JP2012205218A - Communication device, mobile terminal and data communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relaying device, a mobile terminal, and a data communication method that enable communications by user data with certainty when communications through respective traffic channels are congested in the event of an emergency, a disaster or the like.SOLUTION: A data communication method is for transmitting user data between a mobile device and a relaying device, placed on a wireless access network, for performing radio resource control over a communication with the mobile terminal. For example, a mobile terminal UE divides user data by predetermined data volume that can be accommodated in a RRC message, and creates a plurality of RRC messages, each including the predetermined volume of user data, to transmit the created data to a relaying device RN. The relaying device RN receives the plurality of RRC messages from the mobile terminal UE and retrieves the predetermined volume date from each of the received plurality of RRC messages and combines them.

Description

  The present invention relates to a technique for transmitting / receiving user data in a radio access network.

  There is already a dedicated communication line for monitoring the hazardous area in the event of an emergency or disaster. However, if the line is broken due to an earthquake or the like, the dangerous area cannot be monitored. For this reason, there is a high possibility of depending on wireless communication in the event of an emergency or disaster. At this time, for example, when a disaster occurs, many users try to perform wireless communication with the mobile terminal, and traffic congestion causes it to be difficult to send and receive normal mail and make calls. There are cases where it doesn't work. This is because as a result of many users trying to communicate at the same time, a dedicated traffic channel (DTCH: Dedicated Traffic Channel) necessary for transmission / reception of user data is insufficient.

  From this point of view, there is a data transmission method in which transmission priority is determined according to the service type in view of the fact that user data (for example, mail data) with low priority is difficult to be transmitted in the event of an emergency or disaster. Are known. According to this known data transmission method, a service set in a header of a packet in which transmission data is stored in an RLC (Radio Link Control) layer or a packet data convergence protocol (PDCP) sublayer of a mobile terminal Detect type information. Then, the service type of each transmission data set in the upper layer is detected in these layers, and the allocation priority of the uplink bandwidth in the lower layer MAC (Media Access Control) layer is determined according to the detected service type To do.

JP 2009-303030 A

  By the way, in the conventional data transmission method described above, the possibility that data assigned with a high priority will be transmitted is high, but the priority is high when communication by an individual traffic channel is congested such as in an emergency or disaster. Even data is not always transmitted.

  Therefore, in one aspect of the invention, a communication device, a mobile terminal, and a data communication method that enable more reliable communication using user data when communication using an individual traffic channel is congested, such as in an emergency or disaster The purpose is to provide.

In a first aspect, there is provided a communication device that is arranged on a radio access network and performs radio resource control in communication with a mobile terminal.
This communication device
A first data processing unit that divides user data to be transmitted to the mobile terminal into a plurality of data for each predetermined amount of data that can be accommodated in the radio resource control message;
A first transmission unit for accommodating each of the plurality of data in a radio resource control message and transmitting the data to a mobile terminal;
A first receiver that receives a plurality of radio resource control messages from a mobile terminal;
A second data processing unit that extracts and combines the predetermined amount of data from each of a plurality of radio resource control messages received by the first receiving unit;
Is provided.

In a second aspect, there is provided a mobile terminal that communicates with a communication device that is arranged on a radio access network and performs radio resource control.
This mobile terminal
A third data processing unit that divides user data to be transmitted to the communication device into a plurality of data for each predetermined amount of data that can be accommodated in the radio resource control message;
A second transmission unit for accommodating each of the plurality of data in a radio resource control message and transmitting the data to the communication device;
A second receiver for receiving a plurality of radio resource control messages from the communication device;
A fourth data processing unit that extracts and combines the predetermined amount of data from each of the plurality of radio resource control messages received by the second receiving unit;
Is provided.

In the third aspect, one of the mobile terminal and the communication apparatus that is arranged on the radio access network and performs radio resource control in communication with the mobile terminal is a transmission apparatus and the other is a reception apparatus. Thus, a data communication method for performing user data communication is provided.
This data communication method is
The transmission device divides user data for each predetermined amount of data that can be accommodated in the radio resource control message,
The transmitting device generates a plurality of radio resource control messages each including the predetermined amount of user data and transmits the messages to the receiving device,
The receiving device receives the plurality of radio resource control messages from the transmitting device,
The receiving device extracts and combines the predetermined amount of data from each of the plurality of received radio resource control messages.
Including that.

  According to the disclosed communication device, mobile terminal, and data communication method, communication using user data can be performed more reliably when communication using an individual traffic channel is congested such as in an emergency or disaster.

