Specification MOBILE COMMUNICATIONS SYSTEM, BASE STATION, AND MOBILE TERMINAL Field of the Invention [0001] The present invention relates to a mobile communications system that can notify emergency information by using a broadcast type multimedia service, and a base station and a mobile terminal which construct this mobile communications system. Background of the Invention [0002] Recent years have seen growing social needs for a system which, in the event of occurrence of an emergency situation, such as an earthquake or a tsunami, can notify emergency information about the emergency to many people immediately. On the other hand, the market size of mobile terminals, such as mobile phones, is increasing year by year. In Japan, the market size has reached more than 90 million sets of mobile terminals and there occur social circumstances in which many persons own a mobile phone. Therefore, information delivery using mobile terminals via a mobile communications network can be made to serve as an effective notifying means of notifying emergency information. [0003] As a system for notifying emergency information, for example, J-ALERTT nationwide inetantaneo»#-ftT(&ft system) has been examined. This nationwide instantaneous alert System is assumed to use a municipal disaster prevention radio to notify «nergency information by way of speakers for disaster broadcasting which are mainly installed indoors and outdoors. However, this nationwide instantaneous alert system using speakers to notify, by voice, emergency information causes a case in which those who live in an area distant- from the speakers and so on cannot know the emergency information. [0004] - To solve this problem, there has been proposed a system that notifies, by voice or by using an e-mail, emergency information to mobile terminals, which users who are registered to receive a service manage respectively, via an existing mobile communications network. Furthermore, there has been also considered a method of broadcasting emergency information to an indefinite number of users by using digital terrestrial broadcasting. [0005] As a service for broadcasting information to an indefinite number of users in a mobile communications system, there has been provided, for example, a CBS (Cell Broadcast Short message service) (refer to nonpatent reference 1) .. This CBS is a point-to-multipoint (Point to Multipoint) service which enables a base station which provides a service in a mobile communications system to carry out broadcast communications with mobile tei-minals which are registered into the base station and have come under the control of the base station.„ It is defined according to the 3GPP (3 rd Generation Partnership Project) that each mobile terminal can be placed in either one of the following states: an Idle state, a CELL_DCH state, a CELL_FACH state, a CELL_PCH state,' and a URA_PCH state (refer to nonpatent reference 2) . In the mobile communications system, each mobile terminal operates while making a transition among I these states whenever necessary. [0006] Furthermore, as a conventional emergency information notifying system using a mobile communications network, for example, patent reference 1 discloses an emergency information notifying system. This emergency information notifying system uses broadcast information which a base station transmits to all the mobile terminals being -uider the control thereof for notification of emergency information. The emergency information notifying system adds, as parameters, channel information used for reception of the emergency information and an identifier of the emergency information to this broadcast information, so that all the mobile terminals can receive a channel via which the emergency information is transmitted thereto on the basis of these parameters. [0007] On the other hand, as a service suitable for transmitting emergency information to an indefinite number of user terminals in a mobile communications system, a broadcast type multimedia service which enables simultaneous delivery of one transmission data to a plurality of users ' mobile terminals has been studied. In this broadcast type multimedia service, especially, multimedia information about spqrts live broadcasting, a weather forecast, a radio, j.ojr- the like is delivered simultaneously to a plurality of,users' mobile terminals as a service of the mobile communications system. In the 3GPP, this technology is called an MBMS (Multimedia Broadcast Multicast Service) (refer to nonpatent reference 3). [0008] In the MBMS, it is assumed that a multimedia service as mentioned above is provided, and a fast transfer of a moving image or the like is supported. Therefore, as compared with the CBS, a larger amount of information can be transmitted at a higher rate, and the MBMS is suitable for a system for broadcasting emergency information according to the needs of, an indefinite number of users. [0009] As channels in a wireless section used for the MBMS, as shown in nonpatent reference 3, three logical channels (anMCCH, anMTCH, andanMSCH) are introduced, and an MICH (MBMS Indicator CHannel) is introduced as an indicator similar to a PICH. The MCCH (MBMS Control CHannel) is a channel on which control information about the MBMS is carried, and the MTCH (MBMS Traffic CHannel) is a channel on which data about the MBMS are carried. The MICH has the same physical structure as the PICH based on the R99 (release 99) standard in the 3GPP, and, when information is carried on the MCCH, this bit is set in advance. [0010] A mobile terminal receives data about the MBMS which are carried on the MTCH according to the MBMS control channel (MCCH) . When certain information is carried on the MCCH, the bit of the MICH which is an indicator for MBMS notification is set, and, after recognizing the bit, the mobile terminal receives the MCCH- on which new control information is carried. In this case, the ..". mobile terminal receives the MTCH on which data about the MBMS.- are carried according to .the newly received MCCH. '' [0011] Furthermore, the procedure for receiving the MCCH does not depend on the state in which the mobile terminal can enter (the Idle state, and the RRC connected state (RRC_Connected) (the CELL DCH state, the CELL FACH state, the CELL PCH state, or the URA_PCH state) ) , and can be applied to all mobile terminals which support the MBMS (refer to nonpatent reference 4) . Therefore, even if a mobile terminal is placed in any of the above-mentioned states, the mobile terminal can receive data about the MBMS. [0012] According to the 3GPP, as a communications method different from W-CDMA, a new communications method which is called "long term evolution" (Long Term Evolution LTE) for a wireless section and which is also called "system architecture evolution" (System Architecture Evolution SAE) for a whole system structure including a core network has been examined. In an access method for LTE, OFDM (Orthogonal Frequency Division Multiplexing) is used for a downlink direction, while SC-FDMA (Single Career Frequency Division Multiple Access) is used for an uplink direction. The bandwidth in the case of W-CDMA is 5 MHz, while the bandwidth in the case of LTE can be selected from among 1.4MH2, 3MHz, 5MHz, lOMHz, 15MHz, and 20MHz for each and every base station. Furthermore, in the case of LTE, no circuit switching is included, unlike in the case of W-CDMA, only a packet communications method is included. [0013] In an LTE communications system,, .a-base station (Base station) that communi<;ates with a mobile terminal (UE: User Equipment) is called an. eNB (E-UTRAN NodeBh, and a base station control apparatus (Radio Network Controller) which performs exchange of control data and user data with a plurality of base stations is called an EPC (Evolved Packet Core) (also called an aGW: Access Gateway) . In this LTE communications system, a unicast (Unicast) service and an E-MBMS service (Evolved Multimedia Broadcast Multicast Service) are provided. The E-MBMS service is a broadcast type multimedia service, and may ; be simply called an MEMS. A large-amount broadcast content, such as a news content, a weather forecast content, -or a mobile broadcasting content, is transmitted to a plurality of mobile terminals. This is also called a point-to-multipoint (Point to Multipoint) service. [0014] The current determined matters of the whole architecture (Architecture) of LTE systeos in the 3GPP are described in nonpatent reference 5. The whole architecture will be explained with reference to Fig. 11 (refer to Chapter 4 of nonpatent reference 5). Fig. 11 is an explanatory drawing showing the structure of a communications system according to an LTE method. In Fig. 11, if a control protocol (e.g. RRC (Radio Resource Management) ) and a user plane (e.g. PDCP: Packet Data Convergence Protocol, RLC: Radio Link Control, MAC: Medium Access Control, PHY: Physical layer) for a mobile terminal 101 are terminated at a base station 102, an E-UTRAN (Evolved Universal Terrestrial Radio Access) is constructed of one or more base stations 102. Each base station 102 carries out scheduling (Scheduling) and transmission of a paging signal (Paging Signaling'which is also called a paging message (paging •' message)) which-is notified from an MME (Mobility-Management ■ Entity) 103 . The b'&se stations 102 are connected to one another via an X2 interface. Furthermore, each base station 102 is connected to an EPC (Evolved Packet Core) via an SI interface. More specifically, each base station 102 is connected to an MME (Mobility Management Entity) 103 via an S1_MME interface, and is connected to an S-GW (Serving Gateway) 104 via an S1_U' interface. Each MME 103 distributes a paging signal to a-plurality of base stations 102 or a single base station 102. Furthermore, each MME 103 performs mobility control (Mobility control) in an idle state (Idle State) . Each S-GW 1.04 performs transmission and reception of user data to and from one or more base stations 102., [0015] The current determined matters about the frame structure of LTE systems in the 3GPP are described in nonpatent reference 5 (Chapter 5) . They will be explained with reference to Fig. 12. Fig. 12 is an explanatory drawing showing the structure of a radio frame for use in a communications system using an LTE method. In Fig. 12, one radio frame (Radio frame) has a length of 10ms. The radio frame is divided into ten equal-sized sub-frames (Sub-frames). Each of the sub-frames is divided into two equal-sized slots (slots). A downlink synchronous channel (Downlink Synchronization Channel: SCH) is included in each of the first (#0) and sixth (#5) sub-frames of every frame. Synchronizing signals include a primary synchronization channel (Primary Synchronization Channel: P-SCH) and a secondary synchronization channel (Secondary Synchronization Channel: S-SCH)-. Multiplexing of channels for MBSFN (Multimedia Broadcast multicast seirvice Single Frequency Network) and channels other than the channels for MBSFN is performed on a sub-frame basis. Hereafter, sub-frames for MBSFN transmission are called MBSFN sub-frames (MBSFN sub-frames) . In nonpatent references, an example of signaling at the time of assignment of MBSFN sub-frames is described. Fig. 13 is an explanatory drawing showing the structure of MBSFN frames. As shown in Fig. 13, MBSFN sub-frames are assigned to every MBSFN frame (MBSFN frame). MBSFN frame clusters (MBSFN frame Clusters) are scheduled. The repetition period (Repetition Period) of the MBSFN frame clusters is assigned. [0016] The current determined matters about the channel configuration of LTE systems in the 3GPP are described in nonpatent reference 5. Physical channels (Physical channels) will be expflained with reference to Fig. 14 (refer to Chapter 5 of nonpatent reference 5) . Fig. 14 is an explanatory drawing explaining physical channels for use in a communications system according to an LTE method. In Fig. 14, a physical broadcast channel 401 (Physical Broadcast channel: PBCH) is a downlink channel which is transmitted from a base station 102 to a mobile terminal 101. BCH transport blocks (transport blocks) are mapped to four sub-frames during an interval of 40ms. There is no clear signaling at a timing of 40ms. A physical control channel format indicator channel 4 02 (Physical Control format indicator channel: PCFICH) is transmitted from the base station 102 to the mobile terminal 101. The PCFICH is used to notify the number of OFDM symbols which are used for PDCCHs from the base station 102 to the mobile terminal 101. The PCFICH is transmitted for every sub-frame. A physical downlink control channel 403 (Physical downlink control channel-: PDCCH) is a downlink channel which is transmitted from thebase station 102 to the mobile terminal 101. The PDCCH is used to notify resource allocation (allocation), HARQ information about a DL-SCH (a downlink shared channel which is one of transport channels shown in Fig. 15), and a PCH (a paging channel which is one of the transport channels shown in Fig. 15) . The PDCCH carries an uplink scheduling grant (Uplink Scheduling GrantT".'' The PDCCH carries ACK/Nack which is a response signal to uplink transmission. A physical downlink shared channel 4 04 (Physical downlink shared channel: PDSCH) is a downlink channel which is transmitted from the base station 102 to the mobile terminal 101. A DL-SCH (a downlink shared channel) which is a transport channel is mapped- to the PDSCH. A physical multicast channel 405 (Physical multicast channel: PMCH) is a downlink channel which is transmitted from the base station 102 to the mobile terminal 101. An MCH (multicast channel) which is a transport channel is mapped to the PMCH. [0017] A physical uplink control channel 4 06 (Physical Uplink control channel: PUCCH) is an uplink channel which is transmitted from the mobile terminal 101 to the base station 102. The PUCCH carries ACK/Nack which is a response signal (response) to downlink transmission. The PUCCH carries a CQI (Channel Quality indicator) report. CQI is quality information showing either the quality of received data or channel quality. A physical uplink shared channel 407 (Physical Uplink shared channel: PUSCH) is an uplink channel which is transmitted to the base station 102 from the mobile terminal 101-. A UL-SCH (uplink-shared channel which is one of the transport channels shown in.Fi-g. 15) is mapped to the PUSCH." A physical HARQ indicator channel 4 08 (Physical Hybrid ARQ indicator channel: PHICH) is a" downlink channel which is transmitted from the base station 102 to the mobile terminal 101. The PHICH carries ACK/Nack which is a response to uplink transmission. A physical random access channel 409 (Physical random access channel: PRACH) is an uplink channel which is transmitted from the mobile terminal 101 to the base station 102 , The PRACH carries a random access preamble (random access preamble). [0018] The transport channels (Transport channels) will be explained"with reference to Fig. 15 (refer to Chapter 5 of nonpatent reference 5). Fig. 15 is an explanatory drawing explaining the transport channels for use in a communications system according to an LTE method. Mapping between the downlink transport channels and the downlink physical channels is shown in Fig. ISA. Mapping between the uplink transport channels and the uplink physical channels is shown in Fig. 15B. As to the downlink transport channels, a broadcast channel (Broadcast channel: BCH) is broadcast to all the base stations (cell) . The BCH is mapped to the physical broadcast channel (PBCH). Retransmission control with HARQ (Hybrid ARQ) is applied to the downlink shared channel (Downlink Shared channel: DL-SCH). A broadcast to all the base stations (cell) can be carried out. Dynamic or semi-static (Semi-static) resource allocation is supported. Semi-static resource allocation is also referred to as persistent scheduling (Persistent Scheduling) . In order to decrease the power consumption of a mobile terminal, DRX (Discontinuous reception) of the mobile terminal is supported. The Dir-SCH is mapped to the physical downlink shared channel' (PDSCH)"'. The paging channel (Paging channel: PCH) supports the" DRX of tiie mobile terminal in order to enable decrease in thfe* power consumption of the mobile terminal. A request for a broadcast to all the base stations (cell) is made. It is mapped to either a physical resource like the physical downlink shared channel (PDSCH) which can be dynamically used for traffic, or a physical resource like the physical downlink control channel (PDCCH) which is another control channel. The multicast channel (Multicast channel: MCH) is used for a broadcast to all the base stations (cell) . SPif tSWiBTning of MBMS services (the MTCH and the MCCH) in multi-cell transmission is supported. Semi-static resource allocation is supported. The MCH is mapped to the