JP2016143913A - User device, and terminal identifier notification method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a user device notify a base station of a terminal identifier, so that identification of the user device by the base station is performed properly, when a plurality of terminal identifiers are assigned to the user device, in a mobile communication system where the user device and base station perform communication by using carrier aggregation.SOLUTION: A user device performing communication with a base station in a mobile communication system supporting carrier aggregation includes a management unit for receiving a terminal identifier of each cell or cell group in the carrier aggregation, from the base station, and holding the terminal identifier, and a transmission unit for transmitting a message, including a terminal identifier associated with a specific cell, out of the terminal identifiers held in the management unit, to the base station in the collision random access procedure executed in a specific cell out of a plurality of cells in the carrier aggregation.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a terminal identifier notification method in a mobile communication system such as LTE.

  The LTE system employs carrier aggregation (CA) that performs communication using a plurality of carriers simultaneously with a predetermined bandwidth as a basic unit. A carrier that is a basic unit in carrier aggregation is called a component carrier (CC).

  When CA is performed, a PCell (Primary cell) that is a highly reliable cell that ensures connectivity and a SCell (Secondary cell) that is an ancillary cell are set for the user apparatus UE. First, the user apparatus UE can connect to the PCell and add an SCell as necessary. The PCell is a cell similar to a single cell that supports RLM (Radio Link Monitoring), SPS (Semi-Persistent Scheduling), and the like.

  The addition and deletion of the SCell is performed by RRC (Radio Resource Control) signaling. Immediately after being set for the user apparatus UE, the SCell is a cell that is in an inactive state (deactivated state), and thus can be communicated (schedulable) only when activated.

  As shown in FIG. 1, for example, LTE Rel. In 10 CAs, a plurality of CCs under the same base station eNB are used. Also, Rel. In 10 CAs, for example, as shown in FIG. 2, a maximum data rate is realized by bundling up to 5 CCs by bundling.

  Rel. 12, Dual connectivity (double connection) is introduced that performs simultaneous communication using CCs under different base stations eNB and realizes high throughput. In dual connectivity, the UE performs communication using radio resources of a plurality of physically different base stations eNB at the same time.

  Dual connectivity (hereinafter referred to as DC) is a type of CA, also called Inter eNB CA (inter-base station carrier aggregation), and introduces Master-eNB (MeNB) and Secondary-eNB (SeNB).

  In DC, a cell group composed of cells (one or more) under the MeNB is defined as a MCG (Master Cell Group), and a cell group composed of cells (one or a plurality) under the SeNB is defined as SCG ( (Secondary Cell Group, secondary cell group). The MCG has a PCell, and in addition, can have an SCell. The SCG includes one or a plurality of SCells, and a UL CC is set in at least one SCell of the SCGs, and a PUCCH is set in one of them. This SCell is called PSCell (primary SCell).

3GPP TSG RAN Meeting # 66 RP-142286 Maui, Hawaii (US), December 8-11, 2014 3GPP TS 36.300 V12.4.0 (2014-12) 3GPP TS 36.321 V12.4.0 (2014-12)

  Rel. With up to 12 CAs, the maximum number of CCs that can be configured per UE is 5.

  On the other hand, Rel. In 13 LTE, in order to realize more flexible and high-speed wireless communication, and to allow a large number of CCs to be bundled in a continuous ultra-wideband unlicensed band, a maximum of 5 CCs bundled in CA is limited. CA enhancement to be taken is being considered. For example, CA that bundles up to 32 CC (= 640 MHz) has been studied (Non-Patent Document 1). As an example, FIG. 3 shows an example of bundling 32CC.

  By the way, in LTE, C-RNTI (Cell-Radio. Network Temporary Identifier) is used as an identifier (which can be called a terminal identifier) for identifying the user apparatus UE. For example, for the user apparatus UE in the RRC connection state, the base station eNB transmits allocation information masked with the C-RNTI allocated to the user apparatus UE, and the user apparatus UE uses its own C-RNTI. Decrypt the allocation information.

  Moreover, in the user apparatus UE in the RRC connection state, for example, when uplink data is generated from a state where there is no communication, the user apparatus UE performs an uplink resource by executing contention based random access (CBRA). Receive an assignment.

  FIG. 4 shows a CBRA procedure between the user apparatus UE and the base station eNB. User apparatus UE transmits RA preamble by PRACH (step 1). The base station eNB that has received the RA preamble returns an RA response (step 2). The RA response includes transmission timing information, allocation information (UL grant), and the like. The allocation information is uplink resource allocation information for transmitting the next message 3 (described as Msg3).

  The user apparatus UE that has received the RA response transmits Msg3 including the C-RNTI assigned to the user apparatus UE to the base station eNB (step 3). Based on the C-RNTI, the base station eNB identifies that the user apparatus UE is a user apparatus UE that is RRC-connected. For example, the base station eNB transmits a PDCCH including uplink resource allocation information masked with the C-RNTI to the user apparatus Transmit to UE (step 4). The user apparatus UE can acquire the uplink resource allocation information by C-RNTI, recognizes that the random access has succeeded without collision (Contention resolution), and performs the next uplink transmission based on the uplink resource allocation information. Run.