The figure which shows the radio | wireless communications system of embodiment. The figure which shows the protocol stack of the control plane of embodiment. The block diagram which shows the structure of the principal part of the base station of embodiment. The block diagram which shows the structure of the principal part of the mobile terminal of embodiment. The functional block diagram of the base station and mobile terminal of embodiment. The sequence diagram when a mobile terminal transmits user data in the radio | wireless communications system of embodiment. The sequence diagram when a mobile terminal receives user data in the radio | wireless communications system of embodiment.

(1) Wireless Communication System of Embodiment First, a wireless communication system of an embodiment will be described with reference to FIG.
As shown in FIG. 1, the wireless communication system of the embodiment shows an example in which a cell of a base station eNB is divided into several areas, and an RRH (Remote Radio Head) that performs wireless processing is arranged in each area. . The base station eNB shown in FIG. 1 has seven RRH-1, RRH-2,..., RRH-7, a relay device RN connected to each RRH and an optical cable (shown by a dotted line in FIG. 1), and storage. Includes server DS. The relay device RN mainly performs baseband processing. The optical cable between each RRH and the relay device RN may be separated by about 10 km, for example. For communication between each RRH and the relay apparatus RN, for example, a general-purpose interface such as OBSAI (Open Base Station Architecture Initiative) or CPRI (Common Public Radio Interface) may be used.
The base station eNB is an example of a communication device.

  As an example, the radio communication system of the present embodiment assumes a system in an E-UTRAN (Evolved UMTS Terrestrial Radio Access Network) that is a radio access network in LTE (Long Term Evolution). In E-UTRAN, unlike a UMTS (Universal Mobile Telecommunications System), a base station eNB has functions of RRC (Radio Resource Control) and RLC (Radio Link Control). Above the base station eNB, there is an MME (Mobility Management Entity) that performs control plane processing.

  When the mobile terminal UE in the cell performs communication via the base station eNB in the wireless communication system shown in FIG. 1, in an emergency or disaster situation, on the radio access network side higher than the base station eNB Informs that the general communication is restricted. Under such circumstances, a dedicated traffic channel (DTCH) cannot be secured, but there is a high possibility that traffic through the dedicated control channel (DCCH) can be communicated. The dedicated control channel is a channel used for transmission and reception of RRC messages between the mobile terminal UE and the base station eNB. In the present embodiment, user data is accommodated in the RRC message, so that user data can be transmitted / received even in an emergency or a disaster situation.

  In this embodiment, “UL (DL) INFORMATION TRANSFER” of the RRC message is used in order to accommodate the user data in the RRC message under an emergency or disaster situation. FIG. 2 shows the protocol stack of the control plane. Here, in a wireless communication system such as LTE, an NAS (Non-Access Stratum) message is included in a protocol higher than RRC. However, in the present embodiment, NAS is used in an emergency or disaster situation. Instead of the message, user data is inserted on the transmission side (base station eNB or mobile terminal UE).

  Further, in the present embodiment, it is determined by the relay device RN whether the protocol data higher than the RRC includes any data of NAS messages (for example, normal times) or user data (emergency or disaster). The IE (Information Element) for enabling this is defined as follows. That is, “dedicated Info U” is newly provided as the value of “dedicated Info Type” that is an IE in “UL (DL) INFORMATION TRANSFER” that is an RRC message. As for “UL (DL) INFORMATION TRANSFER”, for example, “3GPP TS 36.331 V9.4.0 (2010-09) 3rd Generation Partnership Project; Technical Specification Group Radio Access Network, which is a 3GPP (3rd Generation Partnership Project) standard specification. Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification (Release 9) ”.

When the relay apparatus RN receives “UL (DL) INFORMATION TRANSFER” as the RRC message, the relay apparatus RN checks the value of “dedicated Info Type” which is the IE in the RRC message. If the value of the “dedicated Info Type” of the received RRC message is “dedicated Info NAS”, the relay device RN sends the RRC message to the MME or the mobile terminal UE without confirming the content (NAS message) of this message. Forward. When the value of “dedicated Info Type” in the received RRC message is “dedicated Info U”, the relay device RN determines that user data is included in the received RRC message.
When including the user data in the RRC message to be transmitted, the relay apparatus RN sets the value of “dedicated Info Type” of the RRC message to be transmitted to “dedicated Info U”.

  Here, the amount of user data that can be accommodated by one RRC message is small. Therefore, between the relay device RN and the mobile terminal UE, the user data that should originally be transmitted is divided into a plurality of predetermined amounts of data for transmission. At this time, on the transmitting side, the RRC message is transmitted after a predetermined amount of data is included in each of the plurality of RRC messages in which the value of “dedicated Info Type” is set to “dedicated Info U”. To do. On the receiving side, the value of “dedicated Info Type” of the received RRC message is confirmed, and it is checked whether individual data obtained by dividing user data is included. On the receiving side, the original user data is generated by combining a plurality of predetermined data included in the plurality of RRC messages in association with the same connection ID.

