KR20110023797A - Method for communication using carrier switching in mobile communication system supporting multiple carrier - Google Patents

Abstract

PURPOSE: A communication method using carrier switching in a wireless communication system supporting multi carriers is provided to switch different carriers, thereby operating a terminal without data and service delay or interruption. CONSTITUTION: A terminal transmits a switching request message indicating what E-MBS service is desired to base station(S410). The base station transmits a switching response message to a terminal(S420). The switching response message includes information about switching timing among carriers set in a terminal. The terminal switches a carrier from the second carrier to the first carrier by referring to a switching response message. The terminal receives data from the base station through the first carrier after the switching timing(S430).

Description

Communication method using carrier switching in wireless communication system supporting multicarrier {METHOD FOR COMMUNICATION USING CARRIER SWITCHING IN MOBILE COMMUNICATION SYSTEM SUPPORTING MULTIPLE CARRIER}

The present invention relates to a wireless communication system supporting multiple carriers between a terminal and a base station. More particularly, the present invention relates to a communication method using carrier switching for a terminal that cannot process a plurality of carriers at the same time.

3rd Generation Partnership Project (3GPP) long term evolution (LTE) and Institute of Electrical and Electronics Engineers (IEEE) 802.16m are being developed as candidates for the next generation wireless communication system. The 802.16m specification implies two aspects: past continuity, a modification to the existing 802.16e specification, and future continuity, a specification for the next generation of IMT-Advanced systems. Accordingly, the 802.16m standard requires all the advanced requirements for the IMT-Advanced system to be maintained while maintaining compatibility with the Mobile WiMAX system based on the 802.16e standard.

Wireless communication systems generally use one bandwidth for data transmission. For example, the second generation wireless communication system uses a bandwidth of 200KHz ~ 1.25MHz, the third generation wireless communication system uses a bandwidth of 5MHz ~ 10MHz. In order to support increasing transmission capacity, recent 3GPP LTE or 802.16m continues to expand its bandwidth to 20 MHz or more. In order to increase the transmission capacity, it is necessary to increase the bandwidth. However, even when the level of service required is low, supporting a large bandwidth can cause a large power consumption.

Accordingly, a multi-carrier system has emerged that defines a carrier having one bandwidth and a center frequency and enables data transmission and / or reception over a wide range of carriers over a plurality of carriers. By using one or more carriers, both narrow and wide bandwidths are supported simultaneously. For example, if one carrier corresponds to a bandwidth of 5 MHz, four carriers are used to support a maximum bandwidth of 20 MHz.

The IEEE 802.16m system supports Enhanced Multicast Broadcast Service (E-MBS). E-MBS is a point-to-multipoint system in which data packets are simultaneously transmitted from one source to multiple destinations. Broadcast means the ability to deliver content to all users. Multicast refers to content directed to a specific group of users subscribed to receive a specific service. Static multicast and dynamic multicast may be supported.

In a multi-carrier system, that is, a system in which a plurality of uplink carriers and a plurality of downlink carriers are used, an efficient switching method is required to smoothly provide an E-MBS service when a terminal cannot process a plurality of carriers.

An object of the present invention is to provide a data transmission method using carrier switching in a wireless communication system supporting multiple carriers.

In one aspect, a data transmission method by a base station in a multicast broadcast service (MBS) supporting a multi-carrier in a wireless communication system is a step of receiving a switching request message from the terminal indicating which E-MBS service the terminal requires ; Transmitting a switching response message including information on a switching time between a plurality of carriers set in the terminal to the terminal; And transmitting data regarding the E-MBS service target from the switching time point to the terminal through the primary carrier.

In another aspect, a method of receiving data by a terminal in an MBS supporting multiple carriers in a wireless communication system includes the steps of: transmitting a switching request message indicating which E-MBS service the terminal requires; Receiving a switching response message from the base station, the switching response message including information on a switching time between a plurality of carriers set in the terminal; Switching from a secondary carrier to a primary carrier at the switching time point; And receiving data regarding the E-MBS service object from the base station through the primary carrier.