PMCH. [0019] Retransmission control with HARQ (Hybrid ARQ) is applied to the uplink shared channel (Uplink Shared channel; UL-SCH) . Dynamic or semi-static (Semi-static) resource allocation is supported. The UL-SCH is mapped to the physical uplink shared channel (PUSCH). A random access channel (Random access channel: RACH) shown in Fig. 15B is limited to control information. There is a risk of collision. The RACH is mapped to the physical random access channel (PRACH). [0020] The logical channels (Logical channels) will be explained with reference to Fig. 16 (refer to Chapter 6 of nonpatent reference 5) . Fig. 16 is an explanatory drawing explaining the logical channels for use in a communications system according to an LTE method. Mapping between the downlink logical channels and the downlink transport channels, is shown in Fig. 16A. Mapping between the uplink logical channels and the uplink transport channelsis shown in Fig. 16JB; A broadcast control channel (Broa signal processing,- such as de-spreading and phase correction, The combining unife 22 inputs the signals processed by the finger units 21 and performs rake combining on the signals. [0062] The code generator 23 generates the channelization code and the scrambling code which are used for the demodulation process of demodulating the received signals which is carried out by-the receiving units 20a to 20c according to control by the control unit TS, and outputs the channelization code and the scrambling code to the receiving units 20a to 20c. According to the control by the control unit 33, the search unit 24 performs a cell search andmultipath detection on the digital signal to which the analog baseband signal is converted by the A/D converter 19, and outputs the detected results to each of the receiving units 20a to 20c. The finger assignment control unit 25 assigns the path of a channel via which a signal is to be received to each finger unit 21. [0063] The input memory 26 stores the signal which is rake-combined by the combining unit 22 of each of the receiving units 20a to 20c therein. The decoding unit 27 performs decoding processing, such as a CRC check and turbo decoding, on data read from the input memory 26. The output memory 28 stores the data on which decoding processing is performed by the decoding unit 2 7 therein. The memories 26 and 28 can be memories independently disposed for each of the receiving units. As an alternative, the receiving units 2 0a to 20c can share a single large memory. [0064] ■ - - - ■' The broadicTast information -receiving unit 29 reads required broadcast information from BCH decoded data stored in the output memory 28, and outputs the required broadcast information to the protocol processing unit 8. Each of the downlink dedicated channel receiving unit 3 0 and the downlink shared channel receiving unit 31 outputs decoded application data read from the output memory 28 to the application processing unit 7, and also- outputs data which are decoded control information to the protocol processing unit 8. The selecting unit 32 outputs the decoded data read from the output memory 28 to the downlink shared channel receiving unit 31 according to the control by the control unit 33. The control unit 33 controls the processes carried out by the above-mentioned components 7 to 32. That is, only a part of all signal wires from the control unit 33 to the components is shown in Fig. 3, and the control unit 33 also controls the processes carried out by components for which no signal wires are shown in the figure. [0065] Hereafter, a process of receiving data from a base station 2 which is carried out by each mobile terminal 1 will be explained. A weak signal received by the antenna 16 is amplified by the low noise amplifying unit 17, and is converted into a baseband signal by the frequency converting unit 14 . The A/D converter 19 converts the analog baseband signal into a digital signal, and outputs the digital signal to the receiving units 2 0a to 2 0c and the search unit 24 . The search unit 24 identifies the scrambling code of the base station-2.from the inputted digital signal, informs the scrambling CQde-to the control unit 33, and also detects the path timing from,-this digital signal and then informs the detected timing to the-receiving units 20a to 2 0c and the finger as»ig«M»ent control unit 25. Furthermore, on the basis of information about the cell specified by the search unit 24, the control unit 33 provides an instruction showing which channel of which cell should be received for each of the receiving »Mritp*iJ-irt«l:>aiil>*''-' - [0066] The finger assignment control unit 33 selects a path which .•'is assumed to be effective from among a plurality of,,paths on .-the basis of the search results obtained by the search unit 24, and assigns the selected path to each finger unit 21. According to the control by the control unit 33, the code generator 23 generates the scrambling code corresponding to the base stations 2 of each cell from which the mobile terminal is going to receive signals, and the channelization code of the channel via which the mobile terminal is going to receive signals, and outputs the scrambling code and the channelization code to the receiving units 2 0a to 20c. [0067] The control unit 33 determines whether to perform selective combining by, for example, comparing at least one of the channel quality information (CQI information) about the uplink/downlink channels in the decoding unit 27, the frequency of occurrence of CRC (Cyclic Redundancy Check) errors, and received power, such as a signal-power-to-interference-received-power ratio, with a given threshold. When performing selective combining, the control unit 33 controls the code generator 23 in such a way •that the receiving anits 2Da to 20c receive S-CCPCHs for the ••MBMS from different'base stations 2, respectively.,;' [0068] v As shown in Fig. 3, each mobile terminal 1 has the three receiving units 2 0a to 2 0c, and, for example, the receiving unit 20a receives an S-CCPCH for control information and the receiving unit 20b receives an S-CCPCH for the MBMS. Furthermore, the receiving unit 2Ocf receives an S-CCPCH for the MBMS from another base station 2 for selective combining. The receiving units 20a to 20c can receive signals on these channels at independent timings, respectively. [0069] The finger units 21 of each of the receiving units 2 0a to 2 0c receive the signals of their respective paths assigned thereto by the finger assignment control unit 2 5 on the. basis -Of the codes inputted thereto from the code generator 23, and performs signal processing, such as de-spreading and phase correction, on the signals, and outputs thase signals processed thereby to the combining unit 22 . The combining unit 22 inputs the signals processed by the finger unit 21, and carries out rake combining of the signals to generate and store a rake-combined signal in the input memory 26. [0070] The decoding unit 27 reads the received data processed by the receiving units 20a to 20c from the input memory 26, performs decoding processing, such as data CRC and turbo decoding, on the received data, and writes the decoded results in the output memory 28. In general, because the hardware of a decoder has a large circuit scale, the single unit is time-shared in many cases. However, in a case in which a plurality of decoders are mounted, a decoder can be assigned tb;each and every cell or each and--every channel. -\-- ' [0071] After that, a required process is carried out for each aadvary channel, the broadcast information receiving unit 2 9 acquires required broadcast information from the BCH, and delivers the required broadcast information to the protocol processing unit 8 . When the decoded data are application data. the downlink dedicated channel receiving unit 3 0 sends the data to the application processing unit 7, whereas when the decoded data are control information, the downlink dedicated channel receiving unit sends the data to the protocol processing unit 8. " [0072] r When carrying out the selective combining, the selecting unit 32 reads the two sets of data on the S-CCPCHs for the MBMS, which the receiving units 20b and 20c have received from the different base stations 2, from the output memory 28, and outputs the set of read data which the selecting unit 32 assumes to be correct on the basis of the CRC results or the like obtained by the decoding unit 27 to the downlink shared channel receiving unit 31, and discards the other set of read data. [0073] In contrast, when not performing the selective combining, the selecting unit 32 outputs the two sets of data which the receiving units 20b and 20c have received to the downlink shared channel receiving unit 31 without discarding them. When the received data are application data, the downlink shared channel receiving unit 31 sends the data to the application processing unit 7, whereas when the received data are control information, the downlink shared channel receiving unit sends the data to the protocol-'|)rocessing unit 8, like the downlink dedicated channel receiving unit 30. "" [0074] As mentioned above, the S-CCPCH received by each of the receiving units 20a to 20c includes S-CCPCH system information (Secondary CCPCH system information) and S-CCPCH information (Secondary CCPCH information) , and each mobile terminal 1 can acquire information required for demodulation of the spreading factor about the S-CCPCH, the channelization code, the timing offset, etc. from these pieces of information. These parameters are received, as control information, by either one of the broadcast information receiving unit 29, the downlink dedicated channel receiving unit 30, and the downlink shared-channel receiving unit 31, and are stored and managed by the protocol processing unit 8 . The protocol processing unit 8 sets the above-mentioned parameters to the receiving units 2 0a to 20c, the code generator 23, the search unit 24, and the finger assignment control unit 25. [0075] In order to receive an S-CCPCH for control information only from one active cell, each mobile terminal 1 does not combine signals from different cells. At this time, the finger assignment control unit 2 5 assigns only a multipath component from one cell to each finger unit 21. The control unit 33 also observes signals (electric waves) from the base stations 2 from which the receiving units 20a to 20c have received the S-CCPCH signals, and transmits transmission power control information used for making a request to increase or decrease the transmission power to the protocol processing unit 8 according, to the"observation results. The protocol processing unit .8"' transmits the transmission power control.information inputted from the control unit 33 to the base stations 2 by using the uplink shared channel transmitting unit 9 or the uplink dedicated channel transmitting unit 10. [0076] Next, each base station (Node-B) which constructs the mobile communications system in accordance with the present invention will be explained. Fig. 4 is,a diagram showing the structure of each base station shown in Fig. 1. As shown in Fig. 4, in addition to an antenna 42, each base station 2 is provided with, as components for transmitting data to a mobile terminal l, a broadcast information transmitting unit 34, a downlink; dedicated channel transmitting unit 35, a downlink shared channel transmitting unit 36, a modulating unit 37, a downlink code generator 38, a D/A converter 39, a frequency-converting unit 40, and a power-amplifyinGunit 41. Each base station 2 is further provided with, as components for receiving a signal from a mobile terminal 1, a low noise amplifying unit 43, a frequency converting unit 44, an A/D converter 45, a demodulating unit 46, an uplink code generator 47, an uplink dedicated channel receiving unit 48, and an uplink shared channel receiving unit 49. [0077] The broadcast information transmitting unit 34 receives broadcast information to be transmitted to a mobile terminal 1 via a base station control apparatus 3, and carries out a coding process of coding the broadcast information to generate data to be carried on the P-CCPCH. The downlink dedicated channel transmitting" unit 35 is disposed for each and every mobile terminal 1-using a dedicated-channel, and receives data or control inf oitaation on the dedio'a:ted channel via a base station control apparatus 3 and then carries out a coding process of coding the data or control information to generate data -tobe-carried on the DPCH. ■'vnrthermore, the downlink shared channel transwittingunit 36 receives control information or multimedia data via a base station control apparatus 3, and carries out a coding process of coding the control information or multimedia data to generate data to be carried on the S-CCPCH. In each base station 2, one or more S-CCPCHs can be provided. [0078] In accordance with the present invention, an emergency information flag indicating the presence or absence of emergency information is newly-:, disposed in the .MCCH to be transmitted via the S~CCPCH. When receiving multimedia data which are emergency information via a base station control apparatus 3, the downlink shared channel transmitting unit 36 sets a digital value showing "presence" to the emergency information flag included in the MCCH. For example, in a case in which 1 bit of digital data is set up as the emergency information flag, a digital value of 1 shows the presence of emergency information while a digital value of 0 shows the absence of emergency information. [0079] The modulating unit 37 accepts the data coded by the transmitting units 34 to 36, and performs a spreading process on the data on each and every channel by using the channelization code and the scrambling code which are set up by the downlink code generator 38. The D/A converter 39 converts the digital data on which the spreading process is performed by the jnodulating unit 37 into an -analog signal. The., "frequency converting unit 4 0 converts th€ analog signal to which the digitml data are converted by the D/A converter 3 9 into an RF signal. The power amplifying unit 41 amplifies the electric power of the RF signal to which the analog signal is converted by the frequency converting unit 40 . The power amplifying unit 41 controls its amplification degree on the basis of the txanamission power control information received from the mobile terminal 1. The antenna 42 transmits, as a radio signal, the signal amplified by the power amplifying unit 41, and also receives asignal from a mobile terminal 1. [0080] The low noise amplifying unit 43 amplifies the weak signal power received from the mobile terminal 1 via the antenna 42 . The frequency converting unit 44 converts the signal amplified by the low noise amplifying unit 4 3 into a baseband signal. The A/D converter 45 converts the analog baseband signal inputted thereto from the frequency converting unit 44 into a digital signal. The demodulating unit 46 demultiplexes the digital signal into data from the mobile terminal 1 by using the scrambling code set up by the uplink code generator 47, and deaai-ltipiexes the data into data on each channel of this mobile terminal 1 by using the channelization code. The uplink dedicated channel receiving unit 48 carries out channel decoding of the signal on the dedicated channel which is demodulated by the demodulating unit 46 to demultiplex, and transmits the signal of the dedicated channel to a base station control apparatus 3 . The uplink shared channel receiving unit 4 9 carries out channel decoding of the signal of the shared channel which is demodulated by the demodulating unit 46 to 3. [0081}: «te« Next, a data transmission process of transmitting data to a mobile terminal 1 which is carried out by each base station 2 will be explained. Varioua piiaces of control information or data to be transmitted to a mobile terminal 1 are received via a base demultiplex,-ancl transmits to a base station control apparatus station control apparatus 3, and are sent to the transmitting units 34 to 3 6 which transmit control information or data about channels associated therewith, respectively. Broadcast information on which a coding process is performed as data on the P-CCPCH is sent to the modulating unit 37 by the broadcast information transmitting unit 34, control information or data on which a coding process is performed as data on the DPCH are sent to the modulating unit 3 7 by the downlink dedicated channel transmitting unit 35, and control information or multimedia data on which a coding process is performed as data on the S - CCPCH are sent to the modulating unit 3 7 by the downlink shared channel transmitting unit 36. The modulating unit 37 carries out a spreading process of the data, which are inputted from either one or more of the transmitting units 34 to 36, for each and every channel by using the channelization code and the