  More specifically, when transmitting user data from the mobile terminal UE to the MME, the relay device RN extracts the divided user data from each of a plurality of RRC messages received from the mobile terminal UE and stores the user data. Forward to. The storage server DN confirms that all divided user data (a predetermined amount of data) has been received in connection ID units, combines the divided user data, combines the original user data, and combines the MME. Send to. Conversely, when transmitting user data from the MME to the mobile terminal UE, the storage server DN divides the user data received from the MME, and the relay device RN transmits the divided user data (a predetermined amount of data) to a plurality of RRC messages. Are transmitted to the mobile terminal UE.

(2) Configurations of Base Station eNB and Mobile Terminal UE Next, configurations of the base station eNB and the mobile terminal UE of the present embodiment will be described with reference to FIG. 3 and FIG. FIG. 3 is a block diagram illustrating a configuration of a main part of the base station eNB of the present embodiment. FIG. 4 is a block diagram illustrating a configuration of a main part of the mobile terminal UE of the present embodiment. The configuration of FIG. 3 is an example applied to the system shown in FIG.

First, referring to FIG. 3, the base station eNB of the present embodiment includes a plurality of RRHs RRH-1, RRH-2,..., RRH-7 provided for each area, and a relay device RN.
The RRH includes a transmission antenna and a reception antenna (both antennas may be shared by providing a duplexer), a radio transmission unit, and a radio reception unit (both not shown).
The wireless transmission unit includes a D / A (Digital to Analog) converter, a local frequency transmitter, a mixer, a power amplifier, a filter, and the like. The radio transmission unit radiates the transmission signal (baseband signal) addressed to the mobile terminal UE received from the relay device RN from the transmission antenna to the space after up-converting from the baseband frequency to the radio frequency.
The radio reception unit includes a band limiting filter, a low noise amplifier (LNA), a local frequency oscillator, a quadrature demodulator, an AGC (Automatic Gain Control) amplifier, an A / D (Analog to Digital) converter, and the like. The radio reception unit converts a radio signal received from the mobile terminal UE at the reception antenna into a digital baseband signal, and transmits the baseband signal to the relay device RN.

The relay device RN includes a plurality of baseband units BBU (Base Band Units) BBU-1, BBU-2,..., BBU-7 corresponding to each RRH, an L2 switch 10, and a network I / F (Interface). 20, a control unit 30, and a memory 31.
When each baseband unit BBU receives a baseband signal from the corresponding RRH, it performs demodulation processing of the baseband signal and decoding processing (decoding) of error correction, and then the received signal after processing is switched to the L2 switch. To send. When each baseband unit BBU transmits a baseband signal to each RRH, the baseband transmission signal provided from the L2 switch 10 is subjected to error correction encoding processing (encoding) and modulation processing. Thereafter, the processed transmission signal is sent to each RRH.

  The L2 switch 10 functions as a layer 2 switch between each baseband unit BBU and the network I / F 20. The L2 switch 10 distributes and transfers the signal received from the MME via the network I / F 20 for each baseband unit BBU corresponding to the destination mobile terminal UE. In addition, the L2 switch 10 sequentially sends the signals received from the baseband units BBU to the network I / F 20.

The network I / F 20 includes a circuit for exchanging signals with the MME and the S1 interface, or with another base station eNB and the X2 interface.
The control unit 30 is configured mainly with a microcontroller, and performs signal control corresponding to the control channel while using a memory 31 configured as, for example, a RAM (Random Access Memory) and / or a ROM (Read Only Memory). For example, the control unit 30 receives a dedicated control channel (DCCH) signal from the network I / F 20 and performs control according to the content. The functions executed by the control unit 30 and the memory 31 will be described later.

Next, referring to FIG. 4, the mobile terminal UE of the present embodiment includes an antenna 44, a radio processing unit 45, a modem unit 46, an encoding / decoding unit 47, a control unit 50, and an application processing unit 60. And memories 51 and 61.
The wireless processing unit 45 includes a wireless transmission unit and a wireless reception unit (both not shown), and includes an analog circuit and a digital circuit.
The wireless transmission unit includes a D / A converter, a local frequency transmitter, a mixer, a power amplifier, a filter, and the like. The radio transmission unit radiates the transmission signal (baseband signal) addressed to the base station eNB from the modulation / demodulation unit 46 from the antenna 44 to the space after up-converting the baseband frequency to the radio frequency.
The wireless reception unit includes a band limiting filter, a low noise amplifier, a local frequency transmitter, a quadrature demodulator, an AGC amplifier, an A / D converter, and the like. The radio reception unit converts the radio signal received from the base station eNB (RRH) at the antenna 44 into a digital baseband signal, and sends the baseband signal to the modem unit 46.