For E-MBS services supporting multi-carrier operation, different carriers may be switched to operate without delay or disconnection of data and services.

1 shows a wireless communication system.
2 shows an example of a protocol structure for supporting multiple carriers.
3 shows an example of a frame structure for multi-carrier operation.
4 is a flowchart illustrating a carrier switching process according to the present invention.
5 shows an example of a switching interval according to the present invention.
6 shows that the reverse switching point in time according to the present invention is earlier or delayed than the original point in time.
Figure 7 illustrates to advance or delay the switching time point in accordance with the present invention.
8 shows an example of the base station to inform the switching information through the MBS MAP.
9 shows an example of informing switching information through an MBS MAP in a superframe.
10 shows an example of a case where the MBS MAP includes information of a plurality of switching.

1 shows a wireless communication system. The wireless communication system 10 includes at least one base station (BS) 11. Each base station 11 provides a communication service for a particular geographic area (generally called a cell) 15a, 15b, 15c. The cell may again be divided into multiple regions (referred to as sectors). The mobile station (MS) 12 may be fixed or mobile, and may include a user equipment (UE), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, and a PDA. (personal digital assistant), wireless modem (wireless modem), a handheld device (handheld device) may be called other terms. The base station 11 generally refers to a fixed station communicating with the mobile station 12, and may be referred to as other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, and the like. have. Hereinafter, downlink means communication from the base station to the terminal, and uplink means communication from the terminal to the base station. In downlink, a transmitter may be part of a base station and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal and a receiver may be part of a base station.

The size (ie bandwidth) of the multiple carriers may be different. For example, assuming that five carriers are used for the configuration of the 70 MHz band, 5 MHz carrier (carrier # 0) + 20 MHz carrier (carrier # 1) + 20 MHz carrier (carrier # 2) + 20 MHz carrier (carrier # 3) It may be configured as a + 5MHz carrier (carrier # 4).

A multiple carrier system (MCS) refers to a system that supports multiple carriers based on spectral aggregation.

2 shows an example of a protocol structure for supporting multiple carriers. The common medium access control (MAC) entity 210 manages a PHY layer 220 using a plurality of carriers. The MAC management message transmitted to a specific carrier may be applied to other carriers. The PHY layer 220 may operate in time division duplex (TDD) and / or frequency division duplex (FDD).

3 shows an example of a frame structure for multi-carrier operation. A superframe consists of four radio frames F0, F2, F3, F3, and each radio frame consists of eight subframes. The subframe includes a plurality of OFDM symbols. The superframe header (SFH) is located in the first subframe in the superframe. The SFH is a unit in which several frames are transmitted, and mainly includes essential system parameters and system configuration information and is transmitted to the terminal. P-SFH (Primary SFH) and S-SFH (secondary SFH) is divided into, P-SFH is mainly transmitted in every superframe unit. P-SFH defines whether the S-SFH is transmitted or not, and the period can be transmitted in one or more superframe units. Each carrier may have its own SFH. The SFH is transmitted over the broadcast channel and carries the essential system parameters. Some carriers may have only part of the SFH. The multicarriers may or may not be adjacent to each other. The terminal may support one or more carriers according to its capability.

The carriers may be divided into a fully configured carrier and a partially configured carrier according to directionality. The preset carrier is a bidirectional carrier and refers to a carrier capable of transmitting and / or receiving all control signals (synchronization, broadcast, multicast, unicast control signals) and data. It is possible to apply to all the single-carrier terminal. The partially configured carrier refers to a carrier capable of transmitting only downlink data in a unidirectional carrier, and refers to a downlink carrier that is not paired with a downlink carrier in the TDD scheme or an uplink carrier in the FDD scheme. The partial set carrier may be mainly used for a multicast and broadcast service (MBS) and / or a single frequency network (SFN), but the terminal cannot perform network entry or handover with the partial set carrier.

