that can change the length of the sequence number of the RLC PDU while suppressing the reduction in throughput.

It is a figure which shows the conventional RLC PDU format. It is a figure which shows the structural example of the mobile communication system which concerns on embodiment. It is a figure which shows an example of a function structure of the base station which concerns on embodiment. It is a figure which shows an example of a function structure of the user apparatus which concerns on embodiment. It is a sequence diagram which shows an example of the process sequence (the 1) which concerns on embodiment. It is a sequence diagram which shows an example of the process sequence (the 2) which concerns on embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are merely examples, and the embodiments to which the present invention is applied are not limited to the following embodiments. For example, although the mobile communication system according to the present embodiment assumes a system based on LTE, the present invention is not limited to LTE, and is applicable to other systems. In the present specification and claims, “LTE” is not only a communication scheme corresponding to Release 8 or 9 of 3GPP, but also a communication scheme corresponding to Release 10, 11, 12, or 13 or later of 3GPP. Use in a broad sense, including.

<Overview>
FIG. 2 is a diagram showing the configuration of the mobile communication system according to the embodiment. As shown in FIG. 2, the mobile communication system in the present embodiment is a mobile communication system including a user apparatus UE and a base station eNB, and performing CA communication between the user apparatus UE and the base station eNB. it can.

  Further, although one cell is shown in the example of FIG. 2, this is also for convenience of illustration, and when CA is set, a plurality of cells exist. Also, for example, the configuration may be such that an RRE connected to the base station eNB with an optical fiber or the like is provided at a location distant from the base station eNB.

  The base station eNB communicates with the user apparatus UE via radio. The base station eNB is a CPU such as a processor, a memory device such as a ROM, a RAM or a flash memory, an antenna for communicating with the user apparatus UE, etc., a communication interface apparatus for communicating with an adjacent base station eNB, core network etc. It consists of the hardware resources of Each function and process of base station eNB may be realized by a processor processing or executing data and programs stored in a memory device. However, the base station eNB is not limited to the above-described hardware configuration, and may have any other appropriate hardware configuration.

  The user apparatus UE has a function of communicating with the base station eNB, the core network, and the like through radio. The user apparatus UE is, for example, a mobile phone, a smartphone, a tablet, a mobile router, a wearable terminal, or the like. The user apparatus UE may be any user apparatus UE as long as the apparatus has a communication function. The user apparatus UE is configured by a CPU such as a processor, a memory device such as a ROM, a RAM, or a flash memory, an antenna for communicating with the base station eNB, and hardware resources such as an RF (Radio Frequency) device. Each function and process of the user apparatus UE may be realized by the processor processing or executing data or program stored in the memory device. However, the user apparatus UE is not limited to the above-described hardware configuration, and may have any other suitable hardware configuration.

  The mobile communication system in the present embodiment, for example, when adding a SCell in CA, extends the length of the sequence number of the RLC PDU in order to improve the peak rate. Also, conversely, when deleting the SCell in the CA, in order to reduce the data size of the RLC PDU, the length of the sequence number of the RLC PDU is shortened. In addition, when changing the length of the sequence number of the RLC PDU, the SCell bundled in the CA is not deactivated.

<Functional configuration>
(base station)
FIG. 3 is a diagram showing an example of a functional configuration of a base station according to the embodiment. As shown in FIG. 3, the base station eNB includes a signal transmission unit 11, a signal reception unit 12, an RRC processing unit 13, an RLC processing unit 14, and a MAC (Media Access Control) processing unit 15. Note that FIG. 3 shows only the functional units that are particularly relevant to the embodiment of the present invention in the base station eNB, and also has at least a function (not shown) for performing operations compliant with LTE. Further, the functional configuration shown in FIG. 3 is merely an example. As long as the operation according to the present embodiment can be performed, the names of the function classifications and the function parts may be arbitrary.

  The signal transmission unit 11 includes a function of generating various signals of the physical layer from the signal of the upper layer to be transmitted from the base station eNB and performing wireless transmission. The signal receiving unit 12 includes a function of wirelessly receiving various signals from the user apparatus UE, and acquiring a higher layer signal from the received physical layer signal.