The modulation / demodulation unit 46 performs demodulation processing on the reception signal transmitted from the wireless processing unit 45 at the time of signal reception, and performs modulation processing (decoding) on the transmission signal transmitted from the encoding / decoding unit 47 at the time of signal transmission. I do. The encoding / decoding unit 47 performs a decoding process on the reception signal transmitted from the modulation / demodulation unit 46 at the time of signal reception, and encodes (encodes) the transmission signal transmitted from the control unit 50 at the time of signal transmission. I do.
The modem unit 46 and the encoding / decoding unit 47 can be realized by a digital circuit such as a DSP (Digital Signal Processor).

The control unit 50 is configured mainly with a microcontroller, and performs signal control according to the control channel (DCCH) and the user data dedicated channel (DTCH) while using the memory 51 configured as a RAM and / or a ROM. The functions executed by the control unit 50 and the memory 51 will be described later.
The application processing unit 60 is configured mainly with a microcontroller (may be shared with the control unit 50), and uses a memory 61 configured as a RAM and / or a ROM, for example, a user received from the base station eNB. A predetermined application program is executed based on the data.

(3) Functional Block and Sequence of Base Station eNB and Mobile Terminal UE Next, main functions realized by the base station eNB and the mobile terminal UE will be described with reference to the functional block diagram shown in FIG.

  As illustrated in FIG. 5, the mobile terminal UE includes a functional block group 500 including functional blocks of an RRC receiving unit 501, an RRC determining unit 502, an RRC transmitting unit 503, a data processing unit 504, and an RRC creating unit 505. Each functional block of the functional block group 500 is mainly realized by the encoding / decoding unit 47 and the control unit 50.

The RRC receiving unit 501 is a functional block that receives and decodes the RRC message from the relay device RN.
The RRC determination unit 502 is a functional block that determines whether the received RRC message is broadcast information including a load restriction (release) notification and determines whether a part of user data is included in the received RRC message.
The RRC transmission unit 503 is a functional block that encodes an RRC message created in its own device and transmits it to the relay device RN.
When transmitting user data from its own terminal, the data processing unit 504 divides the user data into a predetermined amount of data according to the transmission mode, and receives user data for the own terminal according to the transmission mode. It is a functional block for combining user data that is divided into fixed amounts.
The RRC creation unit 505 is a functional block that creates an RRC message after setting an IE (Information Element) value.

  As shown in FIG. 5, the relay device RN includes an RRC reception unit 301, an RRC determination unit 302, an MSG transmission unit 303, an S1 creation unit 304, an RRC creation unit 305, a data reception unit 306, a data creation unit 307, and an S1 reception. A functional block group 300 including each functional block of the unit 308 is provided. Each functional block of the functional block group 300 is mainly realized by the baseband processing unit BBU and the control unit 30.

The RRC receiving unit 301 is a functional block that receives and decodes an RRC message from the mobile terminal UE.
The RRC determination unit 302 is a functional block that determines whether a part of user data is included in the received RRC message.
The MSG transmission unit 303 is a functional block that encodes a message created in its own device and transmits it to another node.
The S1 creation unit 304 is a functional block that creates an S1 message after setting an IE.
The RRC creation unit 305 is a functional block that creates an RRC message to be transmitted to the mobile terminal UE based on the received message.
The data receiving unit 306 is a functional block that receives and decodes data from the storage server DS.
The data creation unit 307 is a functional block that creates a message for transmitting user data to the storage server DS.
The S1 receiving unit 308 is a functional block that receives and decodes the S1 message transmitted from the MME.

  As illustrated in FIG. 5, the storage server DS includes functional blocks of a data reception unit 701, a data processing unit 702, and an MSG transmission unit 703. In addition, the storage server DS includes a connection ID table memory 704 and a data memory 705. In the storage server DS, for example, each functional block is realized by a microcontroller, a memory such as a RAM and / or a ROM, and a transmission / reception unit using a digital circuit.

The data receiving unit 701 is a functional block that receives and decodes the RRC message from the relay device RN or MME.
The data processing unit 702 performs processing for combining data from the relay device RN when transmitting user data of the mobile terminal UE to the MME, and processing for dividing user data when transmitting user data from the MME to the mobile terminal UE. It is a functional block diagram performed in connection ID unit.
The MSG transmission unit 703 is a functional block that encodes an RRC message created in its own device and transmits it to the relay device RN or MME.
The connection ID table memory 704 is a storage device for associating user data to be processed with a connection ID.
The data memory 705 is a storage device that temporarily stores data to be transmitted or combined.

(4) Sequence of base station eNB and mobile terminal UE Next, referring to FIG. 6 and FIG. 7, a sequence when user data is inserted into an RRC message and transmitted or received between the mobile terminal UE and the MME. explain. FIG. 6 shows a sequence when the mobile terminal UE transmits user data, and FIG. 7 shows a sequence when the mobile terminal UE receives user data.

