JP6867525B2 - User device and terminal identifier notification method - Google Patents

Description

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

In the LTE system, carrier aggregation (CA: Carrier Aggregation) is adopted in which communication is performed using a plurality of carriers at the same time 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), which is a highly reliable cell that guarantees connectivity, and a SCell (Secondary cell), which is an ancillary cell, are set for the user apparatus UE. The user apparatus UE can first connect to the PCell and add the SCell if necessary. The PCell is a cell similar to a single cell that supports RLM (Radio Link Scheduling), SPS (Semi-Persistent Scheduling), and the like.

The addition and deletion of SCell is performed by RRC (Radio Resource Control) signaling. Since the SCell is in the inactive state (deactive state) immediately after being set for the user apparatus UE, it is a cell that can communicate (schedulable) for the first time when it is 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. In addition, Rel. In 10 CAs, for example, as shown in FIG. 2, by bundling a maximum of 5 CCs, a high-speed data rate is realized by widening the bandwidth.

Rel. In 12, dual connectivity (double connection) is introduced, which realizes high throughput by performing simultaneous communication using CCs under different base stations eNB. In Dual connectivity, the UE communicates using the 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 (carrier aggregation between base stations), and Master-eNB (MeNB) and Secondary-eNB (SeNB) are introduced.

In DC, the cell group composed of cells under MeNB (one or more) is MCG (Master Cell Group, master cell group), and the cell group composed of cells under SeNB (one or more) is SCG (one or more). It is called Secondary Cell Group (secondary cell group). The MCG has a PCell and can also have a SCell. The SCG includes one or more SCells, and at least one SCell of the SCGs is set to CC of UL, and one of them is set to PUCCH. This SCell is called a 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. For CAs up to 12, the maximum number of CCs that can be configured per UE is 5.

On the other hand, Rel. In LTE 13, 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, the limit of 5 CCs bundled in CA is limited. The CA enhancement to take is being considered. For example, a CA that bundles up to 32 CC (= 640 MHz) is being studied (Non-Patent Document 1). As an example, FIG. 3 shows an example of bundling 32CCs.

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, the base station eNB transmits the allocation information masked by the C-RNTI assigned to the user apparatus UE to the user apparatus UE in the RRC connection state, and the user apparatus UE uses its own C-RNTI. Decrypt the allocation information.

Further, in the user device UE in the RRC connection state, for example, when uplink data is generated from a state where there is no communication, the user device UE executes a collision-type random access (CBRA) to execute an uplink resource. To be assigned.

FIG. 4 shows a CBRA procedure between the user equipment UE and the base station eNB. The user apparatus UE transmits the 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 C-RNTI assigned to itself to the base station eNB (step 3). The base station eNB identifies by the C-RNTI that the user equipment UE is a user equipment UE connected to the RRC, and for example, a PDCCH containing uplink resource allocation information masked by the C-RNTI is used as the user equipment. Send to the UE (step 4). The user device UE recognizes that the random access was successful (Contention resolution) without collision because the uplink resource allocation information could be acquired by C-RNTI, and the next uplink transmission is performed based on the uplink resource allocation information. Execute.

Rel. In CAs up to 12, it is stipulated that the same C-RNTI is used for all PCells and SCells set in the user apparatus UE (Non-Patent Document 2). On the other hand, as described above, when expanded to 32CC, it is assumed that it is not easy to secure the same C-RNTI in all 32 cells. That is, if the same C-RNTI is used in all 32 cells, there is a high possibility that a cell in which a C-RNTI collision occurs between UEs will occur. If C-RNTI is reserved in advance so as to avoid this, a shortage of C-RNTI may occur. Therefore, in 32CC, it is assumed that a plurality of C-RNTIs are assigned to the UE. FIG. 5 shows an example in which a plurality of C-RNTIs are assigned in CA. In the example of FIG. 5, different C-RNTIs are assigned to each cell group (CG) constituting CA.

In the conventional LTE, since the user apparatus UE always has only one C-RNTI, the C-RNTI already assigned in Msg3 of the CBRA described with reference to FIG. 4 is reported to the base station eNB ( Non-Patent Document 3).