  The RRC processing unit 13 transmits and receives RRC signals to and from the user apparatus UE, and performs various processes related to the RRC layer. Also, the RRC processing unit 13 has a function of instructing the user apparatus UE to change the length of the sequence number of the RLC PDU, a function of instructing the user apparatus UE to perform handover processing, and adding or deleting a SCell in the user apparatus UE. It has a function to instruct. Also, the RRC processing unit 13 acquires, from the user apparatus UE, information (hereinafter referred to as "capability information") indicating that the user apparatus UE has the ability to change the length of the sequence number of the RLC PDU. Have a function to

  The RLC processing unit 14 transmits and receives RLC PDUs to and from the user apparatus UE, and performs various processes related to the RLC layer. Also, the RLC processing unit 14 performs a reestablishment process (RLC Re-establishment process) of the RLC entity according to an instruction from the RRC processing unit 13, and deletes (resets) the PDU including the short sequence number before the change. Have. Further, the RLC processing unit 14 has a function of transmitting and receiving RLC PDUs using an RLC PDU format capable of storing a sequence number of 11 bits or more.

  The MAC processing unit 15 performs various processes related to the MAC layer. In addition, the MAC processing unit 15 has a function of instructing the user apparatus UE to activate and deactivate SCell.

(User device)
FIG. 4 is a diagram showing an example of a functional configuration of a base station according to the embodiment. As shown in FIG. 4, the user apparatus UE includes a signal transmission unit 21, a signal reception unit 22, an RRC processing unit 23, an RLC processing unit 24, and a MAC processing unit 25. Note that FIG. 4 shows only the functional units that are particularly relevant to the embodiment of the present invention in the user apparatus UE, and also has at least a function (not shown) for performing operations compliant with LTE. Also, the functional configuration shown in FIG. 4 is merely an example. As long as the operation according to the present embodiment can be performed, the names of the function classifications and the function parts may be arbitrary.

  The signal transmission unit 21 includes a function of generating various signals of the physical layer from the signal of the upper layer to be transmitted from the user apparatus UE and performing wireless transmission. The signal reception unit 22 includes a function of wirelessly receiving various signals from the base station eNB, and acquiring a higher layer signal from the received physical layer signal.

  The RRC processing unit 23 transmits and receives an RRC signal to and from the base station eNB, and performs various processes related to the RRC layer. Also, the RRC processing unit 23 has a function of changing the length of the sequence number of the RLC PDU according to an instruction from the base station eNB, a function of performing a handover process according to an instruction from the base station eNB, and an SCell according to an instruction from the base station eNB. Have the function of adding or deleting Also, the RRC processing unit 23 has a function of transmitting capability information to the base station eNB.

  The RLC processing unit 24 transmits and receives RLC PDUs to and from the base station eNB, and performs various processes related to the RLC layer. Also, the RLC processing unit 24 performs an RLC entity reestablishment process (RLC Re-establishment process) according to an instruction from the RRC processing unit 23, and deletes (resets) a PDU including a short sequence number before the change. Have. Further, the RLC processing unit 24 has a function of transmitting and receiving RLC PDUs using an RLC PDU format capable of storing a sequence number of 11 bits or more.

  The MAC processing unit 25 performs various processes related to the MAC layer. In addition, the MAC processing unit 25 has a function of activating and deactivating SCells. In addition, the MAC processing unit 25 has a deactivation timer (Deactivation Timer), and deactivates the SCell if communication is not performed in the SCell for a certain period of time. In addition, the MAC processing unit 25 has a function of not inactivating the SCell as necessary, not necessarily inactivating the SCell when handover processing is performed by the RRC layer.

<Processing procedure>
Hereinafter, the processing procedure when the length of the sequence number of the RLC PDU is changed in the mobile communication system according to the embodiment will be described using the drawings.

(1)
FIG. 5 is a sequence diagram showing an example of a processing procedure (part 1) according to the embodiment. In this procedure (No. 1), reestablishment processing of the RLC entity is performed without performing handover processing.