(4-1) Data transmission sequence First, a sequence when the mobile terminal UE transmits user data will be described.
In the event of an emergency or disaster, first, the RRC receiving unit 501 of the mobile terminal UE receives and decodes notification information (load regulation) transmitted from the network (MME) through the relay device RN (step S10). The RRC reception unit 501 sends the decoded notification information to the RRC determination unit 502. When the received RRC message is broadcast information including a load regulation notification, the RRC determination unit 502 turns on a load regulation flag (ON: valid, OFF: invalid) for managing whether to regulate the load regulation. (Step S20).

  When user data to be transmitted is generated, the data processing unit 504 of the mobile terminal UE issues a data transmission request to the RRC creation unit 505. User data to be transmitted is held in the data processing unit 504. When the RRC creation unit 505 receives a data transmission request, the RRC creation unit 505 first refers to the load restriction flag, and transmits a transmission method (hereinafter referred to as “divided transmission mode”) in which user data is divided into a plurality of data transmissions. Determine whether to use. If the load restriction flag is ON, the RRC creation unit 505 determines to use the divided transmission mode.

  The RRC creation unit 505 creates an RRC CONNECTION REQUEST message to establish a connection for data transmission and sends it to the RRC transmission unit 503. However, when the load restriction flag is ON, the fact that the split transmission mode is used is included in the RRC CONNECTION REQUEST. The RRC transmission unit 503 encodes the message sent from the RRC creation unit 505 and transmits it to the relay device RN (step S30). 6 and 7, a signal including “divided transmission” in parentheses, such as RRC CONNECTION REQUEST (divided transmission), means that information indicating that the divided transmission mode is used is included.

The RRC reception unit 301 of the relay device RN receives and decodes the RRC CONNECTION REQUEST message transmitted from the mobile terminal UE. The RRC reception unit 301 sends the decoded message to the RRC determination unit 302. When the received RRC message does not include user data, the RRC determination unit 302 passes the decoded message to the RRC creation unit 305. When the received RRC message is RRC CONNECTION REQUEST (divided transmission), the RRC determination unit 302 sets a divided transmission flag (ON: enabled, OFF: disabled) for managing whether to enable the divided transmission mode. Turn on (step S40). The divided transmission flag is managed for each connection ID.
When receiving RRC CONNECTION REQUEST (divided transmission), the RRC creation unit 305 sets the radio bearer (SRB1) of the dedicated control channel (DCCH), and issues a transmission request for RRC CONNECTION SETUP to the MSG transmission unit 303 To do. The RRC creation unit 305 holds that the connection related to the transmission request is in the divided transmission mode. The MSG transmission unit 303 encodes the RRC CONNECTION SETUP received from the RRC creation unit 305 and transmits it to the mobile terminal UE (step S50).

  The RRC reception unit 501 of the mobile terminal UE receives and decodes the RRC CONNECTION SETUP transmitted by the relay device RN, and sends the decoded message to the RRC determination unit 502. The RRC determination unit 502 confirms that user data is not included in the received message and that this message is not broadcast information, and sends the decoded data to the RRC creation unit 505. The RRC creation unit 505 creates RRC CONNECTION SETUP COMPLETE and issues a message transmission request to the RRC transmission unit 503. The RRC transmission unit 503 encodes the RRC CONNECTION SETUP COMPLETE sent from the RRC creation unit 503 and transmits it to the relay device RN (step S60).

  The RRC reception unit 301 of the relay device RN receives the RRC CONNECTION SETUP COMPLETE transmitted from the mobile terminal UE, decodes the received RRC CONNECTION SETUP COMPLETE, and sends it to the RRC determination unit 302. The RRC determination unit 302 confirms that user data is not included in the received message (RRC CONNECTION SETUP COMPLETE), and sends the message to the RRC creation unit 305. The RRC creation unit 305 notifies the S1 creation unit 304 that RRC CONNECTION SETUP COMPLETE has been received. Upon receiving the RRC CONNECTION SETUP COMPLETE reception notification, the S1 creation unit 304 creates INITIAL UE MESSAGE and issues a transmission request to the MSG transmission unit 303 together with the message. The MSG transmission unit 303 decodes the message received from the S1 creation unit 304 and transmits it to the MME (step S70).

  In response to the INITIAL UE MESSAGE transmitted from the relay device RN, the MME transmits INITIAL CONTEXT SETUP to the relay device RN (step S80). The S1 receiving unit 308 of the relay device RN decodes the INITIAL CONTEXT SETUP received from the MME and sends the message to the S1 creating unit 304. The S1 creation unit 304 notifies the RRC creation unit 305 of the reception of INITIAL CONTEXT SETUP. Upon receiving the INITIAL CONTEXT SETUP reception notification from the S1 creation unit 304, the RRC creation unit 305 creates a SECURITY MODE COMMAND, transmits the message to the MSG transmission unit 303, and issues a transmission request to the MSG transmission unit 303. The MSG transmission unit 303 encodes the SECURITY MODE COMMAND received from the RRC creation unit 305 and transmits it to the mobile terminal UE (step S90).