  Rel. In CA up to 12, it is specified that the same C-RNTI is used in all PCells and SCells set in the user apparatus UE (Non-patent Document 2). On the other hand, as described above, when extended to 32 CC, it is assumed that it is not easy to secure the same C-RNTI in all 32 cells. That is, if it is going to use the same C-RNTI in all 32 cells, the possibility that the cell which the collision of C-RNTI between UE will generate | occur | produce will become high. If C-RNTI is reserved in advance to avoid this, C-RNTI may be insufficient. Therefore, in 32CC, it is assumed that several C-RNTI is allocated with respect to UE. FIG. 5 shows an example of assigning a plurality of C-RNTIs in CA. In the example of FIG. 5, a different C-RNTI is assigned to each cell group (CG) constituting the CA.

  In the conventional LTE, since the user apparatus UE always has only one C-RNTI, the CBRA Msg3 described in FIG. 4 reports the already assigned C-RNTI to the base station eNB ( Non-patent document 3).

  As described above, when there are a plurality of C-RNTIs, there is no definition of how C-RNTIs should be reported to the base station eNB. From this, for example, there is a problem shown in FIG. In the example of FIG. 6, C-RNTI # X is assigned to UE1 in cell #A, and C-RNTI # Y is assigned to UE3 in cell #B. UE2 performs CA by cell #A and cell #B. In UE2, C-RNTI # Y is assigned to cell #A, and C-RNTI # X is assigned to cell #B.

  In CBRA, UE1 reports C-RNTI # X to eNB10 in cell #A, and UE3 reports C-RNTI # Y to eNB10 in cell #B. As described above, the C-RNTI reporting method of UE2 is not specified, but here, for example, CBRA is started in cell #A or cell #B, and C-RNTI # X and C-RNTI # Y are started in Msg3. Both are reported to the eNB 10.

  In this case, the eNB 10 cannot identify whether the C-RNTI # X is of UE1 or UE2, and cannot identify whether the C-RNTI # Y is of UE3 or UE2. That is, the UE cannot be uniquely identified on the eNB side.

  The present invention has been made in view of the above points, and in a mobile communication system in which a user apparatus and a base station communicate using carrier aggregation, when a plurality of terminal identifiers are assigned to the user apparatus, the base station An object of the present invention is to provide a technique for a user apparatus to notify a base station of a terminal identifier so that the user apparatus can be properly identified.

According to an embodiment of the present invention, a user apparatus that communicates with a base station in a mobile communication system that supports carrier aggregation,
A management unit that receives and holds a terminal identifier for each cell or cell group in the carrier aggregation from the base station;
In a collision type random access procedure executed in a specific cell among a plurality of cells in the carrier aggregation, a message including a terminal identifier associated with the specific cell among terminal identifiers held in the management unit A user apparatus comprising: a transmission unit that transmits a message to the base station.

Moreover, according to the embodiment of the present invention, a terminal identifier notification method executed by a user apparatus that communicates with a base station in a mobile communication system that supports carrier aggregation,
Receiving and retaining a terminal identifier for each cell or cell group in the carrier aggregation from the base station; and
In a collision random access procedure executed in a specific cell among a plurality of cells in the carrier aggregation, a message including a terminal identifier associated with the specific cell among the terminal identifiers held in the step A terminal identifier notification method comprising: transmitting to the base station.

  According to an embodiment of the present invention, in a mobile communication system in which a user apparatus and a base station communicate using carrier aggregation, when a plurality of terminal identifiers are assigned to the user apparatus, the user apparatus is identified by the base station. It is possible for the user equipment to notify the base station of the terminal identifier so as to be performed appropriately.

Rel. It is a figure for demonstrating 10 CA. Rel. It is a figure which shows the example which bundles CC in 10 CA. It is a figure which shows the example which bundles 32CC in CA of Re1.13. It is a figure which shows the procedure of collision type random access. It is a figure which shows the example in the case of assigning several C-RNTI in CA. It is a figure for demonstrating a subject. 1 is a configuration diagram of a system in an embodiment of the present invention. It is a figure for demonstrating the process sequence example in this Embodiment. It is a figure which shows the example of the allocation method of C-RNTI. It is a figure for demonstrating the example of the transmission method of C-RNTI. It is a figure for demonstrating the example of the transmission method of C-RNTI. It is a figure which shows the whole operation | movement image. It is a figure which shows the example of a procedure in the case of changing C-RNTI other than C-RNTI of PCell. It is a figure for demonstrating the notification method of Capability. It is a figure for demonstrating the operation example at the time of cross-carrier scheduling. It is a figure for demonstrating the example of the transmission method of UCI. It is a figure for demonstrating the example of the transmission priority based on C-RNTI allocation. It is a block diagram of the user apparatus UE which concerns on this Embodiment. It is a block diagram of the base station eNB which concerns on this Embodiment. It is a flowchart which shows the operation example of the user apparatus UE which concerns on this Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. The embodiment described below is only an example, and the embodiment to which the present invention is applied is not limited to the following embodiment. Although the present embodiment is directed to an LTE mobile communication system, the present invention is not limited to LTE, and can be applied to other mobile communication systems employing carrier aggregation.

  Moreover, below, the cell group (CG) which consists of several cells which comprise CA is used. Although MCG and SCG in DC are examples of CG, CG is a concept that is not limited to MCG and SCG, and a group of a plurality of cells from some point of view is called CG. In addition, the CG includes a case of one cell. The “cell” constituting the CA is a cell in which the user apparatus UE is located, and may be referred to as a serving cell. Further, as an example, the “cell” constituting the CA consists of only a downlink CC, or a downlink CC and an uplink CC. Further, the release of the “LTE” 3GPP standard in this specification and the claims is a release in which CA (including DC) is introduced, but is not limited to this. In the embodiment described below, the C-RNTI transmission in the CBRA procedure is targeted. However, the C-RNTI transmission may be performed by a procedure other than the CBRA procedure.

