KR102046325B1 - Apparatus and method for transmitting signal in a mobile communication system - Google Patents

Abstract

The present invention relates to an apparatus and method for transmitting a signal using a plurality of carriers in a mobile communication system.
To this end, when an event requiring backward transmission to a plurality of serving cells occurs at the same time, a transmission rule defined for a classification condition corresponding to configuration information of the plurality of serving cells is applied among the plurality of transmission rules defined for each predetermined classification condition. A signal is transmitted to at least one serving cell of the plurality of serving cells.

Description

Apparatus and method for transmitting signal in mobile communication system {APPARATUS AND METHOD FOR TRANSMITTING SIGNAL IN A MOBILE COMMUNICATION SYSTEM}

The present invention relates to an apparatus and method for transmitting a signal in a mobile communication system, and more particularly, to an apparatus and method for transmitting a signal using a plurality of carriers.

The mobile communication system was developed to provide a communication service while securing user mobility. Although the mobile communication system initially provided a voice call-oriented service, the development of communication technology has led to the provision of a high-speed data communication service.

Recently, technology has been developed from 3GPP (3rd Generation Partnership Project) system, which is one of the next generation mobile communication systems, to Long Term Evolution (LTE) system. In particular, LTE technology has made it possible to provide a high-speed packet-based communication service supporting a transmission rate of up to 100 Mbps.

In addition, recently, a discussion about an advanced LTE (LTE-Advanced, LTE-A) system incorporating a new technology for improving the transmission speed to the LTE system has been in full swing. Representative technologies newly introduced for this purpose include a carrier aggregation technology.

In the carrier aggregation technology, a user equipment (UE) transmits / receives signals using only one forward carrier and one reverse carrier, but transmits / receives signals using a plurality of forward carriers and a plurality of backward carriers. Receive technology. For example, in the LTE-A system, application to an intra-ENB carrier aggregation technology has been discussed.

However, the carrier aggregation technology in the base station discussing the application to the LTE-A system may lead to a reduction in the availability of the carrier integration technology. In particular, in a communication system in which a plurality of pico cells and one macro cell are overlapped with each other, carrier aggregation technology in a base station may cause a problem of integrating macro and pico cells.

The present invention provides an apparatus and method for inter-ENB carrier aggregation between different base stations in a mobile communication system.

In addition, the present invention provides an apparatus and method for performing reverse transmission by applying an optimal transmission rule in consideration of a base station to which the plurality of cells belong to when the transmission to the plurality of serving cells is required in the mobile communication system.

Also, in the present invention, an apparatus and method for transmitting a signal by different transmission rules according to a configuration type of a primary serving cell (P_Cell) and at least one secondary serving cell (S_Cell) in a mobile communication system To provide.

In addition, the present invention provides an apparatus and method for preferentially transmitting a signal to the primary serving cell in the case of overlapping the reverse transmission interval of the primary serving cell and at least one secondary serving cell controlled by different base stations in the mobile communication system.

In addition, in the present invention, when the primary serving cell controlled by the same base station and the reverse transmission interval of at least one secondary serving cell overlap in the mobile communication system, a signal which is transmitted to the primary serving cell and a signal to be transmitted to the at least one secondary serving cell is relatively important An apparatus and method for transmitting a signal having an attribute are provided.

In the method for transmitting signals to a plurality of serving cells from a user terminal of a mobile communication system according to an embodiment of the present invention, when an event requiring reverse transmission to the plurality of serving cells occurs at the same time, a plurality of transmission rules defined for each classification condition are defined. A signal is transmitted to at least one serving cell among the plurality of serving cells by applying a transmission rule defined for a classification condition corresponding to configuration information of the plurality of serving cells.

In the mobile communication system according to an embodiment of the present invention, when a user terminal that transmits signals to a plurality of serving cells simultaneously generates an event requiring backward transmission to the plurality of serving cells, the user terminal may transmit the signals among the plurality of transmission rules defined for each classification condition. And a transmitter for transmitting a signal to at least one of the plurality of serving cells by applying a transmission rule defined for a classification condition corresponding to configuration information of the plurality of serving cells.

According to the present invention, by integrating carriers between different base stations, an opportunity for a user terminal to transmit high-speed data through carrier aggregation can be increased.

In addition, the effects obtained or estimated by the embodiments of the present invention will be disclosed directly or implicitly in the detailed description of the embodiments of the present invention. That is, various effects estimated according to an embodiment of the present invention will be disclosed in the detailed description to be described later.

1 is a view showing the structure of an LTE system to which the present invention is applied;
2 is a diagram showing a radio protocol architecture in an LTE system to which the present invention is applied;
3 is a diagram illustrating an example in which a user terminal transmits a signal based on carrier aggregation technology in a mobile communication system according to an exemplary embodiment of the present invention;
4 is a diagram illustrating an example in which a user terminal transmits a signal based on carrier aggregation technology between base stations in a mobile communication system according to an exemplary embodiment of the present invention;
5 is a diagram illustrating an example of a signal processing procedure for setting a serving cell in a mobile communication system according to an embodiment of the present invention;
6 illustrates another example of a signal processing procedure for setting a serving cell in a mobile communication system according to an embodiment of the present invention;
FIG. 7 illustrates an example of a Radio Resource Control (RRC) message (hereinafter, referred to as an 'RRC message') used for setting a serving cell in a mobile communication system according to an embodiment of the present invention;
8 is a diagram showing another example of an RRC message used for setting a serving cell in a mobile communication system according to an embodiment of the present invention;
9 is a diagram illustrating examples of a user terminal transmitting / receiving a signal to a serving base station and a mobile base station in a mobile communication system according to an exemplary embodiment of the present invention.
10 is a diagram illustrating an entire signal processing procedure for a user terminal to transmit a signal using a plurality of carriers in a mobile communication system according to an embodiment of the present invention;
11 is a view showing an example of a control flow performed by a user terminal to transmit a signal using a plurality of carriers in a mobile communication system according to an embodiment of the present invention;
12 is a diagram illustrating another example of a control flow performed by a user terminal to transmit a signal using a plurality of carriers in a mobile communication system according to an embodiment of the present invention;
FIG. 13 illustrates an example of overlapping uplink transmission intervals to two serving cells on a time axis for an embodiment of the present invention; FIG.
FIG. 14 is a diagram illustrating operations performed by a user terminal when a reverse transmission interval of two serving cells overlaps according to an embodiment of the present invention; FIG.
15 is a diagram illustrating a control flow for performing random access to a newly added serving cell in a user terminal according to an embodiment of the present invention;
16 illustrates an example of a control flow performed by a user terminal receiving a control message for setting a serving cell according to an embodiment of the present invention;
17 illustrates another example of a control flow performed by a user terminal receiving a control message for setting a serving cell according to an embodiment of the present invention;
18 is a diagram illustrating a control flow performed by a user terminal receiving a reverse grant message according to an embodiment of the present invention;
19 is a view showing the configuration of a user terminal according to an embodiment of the present invention;
20 is a diagram showing the configuration of a base station according to an embodiment of the present invention;
21 illustrates a signal processing procedure according to another embodiment of the present invention;
22 is a diagram illustrating a control flow in a terminal according to another embodiment of the present invention;
23 illustrates a signal processing procedure according to another embodiment of the present invention;
24 illustrates a signal processing procedure according to another embodiment of the present invention;
25 illustrates a signal processing procedure according to another embodiment of the present invention;
26 is a diagram illustrating a control flow of a terminal according to another embodiment of the present invention;
27 is a diagram illustrating a control flow performed by a terminal when an RRC connection process failure due to a forward / reverse imbalance occurs according to an embodiment of the present invention;
28 is a diagram illustrating a control flow performed by a terminal when a scheduling request fails according to another embodiment of the present invention;
29 is a diagram illustrating a signal processing procedure of a terminal and a base station associated with a multi-RCC function according to another embodiment of the present invention;
30 is a diagram illustrating a terminal operation when a radio link fails according to another embodiment of the present invention;
31 is a view for explaining a system information change procedure when using a long DRX cycle;
32 is a diagram illustrating a control flow of a terminal according to another embodiment of the present invention;
33 is a view illustrating an operation in which the UE wakes up before paging reception timing and receives SI information;
34 is a diagram illustrating another operation in which the UE wakes up before paging reception timing and receives SI information;

DETAILED DESCRIPTION Hereinafter, a detailed embodiment of the present invention will present exemplary embodiments for achieving the above-described technical problem. In addition, the names of the entities defined for the convenience of description of the present invention may be used in the same manner. However, the names used for the convenience of description do not limit the rights according to the present invention, and of course, the same or easy changes may be applied to a system having a similar technical background.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 shows a structure of an LTE system to which the present invention is applied.

Referring to FIG. 1, a radio access network of an LTE system includes a next generation base station (evolved Node B, hereinafter referred to as 'ENB, Node B' or 'base station') 105, 110, 115, and 120, and a mobile management entity ( Mobility Management Entity (MME) 125 and Serving Gateway (S-GW) 130. The ENBs 105, 110, 115, and 120 and the S-GW 130 connect user equipment (hereinafter referred to as UE or UE) 135 to an external network.

The ENBs 105, 110, 115, and 120 are connected to the UE 135 by a wireless channel. The ENBs 105, 110, 115, and 120 correspond to the Node Bs that make up the UMTS system, but perform a more complex role than the Node Bs.

LTE systems, for example, service most user traffic over shared channels, including real-time services such as Voice over IP (VoIP) over the Internet Protocol (IP).

Therefore, an apparatus for collecting and scheduling state information such as a buffer state, an available transmit power state, and a channel state of a UE is required, which is handled by the ENBs 105, 110, 115, and 120. In particular, the LTE system uses Orthogonal Frequency Division Multiplexing (OFDM) as a radio access technology in a 20 MHz bandwidth to implement a transmission rate of 100 Mbps.

The UE 135 applies an adaptive modulation & coding (AMC) scheme. The AMC scheme is a technique for determining an optimal modulation scheme and channel coding rate for a channel state.

The S-GW 130 creates or removes data bearers with the external network and the ENBs 105, 110, 115, and 120 under the control of the MME 125. The MME 125 is connected with a plurality of MME 125 to perform various control functions in addition to mobility management for the UE 135.

2 shows a radio protocol structure in an LTE system to which the present invention is applied.

Referring to FIG. 2, each of the radio protocols of the UE and ENB constituting the LTE system is a packet data conversion protocol layer (hereinafter referred to as a 'PDCP layer') 205 and 240, and a radio link control layer ( Radio Link Control Layer, hereinafter referred to as 'RLC layer' (210 and 235), Medium Access Control Layer (MAC) (215 and 230) and Physical Layer (hereinafter referred to as 'PHY layer') (220 and 225) Is done.

The PDCP layers 205 and 240 are in charge of operations such as IP header compression / restore. The RLC layers 210 and 235 reconstruct a PDCP PDU (Packet Data Unit) to an appropriate size to perform an ARQ operation.

The MAC layers 215 and 230 form a connection with various RLC layers and physical layers 220 and 225 constituting one UE. The MAC layers 215 and 230 multiplex RLC PDUs provided from the RLC layers to form a MAC PDU, and transfer the configured MAC PDU to the physical layer 220 and 225. The MAC layers 215 and 230 demultiplex the MAC PDUs provided from the physical layers 220 and 225 to extract RLC PDUs, and deliver the extracted RLC PDUs to various RLC layers.

The physical layers 220 and 225 channel-code and modulate higher layer data to generate an OFDM symbol, and transmit the generated OFDM symbol to a wireless channel. The physical layers 220 and 225 perform demodulation and channel decoding on OFDM symbols received through a wireless channel and transmit the demodulation and channel decoding to the upper layer.

3 illustrates an example in which a user terminal transmits a signal based on carrier aggregation technology in a mobile communication system according to an exemplary embodiment of the present invention. It can be seen that the signal transmission example shown in FIG. 3 is a carrier aggregation technology for one base station.

Referring to FIG. 3, one base station 305 transmits a signal to the UE 330 using multiple carriers over several frequency bands, and receives a signal from the UE 330 using the multiple carriers.

For example, a base station 305 using multiple carriers whose forward center frequency consists of f1 315 and f3 310 generally transmits and receives a signal with one UE 330 using one of the multiple carriers. . However, the UE 330 having carrier aggregation capability may transmit signals using multiple carriers.

Accordingly, the base station 305 may increase the transmission speed of the UE 330 by allocating more carriers to the UE 330 having carrier aggregation capability according to a situation. As described above, integrating forward and reverse carriers transmitted or received by one base station 305 is referred to as 'carrier aggregation in a base station'.

However, in some cases, 'carrier aggregation between base stations' may be required, in which forward and reverse carriers are transmitted and received by different base stations.

4 illustrates an example in which a user terminal transmits a signal based on carrier aggregation technology between base stations in a mobile communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the first base station 405 transmits and receives a signal with the UE 430 in the first service area 410 using a carrier having a center frequency f1. The second base station 415 transmits and receives a signal with the UE 430 in the second service area 420 using a carrier whose center frequency is f2.

In this case, when the UE 430 integrates a carrier having a forward center frequency of f1 and a carrier having a forward center frequency of f2, the UE 430 may obtain a result of integrating carriers transmitted and received from one or more base stations. This is called carrier aggregation between base stations.

Hereinafter, terms to be frequently used in defining the embodiments of the present invention are defined.

Carrier aggregation may be understood that a terminal transmits and receives signals through several cells at the same time, assuming that one forward carrier and one reverse carrier transmitted and received by one base station constitute one cell. In this case, the maximum transmission rate is increased in proportion to the number of carriers integrated.

In the following description, when a UE receives a signal on any forward carrier or transmits a signal on any reverse carrier, it is necessary to provide a control channel and a data channel provided by a cell corresponding to a center frequency and a frequency band that characterize the carrier. It includes the meaning of transmitting and receiving signals or data using.

Meanwhile, in the following description, "carrier aggregation" will be expressed as a plurality of serving cells. In this case, the plurality of serving cells has a meaning including a primary serving cell (hereinafter referred to as 'P_Cell') and a secondary serving cell (hereinafter referred to as 'S_Cell').

In addition, in the following description, the terms primary set and non-primary set are used. The primary set refers to a set of serving cells controlled by a base station (hereinafter referred to as a 'reference base station') that controls P_Cell. The non-primary set refers to a set of serving cells controlled by a base station (hereinafter referred to as an "secondary base station") rather than a reference base station controlling P_Cell. For example, the primary set is composed of one P_Cell and at least one S_Cell, and the non-primary set is composed of at least one S_Cell.

On the other hand, for the above, the base station should be able to instruct the terminal whether the predetermined serving cell belongs to the primary set or non-primary set through the process of setting the corresponding serving cell. One terminal may be configured with one primary set and one or more non-primary sets.

In the following description, other terms may be used instead of the primary set and the non-primary set for understanding. For example, terms such as a primary set and a secondary set or a primary carrier group and a secondary carrier group may be used. However, it should be noted that in this case only the terms are different and the meanings are the same.

In addition, terms to be used for the specific description according to an embodiment of the present invention to be described later has the meaning as it is commonly used in the LTE system, the details of which are described in the December 2011 version of TS 36.331 and TS 36.321 See.

5 shows an example of a signal processing procedure for setting a serving cell in a mobile communication system according to an embodiment of the present invention. 5 illustrates a signal processing procedure according to operations of a terminal and a base station for configuring an S_Cell belonging to a primary set.

In particular, FIG. 5 assumes a mobile communication system composed of one UE 505 and two base stations (a first base station 515 and a second base station 510). Here, it is assumed that the first base station is a serving base station (Serving ENB), and the second base station is a mobile base station (Drift ENB).

The primary set for supporting transmission and reception of signals by the serving base station 515 is configured by three cells (Cell 1, 2, 3), and the non-primary set for transmission and reception of signals by the mobile base station. Is composed of two cells (Cell 4, 5). That is, the first, second, and third cells (Cell 1, 2, 3) are controlled by the serving base station 515, and the fourth, fifth cells (Cell 4, 5) are controlled by the mobile base station 510. This is controlled.

It is assumed that the first cell (Cell 1) is P_Cell based on the UE 505 and the remaining cells (Cell 2, 3, 4, 5) are S_Cell. In addition, it is assumed that a second cell (Cell 2) among the S_Cells is newly added S_Cell.

Referring to FIG. 5, the serving base station 515 transmits an RRC message to the UE 505 (step 520). When the RRC message is transmitted as a control message for reestablishing an RRC connection, the RRC message includes information about a new S_Cell, that is, a second cell.

Table 1 below shows an example of information included for each cell in a transmitted RRC message for resetting an RRC connection.

name Explanation S_CellIndex-r10 An identifier of a serving cell, which is an integer having a predetermined size. It is used to update the information of the corresponding serving cell in the future. cellIdentification-r10 Information that physically identifies the serving cell and consists of a forward center frequency and a physical cell id (PCI). radioResourceConfigCommonS_Cell-r10 The information related to the radio resource of the serving cell includes, for example, forward bandwidth, forward HARQ feedback channel configuration information, reverse center frequency information, reverse bandwidth information, and the like. radioResourceConfigDedicatedS_Cell-r10 Information related to a dedicated resource allocated to the terminal in the serving cell includes, for example, reference signal structure information for channel quality measurement, intercarrier scheduling configuration information, and the like. TAG (Timing Advance Group) information Information indicating which TAG a terminal belongs to. For example, it may be configured with a TAG id and a timer (TA). If the terminal belongs to the P-TAG, this information is not signaled.

In Table 1, TAG (Timing Advance Group) information is defined. The TAG means a set of serving cells that share the same backward transmission timing. For example, TAG includes P-TAG (Primary TAG) and S-TAG (Secondary TAG). The P-TAG is a TAG composed of a P_Cell and at least one S_Cell, and the S-TAG is a TAG composed of at least one S_Cell instead of a P_Cell.

Therefore, the fact that any serving cell belongs to a specific TAG means that the backward transmission timing of the arbitrary serving cell is the same as the backward transmission timing of another serving cell belonging to the specific TAG. In general, a TA timer can determine whether backward synchronization between serving cells belonging to a specific TAG.

For example, the backward transmission timing for any TAG may be established by performing a random access procedure in a serving cell belonging to the arbitrary TAG, and may be maintained by receiving a TA command. To this end, whenever the UE receives a TA command for a certain TAG, the UE drives or restarts the TA timer of the corresponding TAG. On the other hand, when the TA timer expires, the UE determines that the reverse transmission synchronization of the corresponding TAG is lost and does not perform backward transmission until random access is performed again.