  The RRC receiving unit 501 of the mobile terminal UE receives and decodes the SECURITY MODE COMMAND transmitted by the relay device RN. The RRC reception unit 501 sends the decoded message to the RRC determination unit 502. The RRC determination unit 502 confirms that user data is not included in the received message (SECURITY MODE COMMAND) and that this message is not broadcast information, and passes the decoded message to the RRC creation unit 505. The RRC creation unit 505 creates SECURITY MODE COMPLETE and issues a transmission request for the message to the RRC transmission unit 503. The RRC transmission unit 503 encodes the SECURITY MODE COMPLETE received from the RRC creation unit 505 and transmits it to the relay device RN (step S100).

The RRC reception unit 301 of the relay device RN receives the SECURITY MODE COMPLETE transmitted from the mobile terminal UE, decodes it, and sends it to the RRC determination unit 302. The RRC determination unit 302 confirms that user data is not included in the received message (SECURITY MODE COMPLETE), and passes the message to the RRC creation unit 305. The RRC creation unit 305 confirms that the split transmission mode of this connection is ON, and returns a SECURITY MODE COMPLETE reception notification confirmation (split transmission) to the S1 creation unit 304. This reception notification confirmation (divided transmission) includes the reception notification confirmation message indicating that it is in the divided transmission mode. When the divided transmission mode is OFF, that is, in the case of a normal connection, RRC CONNECTION RECONFIGURATION addressed to the mobile terminal UE is created.
The S1 creation unit 304 receives the SECURITY MODE COMPLETE reception notification confirmation (divided transmission) from the RRC creation unit 305, and creates an INITIAL CONTEXT SETUP RESPONSE (divided transmission). The MSG transmission unit 303 encodes the INITIAL CONTEXT SETUP RESPONSE (divided transmission) received from the S1 creation unit 304 and transmits it to the MME (step S110).
As described above, preparation for divided transmission of user data is completed.

When the preparation for split transmission of user data is completed, the mobile terminal UE performs the following data split processing (step S120). That is, the RRC creation unit 505 of the mobile terminal UE issues a data request to the data processing unit 504 to notify the completion of preparation for data transmission and the amount of data that can be transmitted. The data processing unit 504 divides the held user data into data of the notified data amount (predetermined amount of data), assigns data numbers in order, and passes them to the RRC creation unit 505.
The RRC creation unit 505 creates a UL INFORMATION TRANSFER (dedicated Info Type = dedicated Info U), which is an RRC message containing a predetermined amount of data passed from the data processing unit 504, and sends it to the RRC transmission unit 503. A transmission request is issued to the transmission unit 503. The RRC transmission unit 503 encodes the message (UL INFORMATION TRANSFER) received from the RRC creation unit 505 and transmits it to the relay device RN (step S130).

Next, the relay device RN makes a data storage request to the storage server DS (step S140). This process is performed for a plurality of pieces of data (from the first data (data number n = 1) to the last data (data number n = end) divided by connection unit (connection ID unit). The data storage request includes the following processing.
First, the RRC reception unit 301 of the relay device RN receives an RRC message (UL INFORMATION TRANSFER) transmitted from the mobile terminal UE, decodes it, and sends it to the RRC determination unit 302. When a part of user data is included in the received RRC message, the RRC determination unit 302 extracts the data and sends it to the data creation unit 307. The data creation unit 307 creates a message addressed to the storage server DS including the data sent from the RRC determination unit 302, sends the message to the MSG transmission unit 303, and issues a transmission request to the MSG transmission unit 303. . The MSG transmission unit 303 encodes the message received from the data creation unit 307 and transmits it to the storage server DS.

The data receiving unit 701 of the storage server DS decodes the message (data storage request) received from the relay device RN and sends it to the data processing unit 702. The data processing unit 702 refers to the connection ID table memory 704 and newly registers it in the connection ID table (CID table) if the connection ID of the received message is not registered (step S150). The data processing unit 702 writes and holds the received data together with the connection ID and data number in the data memory 705 (step S160).
When the data processing unit 702 repeats the processing of steps S140 to S160 for each of the plurality of divided data and recognizes the last data (data number n = end), it combines the data accumulated so far. Process. Further, the data processing unit 702 creates a message including the user data obtained by combining and sends it to the MSG transmission unit 703. The MSG transmission unit 703 encodes the message sent from the data processing unit 702 and transmits it to the MME.