scrambling code which are inputted from the downlink code generator 38, and then outputs the spread data to the D/A converter 39. The D/A converter 39 converts the digital signal inputted from the modulating unit 37 into an analog signal, and the frequency converting unit 4 0 further converts the analog signal to which the digital signal is converted by the D/A converter 39 into an RF signal. This RF signal is amplified so as to have desired electric power by the. power amplifying unit 41, and is transmitted, as a radio signal, to the mobile terminal 1 via the antenna 42. Next, a data receiving process of receiving data from a mobile terminal 1 which is carried out by each base station 2 will be explained. A weak signal from mobile terminals 1 received via the antenna 42 is amplified by the low noise amplifying unit 43. The frequency converting unit 44 converts the signal amplified by the low noise'amplifying unit 43 into a baseband signal, and the A/D converter 45 converts the baseband signal into a digital signal. The demodulating unit 46 demultiplexes the digital signal into signals from the mobile terminals 1 existing vtithin the cell managed by each base station in qxiestion by using the scrambling code set up by the uplink code generator 47, and demultiplexes the signal from each of the mobile terminals into signals on channels of each of the mobile terminals 1 by using the channelization code set up by the uplink code generator 47. The signal on the dedicated channel, among the signals demodulated by the demodulating unit 46, is sent to the uplink dedicated channel receiving unit 48, while the signal on the shared channel, among the signals reproduced by the demodulating unit 46, is sent to the uplink shared channel receiving unit 49. Each of the uplink dedicated channel receiving unit 4 8 and the uplink shared channel receiving unit 49 carries out channel decoding (decoding) of the signal inputted thereto, and transmits the channel-decoded signal to a base station control apparatus 3. [0083] Next, each base" station control apparatus ,3 which cdnstructs the mobile communications system in accordance with the present invention will be explained. Fig. 5 is a diagram showing the structure of each base station control apparatus shown in Fig. 1. In Fig. 5, each base station control apparatus 3 relays between a process on a core network, and the wireless circuit of each base station 2, has a function of mainly managing 3;adio vtiwources to establish or release channels to each base station 2, and so on, and includes a transmis-sion and reception processing unit 50, a base station transmission'and reception processing unit 51, a QoS parameter mapping unit 52, a radio resource control unit 53, and a radio link control unit 54. [0084] The transmission and reception processing unit 50 is a component for connecting with either the core network or another base station control apparatus 3, and performs either a communications protocol processing based on a protocol such as RANAP (Radio Access Network Application Part) on the core network, or a communications protocol processing based on a protocol such as RNSAP (Radio Network Subsystem Application Part) on another RNC. The base station transmission and reception processing unit 51 performs a communications protocol processing based on a protocol such as NBAP (Node B Application Part) on each base station 2. The QoS parameter mapping unit 52 acquires the parameters of a radio channel which satisfies requirements on the basis of a QoS (Quality of Service) instruction from the core network. [0085] The radio resource control unit 53 performs a process regarding radio resources, and also informs control information and the parameters to each mobile terminal 1 by using RRC_ signaling. The radio link control unit 54 performs buffering, and retransmission control in a radioMik. The division of the functions among these components is defined logically, and the functions are not necessarily divided clearly in a case in which they are actually implemented via hardware and software. [0086] Next, the operation of the mobile communications system in accordance with Embodiment 1 of the present invention will be explained. Fig. 6 is a flow chart showing a notification process of notifying emergency information which is carried out by the mobile communications system in accordance with Embodiment 1, and the details of the operation will be explained with reference to this figure. In Embodiment 1, a case in which when a base station 2 is transmitting MBMS data which are not emergency information and a mobile terminal 1 is receiving the MBMS data which is not emergency information, the base station notifies emergency information to this mobile terminal 1 will be described. [0087] First, the content provider transmits multimedia data to be transmitted to the mobile terminal 1 to the service center 6. The service center 6 stores the multimedia data in the internal memory thereof, and also transfers the multimedia data to the SGSN 4 that manages the mobile terminal l using this multimedia service via the GGSN 5. The SGSN 4 transmits the multimedia data to the base station 2 via a base station control apparatus 3. [0088] The base station 2 determines whether or not emergency information is included in the multimedia data received from the base station control apparatus 3 (step STl) . For example, the downlink shared channel transmitting unit 3 6 of the base station 2 determines the presence or absence of emergency information by determining whether or not it has received multimedia data which are emergency information. The multimedia data which are emergency information transmitted to the base station 2 can be either so-called wide area emergency information having the same description among a large number of base stations 2, or so-called local emergency information limited to a local area and having the same description in only the base station,;2.or among a small number of base stations 2, [0089] When, in step STl, determining that there is no emergency information, the base station makes a transition to a process of step ST4. In contrast, when determining that there is emergency information, the downlink shared channel transmitting unit 36 of the base station 2 sets a digital value showing "presence" to the emergency information flag included in the MCCH to be transmitted via the S-CCPCH used for transmission of the multimedia data which are emergency information (step ST2) . For example, in a case in which the emergency information flag is one bit of digital data, and is defined in such a way that a digital value of 1 shows the presence of emergency information and a digital value of 0 shows the absence emergency information, the downlink shared channel transmitting unit 36 changes the value of the emergency information flag from the digital value of 0 to the digital value of 1. [0090] - Next, the base station 2 adds information (referred to as emergency information channel information from here on) required for the mobile terminal 1 to receive the emergency information channel to the MCCH (step ST3) . In this case, as the emergency information channel information, for example, emergency information channel number can be considered. This emergency information channel information is added to the MCCH by the downlink shared channel transmitting unit 36. [0091] In a case in which the emergency information channel information is determined in advance by the mobile communications system, and both the mobile terminal 1 and the base station 2 in this mobile communications system recognize this information, the base station 2 does not need to deliver this information to the mobile terminal 1. In this case, step ST3 can be omitted. By thus omitting this step, the processing load on the base station 2 can be reduced, and the radio resources can be used effectively for the other processes. [0092] AS an alternative, in a case in which the emergency information channel information is determined by the base station 2, step ST3 can be omitted when this base station 2 delivers the emergency information channel information to mobile terminals 1 existing within the cell thereof and being under the control thereof in advance. For example, the broadcast information transmitting unit 34 of the base station 2 sets this information as a part of broadcast information and delivers the broadcast information to the mobile terminals in advance by using the P-CCPCH. Also by doing in this way, the ■ processing load on the base station 2 can be reduced, and the radio resources can be used effectively for the other processes. ■ [00931 When, in step STl, determining that there is no emergency information, or when the process of step ST3 is completed, the base station 2 transmits the MCCH to the mobile terminals 1 being under the control thereof (step ST4) . in contirtst, when determining that there is emergency information, the downlink shared channel transmitting unit 36 of the base station 2 maps the emergency information which the base station 2 has received via the base station control apparatus 3 to the emergency, information channel included in the MTCH (step STB) . After that, through the above-mentioned transmitting process, the base station 2 transmits the MTCH to the mobile terminals 1 being: under the control thereof, which receive the MBMS within the. cell thereof, via the antenna 42 (step ST6) . The order of the processes of steps ST2 to STB can be arbitrary, or these processes can be simultaneously carried out. [0094] When receiving the MCCH transmitted from the base station 2 (step ST7) , the mobile terminal 1 determines the presence or absence of emergency information from the value of the emergency information flag included in this MCCH (step ST8) . For example, the description of the MCCH received by the mobile terminal 1 is informed to the control unit 33 of the mobile terminal 1, and the control unit 33 determines the presence or absence of emergency information on the basis of the value of the emergency information flag included in the MCCH. In this case, when determining that there is no emergency information from the value of the emergency information flag, the mobile terminal 1 returns to the process of-'step ST7. [0095] In contrast, when, in step ST8, determining that there, is emergency information, the mobile terminal 1 starts receiving the emergency information channel included in the MTCH according to the emergency information channel information included in the MCCH received in step ST7 (step ST9) . In Fig. 3, according to the emergency information channel information. the control unit 3 3 controls the code generator 23 and the finger assignment control unit 25 to receive the emergency infoimation channel included in the MTCH via the S-CCPCH for the MBMS by using the receiving unit 2 0b. -" [0096] By thus disposing the emergency information flag for setting up the presence or absence of emergency information in the MCCH, a mobile terminal 1 which is receiving MBMS data can always monitor the emergency information flag by simply receiving this MCCH at all times. Therefore, the provision of the emergency information flag is very effective for delivery of emergency information to users through mobile terminals 1. [0097] In a case in which, in step ST9, the emergency information channel information is determined in advance in the mobile communications system, and both the mobile terminal 1 and the base station 2 in this mobile communications system recognize this information, the mobile terminal 1 starts receiving the emergency information channel included in the MTCH according to this information. As an alternative, in a case in which the emergency information channel information is determined by the base station 2, this base station 2 sets the emergency information channel information as a part of broadcast information and delivers this broadcast information to the ■mobile terminals 1 existing within the cell thereof -and being under the .control thereof by using, for example, the P-CCPCH ip. advance. In this case, the mobile terminal 1 can start receiving the emergency information channel included in the MTCH according to the emergency information channel information I delivered thereto in advance. [0098] When, in step ST9, receiving the emergency information channel, the mobile terminal 1 can cancel information (referred to as existing information for MBMS reception from here on) required to receive MBMS data which the mobile terminal 1 has been receivingantil then, or can store the existing information for MBMS reception in the internal memory thereof separately from the emergency information channel information. By thus storing the existing information for MBMS reception separately from the emergency information channel information, the mobile terminal can promptly return to the reception of MBMS data which the mobile terminal 1 has been receiving until then by using the existing information for MBMS reception when the emergency situation is released and the mobile terminal 1 does not need to receive the emergency information channel anymore (or when the transmission of the emergency information channel from the base station 2 is stopped). [0099] When, in step ST9, receiving the emergency information channel, the mobile terminal 1 stops the reception of MBMS data which each of the mobile terminals 1 has been receiving until then. In this case, if the mobile terminal 1 has a radio capability of being able to receive a plurality of MBMS data simultaneously,- the mobile terminal 1 can receive MBMS data whtrh the mobile terminal 1 has been receiving until then, as well as data on the emergency information channel. In this case, the mobile terminal 1 needs to store the existing information for MBMS reception separately from the emergency information channel information therein. flOO] In addition, in a case in which the mobile terminal 1 has an application capability of being able to simultaneously provide a plurality of MBMS data for the user, the mobilei terminal 1 can provide MBMS data which the mobile terminal 1 has been receiving until then, as well as data on the emergency-information channel, for the user. Also in this case, the_ mobile terminal 1 needs to store the existing information for MBMS reception separately from, the emergency information channel information therein. [0101] As mentioned above, according to this Embodiment l, because an emergency information flag (an emergency information indicator) indicating the presence or absence of emergency information is disposed in the MCCH which mobile terminals 1 which support the MBMS can monitor, even if a mobile terminal 1 is receiving MBMS data which are not emergency information, the mobile terminal 1 can check the presence or absence of emergency information at regular intervals from the value of the emergency information flag disposed in the MCCH, and, when determining that there exists emergency information, can receive the emergency information via the emergency information channel which is a channel included in the MBMS. [0102] - . -' Especially, because the emergency information flag (thef emergency information indicator) which is disposed, as the element indicating the presence or absence of emergency,,.,, information, in the MCCH can be expressed as digital data having a small number of bits, the amount of information added into the MCCH in order to apply this Embodiment 1 can be reduced. [0103] Furthermore, because each mobile terminal 1 receives the emergency information data included in the MBMS according to the value of the emergency information flag, each mobile terminal 1 can receive the emergency information data included in the MBMS at an early time without receiving any other unnecessary information and without causing the user to perform an operation of selecting the emergency information channel when receiving the emergency information, and therefore the immediacy of the emergency information can be ensured sufficiently. In addition, because each mobile teinninal 1 does not need to receive any other MCCH information even in a case in which there is no emergency information, each mobile terminal 1 can reduce its power consumption. [0104] Furthermore, in accordance with Embodiment 1, because both the emergency information flag and the emergency information channel information are disposed in the MCCH, emergency information can be delivered with a larger amount of information as compared with a case in which, for example, information regarding emergency information is set up as broadcast information to be carried on the BCCH or the like, like in the case of the emergency information notifying system disclosed .by patent reference 1. [0105] Embodiment. 