The UE 505 transmits a response message to the serving base station 515 in response to the RRC message received from the serving base station 515 (step 525). After the UE 50 transmits a response message to the serving base station 515, it establishes forward synchronization for a first S_Cell (ie, cell 2) (S530). For example, when the UE establishes forward synchronization for an arbitrary cell, it means acquiring a forward channel transmission interval by acquiring a synchronization channel of the arbitrary cell.

The serving base station 515 transmits a MAC layer control command to activate the first S_Cell in which the configuration is completed, to the UE 505 at any time when it is determined that the UE 505 has completed the configuration for the first S_Cell. (Step 535). For example, the MAC layer control command may be an Activate / Deactivate MAC Control Element (hereinafter referred to as 'A / D MAC CE').

For example, the MAC layer control command may be configured as a bitmap in which each bit corresponds to a unique S_Cell. For example, in the bitmap constituting the MAC layer control command, the first bit corresponds to the first S_Cell, and the second bit The n-th bit corresponds to the n-th S_Cell. Each bit constituting the bitmap indicates activation or deactivation of the corresponding S_Cell.

The UE 505 starts monitoring the physical control channel of the first S_Cell after a predetermined period has elapsed based on the time point at which the activation command for the first S_Cell is received. The physical control channel for starting the monitoring may be a Physical Dedicate Control Channel (PDCCH) that provides forward and reverse transmission resource allocation information.

If the first S_Cell belongs to a TAG that has already been synchronized, the UE may start forward and backward transmission / reception from the time point at which the activation command for the first S_Cell is received.

However, if the first S_Cell belongs to a TAG that is not synchronized, the UE 505 starts receiving a forward signal only when receiving an activation command for the first S_Cell and does not transmit a reverse signal. Do not. That is, the UE 505 receives forward data when receiving forward transmission resource allocation information through the PDCCH. However, the UE 505 ignores the backward transmission resource allocation information through the PDCCH. That is, if the S_Cell receiving the activation command belongs to a TAG which is not synchronized, the UE 505 starts transmitting / receiving data until receiving a 'random access command' from a predetermined S_Cell belonging to the corresponding TAG through the PDCCH. Wait without. In this case, the random access command is a case where a setting value is recorded in a predetermined field constituting reverse transmission resource allocation information, and instructs a predetermined serving cell to transmit a designated preamble. For example, an identifier of a serving cell to perform preamble transmission may be indicated in a field called a carrier indicator field (CIF) of a random access command.

The UE 505 receives a random access command instructing to transmit a random access preamble from the first S_Cell (step 540). Upon receiving the random access command, the UE 505 transmits a preamble received from the first S_Cell (step 545). The UE 505 then monitors the PDCCH to be sent from the P_Cell to receive a Random Access Response (RAR) message, which is a response message to the preamble. The RAR message includes a TA command and other control information.

For example, if the cell to which the UE 505 transmits a preamble is a cell controlled by a serving base station, P_Cell responds to the preamble in various ways. That is, since RAR reception is performed only in the P_Cell, the PDCCH monitoring load of the UE can be reduced.

When the UE 505 receives a valid response message from the P_Cell, the UE 505 determines that backward signal transmission is possible after a predetermined period has elapsed based on the time at which the response message is received. For example, if a valid RAR is received in subframe n, backward transmission is considered to be possible starting from subframe (n + m).

6 shows another example of a signal processing procedure for setting a serving cell in a mobile communication system according to an embodiment of the present invention. 6 illustrates operations of the UE and the base station for configuring the S_Cell belonging to the non-primary set.

Referring to FIG. 6, the serving base station 615 determines to add an S_Cell to the UE 605 at any point in time. In particular, if the UE 605 is located in an area of a cell controlled by the mobile base station 610, the serving base station 610 is a cell controlled by the mobile base station 610, that is, a fourth and fifth cell (Cell 4, 5). It is determined to add the S_Cell to the UE 605 (step 620).

The serving base station 615 transmits a control message requesting the addition of the S_Cell to the mobile base station 610 according to the above determination (step 625).

Table 2 below defines the information included in the control message to request the addition of S_Cell.

name Explanation S_Cell id information Information related to identifiers of S_Cells to be set in the mobile base station. It consists of one or more S_CellIndex-r10. The serving base station determines and informs the mobile base station in order to prevent reuse of an identifier already in use at the serving base station. TAG id information Information related to the identifier of the TAG to be set in the mobile base station. The serving base station determines and informs the mobile base station in order to prevent reuse of an identifier already in use at the serving base station. Reverse Scheduling Information It consists of priority information and logical channel group information of logical channels configured in the terminal. The mobile base station uses this information to interpret the buffer status report information of the terminal and perform reverse scheduling. Data transfer rate related information The forward / reverse estimated data transmission rate information of the terminal. The mobile base station uses this information to determine whether to reject or reject the S_Cell addition request.

When the mobile base station 610 receives the control message requesting the S_Cell addition from the serving base station 615, the mobile base station 610 determines whether to accept the request in consideration of the current load situation. If it is determined to accept the S_Cell addition request, the mobile base station 610 transmits a response message to the serving base station 615 (step 630).

Table 3 below defines information included in a response message transmitted from the mobile base station 610 to the serving base station 615.

name Explanation S_CellToAddMod Information related to the S_Cells configured in the mobile base station, and consists of the following information. S_CellIndex-r10, cellIdentification-r10, radioResourceConfigCommonS_Cell-r10, radioResourceConfigDedicatedS_Cell-r10, TAG Related Information PUCCH information for PUCCH S_Cell PUCCH (Physical Uplink Control Channel) is configured in at least one S_Cell among the S_Cells belonging to the non-primary set. Through the PUCCH, backward control information such as HARQ feedback, channel status information (CSI), sounding reference signal (SRS), or scheduling request (SR) is transmitted. Hereinafter, the S_Cell through which the PUCCH is transmitted is called a PUCCH S_Cell. Identifier information and PUCCH configuration information of the PUCCH S_Cell are sub-information of this information. Information for data forwarding Information of a logical channel (or logical tunnel) to be used for data exchange between a serving base station and a mobile base station, and includes information such as a GTP (GPRS Tunnel Protocol) tunnel identifier for forward data exchange and a GTP tunnel identifier for reverse data exchange. . Identifier of the terminal The UE is a C-RNTI to be used in the S_Cell of the non-primary set.

When the serving base station 615 receives the response message from the mobile base station 610, the serving base station 615 generates and transmits an RRC control message indicating the addition of the serving cell to the UE 605 (step 635).

Table 4 below defines information included in an RRC control message transmitted by the serving base station 615 to the UE 605.

name Explanation S_CellAddMod Information transmitted by the mobile base station is stored as it is. That is, the same information as S_CellAddMod of Table 3. One S_CellAddMod is stored per S_Cell, and the information is sub-information of S_CellAddModList. PUCCH information for PUCCH S_Cell Information transmitted by the mobile base station is stored as it is. That is, the same information as the PUCCH information for PUCCH S_Cell of Table 3. Non-primary S_Cell List Information about S_Cells belonging to the non-primary set among the S_Cells set. It may be identifiers of the S_Cells or identifiers of TAGs belonging to a non-primary set. Identifier of the terminal The UE is a C-RNTI to be used in the serving cell of the non-primary set.

Configuration information of a plurality of S_Cells may be stored in the RRC control message. In addition, the serving cell of the primary set and the serving cells of the non-primary set may be configured together.

For example, if a second cell, a third cell, a fourth cell, and a fifth cell are set to S_Cell for a UE whose first cell is a P_Cell, the information defined in Table 4 is included in various orders in the RRC control message. Can be deployed.

An example of this is shown in FIG. 7. That is, FIG. 7 shows an example of an RRC message used for setting a serving cell in a mobile communication system according to an embodiment of the present invention.

As shown in Fig. 7, Cell 1 and Cell 2 having the same backward transmission timing constitute a P-TAG. Cell 3 constitutes S-TAG 1, and Cell 4 and Cell 5 constitute S-TAG 2.

The RRC control message includes S_CellToAddModList 705. The S_CellToAddModList 705 includes S_CellToAddMod 710 for Cell 2, S_CellToAddMod 715 for Cell 3, S_CellToAddMod 720 for Cell 4, and S_CellToAddMod 725 for Cell 5.

The S_CellToAddMod 710 may or may not include specific information according to the nature of the S_Cell. For example, if the S_Cell belongs to the P-TAG, that is, has the same backward transmission timing as the P_Cell, the information related to the TAG is not stored in the corresponding S_CellToAddMod. For this reason, information related to TAG is not stored in S_CellToAddMod 710 for Cell 2. S_CellToAddMod (715, 720, 725) for S_Cells belonging to a TAG other than the remaining P-TAG includes an identifier and a TA timer value of the TAG to which the corresponding S_Cell belongs.

Meanwhile, at least one of the cells belonging to the non-primary set stores information related to the non-primary set, for example, an identifier of the non-primary set and a C-RNTI of a terminal to be used in the non-primary set. . In the example of FIG. 7, information 730 related to the non-primary set is stored in S_CellToAddMod 720 for Cell 4. In addition, PUCCH configuration information is stored in one of the cells belonging to the non-primary set. In the example of FIG. 7, the PUCCH configuration information 735 is stored in S_CellToAddMod 720 for Cell 4.

For S_Cells belonging to the non-primary set but without information related to the non-primary set, the non-primary set related information of S_Cell having the same TAG id is applied. For example, the non-primary set related information is not stored in Cell 5, but the non-primary set related information is stored in Cell 4 having the same TAG id. Accordingly, the UE determines that Cell 5 is also a non-primary set, and the non-primary set identifier and C-RNTI of Cell 5 use the same value as that indicated for Cell 4.

8 shows another example of an RRC message used for setting a serving cell in a mobile communication system according to an embodiment of the present invention. That is, FIG. 8 shows another example in which TAG related information and non-primary set related information are stored in a separate location instead of S_CellToAddMod.

Referring to FIG. 8, the RRC control message includes S_CellToAddModList 805. The S_CellToAddModList 805 stores S_CellToAddMod 810 for Cell 2, S_CellToAddMod for Cell 3, S_CellToAddMod for Cell 4, and S_CellToAddMod for Cell 5. The same kind of information is stored in the S_CellToAddMods for each cell. That is, all S_CellToAddMod stores information such as S_CellIndex-r10, cellIdentification-r10, and radioResourceConfigCommonS_Cell-r10.

In addition to the S_CellToAddModList 805, the RRC control message may separately store TAG related information 815, non-primary set related information 820, and PUCCH configuration information of the PUCCH S_Cell.

The TAG related information 815 stores a TAG identifier, identifiers of S_Cells constituting a TAG, and a TA timer value for each TAG. For example, a TAG having a TAG identifier of 1 is composed of S_Cell 2 and has TAG related information 830 that a value of t1 is used as a TA timer. The TAG having the TAG identifier 2 is composed of S_Cell 3 and S_Cell 4, and has TAG related information 835 indicating that a value t2 is used as the TA timer.

The non-primary set related information 820 stores the identifier of the set for each non-primary set, the identifier of the serving cells constituting the set, and the C-RNTI information to be used in the set. For example, a non-primary set having a set identifier of 1 is composed of S_Cell 3 and S_Cell 4, and has information 840 that x is used as a C-RNTI. At this time, the information on the primary set is not signaled separately and is determined based on the <primary set related information determination rule> as follows.

Rules for Determining Information Regarding Primary Sets

The serving cell belonging to the primary set refers to S_Cells not belonging to P_Cell and any non-primary set, and the C-RNTI to be used in the primary set refers to the C-RNTI currently being used in the P_Cell.

The non-primary set related information may include the identifier of the TAG rather than the identifier of the S_Cell. This is possible under the premise that sets and TAGs are configured so that a TAG is not organized over multiple sets. For example, the non-primary set configuration information 820 stores information indicating TAG id 2 instead of information indicating S_Cell 3 and S_Cell 4, and the UE has a non-primary S_Cell 3 and S_Cell 4 belonging to TAG id 2. You can also determine that it is three.

PUCCH configuration information of the PUCCH S_Cell is composed of a non-primary set identifier, an identifier of the PUCCH S_Cell, and PUCCH configuration information. One PUCCH S_Cell exists per non-primary set, and CSI information and HARQ feedback information about serving cells belonging to the non-primary set are transmitted through the PUCCH configured in the PUCCH S_Cell.

Instead of explicitly signaling the identifier of the PUCCH S_Cell, the PUCCH S_Cell may be determined according to a predetermined rule. For example, the S_Cell corresponding to the first S_CellToAddMod of the S_CellToAddModList may be determined as the PUCCH S_Cell. Alternatively, the S_Cell having the highest S_Cell identifier or the S_Cell having the lowest S_Cell identifier may be determined as PUCCH S_Cell among S_Cells in which S_CellToAddMod information is stored in the RRC control message. This tacit decision presupposes that there is only one non-primary set.

The UE 605 transmits a response message corresponding to the RRC control message received from the serving base station 615 to the serving base station 615 (step 640). The UE 605 establishes forward synchronization with newly configured S_Cells (step 645). The UE 605 obtains an SFN (System Frame Number) of the PUCCH S_Cell among newly set S_Cells (step 650). In this case, the SFN acquisition is performed in the process of receiving system information called MIB (Master Information Block). The SFN is an integer between 0 and 1023, increasing by 1 every 10 ms. Accordingly, the UE determines the PUCCH transmission time of the PUCCH S_Cell using the SFN and the PUCCH configuration information. The UE then waits until the S_Cells are activated.

When the mobile base station 610 receives forward data from the serving base station 615 or receives a predetermined control message for activating the S_Cell, the mobile base station 610 starts the procedure of activating the S_Cells (step 655).

For example, the mobile base station 610 transmits an A / D MAC CE to the UE 605 indicating to activate S_Cell 3. If the UE 605 has received the A / D MAC CE in subframe n, it activates S_Cell 3 in subframe n + m1. However, in the subframe (n + m1), since backward synchronization of PUCCH S_Cell is not yet established, both forward / reverse transmission and reception are not possible even though S_Cell 3 is activated. In other words, the UE monitors the PDCCH of the activated S_Cell 3, but ignores the reception of the forward / reverse resource allocation signal.

The mobile base station 610 transmits a random access command to the UE 605 so that the UE 605 establishes reverse synchronization of PUCCH S_Cell (step 665). The UE 605 initiates a random access procedure in PUCCH S_Cell using the dedicated preamble indicated by the random access command. That is, the UE 605 monitors the PDCCH in order to receive a RAR message that is a response message after transmitting the preamble in step S670 of the S_Cell controlled by the mobile base station 610.

If the UE 605 transmits a preamble in the primary set, the RAR message will be sent through P_Cell. However, if the preamble is transmitted in the non-primary set, the UE 605 monitors the PDCCH of the S_Cell or PUCCH S_Cell that transmitted the preamble to receive the RAR message.

This is because additional information exchange is required between the mobile base station 610 and the serving base station 615 in order to process the RAR message in the P_Cell. For example, the RAR message may be received as a C-RNTI for use by the UE 605 in the non-primary set. This is a situation in which the C-RNTI has already been allocated to the UE 605, and since a dedicated preamble is used, there is no possibility of malfunction due to a collision. Therefore, it is more efficient to transmit / receive a response message using the C-RNTI. Because. There is no possibility that the malfunction may occur, because the base station can know which terminal to send the RAR message when receiving the dedicated preamble.

When the UE 605 receives a valid response message from the S_Cell or PUCCH S_Cell that transmitted the preamble, the UE 605 applies a TA command of the response message to adjust the backward transmission timing of the TAG to which the PUCCH S_Cell and the PUCCH S_Cell belong, Enable reverse on. The predetermined time point may be a subframe n + m ₂ when a valid TA command or a valid random access response message is received in the subframe n. Where m ₂ is a predetermined integer.

When one or more serving cells are configured for the UE 605, the UE 605 may be instructed to simultaneously perform reverse transmission on one or more serving cells. In this case, simultaneously performing reverse transmission may cause unexpected side effects depending on the performance or structure of the UE 605.

혹은

등에 원치 않는 간섭이 초래될 수 있다. 하지만 상기 두 주파수의 역방향 전송에 별도의 파원 앰프가 사용된다면, 앞에서의 문제는 발생하지 않을 수 있다. 하지만, 동시 전송으로 인해 전송 출력 부족 문제가 발생할 가능성이 있다.For example, if a UE uses a single power amplifier to simultaneously perform backward transmission in a serving cell having a center frequency of f1 and f2, for example, another frequency related to the two frequencies may be related to a predetermined equation.

or

Unwanted interference may result. However, if a separate power amplifier is used for the reverse transmission of the two frequencies, the above problem may not occur. However, there is a possibility that simultaneous transmission may cause a shortage of transmission output.

In particular, when serving cells controlled by different base stations are configured, the base stations drive a separate scheduler to make a scheduling decision and thus cannot exclude the possibility of simultaneously instructing reverse transmission.

Therefore, it will be said that it is most important to prevent the backward transmission from being performed simultaneously by the UE using one power source amplifier. For this, we can consider applying strict time division scheduling to the primary set and the non-primary set. However, this may not only hamper the scheduling efficiency but also increase the complexity of the terminal.

Therefore, in order to minimize the complexity of the UE while solving the above, a solution based on the following principle may be proposed.

First, if possible, reverse data transmission is performed through the pico cell. That is, the UE performs data transmission and reception through a pico cell in which configuration activation is performed. In this case, if the UE is in the region of the pico cell, transmitting data to the pico cell is not only advantageous for minimizing power consumption of the UE, but also may increase data transmission efficiency.

Secondly, in the case of pico cells, the robustness in the connection can be reduced due to the small area. Therefore, it is desirable to transmit high importance data through the macro cell and to transmit the RRC control message related to mobility control through the macro cell.

As shown in FIG. 4, non-primary sets are typically associated with small cells, such as pico cells, and primary sets are associated with macro cells. Therefore, if the above two principles are met, the UE naturally performs backward transmission mainly through the pico cell. In other words, the possibility of simultaneous backward transmission is significantly reduced.

If a plurality of backward transmissions are indicated at the same time, the UE gives priority to backward transmission of the macro cell that needs more important data transmission. For example, if a time period for performing backward transmission in a macro cell and a time interval for performing backward transmission in a pico cell overlap at least, priority is given to backward transmission of a macro cell that is likely to transmit a relatively important signal.