The carriers may be divided into a primary carrier and a secondary carrier according to activation. The primary carrier is a carrier that is always active. The carrier is a carrier wave in which traffic and a PHY / MAC control signal are transmitted between the base station and the terminal. Even though the base station supports multiple carriers, the terminal receiving the service from the base station is in a single carrier mode. In the single carrier mode, communication is performed using only one carrier. A secondary carrier is a carrier that is activated / deactivated according to a specific condition. The secondary carrier is an additional carrier wave to the primary carrier, and a carrier to which special commands or rules used for the transmission of traffic or indicated by the primary carrier are applied. Here, activation means that transmission or reception of traffic data is performed or in a ready state. Deactivation means that transmission or reception of traffic data is impossible, and measurement or transmission of minimum information is possible.

In one common MAC of a multi-carrier system, radio resources are made through a primary carrier and one or more secondary carriers. However, full control of mobility, state, and context of the terminal is performed only through the primary carrier.

The terminal may use only one primary carrier or one or more secondary carriers in addition to the primary carrier. The terminal may be assigned a primary carrier and / or a secondary carrier from the base station. The primary carrier may be a preset carrier file, and is a carrier through which main control information is exchanged between the base station and the terminal. The secondary carrier may be a preset carrier or a partially configured carrier file, and is a carrier assigned according to a request of a terminal or an indication of a base station.

The primary carrier may be used for network entry and / or allocation of secondary carriers of the terminal. The primary carrier may be selected from among preset carriers rather than being fixed to a specific carrier. A carrier set as a secondary carrier can also be changed to a primary carrier.

Hereinafter, carrier switching will be described.

In a wireless communication system supporting multiple carriers, it is possible to switch the corresponding physical layer connection of the terminal from the primary carrier to the secondary carrier or from the secondary carrier to the primary carrier according to the instruction of the base station. . This is called carrier switching. In particular, carrier switching occurs frequently when the secondary carrier is a partial carrier. When the terminal is connected to the secondary carrier for a certain period, the terminal does not need to maintain the physical layer connection with the primary carrier.

Carrier switching may be performed by a MAC management message transmitted on a primary carrier in a periodic or event-triggered manner. When the terminal is switched to the secondary carrier, the primary carrier of the terminal provides basic information such as timing (timing), frequency adjustment (frequency adjustment) for synchronization with the secondary carrier.

In the MAC management message transmitted by the UE to switch carriers, various pieces of information are transmitted through a carrier, which includes a target partial set carrier, a switching mode, a start time, a switching interval, and a switching interval. Switching period.

The switching mode refers to either a periodic switching mode or an event-triggered switching mode. The switching time point refers to a time point for switching from one carrier to another carrier and may be expressed by a superframe number. The switching interval refers to the time to stay in the carrier after being switched. For example, when switching from the primary carrier to the secondary carrier, it is the time to stay in the secondary carrier. The switching period corresponds to a periodic type of switching, and refers to the time from the previous switching time to the next switching time. The switching interval or switching period may be expressed in units of superframes.

When switching from the primary carrier to the secondary carrier, it is possible to switch from the secondary carrier to the primary carrier again after the switching period, which is called reverse switching. On the contrary, when switching from the secondary carrier to the primary carrier, reverse switching is to switch from the primary carrier to the secondary carrier again after the switching period passes.

When an E-MBS service is provided in a multi-carrier system, a section having a predetermined pattern in which several frames are simultaneously transmitted is called an MBS Scheduling Interval (hereinafter, referred to as an 'MSI'). At least one control channel is present in the MSI section, and the superframe header mainly instructs the user to find the location and area of the control channel. The control channel may include an MBS MAP. MBS MAP indicates where the MBS data burst is located.