  In step S101, the RRC processing unit 23 of the user apparatus UE transmits a capability notification signal including capability information to the base station eNB. The RRC processing unit 13 of the base station eNB grasps, based on the capability information, whether or not the user apparatus UE has the capability of changing the length of the sequence number of the RLC PDU. Note that the capability notification signal may be, for example, an RRC signal (for example, UE Capability Information), or may be a MAC signal or a signal of a physical layer. In addition, a specific UE category may be set in advance between the base station eNB and the user apparatus UE, and the specific UE category may be stored in the capability information. In this case, the RRC control unit 13 of the base station eNB grasps whether or not the user apparatus UE has the capability of changing the length of the sequence number of the RLC PDU based on the specific UE category. . Also, the base station eNB has a capability that the user apparatus UE can change the length of the sequence number of the RLC PDU according to the maximum number of CCs that the user apparatus UE can support by CA or the number of MIMOs that can be communicated. It may be grasped whether or not it has.

  In step S102, the RRC control unit 13 of the base station eNB transmits an RRC connection Reconfiguration signal to the user apparatus UE. The RRC connection Reconfiguration signal includes an SCell addition / deletion instruction and information indicating that the length of the sequence number of the RLC PDU should be changed (hereinafter referred to as “sequence number length change instruction”).

  The sequence number length change instruction may be represented by, for example, 2 bits. For example, when making the length of the sequence number the same as the conventional LTE specification, “0” is set in the sequence number length change instruction, and when making the length of the extended sequence number, “1” in the sequence number length change instruction. "May be set. Also, the length of the sequence number may be changed variously by using three or more bits. Also, the sequence number length change instruction may be able to separately indicate the length of the uplink RLC PDU sequence number and the length of the downlink RLC PDU sequence number, or only one of them may be specified. You may be able to indicate.

  In step S103, the signal transmission unit 11, the signal reception unit 12, and the RLC processing unit 14 of the base station eNB temporarily stop transmission and reception of the radio signal in response to the processing procedure of step S102 being performed.

  In step S104, the signal transmission unit 21, the signal reception unit 22, and the RLC processing unit 24 of the user apparatus UE temporarily stop transmission / reception of radio signals in response to the sequence number length change instruction being received in the process procedure of step S102. Do.

  In step S105, the RLC processing unit 14 of the base station eNB performs reestablishment processing of the RLC entity. Also, the RLC processing unit 14 changes the processing method so as to generate an RLC PDU with the length of the sequence number corresponding to the sequence number length change instruction transmitted to the user apparatus UE in step S102. If, in step S102, a sequence number length change instruction in which the length of the uplink RLC PDU sequence number and the length of the downlink RLC PDU sequence number are separately designated is transmitted to the user apparatus UE, The processing unit 14 changes the processing method so as to generate the uplink RLC PDU and the downlink RLC PDU with the length of the indicated sequence number.

  In step S106, the RLC processing unit 24 of the user apparatus UE performs a reestablishment process of the RLC entity. Also, the RLC processing unit 24 changes the processing method so as to generate an RLC PDU with the length of the sequence number corresponding to the sequence number length change instruction instructed from the base station eNB in step S102. When the sequence number length change instruction in which the length of the sequence number of the uplink RLC PDU and the length of the sequence number of the downlink RLC PDU are separately designated is received in step S102, the RLC processing unit 24 receives , And change the processing method so as to generate uplink RLC PDUs and downlink RLC PDUs with the lengths of the indicated sequence numbers, respectively.

  In step S107, the RRC processing unit 23 of the user apparatus UE transmits an RRC connection Reconfiguration complete signal to the base station eNB in order to notify the base station eNB that the RLC entity re-establishment process has been completed.

  In step S108, the signal transmission unit 21, the signal reception unit 22, and the RLC processing unit 24 of the user apparatus UE transmit the RRC connection Reconfiguration complete signal, for example, in the process procedure of step S107. Signal transmission and reception is started using the length RLC PDU.

  In step S109, the signal transmission unit 11, the signal reception unit 12, and the RLC processing unit 14 of the base station eNB perform the processing procedure of step S107, for example, at the timing when the RRC connection Reconfiguration complete signal is received, Signal transmission and reception is started using the length RLC PDU.

(Part 2)
FIG. 6 is a sequence diagram showing an example of a processing procedure (part 2) according to the embodiment. In this processing procedure (part 2), by forcibly performing the handover process, the RLC entity re-establishment process is performed using the conventional LTE function, and the handover is performed by the conventional LTE function. It is made to suppress the deactivation process of SCell that has been performed automatically during the process. The points not particularly mentioned may be the same as those in FIG.