9 illustrates examples in which a user terminal transmits / receives signals to a serving base station and a mobile base station in a mobile communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 9, when the UE 920 is in an area of a macro cell where propagation of the pico cell does not reach, the UE 920 may store both control plane data 930 and user plane data 925 in the macro cell. It transmits / receives with a base station (ie serving base station) 910 that controls.

The user plane data 925 is processed by the S-GW 905. In this case, a bearer 940 for transmitting / receiving the user plane data is formed between the S-GW 905 and the serving base station 910.

Otherwise, when the UE 920 is located in an area where both radio waves of the pico cell and radio waves of the macro cell arrive, the UE 920 transmits / receives control plane data 937 with the serving base station 910. User plane data 935 transmits / receives with a base station (ie, mobile base station) 915 that controls the pico cell. The bearer 945 for transmitting / receiving the user plane data is formed between the S-GW 905 and the mobile base station 915.

When the UE 920 needs to simultaneously perform reverse transmission for the serving base station 910 and the mobile base station 915, the UE 920 performs only one reverse transmission by applying a predetermined rule and performs the other backward transmission. Does not perform.

10 illustrates an overall signal processing procedure for a user terminal to transmit a signal using a plurality of carriers in a mobile communication system according to an embodiment of the present invention.

Referring to FIG. 10, if a predetermined condition is met in the LTE network, the UE 1005 reports its performance to the serving base station 1010 to the network (step 1025). For example, the predetermined condition may be most representative when a base station requests performance report from a UE.

The performance report message transmitted by the UE 1005 to report its performance to the serving base station 1010 includes the following information.

List of frequency bands supported by the terminal

List of frequency band combinations supported by the terminal

MIMO performance by frequency band combination

In the present invention, along with the information defined above, information indicating whether the simultaneous transmission (or whether the power amplifier is shared) for each frequency band combination supported by the terminal is reported.

In the band combination consisting of the same frequency band, even if the same power amplifier is used or the unnecessary interference problem does not occur or its effect is small, the information defined above is only reported for the combination of different frequency bands among the frequency band combinations. Can be.

If a given terminal supports frequency band A, frequency band B, and supports a frequency band combination as shown in Table 5 below, whether the UE can simultaneously transmit only frequency band combination 3 (or share power amplifier) Report).

Explanation Combination 1 A + A Indicates that a total of two serving cells in frequency band A can be set at the same time Combination 2 B + B Indicates that a total of two serving cells in frequency band B can be set at the same time Combination 3 A + B Indicates that one serving cell in frequency band A and one serving cell in frequency band B can be set at the same time.

For example, if it is reported that simultaneous transmission is possible for the combination 3 shown in Table 5, this means that even if the UE simultaneously performs backward transmission in the serving cell configured in frequency band A and the serving cell configured in frequency band B, This means that no interference occurs with respect to other frequencies having a predetermined relationship with the frequencies of the two serving cells. The UE may report not sharing the power amplifier instead of reporting that simultaneous transmission is possible.

On the other hand, while the UE performs data transmission / reception with the serving base station in the macro cell area, if a predetermined event, for example, an event in which a channel quality of a certain pico cell meets a predetermined criterion occurs, the UE serves. The measurement result message is generated and transmitted to the base station (step 1030).

In this case, the measurement result message may include the following information.

Identifier of a cell whose channel quality meets a predetermined criterion (eg physical layer cell identifier; PCI or Physical Cell Id)

The channel quality of the cell or the signal strength of the reference signal of the cell

When the serving base station 1010 receives the measurement result message from the UE 1005, the serving base station 1010 recognizes that the UE 1005 is in the region of the pico cell. The serving base station 1010 determines to additionally set a pico cell to the UE 1005 (step 1035). Data transmission / reception through the pico cell is in many ways more efficient than transmitting / receiving data through the macro cell. Therefore, if the UE 1005 is located in the region of the pico cell, it is preferable to set to add a new pico cell in which the UE 1005 is located.

The serving base station 1010 identifies the base station 1015 that controls the pico cell with reference to the identifier of the pico cell, and transmits a control message for requesting addition of a serving cell to the checked base station 1015 (step 1040). .

The control message transmitted to request the addition of the serving cell further includes the following information in addition to the information defined in Table 2.

DRB-related information to be serviced through a mobile base station: A DRB (Data Radio Bearer) is a radio bearer configured for user plane data processing. When the terminal enters the pico cell region, it is preferable to process all user plane data or most user plane data through the pico cell. The serving base station informs the mobile base station about DRBs to be processed through the pico cell, for example PDCP configuration information (e.g., PDCP header structure, header compression protocol related information), RLC information (RLC operation mode, various timers, etc.). ), Inform the logical channel related information (logical channel identifier, priority, etc.). The mobile base station determines the final configuration information of the DRB with reference to the information in the future.

Channel information of the serving cell for which additional configuration is requested: The terminal reports the channel quality information reported in the measurement report message to the mobile base station. The mobile base station determines whether the mobile station add request is accepted using this information and data transmission rate related information.

The mobile base station 1015 determines whether to accept or reject the additional request for the serving cell by using channel information of the serving cell, information on a data rate of the terminal, and the like.

If it is determined to accept, the mobile base station 1015 sets up one or more DRBs (step 1045). In the future, the mobile base station 1015 processes data transmitted by the UE 1005 and data to be transmitted to the UE 1005 through the DRB.

Setting the DRB by the mobile base station 1015 is the same as setting a PDCP layer device and an RLC layer device to process a data string requiring a predetermined QoS. The configuration of the DRB may be the same as or different from the original configuration informed by the source base station 1010.

The mobile base station generates a control message for accepting the S_Cell addition request and transmits it to the serving base station 1010 (step 1050). The control message further includes the following information in addition to the information defined in Table 3.

DRB configuration information: If the same as the DRB configuration used in the source base station may be omitted.

List of DRBs to be relocated: DRB relocation is described in more detail below. This information can be omitted if all DRBs are relocated.

Scheduling information processing related information: Information related to scheduling information such as a buffer status report (BSR) and a power headroom report (PHR), for example, a triggering condition or a periodic reporting period. If the same as the information of the source base station can be omitted.

The serving base station 1010 receives the S_Cell addition response message from the mobile base station 1015 and stops forward operation of the DRB whose position is to be reset (step 1055). That is, forward data transmission for the DRB is stopped. However, backward data processing of the DRB continues.

The serving base station 1010 generates an RRC control message indicating the addition of the serving cell and transmits it to the UE 1005 (step 1060). The control message further includes the following information in addition to the information defined in Table 4.

DRB configuration information: information delivered by the mobile base station in step 1050

List of DRBs to be relocated: information delivered by the mobile base station in step 1050

Information related to the scheduling information processing: information transmitted by the mobile base station in step 1050

Reverse transmission rule information: Different reverse transmission rules may be applied depending on whether the serving cell configured in the terminal is a cell of a primary set or a cell of a non-primary set. The uplink transmission rule information is information indicating which uplink transmission rule should be applied in performing uplink transmission in the serving cell in which the UE is configured.

The information is described in ASN. Coded in one coding scheme and delivered to the UE 1005.

Upon receiving the control message, the UE 1005 acquires forward synchronization with respect to the newly set S_Cell (step 1065). Thereafter, when the UE 1005 is ready to perform a random access procedure for the S_Cell, it generates a serving cell additional response control message and transmits it to the serving base station 1010 (step 1075).

In more detail, when the serving cell addition response control message is generated, the UE 1005 transmits a D-SR in the P_Cell or initiates a random access procedure in the P_Cell to transmit the serving cell addition response control message. Request allocation. When the reverse resource is allocated from the cell belonging to the primary set, the UE 1005 transmits a serving cell additional response control message to the serving base station 1010 using the allocated resource.

When the UE 1005 receives the HARQ ACK for the serving cell addition response control message or the RLC ACK, the UE 1005 initiates a random access procedure in a predetermined serving cell of the non-primary set (step 1080). The UE 1005 determines a non-primary set serving cell to initiate a random access procedure by the following method.

[Method of Determining Non-primary Set Serving Cell to Initiate Random Access Procedure]

If there is only one serving cell in which random access related information is set among the serving cells of the non-primary set, the serving cell performs random access.

If there is at least one serving cell in which random access related information is configured among serving cells of the non-primary set, and PUCCH S_Cell is included among them, the PUCCH S_Cell performs random access.

If there is at least one serving cell in which random access related information is set among the serving cells of the non-primary set, and the PUCCH S_Cell is not included among them, the serving cell information is stored first among the serving cells in which the random access related information is stored. Random access in the serving serving cell

If there is at least one serving cell in which random access related information is configured among the serving cells of the non-primary set, and one of them does not include PUCCH S_Cell, the base station performs random access in the serving cell explicitly indicated by the base station.

The random access procedure is a process in which the UE 1005 transmits a preamble in a subframe with a predetermined frequency resource of a serving cell, receives a response message, and performs reverse transmission according to control information of the response message. do. Detailed description will be described later.

As described above, when the random access process is completed, the mobile base station 1015 determines that the UE 1005 can transmit and receive data in the S_Cell of the non-primary set and starts scheduling for the UE 1050.

Therefore, there may occur a case in which backward transmission must be simultaneously performed in the serving cell of the primary set and the serving cell of the non-primary set. In this case, the UE 1005 applies backward transmission rule 1 if the simultaneous transmission is for reverse transmission of the same set, and applies backward transmission rule 2 if the simultaneous transmission is for reverse transmission of different sets (step 1085). . The reverse transmission rule 1 and the reverse transmission rule 2 will be described later.

The serving base station 1010 transmits a serving cell additional control message to the UE 1005 and then performs a DRB relocation procedure with the mobile base station 1015 and the S-GW 1020 (step 1070). The procedure includes transferring data of the DRB to be processed by the mobile base station 1015 from the serving base station 1010 to the mobile base station 1015, and the EPS set between the S-GW 1020 and the serving base station 1010. Releasing EPS bearers corresponding to the relocated DRB among the bearers, and resetting the EPS bearers between the S-GW 1020 and the mobile base station 1015.

In order to initiate data transmission / reception as soon as possible at the mobile base station 1015, the UE 1005 may first initiate a random access procedure for the mobile base station 1015 before sending a serving cell addition response message. have. That is, the UE 1005 starts a random access procedure as soon as it is ready to start random access in S_Cell after receiving the serving cell addition control message. The serving cell addition response message may be performed after the random access procedure is completed or in parallel with the random access procedure. At this time, the UE 1005 transmits the serving cell addition response message only when uplink transmission resources for the serving cell belonging to the primary set are available so that the serving cell addition response message is transmitted to the serving base station 1010.

Hereinafter, a reverse transmission rule according to an embodiment of the present invention will be defined.

The newly defined uplink transmission rule in the present invention is performed when a UE that cannot perform simultaneous backward transmission in two or more serving cells is required to perform simultaneous backward transmission in two or more serving cells. This rule selects reverse transmission.

First, the backward transmission rule 1 is a rule that applies when the serving cells requiring simultaneous transmission belong to the same set (that is, controlled by the same base station and the same scheduler).

For example, the UE should perform backward transmission in subframe x` of serving cell x and backward transmission in subframe y` of serving cell y, and both serving cell x and serving cell y belong to the primary set or all of them. If x 'and y' are partially overlapped on the time axis and belong to the non-primary set, the terminal applies the reverse transmission rule 1.

Since the reverse transmission is controlled by the same base station, the base station may be aware that simultaneous transmission is required for a terminal that is not capable of simultaneous transmission, or the base station may not be aware that simultaneous transmission is required due to an unexpected error. Can be.

In the first case, for example, the PUSCH transmission and the HARQ feedback transmission should be performed at the same time. If the base station never causes such a situation, serious constraints are placed on the forward scheduling or the reverse scheduling. Allow it to occur. It is desirable to have the terminal and the base station transmit and receive the signal in the same manner only when it occurs.

In the second case, for example, HARQ feedback transmission and SR transmission should be performed at the same time. Since the base station can not accurately predict when the terminal will transmit the SR, this case can not be completely excluded.

In this case, it is desirable to transmit a signal having a more important property among the two signals.

In the uplink transmission rule 1, when the uplink transmissions overlap, the terminal selects the uplink transmission based on the following Table 6 in consideration of the properties of each uplink transmission.

Reverse transmission 1 Reverse transmission 2 Selected reverse transmission Remarks One CQI CQI N / A Both signals occur only in P_Cell or PUCCH S_Cell. Invalid case. 2 CQI SRS CQI CQI related to forward signal quality is more important than SRS related to reverse signal quality 3 CQI HARQ AN N / A Both signals occur only in P_Cell or PUCCH S_Cell 4 CQI PUSCH PUSCH + CQI A predetermined portion of the PUSCH transmission resources of the S_Cell is used for CQI transmission. Therefore, CQI transmission is not performed in P_Cell or PUCCH S_Cell, whereas PUSCH transmission of S_Cell is rate matched for CQI transmission. 5 CQI SR N / A Both signals occur only in P_Cell or PUCCH S_Cell 6 SRS CQI CQI same as case 2 7 SRS SRS SRS Send SRS with long period first. Or SRS of the TAG with a TA timer expiration closer. 8 SRS HARQ AN HARQ AN HARQ AN signal is important, so transmit HARQ AN 9 SRS PUSCH SRS In general, control signals are more important than user data. 10 SRS SR SR SR signals that signal data generation are more important than SRS related to reverse signal quality 11 HARQ AN CQI N / A same as case 3 12 HARQ AN SRS HARQ AN same as case 8 13 HARQ AN HARQ AN N / A Both signals occur only in P_Cell or PUCCH S_Cell 14 HARQ AN PUSCH PUSCH + HARQ AN Some of the PUSCH transmission resources of S_Cell are used for HARQ AN transmission. Therefore, HARQ AN transmission is not performed in P_Cell or PUCCH S_Cell, whereas PUSCH transmission of S_Cell is rate matched for HARQ AN transmission. 15 HARQ AN SR N / A Both signals occur only in P_Cell or PUCCH S_Cell 16 PUSCH CQI PUSCH + CQI same as case 4 17 PUSCH SRS SRS same as case 9 18 PUSCH HARQ AN PUSCH + HARQ AN same as case 14 19 PUSCH PUSCH PUSCH We select PUSCH which stored data of high priority RB 20 PUSCH SR SR or PUSCH If the BSR that triggered the SR can be stored in the PUSCH, the PUSCH is selected. If not, select SR. 21 SR CQI NA same as case 5 22 SR SRS SR same as case 10 23 SR HARQ AN NA same as case 15 24 SR PUSCH SR or PUSCH same as case 20 25 SR SR NA Invalid case

Next, the uplink transmission rule 2 is a rule applied when the serving cells requiring simultaneous transmission do not belong to the same set (that is, controlled by different base stations and different schedulers).

For example, the UE should perform backward transmission in subframe x` of serving cell x and backward transmission in subframe y` of serving cell y, and serving cell x belongs to the primary set and serving cell y is non- If it belongs to the primary set or vice versa and x` and y` overlap at least partially on the time axis, the terminal applies backward transmission rule 2. Since the reverse transmission is controlled by different base stations, the base station does not recognize that simultaneous transmission is required for the terminal that cannot transmit simultaneously. Therefore, it is necessary to select backward transmission with more important attributes.

Unlike simultaneous transmission of the same set, in case of simultaneous transmission of different sets, the importance is determined not by the type of reverse signal but by which set the reverse signal is transmitted. As described above, control plane data is mainly transmitted and received in the primary set, and user plane data is mainly transmitted and received in the non-primary set. Therefore, the backward transmission of the primary set is generally more important than the backward transmission of the non-primary set.

In the uplink transmission rule 2, when the uplink transmission overlaps, the UE selects the uplink transmission based on <Table 7> in consideration of which set each uplink transmission is.

Primary set Non-primary set Selected reverse transmission Remarks One CQI CQI Non-primary three transfers In the primary set, control plane data is transmitted and received. Considering that the amount of control plane data is extremely small compared to the amount of user plane data, primary set CQI transmission for the purpose of improving the forward scheduling efficiency of the primary set is very low. 2 CQI SRS 3 CQI HARQ AN 4 CQI PUSCH 5 CQI SR 6 SRS CQI Primary set transfer SRS transmission of the primary set may be used for the purpose of maintaining backward transmission timing in the primary set. Considering that it is necessary to perform backward transmission in the primary set quickly, SRS transmission of the primary set is more important than any backward transmission of the non-primary set. 7 SRS SRS 8 SRS HARQ AN 9 SRS PUSCH 10 SRS SR 11 HARQ AN CQI Primary set transfer Since the HARQ AN of the primary set is an HARQ AN for control plane data, it is more important than any backward transmission of the non-primary set. 12 HARQ AN SRS 13 HARQ AN HARQ AN 14 HARQ AN PUSCH 15 HARQ AN SR 16 PUSCH CQI Primary set transfer The PUSCH transmission of the primary set is for the control plane data transmission and therefore is more important than any backward transmission of the non-primary set. 17 PUSCH SRS 18 PUSCH HARQ AN 19 PUSCH PUSCH 20 PUSCH SR 21 SR CQI Primary set transfer The SR transmission of the primary set is for control plane data transmission and is therefore more important than any backward transmission of the non-primary set. 22 SR SRS 23 SR HARQ AN 24 SR PUSCH 25 SR SR

Reverse transmission rule 2 defined in Table 7 may be summarized as follows.

When the reverse transmission of the primary set and the reverse transmission of the non-primary set overlap on the time axis, if the reverse transmission of the primary set is a CQI transmission, the reverse transmission of the non-primary set is performed, and the reverse transmission of the primary set is performed. If this is not the CQI transmission (or if a reverse transmission other than the CQI transmission is included), the reverse transmission of the primary set is performed.

In the primary set, if only the control plane data is processed, it is desirable to set a very long CQI transmission or SRS transmission period of the primary set. Therefore, the source base station may reset the CQI transmission resource / period and the SRS transmission resource / period of the primary set (or P_Cell) to a minimum value in step 1060.

If the CQI transmission is not frequent in the primary set, the frequency at which the CQI transmission of the primary set overlaps with the backward transmission of the non-primary set is also reduced. Accordingly, in order to simplify UE operation, the uplink transmission rule 2 may be changed as follows so that the uplink transmission of the primary set is selected even for the CQI transmission.

When the reverse transmission of the primary set and the backward transmission of the non-primary set overlap on the time axis, the reverse transmission of the primary set is performed and the backward transmission of the non-primary set is not performed.

In general, since only P_Cell is likely to be set in the primary set, the backward transmission rule 2 can be changed as follows.

