JP4167267B2 - Mobile communication terminal and cell transition control method - Google Patents

Description

  The present invention relates to a mobile communication terminal and a cell transition control method in the mobile communication terminal.

  In a mobile communication network, the following processing is performed when a wireless connection is established between a mobile communication terminal and a base station. The mobile communication terminal transmits a radio connection request (RRC CONNECTION REQUEST) to the base station, and receives a response (RRC CONNECTION SETUP) transmitted from the base station in response to the radio connection request. Thereafter, the mobile communication terminal transmits a connection completion notification (RRC CONNECTION SETUP COMPLETE) to the base station in response to the response, thereby establishing a wireless connection. Normally, when there is no response from the base station, the wireless connection request is retransmitted a plurality of times.

In addition, when the mobile communication terminal detects the deterioration of the strength (reception level) of the radio wave from the base station with which it is communicating, which base station should it communicate with based on the strength of the radio wave from another base station, etc. Judgment is made, and the base station of the communication partner is switched, that is, cell transition (CELL RESELECTION) is performed (see, for example, Patent Document 1 below).
JP 2004-159304 A

  By the way, in a cell in a mobile communication network, a connection request restriction (for example, ACC (Access Class Control) restriction in 3GPP (3rd Generation Partnership Project)) prohibiting transmission of a wireless connection request is applied to a mobile communication terminal. Some are applicable. This connection request regulation is performed, for example, for the purpose of alleviating the congestion state of communication.

  There are the following problems related to such regulations. For example, after the mobile communication terminal transmits a wireless connection request, when the cell shifts to a cell to which the above connection request restriction is applied, the wireless connection request cannot be retransmitted in the cell after the cell shift. In such a case, the wireless connection between the mobile communication terminal and the base station is not established, and the mobile communication terminal waits for a response to the wireless connection request or waits for retransmission of the wireless connection request, and may enter a so-called deadlock state. is there. In addition, since a wireless connection between the mobile communication terminal and the base station cannot be established, a call or the like related to the wireless communication request becomes a call loss.

  The present invention has been made in order to solve the above-described problems, and it is possible to prevent a deadlock state during processing related to a wireless connection request and to establish a wireless connection despite the fact that a wireless connection can be established. An object of the present invention is to provide a mobile communication terminal and a cell transition control method capable of preventing a connection from being established and improving a connection rate.

To achieve the above object, a mobile communication terminal according to the present invention is a mobile communication terminal which performs a process relating to the radio connection request to the base station comprising a retransmission of the radio connection request to the base station, a wireless connection request Receiving broadcast information from a base station different from the target base station, and determining whether the radio field intensity related to the broadcast information from the other base station satisfies the cell transition condition, If it is determined that the cell transition condition is satisfied, it is determined whether or not a connection request restriction prohibiting transmission of a wireless connection request in the cell of the base station is applied to the terminal based on the received broadcast information. During the processing related to the wireless connection request started by transmission of the determination means and the wireless connection request , the connection request restriction is determined by the determination means in a cell different from the cell of the base station that is the target of the wireless connection request. Applicable to Once, characterized in that it comprises a control means for controlling to prohibit the cell migration to the different cells, a.

  In the mobile communication terminal according to the present invention, when it is determined that a connection request restriction prohibiting transmission of a wireless connection request in a cell that can become a cell transition destination is applied to the terminal during processing related to the wireless connection request. The cell transition is prohibited, and the cell transition to such a cell is not performed. Thereby, the mobile communication terminal can transmit a wireless connection request in a cell to which the connection request restriction is not applied. Therefore, according to the mobile communication terminal according to the present invention, it is possible to prevent a deadlock state during processing related to a wireless connection request and to establish a wireless connection even though the wireless connection can be established. Thus, the connection rate can be improved.

  By the way, the present invention can be described as an invention of a mobile communication terminal as described above, and can also be described as an invention of a cell transition control method in the mobile communication terminal as follows. This is substantially the same invention only in different categories, and has the same operations and effects.

That is, the cell transition control method according to the present invention is a cell change control method in a mobile communication terminal which performs a process related to the radio connection request to the base station that includes the retransmission of radio connection request to the base station, a wireless connection request Receiving broadcast information from a base station different from the target base station, and determining whether the radio field intensity related to the broadcast information from the other base station satisfies the cell transition condition, If it is determined that the cell transition condition is satisfied, it is determined whether or not a connection request restriction prohibiting transmission of a wireless connection request in the cell of the base station is applied to the terminal based on the received broadcast information. a judgment step, in the process according to the wireless connection request initiated by the transmission of the wireless connection request, in decision, a connection request regulation local end in another cell with a cell of a base station to be the wireless connection request If it is determined to be applied, characterized in that it comprises a control step for controlling to prohibit the cell migration to the different cells, a.