In the E-MBS service of a general multi-carrier system, carrier switching is performed by instructing a corresponding switching time, switching interval, and switching period from a base station to a terminal. However, considering the transmission of data for the uplink of the terminal and the E-MBS service, it is necessary to further segment and efficiently switch.

Hereinafter, the switching from the secondary carrier to the primary carrier according to the present invention will be described. In the case of the E-MBS service, since the base station often transmits data unilaterally to a plurality of terminals at the same time, it is often a partial set carrier supporting downlink and a service is performed through a carrier which is a secondary carrier. In the case of the secondary carrier, it may be necessary to perform carrier switching from the secondary carrier to the primary carrier because uplink transmission from the terminal to the base station cannot be performed. However, the scope of the invention is not limited thereto.

The base station may calculate the switching start time and inform the terminal through the DSA process. However, if the base station calculates the switching start time but there is no time available, the base station may receive a request from the terminal. Even before switching to the primary carrier, that is, even when data is being transmitted on the secondary carrier, the base station may be requested to start switching from the terminal. At this time, the base station may monitor while keeping the uplink control channel (UL control channel) that can receive the signal of the terminal. The uplink control channel may exist in the primary carrier or may exist in the secondary carrier.

4 is a flowchart illustrating a carrier switching process according to the present invention.

Referring to FIG. 4, the terminal transmits a switching request message indicating which E-MBS service is requested to the base station (S410). The base station transmits a switching response message including information on the switching time between the plurality of carriers set in the terminal (S420). After the UE switches the carrier from the secondary carrier to the primary carrier at the switching time point with reference to the switching response message, the terminal receives data from the base station through the primary carrier from the switching time point (S430). After the switching period, the reverse switching may be performed again from the primary carrier to the secondary carrier.

When the carrier switching is performed as described above (eg, when the carrier switching mode is 0b1), the terminal may inform the base station which E-MBS service (or content) is to be received through the switching request message. . For example, the switching request message may be an E-MBS-REP message. After receiving the switching request message, the base station calculates the interval in which the terminal can perform unicast scheduling on the primary carrier, in this case, may use the E-MBS connection bitmap (connection bitmap) of the switching request message. The base station schedules the unicast service of the terminal through the primary carrier based on the valid period calculated using the E-MBS connection bitmap in the switching request message. When the UE changes the concurrently receiving E-MBS service, it transmits a switching request message including the updated E-MBS connection bitmap.

The switching request message is transmitted from the terminal to the base station if one of the following conditions is satisfied.

1. When the terminal requests a start time for switching to the E-MBS carrier after the DSA, DSC or DSD transaction from the base station.

2. When updating an indication on the E-MBS stream received by the current UE without releasing the allocated E-MBS connection through the DSA-REQ or DSA-RSP message.

3. When the UE indicates a time for stopping E-MBS carrier switching without releasing the allocated E-MBS connection through the DSA-REQ or DSA-RSP message.

The switching request message may be transmitted through at least one of ranging, subheader, existing MAC management message, new MAC management message, or control channel.

Table 1 below shows an example of a switching request message.

Attributes / Array of attributes Size (bits) Value / Notes Conditions MAC Control Message Type 8 AAI_E-MBS-REP message E-MBS Zone ID 7 Indicates E-MBS Zone from which the AMS is currently receiving E-MBS data Report Mode 2 Indicates the AMS starts / changes / ends E-MBS
0b00: AMS requests ABS to assign a carrier switching start time
0b01: AMS updates E-MBS connection Bitmap
0b10: AMS ends E-MBS carrier switching
0b11: reserved E-MBS Connection Bitmap 16 Each bit of the bitmap represents an E-MBS connection for which service flows have been established using AAI-DSx transactions in one E-MBS Zone.
The E-MBS service (s) are mapped in ascending order of their E-MBS ID + FID value from LSB to MSB of the bitmap.
For each bit:
Value 0: The AMS does not intend to receive the E-MBS service.
Value 1: The AMS currently receives E-MBS or the AMS may switch to this service in the near future. Shall be included if the value of Report Mode is 0b01.