  Moreover, in this Embodiment, although C-RNTI is notified as a terminal identifier, the terminal identifier to notify is not restricted to C-RNTI.

(Whole system configuration)
FIG. 7 shows a configuration diagram of a communication system in the embodiment of the present invention. As shown in FIG. 7, the communication system in the present embodiment is a mobile communication system including a base station eNB and a user apparatus UE. CA communication can be performed between the base station eNB and the user apparatus UE. In FIG. 7, one base station eNB and one user apparatus UE are shown, but this is for convenience of illustration, and there may be a plurality of each.

  Also, in the example of FIG. 7, one cell is shown, but this is also for convenience of illustration, and there are a plurality of cells when CA is set. Further, for example, a configuration in which one or a plurality of RREs (remote radio apparatuses) connected to the base station eNB by an optical fiber or the like is provided in a place away from the base station eNB may be employed. Moreover, the structure of Dual Connectivity provided with the some base station eNB may be sufficient. When targeting dual connectivity, when the user apparatus UE transmits a PRACH in the MCG (a certain cell) and starts the CBRA procedure, the user apparatus UE transmits Msg3 to the MeNB, and the user apparatus UE is SCG When the PRACH is transmitted in the cell) and the CBRA procedure is started, it is assumed that the user apparatus UE transmits Msg3 to the SeNB. Therefore, the base station eNB described below includes such a MeNB and SeNB semantically. Note that the CBRA procedure in DC is not limited to this.

  In this Embodiment, in order to solve the subject mentioned above, in the CBRA procedure, the user apparatus UE is supposed to make C-RNTI linked | related with the cell which performs a CBRA procedure the base station eNB by Msg3. Hereinafter, the contents of processing in the present embodiment will be described in more detail.

(Details of processing)
With reference to FIG. 8, an example of a processing sequence in the present embodiment will be described. As a premise of FIG. 8, the user apparatus UE is in an RRC connection state with the base station eNB.

  First, in step 101, base station eNB notifies C-RNTI for every cell (serving cell) which comprises CA with respect to user apparatus UE. “For each cell” includes the case of notifying the C-RNTI for each cell group (CG). This notification is performed using, for example, an RRC connection reconfiguration message, but may be performed using a MAC signal or the like.

  The user apparatus UE and the base station eNB perform signal transmission / reception using the C-RNTI assigned to each cell with respect to the user apparatus UE (step 102). For example, when CA is configured by the cell # 1 and the cell # 2 in the user apparatus UE, the C-RNTI # 1 is allocated to the cell # 1, and the C-RNTI # 2 is allocated to the cell # 2, the base The station eNB transmits the PDCCH in cell # 1 using C-RNTI # 1, and transmits the PDCCH in cell # 2 using C-RNTI # 2. The user apparatus UE acquires assignment information using C-RNTI # 1 / C-RNTI # 2 in cell # 1 / cell # 2, and performs data transmission or reception in each cell.

  Regarding the C-RNTI notification, a CA composed of a plurality of cells may be set in the user apparatus UE at a time point before step 101, and the C-RNTI may be notified in step 101. The C-RNTI may be notified in the addition instruction. In addition, when Step 101 is an instruction to add an SCell and the C-RNTI is not notified, the user apparatus UE has assigned the same C-RNTI to the SCell as the C-RNTI of the already assigned PCell. May be considered.

  Moreover, the base station eNB notifies C-RNTI with respect to SCell to add, for example, whenever it performs SCell addition setting to the user apparatus UE. Further, for example, while adding SCell, the base station eNB explicitly or implicitly notifies the same C-RNTI as the PCell up to a predetermined number of cells (for example, 16), and exceeds the predetermined number of cells. When C is set, C-RNTI different from PCell may be explicitly notified. Implicit notification means, for example, that C-RNTI is not notified in addition of SCell until the number of cells reaches a predetermined number.

  Moreover, in this Embodiment, in the cell group (CG) with the same C-RNTI, at least 1 cell which transmits PUCCH may be set.

  FIG. 9 shows a specific example of C-RNTI allocation. FIG. 9A shows an example in which the same C-RNTI as that of the PCell is allocated up to a predetermined number of cells, and thereafter, C-RNTI is allocated for each predetermined number. The C-RNTI is assigned to the cell # 1 to the cell # 16. An example in which # 1 is assigned and C-RNTI # 1 is assigned to cell # 17 to cell # 32 is shown.

  FIG.9 (b) has shown the example in case the cell which transmits PUCCH is set one by one in CG with the same C-RNTI. Specifically, PUCCH transmission is possible in cell # 3 among CGs (cell # 1 to cell # 3) to which C-RNTI # 1 is assigned, and CG (cell # to which C-RNTI # 2 is assigned). 5, cell # 6 among cells # 6,...) Can be PUCCH transmitted. “PUCCH transmission is possible” means, for example, that PUCCH resources are allocated to both ends of the band in the uplink CC of the corresponding cell.

  In step 103 of FIG. 8, for example, when uplink data to be transmitted is generated from a state in which uplink data transmission of the user apparatus UE is interrupted, and the CBRA procedure is triggered, the user apparatus UE transmits an RA preamble using the PRACH. I do.

  In step 103, the user apparatus UE that has transmitted the PRACH in a certain cell receives an RA response from the base station eNB in the cell (step 104).