2. A mobile communications system in accordance with this Embodiment 2 notifies the occurrence of emergency information to even a mobile terminal which is communicating individual data, such as data about a voice call or packets, but is not receiving amy MBMS data, thereby enabling the mobile terminal to receive an emergency information channel included in an MBMS. [0106] Although the fundamental structures of each mobile terminal, each base station, and each base station control apparatus which are disposed in the mobile communications system in accordance with Embodiment 2 are the same as those according to above-mentioned Embodiment 1 shown in Figs. 1 to 5, they differ from those of Embodiment 1 in that when emergency information occurs, each base station transmits an MICH to mobile terminals before transmitting an MCCH, and a mobile teinninal which is communicating individual data, such as data about a voice call or packets, but is not receiving any MBMS data receives the MCCH according to the description of the indicator of the MICH, and then determines the presence or absence of the emergency information from the value of an emergency information flag included in the MCCH and receives the emergency information by using the MBMS. Hereinafter, the structure of the mobile communications system in accordance with this Embodiment 2 will be explained similarly with reference to Figs. 1 to 5. [0107] The MICH is an indicator channel which every time when the channel information of the MBMS is updated and the description of the MCCH (MBMS control information channel) required for reception of MBMS data is updated, each base station 2 notifies to each mobile tenninal 1 which supports the MBMS before transmitting the MCCH, in order to show ther" description of the update. More specifically, if each mobile terminal 1 receives the MICH and monitors the description of the MICH even when not receiving any MBMS data, and the description of the indicator of the MICH shows a service or service group which each mobile terminal desires to receive by using the MBMS, each mobile terminal 1 can start receiving the MCCH and can receive data about the service by using the MBMS. . [0108] In accordance with Embodiment 2, even a mobile terminal 1 in a state of not receiving any MBMS service because of a telephone call or data communications monitors the MICH and starts receiving the MCCH when the description of the indicator included in this MICH shows that emergency information is included. Each mobile terminal 1 determines the presence or absence of emergency information by detecting the emergency information flag disposed in the MCCH, like that of above-mentioned Embodiment 1. Therefore, a mobile terminal 1 which is not receiving the MBMS can check the presence or absence of emergency information at regular intervals by performing these operations at regular intervals, and, when determining that there exists emergency information from the value of the emergency information flag included in the MCCH, can receive the emergency information channel included in the MBMS. [0109] Furthermore, in accordance with this Embodiment 2, when ■ recognizing-the existence of emergency information during communications of individual data, such as audio data or packets, each mobile terminal 1 notifies the occurrence of the emergency information to the user with vibrations, icon blinking, a display of characters, or the like. Accordingly, the mobile communications system can notify the occurrence of the emergency information to users without affecting packet communications, such as Web browsing or a telephone call. [0110] Next, the operation of the mobile communications system will be explained. Fig, 7 is a flow chart showing a notification process of notifying emergency information which is carried out. by the mobile communications system in accordance with Embodiment 2, and the details of the operation will be explained with reference to this figure. In Embodiment 2, a case in which a base station 2 is carrying out a voice call or data communications with a mobile terminal 1, and then notifies emergency information to this mobile terminal 1 will be described. [0111] First, the base station 2 is communicating individual data, such as audio data or packets, with the mobile terminal 1 by using a DTCH or DCCH which is mapped to a DPCH (steps STla and ST9a). At this time, a content provider transmits multimedia data to be transmitted to the mobile terminal 1 to a service center 6. The service center 6 stores the multimedia data in its internal memory, and also transfers the multimedia data to an SGSN 4 which manages the mobile terminal 1 using this • multimedia service via a GGSN 5. The SGSN 4 transmits the . multimedia data to the base station 2 via a base station-control : apparatus 3. -' : - - [0112] ' "" Next, the base station 2 determines whether or not the multimedia data received from the ba»« station control apparatus 3 have emergency information (step ST2a), like that of above-mentioned Embodiment 1. For example, a downlink sha£-ed channel transmitting unit 3 6 of the base station 2 determineBr'ttie presence or absence of emergency information by determining whether or not it has received multimedia data which are emergency information. The multimedia data which are emergency.information transmitted to the base station 2 can be either so-called wide area emergency information having the same description among a large number of base stations 2, or so-calledlocal emergency information limited to a local area -■ and having the same description in only the base station 2 or among a small number of base stations 2. [0113] When, in step ST2a, determining that there is no emergency information, the base station returns to the process of step STla. In contrast, when determining that there is emergency information, the downlink shared channel transmitting unit 36 of the base station 2 sets a digital value showing "presence" to the emergency information flag included in the MCCH to be transmitted via an S-CCPCH used for transmitting the multimedia data which are emergency information (step ST3a) . For example, in a case in which the emergency information flag is one bit of digital data, and is defined in such a way that a digital value of 1 shows the presence of emergency information and a digital va.lue of o shows the absence of emergency information,,. the downlink shared channel transmitting unit 36 changes the . value of the emergency information flag from the digital value;.-" of 0 to'the digiral value of 1. [0114] Next, the base station 2 adds information (emergency information channel information) required for the mobile terminal 1 to receive the emergency information channel to the MCCH (step ST4a) . In this case, as the emergency information channel information, for example, the emergency information channel'number can be considered, like that of above-mentioned Embodiment 1. This emergency information channel information is added to the MCCH by the downlink shared channel transmitting unit 36. [0115] In a case in which the emergency information channel information is determined in advance by the mobile communications system, and both the mobile terminal 1 and the base station 2 in this mobile communications system recognize this information, the base station 2 does not need to deliver this information to the mobile terminal 1. In this case, step ST4a can be omitted. By thus omitting this step, the processing load on the base station 2 can be reduced, and the radio resources can be used effectively for the other processes. [0116] Furthermore, in a case in which the emergency information channel information is determined by the base station 2, step ST4a can be omitted when this base station 2 delivers the emergency information channel information to mobile terminals 1 existing within the cell thereof and being under the control thereof in advance. For example, a broadcast information transmitting unit 34 of the base station 2 sets this information as a part of broadcast information and delivers the broadcast information to the mobll* "terminals ±n advance by using a P-CCPC!H5*jl4«©'by doTng in this way, the processing load on the base station 2 can be reduced, and the radio resotnrces can be used effectively for the other processes. [0117] After the description of the MCCH is updated in step ST4a or the process of step ST4a is omitted as mentioned above, and the existence of emergency information is recognized in step ST2a and the emergency information flag included in the MCCH is then set to "presence" in step ST3a, the base station 2 changes the digital value of the desired indicator for notification in each of MICH frames corresponding to all the services or service groups. For example, in a case in which the indicator for notification is 2-bit digital data and is set up in such a way that a digital value of 11 shows that there is a change in the_ MCCH and a digital value of 00 shows that there is no change in the MCCH, the base station changes the indicator for notification from the digital value of 00 to the digital value of 11. The base station 2 transmits the MICH to the mobile terminals 1 being under the control thereof (step ST5a). For example, when the MCCH is updated through the processes of the above-mentioned steps, the downlink shared channel transmitting unit 36 of the base station 2 transmits the MICH to the mobile terminals 1 via an antenna 42 by performing the transmitting process shown in above-mentioned Embodiment 1. [0118] Next, the base station 2 transmits the MCCH to the mobile terminals 1 being under the control thereof (step ST6a) . When determining' that there is emergency information, the downlink shared channel transmitting unit 36 of the base station 2 maps -the emergency information received via the base station control apparatus 3 to the emergency information channel included in the MTCH (step ST7a) . After that, the base station 2 transmits the MTCH to the mobile terminals l being under the control thereof which receive-the MBMS within the cell thereof via the antenna 42 by carrying out the above-mentioned transmitting process (step ST8a). The order of the processes of steps ST3a and ST4a can be arbitrary, and the processes can be carried out simultaneously. [0119] __ : _In step ST9a, the mobile terminal 1 is transmitting and receiving individual data, such as audio data or packets, to and from the base station 2. At this time, when receiving the MICH transmitted from the base station 2 by doing in the above-mentioned way (step STlOa), the mobile terminal 1 determines whether or not the indicator included in this MICH shows the description of the MBMS receive target of the mobile terminal 1 including the emergency information channel (step STlla). For example, the description of the MICH received by the mobile terminal 1 is informed to a control unit 33, and the control unit 33 determines whether the description of the indicator included in the MICH shows a change in the MCCH which is the MBMS receive target of the mobile terminal 1 including the emergency information channel. In this case, when the control unit 33 determines that the description of the indicator does not show a change in the MCCH which is the MBMS receive target of the mobile teinninal 1 including the emergency information channel, the mobile terminal'returns to the process of step ST9a. [0120] In contraatr when the control unit 33, in step STlla, determines that the indicator in the MICH shows the description of the MBMS receive target of the mobile terminal l including the emergency information channel, the mobile terminal 1 receives the MCCH transmitted from the base station 2 in the above-mentioned way (step ST12a), and determines the presence or absence of emergency information from the value of the ;:. emergency information flag included in this MCCH (step ST13a) . For example, the description of the MCCH received by the mobile terminal 1 is informed to the control unit 33, and the control unit 3 3 determines the presence or absence of emergency .- information on the basis of the value of the emergency information flag included in the MCCH. When determining that there is no emergency information from the value of the emergency information flag, the mobile terminal returns to the process of step ST9a. [0121] When, in step ST13a, determining that there is emergency information, the mobile terminal 1 starts receiving the emergency information channel included in the MTCH which is transmitted from the base station 2 in the above-mentioned way according to the emergency information channel information included in the MCCH received in step ST12a (step ST14a). [0122] In a case in which, in step ST14a, the emergency information channel information is determined in advance by the mobile communications system, and both the mobile terminal 1 - and the base station 2 in this mobile communications system -recognize this -information, the mobile terminal, 1 starts receiving the emergency information channel included in the MTCH according to this information. As an alternative, in a case in which the emergency information channel information is determined by the base station 2, this base station 2 sets the emergency information channel information as a part of broadcast information and delivers this broadcast information in advance to the mobile terminals 1 existing within the cell thereof and being under the control thereof by using, for example, the P-CCPCH. In this case, each of the mobile terminals 1 can start receiving the emergency information channel included in the MTCH according to the emergency information channel information delivered thereto in advance. [0123] Thus, each of the mobile terminals 1 is constructed in such a way as to, even when communicating individual data, such as audio data or packets, with a base stations 2, but not receiving any MBMS data, receive the MICH, and, when the indicator of this MICH shows the description of the MBMS receive target including the emergency information channel, starts receiving the MCCH to be able to recognize the presence or absence of emergency information from the value of the emergency information flag. When a mobile terminal 1 is not receiving any MBMS data or when a mobile terminal 1 selects any service, the mobile terminal 1 can monitor the presence or absence of emergency information from a base station 2. Therefore, this embodiment is very effective for notification of emergency information to users through mobile terminals 1. [0124] ' When starting receiving -the emergency information channel, the mobile terminal l notifies the user that it has sta''rted receiving the emergency information with a sound, vibrations, or a display of characters on the screen thereof (step STlSa) . Por example, even when the mobile tenninal is performing either a phone call or packet communications, the control unit 33 of the mobile terminal makes such a notification as mentioned above-of the emergency information by controlling a not-shown audio output unit, vibration mechanism, or display processing unit as the mobile terminal starts receiving the emergency information channel. [0125] As mentioned above, in the moipile communications system according to this Embodiment 2, each base station 2 transmits the MICH to mobile terminals 1 before transmitting the MCCH, and each of the mobile terminals 1 receives the MCCH according to-the description of the indicator of the MICH, artd then determines the presence or absence of emergency information from the value of the emergency information flag included in the MCCH to receive the emergency information by using the MBMS. Therefore, the mobile communications system can notify the occurrence of emergency information to even a mobile terminal 1 which is communicating individual data, such as audio data or packets, but is not receiving any MBMS data to enable the mobile terminal 1 to receive the emergency information channel included in the MBMS. Furthermore, the mobile communications system can notify the emergency information received via the emergency channel included in the MBMS to the user of the mobile terminal 1 which is communicating individual data. [0126] Embodiment 3. - A mobile communications system in accordance with this Embodiment'3 ffe constructed in"such a way as to notify the ' occurrence of emergency information to even a mobile terminal placed in an idle state in which it is not receiving any MBMS data to enable the mobile terminal to receive an emergency Information channel included in an MBMS. Although the fundamental structures of each mobile terminal, each base station, and each base station control apparatus which are disposed in the mobile communications system in accordance with Embodiment 3 are the same as those according to above-mentioned Embodiment 1 shown in Figs. 1 to 5, they differ from those of Embodiment 1 in that when emergency information occurs, each base station transmits an MICH to mobile terminals before transmitting an