When the transmission of the P_Cell and the backward transmission of the S_Cell overlap on the time axis, when the S_Cell is not the serving cell of the primary set, the backward transmission of the P_Cell is performed and the backward transmission of the S_Cell is not performed.

Or it can be further simplified as shown below.

If the transmission of the P_Cell and the backward transmission of the S_Cell overlap on the time axis, the backward transmission of the P_Cell is performed and the backward transmission of the S_Cell is not performed.

11 illustrates an example of a control flow performed by a user terminal to transmit a signal using a plurality of carriers in a mobile communication system according to an exemplary embodiment of the present invention. That is, FIG. 11 shows a terminal operation for selecting reverse transmission when simultaneous reverse transmission is required.

Referring to FIG. 11, the UE monitors whether a situation in which simultaneous requests for backward transmission from a plurality of serving cells should be performed occurs (step 1105). The UE recognizes that a situation in which reverse transmission for a plurality of serving cells is required at the same time occurs when all of the conditions defined below are met.

The UE checks whether at least one cell of the plurality of serving cells requiring backward transmission belongs to the other set (step 1110). For example, the situation in which backward transmission for the serving cell x and the serving cell y must be simultaneously performed is performed by setting information of one serving cell, either serving cell x or serving cell y, as 'serving cell of a base station different from the serving base station'. Or 'information indicating a non-primary set' or 'information for processing a predetermined radio bearer data exclusively in a corresponding serving cell or serving cell group'. Judgment can be made based on the satisfaction of a condition not included. If the condition is satisfied, the UE selects reverse transmission to be performed by applying reverse transmission rule 2 (step 1115). If the condition is not satisfied, the UE selects reverse transmission to be performed by applying reverse transmission rule 1 (step 1120).

12 illustrates another example of a control flow performed by a user terminal to transmit a signal using a plurality of carriers in a mobile communication system according to an exemplary embodiment of the present invention. That is, FIG. 12 illustrates the operation of the UE when the necessity of simultaneously transmitting the PUSCH and the CSI in one or more serving cells occurs.

Referring to FIG. 12, a UE needs to simultaneously transmit a PUSCH and CSI in at least one or more serving cells (step 1205). For example, when CSI transmission is performed in subframe n of P_Cell and PUSCH transmission is performed in subframe m of any serving cell, a case where subframe n and subframe m partially overlap on the time axis may occur. .

The UE checks whether the serving cell on which the CSI transmission is made and the serving cell on which the PUSCH transmission is made belong to different sets (step 1210). For example, CSI is transmitted in the serving cell of the primary set, PUSCH is transmitted in the serving cell of the non-primary set, CSI is transmitted in the serving cell of the non-primary set, or PUSCH is transmitted in the serving cell of the primary set. Check if it is.

If the simultaneous transmission of different sets proceeds to step 1215, and if the simultaneous transmission of the same set proceeds to step 1220.

When the UE proceeds to step 1215, the UE gives priority to the transmission of the primary set and gives up the transmission of the non-primary set. For example, if CSI is transmitted in the primary set, the PUSCH transmission of the non-primary set is abandoned. Or, if the PUSCH is transmitted in the primary set, abandon the CSI transmission of the non-primary set. Alternatively, considering that the importance of the CSI transmission of the primary set is lower than the importance of the PUSCH transmission of the non-primary set, the CSI transmission may be abandoned and the PUSCH transmission of the non-primary set may be performed.

If the CSI is transmitted in the non-primary set and the PUSCH is transmitted in the primary set, the UE may give priority to the PUSCH transmission of the primary set and give up the CSI transmission and perform the PUSCH transmission.

As described above, the PUSCH transmission of the primary set is of high importance, such as the RRC control message transmission.

When backward transmission of two serving cells overlaps on the time axis, the overlapping interval is limited to one subframe if the two cells belong to the same TAG. That is, the subframe N of the serving cell X occupies the same time period as the subframe M of the serving cell Y (reference numeral 1305 of FIG. 13).

When uplink transmissions of two cells belonging to different TAGs overlap, overlapping sections are formed over two subframes. For example, the subframe N of the serving cell X occupies the same time period as the subframe M of the serving cell Y and a part of the subframe M + 1 (reference numeral 1310 of FIG. 13). Alternatively, the same time period may be occupied by part of the subframe M-1 and part of the subframe M. FIG.

For convenience of explanation below, when subframe N of any serving cell X and subframes M and M + 1 of another serving cell Y overlap, or when M-1 and M overlap, subframe M is M It defines and overlaps the subframe N in more time intervals than -1 or M + 1.

When two serving cells belong to the same TAG, it is clear whether backward transmission of any subframe of one serving cell should be compared with backward transmission of which subframe of another serving cell. However, if two serving cells belong to different TAGs, it is difficult to accurately determine a comparison target because any subframe of one serving cell overlaps two subframes of the other serving cell.

In the present invention, for the serving cells belonging to different TAGs, reverse transmission rule 1 or reverse transmission rule 2 is applied to subframes most overlapping with each other among a plurality of overlapping subframes.

Taking backward transmission rule 1 as an example, when the UE performs backward transmission in serving cell X and serving cell Y, CQI in subframe N, HARQ AN in subframe N + 1, PUSCH in subframe M, and sub In frame M + 1, SRS is transmitted. In this case, the UE compares backward transmission of subframe N of serving cell X and subframe M of serving cell Y, compares backward transmission of subframe N + 1 of serving cell X and subframe M + 1 of serving cell Y. Determine which serving cell to perform backward transmission.

For example, if serving cell X and serving cell Y belong to the same set, transmission rule 1 is applied to omit CQI transmission in subframe N and transmit PUSCH and CQI in subframe M together. HARQ AN is transmitted in subframe N + 1, and SRS transmission is omitted in subframe M + 1.

Meanwhile, if the serving cell X belongs to the primary set and the serving cell Y belongs to the non-primary set, the UE transmits the CQI in the serving cell N and omits the PUSCH transmission in the serving cell M. The AN is transmitted in the serving cell N + 1 and the SRS transmission is omitted in the serving cell M.

If it is decided to alternately transmit in adjacent subframes of two serving cells, if CQI is transmitted in subframe N and PUSCH is transmitted in subframe M + 1, in a region where subframe N and subframe M + 1 overlap Simultaneous transmissions may have to be performed.

At this time, the UE performs simultaneous transmission when the length of time period where simultaneous transmission overlaps is smaller than a predetermined reference value. If the UE is larger than the reference value, the UE transmits backward transmission rule 1 or backward transmission rule 1 to subframe N and subframe M + 1. In this case, backward transmission is performed only in one of two subframes.

The UE performs CSI transmission using a portion of the PUSCH transmission resources of S_Cell (step 1220). In this case, as described above, the UE operates differently according to the overlapping degree of the subframe scheduled for CSI transmission and the subframe scheduled for PUSCH transmission.

When CSI transmission is scheduled in subframe X` of serving cell X, and PUSCH transmission is scheduled in subframe Y` of serving cell Y, if UE` and Y` occupy the same time period, the UE Abandoning CSI transmission in serving cell X and transmitting PUSCH and CSI together in serving cell Y (step 1405 of FIG. 14). At this time, some of the PUSCH transmission resources are used for CSI transmission, and rate matching is applied to the PUSCH transmission.

If a part of X` overlaps a part of Y`, and if the length of the overlapping time interval is more than a predetermined reference (for example, more than half of the subframe length), the UE gives up CSI transmission in serving cell X, and the serving In cell Y, PUSCH and CSI are transmitted together (reference numeral 1410 of FIG. 14).

Otherwise, if a part of X` overlaps a part of Y`, and if the length of the overlapping time period is less than a predetermined reference (for example, less than half of the subframe length), the UE performs CSI transmission in serving cell X and the serving cell In Y, PUSCH transmission is performed. At this time, the PUSCH transmission is not performed in the section overlapping the CSI transmission section. That is, transmission is performed only in a part of subframe Y '(reference numeral 1415 of FIG. 14).

Or if X` and Y` only partially overlap and Y` precedes X` (that is, if the start of the subframe scheduled for PUSCH transmission precedes the start of the subframe scheduled for CSI transmission), the UE transmits CSI at Y`. The PUSCH is transmitted only in a time period not overlapping with the time period (or only in a time period not overlapping with X ′) and the CSI is transmitted in all time periods in X ′. If X` and Y` only partially overlap and X` precedes Y` (that is, if the start of a subframe scheduled for CSI transmission precedes the start of a subframe scheduled for PUSCH transmission), then the UE will span Y ' CSI and PUSCH are transmitted together, and C` is not transmitted at X`.

15 shows a control flow for performing random access to a newly added serving cell in a user terminal according to an embodiment of the present invention. That is, FIG. 15 illustrates an operation of a terminal performing random access on a newly added serving cell.

Referring to FIG. 15, the UE receives an RRC Connection Reconfiguration message for adding a new serving cell (step 1505). The RRC connection reconfiguration message is a control message used for various purposes such as adding a new serving cell to a UE, removing or modifying an existing serving cell, modifying an existing radio bearer configuration, and handover command. If the control message contains new serving cell configuration information, for example, serving cell configuration information having a serving cell identifier different from that of the existing serving cell, the UE has received a control message for adding a new serving cell.

The UE checks whether random access related information is stored in the received control message or the configuration information of the newly set serving cell (step 1510).

The random access related information is as defined below.

Information on subframes and frequency resources that can transmit the random access preamble

Power Ramp-Up Information: Information for controlling the power ramp-up operation that raises the random access preamble transmission output in steps, for example ramp-up step size, etc.

Maximum number of preamble transmissions

Information on receiving random access response message: information on the time interval for receiving the response message after the preamble is transmitted

If the information is not stored, the UE proceeds to step 1515 and does not initiate a random access procedure in the newly configured serving cell. Otherwise, if the information is stored, the UE proceeds to step 1520.

In step 1520, the UE checks whether a serving cell associated with the random access related information is a serving cell of a primary set or a non-primary set. That is, it is checked whether the serving cell is a serving cell under the control of the same base station as the base station controlling the P_Cell or a serving cell under the control of another base station. Or, it is checked whether control information indicating that the serving cell is a non-primary set serving cell is included in the control message. For reference, in the present invention, the RRC control message transmitted / received between the UE and the base station is ASN. Encoded as 1. The UE proceeds to step 1525 if the newly added serving cell is the serving cell of the primary set, and proceeds to step 1530 if the serving cell of the non-primary set.

The UE stores the random access related information received in step 1525 and waits until a control information (PDCCH order) indicating that random access is initiated for the serving cell is received. When the control information is received, random serving procedure 1 is initiated in the serving cell.

The PDCCH order is physical layer control information of a predetermined format and instructs the UE to start a random access procedure in a predetermined serving cell. More information can be found in TS 36.211, 36.212, 36.213, 36.321, 36.313 and the like.

[Random Access Procedure 1]

The UE transmits the random access preamble in any serving cell, monitors the control channel (PDCCH) of the P_Cell, receives a random access response message, and transmits the random access preamble by applying a backward grant stored in the random access response message. Perform reverse transmission in the serving cell.

In order to receive the random access response message in the random access procedure 1 described above, the UE monitors the control channel of the P_Cell as follows.

The random access procedure 1 is applied to the case of performing random access in the primary set. That is, both the serving cell and the P_Cell to which the UE transmits the random access preamble are controlled by the same base station. Since receiving a random access response message in one cell rather than receiving it in several cells is preferable in terms of complexity of the UE, the random access procedure 1 monitors the control channel of the P_Cell in order to receive the random access response message.

In step 1525, the UE does not immediately start a random access procedure and waits until receiving a PDCCH order.

The UE proceeding to step 1525 means that the procedure is related to the S_Cell of the primary set. The reason for performing random access in the S_Cell of the primary set is to establish a backward transmission timing of the TAG to which the S_Cell belongs. In this case, the base station recognizes that the UE should perform random access in the S_Cell. Therefore, since the base station that can determine the appropriate random access start time is the base station, it is preferable to start the random access at the time point indicated by the base station.

In step 1530, the UE checks whether condition X is satisfied in order to determine whether to perform random access in the newly configured serving cell immediately.

For example, the condition X may be a non-primary set to which a non-primary set to which a newly set serving cell belongs belongs to a newly set set that has not been previously set, or a newly added serving cell (or a TAG of a newly added serving cell) to an arbitrary non-primary set. Belonging to the non-primary set (or the TAG) and no random access has been successfully performed yet or a newly added serving cell (or TAG of a newly added serving cell) is added to any non-primary set. Random access has not yet been initiated in the non-primary set (or the TAG) or a newly added serving cell belongs to a random non-primary set, and the PUCCH S_Cell of the non-primary set belongs. The TA timer of the TAG has never been run or a newly added serving cell (or a newly added serving cell's TAG) belongs to an arbitrary non-primary set. Said, is in the TAG contains a PUCCH S_Cell, corresponds to the case of the TAG TA timer is not in the drive (or not yet been driven).

If the condition X is satisfied, it means that the reverse timing of the non-primary set to which the newly set serving cell belongs is not yet established, and that the UE should perform an operation required to establish the reverse timing of the non-primary set. Means that.

The UE proceeds to step 1540 when the condition X is satisfied, and proceeds to step 1535 when the UE does not satisfy the condition X.

The UE waits until condition Y is satisfied in step 1535, and starts random access when condition Y is satisfied. The UE applies random access procedure 2 when random access is initiated.

For example, condition Y indicates that a new data is generated in a PDCCH order reception or non-primary set radio bearer for random access initiation of a corresponding serving cell, and the priority of the data is stored in the non-primary set radio bearer. The path loss change of a non-primary set serving cell that is higher than the priority of data or is currently active exceeds a predetermined criterion or meets a predetermined condition (for example, the path loss change of a non-primary set serving cell This is the case when the PHR is larger than the change in the path loss at the time when the PHR was previously reported.

[Random Access Procedure 2]

The UE transmits the random access preamble in any serving cell, monitors the control channel (PDCCH) of the cell (or PUCCH S_Cell) that transmitted the random access preamble, receives a random access response message, and is stored in the random access response message. The reverse grant is applied to perform reverse transmission in the serving cell in which the random access response message is received.

The reason for monitoring the control channel of the cell that transmitted the random access preamble in order to receive the random access response message in the aforementioned random access procedure 2 is as follows.

The random access procedure 2 is applied to the case of performing random access in the non-primary set. That is, the serving cell to which the UE transmits the random access preamble and the P_Cell are controlled by different base stations. In order to transmit and receive a random access response message at the P_Cell, a control message needs to be transmitted and received between base stations, which may cause a significant delay. Therefore, even if the complexity of the UE is slightly increased, receiving a random access response message in the non-primary set is more efficient in terms of overall performance.

In step 1540, if the condition Z is satisfied, the UE starts a random access procedure and applies random access procedure 2. Here condition Z is for the UE to initiate random access as early as possible in the serving cell.

For example, the condition Z corresponds to acquiring a forward synchronization with a corresponding serving cell to recognize a reverse preamble transmission time interval, or to measure a path loss of the serving cell for a predetermined period and to maintain a reliable path loss measurement value.

16 illustrates an example of a control flow performed by a user terminal that receives a control message for setting a serving cell according to an embodiment of the present invention. In FIG. 16, an operation of a UE that receives a control message for configuring a serving cell is illustrated. In particular, the UE discloses an operation according to a method of rapidly delivering scheduling related information in setting up a non-primary set serving cell.

Referring to FIG. 16, the UE receives an RRC connection reconfiguration message in step 1605. The RRC connection reconfiguration message is a control message used for various purposes such as adding a new serving cell to a UE, removing or modifying an existing serving cell, modifying an existing radio bearer configuration, and handover command.

In step 1610, the UE determines whether the received control message is for adding a new serving cell. If the control message contains new serving cell information, for example, serving cell configuration information having a serving cell identifier different from that of the existing serving cell, the UE has received a control message for adding a new serving cell. If a new serving cell is added, the UE proceeds to step 1620. However, if a new serving cell is not added, the UE proceeds to step 1615 and performs a reset operation according to the configuration information stored in the RRC connection reset message.

In step 1620, the UE checks whether the newly set serving cell belongs to the primary set or the non-primary set. That is, it is checked whether the newly set serving cell is a serving cell controlled by the same base station as the base station controlling P_Cell or a serving cell controlled by another base station. Or, it is checked whether control information indicating that the serving cell is a non-primary set serving cell is included in the control message. For reference, in the present invention, the RRC control message transmitted / received between the UE and the base station is ASN. Coded as 1. If the newly added serving cell is the serving cell of the primary set, the UE proceeds to step 1625, and if the serving cell of the non-primary set, the UE proceeds to step 1630.

The UE adds a new serving cell according to the serving cell configuration information received in step 1625 and terminates the process. Adding a new serving cell means an operation such as resetting a radio front end to receive the serving cell.

In step 1630, the UE checks whether condition W is satisfied. If the condition W is not satisfied, the UE proceeds to step 1625. However, if condition W is satisfied, the UE proceeds to step 1635. The condition W is for checking whether the base station controlling the newly set serving cell has received the scheduling information of the UE. If not received (ie, if condition W is satisfied), the UE proceeds to step 1635 to initiate a procedure for quickly sending scheduling information.

An example of the condition W may be defined as follows.

 [Condition W]

The non-primary set to which the newly set serving cell belongs is a newly set set or a newly added serving cell (or a TAG of a newly added serving cell) that has never been set before belongs to an arbitrary non-primary set. No scheduling information has been transmitted in the primary set (or the TAG) or a newly added serving cell (or TAG of a newly added serving cell) belongs to an arbitrary non-primary set, and the non-primary set The random access has not yet been initiated in the TAG (or the TAG) or the newly added serving cell is a PUCCH S_Cell initially configured in an arbitrary non-primary set.

Satisfying the above condition W may perform reverse scheduling for the UE in the non-primary set sooner or later. However, the base station managing the non-primary set means that the UE has not yet received the buffer status report or the power headroom report.

Therefore, the UE triggers the buffer status report and the power headroom report to smoothly schedule in the non-primary set. In this case, the buffer status report and the power headroom report are different from the normal buffer status report and the power headroom report. In the present invention, the buffer status report and the power headroom report are referred to as BSR_NP (Buffer Status Report_NonPrimary) and PHR_NP (Power Headroom Report_NonPrimary).

The UE triggers BSR_NP and PHR_NP in step 1635. At this time, BSR_NP is triggered immediately, and PHR_NP is triggered after a predetermined period has elapsed (or a predetermined condition is satisfied).