As described above, when there are a plurality of C-RNTIs, there is no provision as to how the 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 carries out CA by cell # A and cell # B. UE2 is assigned C-RNTI # Y to cell # A and C-RNTI # X to cell # B.

In the CBRA, the UE 1 reports C-RNTI # X to the eNB 10 in cell # A, and the UE 3 reports C-RNTI # Y to the eNB 10 in cell # B. As described above, there is no specification of the C-RNTI reporting method of UE2, 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 eNB 10.

In this case, the eNB 10 cannot identify whether C-RNTI # X belongs to UE1 or UE2, and cannot identify whether C-RNTI # Y belongs to 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 device and a base station communicate using carrier aggregation, when a plurality of terminal identifiers are assigned to the user device, the base station is used. An object of the present invention is to provide a technique for a user device to notify a base station of a terminal identifier so that the user device can be properly identified.

According to embodiments of the present invention
A management unit that receives and holds terminal identifiers for each cell group from the base station,
In the collision type random access procedure performed in a particular cell included before SL cell groups among the terminal identifier stored in the management unit, said base message comprising a terminal identifier associated with the particular cell and a transmission unit for transmitting to the station,
The message transmitted by the transmitter does not include a terminal identifier that is not associated with the particular cell.
When the management unit receives a message from the base station including the changed terminal identifier for changing the already held terminal identifier, the management unit obtains a cell associated with the already held terminal identifier. A user device to be inactive is provided.

Further, according to the embodiment of the present invention, it is a terminal identifier notification method executed by the user device.
The step of receiving and holding the terminal identifier for each cell group from the base station ,
In a collision-type random access procedure executed in a specific cell included in the cell group, a message including a terminal identifier associated with the specific cell among the terminal identifiers held in the step is sent to the base station. With steps to send
With
The message transmitted in the transmitting step does not include a terminal identifier that is not associated with the particular cell.
In the step of receiving and holding, when a message including the changed terminal identifier for changing the already held terminal identifier is received from the base station, it is associated with the already held terminal identifier. the resulting cell terminal identifier notification method for the inactive state is provided.

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

Rel. It is a figure for demonstrating 10 CAs. 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 the collision type random access. It is a figure which shows the example of the case where a plurality of C-RNTIs are assigned in CA. It is a figure for demonstrating a problem. It is a block diagram of the system in Embodiment of this invention. It is a figure for demonstrating the processing procedure 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 an example of the transmission method of C-RNTI. It is a figure for demonstrating an example of the transmission method of C-RNTI. It is a figure which shows the whole operation image. It is a figure which shows the procedure example at the time of changing C-RNTI other than C-RNTI of PCell. It is a figure for demonstrating the notification method of an Aptitude. 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 an example of 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.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted 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. Although the present embodiment targets an LTE mobile communication system, the present invention is not limited to LTE and can be applied to other mobile communication systems that employ carrier aggregation.

Further, in the following, a cell group (CG) composed of a plurality of cells constituting the CA is used. MCG and SCG in DC are examples of CG, but CG is a concept not limited to MCG and SCG, and a group of a plurality of cells grouped from some viewpoint is called CG. Further, CG includes the 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 is composed of only the downlink CC or the downlink CC and the uplink CC. Further, the release of the 3GPP standard of "LTE" in the present specification and claims shall be a release in which CA (including DC) is introduced, but is not limited thereto. Further, in the embodiment described below, the C-RNTI transmission in the CBRA procedure is targeted, but the C-RNTI transmission may be executed by a procedure other than the CBRA procedure.

Further, in the present embodiment, C-RNTI is notified as a terminal identifier, but the terminal identifier to be notified is not limited to C-RNTI.

(Overall system configuration)
FIG. 7 shows a configuration diagram of a communication system according to an 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 equipment UE. In FIG. 7, one base station eNB and one user equipment UE are shown, but this is for convenience of illustration, and a plurality of each may exist.

