KR100966179B1 - Method of receiving system information in the mobile communication system - Google Patents

Abstract

The present invention relates to a next generation mobile communication system, and more particularly, to a method for transmitting and receiving changed system information between a terminal and a base station to which a Radio Resource Control layer is connected. The present invention is in a connected state with a base station. If a mobile station is notified of the system information change and some contents of the system information from the base station through the already established dedicated control channel (DCCH), the downlink channel of the lower layer (PHY / MAC / RLC) is received to receive the changed system information. Set the shared channel (DBCCH: DL-SCH) to receive all the changed system information. The L1 parameter and the channel of the lower layer L1 / L2 layer are set again using the received information to continuously perform data communication and discontinuous reception.

Therefore, the present invention can recognize the change of the system information by using a dedicated control channel (DCCH) can shorten the delay time due to unnecessary channel setting, and can also reduce the power consumption by periodic channel demodulation. Will be.

Dedicated control channel, 3GPP, RRC.

Description

System information transmission and reception method of next generation mobile communication system {METHOD OF RECEIVING SYSTEM INFORMATION IN THE MOBILE COMMUNICATION SYSTEM}

The present invention relates to a next generation mobile communication system, and more particularly, to a method of transmitting and receiving changed system information between a terminal and a base station to which a Radio Resource Control layer is connected.

The present invention is derived from a study conducted as part of the IT growth engine technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development. [Task Management No.:2005-S-404-33, Project Name: 3G Evolution Handset Development]

3GPP, one of the next generation mobile communication systems, is expected to be highly competitive in the coming years through improvements in radio access technologies such as High Speed Packet Access (HSPA) data services (Release 6). However, 3GPP recognizes the necessity of a new mobile communication technology that provides various services of high quality while reducing the cost of users and operators compared to 3GPP R6 technology in order to efficiently provide rapidly developing information and communication services, and low transmission delay. The company is writing 3G Long Term Evolution (LTE) standard technology to improve low latency, high data rate, system capacity and coverage. Specifically, in terms of performance, it aims at 100 Mbps in the downlink and 50 Mbps in the uplink, and aims at 100 ms of call setup delay in the control plane and 5 ms in call processing delay in the data plane in terms of delay. I am doing it. It also aims to operate at various bandwidths, including 1.25, 2.5, 5, 10, 15 and 20 MHz, to support various spectrum allocations.

In the conventional R6 system, system information is transmitted through the mapping of BCCH: BCH (a logical channel of a broadcast control channel and a transport channel of a broadcast channel). There was a distinction between the master information (called the Master Information Block (MIB)) and the system information (called the System Information Block (SIB)) according to the contents included and the transmission period, but the channels through which the MIB and the SIB are transmitted are the same. In addition, the connection state of the radio resource control layer (RRC) is divided into CELL_DCH (dedicated data) state, CELL_FACH (common data) state, CELL_PCH (common radio call signaling) state, URA_PCH (common radio call signaling) state and the like. In the CELL_DCH state, the UE does not receive another channel because it communicates with only a dedicated channel (DCCH / DTCH) allocated thereto. In addition, all the specific information required for a specific UE is transmitted as a dedicated message through the DCCH.

However, since the UE in the CELL_DCH state communicates only with a dedicated channel, no change in system information has been transmitted. In the CELL_FACH, CELL_PCH, URA_PCH state, the UE must communicate on the shared channel (FACH / RACH, CELL_FACH) or wait for the paging channel (PCH, CELL_PCH / URA_PCH). Since the system information includes information on a common channel or a paging channel, the base station may notify the terminal when system information changes, such as a paging type 1 message or a system information change instruction (System Info.). Messages inform you of changes in system information. Upon receiving the paging type 1 or system info change message, the UE compares the tag included in the BCCH Modification Indication Information with the tag for the system information stored in the UE. When the system information is changed, the terminal sets L1 / L2 to receive a broadcast channel (BCH) and receives the system information. When reception of the changed system information is completed, it returns to the previous state and continues to communicate on the common channel (FACH / RACH, CELL_FACH), or waits for the paging channel (PCH, CELL_PCH / URA_PCH).