The predetermined period is for 1) the time required for the terminal to obtain a reliable path loss measurement value for the newly set serving cell, and 2) to prevent the PHR_NP from being transmitted in the random access procedure.

The BSR_NP has a difference or common point with the conventional BSR as shown in Table 8 below.

Common BSR BSR_NP format Short BSR consists of a 2-bit LCG id and a 6-bit buffer status value.
Long BSR is concatenated with four 6-bit buffer status values, which in turn represent the buffer status for LCG 0, 1, 2, and 3. Same as common BSR Regular BSR Trigger Condition Determine whether or not the regular BSR trigger in consideration of all transmittable data stored in the terminal. More specifically, it is triggered when a new higher priority data occurs than the currently stored data. Among the transmittable data stored in the terminal, it is determined whether the regular BSR trigger is performed only on data of the non-primary set logical channel. More specifically, non-primary data is transmitted from a non-primary set logical channel, and the logical channel belongs to at least one logical channel group, and the priority of the logical channel is currently stored. Triggers regular BSR if higher than the headset logical channel data. Periodic BSR Trigger Condition Triggered when the timer expires. The timer is restarted every time the BSR is sent. Triggered when the timer expires. The timer is restarted each time the BSR is sent over a non-primary set. BSR Content All logical channels set in the terminal are targeted. More specifically, the buffer state of the logical channel, which is configured in the terminal and belongs to the LCG among the logical channels and stores data to be transmitted, is stored for each LCG. Target non-primary three logical channels. More specifically, the buffer state of the logical channel belonging to the LCG among the non-primary set logical channels configured in the terminal and the data to be transmitted are stored for each LCG. For example, logical channel 1 and logical channel 2 are configured in the terminal, logical channels 1 and 2 both belong to LCG 1, logical channel 2 is a non-primary set logical channel, and both logical channels store data to be transmitted. have. In a typical BSR, the sum of data of logical channel 1 and logical channel 2 is reported for LCG 1, but only data of logical channel 2 is reported for LCG 1 in BSR_NP.

The non-primary set logical channel refers to a logical channel through which data is transmitted and received only through a non-primary set serving cell. The base station sets the serving cell of the non-primary set to the terminal, and instructs the terminal which logical channel is the non-primary set logical channel. In the future, the UE multiplexes data generated in the non-primary set logical channel into a MAC PDU transmitted in the non-primary set.

PHR_NP has the following differences or commonalities with conventional PHRs.

Common PHR PHR_NP format Power headroom information or power headroom and maximum transmission output information per serving cell Same as common PHR Regular PHR Trigger Condition When the terminal is allocated a transmission resource for reverse transmission, the path loss of the serving cell that satisfies all of the following conditions is changed by more than a predetermined reference value.
1) Serving cell active
2) Serving cell set as path loss reference cell

Setting any cell A as a path loss reference cell for another arbitrary cell B means referring to cell A's path loss in setting up cell B's reverse transmission output. The base station may establish a path loss relationship using a predetermined control message. The path loss of a non-primary set serving cell that satisfies the following condition is changed by a predetermined reference value or more when the terminal is allocated a transmission resource for reverse transmission.
1) Non-primary set serving cell active
2) Non-primary set serving cell set as path loss reference cell
Periodic PHR Trigger Condition Triggered when the timer expires. The timer is restarted every time the PHR is sent. Triggered when the timer expires. The timer is restarted each time the PHR is sent over a non-primary set. PHR content The power headroom information of the serving cell that satisfies the following conditions among the serving cells configured in the terminal is stored.
1) Serving cell currently active
Contains information about the maximum transmit power of a serving cell that meets all of the following conditions.
1) Serving cell currently active
2) a serving cell having PUSCH transmission in a subframe in which the power head room is transmitted Power headroom information of the serving cell satisfying all of the following conditions among the serving cells configured in the terminal
1) Serving cell currently active
2) Non-primary three serving cells
Contains information about the maximum transmit power of the serving cell that meets all of the following conditions:
1) Serving cell currently active
2) Non-primary three serving cells
3) Serving cell with PUSCH transmission in subframe in which power headroom is transmitted

The non-primary set serving cell in Table 9 refers to a serving cell controlled by a base station other than the base station controlling the P_Cell among the serving cells, and the serving cell in the control message for setting the serving cell. Information indicating whether or not a non-primary set serving cell is signaled.

17 shows another example of a control flow performed by a user terminal receiving a control message for setting a serving cell according to an embodiment of the present invention.

Referring to FIG. 17, the PHR enables the base station to refer to a situation related to the uplink transmission output of the terminal in scheduling uplink transmission in an arbitrary serving cell with respect to the terminal.

The PHR stores the maximum transmit power information applicable to the UE for the serving cell and a difference value (power head room) between the maximum transmit power and the currently used transmit power. Among the various factors affecting the power headroom, in particular the path loss is difficult for the base station to accurately predict its value.

Therefore, the terminal triggers the power headroom when the current path loss is changed by more than a predetermined criterion compared to the path loss applied when the power headroom is most recently reported.

If a pico cell is configured for a terminal operating in a macro cell, the path loss of the pico cell is likely to be significantly lower than the path loss used by the terminal. Therefore, it is desirable to report the power headroom. However, previously defined triggers, e.g. triggers based on change values from previous path loss, are not helpful. This is because, when a new serving cell is added, there is no previous path loss.

The present invention provides a method of triggering a power headroom when a new pico cell is set.

In step 1705, the UE receives an RRC connection reconfiguration message. The RRC connection reconfiguration message is a control message used for various purposes such as adding a new serving cell to a UE, removing or modifying an existing serving cell, modifying an existing radio bearer configuration, and handover command.

If the received control message includes control information for adding a new serving cell, the UE adds a new serving cell and waits until the serving cell is activated.

If the UE receives the control message for activating the serving cell in step 1710, the UE proceeds to step 1715.

In step 1715, the UE determines whether the PHR trigger condition defined below is satisfied in order to determine whether PHR should be triggered for the activated serving cell.

[PHR Trigger Condition]

1) A new serving cell that has never been activated is activated

2) The serving cell is a serving cell in which a reverse direction is set.

3) The serving cell is activated for the first time for any TAG

4) Extended PHR format is set.

Herein, the extended PHR format is a format configured to report power headroom of all activated serving cells, and a general PHR format is a format configured to report only P_Cell power headroom. Since the general PHR format is set, the base station does not consider the power headroom of the cells except P_Cell. Therefore, the PHR trigger is preferably limited to the case where the extended PHR format is set.

The UE proceeds to step 1725 if the PHR trigger condition is satisfied, and proceeds to step 1720 if the PHR trigger condition is not satisfied.

In general, macro cells and pico cells belong to different TAGs. Therefore, when the TAG is initially set as described above, PHR is triggered for the serving cells belonging to the TAG.

The condition may be modified as follows.

[Modified PHR Trigger Condition]

1) Serving cell of newly set TAG.

2) at least one serving cell in which a reverse direction is set in the TAG.

3) The PHR has not been triggered yet (or the PHR has never been transmitted) in the serving cell of the TAG.

4) Extended PHR format is set.

Also, when paying attention to path loss, the PHR trigger condition may be modified as follows.

[Another PHR trigger condition]

1) A new serving cell that has never been activated is activated

2) The serving cell is a serving cell in which a reverse direction is set.

3) The path loss of the serving cell and the path loss difference of another serving cell which is currently activated and is set as a path loss reference cell is greater than or equal to a predetermined reference (for example, a serving cell in which a new serving cell A is activated and is currently active) When there are B, C, and D, and serving cell B acts as a path loss reference cell for serving cell B and serving cell C acts as a path loss reference cell for serving cells C and D, Any one of the difference between the path loss of the serving cell B, the difference between the path loss of the serving cell A and the path loss of the serving cell C exceeds a predetermined criterion)

4) Extended PHR format is set.

The UE performs activation on a cell indicated for activation in step 1720. Specifically, PDCCH monitoring is started for the cell, channel information (CSI) reporting is started for the cell, and SRS transmission of the cell is started.

In step 1725, the UE performs activation on the cell indicated to be activated, and triggers PHR when a predetermined condition is satisfied. The condition may be, for example, a time point at which a path loss measurement value for the activated serving cell is available.

Of the serving cells belonging to the non-primary set, a predetermined serving cell may transition to an activated state without receiving a separate activation command. For the serving cell, the step of receiving a serving cell activation command 1710 may be changed to a step of activating the serving cell. For example, when the UE receives an RRC connection reconfiguration message for adding an arbitrary serving cell, the UE checks whether the newly added serving cell is type 1 or type 2. The type 1 serving cell is a serving cell activated by a separate control message (Activation / Deactivation MAC CE) indicating activation, and the type 2 serving cell is activated by a method other than a separate control message indicating activation. Means. The type 2 serving cell may include, for example, PUCCH S_Cell, and the PUCCH S_Cell is activated at the start of the random access procedure. The type 1 serving cell may include the remaining S_Cell except for the PUCCH S_Cell. The UE waits for a type 1 serving cell to receive an activation command, and upon receiving an activation command for the serving cell, checks whether a reverse direction is set in the serving cell. If the reverse direction is set, PHR is triggered.

For the type 2 serving cell, the UE waits until the activation condition is established, and triggers the PHR when the condition is established. More specifically, when the PUCCH S_Cell is configured, the UE waits until random access is initiated in the PUCCH S_Cell, or waits until a preamble is transmitted, or a random access response message is transmitted in the random access procedure. Wait until received, and trigger PHR when a random access response message is received. Since the random access response message includes a reverse grant, the terminal reports the PHR in the first reverse transmission for the PUCCH S_Cell after receiving the random access response message. In this case, the PHR trigger time may be defined as a time when the first backward transmission is performed so that more important data may be transmitted instead of the PHR in the first backward transmission.

18 illustrates a control flow performed by a user terminal receiving a reverse grant message according to an embodiment of the present invention.

Referring to FIG. 18, the UE receives a reverse grant in step 1805. In this case, the reverse grant is performed by a control message transmitted by the base station through the PDCCH to indicate the reverse transmission to the UE. When the UE receives the backward grant, the UE can know when to use reverse transmission in which serving cell to perform reverse transmission. The UE selects what data to transmit in consideration of which serving cell the reverse grant is for.

The UE checks whether the following conditions are true in step 1810.

<Conditions on how to select data to transfer>

A non-primary set serving cell is configured in the UE;

Non-primary set logical channel set up in UE

If the condition does not hold, the UE proceeds to step 1820, and if the condition holds, the UE proceeds to step 1815.

In step 1820, the UE determines what data is transmitted and how much, in consideration of transmittable data currently stored and BSR, PHR, and the like. At this time, the UE considers a predetermined priority as follows. The data is the highest priority in the order from top to bottom.

Common Control Channel (CCCH) data

BSR (except for BSRs created to fill padding space)

PHR

Data in a logical channel that stores data that can be transmitted.

Data of the logical channel is prioritized according to the logical channel priority given to the logical channel.

The UE selects data to be transmitted so that data having a higher priority is transmitted according to priority.

The CCCH data means a predetermined RRC control message. RRC CONNECTION REESTABLISHMENT REQUEST message that the UE exchanges with the base station for the first control message (RRC CONNECTION REQUEST) or the UE temporarily loses the connection with the base station and then returns again due to poor wireless environment or the like. Can be.

Although the CCCH data is the data of the logical channel, it is not explicitly given priority and is implicitly processed at the highest priority.

In step 1815, the UE checks whether the backward grant is for a serving cell of a primary set or a non-primary set serving cell. The fact that the any backward grant is for any serving cell means that the backward grant indicates the backward transmission of the serving cell.

The UE proceeds to step 1825 if the backward grant relates to the primary set serving cell and proceeds to step 1830 if it relates to the non-primary set serving cell.

In step 1825, the UE determines what data is to be transmitted and how much in consideration of BSR_P, PHR_P, and transmittable data stored in the primary set logical channel. BSR_P is a BSR generated by data of a primary set logical channel, and the concept of BSR_NP described in Table 8 is extended to a primary set logical channel and a primary set serving cell. That is, in the description of BSR_NP in Table 8, the BSR_P is explained by replacing the non-primary set logical channel with the primary set logical channel and the non-primary set serving cell with the primary set serving cell.

PHR_P is a PHR generated for the primary set serving cell, and the concept of PHR_NP described in Table 9 is extended to the primary set serving cell. That is, when the non-primary set serving cell is replaced with the primary set serving cell in the description of PHR_NP of Table 9, PHR_P is explained.

The primary set logical channels are logical channels except for those designated as non-primary set logical channels among logical channels configured in the terminal, and are logical channels transmitted and received only through the serving cell of the primary set. CCCH is always included in the primary set logical channel.

In step 1825, the UE selects data to be transmitted by applying the following priority.

Common Control Channel (CCCH) data

BSR_P (except BSR_P created to fill padding space)

PHR_P

Data of primary set logical channel where data that can be transmitted is stored.

The data of the logical channel is prioritized according to the logical channel priority given to the logical channel.

The UE selects data to be transmitted so that data having a higher priority is transmitted according to priority.

In step 1830, the UE determines what data is transmitted and how much in consideration of BSR_NP, PHR_NP, and transmittable data stored in a non-primary set logical channel. In this case, the following priority applies.

BSR_NP (except BSR_P created to fill padding space)

PHR_NP

Data in a non-primary set logical channel containing transmittable data.

Data of the logical channel is prioritized according to a logical channel priority given to the logical channel.

The terminal selects data to be transmitted so that data having a higher priority is transmitted according to the priority.

Second Embodiment

If the terminal in idle state is informed of what service or transmission rate the terminal can be provided in the current serving cell, it is possible to deliver the information to the user through the screen of the terminal. The user may determine whether to start a data service in a corresponding serving cell using the information.

The transmission speed experienced by an arbitrary terminal is influenced by various factors such as the available bandwidth, the number of MIMO layers, the load state, and the processing capability of the terminal. In the present invention, when the base station considers carrier aggregation through system information, the total bandwidth that can be aggregated, the number of serving cells, the number of MIMO layers that can be provided by the serving cells, and the current load state can be allocated to a new terminal. The ratio of resources is broadcast, and the terminal calculates and displays the expected data rate on the screen in consideration of the above information and its processing capacity.

Figure 21 shows the overall operation of the present invention.

An idle terminal 2205 in which no RRC connection is established selects cell a 2210 controlled by ENB 1 and camps on. Camping on any cell means receiving system information of the cell and monitoring the calling channel. The terminal in the idle state camps on a cell accessible by the terminal while the channel quality is higher than a predetermined standard through cell selection and cell reselection.

The performance of the terminal supports, for example, CAs in a base station for up to two serving cells, and the maximum number of MIMO layers is 4 (2215).

The performance of cell a is, for example, a cell bandwidth of 10 MHz and a maximum number of MIMO layers of two. Base station 1 can carrier-integrate cell a and cell b. Cell b has a cell bandwidth of 20 MHz and a maximum number of MIMO layers of 4 (2217).

Base station 1 broadcasts the following information related to the serving cell itself and a neighboring cell capable of carrier aggregation through a predetermined SIB of cell a (2220).

Whether to support CA and MIMO in base stations = supported

Aggregated BW with CA = 30 MHz

The combined bandwidth of cell a and cell b

Cell information that can be carrier aggregation

Information indicating cell b. EUTRA Absolute Radio Frequency Channel Number (EARFCN), which indicates the center frequency of cell b, or information indicating which cell among inter-frequency neighboring cells of SIB 5 can be carrier-carried (for example, a position stored in SIB 5) An integer representing)

MIMO layer count when applying CA = 6

The sum of the MIMO layer of cell a and the MIMO layer of cell b

MIMO layer count when CA is not applied = 2

MIMO layer of cell a

Load = 0.9 without CA

The load situation in cell a. For example, 90% of all transmission resources are in use.

Load = 0.8 with CA

Summing load situation of cell a and cell b. For example, 80% of transmission resources of cells a and b are in use.

The UE calculates an expected data rate when the RRC connection is established in the corresponding cell in consideration of the information and its performance.

Expected data rate = BW * spectral efficiency * (1-load)

The frequency band combination to which the UE can apply CA is defined in advance, and the UE is defined in the frequency band combination (in this example, the combination of the frequency band of cell a and the cell b is frequency band) announced as applicable to CA in system information. If you support CA, use aggregated BW for the BW.

The UE determines the spectral efficiency in consideration of the number of MIMO layers for each serving cell. The UE may database the spectral efficiency per MIMO layer number, and determine the spectral efficiency from the number of MIMO layers available at a corresponding time. For example, if the number of MIMO layers is n, the average spectral efficiency is xb / s / Hz. If the number of MIMO layers is m, the average spectral efficiency is yb / s / Hz. If n, the spectral efficiency is x.

The terminal displays information such as whether the MIMO / CA is supported and the expected data rate by using a graphical symbol on the screen.

For example, whether or not MIMO / CA is supported may be represented by two arrows (or two or more arrows) if CA is not supported and one CA is supported. The expected data rate can be displayed using a representative value in a predetermined range, for example, 100 between 10 and 100 Mbps, and 500 between 100 and 500. Alternatively, the thickness or color of the arrow may represent the expected data rate.

When the UE reselects a new serving cell, it performs the same procedure to update the information on the screen to an appropriate one. If the terminal does not support CA between base stations, the terminal may determine that the CA is not supported in cell c (2235) and display only one arrow. The CA calculates and displays the expected data rate on the screen when CA is not supported.

Third Embodiment

If the terminal experiences a continuous random access failure, there may be two causes. Congestion has occurred in the current cell, or the downlink of the current cell is good but the uplink is poor. In the second case, for example, the downlink signal reflected on the water surface is received by the terminal.

If the continuous random access failure is due to the first cause, it is likely that the current serving cell is the cell with the best channel quality, and reselecting another cell may adversely affect the system. On the other hand, in case of random access failure by the second cause, the current serving cell is felt as the best cell by abnormal signal path even though the channel quality is not the best cell. More preferred.

Cell congestion can be deduced from several things. For example, if the access class prohibition information (ac-Barring Info) is broadcast as the system information of the current cell, it means that there is some degree of congestion even though the degree is different. Alternatively, if the terminal receives at least one or more back-off indicators when performing the random access, it means that there is congestion on the random access channel. Alternatively, if there is a contention failure while performing random access, it means that there is congestion on the random access channel.