  The processing procedure of step S201 is the same as the processing procedure of step S101 of FIG.

  In step S202, the RRC control unit 13 of the base station eNB transmits an RRC connection Reconfiguration signal to the user apparatus UE. The RRC connection Reconfiguration signal includes an SCell addition / deletion instruction, an Intra-cell HO (Hand Over) instruction, and a sequence number length change instruction.

  The processing procedures of step S203 and step S204 are the same as the processing procedures of step S103 and step S104 of FIG.

  In step S205, the RLC processing unit 14 of the base station eNB performs an intra-cell HO process to perform an RLC entity re-establishment process. Also, the RLC processing unit 14 changes the processing method so as to generate an RLC PDU with the length of the sequence number corresponding to the sequence number length change instruction transmitted to the user apparatus UE in step S202. If, in step S202, a sequence number length change instruction in which the length of the sequence number of the uplink RLC PDU and the length of the sequence number of the downlink RLC PDU are separately designated is transmitted to the user apparatus UE, The processing unit 14 changes the processing method so as to generate the uplink RLC PDU and the downlink RLC PDU with the length of the indicated sequence number.

  In step S206, the RLC processing unit 24 of the user apparatus UE performs an intra-cell HO process to perform an RLC entity re-establishment process. Also, the RLC processing unit 24 changes the processing method so as to generate an RLC PDU with the length of the sequence number corresponding to the sequence number length change instruction instructed from the base station eNB in step S202. When the sequence number length change instruction in which the length of the uplink RLC PDU sequence number and the length of the downlink RLC PDU sequence number are separately designated is received in step S202, the RLC processing unit 24 receives , And change the processing method so as to generate uplink RLC PDUs and downlink RLC PDUs with the lengths of the indicated sequence numbers, respectively.

  Moreover, in the Intra-cell HO process in step S206, the MAC processing unit 25 of the user apparatus UE performs control so as not to deactivate the SCell in the CA. The MAC processing unit 25 may temporarily stop the operation of the deactivation timer (Deactivation Timer) while performing the intra-cell HO process. This makes it possible to prevent the SCell from being deactivated due to the expiration of the timer while performing the Intra-cell HO process.

  Also, the MAC processing unit 25 may detect that the HO process has been completed, and restart the operation of the deactivation timer. Also, the operation of the deactivation timer may be resumed by an instruction from the base station eNB. Further, the MAC processing unit 25 may resume the operation of the deactivation timer when the user apparatus UE receives a PDCCH (Physical Downlink Control Channel).

  In addition, in the processing procedure of step S206, the MAC processing unit 25 of the user apparatus UE may perform control so as not to deactivate only a part of SCells among the SCells in the CA. For example, the MAC processing unit 25 may control not to deactivate only SCells whose CellIndex or SCellIndex is larger (or smaller) than a predetermined value. In addition, when the SCell includes an LAA (License Assisted Access) cell, the MAC processing unit 25 controls not to deactivate only the SCell other than the LAA cell (that is, the cell of the license frequency band). May be The LAA cell means a cell in which the Listen before Talk function is operating or a cell in an unlicensed frequency band.

  The processing procedure of step S207 to step S209 is the same as the processing procedure of step S107 to step S109 of FIG.

<Summary>
As described above, according to the embodiment, the user apparatus that communicates with the base station is an accepting unit that accepts an instruction to change the sequence number length of the RLC PDU from the base station, and the instruction Re-establishment means for performing re-establishment processing of an RLC entity when accepted, and communication means for communicating with the base station using an RLC PDU whose sequence number length has been changed after the re-establishment processing is completed. The user equipment is provided, wherein the instruction includes an instruction to change the sequence number length of the RLC PDU to 11 bits or more when adding or deleting a secondary cell. The user apparatus UE provides a technique capable of changing the length of the sequence number of the RLC PDU while suppressing the decrease in throughput.

  Further, the instruction includes an instruction to change the sequence number length of the RLC PDU in uplink and an instruction to change at least one of the sequence number length of the RLC PDU in downlink, and the communication unit is configured to change the RLC in uplink. When an instruction to change the sequence number length of the PDU is received, an instruction to change the sequence number length of the RLC PDU in the downlink by communicating with the base station using the RLC PDU in the uplink in which the sequence number length has been changed is given. If received, the base station may be communicated using the RLC PDU in downlink for which the sequence number length has been changed. With this configuration, when the uplink peak rate and the downlink peak rate are different, for example, only the downlink RLC PDU can change the length of the sequence number. As a result, it is possible to suppress an increase in the amount of data in the entire communication that accompanies an increase in the size of the header part of the RLC PDU.