  In step 105, the user apparatus UE includes the C-RNTI assigned to the cell in Msg3 and transmits the Msg3 in the cell. More specifically, Msg3 includes a C-RNTI MAC CE (Control Element) in which the C-RNTI is set. Since the base station eNB associates and manages the cell, the C-RNTI, and the UE, the C-RNTI included in the Msg3 received in the cell can uniquely identify the user apparatus UE that has transmitted the Msg3, Thereafter, assignment information and the like are transmitted to the identified user apparatus UE.

<Example of C-RNTI transmission method>
In the present embodiment, in the CBRA procedure, when the user apparatus UE can transmit the PRACH only in a specific cell (PCell here), the first CBRA is used, and the user apparatus UE can transmit the PRACH in an arbitrary cell Is the second CBRA.

  In 1st CBRA, user apparatus UE transmits PRACH (RA preamble) by PCell, receives RA response by PCell, and transmits Msg3 by PCell.

  In the second CBRA, the user apparatus UE transmits a PRACH in an arbitrary cell, receives an RA response in the cell, and transmits Msg3 in the cell. In the second CBRA, the cell in which the CBRA procedure is executed is not particularly limited. For example, a cell having a good radio quality can be selected and the CBRA procedure can be executed.

  In 1st CBRA (CBRA only by PCell), in step 105 of FIG. 8, the user apparatus UE always includes the C-RNTI of the PCell in Msg3 and transmits.

  In the second CBRA (CBRA is possible in an arbitrary cell), when the user apparatus UE transmits Msg3 in the cell associated with the PCell or the same C-RNTI as the PCell in Step 105 of FIG. RNTI is notified to base station eNB by Msg3.

  Moreover, in step 105 of FIG. 8 in 2nd CBRA, when user apparatus UE transmits Msg3 by the cell to which C-RNTI different from PCell was allocated, C-RNTI of the said cell is included in Msg3, and it is in base station eNB. Notice.

  That is, in the second CBRA, the user apparatus UE notifies the base station eNB of the C-RNTI assigned to the user apparatus UE with respect to the cell on which the CBRA is performed using Msg3.

  A specific example is shown in FIG. FIGS. 10 (a) and 10 (b) show states in which the base station eNB has set the CA composed of PCell and SCell in the user apparatus UE. FIG. 10A shows an example in which the CBRA procedure is executed in the PCell. In this case, the user apparatus UE transmits Msg3 including the C-RNTI of the PCell using the PCell. FIG.10 (b) is an example in case a CBRA procedure is performed by SCell, In this case, user apparatus UE transmits Msg3 containing C-RNTI of SCell by SCell. In the example of FIG. 10B, for example, when the same C-RNTI as that of the PCell is also assigned to the SCell, the user apparatus UE transmits Msg3 including the C-RNTI of the PCell using the SCell.

  In the above example, the user apparatus UE transmits one C-RNTI included in Msg3. However, a plurality of C-RNTIs may be included in Msg3 and transmitted. In this case, for example, the C-RNTI corresponding to the cell executing the CBRA procedure is stored immediately after the MAC header, and the other C-RNTI assigned to the UE is stored next. An example of the MAC PDU in this case is shown in FIG. In the example of FIG. 11, C-RNTI # 1 is stored in MAC CE1 immediately after the MAC header, and C-RNTI # 2 is stored in the next MAC CE2.

  When a plurality of C-RNTIs are included in Msg3 as described above, the base station eNB identifies the UE with reference to the C-RNTI stored immediately after the MAC header. When a plurality of C-RNTIs are included in Msg3, storing the C-RNTI to be referenced immediately after the MAC header is merely an example. If the base station eNB can identify the C-RNTI to be referred to, the C-RNTI to be referred to may be stored in any position.

  FIG. 12 shows an overall operation image in the present embodiment. This example corresponds to the example shown in FIG. 6, in which C-RNTI # X is assigned to UE1 in cell #A, and C-RNTI # Y is assigned to UE3 in cell #B. UE2 performs CA by cell #A and cell #B. In UE2, C-RNTI # Y is assigned to cell #A, and C-RNTI # X is assigned to cell #B.

  In the CBRA procedure, UE1 reports C-RNTI # X to eNB10 in cell #A, and UE3 reports C-RNTI # Y to eNB10 in cell #B.

  UE2 reports C-RNTI # Y assigned to cell #A to eNB10 when executing the CBRA procedure in cell #A, and cell2 when executing the CBRA procedure in cell #B. C-RNTI #X assigned to #B is reported to eNB 10. With such a reporting method, the eNB 10 can specify the UE that has accessed in each cell.

  Hereinafter, various processing examples executed on the premise of the basic processing in the present embodiment described above will be described.

(Release and change of C-RNTI)
The C-RNTI once allocated to the user apparatus UE is released as appropriate. For example, when the RRC connection between the user apparatus UE and the base station eNB is disconnected, the C-RNTI may be released.

  In addition, when the user apparatus UE reconnects to the base station eNB, the user apparatus UE autonomously deletes the SCell, and thus the C-RNTI of the SCell to be deleted may be released. Since the user apparatus UE includes the Cell RNTI of the PCell in the reconnection request message, the user apparatus UE holds the Cell RNTI of the PCell without releasing it.

  In order to change the C-RNTI used by the user apparatus UE for communication in the RRC connection state, it is necessary to execute an intra-cell HO (intra-cell handover) procedure from the base station eNB.