In the present invention, when a random access failure occurs, the terminal receives one or more back-off indicators in the random access process, has experienced contention failure, or broadcasts access class prohibition information (ac-Barring Info) as system information. If so, the random access operation resumes after reselecting a cell having the best downlink channel condition among neighboring selectable cells including the current cell. If a random access failure occurs, if no back-off indicator has been received, no contention failure has occurred, or no access class prohibition information is being broadcast as system information, the downlink channel situation of the remaining cells except the current cell Reselect the best cell and resume random access operation.

23 illustrates the operation of the terminal.

In step 2305, a random access problem occurs in the P_Cell. That is, if a UE transmits a preamble a predetermined number of times in P_Cell but does not receive a valid random access response message, a random access problem occurs. The UE manages the number of preambles transmitted in the current random access process in a variable called PREAMBLE_TRANSMISSION_COUNTER, and receives a parameter called preambleTransMax in the RRC connection establishment process. After the UE transmits the preamble, whenever a valid random access response message is not received, the UE increases the PREAMBLE_TRANSMISSION_COUNTER by 1 and compares the value with one greater than the preamble_Trans_Max. If the PREAMBLE_TRANSMISSION_COUNTER is small, the preamble retransmission process is performed. If the PREAMBLE_TRANSMISSION_COUNTER is equal to 1 greater than the preamble_Trans_Max, it is determined that a random access problem has occurred.

A valid random access response message is a random access response message that satisfies the following conditions.

A random access response message addressed with an identifier (RA-RNTI) mapped to a time / frequency resource from which a terminal transmits a preamble, and containing a preamble identifier (RAPID) mapped to a preamble transmitted by the terminal.

In step 2310, the UE determines whether the random access problem is due to congestion or forward / backward imbalance.

<Failure random access due to congestion 1>

Receive a back-off indicator at least once while performing the random access.

The back-off indicator is information indicating that the base station delays the preamble transmission to the terminal. The back-off indicator is stored in a random access response message and transmitted to a plurality of unspecified terminals.

<Random Access Failed 2 due to Congestion>

The amount of back-off applied during the random access is greater than or equal to the predetermined reference value.

<Failure random access due to congestion 3>

At least one contention failure occurs during the random access

<Failure random access due to congestion 4>

Access class prohibition information is broadcasted as system information while performing the random access.

Access class prohibition information is described in 36.331.

The terminal proceeds to step 2315 if the random access failure condition due to congestion is satisfied, and proceeds to step 2320 if it is not satisfied.

Or, if the random access failure condition due to the forward / reverse imbalance is satisfied, the terminal proceeds to step 2320, and otherwise proceeds to step 2315. Random access failure conditions due to the forward / reverse imbalance may be as follows.

<Failure to random access due to forward / reverse imbalance>

No valid random access response message has been received during this random access.

In step 2315, the UE searches for a new accessible cell by performing a cell selection process. At this time, the UE measures the forward channel reception strength / quality of the current serving cell and neighboring cells, and checks whether the serving cell is an access prohibited cell. If the new cell is selected, the terminal proceeds to step 2325.

In step 2320, the UE searches for a new cell accessible from the remaining cells except the current serving cell. If the new cell is selected, the terminal proceeds to step 2325.

In step 2325, the UE performs a random access process by applying the random access related information of the SIB2 of the cell. The terminal transmits a message called rrc_Connection_Reestablishment_Request through the random access process. The control message includes an identifier (PCI, Physical Cell Id) of a previous serving cell of the terminal, C-RNTI information used in the previous serving cell. If the base station knows the terminal or has information about the terminal, the base station recovers the RRC connection by transmitting a control message (rrc_Connection_Reestablishment) indicating an RRC connection reset.

In a serving cell in which forward / reverse imbalance exists, the RRC connection state transition process of the UE is likely to fail continuously.

27 illustrates a control flow performed by a terminal when an RRC connection process failure due to a forward / reverse imbalance occurs according to an embodiment of the present invention.

Referring to FIG. 27, in step 2805, the UE camps on an arbitrary cell. That is, the terminal acquires system information from an arbitrary cell, monitors a call channel, and so on. Thereafter, when a necessity of establishing an RRC connection occurs at any time (requesting to establish an RRC connection from an upper layer to an RRC layer), the terminal proceeds to step 2810 and generates an RRC connection request message. After transmitting the generated rrc connection request message to the RLC layer device, it drives T300.

In step 2815, the UE initiates and performs a random access procedure in the current cell. In this case, the random access process includes transmitting a preamble, receiving a random access response message, transmitting message 3 by using a reverse transmission resource indicated in the response message, and receiving message 4 as a response message. . Message 3 and Message 4 may each correspond to an RRC connection request message and an RRC connection setup message.

If a valid random access response message is not received even though the preamble is transmitted, the terminal retransmits the random access preamble. Also, even if the message 3 is transmitted but the message 4 is not received, the terminal retransmits the random access preamble.

The terminal checks whether T300 expires before the random access procedure is successfully completed. If T300 expires before the random access process is successfully completed, the process proceeds to step 2825. If T300 has not expired before the random access process is successfully completed, the process returns to step 2815. When the terminal returns to step 2815, the terminal continues the random access process.

In step 2825, the UE resets the MAC to stop the random access process. In step 2830, it is checked whether the 'current serving cell access restriction condition' is satisfied.

[Current serving cell access restriction condition 1]

No valid random access response message was received while the T300 was running.

[Current Serving Cell No Access Condition 2]

T300 has expired continuously in the current serving cell. That is, the RRC connection establishment process fails continuously in the current serving cell.

If the condition is not satisfied, the terminal proceeds to step 2835 and reports to the higher layer that the RRC connection configuration has failed, and waits until the RRC connection configuration is needed again, that is, until the higher layer requests the RRC connection configuration again. .

Proceeding to step 2840 means that an RRC connection establishment failure is most likely due to a forward / reverse imbalance. Accordingly, the terminal determines that access is prohibited to the current cell for a predetermined period of time to select a serving cell other than the current serving cell. The predetermined period is a first period when the terminal is a general terminal and a second period if the terminal is a machine type device (for example, a metering device) with no mobility at all. Which one of the first and second periods the terminal applies is set in advance in the memory, OS, or the like of the terminal.

The UE proceeds to step 2845 to report that the RRC connection setup has failed to the upper layer, and performs a cell reselection process for cells except the current cell. That is, a cell that meets a predetermined criterion is selected as a new serving cell among cells whose channel quality / receive strength is greater than or equal to a predetermined criterion. Wait until the RRC connection is set up again.

Fourth Embodiment

One serving cell is specified by one center frequency, but may belong to several frequency bands. For example, some of the frequency bands belonging to the frequency band x may belong to a newly defined frequency band, in which case one center frequency may belong to several frequency bands. The cell broadcasts frequency band information using system information. If a cell supports multiple frequency bands, the base station broadcasts all the supported frequency bands through the system information. At this time, the frequency band having the highest priority among the frequency bands is broadcast as first information (freqBandIndicator) and the remaining frequency bands are broadcast as second information (multiBandInfoList).

The value of EARFCN, which specifies the center frequency, varies depending on which frequency band is applied. The relationship between frequency bands and EARFCN is described in 36.101. Using EARFCN, a security key (KeNB *) to be used at the target base station is calculated. Therefore, if the target cell is a cell supporting multiple frequency bands, the UE and the base station should calculate KeNB * using the same EARFCN. 23 will be described in more detail.

The terminal 2405 establishes an RRC connection with the cell a 2410 having the center frequency f1 and performs a normal data transmission / reception process. At any point in time, the source base station instructs the terminal to perform measurement on a predetermined measurement target (2420). The measurement object is, for example, cells having a center frequency f2. If there are cells belonging to frequency band x and frequency band y among cells having a center frequency of f2, the terminal selects one of two frequency bands, determines an EARFCN corresponding to the center frequency f2, and notifies the terminal.

In more detail, the source base station notifies the terminal of an EARFCN (hereinafter, referred to as a first EARFCN) corresponding to a frequency band broadcast with the first information as a measurement target. For example, f2 may belong to frequency band x and frequency band y, and when EARFCN is n in frequency band x and EARFCN is m in frequency band y, if n is EARFCN broadcasted as first information, the base station transmits EARFCN to the terminal. Specify n as the measurement target. An identifier (measurement ID) of an integer is assigned to the measurement object.

The terminal measures the frequency specified by the first EARFCN. If it is detected that the channel quality / receive strength of a predetermined cell, for example, cell b, is better than the current serving cell, a measurement result control message is generated and transmitted to the base station (2425). The message includes information on a measurement target, that is, information related to a measurement target ID. The measurement result and the identifier of the cell that triggered the measurement report are stored.

The base station 2410 determines to hand over the terminal to cell b, and determines the EARFCN specifying the center frequency of the cell b. If cell b (ie the target cell) belongs to several frequency bands, i.e. associated with several EARFCNs, then the first EARFCN is selected.

In other words, the EARFCN calculated by the frequency band of the first information is selected. Or select the EARFCN used to indicate the measurement target. The base station inserts various variables such as the EARFCN and the identifier of the target cell into a predetermined key generation function to generate KeNB * (2430), and transmits a handover request control message including the KeNB * to the target base station. The target base station determines whether to accept the handover in consideration of the current load situation or the QoS of the traffic to be handed over.

If the handover is accepted, a handover request accept control message is generated (2440) and transmitted to the source base station (2445). The control message contains EARFCN information of the target cell, and the information is EARFCN calculated by the frequency band of the first information. That is, the target base station stores the EARFCN calculated by the frequency band broadcasted by the first information in the target cell in the control message.

The source base station transmits an RRC connection reconfiguration message supporting the handover to the terminal. The control message contains a first EARFCN indicating the center frequency of the target cell.

In step 2455, the terminal generates a KeNB * by inputting the first EARFCN or the like into a predetermined key generation function. If the random cell performs a random access procedure and the random access succeeds, the RRC connection reconfiguration completion message protected by the new key is generated and transmitted to the target base station.

24 illustrates a signal processing procedure according to another embodiment of the present invention.

Referring to FIG. 24, the terminal 2505 establishes an RRC connection with a cell a 2510 having a center frequency f1 to perform a normal data transmission / reception process. At any point in time, the source base station 2510 instructs the terminal performance report to the terminal (2520), and in response to the terminal generates a terminal performance report control message and transmits to the source base station 2510 (2525). The control message contains information about a band supported by the terminal.

The UE may support only FB x, only FB y, or both FBs. If the UE reports that it supports at least one FB of FB x and FB y, the source base station 2510 may consider handing over the terminal 2505 to cell b. The source base station 2510 sets the measurement to the terminal 2505, and reports (2527) the measurement result containing the information that the terminal 2505 needs to hand over to the cell b, the source base station 2510 ) Determines to hand over the terminal 2505 to cell b (2530).

The source base station 2520 calculates KeNB * as follows (2537).

Select the FB to apply to cell b

EARFCN corresponding to the center frequency of cell b by applying the selected FB

KeNB * generation by inputting information such as EARFCN and target cell identifier into key generation function

In selecting the FB of the target cell supporting one or more FBs, the source base station selects the FB supported by the terminal if there is only one FB supported by the terminal among the FBs of the target cell, and the terminal among the FBs of the target cell If there is more than one supported FB, a predetermined rule is applied to select the FB.

[FB Selection Rule 1]

Select the lowest FB among the FBs supported by both the target cell and the terminal.

For example, if the center frequency of the target cell, or the frequency band belongs to frequency band x and frequency band y and x> y, and the terminal also supports both frequency band x and frequency band y, the base station selects frequency band y. do.

[FB Selection Rule 2]

Select the highest FB among the FBs supported by both the target cell and the terminal.

For example, if the center frequency of the target cell or the frequency band belongs to frequency band x and frequency band y and x> y, and the terminal also supports both frequency band x and frequency band y, the base station selects frequency band x. do.

[FB Selection Rule 3]

Among the FBs supported by both the target cell and the terminal, the terminal selects the FB reported in the front of the performance report control message.

For example, if the center frequency of the target cell, or the frequency band belongs to frequency band x and frequency band y, and x is reported before y in the performance report control message, the base station selects frequency band x.

[FB Selection Rule 4]

Among the FBs supported by both the target cell and the terminal, the terminal selects the FB reported at the end of the performance report control message.

For example, if the center frequency of the target cell, or the frequency band belongs to frequency band x and frequency band y, and x is reported before y in the performance report control message, the base station selects frequency band y.

Alternatively, the source base station may select the EARFCN using the size of the EARFCN. For example, you can choose the larger or smaller of the EARFCN with FB x and the EARFCN with FB y.

The source base station 2510 transmits a handover request control message including the KeNB * to the target base station 2515 (2535). The control message also stores the performance information of the terminal, that is, information on the frequency band supported by the terminal.

The target base station 2515 determines whether to accept the handover in consideration of the current load situation or the QoS of the traffic to be handed over. If the handover is accepted, the target base station 2515 selects the FB by applying the same FB selection rule used by the source base station 2510 (2537). A handover request acceptance control message containing the EARFCN calculated by applying the selected FB is generated (2540) and transmitted to the source base station 2510 (2545).

The source base station 2510 transmits an RRC connection reconfiguration message supporting the handover to the terminal 2505 (2550). The control message stores an EARFCN indicating the center frequency of the target cell, that is, the EARFCN determined by the target base station in step 2540.

In step 2555, the terminal 2505 generates the KeNB * by inputting the EARFCN to a predetermined key generation function. In addition, the random access procedure is performed in the target cell. If the random access succeeds, a protected RRC connection reconfiguration complete message is generated through the new key and transmitted to the target base station 2515.

<Fifth Embodiment>

In another embodiment of the present invention, to reduce power consumption, a terminal using a very long DRX cycle checks the changed SI (System Information) broadcasted by the base station and proposes a method of updating the same. A terminal using the very long DRX cycle belongs to a machine type communication (Machine Type Communication) that transmits and receives data by connecting to a base station very rarely.

In the present embodiment, a terminal to which a very long DRX cycle is applied proposes a method of confirming and updating an SI in advance before a call occasion.

The method may have two options.

The first option is to determine whether the SI information is changed by receiving the SIB1 before the call occasion receives the SIB1 and checking the value_Tag information included in the SI information. If the SI information has changed, update the SI information. Value_Tag included in SIB1 increments the counter value by one when the SI information is changed. The terminal compares the value_Tag value stored in the SIB1 with the latest value_Tag value stored by the terminal, and determines that the SI information has changed if they are not equal to each other.

The second option is that the UE that wakes up before the calling occasion updates the SI information.

Both options can be applied depending on the very long DRX cycle applied. For example, if a very long DRX cycle has a length of less than 3 hours, the first option is preferred. Otherwise, if more than 3 hours, the second option is preferred. In the prior art, the validity for SI information is defined as 3 hours. After 3 hours after the UE acquires the SI information, the terminal regards the acquired SI information as invalid, and newly receives and stores the SI information.

Alternatively, a method of delaying the operation of the terminal may be considered until the terminal knows whether a call has come to it.

When the UE needs to switch to the active state, it performs a cell reselection operation. The terminal can receive a call only when it becomes an acceptable state (agree state), and after receiving the call, performs a call reselection operation. According to a specific condition, the agreement state of the terminal is determined. The terminal operation is delayed until the terminal is in agreement. The delay time may be predetermined or set from the base station and, after an acceptable delay time, may be received by another method.

Alternatively, a method of reducing terminal consumption of the terminal may be used by preventing unnecessary SIB1 and other SIB reception. Attempts to receive SIB1 and other SIBs are a cause of obvious power consumption.

In general, minimizing MIB reception is very limited when using very long DRX cycles. MIB includes only essential information such as SFN (System Frame Number), frequency band, PHICH configuration information. In particular, since the DRX cycle operates based on SFN information, MIB reception is essential. In contrast, unnecessary SIB1 and other SIB reception attempts can be reduced.

There are two options to reduce unnecessary SIB1 reception attempts.

The first option is to add value_Tag to the MIB. In the prior art, value_Tag is included in SIB1. Therefore, in order to confirm whether the SI information is changed, the SIB1 information should be received. However, if the SI information has not changed, the reception of the SIB1 information will be an unnecessary operation. This causes power consumption of the terminal.

The second option is to add a larger value_Tag to the MIB. The current value_Tag has a value from 0 to 31 and is incremented by 1 whenever the SI information is changed once. If the UE uses a very long DRX cycle, SI information may be changed more than 32 times within the period. Thus, a larger value_Tag may be needed.

Sixth Embodiment

When the MBMS service is provided in a cell supporting multiple frequency bands, a method and apparatus for receiving an MBMS service in the cell by the terminal will be described as a sixth embodiment.

25 illustrates a signal processing procedure according to another embodiment of the present invention.

Referring to FIG. 25, the terminal 2605 establishes 2620 an RRC connection with a cell a 2610 and transmits and receives data through the cell.

At any point in time, the terminal 2605 starts receiving the MBMS service over the multicast channel (MCH) or recognizes that the MBMS service to be received will soon be started (2623). The terminal 2605 may determine whether the MBMS service will start soon by using the service start / end time indicated in the user service information (USD). In addition to the above information, the USD also includes information defining a mapping relationship between the MBMS service and the SAI, and is obtained through SMS, MMS, or IMS (IP Multimedia Subsystem).

In step 2625, the terminal 2605 acquires SIB 15 that contains MBMS service related information of neighbor cells. If the terminal 2605 has already obtained SIB 15, step 2625 may be omitted. In SIB 15, information indicating which service area the surrounding frequency belongs to is stored. The information consists of EARFCN and SAI.

For example, if f2 corresponds to SAI n and SAI m, and f3 corresponds to SAI k and SAI h, SIB 15 stores the following information.

EARFCN x (EARFCN of f2), SAI n, SAI m

EARFCN y (EARFCN of f3), SAI k, SAI h

If there is a SAI associated with the service currently being received or the service to be received, the terminal 2605 generates and transmits a control message MBMSInterestIndication containing the EARFCN of the SAI to the base station 2610 (2640).

If there is a frequency belonging to several frequency bands among the frequencies provided with the MBMS service, the base station 2610 transmits the EARFCN individually for each frequency band. For example, f2 belongs to FB w and FB z, and EARFCN is x and x`, respectively. The base station broadcasts the following information to the SIB 15.

EARFCN x (EARFCN of f2), SAI n, SAI m

EARFCN x` (another EARFCN of f2), SAI n, SAI m

EARFCN y (EARFCN of f3), SAI k, SAI h

Upon receiving SIB15, the terminal 2605 identifies the EARFCN to which the MBMS service to be received is provided, that is, the SAI matches. When several EARFCNs correspond to one frequency (2630), if only one EARFCN is understood, the terminal 2605 selects the EARFCN (2635). However, if one or more EARFCNs are understood, that is, if different EARFCNs actually specify the same frequency, the terminal 2605 selects the EARFCN by applying a predetermined rule (2635).