In the 3GPP LTE system, which is currently being standardized, system information includes: PBCCH (Primary Broadcast Channel) transmitting MIB: Broadcast Channel (BCH) channel mapping and DBCCH (Dynamic Broadcast Channel) transmitting SIB / SB (Scheduling Block): DL- It is divided into downlink shared channel (SCH) channel mapping. The RRC connection state is the same as the CELL_DCH state in the R6 system. The RRC connection state is a state in which a dedicated control channel (DCCH) is established and communication is performed using a dedicated data channel (DTCH), or a state in which communication can be performed. . However, in the LTE system, although it is said that system information is required for the connection state terminal to operate normally, it does not yet present a proper system information reception procedure. In order for the UE in the RRC connected state to recognize the system information change of the base station, it is necessary to check the system information change by receiving MIB transmitted periodically or continuously through the BCH. Since the connected UE basically sets up and uses downlink shared channel (DL-SCH) for data transmission / reception, in order to periodically receive a broadcast channel, data communication is interrupted temporarily and a broadcast channel is set to receive system information. It should be able to receive data and establish downlink shared channel again to perform data communication. In order to continuously receive the broadcast channel and check the system information change, two or more demodulators must be operated in the UE to receive broadcast channel information simultaneously with data communication. In order to perform the above operation, since the broadcast channel must be continuously demodulated, power consumption of the terminal may increase. In particular, when the UE includes two or more demodulators, the complexity of the UE may increase and the price may increase.

Accordingly, an object of the present invention is a method in which a terminal to which a Radio Resource Control layer is connected may receive changed system information from a base station in a short time in a next generation mobile communication system aiming at high transmission speed and low delay. And to provide a system information transmission method of the base station side to support the receiving method,

Furthermore, another object of the present invention is to provide a method for receiving system information of a terminal capable of reducing power consumption due to periodic broadcast channel demodulation, and a method for transmitting system information on a base station side required to support the method.

The present invention to achieve the above object is a method executable in the terminal of the next generation mobile communication system,

Receiving a dedicated paging message for being notified of a change in system information from a base station;

Establishing a lower layer channel necessary for receiving changed system information;

Receiving one or more system change information transmitted from the base station through the establishment channel;

Resetting parameters and channels of a lower layer by using the received system change information to perform data communication or performing a discontinuous reception procedure.

On the other hand, the system information transmission method of the base station for supporting the reception method,

Selecting a terminal to notify the fact of the change when the system information is changed;

Generating a dedicated paging message for notifying that the system information has been changed;

And transmitting the generated dedicated paging message to the selected terminal through the dedicated control channel.

According to the problem solving means of the above-described configuration, the mobile terminal (UE) of the present invention can be notified of the fact that the system information changes through the dedicated control channel that is already set up and waiting for reception from the base station connected to the radio resource layer Therefore, it is not necessary to set up a separate channel for receiving system information unnecessarily. Therefore, since there is no separate procedure for channel setting, system change information can be received more quickly, and power consumption due to periodic channel demodulation can be reduced.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Hereinafter, an embodiment of the present invention will be described assuming a 3GPP LTE system as an example of a next generation mobile communication system.

First, terms necessary for understanding the present invention will be described in detail. A message of a radio resource control layer for delivering system information in a 3GPP LTE system is called a system information block (SIB). The system information block (SIB) includes general system parameters, but includes a system information block (SIB) including the following specific information: a master information block (MIB), a broadcasting information block (SB), and the like. It is defined as

The master information block (MIB: hereinafter referred to as MIB) includes limited parameters that are transmitted very frequently, and the broadcast information block (SB: hereinafter referred to as SB) includes scheduling information on when other system information is transmitted. The MIB is transmitted in a fixed period through a broadcast channel (BCH), and the SB and SIB are transmitted in a fixed or dynamic period through a downlink shared channel (DL-SCH). MIB, SB, and SIB vary in size depending on the configured information, and since the size of the broadcast channel (BCH) and downlink shared channel (DL-SCH) for transmitting system information is fixed, MIB, SB and SIB is appropriately divided and transmitted according to the size, and the UE receives and recombines all of the divided MIB, SB and SIB. In order to receive a specific SIB using a dynamic period, the downlink shared channel (DL-SCH) is continuously received until all the divided SIBs are received, or the SIB is determined using the partitioning and transmission scheduling information of the specific SIB included in the SB. You should receive the split pieces of.

Referring to the configuration and operation of the present invention with reference to the above, first, Figure 1 is a UE connected to the radio resource control (Radio Resource Control: RRC) layer in the 3GPP LTE system according to an embodiment of the present invention (UE) ) Shows a flow diagram for receiving change system information (MIB / SIB), Figure 2 is a flow chart for determining a UE (UE) to notify the fact that the system information changes in Figure 1, and Figure 3 is an embodiment of the present invention Exemplary diagrams of structures of a dedicated paging message according to FIG.

Referring to FIG. 1, first, a UE 100 in an RRC connection performs communication with a base station (eNB) 110 using a data channel (DTCH) or a dedicated channel, or consumes power when there is no data to transmit. In order to reduce the power consumption, a discontinuous reception procedure (hereinafter, referred to as DRx) for waking up only for a specific time and checking data reception is performed (step 120).