Further, 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, one or a plurality of RREs (remote wireless devices) connected to the base station eNB by an optical fiber or the like may be provided at a place away from the base station eNB. Further, it may have a dual connectivity configuration including a plurality of base stations eNB. When targeting Dual Connectivity, if the user equipment UE transmits a PRACH at (a cell in) the MCG to initiate the CBRA procedure, the user equipment UE transmits Msg3 to the MeNB and the user equipment UE is at SCG (in). 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 semantically includes such MeNB and SeNB. The CBRA procedure in DC is not limited to this.

In the present embodiment, in order to solve the above-mentioned problems, in the CBRA procedure, the user apparatus UE determines that the C-RNTI associated with the cell that executes the CBRA procedure is set to the base station eNB by Msg3. Hereinafter, the contents of the processing in the present embodiment will be described in more detail.

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

First, in step 101, the base station eNB notifies the user apparatus UE of C-RNTI for each cell (serving cell) constituting the CA. “For each cell” includes the case of notifying C-RNTI for each cell group (CG). This notification is given, for example, by an RRC connection recognition message, but may also be given by a MAC signal or the like.

The user equipment UE and the base station eNB transmit and receive signals using the C-RNTI assigned to each cell with respect to the user equipment UE (step 102). For example, when CA by cell # 1 and cell # 2 is set in the user apparatus UE, C-RNTI # 1 is assigned to cell # 1, and C-RNTI # 2 is assigned to cell # 2, the base is assigned. The station eNB transmits the PDCCH in the cell # 1 using C-RNTI # 1 and the PDCCH in the cell # 2 using the C-RNTI # 2. The user apparatus UE acquires allocation information using C-RNTI # 1 / C-RNTI # 2 in cell # 1 / cell # 2, and transmits or receives data in each cell.

Regarding the notification of C-RNTI, a CA composed of a plurality of cells may be set in the user apparatus UE at a time before step 101, and the C-RNTI may be notified in step 101, or step 101 may be an additional instruction of SCell. Therefore, C-RNTI may be notified in the additional instruction. Further, when step 101 is an additional instruction of the SCell and the C-RNTI is not notified, the user apparatus UE is said that the same C-RNTI as the C-RNTI of the already assigned PCell is assigned to the SCell. You may consider it.

Further, the base station eNB notifies the user apparatus UE of C-RNTI for the SCell to be added every time the SCell is additionally set, for example. Further, for example, while adding SCell, the base station eNB explicitly or implicitly notifies the same C-RNTI as PCell until the number of cells is a predetermined number (example: 16), and the number of cells exceeds the predetermined number. When is set, C-RNTI different from PCell may be explicitly notified. Implicit notification means, for example, not notifying C-RNTI when adding SCell until the number of cells reaches a predetermined number.

Further, in the present embodiment, at least one cell for transmitting PUCCH may be set in the cell group (CG) having the same C-RNTI.

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

FIG. 9B shows an example in which cells for transmitting PUCCH are set one by one in CG having the same C-RNTI. Specifically, PUCCH transmission is possible in cell # 3 of the CGs (cells # 1 to # 3) to which C-RNTI # 1 is assigned, and CG (cell # 3) to which C-RNTI # 2 is assigned can be transmitted. PUCCH transmission is possible in cell # 6 of (5, cell # 6, ...). PUCCH transmission is possible, for example, means that PUCCH resources are allocated to both ends of the band in the upstream CC of the corresponding cell.

In step 103 of FIG. 8, for example, when the uplink data transmission of the user apparatus UE is interrupted, the uplink data to be transmitted is generated and the CBRA procedure is triggered, so that the user apparatus UE uses the PRACH to transmit the RA preamble. I do.

In step 103, the user apparatus UE that transmitted the PRACH in a certain cell receives the 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 the 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 manages the cell, the C-RNTI, and the UE in association with each other, the C-RNTI included in the Msg3 received in the cell can uniquely identify the user apparatus UE that transmitted the Msg3. After that, the allocation information and the like are transmitted to the specified user apparatus UE.

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

In the first CBRA, the user apparatus UE transmits a PRACH (RA preamble) in the PCell, receives an RA response in the PCell, and transmits Msg3 in the PCell.