[EARFCN Selection Rule 1]

Determined based on the magnitude and magnitude of the corresponding frequency band identifier. For example, select the lowest EARFCN or highest EARFCN with frequency band identifier.

[EARFCN Selection Rule 2]

Determined based on the big and small of EARFCN. For example, select the lowest EARFCN or the highest EARFCN

The terminal 2605 generates a control message containing the selected EARFCN and transmits the generated control message to the base station 2610. The base station 2610 determines whether to hand over the terminal 2605 with reference to the message in the future. That is, the terminal 2605 recognizes the frequency at which the MBMS service is received and manages the mobility of the terminal 2605 with care not to cause a situation in which the terminal 2605 does not receive the frequency.

26 illustrates a control flow of a terminal according to another embodiment of the present invention.

Referring to FIG. 26, in step 2705, the UE recognizes that an MBMS service or an MBMS session that it intends to receive will start soon.

In step 2710, the UE checks the SAI information for each frequency of SIB15 to determine whether there is a frequency capable of receiving the MBMS session. More specifically, the terminal checks whether the following conditions are satisfied.

Among the frequencies included in SIB 15 of P_Cell, there is an SAI corresponding to the MBMS session that the UE intends to receive. This frequency is called frequency x.

The terminal may simultaneously receive the frequency X and the current serving frequency.

A band of frequency x is included in the supported frequency band combination (supported_Band_Combination) reported by the UE in the UE performance report control message.

If no frequency x exists, the process ends. However, if the frequency x exists, the process proceeds to step 2715 to select the EARFCN for the frequency. In step 2720, the UE generates and transmits a MBMS_Interest_Indication control message containing the EARFCN to the base station.

A method for reducing unnecessary attempts to receive other SIBs is as follows.

Currently, value_Tag is increased by 1 even if other SIB information is changed. However, for a terminal using a very long DRX cycle, not all SIB information is required. Therefore, a new value_Tag is defined only for the terminal. The new value_Tag is included in MIB or SIB1. The value_Tag is incremented by 1 when only the SIB information necessary for the UE using a very long DRX cycle is changed.

For example, SIB2 is regarded as access barring information and cell information, SIB3 and 4 are related to intra-freq neighbor information SIB3 and 5 are related to inter-freq information, and SIB14 is related to access barring information of MTC device. Therefore, when the SIB information is changed, the value of the newly defined value_Tag is increased by one.

On the other hand, SIB 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, etc. may be an unnecessary SIB for the terminal using a very long DRX cycle. Exactly the SIB type associated with the new value_Tag may be preset by the base station and inform the terminal, or may be predefined.

For the SIB2 change, we propose a method using separate indicators or value_tags included in MIB / SIB1.

The SI information required for a UE using a very long DRX cycle to receive a call is some information, not the entire information of SIB2. For example, PCCH / PDSCH configuration information. Therefore, the MIB or SIB1 includes a new indicator or a new value_Tag indicating that SI information in SIB2 required to receive a call is changed.

The last method is to send configuration information related to receiving a call to MIB or SIB1.

Seventh Example

The terminal requests allocation of transmission resources to the base station in order to transmit data on the uplink. For example, the terminal may request allocation of a transmission resource using a SR (Scheduling Request) transmission resource allocated thereto or may use a random access procedure. As an example, the Dedicated-Scheduling Request (D-SR) procedure defines an operation for requesting a transmission resource for transmitting uplink data using an SR transmission resource. The RA-SR (Random Access-Scheduling Request) procedure defines an operation for requesting a transmission resource for transmitting uplink data using a random access procedure.

The SR transmission resource may be set as part of a PUCCH transmission resource. The PUCCH transmission resource for the terminal may be configured by P_Cell or PUCCH S_Cell. Meanwhile, the UE may have one or more SR transmission resources at any time. In this case, the terminal should prepare a method of selecting an SR transmission resource to be used among one or more SR transmission resources.

For example, when a non-primary set is set in a terminal, the terminal and the base station may divide and process logical channels by sets. For example, a small amount of data is generated, such as VoIP, and a logical channel of a service having high sensitivity to transmission delay and jitter is processed through the serving cell of the primary set. However, logical channels of services that generate large amounts of data, such as FTP, can be handled through non-primary set serving cells.

In the following description, for convenience, a logical channel processed in the serving cell of the primary set is referred to as a 'primary set logical channel', and a logical channel processed in the serving cell of the non-primary set is referred to as a 'non-primary set'. Logical channel '.

Meanwhile, the base station informs the UE of which logical channel is the primary set logical channel and which logical channel is the non-primary set logical channel using a control message such as RRC connection reconfiguration. In this case, it is also possible to explicitly notify the non-primary set logical channel so that the remaining logical channel can be recognized as the primary set logical channel.

When a regular BSR is generated by data of an arbitrary logical channel, the terminal determines whether the BSR is triggered by a primary set logical channel or a non-primary set logical channel.

If triggered by the primary set logical channel, the UE triggers SR transmission of the P_Cell. However, if triggered by a non-primary set logical channel, it triggers SR transmission of PUCCH S_Cell.

Each time the UE transmits the SR, the associated SR_COUNTER is increased by one. If the SR is not canceled until the SR_COUNTER reaches a predetermined reference value, the terminal determines that the SR transmission has failed. The SR_COUNTER includes SR_COUNTER for P_Cell (hereinafter referred to as 'SR_COUNTER_P') and SR_COUNTER for PUCCH S_Cell (hereinafter referred to as 'SR_COUNTER_NP').

The terminal receives the dsr-TransMax and dsr-TransMax_NP from the base station. The dsr-TransMax is set while the non-primary set serving cell is set, and the dsr-TransMax_NP is set while the non-primary set serving cell is set.

On the other hand, when the SR transmission failure occurs, the terminal performs a differential operation according to the serving cell in which the SR transmission failure occurs.

FIG. 28 shows a control flow performed by a terminal to which an inter-ENB CA is set when SR transmission fails.

Referring to FIG. 28, when an SR transmission failure occurs, the UE determines whether an SR transmission failure occurs in P_Cell or PUCCH S_Cell (steps 2905 and 2910). For example, it is checked whether the SR transmission failure is determined by the result of comparing SR_COUNTER_P and dsr-TransMax or the result of comparing SR_COUNTER_NP and dsr-TransMax_NP.

The terminal proceeds to step 2915 when the SR transmission fails in the P_Cell (or primary set), and proceeds to step 2935 when the SR transmission fails in the PUCCH S_Cell (or non-primary set).

An SR transmission failure in the P_Cell means a problem in reverse transmission of the P_Cell. The failure of SR transmission in the PUCCH S_Cell means that a problem occurs in reverse transmission of the PUCCH S_Cell. For example, the problem may be a reverse transmission output setting error. In this case, it is necessary to take appropriate measures not only for the cell but also for the set.

The UE releases the PUCCH transmission resources of the P_Cell and releases the SRS transmission resources of all the serving cells of the primary set (or releases the SRS transmission resources of the P-TAG serving cells) (steps 2515 and 2920). The terminal releases the set transmission resource, that is, the set up backward grant and the set up forward assignment (step 2925). The terminal initiates random access in P_Cell (step 2930).

As described above, the SR transmission failure may be caused by a reverse transmission output setting error, and the reverse transmission output may be reset through power ramping of the random access process. The SR transmission failure may be due to a backward synchronization problem of the terminal. The reverse synchronization may also be reestablished through a random access procedure.

If the TA timer of the TAG to which the serving cell to which random access is to be performed is running at this point in time, the UE ignores the TA command received in the random access process, and thus, before starting random access in P_Cell in step 2930, Check if the TA timer of -TAG is running and stop the timer if it is running.

In step 2935, the terminal releases the PUCCH transmission resource of the PUCCH S_Cell. The UE releases SRS transmission resources of all serving cells of the corresponding non-primary set (or releases SRS transmission resources of serving cells belonging to the same TAG as the PUCCH S_Cell) (step 2940). The terminal generates an RRC control message reporting that an SR transmission failure has occurred in the PUCCH S_Cell (step 2945). The control message includes information on the identifier of the PUCCH S_Cell in which the SR transmission failed and information on the SR transmission output (for example, whether the average or maximum value of the transmission output applied to the SR transmission by the UE or the SR transmission output exceeds the maximum transmission output). Information, etc.) may be stored. The UE initiates a random access procedure in PUCCH S_Cell (step 2950). On the other hand, the UE checks whether the TA timer associated with the PUCCH S_Cell, that is, the TA timer of the TAG to which the PUCCH S_Cell belongs, is running before starting the random access.

Eighth Embodiment

In an eighth embodiment of the present invention, a terminal provides a method for reducing handover failure by transmitting and receiving control messages related to mobility with one or more cells.

29 illustrates a signaling procedure according to an eighth embodiment of the present invention.

Referring to FIG. 29, if a predetermined condition is met in the LTE network, the UE 3005 reports its performance to the serving base station 3010 (step 3025). The predetermined condition may be most representative when the base station requests a performance report from the UE.

The performance report message transmitted by the UE 3005 to report its performance to the serving base station 3010 includes a frequency band list supported by the terminal, a frequency band combination list supported by the terminal, and MIMO performance for each frequency band combination. Contains information.

In addition, the performance report message may further include information indicating whether the terminal supports the multi-cell RRC function. Here, the multi-cell RRC function is information indicating whether the UE can receive the RRC control message from the serving cell and neighbor cells (hereinafter referred to as 'secondary cells') that satisfy a predetermined condition.

Multi-cell RRC performance information for this is composed of the first information and the second information. The first information is information indicating whether the UE supports a multi-cell RRC function in an intra-frequency case when the forward center frequencies of the serving cell and the auxiliary cell are the same. The first information may be defined by one bit that is commonly applied to all frequency bands. The second information is information indicating whether the UE supports the multi-cell RRC function when the forward center frequencies of the serving cell and the auxiliary cell are different from each other (inter-frequency case). The second information may be represented by one bit for each frequency band combination of the 'frequency band combination list supported by the terminal'.

For example, if the second information is set to 'Yes' for any frequency band combination, it means that the UE supports the multi-RCC function even if the center frequencies of the serving cell and the auxiliary cell are different for the arbitrary frequency band combination.

Meanwhile, if a predetermined event occurs while the UE is currently transmitting / receiving data with the serving cell (or base station), the UE generates and transmits a measurement result message to the serving base station (step 3030). For example, the predetermined event may be a case in which a channel quality of an arbitrary neighbor cell satisfies a predetermined criterion.

In this case, the measurement result message may include information about an identifier of a cell whose channel quality satisfies a predetermined criterion, a forward center frequency, a channel quality of the cell, or a signal strength of a reference signal of the cell. For example, an identifier of a cell whose channel quality satisfies a predetermined criterion may be a physical layer cell identifier (PCI or Physical Cell Id).

The serving base station 3010 receives a measurement result message from the UE 3005. When the measurement result message is received, when the neighbor cell transmits forward data to the UE 3005, it is highly likely that the UE 3005 receives the forward data successfully.

For example, if the multi-cell RRC capability of the UE allows the transmission and reception of the RRC control message in the neighbor cell and the current serving cell, the serving base station 3010 determines to configure the neighbor cell as a secondary cell for the UE 3005 ( Step 3035). The serving base station 3010 transmits a control message to the base station managing the secondary cell (hereinafter referred to as an 'secondary base station') 3015 requesting to apply the multi-cell RRC function to the terminal (step 3040). . The control message may include an identifier (C-RNTI) of the terminal and information related to the channel state of the terminal.

The secondary base station 3015 determines whether to accept the request in consideration of the cell load situation and the C-RNTI allocation situation of the secondary cell. If it is decided to accept, the secondary base station 3015 sends a control message to the serving base station 3010 to accept the multi-cell RRC request. The control message includes C-RNTI information to be applied to the terminal. The C-RNTI may be the same as or different from the C-RNTI (hereinafter, referred to as 'C-RNTI 1') used by the UE in the serving cell.

If C-RNTI 1 is already in use in the secondary cell, the secondary base station 3015 may select one of the C-RNTIs that are not currently being used and store the control message. Hereinafter, the C-RNTI allocated to the UE by the secondary base station is referred to as 'C-RNTI 2'.

The serving base station 3010 generates a control message indicating the multi-cell RRC configuration and transmits it to the UE 3005 (step 3060). The control message includes information for specifying a secondary cell, C-RNTI 2 information, and information for specifying a search space.

For example, the information specifying the auxiliary cell is composed of information specifying the forward center frequency of the auxiliary cell and PCI information. In this case, C-RNTI 2 may or may not be included. For example, if C-RNTI 2 is not included, it means that C-RNTI 1 and C-RNTI 2 are the same.

The information specifying the search space is information for indicating which search space should be monitored when the UE monitors the PDCCH of the secondary cell. The search space is composed of a UE-specific search space and a common search space.

The terminal monitors both the terminal specific search space and the joint search space for the serving cell, and monitors only a part of the search spaces satisfying a predetermined condition among the terminal specific search spaces for the auxiliary cell. For example, the condition may be a search space having an aggregation level of more than a predetermined value. The search space is described in Specification 36.213. In this case, the search space related information may be related to an aggregation level. For example, if n is indicated as the search space related information in the configuration message, in monitoring the PDCCH of the auxiliary cell, the UE monitors only the search spaces having the aggregation level of n or more of the UE-specific search spaces using C-RNTI 2.

Upon receiving the control message, the UE 3005 acquires forward synchronization with respect to the secondary cell (step 3065). Here, acquiring forward synchronization with respect to the auxiliary cell means receiving a predetermined forward channel (for example, a synchronization channel) of the auxiliary cell to establish frequency synchronization and time synchronization.

When the forward synchronization is established, the terminal generates a control message containing the information that the multi-cell RRC configuration is successful and transmits to the serving cell (3070). The control message may include the latest measurement result for the secondary cell or channel quality indicator (CQI) information for the secondary cell.

After transmitting the control message, the UE simultaneously monitors PDCCHs of the serving cell and the auxiliary cell (3072). The UE applies C-RNTI 1 to the serving cell to monitor the UE-specific search space at all aggregation levels and the joint search spaces at aggregation level 4 and aggregation level 8, and applies C-RNTI 2 to the auxiliary cell, Monitor the terminal-specific search space at the aggregation level.

On the other hand, if the forward data is scheduled in the serving cell, that is, when the PDSCH addressed to the C-RNTI 1 is received in the serving cell, the UE applies the HARQ operation (3074). That is, the terminal decodes the PDSCH, transmits HARQ ACK if the decoding is successful, and transmits HARQ NACK if the decoding fails.

If forward data is scheduled in the secondary cell, that is, when the PDSCH addressed to C-RNTI 2 is received in the secondary cell, the UE does not apply the HARQ operation (3075). That is, the terminal decodes the PDSCH. If the decoding is successful, the terminal transmits the decoded data to a higher layer device, for example, an RRC device, and does not transmit HARQ feedback. However, if decoding fails, the corresponding data is discarded and HARQ feedback is not transmitted.

At any point in time, the serving base station determines to hand over the terminal to a predetermined cell. The serving base station transmits a control message (HANDOVER REQUEST) requesting handover to the base station of the handover candidate cell (3080). For convenience of explanation, it is assumed that the handover target cell and the auxiliary cell are the same cell. The handover request message includes an identifier of a terminal, information related to a bearer set in the terminal, security related information, and the like.

The target base station determines whether to accept the handover request. If it is determined to accept, a handover request response message (HANDOVER REQUEST ACK) is generated and transmitted to the serving base station (3085). The serving base station generates a handover command RRC control message (RRC connection reconfiguration) containing the handover request response message. In addition, a MAC-I (Message Authentication Code-Integrity) is generated and attached to the control message, and then a PDCP PDU is generated. The PDCP PDU containing the handover command is generated as a MAC PDU and transmitted to the UE (3087).

The serving base station transmits a handover command transmission request control message to the secondary base station (3090). The control message includes the MAC PDU containing the PDCP PDU containing the handover command and information related to the MCS level suitable for applying the MAC PDU transmission, or CQI information reported by the UE in step 3070. The MAC PDU may be the same as the MAC PDU transmitted in step 3087.

The secondary base station transmits the MAC PDU contained in the handover command transmission request control message to the terminal using C-RNTI 2 and a predetermined search space (3095).

When the terminal receives a handover command control message from one of the serving cell and the auxiliary cell, the terminal initiates a handover procedure by applying the information of the received handover command control message.

When the terminal receives the handover command control message from both the serving cell and the auxiliary cell, it first applies the information of the received handover control message to initiate a handover procedure. Late handover control messages received are ignored.

If the serving radio link state deteriorates to a state in which normal communication is impossible even before the base station commands a handover due to an unexpected error, the terminal is in a deadlock state in the current serving cell. In order to prevent this, the terminal continuously monitors the channel state of the current serving cell, and when a predetermined condition is met, the terminal controls its mobility on its own. This is called "radio link monitoring." When the multi-RCC function is configured or not, the terminal differentially applies the radio channel monitoring operation.

When the state in which the channel state of the serving cell is equal to or less than a predetermined criterion continues over a predetermined criterion, the terminal determines that a radio link problem is detected (radio link problem detection) (3105).

Wireless link abnormality detection condition,

'Asynchronous indicator occurs N310 times for the serving cell. The asynchronous indicator indicates that the PDCCH error rate calculated based on the reception quality of a predetermined channel or signal (for example, a cell reference signal) of the serving cell is a predetermined criterion, for example, 10% or more. For example, if it lasts longer than 200 ms. The UE acquires N310 from SIB2 of the serving cell. '

Can be

When the terminal detects an abnormal radio link, the terminal stops reverse transmission of the serving cell and drives a T310 timer. The T310 timer is broadcasted via SIB2 of the serving cell.

If the multi-RCC function is not configured in the terminal, the terminal monitors whether the serving cell is recovered while the T310 timer is running.

At this time, the radio link recovery condition,

'Sync indicator occurs N311 consecutive times for the serving cell. The synchronization indicator is a predetermined period of time when the PDCCH error rate calculated based on the reception quality of a predetermined channel or signal (eg, cell reference signal) of the serving cell is greater than or equal to a predetermined reference, for example, 5%. For example, if it lasts longer than 100 ms. The terminal acquires N311 from SIB2 of P_Cell. '

Can be

If the multi-RCC function is configured in the terminal, the terminal monitors whether the serving cell is recovered while the T310 timer is running and simultaneously monitors whether a handover command control message is received from the secondary cell. If the handover command control message is received in the secondary cell, the UE stops T310 and starts handover.