(4-2) Data reception sequence Next, a sequence when the mobile terminal UE receives user data will be described.
Since the process when the mobile terminal UE receives user data has many processes common to the data transmission process described with reference to FIG. 6, the difference from the data transmission with reference to FIG. 7 is described below. I will focus on this point and explain. In addition, below, the case where a connection ID table and data are stored in the memory 51 of the mobile terminal UE will be described.
In FIG. 7, the mobile terminal UE receives, from the MME, a paging message (PAGING) indicating that there is downlink data destined for the own terminal through the relay device RN (step S25). A connection establishment procedure is started by using this paging message as a trigger. In this connection establishment procedure, the same processing as steps S30 to S110 at the time of data transmission is performed.

In the data reception procedure following the connection establishment procedure, first, the data reception unit 701 of the storage server DS receives a data transmission request including user data for each connection ID from the MME (step S200). The data processing unit 702 refers to the connection ID table memory 704 and newly registers it in the connection ID table (CID table) if the connection ID of the received data transmission request is not registered (step S210). The data processing unit 702 writes and holds the received user data in the data memory 705 together with the connection ID (step S220).
Next, the data processing unit 702 of the storage server DS performs data division processing (step S230). The data division process is a process of dividing the user data written in the data memory 705 in step S220 into a plurality of predetermined amounts of data that can be accommodated in the RRC message. The data processing unit 702 attaches a data number to each divided data in order and passes the data to the MSG transmission unit 703. The MSG transmission unit 703 sequentially transmits the data passed from the MSG transmission unit 703 to the relay device RN (step S240). At this time, each data is associated with the connection ID and the data number.

  The data receiving unit 306 of the relay device RN receives each of a plurality of data transmitted from the storage server DS, and passes each received data to the RRC creating unit 305. The RRC creation unit 305 creates a DL INFORMATION TRANSFER (dedicated Info Type = dedicated Info U) that is an RRC message containing the data received from the data reception unit 306, sends the message to the MSG transmission unit 303, and transmits the MSG A request for transmitting the message is issued to the unit 303. The MSG transmission unit 303 encodes the message (DL INFORMATION TRANSFER) received from the RRC creation unit 305 and transmits it to the mobile terminal UE (step S250).

  The RRC reception unit 501 of the mobile terminal UE decodes the RRC message received from the relay device RN and sends it to the RRC determination unit 502. The RRC determination unit 502 causes the data processing unit 504 to execute the following processing. That is, the data processing unit 504 refers to the memory 51 and newly registers it in the connection ID table (CID table) if the connection ID of the received message is not registered. The data processing unit 504 writes and holds the received data together with the connection ID and data number in the memory 51 (step S260). When the data processing unit 504 repeats the processing of step S260 for each of the plurality of divided data included in the received message and recognizes the last data (data number n = end), the data processing unit 504 has accumulated so far. The data is merged (step S270). When the data combination is completed, the mobile terminal UE transmits a data reception completion notification to the storage server DS through the relay device RN (step S280).

  As described above, according to the wireless communication system of the present embodiment, user data is divided into a predetermined amount of data and accommodated in a plurality of RRC messages in an emergency or disaster situation. As a result, user data can be reliably transmitted and received even in the event of an emergency or disaster.

  The embodiment of the present invention has been described in detail above. However, the communication device, mobile terminal, and data communication method of the present invention are not limited to the above embodiment, and various improvements and modifications can be made without departing from the gist of the present invention. Of course, you may do. For example, the wireless communication system of the above-described embodiment has a configuration corresponding to E-UTRAN, which is an LTE radio access network, and a base station (relay device, storage server) that performs Layer 3 (RRC) processing as a communication device. However, the present invention is not limited to this. For example, in UMTS, which is a W-CDMA (Wideband-Code Division Multiple Access) radio access network, layer 3 (RRC) processing is performed by an RNC (Radio Network Controller). Therefore, when the present invention is applied to UMTS, the RNC performs the functions of the relay device and the storage server. That is, the communication apparatus of the present invention can be realized as a part of the function of either the base station or the RNC.

  Regarding the above embodiments, the following additional notes are disclosed.

(Appendix 1)
A communication device arranged on a radio access network and performing radio resource control in communication with a mobile terminal,
A first data processing unit that divides user data to be transmitted to the mobile terminal into a plurality of data for each predetermined amount of data that can be accommodated in the radio resource control message;
A first transmission unit for accommodating each of the plurality of data in a radio resource control message and transmitting the data to a mobile terminal;
A first receiver that receives a plurality of radio resource control messages from a mobile terminal;
A second data processing unit that extracts and combines the predetermined amount of data from each of a plurality of radio resource control messages received by the first receiving unit;
A communication device comprising:

(Appendix 2)
The radio resource control message is a message that can set information about whether to have user data,
When the first transmission unit receives broadcast information for performing traffic load regulation by the first reception unit, the first transmission unit transmits a radio resource control message in which information indicating that user data is included is set to the mobile terminal,
The second data processing unit refers to the information in the radio resource control message received from the mobile terminal and determines whether to extract user data from the message;
The communication apparatus described in appendix 1.