In the second CBRA, the user apparatus UE transmits the PRACH in an arbitrary cell, receives the 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, but for example, a cell having good radio quality can be selected to execute the CBRA procedure.

In the first CBRA (CBRA with only PCell), in step 105 of FIG. 8, the user apparatus UE always transmits the Msg3 including the C-RNTI of the PCell.

In the second CBRA (CBRA is possible in any cell), when the user apparatus UE transmits Msg3 in the PCell or the cell associated with the same C-RNTI as the PCell in step 105 of FIG. 8, the C- of the PCell Notify the base station eNB by Msg3 of RNTI.

Further, in step 105 of FIG. 8 in the second CBRA, when the user apparatus UE transmits Msg3 in a cell to which C-RNTI different from PCell is assigned, C-RNTI of the cell is included in Msg3 and sent to the base station eNB. Notice.

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

A specific example is shown in FIG. 10 (a) and 10 (b) show a state in which the base station eNB sets a CA composed of PCell and SCell in the user apparatus UE, respectively. FIG. 10A is 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 in the PCell. FIG. 10B is an example in which the CBRA procedure is executed in the SCell. In this case, the user apparatus UE transmits Msg3 including the C-RNTI of the SCell in the SCell. In the example of FIG. 10B, for example, when the same C-RNTI as the PCell is assigned to the SCell, the user apparatus UE transmits Msg3 including the C-RNTI of the PCell by the SCell.

In the above example, the user apparatus UE includes one C-RNTI in Msg3 for transmission, but may include a plurality of C-RNTIs in Msg3 for transmission. 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-RNTIs assigned to the UE are 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 the 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 by referring to the C-RNTIs stored immediately after the MAC header. When a plurality of C-RNTIs are included in Msg3, storing the C-RNTIs to be referred to immediately after the MAC header is only an example. If the base station eNB can specify the C-RNTI to be referred to, the C-RNTI to be referred to may be stored at any position.

FIG. 12 shows an overall operation image of 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 carries out CA by cell # A and cell # B. UE2 is assigned C-RNTI # Y to cell # A and C-RNTI # X 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 the C-RNTI # Y assigned to cell # A to eNB 10 when executing the CBRA procedure in cell # A, and cell # B when executing the CBRA procedure in cell # B. Report the C-RNTI # X assigned to # B to eNB 10. By such a reporting method, the eNB 10 can identify the UE that has accessed in each cell.

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

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

Further, when the user apparatus UE reconnects to the base station eNB, the user apparatus UE autonomously deletes the SCell, so that the C-RNTI of the SCell to be deleted may be released. Since the user apparatus UE includes the C-RNTI of the PCell in the reconnection request message, the C-RNTI of the PCell is held without being released.

In order to change the C-RNTI used for communication by the user apparatus UE 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 the Intra-cell HO is executed, all the cells constituting the CA are deactivated. On the other hand, when the user apparatus UE holds the C-RNTI for each cell (or each CG) constituting the CA as in the present embodiment, all the cells are deactivated by the Intra-cell HO as in the conventional case. That is not desirable.

Therefore, in the present embodiment, when the C-RNTI of the PCell is changed, the Intra-cell HO is performed as before. In this case, all SCells are deactivated. However, SCell to which C-RNTI of PCell is not assigned may not be triggered.

On the other hand, when changing a C-RNTI other than the C-RNTI of the PCell (eg, C-RNTI of the SCell), the base station eNB is changed by the RRC connection resonance that instructs the Intra-cell HO of the SCell. Notify C-RNTI. Upon 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 implements the change of the C-RNTI. In this case, C-RNTI other than C-RNTI to be changed is not affected (deactivated) by the assigned cell.

The latter procedure example of the above C-RNTI change is shown in FIG. As shown in FIG. 13, when the user apparatus UE receives the RRC connection resonance including the changed C-RNTI (step 201), it activates only the target cell (here, SCell) and implements the C-RNTI change. (Step 202). When the processing for the RRC connection resonance is completed, the RRC connection resonance complete is returned (step 203).