If the serving cell does not recover until T310 expires, the terminal declares a radio link failure and drives T311. And initiate the RRC connection reestablishment process. The RRC connection reestablishment process refers to a process in which the UE searches for a cell to resume communication, exchanges a predetermined RRC control message with the cell, and resumes the RRC connection. This is described in TS36.331 5.3.7.

If the multi-RCC function is configured in the terminal, the terminal monitors whether a handover command control message is received in the secondary cell while T311 is driven. If a handover command control message is received in the secondary cell, the terminal stops T311 and starts handover. The terminal preferentially selects a secondary cell in selecting a cell to resume communication.

When the terminal receives a predetermined RRC control message, the terminal performs an integrity check on the MAC-I of the received RRC control message. When the integrity check failure occurs, the UE checks whether the cell in which the received RRC control message is a serving cell or a secondary cell. If the RRC control message is received from the serving cell, the UE initiates an RRC connection reestablishment process. However, if the RRC control message is received from the secondary cell, the terminal discards the received RRC control message and does not start the RRC connection reestablishment process.

<Ninth Embodiment>

In general, MTC (Machine Type Communications) devices have a long communication period with the base station, and use a battery, without a continuous power supply. Representative MTC devices

Meters, sensors, etc. exist. Therefore, efficient power usage is a very important issue in the MTC device. The present invention proposes a method for facilitating paging reception when a very long DRX cycle is used so that the MTC device can efficiently use power.

FIG. 31 is a diagram for explaining a problem of failing to check newly updated system information (hereinafter, referred to as 'SI') when a very long DRX cycle is applied to save power consumption of an MTC device. to be.

If the SI information is changed in the SI change checking and updating method, the UE informs the terminal that the SI information is to be changed during the preset modification period 3210. The paging is received in an active time period (3200) that arrives every DRX cycle, the terminal recognizes that the SI information will change soon.

Thereafter, the SI information 3215 changed in the next modification period is broadcast. Typically, the LTE standard defines 2.56 seconds as the maximum DRX cycle. Therefore, even if a DRX cycle of up to 2.56 seconds is applied, the modification period is set so that the terminal can receive the paging.

If a very long DRX cycle 3220 is applied to save power consumption of the MTC device, the MTC device may not receive paging indicating whether the SI has been changed. This then causes the MTC device to use incorrect SI information when the active time 3225 arrives and receives the paging. Therefore, one way to prevent this is to continuously send the paging to the MTC device for a period equal to or longer than the very long DRX period, so that even if a very long DRX cycle is applied, the MTC device can receive a paging indicating SI change. To transmit. However, this is not a preferred method because it will cause very large signaling overhead. Accordingly, in the present invention, when a very long DRX cycle is applied, the MTC device wakes up before the paging reception timing and proposes a method of receiving SI information.

32 is a diagram for explaining conditions to which the present invention is applied.

Referring to FIG. 32, in operation 3300, the MTC device determines whether a very long DRX cycle is applied to save power consumption. If the very long DRX cycle is not applied, the SI update and paging reception operations are performed by the general method in step 3305. However, if a very long DRX cycle is applied, in step 3310 the newly proposed method is applied.

For example, the embodiment proposed by the present invention is characterized by the following matters.

First, the very long DRX period set by the predetermined method is set longer than the modification period.

When the second very long DR period is applied, the UE wakes up earlier than the paging reception timing to perform cell selection or reselection, and then receives SI information.

Third, the wake-up time may be set from a base station or set to a predetermined time or a predetermined time as a terminal implementation.

Fourthly, in the SI information receiving operation, in order to save the reception time, a new indicator is included in SIB1, and based on this, it is determined whether to receive SIB information after SIB1.

Fifth, the indicator is used only by a terminal that applies a very long DRX cycle, and as SI information is changed, increases by 1 within a specific range, and information of SIB14 including at least EAB (Extended Access Barring) is changed. It is characterized by reflecting whether or not.

33 is a first embodiment of a method in which an MTC device wakes up before a paging reception timing and receives SI information. In this embodiment, when a very long DR period is applied, the UE wakes up earlier than the paging reception timing to perform a cell selection or reselection operation. Subsequently, in the SI information reception operation, a new indicator is included in SIB1 to save reception time. .

Referring to FIG. 33, in step 3410, the UE 3400 receives SIB1 information from the base station 3405. The SIB1 includes a newly defined indicator, systemInfoValueTagforMTC. Unlike the existing value tag, the indicator increases the value by 1 within a specific range even when SIB14 including at least EAB information is changed.

If the SI value is continuously increased by 1 and reaches the maximum value, the indicator value reaching the maximum value is reset to '0' which is the lowest value. The EAB information indicates whether to allow access of MTC devices. Therefore, the change of EAB information is important information for MTC devices applying a very long DRX cycle.

However, the value tag indicator indicating the change of the existing SI information does not reflect the change of SIB14. In addition, the newly defined indicator is characterized by ignoring the terminal does not apply a very long DRX cycle.

The terminal records the received indicator information in step 3415. The terminal also receives the remaining SIBs in step 3420 and stores the SI information in step 3425. In step 3430, the terminal and the base station apply a very long DRX cycle according to a predetermined method. Here, a very long DRX cycle means at least a specific value having a period longer than the conventional 2.56 seconds. The specific value may be set or a predetermined value. In step 3435, the UE applies the very long DRX cycle determined above.

And if the very long DRX cycle is applied in step 3440, the terminal wakes up before the incoming paging reception timing. The waking time 3480 before the paging reception is a time set by the base station or a predetermined time or a terminal implementation.

If a very long DRX cycle is used, the UE performs a cell selection or cell reselection process in step 3445. During the very long DRX cycle, since the terminal cannot perform channel measurement, it is necessary to confirm whether the mobile station and whether a suitable cell capable of communication are still the previous serving cell.

Therefore, in the embodiment of the present invention, a terminal using a very long DRX cycle essentially performs a process of newly finding a suitable cell before paging reception timing.

The terminal receives the MIB in step 3450, and receives the SIB1 in step 3455. The SIB1 includes the aforementioned indicator. The case where the indicator is not included or the method is not used is already described in the second embodiment. In step 3460, the UE uses a very long DRX cycle, and if the newly found suitable cell is a previous serving cell and the indicator value is the same as the previously recorded indicator value, the UE does not receive SIBs after SIB1. This is because it means that the SI information held by the terminal has not been newly updated.

Otherwise, the terminal receives necessary SIBs in step 3465. If the SIBs exist, the existing SIBs include at least SIB14. The terminal stores the previously received SI information in step 3470. In step 3475, the terminal receives the paging using the stored SI information.

34 illustrates a second embodiment of a method in which an MTC device wakes up before a paging reception timing and receives SI information. In the present embodiment, when a very long DR period is applied, the UE wakes up earlier than the paging reception timing to perform cell selection or reselection, and then performs SI information reception.

Referring to FIG. 34, the terminal 3500 receives SIB1 information from the base station 3505 in step 3510 and receives the remaining SIBs in step 3515. The terminal stores SI information in step 3520. In step 3525, the terminal and the base station apply a very long DRX cycle. For example, the UE applies a very long DRX cycle determined in operation 3525. If a very long DRX cycle is applied in step 3530, the UE wakes up before the incoming paging reception timing. The waking time 3575 before the paging reception is a time set by the base station or a predetermined time or a terminal implementation.

If a very long DRX cycle is used, the UE performs a cell selection or cell reselection process in step 3535. During a very long DRX cycle, since the UE cannot perform channel measurement, it is necessary to check whether the UE is moved and whether a suitable cell capable of communication is still the previous serving cell.

Therefore, in the embodiment of the present invention, the UE using a very long DRX cycle is characterized in that the process of newly searching for a suitable cell before the paging reception timing is essentially performed. In addition, the second embodiment is characterized in that all the SIBs required for the MTC device are received without using an indicator as in the first embodiment.

To this end, the terminal receives the MIB in step 3545, and receives the SIB1 in step 3550. In addition, SIB information required for the actual MTC device, for example, SIB2 and SIB14, etc. are additionally received. Since much time is not required to receive such SIBs, the usefulness of the indicator in the first embodiment may not be so great. In addition, the complexity of introducing a new indicator has the advantage.

The terminal receives necessary SIBs after SIB1 in step 3560. The terminal stores the SI information received in step 3565. In step 3570, the terminal receives the paging using the stored SI information.

19 is a block diagram of a user terminal according to an exemplary embodiment of the present invention.

Referring to FIG. 19, a UE includes a transceiver 1905, a controller 1910, a multiplexing and demultiplexing unit 1915, a control message processing unit 1930, and various upper layer processing units 1920 and 1925.

The transceiver 1905 receives data and a predetermined control signal through a forward channel of a serving cell and transmits data and a predetermined control signal through a reverse channel. When a plurality of serving cells are set, the transceiver 1905 transmits and receives data and control signals through the plurality of serving cells.

The multiplexing and demultiplexing unit 1915 multiplexes data generated by the upper layer processing unit 1920 and 1925 or the control message processing unit 1930, or demultiplexes the data received by the transmitting and receiving unit 1905 so that the appropriate upper layer processing unit 1920, 1925 or the control message processor 1930.

The control message processing unit 1930 is an RRC layer device and processes the control message received from the base station and takes necessary actions. For example, the RRC control message is received and S_Cell related information is transmitted to the controller.

The higher layer processors 1920 and 1925 may be configured for each service. Data generated from user services such as FTP (File Transfer Protocol) or Voice over Internet Protocol (VoIP) can be processed and delivered to the multiplexing and demultiplexing unit 1915 or the data transferred from the multiplexing and demultiplexing unit 1915 Process it and pass it to the higher-level service application.

The control unit 1910 checks scheduling commands received through the transceiver 1905, for example, backward grants, and the transceiver 1905 and the multiplexing and demultiplexing unit 1915 to perform reverse transmission on the appropriate transmission resource at an appropriate time. ). The controller also manages various procedures for S_Cell configuration, various procedures for activation / deactivation, and various procedures related to the multi-cell RRC function. More specifically, FIGS. 10, 11, 12, 15, 16, 17, 18, 21, 22, 23, 24, 25, 26, 27, 28, and 29 A control operation necessary for a terminal operation illustrated in FIG. 30 and the like is performed.

20 shows a configuration of a base station according to an embodiment of the present invention.

Referring to FIG. 20, the base station includes a transceiver 2005, a controller 2010, a multiplexing and demultiplexing unit 2020, a control message processing unit 2035, various upper layer processing units 2025 and 2030, and a scheduler 2015. It includes.

The transceiver 2005 transmits data and a predetermined control signal through a forward carrier and receives data and a predetermined control signal through a reverse carrier. When a plurality of carriers are set, the transceiver 2005 performs data transmission and reception and control signal transmission and reception to the plurality of carriers.

The multiplexing and demultiplexing unit 2020 multiplexes data generated by the upper layer processing units 2025 and 2030 or the control message processing unit 2035, or demultiplexes the data received by the transmitting and receiving unit 2005 so that the appropriate upper layer processing unit 2025, 2030, the control message processor 2035, or the controller 2010. The control message processing unit 2035 processes a control message transmitted by the terminal to take necessary actions, or generates a control message to be transmitted to the terminal and delivers the control message to the lower layer.

The upper layer processing units 2025 and 2030 may be configured for each bearer, and the data transmitted from the S-GW or another base station may be configured as an RLC PDU and transmitted to the multiplexing and demultiplexing unit 2020 or the multiplexing and demultiplexing unit 2020. RLC PDU delivered from the C-PW) is configured as a PDCP SDU and transmitted to the S-GW or another base station.

The scheduler allocates a transmission resource to the terminal at an appropriate time point in consideration of the buffer state and the channel state of the terminal, and processes the signal transmitted by the terminal to the transceiver or transmits the signal to the terminal.

The EPS bearer device is configured for each EPS bearer, and processes the data transmitted from the upper layer processor and delivers the data to the next network node.

The controller manages all procedures for S_Cell configuration, various procedures for activation / deactivation, and various procedures related to the multi-cell RRC function. More specifically, the base station related to the terminal operation illustrated in FIGS. 10, 11, 12, 15, 16, 17, 18, 21, 22, 23, 28, 29, and 30 may be Control the actions to be performed.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but those skilled in the art may be embodied by various modifications without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below, but also by the equivalents of the claims. In addition, these modifications should not be individually understood from the technical spirit or prospect of the present invention.

Claims (18)

In the method for providing a broadcast service based on a plurality of frequency bands in a terminal of a mobile communication system,
Determining whether a frequency band combination supported by the terminal includes a frequency band of a frequency for a broadcast service to be received at the terminal;
When the supported frequency band combination includes the frequency band, transmitting a control message including identification information corresponding to a frequency for the broadcast service to be received at the terminal to a base station; And
Receiving user service information (USD) defining a mapping relationship between the broadcast service and a service area identifier (SAI),
The user service information may be received through a short message service (SMS), a multimedia message service (MMS), or an internet protocol (IP) multimedia subsystem (IMS),
The identification information includes information associated with a center frequency of the frequency at which the broadcast service is to be received,
The information associated with the center frequency is selected based on the size of frequency band identifiers corresponding to frequency bands including the frequency at which the broadcast service is to be received.
The method of claim 1,
The determining operation is
Identifying whether a system information block (SIB) provided from a serving cell includes the identification information corresponding to the broadcast service;
When the system information block includes the identification information, determining whether to support a frequency band corresponding to at least one frequency included in the system information block for the identification information; And
Identifying the frequency information corresponding to the at least one frequency when the frequency band is supported,
The identification information included in the control message includes the frequency information.
The method of claim 2,
And when the system information block includes a plurality of frequency information corresponding to the identification information, one frequency information selected from the plurality of frequency information is reported to the base station through the control message.
The method of claim 3,
The information related to the center frequency is characterized in that the EUTRA absolute radio frequency channel number (EARFCN).
The method of claim 4, wherein
The determining operation is
And determining whether the broadcast service is received by using start time information of the broadcast service included in the user service information.
The method of claim 1,
Wherein the center frequency belongs to two frequency bands among frequency bands included in the frequency band combination,
Selecting one frequency band of the two frequency bands.
A terminal for providing a broadcast service based on a plurality of frequency bands in a mobile communication system,
Transceiver; And
If the frequency band combination supported by the terminal includes a frequency band of a frequency for a broadcast service to be received at the terminal, and the supported frequency band combination includes the frequency band, the transceiver User service information for controlling to transmit a control message including identification information corresponding to a frequency for the broadcast service to a base station, wherein the transceiver defines a mapping relationship between the broadcast service and a service area identifier (SAI); Processor to control receiving (USD, user service description),
The user service information is received through a short message service (SMS), a multimedia message service (MMS), or an internet protocol (IP) multimedia subsystem (IMS),
The identification information includes information associated with a center frequency of the frequency at which the broadcast service is to be received,
And the information associated with the center frequency is selected based on a size of frequency band identifiers corresponding to frequency bands including the frequency to which the broadcast service is to be received.
The method of claim 7, wherein
The processor identifies whether a system information block (SIB) provided from a serving cell includes the identification information corresponding to the broadcast service, and when the system information block includes the identification information, It is possible to determine whether to support a frequency band corresponding to at least one frequency included in the system information block for the identification information, and if the frequency band is supported, identify frequency information corresponding to the at least one frequency. Characterized by
The identification information included in the control message includes the frequency information.
The method of claim 8,
In the case where the system information block includes a plurality of frequency information corresponding to the identification information, the processor selects one frequency information among the plurality of frequency information and controls the selected one frequency information. Terminal for reporting to the base station via a message.
The method of claim 9,
The information associated with the center frequency is characterized in that the UETRA absolute radio frequency channel (EARFCN).
The method of claim 10,
The processor,
And determining whether the broadcast service is received by using start time information of the broadcast service included in the user service information.
The method of claim 7, wherein
Wherein the center frequency belongs to two frequency bands among frequency bands included in the frequency band combination,
The processor is characterized in that for selecting one frequency band of the two frequency bands.
A method for providing a broadcast service by a serving cell supporting a plurality of frequency bands in a mobile communication system,
A system information block (SIB) including broadcast service related information, including service area identification (SAI) and frequency information corresponding to each of at least one broadcast service provided from the serving cell; Transmitting;
Receiving a control message from a terminal, the control message including identification information corresponding to a frequency of a broadcast service identified based on the broadcast service related information included in the system information block; And
Receiving user service information (USD) defining a mapping relationship between the broadcast service and the service area identifier,
The user service information may be transmitted through a short message service (SMS), a multimedia message service (MMS), or an internet protocol (IP) multimedia subsystem (IMS).
Wherein the identification information includes information associated with a center frequency of a frequency at which the identified broadcast service is to be provided,
The information associated with the center frequency is selected based on the size of frequency band identifiers corresponding to frequency bands including the frequency to which the identified broadcast service is to be provided.
The method of claim 13,
The user service information, characterized in that it comprises the start time information for each of the at least one broadcast service provided from the serving cell.
The method of claim 13,
Wherein the center frequency belongs to two frequency bands among frequency bands included in the frequency band combination,
Wherein one frequency band is selected from the two frequency bands.
A serving cell for providing a broadcast service based on a plurality of frequency bands in a mobile communication system,
A transceiver; And
The transceiver unit may include a system information block (SIB) including broadcast service related information including a service area identifier (SAI) and frequency information corresponding to each of at least one broadcast service to be provided. When a control message is controlled to be transmitted and a control message is received from a terminal, the control message including identification information corresponding to a frequency of a broadcast service identified based on the broadcast service related information included in the system information block is received. And a processor for providing a broadcast service and controlling the transceiver to transmit user service information (USD) defining a mapping relationship between the broadcast service and the service area identifier.
The user service information may be transmitted through a short message service (SMS), a multimedia message service (MMS), or an internet protocol (IP) multimedia subsystem (IMS).
Wherein the identification information includes information associated with a center frequency of a frequency at which the identified broadcast service is to be provided,
And the information associated with the center frequency is selected based on the size of frequency band identifiers corresponding to frequency bands including the frequency to which the identified broadcast service is to be provided.
The method of claim 16,
And the user service information includes start time information for each of the at least one broadcast service provided from the serving cell.
The method of claim 16,
Wherein the center frequency belongs to two frequency bands among frequency bands included in the frequency band combination,
A serving cell, characterized in that one frequency band is selected from the two frequency bands.

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