MCCH, and a mobile terminal placed in an idle state in which it is not receiving any MBMS data receives the MCCH according to the description of the indicator of the MICH, and then determines the presence or absence of the emergency information from the value of an emergency information flag included in the MCCH and receives the emergency information by using an MBMS. Hereinafter, the structure of the mobile communications system in accordance with this Embodiment 3 will be explained similarly with reference to Figs. 1 to 5. [0128] As shown in above-mentioned Embodiment 2, the MICH is an indicator channel which every time when the channel information of the MBMS is updated and the description of the MCCH (MBMS control information channel) required for reception of MBMS data is updated, each base station 2 notifies to a mobile terminal 1 which supports the MBMS before transmitting the MCCH, in order to show the description "of the update. More specifically, if each mobile terminal 1 receives the MICH and monitors the description of the MICH even when not receiving any MBMS data, and the description ofthe indicator of the MICH rtlfiWB a service or service group which eackjKObitoitilMrminal desires to receive.by using the MBMS, each mobile terminal l can start receiving the MCCH and can receive data about the service by using the MBMS. [0129] In accordance with Embodiment 3, even a mobile terminal 1 placed in an idle state of not receiving any MBMS service monitors the MICH and starts receiving the MCCH when the description of the indicator included in this MICH shows that emergency information is included. Each mobile terminal l determines the presence or absence of emergency information by detecting the emergency information flag disposed in tle* MCCH, like that of above-mentioned Embodiment 1. Therefore, a mobile terminal 1 which is not receiving the MBMS can check the presence or absence of emergency information at regular intervals by performing these operations at regular intervals, and, when determining that there exists emergency information from the value of the emergency information flag of the MCCH, can receive the emergency information channel included in the MBMS. [0130] Furthermore, in accordance with this Embodiment 3, when recognizing the existence of emergency information during communications of individual data, such as audio data or packets, each mobile terminal 1 notifies the occurrence of the emergency information to the user with vibrations, icon blinking, a display of characters, or the like, like that of above-mentioned ETobodinvaJj. a.- Accordingly, the mobile communications System can notify the occurrence of the emergency information to users without affecting packet communications, such as a telephone call-oiE-Web browsing. 10X31} Next, the operation of the mobile communications system will be explained. Fig. 8 is a flow chart showing a notification process of notifying emergency information which is carried out by the mobile communications system in accordance with Embodiment 3, and the details of the operation will be explained with reference to this figure. In Embodiment 3, a case in which the. mobile communications system notifies emergency information to. a mobile terminal 1 placed in an idle state in which it is not receiving any MBMS data will be described. [0132] First, when the mobile terminal 1 is placed in an idle state, the base station 2 transmits the PICH to mobile terminals 1 existing within the cell thereof and being under the control thereof cyclically (step STlb). At this time, a content provider transmits multimedia data to be transmitted to the mobile terminal 1 to a service center 6. The seinrice center 6 stores the multimedia data in its internal memory, and also transfers the multimedia data to an SGSN 4 which manages the mobile terminal 1 using this multimedia service via a GGSN 5. The SGSN 4 transmits the multimedia data to the base station 2 via a base station control apparatus 3. [0133] Next, the base station''2 determines whether or not thje multimedia data received from the base station control-, apparatus 3 have emergency information (step ST2b) , like that., of above-mentiowiHSflrfDOdiment 1. For example, a downlink shared channel transmitting unit 3 6 of the base station 2 determines the presence or absence of emergency information by determining whether or not it has received multimedia data which are emergency information. The multimedia data which are emergency information transmitted to the base station 2 can be either so-called wide area emergency information having the same description among a large number of base stations 2, or so-called local emergency information limited to a local area and having the same description in only the base station-;2, or among-a small number of base stations 2. [0134] When, in step ST2b, determining that there is no emergency information, the base station returns to the process of step STlb. In contrast, when determining that there is emergency information, the downlink shared channel transmitting unit 3 6 of the base station 2 sets a digital value showing "presence" to the emergency information flag included in the MCCH to be transmitted via an S-CCPCH used for transmission of the multimedia data which are emergency information (step ST3b). For example, in a case in which the emergency infomnation flag is one bit of digital data, and is defined in such a way that a digital value of 1 shows the presence of emergency information and a digital value of 0 shows the absence of emergency information, the downlink shared channel transmitting unit 36 changes the value of the emergency information flag from the digital value of 0 to the digital value of 1. [0135] . . " Next, the base station 2 adds information (emergency information channel information) required for the mobile terminal 1 to receive the emergency information channel to the MCCH (step ST4b). As the emergency information channel information, for example, the emergency information channel number can be considered, as in the case of above-mentioned Embodiment 1. This emergency information channel information is added to the MCCH by the downlink shared channel transmitting unit 36. [0136] In a case in which the emergency information channel information is determined in advance by the mobile communications system, and both the mobile terminal 1 and the base station 2 in this mobile communications system recognize this information, the base station 2 does not need to deliver this information to the mobile terminal 1. In this case, step ST4b can be omitted. By thus omitting this step, the processing load on the base station 2 can be reduced, and the radio resources can be used effectively for the other processes. [0137] Furthermore, in a case in which the emergency information channel information is determined by the base station 2, step ST4b can be omitted when this base station 2 delivers the emergency information channel information to the mobile terminals 1 existing within the cell thereof and being under the control thereof in advance. For example, a broadcast information transmitting unit 34 of the base station 2 sets this information as a part of broadcast information and delivers the broadcast information to. the mobile terminals in advance by using a P-CCPCH. Also by doing in this way, the-processing load on the base station 2 can-be reduced, and the radio resources can be used effectively for the other processes. [0138] After the description of the MCCH is updated in step ST4b or the process of step ST4b is omitted as mentioned above, and thft-jristence of emergWOCJ': information is recognized in step ST2b and the emergency information flag included !» tfWF'WOSi is then set to "presence" in step ST3b, the base station 2 changes the digital value of the desired indicator for notification in each of MICH frames corresponding to all the services or.service groups. For example, in a case in which the indicator for notification is 2-bit digital data and is set up in such a way that a digital value of 11 shows that there is a change in the MCCH and a digital value of 00 shows that there is no change in the MCCH, the base station changes the indicator for notification from the digital value of 00 to the digital value of 11. The base station 2 transmits the MICH to the mobile terminals 1 being under the control thereof (step ST5b). For example, when the MCCH is updated through the processes of the above-mentioned steps, the downlink shared channel transmitting unit 3 6 of the base station 2 transmits the MICH to the mobile terminals 1 via an antenna 42 by performing the transmitting process shown in above-mentioned Embodiment 1. [0139] Next, the base station 2 transmits the MCCH to the mobile terminals 1 being under the control thereof (step ST6b) . When determining that there is emergency information, the downlink shared channel transmitting unit 3 6 of the base station 2 maps the emergency information received via the base station control apparatus 3 to the emergency information channel included in the MTCH (step ST7b) ; "After that, the base station 2 transmits the MTCH to the mobile terminals 1 being under the;control thereof which receive the MBMS within the cell thereof via the antenna 42 by carrying out the above-mentioned transmitting process (step ST8b). The order of the processes of steps ST3b and ST4b can be arbitrary, or the processes can be carried out simultaneously. [014(M The mobile terminal 1, in step ST9b, receives the PICK from the base station 2 and determines the presence or absence of information (PI; Paging Indicator) destined for the mobile terminal J._. For example, the description of the PIGH received by the mobile terminal 1 is informed to the control unit 33, and the control unit 3 3 determines the presence or absence of information destined for the mobile terminal 1 from the PICH. At this time, when the control unit determines that there is information destined for the mobile terminal 1, the mobile terminal 1 starts receiving the S-CCPCH from the base station 2 on the basis of the information destined for the mobile terminal 1 (step STlOb). [0141] In contrast, when the control unit determines that there is no information destined for the local station, the mobile terminal 1 receives the MICH which is transmitted from the base station 2 in the above-mentioned way (step STllb), and determines whether the indicator included in this MICH shows the description of the MBMS receive target of the mobile terminal 1 including the emergency information channel (step ST12b) . For example, the description of the MICH received by the mobile terminal 1 is informed to a control unit 33, and the control unit 33 determines "Whether the description of the indicator included in the MICH shows a change in the MCCH which is the MBMS receive target of the mobile terminal 1 including the emergency information channel. In this case, when the control unit determines that the description of the indicator does not show a change in the MCCH which is the MBMS receive target of the mobile terminal 1 including the emergency information channel, the mobile terminal returns to the process of step ST9b. [0142] •In-- contrast, when the control unit, in step STl2b,,. determines that the indicator shows the description of the MBMS receive target of the mobile terminal 1 including the emergency information channel, the mobile terminal 1 receives the MCCH which is transmitted from the base station 2 in the above-mentioned way (step STl3b) , and determines the presence or absence of emergency information from the value of the emergency information flag included in this MCCH (step ST14b) . For example, the description of the MCCH received by the mobile terminal 1 is informed to the control unit 33, and the control unit 3 3 determines the presence or absence of emergency information on the basis of the value of the emergency information flag included in the MCCH. When determining that there is no emergency information from the value of the emergency information flag-, the mobile terminal returns to the process of step ST9b. [0143] When, in step ST14b, detezHnining that there is emergency information, the mobile terminal 1 starts receiving the emergencry information channel included in the MTCH which- is transmitted from the base station 2 in the above-mentioned way according to the emergency ""information channel information, included in the MCCH received in step ST13b (step ST15b). [0144] In a case in which, in step ST15b, the emergency information channel information is determined in advance by the mobile communications system, and both the mobile terminal 1 and the base station 2 in this mobile communications system recognize this information, the mobile terminal 1 starts receiving the emergency information channel included in the MTCH according to this information.- As an alternative, in a case in which the emergency information channel information is determined by the base station 2, this base station 2 sets the emergency information channel information as a part of broadcast information and delivers this broadcast information to the mobile terminals 1 existing within the cell thereof and being under the control thereof by using, for example, the P-CCPCH. In this case, each of the mobile terminals 1 can start receiving the emergency information channel included in the MTCH according to the Emergency infojrmation channel information delivered thereto in advance. [0145] Thus, each of the mobile terminals 1 is constructed in such a way as to, even when placed in an idle state in which it.is not receiving any MBMS data, receive the MICH, and, when the indicator of this MICH shows the description of the MBMS receive target including the emergency information channel, starts receiving the MCCH to be able to recognize the presence or absence of emergency information from the value of. the emergency information flag. When each of the mobile tejrrni'nals 1 -is not receiving any MBMS data or selects any servicer each mobile terminal 1 can monitor the presence or absence of emergency information from a base station 2. Therefore, this embodiment is very effective for notification of emergency information to users throa«-mobile terminals l. [0146] When starting receiving the emergency information channel, the mob'ile terminal 1 notifies the user that it has started receiving the emergency information with a sound, vibrations, or a display of characters on the screen -thereof (step ST16b) . For example, even when the mobile terminal is performing either a phone call or packet communications, the control unit 3Tof the mobile terminal makes such a notification as mentioned above of the emergency information by controlling a not-shown audio output unit, vibration mechanism, or display processing unit as the mobile terminal starts receiving the emergency information channel. [0147] As mentioned above, in the mobile communications system according to this Embodiment 3, each base station 2 transmits the MICH to mobile terminals 1 before transmitting the MCCH, and each of the mobile terminals 1 receives the MCCH according to the description of the indicator of the MICH, and then determines the presence or absence of emergency information from the value of the emergency information flag included in the MCCH to receive the emergency information by using the MBMS. Therefore, the mobile communications system can notify the occurrence of emergency information to even a mobile terminal 1 placed in an idle state in which it is not receiving any MBMS data to enable themobile terminal 1 to receive the emergency information channel included in the MBMS. FurthermaiT, the mobile communicatioas, system can notify the em'irgency infbrrfEation received via the emergency channel included' in the MBMS to the user of the mobile terminal 1 which is communicating individual data. [0148} In above-mentioned Embodiments 2 and 3, as the method of making the indicator included in the MICH show a description including emergency information, a method of, when the emergency information flag included in the MCCH is set to "presence", changing the digital value of the desired indicator for notification of each of MICH frames corresponding to all the services or service groups. As another method, there is a method of disposing an indicator used for notification of change in the emergency information flag included in the MCCH in each of all the MICH frames. in this case, when the emergency information flag included in the MCCH is set to "presence" in step ST3a or ST3b, the base station 2 changes the digital value of the indicator used for notification of change in the emergency information flag included in the MCCH of each of MICH frames corresponding to all the services or service groups. For example, in a case in which the indicator used for notification of change in the emergency information