  In the present invention, during the process related to the wireless connection request, the cell transition to the cell to which the connection request restriction is applied is not performed, and the mobile communication terminal transmits the wireless connection request in the cell to which the connection request restriction is not applied. It can be carried out. Therefore, according to the present invention, it is possible to prevent a deadlock state during processing relating to a wireless connection request and to prevent a wireless connection from being established despite a situation in which the wireless connection can be established. Can be improved.

  Hereinafter, preferred embodiments of a mobile communication terminal and a cell transition control method according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 shows a configuration of a mobile communication terminal 10 according to the present embodiment. In the present embodiment, the mobile communication terminal 10 is a mobile phone that can perform mobile communication. The mobile communication terminal 10 is specifically configured by hardware such as a CPU (Central Processing Unit), a memory, and a mobile communication module such as an antenna, and will be described below by operating them. Each function of the mobile communication terminal 10 is exhibited. As shown in FIG. 1, the mobile communication terminal 10 includes a transmission / reception unit 11, a mobile phone function unit 12, a mobile communication function unit 13, a storage unit 14, a determination unit 15, and a control unit 16.

  The transmission / reception unit 11 is connected to an antenna and is means for transmitting / receiving radio waves for mobile communication. The transmission / reception unit 11 also performs conversion between communication data and radio waves.

  The mobile phone function unit 12 is connected to the transmission / reception unit 11 and serves as a mobile phone. For example, it is connected to hardware such as a microphone and a speaker, and voice input from the user is converted into communication data and transmitted to the transmission / reception unit 11, or communication data is received from the transmission / reception unit 11 and converted into voice. Output.

  The mobile communication function unit 13 is connected to the transmission / reception unit 11, the mobile phone function unit 12, and the storage unit 14, and is a means for executing the mobile communication function of the mobile communication terminal 10. In the mobile communication terminal 10, mobile communication functions controlled by the mobile communication function unit 13 include establishment of a wireless connection and cell transition.

  The establishment of the wireless connection is performed, for example, at the time of making a call for making a call or at the start of data communication, and is performed as follows. As shown in FIG. 2, first, the mobile communication function unit 13 sends a radio connection request (RRC CONNECTION REQUEST) to the base station 20 (generic name of the base stations 20a and 20b) constituting the mobile communication network via the transmission / reception unit 11. ) 31 is transmitted. The base station 20 that has received the wireless connection request 31 sends a response (RRC CONNECTION SETUP) 32 corresponding to the wireless connection request 31 to the mobile communication terminal 10 when wireless connection from the mobile communication terminal 10 is possible. Send. In the mobile communication terminal 10, the mobile communication function unit 13 receives the response 32 via the transmission / reception unit 11 and sends a connection completion notification (RRC CONNECTION SETUP COMPLETE) (not shown) to the base station 20 in response to the response 32. Transmit to establish a wireless connection.

  When there is no response from the base station 20, the mobile communication function unit 13 retransmits the wireless connection request. The retransmission of the wireless connection request is performed by measuring the time after the mobile communication function unit 13 transmits (including retransmission) the wireless connection request by the retransmission timer (T300 in 3GPP (3rd Generation Partnership Project)), and the expiration value Retransmission is performed when (300 V in 3GPP) is reached. As the expiration value, for example, a time of about 2 to 3 seconds is set. Information on the number of times of retransmission of the wireless connection request is stored in the storage unit 14, and the mobile communication function unit 13 refers to the information when retransmitting the wireless connection request. The number of times of retransmission of the wireless connection request may be set in advance, or may be set as appropriate based on setting information included in the broadcast information from the base station 20 received by the mobile communication terminal 10. As the number of retransmissions, for example, a frequency of about 5 is set.

  As described above, the mobile communication function unit 13 is means for performing a series of processes related to a wireless connection request to the base station 20. The mobile communication function unit 13 notifies the control unit 16 when a process related to the wireless connection request is started, for example, by transmitting a wireless connection request to the base station 20. In addition, the mobile communication function unit 13 notifies the control unit 16 when the processing related to the wireless connection request ends, for example, when the wireless connection is established or the wireless connection is not established.