  Conventionally, when Intra-cell HO is executed, all cells constituting the CA are deactivated. On the other hand, when the user apparatus UE holds the C-RNTI for each cell (or for each CG) constituting the CA as in the present embodiment, all cells are deactivated by Intra-cell HO as in the past. That is not desirable.

  Therefore, in the present embodiment, when changing the C-RNTI of the PCell, Intra-cell HO is performed as before. In this case, all SCells are deactivated. However, it is good also as not deactivating about SCell to which C-RNTI of PCell is not allocated.

  On the other hand, when changing the C-RNTI other than the PCell C-RNTI (e.g., the SCell C-RNTI), the base station eNB changes the RRC connection reconfiguration indicating the SCell Intra-cell HO. C-RNTI is notified. Receiving the notification, the user apparatus UE once deactivates all the target cells (cells to which the C-RNTI to be changed is assigned), and changes the C-RNTI. In this case, the cell to which the C-RNTI other than the C-RNTI to be changed is not affected (not deactivated).

  FIG. 13 shows an example of the latter procedure for changing the C-RNTI. As illustrated in FIG. 13, when the user apparatus UE receives RRC connection reconfiguration including the changed C-RNTI (step 201), only the target cell (SCell in this case) is deactivated, and the C-RNTI change is performed. (Step 202). When the process for the RRC connection reconfiguration is completed, an RRC connection reconfiguration complete is returned (step 203).

(Capability notification)
In the present embodiment, a plurality of C-RNTIs can be set for one user apparatus UE, but the number of C-RNTIs that can be set depends on the capacity of the user apparatus UE such as a memory. . However, there is no mechanism for notifying the capability in the prior art.

  Therefore, in the present embodiment, the user apparatus UE notifies the base station eNB of the number of C-RNTIs that can be set in the user apparatus UE as capability information (capability). FIG. 14 shows an example of the capability notification procedure. For example, when the user apparatus UE makes an RRC connection to the base station eNB, the user apparatus UE receives a capability information inquiry (UE Capability Enquiry) from the base station eNB (step 301), and the user apparatus UE can set C-RNTI. The capability information (UE Capability information) including the number of is transmitted to the base station eNB (step 302). In the example in this case, it is notified that the user apparatus UE can set up to four C-RNTIs.

  In notifying the setting capability of C-RNTI, the number may be explicitly notified as described above, or the user apparatus UE may be implicitly notified by the number of cells (number of CCs) that can be set by CA. Good. For example, when the user apparatus UE notifies the base station eNB of the number of cells of 6 to 16 cells as CA capability information, the base station eNB can set up to two C-RNTIs in the user apparatus UE. If it is determined that the user apparatus UE notifies the base station eNB of the number of cells of 16 cells or more, the base station eNB determines that up to four C-RNTI settings are possible in the user apparatus UE.

(Cross carrier scheduling)
In CA, it is possible to perform resource allocation in another cell by PDCCH transmitted from a base station eNB in a certain cell, and this is referred to as cross carrier scheduling (CCS).

  In conventional cross-carrier scheduling, the user apparatus UE uses the same C-RNTI for decoding PDCCH in a scheduling cell, which is a cell to which PDCCH is transmitted, and for decoding PDSCH in an allocated cell, in which resources are allocated by scheduling. Is used. On the other hand, in the case of the present embodiment where the C-RNTI may be different between the scheduling cell and the allocated cell, decoding is performed using the C-RNTI as in the following Method Example 1 or Method Example 2.

  Method Example 1 performs decoding using the C-RNTI of the scheduling cell even in an allocation cell different from the scheduling cell. In Method Example 1, since the user apparatus UE uses a single C-RNTI, decoding is easy. The base station eNB of Method Example 1 executes generation of PDCCH in the scheduling cell and generation of PDSCH in the allocated cell using C-RNTI in the scheduling cell, corresponding to the operation of the UE.

  In Method Example 2, the user apparatus UE decodes the PDCCH using the C-RNTI of the scheduling cell, and decodes the PDSCH using the C-RNTI of the allocated cell. In response to the operation of the UE, the base station eNB of Method Example 2 generates a PDCCH using the C-RNTI of the scheduling cell and generates a PDSCH using the C-RNTI of the allocated cell. In Method Example 2, from the viewpoint of the base station eNB, it is not necessary to link C-RNTIs that are decoded between cells, so that the scheduler configuration can be simplified.

  A specific example is shown in FIG. In the example of FIG. 15, the PDCCH addressed to the user apparatus UE is transmitted in the cell # 1 as indicated by “A”. The PDCCH allocates the PDSCH in the cell # 2 indicated by “B” to the user apparatus UE. In Method Example 1, the user apparatus UE performs PDCCH decoding and PDSCH decoding using the C-RNTI of cell # 1. In Method Example 2, the user apparatus UE decodes the PDCCH using the C-RNTI of the cell # 1, and decodes the PDSCH using the C-RNTI of the cell # 2.

  In the above example, downlink (DL) has been described as an example, but the same applies to uplink (UL). In the UL, for example, the user apparatus UE uses the C-RNTI of the scheduling cell or uses the C-RNTI of the allocated cell at the time of PUSCH transmission.

(UCI transmission method)
In LTE, the user apparatus UE transmits UCI (Uplink Control Information) such as ACK / NACK, CQI, PMI, RI, and SR to the base station eNB. When there is a PUSCH resource at the timing of UCI transmission, the user apparatus UE transmits the UCI on the PUSCH. This is called UCI piggyback. When there is no PUSCH resource at the timing of UCI transmission, UCI is transmitted on PUCCH.