(Capacity notification)
In the present embodiment, a plurality of C-RNTIs can be set for one user device UE, but the number of C-RNTIs that can be set depends on the capacity of the user device UE such as memory. .. However, there is no mechanism for notifying the ability 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 procedure for notification of ability. For example, when the user equipment UE makes an RRC connection to the base station eNB, the user equipment UE receives a capability information inquiry (UE Capacity Inquiry) from the base station eNB (step 301), and the user equipment UE can set C-RNTI. The capability information (UE Capacity information) including the number of the above 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 ability of C-RNTI, the number may be explicitly notified as described above, or may be implicitly notified by the number of cells (CC number) that can be set by the user apparatus UE in CA. Good. For example, when the user equipment UE notifies the base station eNB of the number of cells of 6 to 16 cells as the capacity information of the CA, the base station eNB can set up to two C-RNTIs in the user equipment UE. When 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 the user apparatus UE can set up to four C-RNTIs.

(Cross-carrier scheduling)
In CA, it is possible to allocate resources in other cells by PDCCH transmitted from the base station eNB in one cell, and this is called cross carry scheduling (CCS).

In the conventional cross-carry scheduling, the user apparatus UE performs the same C-RNTI for decoding the PDCCH in the scheduling cell, which is the cell to which the PDCCH is transmitted, and the PDSCH in the allocated cell, which is the cell to which the resource allocation is performed by scheduling. Is used. On the other hand, in the case of the present embodiment in which the C-RNTI may differ between the scheduling cell and the allocated cell, decoding is performed using the C-RNTI as in the following method example 1 or method 2.

In Method Example 1, even an allocation cell different from the scheduling cell is decoded by using the scheduling cell C-RNTI. 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 the generation of PDCCH in the scheduling cell and the generation of PDSCH in the allocated cell by using C-RNTI in the scheduling cell in response to the operation of the UE.

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

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

In the above example, the downlink (DL) is taken as an example, but the same applies to the uplink (UL). In UL, for example, when the user equipment UE transmits PUSCH, the scheduling cell C-RNTI is used, or the allocation cell C-RNTI is used.

(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. If there is a PUSCH resource at the timing of UCI transmission, the user equipment UE transmits the UCI by PUSCH. This is called the UCI piggyback. If there is no PUSCH resource at the timing of UCI transmission, UCI is transmitted by PUCCH.

As described above, in the present embodiment, it is possible to set at least one cell for transmitting PUCCH in the cell group having the same C-RNTI (example: FIG. 9B). In this case, for example, each PUCCH is multiplexed with UCIs of cells having the same C-RNTI. Alternatively, the UCIs of all cells may be multiplexed on the PUCCH of the PCell regardless of the C-RNTI.

FIG. 16A shows an example in which UCIs of cells having the same C-RNTI are multiplexed on each PUCCH. As shown in FIG. 16A, the same C-RNTI # 1 is assigned in the CG # 1 composed of the cells # 1 and the cell # 2, and the UCI of the cell # 2 is a cell together with the UCI of the cell # 1. It is transmitted by PUCCH of # 1.

When a plurality of C-RNTIs are set for piggyback of UCI to PUSCH when there is a PUSCH resource at the timing of UCI transmission, there are the following method example 1 and method example 2.

In Method Example 1, the user equipment UE performs UCI piggyback only between cells to which the same C-RNTI is assigned. For example, in the example shown in CG # 2 of FIG. 16A, UCI piggyback is performed only between cells # 3 and 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, and there are multiple PUSCHs in a plurality of cells to which the same C-RNTI is assigned, for example, a user device. The UE multiplexes and transmits UCI to the PUSCH of the cell with the smallest CellIndex among the cells to which the same C-RNTI is assigned. Multiplexing to the cell having the smallest CellIndex is only an example, and the cell may be multiplexed to the cell having the largest CellIndex, or the cell to be multiplexed may be determined by another method.

Further, as shown in FIG. 16B, the user equipment UE may carry out the UCI piggyback on the PUSCH to which a different C-RNTI is assigned. That is, in the example of FIG. 16B, the PUSCH of cell # 3 to which C-RNTI # 2 is assigned is used to transmit the UCI of cell # 1 and cell # 2 to which C-RNTI # 1 is assigned. Has been done.