(Appendix 3)
A mobile terminal that communicates with a communication device that is arranged on a radio access network and performs radio resource control,
A third data processing unit that divides user data to be transmitted to the communication device into a plurality of data for each predetermined amount of data that can be accommodated in the radio resource control message;
A second transmission unit for accommodating each of the plurality of data in a radio resource control message and transmitting the data to the communication device;
A second receiver for receiving a plurality of radio resource control messages from the communication device;
A fourth data processing unit that extracts and combines the predetermined amount of data from each of the plurality of radio resource control messages received by the second receiving unit;
Mobile terminal equipped with.

(Appendix 4)
The radio resource control message is a message that can set information about whether to have user data,
The second transmission unit transmits a radio resource control message in which information indicating that it has user data is set to the communication device when the second reception unit receives broadcast information for performing traffic load regulation,
The second data processing unit refers to the information in the radio resource control message received from the communication device and determines whether to extract user data from the message;
The mobile terminal described in Appendix 3.

(Appendix 5)
Between the mobile terminal and a communication device that is arranged on the radio access network and performs radio resource control in communication with the mobile terminal, one is a transmitting device and the other is a receiving device to communicate user data. A data communication method for performing
The transmission device divides user data for each predetermined amount of data that can be accommodated in the radio resource control message,
The transmitting device generates a plurality of radio resource control messages each including the predetermined amount of user data and transmits the messages to the receiving device,
The receiving device receives the plurality of radio resource control messages from the transmitting device,
The receiving device extracts and combines the predetermined amount of data from each of the plurality of received radio resource control messages.
A data communication method.

(Appendix 6)
When the transmitter receives broadcast information for traffic load regulation, the transmitter transmits information including user data in the radio resource control message,
When receiving the radio resource control message, the receiving device refers to the information to determine whether to extract user data from the received radio resource control message.
The data communication method described in appendix 5.

eNB ... Base station
RN ... Relay device 10 ... L2 switch 20 ... Network I / F
30 ... Control unit 31 ... Memory
DS ... Storage server
UE ... mobile terminal 44 ... antenna 45 ... wireless processing unit 46 ... modulation / demodulation unit 47 ... encoding / decoding unit 50 ... control unit 51 ... memory 60 ... application processing unit 61 ... memory

Claims (4)

A communication device arranged on a radio access network and performing radio resource control in communication with a mobile terminal,
A first data processing unit that divides user data to be transmitted to the mobile terminal into a plurality of data for each predetermined amount of data that can be accommodated in the radio resource control message;
A first transmission unit for accommodating each of the plurality of data in a radio resource control message and transmitting the data to a mobile terminal;
A first receiver that receives a plurality of radio resource control messages from a mobile terminal;
A second data processing unit that extracts and combines the predetermined amount of data from each of a plurality of radio resource control messages received by the first receiving unit;
A communication device comprising: The radio resource control message is a message that can set information about whether to have user data,
When the first transmission unit receives broadcast information for performing traffic load regulation by the first reception unit, the first transmission unit transmits a radio resource control message in which information indicating that user data is included is set to the mobile terminal,
The second data processing unit refers to the information in the radio resource control message received from the mobile terminal and determines whether to extract user data from the message;
The communication apparatus according to claim 1. A mobile terminal that communicates with a communication device that is arranged on a radio access network and performs radio resource control,
A third data processing unit that divides user data to be transmitted to the communication device into a plurality of data for each predetermined amount of data that can be accommodated in the radio resource control message;
A second transmission unit for accommodating each of the plurality of data in a radio resource control message and transmitting the data to the communication device;
A second receiver for receiving a plurality of radio resource control messages from the communication device;
A fourth data processing unit that extracts and combines the predetermined amount of data from each of the plurality of radio resource control messages received by the second receiving unit;
Mobile terminal equipped with. Between the mobile terminal and a communication device that is arranged on the radio access network and performs radio resource control in communication with the mobile terminal, one is a transmitting device and the other is a receiving device to communicate user data. A data communication method for performing
The transmission device divides user data for each predetermined amount of data that can be accommodated in the radio resource control message,
The transmitting device generates a plurality of radio resource control messages each including the predetermined amount of user data and transmits the messages to the receiving device,
The receiving device receives the plurality of radio resource control messages from the transmitting device,
The receiving device extracts and combines the predetermined amount of data from each of the plurality of received radio resource control messages.
A data communication method.

Images