If the base station-side system information is changed while the UE 100 performs the data communication or DRx reception procedure 120 (step 121), the base station 110 selects a UE to be notified of the change of the system information (step 122). . A method of selecting a UE to be notified of a change in system information by the base station 110 will be described with reference to FIG. 2.

First, when the system information is changed (step 201) due to a change in radio parameters, cell management, etc., the base station 110 examines which UE affects the changed information (step 202). Then, it is determined how quickly the changed information should be applied to the corresponding UE (steps 205 and 213), and finally the current operation state of the target UE is checked (steps 208 and 216).

If the changed information should be applied only to a specific UE (203) and the changed information should be applied immediately (206), as well as the operation of the corresponding UE (209) during high-speed communication, the RRC 111 of the base station 100 is a MIB. In operation S221, a dedicated paging message including both SIBs is generated and transmitted to the lower layer 112.

On the contrary, if the changed information is to be applied only to a specific UE (203) and the information that does not need quick application is changed (207), a dedicated paging message including MIB, SB, etc. is generated regardless of whether the UE is currently operated. In operation 212, the method transmits the information to the lower layer 112 (operation 221).

If the check result of step 202 changes the information for a plurality of terminals, whether the changed information should be applied immediately as in the case of a specific terminal (step 213), and further, what is the current state of the UE? Check (step 216) to generate a dedicated paging message (including MIB, SB) for a plurality of UEs according to the check result (step 219, 220). The generated message is delivered to the lower layer (step 221) to be delivered to the terminal.

That is, when the changed system information targets a specific UE, the base station 110 generates a dedicated paging message (step 211 and step 212), and then transmits a message using a dedicated control channel (DCCH) of the corresponding UE. Instruct the lower layer to 221 (221). If the changed system information corresponds to a plurality of (or all) UEs having a dedicated control channel instead of a specific UE target, the base station generates a dedicated paging message (steps 219 and 220) and then applies the corresponding paging message to all of the corresponding UEs. Instructing the lower layer to transmit to the dedicated control channel (step 221). As such, when transmitting a message to a plurality of terminals, a group-ID may be used in the PHY 114 layer.

For reference, the structure of the dedicated paging message generated by the base station 110 will be described in detail with reference to FIG. 3.

Dedicated paging message is “Message Type” Information Element (IE) to distinguish it from other messages transmitted through the dedicated control channel (DCCH), “Paging Cause” IE that describes the paging reason, minimum information frequency, MIMO status, system information “MIB Info” IE including Value Tag used as index, “SB Info” IE including number of segmented SIBs, repetition period, initial position and offset, cell information, timer / counter, wireless parameter, etc. “SIB # 1”, which contains category information,… , “SIB #n” IE, and the like.

Among them, “Message Type”, “Paging Cause” and “MIB Info” IE must be included in the dedicated paging message (MP, Mandatory Present parameter). The “SB Info” IE may not be included when the terminal needs to receive all SIBs (OP, Optional parameter), and includes scheduling information of the corresponding SIB when only the specific SIB is to be received. In addition, “SIB # 1”,... In this case, the “SIB #n” IE may be changed when the system information to be received is small or the parameter needs to be quickly transmitted during data communication. When the SIB to be received is included in the message, in FIG. 1, the UE may receive all necessary information in step 131, thereby omitting steps 136, 139, 140, 141, and 142.

As described above, when the UE for notifying the system information change fact is selected in the RRC layer 111 of the base station 110, the base station 110 generates a dedicated paging message to be transmitted to the selected UE as described above. (Step 123). The generated message includes the paging reason, the changed MIB information, the scheduling information (SB) for the location of the changed specific SIB that the specific terminal 100 should receive, or the changed system information (SIB) itself that the UE should receive. May be included. What content is included in the dedicated paging message may vary depending on the type of system information included, the message length, and the destination of the message (one or more UEs).

The RRC 111 layer requests the transmission of the generated message data to the RLC layer 112 (step 124), which is transmitted to the UE via the MAC 113 layer and the PHY 114 layer (steps 125 and 126). ). In this case, the logical channel is transmitted in the message using a dedicated control channel (DCCH) and the transport channel is transmitted using a downlink shared channel (DL-SCH) (step 127).

Meanwhile, the PHY layer 104 of the UE continuously or periodically wakes up and receives the message through the dedicated control channel (DCCH), which is waiting to receive the message to the MAC layer 103 (step 128), and the MAC layer 103. The message transmitted to the RRC layer 102 is again passed through the RLC layer 102 (step 129) to the RRC layer 101 (step 130).