flag included in the MCCH is 2-bit digital data and is set up in such a way that a digital value of 11 shows that there 'is a change in the MCCH and a digital value of 00 shows that there is no change in the MCCH, the base station changes the indicator for notification from the digital value of 00 to the digital value of'11. The mobile teinninal 1, in step STlla or ST12b, receives an MICH frame corresponding to a service 'which the mobile terminal desires to receive to 'atermine whether or not there is a change in the MC?CH from the desired indicator, and also monitors the indicator used for notification of change in the emergency information flag included in thg MCCH, the indicator being included in the same MICH frame, to determine whether or not the emergency information flag included in the MCCH is set to "presence" . The indicator used for notification of change in the emergency information flag included in the MCCH can be digital data having the same number of bits as another indicator for notification. As mentioned above, because the indicator used for notification of change in the emergency information flag, included in the MCCH is disposed in each of.all the MICH frames, and the mobile terminal receives only the indicator used for notification of change in the emergency information flag included in the MCCH even in a case of not having any service or service group which the mobile terminal desires to receive-at normal times (not in case of an emergency) , there is provided an advantage of being able to determine whether or not the MCCH emergency information flag in case of an emergency is set to "presence" is acquired. Furthermore, because the indicator used for notification of change in the emergency information flag included in the MCCH is disposed in each of all the MICH frames, the mobile terminal can receive any of the MICH frames and carry out flexible scheduling between the base station and the mobile terminal. [0149] As a further method, there is a method of setting up a service or service group used for the MCCH emergency information channel. In this case, when the emergency information flag • included in the MCCH is set to "presence" in step ST3a or ST3b, the base station" 2'Changes the digital value of the indicator-\ used for notification of change in the emergency information flag included in the MCCH of an MICH frame corresponding to the service or service group used for the MCCH emergency information channel. For example, in a case in which the indicator used for notification of change in the emergency information flag included in the MCCH is 2-bit digital data and is set up in such a way that a digital value of 11 shows that there is a change in the MCCH and a digital value of 0 0 shows that there is no change in the MCCH, the base station changes the indicator for notification from the digital value of 00 to the digital value of 11. The mobile terminal 1, in step STlla or ST12b, determines whether or not the emergency information flag included in the MCCH is set to "presence" from the indicator used for notification of change in the emergency information flag included in the MCCH, the indicator being included in the MICH frame corresponding to the seiryice or service group used for the MCCH emergency information channel. The indicator used for notification of change in the emergency information flag included in the MCCH can be digital data having the same number of bits as another indicator for notification of a service or service group. As mentioned above, because the service or service group used for the MCCH emergency information channel is set up in advance, and the mobile terminal receives only an MICH frame I corresponding to the service or service group used for the emergency information channel included in the MCCH even in a case of not having any service or service group which the mobile terminal desires to. receive at normal times (not in case of an emergency), there is provided an advantage of being able to > enajjin the ragbile terminal to determine whether or not the MCCH emergency information flag included in the frame in case of an emergency issat to "presence". EO150] In above-mentioned Embodiments 2 and 3, a case in which ) a mobile terminal is placed in either a state (CELL_DCH state) in which it is communicating individual data or an idle state (Idle state) is disclosed, though the method of disposing'*,Ja# emergency information flag in the MCCH, and enabling the mobile terminal to receive the MICH, receive the MCCH according to the. description of the indicator to determine the presence or ahsence of emergency information from the value of the emergency information flag included in the MCCH, and receive the emergency information by using an MBMS can be applied not only to the above-mentioned states, but also to a CELL_FACH state, a CELL_PCH state, and a URA_PCH state. Therefore, the mobile communications system enables each mobile terminal to receive the emergency information data regardless of in which state each mobile terminal is placed, and to receive the emergency information data included in the MBMS at an earlier time without receiving any other unnecessary information and without causing the user to perform an operation of selecting the emergency infttttnation channel when receiving the emergency information, thereby sufficiently ensuring the immediacy of the emergency information. [0151] In above-mentioned Embodiments 2 and 3, the method of making each mobile terminal receive the MICH and receive the MCCH according to the description-of the indicator is disclosed. Instead of the MICH, a PICH. .can be used. Concretely, an indicator used for notificatiori of change in the emergency information flag included in the MCCH can be disposed in each of all PICH frames. In this case, when, in step ST3a or 3X31?, the emergency information flag included in the MCCH is set to "presence", the base station 2 changes the digital value of the indicator used for notification of change in the emergency information flag included in the MCCH of each of PICH frames corresponding to all the mobile terminals or mobile terminal groups. For example, in a case in which the indicator used for notification of change in the emergency information flag included in the MCCH is 2-bit digital d.ata and is set up in such a way that a digital value of 11 shows that there is a change in the MCCH and a digital value of 00 shows that there is no change in the MCCH, the base station changes the indicator for notification from the digital value of 0 0 to the digital value of 11. Each mobile terminal 1, in step STlla or ST12b, receives a PICH frame corresponding thereto, and monitors the indicator used for notification of change in the emergency information flag included in the MCCH which is included in the PICH frame to determine whether or not the emergency information flag included in the MCCH is set to "presence". The indicator used for notification of change in the emergency information flag included in the MCCH can be digital data having the same number of bits as another indicator (a paging indicator) in the PICH frame. When, in step STlla or ST12b, determining that the emergency information flag included in the MCCH is set to "presence", each mobile terminal immediately makes a transition to an operation of receiving the MCCH in step STl2a or ST13b. [0152] - " As another method, there can be,a method of setting up a PICH frame used for the MCCH emergency information channel. In this case, when, in step STSa or ST3b, the emergency infoicraatiorvf lag included ia ttie MCCH is set to "presence", the base station 2 changi»s the digital value of the indicator used for notification of change in the emergency information flag f included in the MCCH of the PICH frame used for the MCCH emergency information channel. For example, in a case in which the indicator used for notification of change in the emergency information flag included in the MCCH is 2-bit digital data and is seS. up in such a way that a digital .value of 11 shows that there x§ a change in the MCCH and a digital value of 00 shows , that there is no change in the MCCH, the base station changes the indicator for notification from the digital value of 0 0 to the digital value of 11. Each mobile terminal 1, in step STlla or ST12b, determines whether or not the emergency information flag included in the MCCH is set to "presence" from the indicator used for notification of change in the emergency information flag included in the MCCH, the indicator being included in the PICH frame used for the MCCH emergency information channel. When, in step STlla or ST12b, determining thatt the emergency information flag included in the MCCH is set to "presence", each mobile terminal immediately makes a transition to an operation of receiving the MCCH in step ST12a or ST13b. Each mobile terminal typically receives the PICH when placed in an idle state (Idle state) . Each mobile terminal can be made to receive the PICH when placed not only in the idle state, but also in a CELL_DCH state, a CELL_FACH state, a CELL_PCH state, and a URA.__PCH state. Therefore, the mobile communications system enables each mobile terminal to recye the emergency information data regardlessof in which state ech mobile terminal is placed, and to receive the emergency information data included in the MBMS quickly without receiving arty other unnecessary information, such as a BCCH, and without causing the user to perform an operation of selecting the emergency information channel when receiving the emergency D iiltfontektion, thereby sufficiently ensuring the immediacy of the emergency information. [0153] In above-mentioned Embodiments 1 to 3, each base station 2 determines whether or not multimedia data received from a base station control apparatus 3 have emergency information, and, when determining that there is emergency information, sets a digital value showing "presence" to the emergency information flag included in the MCCH which is transmitted via the S-CCPCH used for transmission of multimedia data which are the emergency information, adds information (emergency information channel information) required for mobile terminals 1 to receive the emergency information channel to the MCCH, and maps the emergency information to the emergency information channel included in the MTCH. As an alternative, base station control apparatuses 3 can perform these processes. [0154] A concrete example will be shown. A base station control apparatus 3 to which multimedia data are transmitted from the SGSN 4, in step STl, ST2a, or ST2b, determines whether or not there is emergency information. For example, a radio resource control unit 53 of the base station control apparatus 3 determines the prisence or absence of emergency information by determining whether or not the base-stotion control apparatus has received multiinedia data which are emergency information. When determining that there is no emeiigency information, the base station control apparatus 3 makes a transition to the process of step ST4, ST5a, or ST5b. In contrast, when determining that there is emergency information, the radio resource control unit 53 of the base station control apparatus 3 sets a digital value showing "presence" to the emergency information flag included in the MCCH which is transmitted via the S-CCPCH used for transmission of the multimedia data which are emergency information (step ST2, ST3a, or ST3b). For example, in/a case in which the emergency information flag is 1-bit digitai data and is set up in such a way- that a digital value of 1 shows that there is emergency inf.ormation and a digital value of 0 shows that there is no emergency information, the radio resource control unit 53 changes the emergency informatioaf lag from the digital value of 0 to the digital value of 1. • [0155] Next, the base station control apparatus 3 adds the emergency information channel information to the MCCH (step ST3, ST4a, or ST4b). In this case, as the emergency information channel information, for example, the emergency information channel number can be considered. This emergency information channel information is added by the radio resource control unit 53, In a case in which the emergency information channel information is determined in advance by the mobile communications system, and both the mobile terminal 1 and the base station control apparatus 3 in this mobile communications system recognize this information, the base station control apparatus 3 dt>es not need to deliver this information to the mobile terminal 1 via the base station 2. In this case, steps ST3, ST4a, and"'ST4b can be omitted. By thus omitting this step, the processing load on the base station control apparatus 3 can be reduced, and the radio resources can be used effectively for the other processes. Furthermore, in a case in which the emergency information channel information is determined B tfiS base station control apparatus 3, step ST3 can be omitted when this the base station control apparatus 3 delivers, via the base station 2, the emergency information channel information to mobile terminals 1 existing within the cell of the base station 2 and being under the control of the base station 2 in advance. For example, a broadcast information transmitting unit 34 of the base station 2 sets this information as a part of broadcast information and delivers' the broadcast information to the mobile terminals in advance by using a P-CCPCH. Also by doing in this way, the processing load on the base station control apparatus 3 can be reduced, and the radio resources can be used effectively for the other processes. [0156] When, in step STl, ST2a, or ST2b, determining that there is no emergency information, or when the process of step ST3, ST4a, or ST4b is completed, the base station control apparatus 3 transmits, via the base station 2, the MCCH to the mobile terminals 1 being under the control of the base station 2 (step ST4, ST6a, or ST6b). In contrast, when there is emergency information, the radio resource control unit 53 of the base station control apparatus 3 maps the emergency information to the emergency information channel included in the MTCH (step ST5, ST7a, or ST7b). After that, the base station control apparatus 3 causes the base station 2 to transmit the MTCH to the mobile terminals 1 Being under the control thereof which receive the MBMS within the cell thereof via the antenna 42 by maJcing. the base station 2 perform the above-mentioned transmitting process (step 316, ST8a, or ST8b). The order of these processes can be arbitrary, or these processes can be carried out simultaneously. ... [0,157] As mentioned above, each base station control apparatus 3 is constructed in such a way as to determine whether or not received multimedia data have emergency information, and, when determining that the received multimedia data have emergency information, set a digital value showing "presence" to the emergency information flag included in the MCCH which is transmitted via the S-CCPCH used for transmission of the. . multimedia data which are the emergency information, and then perform the process of adding the information (emergency-information channel information) required for mobile terminals 1 to receive the emergency information channel into the MCCH. Therefore, the present embodiment offers an advantage of being able to enable each of a plurality of base stations 2 to transmit so-called wide area emergency information having the same description without carrying out the above-mentioned processes, thereby enabling a mobile terminal staying at an end of a cell to combine the received powers from the above-mentioned plurality of base stations 2. As a result, the quality of reception of the emergency information of the mobile terminal can be improved, and the emergency information can be transmitted correctly and quickly to the mobile terminal. [0158] Embodiment 4. A mobile communications system in accordance with this. Embodiment 4, notifies the occurrence of emergency information to even a mobile terminal which is receiving individual data which are not emertjcucy information by using an emergency information flag disposed in a BCCH so as to enable the mobile termtnail to receive an emergency information channel included in an MBMS. [0159] Although the fundamental structures of each mobile terminal, each base station, and each base station control apparatus which are disposed in the mobile communications system in accordance with Embodiment 4 are the same .as those according to above-mentioned Embodiment 1 shown in Figs. 1 to 5, they differ from those of Embodiment 1 in that the emergency information flag (emergency information indicator) showing the presence or absence of emergency infoinnation is disposed in the BCCH which is a broadcast control channel, and, when emergency information occurs, each base station transmits the BCCH to mobile terminals, and mobile terminals each of which is receiving individual data which is not emergency information determines the presence or absence of emergency information from the value of the emergency information flag included in the BCCH and then receives the emergency information by using an MBMS. Hereinafter, the structure of the mobile communications system in accordance with this Embodiment 4 will be explained similarly with reference to Figs. 1 to 5. [0160] Next, the operation of the mobile communications system will be explained. Fig. 9 is a flow chart showing a notification process of notifying emergency infoirmation which is carried out by the mobile communications system iii accordance with Embodiment 4, and the details of the operation will be explained with xtft#ll.nge to this figure. In Embodiment 4, a case in which a base station 2 which is transmitting individual data which are not emergency information to a mobile terminal 1 notifies emergency information to this mobile terminal 1 will be described. [0161] First, a content provider transmits multimedia data to be transmitted to the mobile terminal l to a service center 6. The service center 6 stores the multimedia data in its internal memory, and also transfers the multimedia data to an SGSN 4 which manages the mobile terminal 1 using this multimedia service via a GGSN 5. The SGSN 4 transmits the multimedia data to the base station 2 via a base station control apparatus 3. [0162] Next, the base station 2 determines whether or not the multimedia data received from the base station control apparatus 3 have emergency information (step STlc), like that of above-mentioned Embodiment 1. For example, a downlink shared channel transmitting unit 3 6 of the base station 2 determines the presence or absence of emergency information by determining whether or not it has received multimedia data which are emergency information. The multimedia data which are emergency information transmitted to the base station 2 can be either so-called wide area emergency information having the same description among a large number of base stations 2, or so-called local emergency information limited to a local area and having the same description in only ©ne base station 2 or among a small number.