(UL transmission priority control based on C-RNTI allocation)
In general, uplink transmission resources / uplink transmission power are limited. Therefore, for example, when the signal transmission timings from a plurality of cells overlap, only the signal of a certain cell is transmitted and the transmission of another cell is stopped (Drop), or only the signal of a certain cell is transmitted with normal power. , Scaling the transmission power of other cells.

In the present embodiment, the above-mentioned Drop / Scaling control 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 to the priority of the UL transmission in the other SCell. Implement control that is higher than the degree.

More specifically, for example, in the user equipment UE, when the transmission of CSI (Channel State Information) such as CQI (example: periodic transmission) is set for each cell, the user equipment UE is the same as the PCell. If the CSI transmission timing of the cell having C-RNTI and the cell not having C-RNTI overlaps, the latter CSI is dropped. Further, for example, when the UL transmission timing of the cell having the same C-RNTI as the PCell and the UL transmission timing of the cell that does not overlap with each other, the user apparatus UE preferentially scales or drops the latter UL transmission. ..

(Device configuration example)
Next, the 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, FIG. 18 shows a functional configuration diagram of the user apparatus UE according to the present embodiment. As shown 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 the functional parts particularly related to the embodiment of the present invention in the user apparatus UE, and also has at least a function (not shown) for performing LTE-compliant operation. Further, the functional configuration shown in FIG. 18 is only an example. Any function classification or name of the functional unit may be used as long as the operation according to the present embodiment can be executed.

The UL signal transmission unit 101 includes a function of generating various signals of the physical layer from the signals of the upper layer to be transmitted from the user apparatus UE and wirelessly transmitting them. The DL signal receiving unit 101 includes a function of wirelessly receiving various signals from the base station eNB and acquiring a signal of a higher layer from the received signal of the physical layer. The UL signal transmitting unit 101 and the DL signal receiving unit 102 each include a function of executing a CA that bundles a plurality of CCs for communication.

It is assumed that the UL signal transmitting unit 101 and the DL signal receiving unit 102 each 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 transmitting unit 101 and the DL signal receiving unit 102 can execute communication by cross-carrier scheduling, UCI transmission, UL transmission priority control, and the like described above.

The RRC management unit 103 includes a function of transmitting and receiving RRC messages to and from the base station eNB, and processing such as setting / changing / managing CA information and configuration change. Further, the RRC management unit 103 includes a storage means for receiving the C-RNTI allocation for each cell (for each CG) from the base station eNB and holding the C-RNTI. In addition, the RRC management unit 103 also includes a function of holding information on the capacity of the user equipment UE and notifying the base station eNB of the information on the capacity. Further, the RRC management unit 103 includes a function of releasing and changing the C-RNTI.

The C-RNTI transmission control unit 104 controls transmission of the C-RNTI according to the present embodiment to the 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 include in and send. 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 shown in FIG. 19, the base station eNB includes a DL signal transmitting unit 201, a UL signal receiving unit 202, an RRC management unit 203, and a scheduling unit 204. FIG. 19 shows only the functional parts particularly related to the embodiment of the present invention in the base station eNB, and also has at least a function (not shown) for performing LTE-compliant operation. Further, the functional configuration shown in FIG. 19 is only an example. Any function classification or name of the functional unit may be used as long as the operation according to the present embodiment can be executed.

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

It is assumed that the DL signal transmitting unit 201 and the UL signal receiving unit 202 each include a packet buffer and perform layer 1 (PHY) and layer 2 (MAC, RLC, PDCP) processing (however, this is limited). Not possible).

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

The scheduling unit 204 performs scheduling for each cell to the user apparatus UE that executes CA, creates PDCCH allocation information using C-RNTI by the method described above, and transmits PDCCH including the allocation information. It includes a function of instructing the DL signal transmission unit 201.

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 the RRC connection state, CA is set, and C-RNTI is assigned to each cell constituting CA.