  As described above, in the present embodiment, it is possible to adopt a mode in which at least one cell that transmits PUCCH is set in a cell group having the same C-RNTI (example: FIG. 9B). In this case, for example, UCIs of cells having the same C-RNTI are multiplexed on each PUCCH. Or, regardless of C-RNTI, UCI of all cells may be multiplexed on PUCCH of PCell.

  An example in which the UCI of a cell having the same C-RNTI is multiplexed on each PUCCH is shown in FIG. As shown in FIG. 16 (a), the same C-RNTI # 1 is allocated in CG # 1 composed of cell # 1 and cell # 2, and the UCI of cell # 2 and the UCI of cell # 1 # 1 is transmitted on PUCCH.

  When there are PUSCH resources at the timing of UCI transmission and there are a plurality of C-RNTIs related to the piggyback to UCI PUSCH, there are the following method example 1 and method example 2.

  In Method Example 1, the user apparatus UE performs UCI piggyback only between cells to which the same C-RNTI is assigned. For example, in the example shown in CG # 2 in FIG. 16A, UCI piggyback is performed only between the cell # 3 and the cell # 4 to which the same C-RNTI # 2 is assigned.

  When UCI piggyback is performed only between cells to which the same C-RNTI is assigned, when there are a plurality of PUSCHs in a plurality of cells to which the same C-RNTI is assigned, for example, user equipment The UE transmits the UCI multiplexed on the PUSCH of the cell having the smallest CellIndex between cells to which the same C-RNTI is allocated. Multiplexing to the cell with the smallest CellIndex is merely an example, and multiplexing to the cell with the largest CellIndex may be performed, or the cell to be multiplexed may be determined by another method.

  Moreover, as shown in FIG.16 (b), the user apparatus UE is good also as implementing UCI piggyback with respect to PUSCH to which different C-RNTI was allocated. That is, in the example of FIG. 16B, UCIs of the cell # 1 and the cell # 2 to which the C-RNTI # 1 is allocated are transmitted using the PUSCH of the cell # 3 to which the C-RNTI # 2 is allocated. Has been.

(UL transmission priority control based on C-RNTI allocation)
In general, the uplink transmission resource / uplink transmission power is limited. Therefore, for example, when the signal transmission timing from multiple cells overlaps, only the signal of a certain cell is transmitted, the transmission of another cell is stopped (Drop), or only the signal of a certain cell is transmitted with normal power. The transmission power of other cells is reduced (Scaling).

  In the present embodiment, the drop / scaling control as described above in the user apparatus UE can be performed based on the C-RNTI.

  For example, since the PCell is a cell that guarantees connectivity, as shown in FIG. 17, the priority of UL transmission in the SCell having the same C-RNTI as the PCell is set as the priority of UL transmission in other SCell. Implement control to make it higher than the degree.

  More specifically, for example, in the user apparatus UE, when transmission of CSI (Channel State Information) such as CQI (eg, periodic transmission) is set for each cell, the user apparatus UE is the same as the PCell. When the CSI transmission timing of the cell having the C-RNTI and the cell having no C-RNTI overlap, the latter CSI is dropped. In addition, for example, when the UL transmission timing of a cell having the same C-RNTI as that of the PCell overlaps with the UL transmission timing of the other cell, the user apparatus UE preferentially scales or drops the latter UL transmission. .

(Device configuration example)
Next, main configurations of the user apparatus UE and the base station eNB capable of executing all the processes described so far will be described.

  First, in FIG. 18, the functional block diagram of the user apparatus UE which concerns on this Embodiment is shown. As illustrated in FIG. 18, the user apparatus UE includes a UL signal transmission unit 101, a DL signal reception unit 102, an RRC management unit 103, and a C-RNTI transmission control unit 104. FIG. 18 shows only functional units that are particularly related to the embodiment of the present invention in the user apparatus UE, and also has a function (not shown) for performing an operation based on at least LTE. Further, the functional configuration shown in FIG. 18 is merely an example. As long as the operation according to the present embodiment can be performed, the function classification and the name of the function unit may be anything.

  The UL signal transmission unit 101 includes a function of generating and wirelessly transmitting various physical layer signals from higher layer signals to be transmitted from the user apparatus UE. The DL signal receiving unit 101 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. Each of the UL signal transmission unit 101 and the DL signal reception unit 102 includes a function of executing CA that performs communication by bundling a plurality of CCs.

  Each of the UL signal transmission unit 101 and the DL signal reception unit 102 is assumed to include a packet buffer and perform layer 1 (PHY) and layer 2 (MAC, RLC, PDCP) processing. However, it is not limited to this. Further, the UL signal transmission unit 101 and the DL signal reception unit 102 can execute communication, UCI transmission, UL transmission priority control, and the like based on the cross carrier scheduling described so far.

  The RRC management unit 103 includes a function of performing processing such as setting / change / management of CA information, configuration change and the like while performing transmission / reception of RRC messages with the base station eNB. In addition, the RRC management unit 103 includes storage means for receiving C-RNTI allocation for each cell (for each CG) from the base station eNB and holding the C-RNTI. The RRC management unit 103 also includes a function of holding information on capability (capability) of the user apparatus UE and notifying the base station eNB of information on capability. The RRC management unit 103 includes a function for releasing and changing the C-RNTI.