The RRC layer 101 of the UE 100 receiving the dedicated paging message on the dedicated control channel (DCCH) checks the change of the system information through the paging reason information, and types of system information to be received using the included information. The position of the PHY / MAC / RLC layer is set to a downlink shared channel (DL-SCH: DBCCH) to receive the changed system information (step 136). If the SIB is included in the dedicated paging message, the process proceeds to step 143 without setting a broadcast channel.

On the other hand, the base station 110 is divided into one or more through the MIB (132, 134, 137) and DBCCH: DL-SCH divided into one or more through the broadcast channel (PBCCH: BCH) through the internal procedure after the system information is changed The various SIBs (steps 133, 135, and 138) are periodically transmitted. In the UE 100, when the setting of the lower layer for receiving the system information (SIB) is completed (step 136), the PHY layer 104 receives the SIB through the configured DBCCH: DL-SCH (step 138). The received data is transferred to the RRC layer 101 via the MAC 103 and the RLC layer 102 (steps 139 and 140) (step 141). When the RRC layer 101 repeats the above-described steps (138, 139, 140, and 141) to receive all the desired system information (SIB) (step 142), the RRC layer 101 uses the received information to determine the L1 / L2 layer. The parameter and the channel are set (step 143). Thereafter, the UE 100 continues the procedure 120 performed before the change of the system information, that is, the data communication / DRx operation (step 144).

According to the above embodiment, when the terminal, which is connected to the base station, is notified of the system information change from the base station through the already established dedicated control channel (DCCH), the lower layer (PHY / MAC / RLC) is set as a downlink shared channel (DBCCH: DL-SCH) to receive all changed system information. The L1 parameter and the channel of the L1 / L2 layer, which is the lower layer, are set again using the received information to continue data communication and DRx operation.

Therefore, the present invention can recognize the change of the system information by using a dedicated control channel (DCCH) can shorten the delay time due to unnecessary channel setting, and can also reduce the power consumption by periodic channel demodulation. Will be.

On the other hand, the present invention has been described with reference to the embodiments shown in the drawings, which are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the true scope of the present invention should be determined only by the appended claims.

1 is a flow diagram of receiving change system information (MIB / SIB) of a radio resource control (RRC) connected state terminal (UE) in a 3GPP LTE system according to an embodiment of the present invention.

FIG. 2 is a flowchart for determining a UE for notifying change of system information in FIG. 1; FIG.

3 is an exemplary structure diagram of a dedicated paging message according to an embodiment of the present invention.

Claims (10)

In the method for receiving system information executable in the mobile communication terminal, Receiving a dedicated paging message for being notified of a change in system information from a base station; Establishing a lower layer channel necessary for receiving changed system information; Receiving one or more changed system information transmitted from the base station through the established channel; And performing data communication or discontinuous reception by resetting the parameters and channels of the lower layer by using the received changed system information. The method as claimed in claim 1, wherein the dedicated paging message is received through a dedicated control channel. The method according to claim 1 or 2, wherein the lower layer is a lower layer of a radio resource control layer. The method of claim 1 or 2, wherein the dedicated paging message is at least: Message type information for distinguishing from other messages transmitted through a dedicated control channel; Information for explaining the reason for paging; And And master information block information (MIB Info) including value tag information used as a system information index. In the system information transmission method executable in the base station of the mobile communication system, Selecting a terminal to notify the fact of the change when the system information is changed; Generating a dedicated paging message for notifying that the system information has been changed; And transmitting the generated dedicated paging message to the selected terminal through a dedicated control channel. The method of claim 5, A base station of a mobile communication system, characterized by generating a dedicated paging message limited to a specific terminal according to the number of selected terminals and application time of changed system information, wherein the generated dedicated paging message includes a master information block and a system information block. How to send system information executable on. The method of claim 5, Generate a dedicated paging message specific to a specific terminal according to the number of the selected terminal and the application time of the changed system information, wherein the generated dedicated paging message includes a scheduling information block and a master information block for transmission of the changed system information. A system information transmission method executable in a base station of a mobile communication system. The method of claim 5, A base station of a mobile communication system, characterized by generating a dedicated paging message for a plurality of terminals according to the number of selected terminals and the application time of changed system information, wherein the generated dedicated paging message includes a master information block and a system information block. How to send system information executable on. The method of claim 5, Generate a dedicated paging message for a plurality of terminals according to the number of the selected terminal and the application time of the changed system information, wherein the generated dedicated paging message includes a scheduling information block and a master information block for the transmission of the changed system information A system information transmission method executable in a base station of a mobile communication system. 10. The method of any of claims 5-9, wherein the dedicated paging message is at least: Message type information for distinguishing from other messages transmitted through a dedicated control channel; Information for explaining the reason for paging; And And master information block information (MIB Info) including value tag information used as a system information index.

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