For example, when uplink data is generated in the user apparatus UE, the UL signal transmission unit 101 of the user apparatus UE activates the CBRA (collision type RA) procedure (step 401) and transmits the RA preamble in the cell #A (step). 402). The user apparatus UE receives the RA response in 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 steps 402, 403, etc., and includes the C-RNTI corresponding to the cell #A in Msg3. Instruct the UL signal transmission unit 101 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 embodiments)
As described above, the present embodiment includes a management unit that receives and holds a terminal identifier for each cell or cell group in the carrier aggregation from the base station, and the management unit has already held the terminal identifier. Provided is a user apparatus for deactivating the cell associated with the already held terminal identifier when a message including the changed terminal identifier for changing the existing terminal identifier is received from the base station. To. In this configuration, a message including the terminal identifier associated with the specific cell is transmitted to the base station. Therefore, when a plurality of terminal identifiers are assigned to the user device, the base station has accessed the user device. 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, the terminal identifier can be notified in the setting message for adding a cell, so that the number of signalings can be reduced.

In a collision-type random access procedure executed in a specific cell included in the cell group, a message including a terminal identifier associated with the specific cell among the terminal identifiers held in the management unit is sent to the base station. 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. Another terminal identification may be stored after the terminal identifier. With this configuration, the base station can identify the user device by referring to the terminal identifier (predetermined storage position) immediately after the MAC header.

When the management unit receives a message from the base station including the changed terminal identifier for changing the already held terminal identifier, the management unit deactivates each cell associated with the terminal identifier. It may be that. In this configuration, when the terminal identifier is changed, the cell that is not associated with the terminal identifier can be not affected, and the terminal identifier can be changed without affecting the 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 the allocation of the terminal identifiers according to the number.

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

When the base station executes cross-carrier scheduling for the user device, the user device communicates with a plurality of cells related to the cross-carrier scheduling using a terminal identifier associated with each cell. May be. In this configuration, it is not necessary for the base station side to link the terminal identifiers between cells, which simplifies the scheduling process.

A plurality of cells may be grouped into one or a plurality of the cell groups, the same terminal identifier may be assigned to each cell in each cell group, and PUCCH may be set to at least one cell in each cell group. In this case, for example, the transmission unit transmits the uplink control information of the cell to which the same terminal identifier is assigned by using the PUCCH in each cell group. With this configuration, the PUCCH to which the uplink control information of each cell should be transmitted is clearly defined, so that the uplink control information can be accurately transmitted.

When the transmission unit has a PUSCH resource 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 cell, the transmission unit uses the PUSCH to transmit the uplink control information. It may be transmitted. With this configuration, the PUSCH to which the uplink control information of each cell should be transmitted is clearly defined, so that the uplink control information can be accurately transmitted.

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

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

(Additional note)
The embodiment described above can be further described as the following appendix.
(Appendix 1)
A user device that communicates with a base station in a mobile communication system that supports carrier aggregation.
A management unit that receives and holds terminal identifiers 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 the terminal identifiers held in the management unit. A user device including a transmission unit that transmits the above to the base station.
(Appendix 2)
The user device according to Appendix 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.
(Appendix 3)
The message transmitted by the transmission unit includes a MAC signal, in which a terminal identifier associated with the specific cell is stored immediately after the MAC header, and another terminal identification is performed after the terminal identifier. The user device according to Appendix 1 or 2, wherein the device is stored.
(Appendix 4)
When the management unit receives a message from the base station including the changed terminal identifier for changing the already held terminal identifier, the management unit deactivates each cell associated with the terminal identifier. The user device according to any one of Appendix 1 to 3.
(Appendix 5)
The user device according to any one of Appendix 1 to 4, wherein the management unit notifies the base station of capability information including the number of terminal identifiers that can be set in the user device.
(Appendix 6)
When the base station executes cross-carrier scheduling for the user device, the user device communicates using the same terminal identifier in a plurality of cells related to the cross-carrier scheduling. The user device according to item 1.
(Appendix 7)
When the base station executes cross-carrier scheduling for the user device, the user device communicates with a plurality of cells related to the cross-carrier scheduling using a terminal identifier associated with each cell. The user device according to any one of 1 to 5.
(Appendix 8)
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 to at least one cell in each cell group. And
The user device according to any one of Supplementary note 1 to 7, wherein the transmission unit transmits uplink control information of a cell to which the same terminal identifier is assigned by using the PUCCH in each cell group.
(Appendix 9)
When the transmission unit has a PUSCH resource 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 cell, the transmission unit uses the PUSCH to transmit the uplink control information. The user device according to any one of Appendix 1 to 8 to be transmitted.
(Appendix 10)
A terminal identifier notification method executed by a user device that communicates with a base station in a mobile communication system that supports carrier aggregation.
A step of receiving and holding 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 the terminal identifiers held in the step is displayed. A terminal identifier notification method including a step of transmitting to the base station.