Referring to Table 1, the E-MBS connection bitmap may include 16 bits as an example, and may be included when the report mode is 0b01. Each bit of the E-MBS connection bitmap represents an E-MBS connection in which a service flow is generated using DSA, DSC, or DSD processing in one E-MBS zone. The E-MBS service is mapped from the LSB to the MSB of the bitmap in the ascending order of the sum of the E-MBS ID and the FID value. If each bit is 0, the terminal does not receive the E-MBS service, and if 1, the terminal switches to receive the E-MBS or to receive it in the near future.

The base station receiving the switching request message through the uplink control channel or the like responds with the switching response message. At this time, the base station refers to the E-MBS service (or content) that the terminal receives through the switching request message or the E-MBS service (or content) that the terminal intends to receive, and in units of actual E-MBS service (or content). The switching response message is transmitted to perform carrier switching. In particular, the MBS MAP defining the E-MBS service (or content) may inform the time, period, and time of switching the carrier back to the primary carrier in the MBS MAP. The switching response message may be called an E-MBS-RSP message.

Table 2 below shows an example of a switching response message.

Attributes / Array of attributes Size (bits) Value / Notes Conditions MAC Control Message Type 8 AAI_E-MBS-RSP message Carrier Switching Start time 4 4 LSBs of superframe number at which the AMS switches carrier to receive E-MBS Present when the report mode in AAI_E-MBS-REP message is 0b00 Unicast Available Interval Bitmap Variable Indicates when the AMS should be available in the primary carrier using N bits b _o b ₁ b ₂ ... b _{N -1 1}
If b _i == 0, then AMS is available for E-MBS data scheduling in secondary carrier
If b _i == 1, then AMS is available for unicast scheduling in primary carrier

N _MSI = 2 superframes: N = 4 bits
N _MSI = 4 superframes: N = 4 bits
N _MSI = 8 superframes: N = 8 bits
N _MSI = 16 superframes: N = 16 bits
Depending on the N _MSI , the number of bits per subframe changes
If N _MSI = 2, then 2 frames per bit
If N _MSI = 4, 8 and 16, then 4 frames per bit Present when the report mode in AAI_E-MBS-REP message is 0b01

Referring to Table 2, the switching response message includes a unicast available interval bitmap, and the unicast valid interval bitmap is available to the terminal on the primary carrier using an N bit bitmap. Indicates whether or not. That is, it indicates whether the terminal can receive a control signal through the primary carrier. For example, if each bit of the unicast valid interval bitmap is 0, the UE is effective for E-MBS data scheduling on the secondary carrier, and if 1, unicast scheduling is valid on the primary carrier. The size of the unicast valid interval bitmap may vary according to the number of MSI superframes.

After the terminal receives the switching response message and switches the carrier from the secondary carrier to the primary carrier at the switching time, the terminal receives data from the base station through the primary carrier from the switching time. The switching interval may be reverse-switched again from the primary carrier to the secondary carrier after the switching interval, which is a time remaining in the carrier after being switched.

In the meantime, the switching period may be an MSI cycle or a transmission cycle of the MBS MAP.

5 shows an example of a switching interval according to the present invention. The switching interval consists of four superframes. The MBS MAP 501 is transmitted in the first superframe, and the MBS MAP 502 is transmitted again in the fifth superframe. At this time, the reverse switching is not performed in the second superframe but in the fifth superframe in which the MBS MAP is transmitted. That is, the switching sections are four superframes that are transmission periods of the MBS MAP. However, here, only 4 superframes are examples, and the switching period may be longer or shorter.

Due to the nature of the E-MBS service, one base station performs various services to a terminal, and a base station mainly transmits a signal and a terminal receives most of them. The terminal sometimes only transmits control signals to the base station. As described above, although the terminal often receives only from the base station, if the switching is performed every superframe, there may be a delay in service and the QoS may not be satisfied.