  Further, the base station may further comprise notifying means for notifying that the user apparatus has the ability to change the sequence number length of the RLC PDU. With this configuration, the user apparatus UE can cause the base station eNB to change the length of the RLC PDU sequence number only when the user apparatus UE has the ability to change the length of the RLC PDU sequence number. become.

  Further, the instruction further includes an instruction indicating that the handover process is to be performed, and the re-establishing unit performs the handover process when the instruction to perform the handover process is received, thereby performing the RLC process. An entity re-establishment process may be performed. This configuration makes it possible to perform RLC entity re-establishment processing while diverting the conventional LTE function.

  In addition, when the communication means receives an instruction to perform the handover process and an instruction to change the sequence number length of the RLC PDU, the communication means performs the handover process without deactivating the secondary cell. It is also good. With this configuration, the base station eNB and the user apparatus UE do not need to perform processing for reactivating the SCell, and it is possible to suppress a decrease in throughput.

  Further, the communication unit may stop the deactivation timer while performing the handover process without deactivating the secondary cell. With this configuration, it is possible to prevent the SCell from being deactivated by expiration of the timer while performing the Intra-cell HO process.

  Further, according to the present embodiment, in the case of a base station that communicates with a user apparatus, the transmitting apparatus transmits to the user apparatus an instruction to change the sequence number length of the RLC PDU, and the instruction is transmitted And reestablishing means for reestablishing the RLC entity, and communication means for communicating with the user apparatus using the RLC PDU whose sequence number length has been changed after the reestablishment process is completed, The instruction may provide a base station including an instruction to change a sequence number length of an RLC PDU to 11 bits or more when adding or deleting a secondary cell. The base station eNB provides a technique capable of changing the length of the sequence number of the RLC PDU while suppressing the decrease in throughput.

  Further, according to the present embodiment, in the communication method in the mobile communication system having the base station and the user apparatus, the base station transmits, to the user apparatus, an instruction to change the sequence number length of the RLC PDU. , The user apparatus receives the instruction from the base station, the base station performs an RLC entity reestablishment process, and the user apparatus performs an RLC entity reestablishment process Communicating with the user equipment using the RLC PDU with a changed sequence number length after the base station completes the RLC entity re-establishment process; the user equipment re-establishes the RLC entity After processing is completed, communicate with the base station using RLC PDU whose sequence number length is changed. It includes a step, wherein the indication is a communication method that includes an instruction to change the sequence number length RLC PDU to 11 bits or more when adding or deleting a secondary cell is provided. This communication method provides a technique capable of changing the length of the sequence number of the RLC PDU while suppressing the decrease in throughput.

<Supplement of embodiment>
In the above embodiment, when adding / deleting SCells, the length of the sequence number is changed, but it is not limited to this. For example, in the processing procedure of step S102 or step S202, the RRC connection Reconfiguration signal may not include the SCell addition / deletion instruction. Thereby, the length of the sequence number of the RLC PDU can be changed at any timing.

  The configuration of each device (user device UE / base station eNB) described in the present embodiment is a configuration realized by executing a program by a CPU (processor) in the device including a CPU and a memory. The configuration may be realized by hardware such as a hardware circuit provided with the logic of the processing described in this embodiment, or a combination of a program and hardware may be used.

  Although the embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art should understand various modifications, modifications, alternatives, replacements, and the like. I will. Although specific numerical examples are used to facilitate understanding of the invention, unless otherwise noted, those numerical values are merely examples and any appropriate values may be used. The division of items in the above description is not essential to the present invention, and the items described in two or more items may be used in combination as necessary, and the items described in one item may be used in another item. It may be applied to the matters described in (unless contradictory). The boundaries of the functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operations of multiple functional units may be physically performed by one component, or the operations of one functional unit may be physically performed by multiple components. The sequences and flowcharts described in the embodiments may be rearranged as long as there is no contradiction. Although the user apparatus UE and the base station eNB are described using a functional block diagram for convenience of the processing description, such an apparatus may be realized in hardware, software or a combination thereof. The software operated by the processor of the user apparatus UE according to the embodiment of the present invention and the software operated by the processor of the base station eNB according to the embodiment of the present invention are random access memory (RAM), flash memory, read only It may be stored in memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server or any other suitable storage medium.