Although the embodiments of the present invention have been described above, the disclosed inventions are not limited to such embodiments, and those skilled in the art can understand various modifications, modifications, alternatives, substitutions, and the like. There will be. Although explanations have been given using specific numerical examples in order to promote understanding of the invention, these numerical values are merely examples and any appropriate value 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, and the items described in one item may be used in combination with another item. It may be applied (as long as there is no contradiction) to the matters described in. The boundary of the functional unit or the processing unit in the functional block diagram does not always correspond to the boundary of the physical component. The operation of the plurality of functional units may be physically performed by one component, or the operation of one functional unit may be physically performed by a plurality of components. For convenience of description, user equipment and base stations have been described using functional block diagrams, but such equipment may be implemented in hardware, software, or a combination thereof. The software operated by the processor of the user apparatus and the software operated by the processor of the base station according to the embodiment of the present invention are random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM. , Registers, hard disks (HDDs), removable disks, CD-ROMs, databases, servers and any other suitable storage medium. The present invention is not limited to the above-described embodiment, and various modifications, modifications, alternatives, substitutions, etc. are included in the present invention without departing from the spirit of the present invention.

UE user equipment 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 (8)

A management unit that receives and holds terminal identifiers for each cell group from the base station,
In the collision type random access procedure performed in a particular cell included before SL cell groups among the terminal identifier stored in the management unit, said base message comprising a terminal identifier associated with the particular cell and a transmission unit for transmitting to the station,
The message transmitted by the transmitter does not include a terminal identifier that is not associated with the particular cell.
When the management unit receives a message from the base station including the changed terminal identifier for changing the already held terminal identifier, the management unit obtains a cell associated with the already held terminal identifier. User device to be inactive. The user device according to claim 1, wherein the management unit receives a setting message for adding a cell included in the cell group from the base station, and holds a terminal identifier included in the setting message. The management unit notifies the base station of capability information including the number of terminal identifiers that can be set in the user device.
The user device according to claim 1 or 2. When the base station executes cross-carrier scheduling for the user device, the user device communicates using the same terminal identifier in a plurality of cells related to the cross-carrier scheduling.
The user device according to any one of claims 1 to 3. When the base station executes cross-carrier scheduling for the user device, the user device communicates with a plurality of cells related to the cross-carrier scheduling by using a terminal identifier associated with each cell.
The user device according to any one of claims 1 to 4. A plurality of cells are grouped into one or a plurality of the cell groups, the same terminal identifier is assigned to each cell in each cell group, and PUCCH is set to at least one cell in each cell group.
The transmission unit uses the PUCCH in each cell group to transmit uplink control information of cells to which the same terminal identifier is assigned.
The user device according to any one of claims 1 to 5. When the transmission unit has a PUSCH resource 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 cell, the transmission unit uses the PUSCH to transmit the uplink control information. Send
The user device according to any one of claims 1 to 6. The step of receiving and holding the terminal identifier for each cell group from the base station ,
In a collision-type random access procedure executed in a specific cell included in the cell group, a message including a terminal identifier associated with the specific cell among the terminal identifiers held in the step is sent to the base station. With steps to send
With
The message transmitted in the transmitting step does not include a terminal identifier that is not associated with the particular cell.
In the step of receiving and holding, when a message including the changed terminal identifier for changing the already held terminal identifier is received from the base station, it is associated with the already held terminal identifier. terminal identifier notification method for the obtained cells inactive state.

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