-of base stations 2. [0163] When, in step STlc, determining that there is no emergency information, the base station shifts to a process of step ST4c. In contrast, when determining that there is emergency information, the downlink shared channel transmitting unit 36 of the base station 2 sets a digital value showing "presence" to the emergency information flag included in the BCCH to be transmitted via an S-CCPCH used for transmission of the multimedia data which are emergency information (step ST2c) . For example, in a case in which the emergency information flag is one bit of digital data, and is defined in such a way that a digital value of 1 shows the presence of emergency information and a digital value' of 0 shows the absence of emergency information, the downlink shared channel transmitting unit 3 6 changes the value of the emergency information flag from the digital value of 0 to the digital value of 1. [0164] Next, the base station 2 adds BCCH Modify information to PAGING TYPE 2 included in a DCCH (step ST3c) . When the description of the BCCH is changed, the BCCH Modify information shows the description of the change. This information is added by either a downlink dedicated channel transmitting unit 3 5 or the downlink shared channel transmitting unit 36. [0165] The base station 2 then transmits the DCCH to mobile terminals 1 being under the control thereof (step ST4c) . After that, the base station 2 adds information (emergency information channel information) required for the mobile terminal 1 to receive the emergency information channel to an MCCH (step ST5c) . -As the emergency information channel information, for example, the emergency information channel number can be considered, like in the case of above-mentioned Embodiment 1. This emergency information channel information is added to the MCCH by the downlink shared channel transmitting unit 36. [0166] In a case in which the emergency information channel information is determined in advance by the mobile communications system, and both the mobile terminal l and the base station 2 in this mobile communications system recognize this information, the base station 2 does not need to deliver this information to the mobile terminal 1. In this case, step ST5c can be omitted. By thus omitting this step, the processing load on the base station 2 can be reduced, and the radio resources can be used effectively for the other processes. [0167] As an alternative, in a case in which the emergency information channel information is determined by the base station 2, step ST5c can be omitted when this base station 2 delivers the emergency information channel information to mobile terminals 1 being under the control thereof in advance. For example, a broadcast information transmitting unit 34 of the base station 2 sets this information as a part of broadcast information and delivers the broadcast information to the mobile terminal in advance by using a P-CCPCH. Also by doing in this way, the processing load on the base station 2 can be reduced, and the radio resources can be used effectively for the other processes. [0168] Next, the base station 2 transipits the MCCH to the.mobile terminals 1 being under the control thereof (step ST6c) .% When determining that there is emergency information, the downlink shared channel transmitting unit 36 of the base station 2 maps the emergency information received via the base station control apparatus 3 to the emergency information channel included in the MTCH (step ST7c) . After that, the base station 2 transmits the MTCH to the mobile terminals 1 being under the control thereof which receive the MBMS within the cell thereof via an antenna 42 by carrying out the above-mentioned transmitting process (step ST8c) . The order of the processes of ste,ps.-ST2c to ST7c can be arbitrary, or the processes can be carried out simultaneously. [0169] The mobile terminal 1 receives the DCCH which is transmitted from the base station 2 in the above-mentioned way (step ST9c), and determines the presence or absence of BCCH Modify information in PAGING TYPE 2 included in this DCCH (step STlOc) . For example, the description of the DCCH received by the mobile terminal 1 is informed to a control unit 33, and the control unit 3 3 analyzes the description of PAGING TYPE 2 included in the DCCH so as to determine the presence Or absence of BCCH Modify information. In this case, when determining that there is no BCCH Modify information in PAGING TYPE 2, the mobile terminal returns to the process of step ST9c. [0170] In contrast, when, in step STlOc, determining that there is BCCH Modify information in PAGING TYPE 2, the mobile terminal 1 receives the BCCH from the base station 2 (step STllc)., and then determines the. presence or absence of emergency information from the valtie of the emergency information..£lag included in this BCCH- (step ST12c) . For example," the description of the BCCH received by the mobile terminal 1 is informed to the control unit 33, and the control unit 33 determines the presence or absence of emergency information on the basis of the value of the emergency information flag included in the BCCH. When determining that there is no emergency information from the value of the emergency information flag, the mobile terminal 1 makes a transition to a process of step ST15c and, after performing a general BCCH .. update process, returns to the process of step ST9c. [0171] When, in step ST12C, determining that there is emergency information, the mobile terminal 1 receives the MCCH which is , transmitted from the base station 2 in the above-mentioned way (step ST13c), and starts receiving the emergency information channel included in the MTCH which is transmitted from the base station 2 according to the emergency information channel information included in the MCCH (step ST14c). [0172] In a case in which, in step ST14c, the emergency information channel information is determined in advance by the mobile communications system, and both the mobile terminal 1 and the base station 2 in this mobile communications system recognize this information, the mobile terminal 1 starts receiving the emergency information channel included in the MTCH according to this information. [0173] As an alternative, in a case in which the emergency information channel information is determined by the base station 2, this base station 2 sets the emergency information -channel information as a part.of broadcast information and ' delivers this broadcast information in advance to the mobile terminals 1 existing within the cell thereoand being under the control thereof by using, for example, the P-CCPCH. In this case, each of the mobile terminals 1 can start receiving the emergency information channel included in the MTCH according to the emergency information channel information delivered thereto in advance. [0174] As mentioned above, according to this Embodiment 4, because the emergency information flag (emergency information indicator) showing the presence or absence of emergency information is disposed in the BGCH, the mobile communications system can notify the occurrence of emergency information to even a mobile terminal 1 which is receiving individual data which are not emergency information via the BCCH so as to enable the mobile terminal to receive the emergency information channel included in the MBMS. Furthermore, unlike in a case in which the emergency information flag is disposed in the MCCH which only a mobile terminal 1 which supports the MBMS can receive, because even a mobile terminal 1 which does not support the MBMS can receive the BCCH, the base station 2 can notify the presence or absence of emergency information to all the mobile terminals 1 existing within the cell thereof. [0175] In the emergency information notifying system disclosed by patent reference 1, in addition to information showing the presence or absence of emergency information, emergency -'information channel information required in order to receive the emergency information channel is transmitted as, for -example, broadcast information, on the BCCH, the amount of information of the broadcast information increases and there is a possibility that there is a necessity to reduce other information to be delivered as broadcast information. In contrast with this, because the mobile communications system in accordance with this Embodiment 4 is constructed in such a way that only the emergency information flag (emergency information indicator) showing the presence or absence of emergency information is disposed in the BCCH, a minimum amount of information is required in order to notify the presence or absence of emergency information, and there is no necessity to reduce any other information included in the BCCH. Furthermore, the mobile communications system enables each mobile terminal 1 to receive the emergency information data included in the MBMS at an earlier time without receiving, via the BCCH, any other information unnecessary for reception of the emergency information, thereby sufficiently ensuring the immediacy of the emergency information. [0176] Embodiment 5. A mobile communications system in accordance with the present Embodiment 5 is constructed in such a way as to notify the occurrence of emergency information to even a mobile terminal placed in an idle state in which it is not receiving any MBMS data by using an emergency information flag disposed in a BCCH to enable the mobile terminal to receive an emergency information channel included in an MBMS. [0177] Although the fundamental structures of each mobile terminal ■ each base statiori, and each base station control apparatus which are disposed in the mobile communications' system in accordance with Embodiment 5 are the same as those according to above-mentioned Embodiment 1 shown in Figs. 1 to 5, they differ from those of Embodiment 1 in that the emergency information flag (an emrergency information indicator) showing th"presence or absence of emergency information is disposed in the BCCH which is a broadcast control channel, and, when emergency information occurs, each base station transmits the BCCH to mobile terminals and a mobile terminal placed in an idle state in which it is not receiving any MBMS data determines the presence or absence of the emergency information from the value of the emergency information flag included in the BCCH. and receives the emergency information by using an MBMS. Hereinafter, the structure of the mobile communications system in accordance with this Embodiment 5 will be explained similarly with reference to Figs. 1 to 5. [0178] Next, the operation of the mobile communications system will be explained. Fig. 10 is a flow chart showing a notification process of notifying emergency information which is carried out by the mobile communications system in accordance with Embodiment 5, and the details of the operation will be explained with reference to this figure. In Embodiment 5, a case in which a base station notifies emergency information to a mobile terminal 1 placed in an idle state in which it is not receiving any MBMS data will be described. [0179] -'First, a base station 2 transmits a PICK to mobile terminals 1 existing within the cell thereof and being under the control thereof cyclically and a mobile terminal 1 is placed in an idle state until it receives information destined therefor via the PICK. At this time, a content provider transmits multimedia data to be transmitted to the mobile terminals 1 to a service center 6. The service center 6 stores the multimedia data in its internal memory, and also transfers the multimedia data to an SGSN 4 which manages the mobile terminal 1 using this multimedia servje via a GGSN 5. The SGSN 4 transmits the multimedia datato the base station 2 via a base station control apparatus 3. [0180] Next, the base station 2 determines whether or not the multimedia data received from . the base station control apparatus 3 have emergency information (step STld), like that of above-mentioned Embodiment 1. For example, a downlink shared channel transmitting unit 36 of the base station 2—• determines the presence or absence of emergency information by determining whether or not it has received multimedia data which are emergency information. The multimedia data which are emergency information transmitted to the base station 2 can be either so-called wide area emergency information having the same description among a large number of base stations 2, or so-called local emergency information limited to a local area and having the same description in only the base station 2 or among a small number of base stations 2. [0181] When, in step STld, determining that there is no emergency information, the base station shifts to a process of step ST4d. In contrast, when determining that there is emergency information, the-downlink shared ;Ghannel transmitting unit 36 of the base station 2 sets a digitals value showing "presence" to the emergency information flag included in the BCCH to be transmitted via an S-CCPCH used for transmission of the multimedia data which are emergency information (step ST2d). For esrawple, in a case in which the emergency information flag is one bit of digital data, and is defined in such a way that a digital value of 1 shows the presence of emergency information and a digital value of 0 shows the absence of emergency information, the downlink shared channel transmitting unit 36 changes the value of the emergency information flag from the digital value of 0 to the digital value of 1. [0182] Next, the base station 2 adds BCCH Modify information to a PCCH (step ST3d) . When the description of the BCCH is changed, the BCCH Modify information shows the description of the change, as shown in above-mentioned Embodiment 4. This information is added by the downlink shared channel transmitting unit 36. [0183] The base station 2 then transmits the PICH to the mobile terminals 1 existing within the cell thereof and being under the control thereof (step ST4d) . After that, the base station 2 adds information (emergency information channel information) required for the mobile terminals 1 to receive the emergency information channel to an MCCH (step ST5d). As the emergency information channel information, for example, the emergency information channel number can be considered, like in the case of above-mentioned Embodiment 1. This emergency information channel information is added to the MCCH by the downlink shared channel transmitting unit 36. [0184] " :■ In a 6-ase in which the emergency information channel information is determined in advance by the mobile communications