Since E-MBS service has a certain pattern for each MSI, it is more effective to perform carrier switching in accordance with the MSI cycle consisting of one or more superframes or the transmission cycle of MBS MAP instead of the superframe unit. It can also be solved. Here, FIG. 5 is only an example of the present invention, and the MSI cycle or the transmission cycle of the MBS MAP may be different from this, and the switching interval may also be changed accordingly.

The switching point or reverse switching point may be advanced or delayed. In addition, the switching period may be extended or shortened as the switching timing and the reverse switching timing are changed. E-MBS service often has a certain pattern for each MSI, and this pattern is mainly composed of superframe units. This is advantageous with fixed patterns, but not with varying patterns.

Figure 6 shows to advance or delay the reverse switching point in time according to the present invention.

Referring to FIG. 6, when reverse switching from the secondary carrier to the primary carrier, there is a case in which a situation in which data transmission is delayed or additional data needs to be transmitted, and thus, a period for transmitting a signal to the secondary carrier needs to be extended. This may be solved by delaying the reverse switching point (S610). On the contrary, even in the switching period, there may be times when the reverse switching to the primary carrier immediately for the transmission of uplink data, it can be solved by advancing the reverse switching (S620).

Figure 7 illustrates to advance or delay the switching time point in accordance with the present invention.

Referring to FIG. 7, there may be a case in which switching is not desired or a change point is pulled or slowed down. When switching from a secondary carrier to a primary carrier, the switching time itself is advanced (S710) or delayed. By switching (S720) it is possible to flexibly adjust the switching time. It may be an effective response when control information needs to be transmitted immediately on the primary carrier or when data transmission is delayed.

Hereinafter, a method of informing the information of the switching time point and the switching interval will be described.

8 shows an example of the base station to inform the switching information through the MBS MAP. In the MBS MAP 801, a superframe after 2 superframes is indicated as a switching time point. At the switching time point, switching from the primary carrier to the secondary carrier (S810), while staying in the secondary carrier during the switching period indicated by the MBS MAP, and reverse switching back to the primary carrier (S820). However, here, only two superframes after the switching time point is an example, and the switching time point and the switching interval may vary. The switching time point may be an offset value from the superframe including the MBS MAP, or may be a number of the superframe. Alternatively, it may be the start time of the MBS region of the data region of the superframe including the MBS MAP.

9 shows an example of informing switching information through an MBS MAP in a superframe. The MBH MAP 902 is indicated by the SFH 901 (S910), and the switching time point and the switching interval are indicated to the MBS region 903 of the data region through the MBS MAP (S920). After switching at the switching time point, data is transmitted during the switching period.

When control information such as a switching time point is included in the MBS MAP of the primary carrier, the UE can identify the MBS area indicated by the MBS MAP and switch to the secondary carrier using any point of the MBS area as the switching time point. have. In this case, the switching period may be a period from the switching time point to the end of the MBS region. When the switching period is finished, it may be reverse switching from the secondary carrier to the primary carrier.

The MBS MAP may include not only one switching time point and a switching period but also information of a next switching time point and a next switching period.

10 shows an example of a case where the MBS MAP includes information of a plurality of switching. The first switching (S1011) and reverse switching (S1012) can be performed by the instruction S1010 of the MBS MAP. If the MBS MAP also includes the next switching time point and the next switching period information, the terminal after the first switching is terminated, the primary carrier from the second carrier again during the next switching period from the next switching time point by the indication of the MBS MAP (S1020) A second switching may be performed (S1021), data may be transmitted or received during a period switched by the primary carrier, and reverse switching (S1022) may be performed after the end of the next switching interval.

On the other hand, switching can be applied to each content as well as MBS MAP. In this case, the MBS MAP defining the content may inform a time point, a period for receiving the content, and a time point for switching the carrier back to the primary carrier.