  C-RNTI transmission control section 104 performs transmission control of C-RNTI according to the present embodiment to base station eNB. That is, in the CBRA procedure, when the UL signal transmission unit 101 transmits Msg3, the C-RNTI transmission control unit 104 sets the C-RNTI assigned to the cell that transmits Msg3 (the cell that executes the CBRA procedure) to Msg3. Instruct to send in Note that the C-RNTI transmission control unit 104 may be included in the UL signal transmission unit 101.

  FIG. 19 shows a functional configuration diagram of the base station eNB according to the present embodiment. As illustrated in FIG. 19, the base station eNB includes a DL signal transmission unit 201, a UL signal reception unit 202, an RRC management unit 203, and a scheduling unit 204. FIG. 19 shows only functional units that are particularly related to the embodiment of the present invention in the base station eNB, and has at least a function (not shown) for performing an operation based on LTE. Further, the functional configuration shown in FIG. 19 is merely an example. As long as the operation according to the present embodiment can be performed, the function classification and the name of the function unit may be anything.

  The DL signal transmission unit 201 includes a function of generating and wirelessly transmitting various physical layer signals from higher layer signals to be transmitted from the base station eNB. The UL signal receiving unit 202 includes a function of wirelessly receiving various signals from each UE and acquiring a higher layer signal from the received physical layer signal. Each of the DL signal transmission unit 201 and the UL signal reception unit 202 includes a function of executing CA (including CA in DC) that performs communication by bundling a plurality of CCs. Further, the DL signal transmission unit 201 and the UL signal reception unit 202 may be radio communication units installed remotely from the main body (control unit) of the base station eNB, like RRE.

  Each of the DL signal transmission unit 201 and the UL signal reception unit 202 includes a packet buffer, and is assumed to perform layer 1 (PHY) and layer 2 (MAC, RLC, PDCP) processing (however, this is not the only case). Not.)

  The RRC management unit 203 includes a function of transmitting / receiving an RRC message to / from the user apparatus UE and performing processing such as CA setting / change / management and configuration change. Since the RRC management unit 203 is a functional unit that performs CA setting, it may be referred to as a setting unit. Further, the RRC management unit 203 includes storage means for allocating C-RNTI for each cell (for each CG) to the user apparatus UE and storing the cell (CG), C-RNTI, and UE in association with each other.

  The scheduling unit 204 performs scheduling for each cell for the user equipment UE that performs CA, creates PDCCH allocation information using C-RNTI by the method described above, and transmits PDCCH including the allocation information. A function of instructing the DL signal transmission unit 201 is included.

  As an operation example, FIG. 20 shows a flowchart of the operation of the user apparatus UE. Here, it is assumed that the user apparatus UE is in an RRC connection state, CA is set, and C-RNTI for each cell constituting the CA is assigned.

  For example, when uplink data occurs in the user apparatus UE, the UL signal transmission unit 101 of the user apparatus UE activates a CBRA (collision-type RA) procedure (step 401), and transmits an RA preamble in the cell #A (step 401). 402). The user apparatus UE receives the RA response in the cell #A (step 403). The C-RNTI transmission control unit 104 of the user apparatus UE detects that the CBRA procedure is performed in the cell #A from step 402, step 403, etc., and includes the C-RNTI corresponding to the cell #A in Msg3 The UL signal transmission unit 101 is instructed to transmit. The UL signal transmission unit 101 includes the C-RNTI MAC CE in which the C-RNTI is set in the Msg3, and transmits the Msg3 in the cell #A (step 404).

(Summary of embodiment)
As described above, in the present embodiment, a user apparatus that communicates with a base station in a mobile communication system that supports carrier aggregation, from the base station, for each cell or each cell group in the carrier aggregation. The management unit that receives and holds the terminal identifier, and the identification among the terminal identifiers held in the management unit in a collision-type random access procedure executed in a specific cell among a plurality of cells in the carrier aggregation There is provided a user apparatus including a transmission unit that transmits a message including a terminal identifier associated with a cell to the base station. In this configuration, since the message including the terminal identifier associated with the specific cell is transmitted to the base station, the user equipment that has accessed the base station when a plurality of terminal identifiers are assigned to the user equipment Can be properly identified.

  The management unit may receive a setting message for adding a cell in the carrier aggregation from the base station, and hold a terminal identifier included in the setting message. With this configuration, since the terminal identifier can be notified in the setting message for adding a cell, the number of signaling can be reduced.

  The message transmitted by the transmitter includes a MAC signal, and the MAC signal stores a terminal identifier associated with the specific cell immediately after the MAC header, and another terminal identification after the terminal identifier. May be stored. With this configuration, the base station can identify the user device by referring to the terminal identifier (predetermined storage location) immediately after the MAC header.

  When the management unit receives a message including a changed terminal identifier for changing a terminal identifier already held from the base station, the management unit deactivates each cell associated with the terminal identifier. It is good as well. In this configuration, when a terminal identifier is changed, a cell that is not associated with the terminal identifier can be prevented from being affected, and the terminal identifier can be changed without affecting communication as much as possible.

  The management unit may notify the base station of capability information including the number of terminal identifiers that can be set in the user apparatus. With this configuration, since the base station can grasp the number of terminal identifiers that can be set in the user apparatus, it is possible to execute assignment of terminal identifiers according to the number.

  When the base station executes cross carrier scheduling for the user apparatus, the user apparatus can perform communication using the same terminal identifier in a plurality of cells related to cross carrier scheduling. With this configuration, the decoding process in the user device can be easily performed.