  In the cell 21 in the mobile communication network, a connection request restriction (for example, ACC (Access Class Control) restriction in 3GPP (3rd Generation Partnership Project)) prohibiting transmission of a wireless connection request is given to the mobile communication terminal 10. There are some that apply. The connection request restriction is a restriction applied to the mobile communication terminal 10 for each cell 21. Whether the connection request restriction is applied or not is determined in the mobile communication network by, for example, user identification such as UIM (User Identity Module) or SIM (Subscriber Identity Module) connected to each cell 21 and the mobile communication terminal 10 ( For each module class). Whether or not the connection request restriction is applied to the own terminal in the cell 21 can be determined by referring to the information included in the broadcast information related to the cell 21.

  The mobile communication function unit 13 can receive broadcast information transmitted from the base station 20 for location registration or the like. The mobile communication function unit 13 determines the received notification information in order to determine whether or not the connection request restriction that prohibits transmission of the wireless connection request in the cell 21 related to the notification information is applied to the own terminal. 15 to send. That is, the mobile communication function unit 13 receives broadcast information from the base station 20, and based on the received broadcast information, the connection request restriction that prohibits transmission of a wireless connection request in the cell 21 of the base station 20 And determining means for determining whether or not to apply.

  The cell transition is to change the base station 20 with which the mobile communication terminal 10 is a communication partner. Whether or not the cell transition is performed is determined by the mobile communication function unit 13 based on the strength (reception level) of radio waves of the notification information from the base station 20 received by the mobile communication terminal 10. For this determination, a cell transition determination threshold value stored in the storage unit 14 is used. For example, when the radio wave intensity of the migration destination cell 21 (base station 20) is stronger than the radio wave intensity of the migration source cell 21 (base station 20) and exceeds the cell migration judgment threshold, the cell migration is performed. It is determined to do. As shown in FIG. 2, for example, the mobile terminal 10 (the user who carried it) moves from the cell 21a of the base station 20a to the cell 21b of the base station 20b, and the radio waves from the base station 20b are transferred. This is done when the intensity of is higher than that from the base station 20a.

  The storage unit 14 is a storage unit that stores information necessary for control by the mobile communication function unit 13. Specifically, for example, information such as the number of retransmissions of the wireless connection request, the expiration value of the retransmission timer, and the cell transition determination threshold value. These pieces of information are referred to by the mobile communication function unit 13 as necessary.

  Based on the broadcast information received by the mobile communication function unit 13, the determination unit 15 applies a connection request restriction that prohibits transmission of a wireless connection request in the cell 21 of the base station 20 related to the broadcast information to the own terminal. It is a judgment means for judging whether or not. Specifically, the determination unit 15 refers to information included in the broadcast information transmitted from the mobile communication function unit 13 for determining whether or not the connection request restriction is applied, and performs the above determination. Do. In the above determination, information (for example, an ID or the like) that identifies the terminal (a user identification module connected to the terminal) is referred to as necessary.

  When the determination unit 15 determines that the connection request restriction is applied in the cell 21 during the process related to the wireless connection request, the control unit 16 is a control unit that performs control for prohibiting cell transition to the cell 21. is there. It is notified from the mobile communication function unit 13 whether the own terminal is in the process related to the wireless connection request. Specifically, for example, cell prohibition control is performed by controlling the mobile communication function unit 13 so as not to make a determination to perform cell transition.

  Subsequently, processing (cell transition control method) executed by the mobile communication terminal 10 of the present embodiment will be described using the sequence diagram of FIG. In this process, for example, (1) the mobile communication terminal 10 (user carrying the cell) is located in an area near the boundary of the cell 21 (cell transition event occurrence condition), and (2) the cell 21 that can be the cell transition destination Is performed when the connection request restriction for prohibiting transmission of the wireless connection request is applied to the mobile communication terminal 10. In the following description, it is assumed that the mobile communication terminal 10 is located in the cell 21a of the base station 20a. The mobile communication terminal 10 is located at the boundary between the cell 21a of the base station 20a and the cell 21b of the base station 20b. In the cell 21b, a connection request restriction that prohibits transmission of a wireless connection request is mobile communication terminal 10. Is applied to.