  The present invention is not limited to the embodiments described above, and various modifications, alterations, alternatives, and replacements are included in the present invention without departing from the spirit of the present invention.

  In the embodiment, the RRC processing unit 23 is an example of a reception unit. The RLC processing unit 24 is an example of re-establishment means. The signal transmission unit 21, the signal reception unit 22, and the RLC processing unit 24 are an example of communication means. The RRC processing unit 23 is an example of a capability notification unit. The signal transmission unit 11 and the RRC processing unit 13 are an example of transmission means. The RLC processing unit 14 is an example of re-establishment means. The signal transmission unit 11, the signal reception unit 12, and the RLC processing unit 14 are an example of communication means.

UE user apparatus eNB base station 11 signal transmission unit 12 signal reception unit 13 RRC processing unit 14 RLC processing unit 15 MAC processing unit 21 signal transmission unit 22 signal reception unit 23 RRC processing unit 24 RLC processing unit 25 MAC processing unit

Claims (8)

A user equipment that communicates with a base station,
Reception means for receiving an instruction to change the sequence number length of the RLC PDU from the base station;
Re-establishment means for performing re-establishment processing of the RLC entity when the instruction is accepted;
Communication means for communicating with the base station using the RLC PDU whose sequence number length has been changed after the re-establishment process is completed;
Have
The instruction includes an instruction to change the sequence number length of the RLC PDU to 11 bits or more when adding or deleting a secondary cell.
User equipment. The instruction includes at least one of an instruction to change a sequence number length of RLC PDU in uplink and an instruction to change a sequence number length of RLC PDU in downlink,
When the communication means receives an instruction to change the sequence number length of the RLC PDU in uplink, the communication means communicates with the base station using the RLC PDU in uplink with the changed sequence number length, and receives the RLC PDU in downlink The user apparatus according to claim 1, wherein the terminal apparatus communicates with the base station using an RLC PDU in downlink for which the sequence number length has been changed, when receiving an instruction to change the sequence number length of. Notification means for notifying the base station that the user equipment has the ability to change the sequence number length of the RLC PDU,
The user device according to claim 1, further comprising: The instruction further includes an instruction indicating that handover processing is to be performed,
4. The re-establishment process according to any one of claims 1 to 3, wherein the re-establishment means performs the re-establishment process of the RLC entity by performing the handover process when the instruction to perform the handover process is received. User equipment as described.   The communication means performs handover processing without deactivating a secondary cell, when receiving an instruction indicating that the handover processing is to be performed and an instruction to change the sequence number length of the RLC PDU. User equipment as described.   The user apparatus according to claim 5, wherein the communication unit stops a deactivation timer while performing handover processing without deactivating a secondary cell. A base station that communicates with the user equipment,
Transmitting means for transmitting to the user apparatus an instruction to change the sequence number length of the RLC PDU;
Re-establishment means for performing re-establishment processing of the RLC entity when transmitting the instruction;
Communication means for communicating with the user apparatus using the RLC PDU whose sequence number length has been changed after the re-establishment process is completed;
Have
The instruction includes an instruction to change the sequence number length of the RLC PDU to 11 bits or more when adding or deleting a secondary cell.
base station. A communication method in a mobile communication system having a base station and a user apparatus, comprising:
The base station transmits, to the user apparatus, an instruction to change a sequence number length of an RLC PDU;
The user apparatus receiving the instruction from the base station;
The base station performs RLC entity re-establishment processing;
The user equipment performs RLC entity re-establishment processing;
The base station communicates with the user equipment using an RLC PDU whose sequence number length has been changed, after the reestablishment process of the RLC entity is completed;
The user equipment communicates with the base station using the RLC PDU whose sequence number length has been changed after the reestablishment process of the RLC entity is completed;
Have
The instruction includes an instruction to change the sequence number length of the RLC PDU to 11 bits or more when adding or deleting a secondary cell.
Communication method.

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