  When the base station performs cross-carrier scheduling for the user apparatus, the user apparatus performs communication using a terminal identifier associated with each cell in a plurality of cells related to cross-carrier scheduling. It is good. In this configuration, since it is not necessary to link terminal identifiers between cells on the base station side, the scheduling process is simplified.

  The plurality of cells constituting the carrier aggregation are grouped into one or a plurality of cell groups, the same terminal identifier is assigned to each cell in each cell group, and PUCCH is set in at least one cell in each cell group In this case, for example, the transmission unit transmits uplink control information of a cell to which the same terminal identifier is allocated using the PUCCH in each cell group. With this configuration, since the PUCCH to which uplink control information for each cell is to be transmitted is clearly defined, uplink control information can be accurately transmitted.

  The transmission unit uses the PUSCH when the PUSCH resource exists in a cell having the same terminal identifier as the terminal identifier assigned to the cell at the transmission timing of the uplink control information in a certain cell. It is good also as transmitting. With this configuration, since the PUSCH to which uplink control information for each cell is to be transmitted is clearly determined, uplink control information can be transmitted accurately.

  The user apparatus UE described in the present embodiment may include a CPU and a memory, and may be realized by a program being executed by a CPU (processor). The first and second embodiments may be used. The configuration may be realized by hardware such as a hardware circuit provided with the processing logic described in the above, or a program and hardware may be mixed.

  The base station eNB described in the present embodiment may include a CPU and a memory, and may be realized by a program being executed by a CPU (processor). The first and second embodiments The configuration may be realized by hardware such as a hardware circuit provided with the processing logic described in the above, or a program and hardware may be mixed.

  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 will understand various variations, modifications, alternatives, substitutions, and the like. I will. Although specific numerical examples have been described in order to facilitate understanding of the invention, these numerical values are merely examples and any appropriate values may be used unless otherwise specified. The classification 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, or the items described in one item may be used in different items. It may be applied to the matters described in (if not inconsistent). The boundaries between functional units or processing units in the functional block diagram do not necessarily correspond to physical component boundaries. The operations of a plurality of functional units may be physically performed by one component, or the operations of one functional unit may be physically performed by a plurality of components. For convenience of explanation, the user apparatus and the base station have been described using functional block diagrams, but such an apparatus may be realized in hardware, software, or a combination thereof. Software operated by a processor included in a user apparatus and software operated by a processor included in a base station according to the embodiment of the present invention are random access memory (RAM), flash memory, read-only memory (ROM), EPROM, and EEPROM. , A register, a hard disk (HDD), a removable disk, a CD-ROM, a database, a server, or any other suitable storage medium. The present invention is not limited to the above embodiments, and various modifications, modifications, alternatives, substitutions, and the like are included in the present invention without departing from the spirit of the present invention.

UE user apparatus eNB base station 101 UL signal transmission unit 102 DL signal reception unit 103 RRC management unit 104 C-RNTI transmission control unit 201 DL signal transmission unit 202 UL signal reception unit 203 RRC management unit 204 scheduling unit

Claims (10)

A user apparatus that communicates with a base station in a mobile communication system that supports carrier aggregation,
A management unit that receives and holds a terminal identifier for each cell or cell group in the carrier aggregation from the base station;
In a collision type random access procedure executed in a specific cell among a plurality of cells in the carrier aggregation, a message including a terminal identifier associated with the specific cell among terminal identifiers held in the management unit And a transmission unit that transmits to the base station. The user apparatus according to claim 1, wherein the management unit receives a setting message for adding a cell in the carrier aggregation from the base station, and holds a terminal identifier included in the setting message. The message transmitted by the transmitter includes a MAC signal, and the MAC signal stores a terminal identifier associated with the specific cell immediately after the MAC header, and another terminal identification after the terminal identifier. The user apparatus according to claim 1 or 2. When the management unit receives a message including a changed terminal identifier for changing a terminal identifier already held from the base station, the management unit deactivates each cell associated with the terminal identifier. The user apparatus according to any one of claims 1 to 3. The user apparatus according to any one of claims 1 to 4, wherein the management unit notifies the base station of capability information including a number of terminal identifiers that can be set in the user apparatus. 6. When the base station performs cross carrier scheduling for the user apparatus, the user apparatus performs communication using the same terminal identifier in a plurality of cells related to cross carrier scheduling. A user device given in any 1 paragraph. When the base station performs cross carrier scheduling for the user apparatus, the user apparatus performs communication using a terminal identifier associated with each cell in a plurality of cells related to cross carrier scheduling. Item 6. The user device according to any one of Items 1 to 5. The plurality of cells constituting the carrier aggregation are grouped into one or a plurality of cell groups, the same terminal identifier is assigned to each cell in each cell group, and PUCCH is set in at least one cell in each cell group And
The user equipment according to any one of claims 1 to 7, wherein the transmission unit transmits uplink control information of a cell to which the same terminal identifier is assigned using the PUCCH in each cell group. The transmission unit uses the PUSCH when the PUSCH resource exists in a cell having the same terminal identifier as the terminal identifier assigned to the cell at the transmission timing of the uplink control information in a certain cell. The user apparatus according to any one of claims 1 to 8. A terminal identifier notification method executed by a user apparatus that communicates with a base station in a mobile communication system that supports carrier aggregation,
Receiving and retaining a terminal identifier for each cell or cell group in the carrier aggregation from the base station; and
In a collision random access procedure executed in a specific cell among a plurality of cells in the carrier aggregation, a message including a terminal identifier associated with the specific cell among the terminal identifiers held in the step A terminal identifier notification method comprising: transmitting to the base station.

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