system, and both the mobile terminal 1 and the base station 2 in this mobile communications system recognize this information, the base station 2 does not need to deliver this information to the mobile terminal 1. In this case, step ST5d can be omitted. By thus omitting this step, the processing load on the base station 2 can be reduced, and the radio resources can be used effectively for the other processes. [0185] Furthermore, in a case in which the emergency information channel information is determined by the base station 2, step ST5d can be omitted when this base station 2 delivers the. emergency information channel information to the mobile terminals 1 existing within the cell thereof and being under the control thereof ir. advance. For example, a broadcast information transmitting unit 34 of the base station 2 sets this information as a part of broadcast information and delivers the broadcast information to the mobile terrainals in advance by using a P-CCPCH. Also by doing in this way, the processing load on the base station 2 can be reduced, and the radio resources can be used effectively for the other processes. [0186] Next, the base station 2 transmits the MCCH to the mobile terminals 1 being under the control thereof (step ST6d) . When determining that there is emergency information, the downlink shared channel transmitting unit 3 6 of the base station 2 maps the emergency information received via a base station control apparatus 3 o the emergency information channel included in the MTCH (step ST7d) . After that, the base station 2 transmits; the MTCH to--the mobile terminals 1 being under the control thereof which receive an MBMS within the. cell thereof via an antenna 42 by carrying 6ut the above-mentioned transmitting process (step ST8d) , The order of the processes of steps ST2d to ST7d can be arbitrary, or the processes can be carried out \ simultaneously. [0187] In step ST9d, the mobile terminal 1 receives the PICH from the base station 2 tO" determine the presence or absence of information (PI; Paging Indicator) destined for the mobile terminal 1. For example, the description.of the PICH received by the mobile terminal'l is informed to a control unit 33, and the control unit 3 3 determines the presence or absence of the infoDrmation destined for the local station from the PICH. At this time, when determining that there is no information destined for the local station, the mobile terminal 1 returns to the process of step ST9d and then repeats the reception of the PICH cyclically. [0188] In contrast, when determining that there is information destined for the local station, the mobile terminal 1 starts receiving the S-CCPCH from the base station 2 on the basis of this information destined for the local station (step STlOd), and determines the presence or absence of BCCH Modify inf02rmation in the PCCH transmitted thereto via the S-CCPCH (step STlld) . For example, the description of the PCCH received by the mobile terminal 1 is informed to the control unit 33, and the control unit -33 analyzes the PCCH so as to determine the presence or absence of BCCH Modify information. At this time, when there is -no BCCH Modify information, the mobile terminal 1 determines~whether or not a call-has been made (step ST12d) . In this case, when no call has been made, the mobile terminal returns to the process of step ST9d, whereas when a call has been made, thewabile terminal performs a process of receiving the call to start audio or data communications (step ST13d). [0189] Furthermore, when, in step STlld, determining that there is BCCE, Modify information in the PCCH, the mobile terminaL 1 receives the BCCH from the base station 2 (step ST14d), and determines the presence or absence of emergency information from the value of the emergency inforroation flag included in this BCCH (step STlSd) . -For example, the description of the BCCH received by the mobile terminal 1 is informed to the control unit 33, and the control unit 33 determines the presence or absence of emergency information on the basis of the value of the emergency information flag included in the BCCH. As this time, when determining that there is no emergency information from the value of the emergency information flag, the mobile terminals 1 makes a transition to a process of step ST17d and, after performing a general BCCH update process, returns to the process of step ST9d. [0190] When, in step ST15d, determining that there is emergency information, the mobile terminal l receives the MCCH which is transmitted from the base station 2 in the above-mentioned way (step ST16d), and starts receiving the emergency information channel included in the MTCH which is transmitted from the base station 2 according to_ the emergency information channel information included in-the MCCH (step ST18d) . ■ ■■ .-[0191] - In a case in which, in step STlSd, the emergency information channel informationift,(fi«tb«jKtiiii!£(i in advance by the mobile communications system, and both the mobile terminal 1 and the base station 2 in this mobile communications system recognize this information, the mobile terminal 1 starts receiving the emergency information channel included in the MTCH according to this information. Furthermore, in a case in which the emergency information channel information is determined by the base station 2, this base station 2 sets the emergency information channel information AS a part of broadcast information and delivers this broadcast information in advance to the mobile terminals 1 existing within :the cell thereof and being under the control thereof by using, for example, the P-CCPCH. In this case, each of the mobile terminals 1 can start receiving the emergency information channel included in the MTCH according to the emergency information channel information delivered thereto in advance. [0192] When starting receiving the emergency information channel, the mobile terminal 1 notifies the user that it has started receiving the emergency information with a sound, vibrations, or a display of characters on the screen thereof (step STlSd) . For example, even when the mobile terminal is performing either a phone call or packet communications, the control unit 33 makes such a notification as mentioned above of emergency information by controlling a not-shown audio output unit, vibration mechanism, or display processing unit as the mobile terminal starts receiving the emergency information channel.' ;- In above-mentioned Embodiment 5, the case in which the mobile terminal is placed in an idle state (Idle state) is shown, though this method can ai*''** applied to a CELL_PCH state and a URA_PCH state because the method uses the PICH. [0193] As mentioned above, because the emergency information flag (emergency information indicator) showing the presence or absence of emergency information is disposed in the BCCH according to this Embodiment 5, the mobile communications system can notify the occurrence of emergency information to even a mobile terminal placed in an idle state in which it is not receiving any MBMS data via the BCCH to enable the mobile terminal to receive an emergency information channel included in an MBMS. Like in the case of above-mentioned Embodiment 4, because even a mobile terminal 1 which does not support the MBMS can receive the BCCH, each base station 2 can notify the presence or absence of emergency information to all the mobile terminals 1 existing within the cell thereof. In above-mentioned Embodiments 4 and 5, each base station 2 adds infonnation (emergency information channel information) required for mobile terminals 1 to receive the emergency information channel to the MCCH, and then maps emergency information to the emergency information channel included in the MTCH. Each base station control apparatus 3 can alternatively carry out these processes. Also in this case, the present embodiment offers an advantage of being able to enable each of a plurality of base stations 2 to transmit so-called wide area emergency information having the same description without carrying out the above-mentioned processes, thereby enabling a mobile tertninal existing at- an-end of a cell to combine the received powers from the above-mentioned plurality of base stations 2. As a result, the quality of reception of the emergency information of the mobile terminal can .-be improved, and the emergency information can be transmitted correctly and quickly to the mobile terminal. [0194] In above-mentioned Embodiment 4, information (BCCH Modify information) showing that the description of the BCCH has been changed is added to iAGING TYPE2 included in the DCCH, whereas in above-mentioned Embodiment 5, information (BCCH Modify information) showing that the description of the BCCH has been changed is added to PAGING TYPEl included in the PCCH. As an alternative, in addition to the information showing that the description of the BCCH has been changed, either information showing that there is emergency information or emergency information can be added. As the information showing that there is emergency information, information showing that emergency information is included in the MCCH or/and information showing that emergency information is included in the BCCH can be provided. By providing such the information, each mobile terminal can determine the presence or absence of the emergency information quickly, and the control delay caused by the notification of the emergency information can be reduced. Therefore, thre is provided an advantage of being able to reduce the time required for each mobile terminal to receive the emergency information. [0195] Furtheorraore, in . above-mentioned Erftbodiment 4, information (BCCH Modify>"information) showing that the description of the BCCH has 'Seen changed is adde«rtSb PAGING TYPE2 included in the DCCH, whereas in above-mentioned Embodiment 5, information (BCCH Modify information) showing that the de»C3rtp**on of the BCCH has been changed is added to PAGING TYPEl included in the PCCH, though instead of the information showing that the description of the BCCH has been changed, information showing that the description of the MCCH has been changed can By adding this information, each mobile terminal can receive the MCCH immediately without receiving the BCCH, and can therefore receive the emergency information channel according to the information regarding the emergency information channel included in the MCCH. Therefore, each mobile terminal can determine the presence or absence of the emergency information at an earlier time, and the control delay caused by the notification of the emergency information can be reduced. Therefore, there is provided an advantage of being able to reduce the time required for each mobile terminal to receive the emergency information. [0196] In any of above-mentioned Embodiments 1 to 5, the case in which the shown emergency information flag is one bit of data is described expressly, though the emergency information flag can be any data as long as it has only to show the presence or absence of emergency information. Furthermore, each mobile terminal 1 can be constructed in such a way as to, when there is emergency information, determine that there is emergency information. In the oase in which the emergency information flag is formed as mentioned above, the mobile communications system can notify not only the presence or absence of emergency information, but also information such as the type of the.description of the emergency information or the place where the emergency has occurred to each mobile terminal. [0197] As shown in above-mentioned Embodiments 1 to 5, in accordance with the present invention, each base station 2 can notify all the mobile terminals 1 existing within the cell thereof that an emergency has occurred, and can pass the emergency information in a broadcast type multimedia service to enable all the mobile terminals 1 which support the MBMS to automatically connect with the emergency information channel regardless of their" states. Therefore, the mobile communications system can notify the emergency information to many unspecified users without imposing any excessive load on the mobile communications network, without adding any special hardware to each mobile terminal 1, and without impairing the immediacy of the emergency information. [0198] In the above-mentioned explanation, the case in which an MBMS which is a broadcast type multimedia seirvice in the 3GPP is used is shown. The present invention is not limited to the case of using an MBMS, and can be applied to any case of using a broadcast type multimedia service for broadcasting a large amount of data by using a mobile communications network. [0139] The above-mentioned examples are based on a W-CDMA method, though the present invention can also be applied to the notification of emergency information using another communications method. ' For example, the present invention can also be applied to LTE "(Long Term Evolution LTE) , CDMA2000, and IxEV-DO described in the Background of the Invention. Industrial Applicability [02aai As mentioned above, a mobile communications system, a base station, and a mobile terminal in accordance with the present invention are constructed in such a way that in the mobile communications system including a mobile terminal and a base station which relays communications between a network and the mobile terminal, in which the base station can deliver information to the mobile terminal by using a broadcast type multimedia service, the base station sets a flag indicating the presence or absence of emergency information to a control channel used for the broadcast type multimedia service, and notifies the presence or absence of the emergency information to the mobile terminal by using the description of the flag set to the control channel. Therefore, the mobile communications system, the base station, and the mobile terminal in accordance with the present invention are suitable for use as a mobile communications system which notifies emergency information, and a base station and a mobile terminal in the mobile communications system, respectively. Claims [1] A mobile communications system including a plurality of mobile terminals and a base station, in which the base station can deliver emergency information to the plurality of mobile terminals, characterized in that: the base station transmi1:s an emergency information indicator showing presence of the emergency information to a plurality of mobile terminals including a mobile terminal which is receiving individual data and a mobile terminal which is being in an idle state by using paging messages, and transmits information required for the plurality of mobile terminals to receive the emergency information, and delivers the emergency information which can be received by the plurality of mobile terminals according to the information required for the plurality of mobile terminals to receive the emergency information; the mobile terminal which is being in an idle state included in the plurality of the mobile terminals receives the emergency information indicator showing presence of the emergency information, transmitted from the base station by the paging message, receives the information required for the plurality of mobile terminals to receive-■'the emergency information "transmitted from the base station, starts receiving the emergency information delivered from the base station according to the information required for the plurality of mobile terminals to receive the emergency information after receiving the emergency information indicator; and the mobile terminal which is receiving individual data included in the plurality of the mobile terminals receives the emergency information indicator showing presence of the emergency information, transmitted from the base station by the paging message, receives the d-nformation required for the plurality of mobile terminals to receive the emergency information transmitted from the base station, starts receiving the emergency information delivered from the base station according to the information required for the plurality of mobile terminals to receive the emergency information after receiving the emergency information indicator. [2] The mobile communications system according to claim 1, characterized in that the information required for the plurality of mobile terminals to receive the emergency information is emergency information channel number which is used to receive the emergency information by the mobile terminals. [3] The mobile communications system according to claim 1, characterized in that the mobile communications system is applied to Long Term Evolution. [4] The mobile communications system according to claim 1, characterized in that the paging message includes a field set the emergency information indicator showing presence of the emergency information.