The switching point, switching interval and switching point from the secondary carrier to the primary carrier are not only MBS MAPs but also multi-carrier related messages, other MBS MAPs, subheaders, existing MAC management messages, new MAC management messages, or It may also be achieved through one or more combinations of control channels.

The above-described embodiments include examples of various aspects. While not all possible combinations may be described to represent the various aspects, one of ordinary skill in the art will recognize that other combinations are possible. Accordingly, the invention is intended to embrace all other replacements, modifications and variations that fall within the scope of the following claims.

Claims (15)

In a data transmission method by a base station in a multicast broadcast service (MBS) supporting multiple carriers in a wireless communication system,
Receiving a switching request message from the terminal indicating which E-MBS service the terminal requires;
Transmitting a switching response message including information on a switching time between a plurality of carriers set in the terminal to the terminal; And
And transmitting data regarding the E-MBS service requested by the terminal to the terminal through the primary carrier from the switching time point. The method of claim 1,
The switching request message includes an E-MBS connection bitmap, and each bit of the E-MBS connection bitmap is exclusively mapped to each of a plurality of E-MBS services to be switched by the terminal. Characterized in that, the data transmission method. The method of claim 1,
The switching response message includes a unicast available interval bitmap indicating whether unicast scheduling is available from the primary carrier to the terminal after switching to the primary carrier. Characterized in that it comprises a data transmission method. The method of claim 1,
And the switching time point can be advanced or delayed. The method of claim 1,
The switching request message or the switching response message further includes a switching interval which is a switching duration.
The switching period may be extended or shortened.
The method of claim 1,
And the switching response message is included in a MBS MAP. The method according to claim 6,
The switching time point is any one point of an MBS region of the MBS MAP,
The switching time point is determined by the base station. The method of claim 7, wherein
And reverse switching from the primary carrier to the secondary carrier at the end of the switching period. The method of claim 8,
If the MBS MAP includes information of a next switching time point and a next switching period, switching back from the secondary carrier to the primary carrier at the next switching time point with reference to the information; And
And receiving, by the terminal, data from the base station through the primary carrier during the next switching period. The method according to claim 6,
The switching time point is a time point at which transmission ends in an MBS region indicated by the MBS MAP of the secondary carrier,
If the MBS MAP indicates a next MBS MAP, switching from the secondary carrier to the primary carrier at the time when the next MBS MAP starts. The method according to claim 6,
If the MBS MAP further includes information of a next switching time point and a next switching period, switching from the secondary carrier to the primary carrier at the next switching time point with reference to the information; And
And receiving, by the terminal, data from the base station through the primary carrier during the next switching period. The method of claim 1,
The switching request message,
When the terminal requests the time to switch to the carrier after the DSA, DSC or DSD transaction (transaction) from the base station, without releasing the allocated E-MBS connection via the DSA-REQ or DSA-RSP message (release) When updating the indication on the E-MBS stream received by the UE at present or via the DSA-REQ or DSA-RSP message, the UE performs E-MBS carrier switching without releasing the allocated E-MBS connection. A method of transmitting data, characterized in that for transmitting when the time to stop (indicate). In a method for receiving data by a terminal in a multicast broadcast service (MBS) supporting multiple carriers in a wireless communication system,
Transmitting, to the base station, a switching request message indicating which E-MBS service is requested by the terminal;
Receiving a switching response message from the base station, the switching response message including information on a switching time between a plurality of carriers set in the terminal;
Switching from a secondary carrier to a primary carrier at the switching time point; And
And receiving data relating to an E-MBS service requested by the terminal from the base station through the primary carrier. The method of claim 13,
The switching request message includes an E-MBS connection bitmap, and each bit of the E-MBS connection bitmap is exclusively mapped to each of a plurality of E-MBS services to be switched by the terminal. Characterized in that the data receiving method. The method of claim 13,
The switching response message includes a unicast available interval bitmap indicating whether unicast scheduling from the primary carrier to the terminal is available after switching to the primary carrier. Characterized in that, the data receiving method.

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