  First, in the mobile communication terminal 10, the mobile communication function unit 13 transmits a wireless connection request to the base station 20a via the transmission / reception unit 11 (S01). Transmission of this wireless connection request is triggered by the start of a call or data communication for making a call by a user operation. By transmitting this wireless connection request, a series of processing relating to the wireless connection request is started, and the mobile communication function unit 13 notifies the control unit 16 of this.

  Thereafter, when the mobile communication function unit 13 receives broadcast information from the base station 20b via the transmission / reception unit 11 (S02, determination step), the mobile communication terminal 10 performs the following processing. Note that reception of broadcast information is not always performed only at this timing, but is always performed, but reference to broadcast information as described below is performed at this timing. The broadcast information received by the mobile communication function unit 13 is transmitted to the determination unit 15. Subsequently, in the determination unit 15, it is determined whether or not the connection request restriction that prohibits the transmission of the wireless connection request in the cell 21b is applied to the own terminal based on the notification information (S03, determination step). In the cell 21b, since the connection request restriction is applied to the mobile communication terminal 10, the determination unit 15 makes such a determination. The determination result is notified from the determination unit 15 to the control unit 16.

  Upon receiving the notification, the control unit 16 performs control for prohibiting the cell transition to the cell 21b (S04, control step). This control makes it impossible for the mobile communication terminal 10 to move to the cell 21b. Even if the received broadcast information is of a radio wave intensity that satisfies the cell transition condition, the cell transition to the cell 21b is not performed.

  Since the cell transition to the cell 21b is not performed, the mobile communication terminal 10 performs a process related to the subsequent wireless connection request with the base station 20a (S05). The processing related to the subsequent wireless connection request is, specifically, transmission / reception of a response from the base station 20a to the wireless connection request, transmission / reception of a connection completion notification, and establishment of a wireless connection thereby.

  As described above, during the process related to the wireless connection request, the cell transition to the cell 21b to which the connection request restriction is applied to the mobile communication terminal 10 is not performed. When such a cell transition to the cell 21b is performed, the mobile communication terminal 10 may be in a deadlock state such as being unable to retransmit the wireless connection request. However, according to the present embodiment, the deadlock state is entered. Can be prevented. In addition, when such a cell transition to the cell 21b is performed, the mobile communication terminal 10 cannot retransmit the wireless connection request and thus cannot establish a wireless connection. However, according to the present embodiment, a wireless connection can be established with the base station 20a capable of transmitting a wireless connection request, and the connection rate can be improved.

  In the present embodiment, first, the mobile communication terminal 10 transmits a wireless connection request, so that processing related to the wireless connection request is started. In addition to this, for example, the present invention may be applied to a process of transmitting a wireless connection request corresponding to an incoming signal after receiving the incoming signal. In this case, the processing related to the wireless connection request is started by receiving the incoming signal.

  Further, in the present embodiment, after receiving the broadcast information, it is determined whether or not the connection request restriction is applied in the cell 21 regardless of whether the radio wave intensity related to the broadcast information satisfies the cell transition condition. ing. Other than that, for example, after receiving the broadcast information, it is determined whether the radio wave intensity related to the broadcast information satisfies the cell transition condition, and only when the cell transition condition is satisfied, the connection request regulation is performed in the cell 21. It may be possible to determine whether or not to apply and to prohibit cell migration.

  In the present embodiment, the mobile communication terminal 10 is a mobile phone, but a terminal that can perform mobile communication other than that, such as a PC (Personal Computer) or PDA (Personal) having a mobile communication function. Digital Assistance).

It is a figure which shows the structure of the mobile communication terminal in embodiment of this invention. It is a figure which shows the outline | summary of the function of a mobile communication terminal. It is a sequence diagram which shows the process (cell transfer control method) performed with the mobile communication terminal in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Mobile communication terminal, 11 ... Transmission / reception part, 12 ... Mobile telephone function part, 13 ... Mobile communication function part, 14 ... Memory | storage part, 15 ... Judgment part, 16 ... Control part, 20 ... Base station, 21 ... Cell.

Claims (2)

A mobile communication terminal that performs processing related to a wireless connection request to a base station including retransmission of a wireless connection request to a base station,
The broadcast information is received from a base station different from the base station that is the target of the wireless connection request, and it is determined whether or not the radio wave intensity related to the broadcast information from the other base station satisfies the cell transition condition. If it is determined that the radio field strength satisfies the conditions for cell transition, whether or not connection request regulation for prohibiting transmission of a wireless connection request in the cell of the base station is applied to the terminal based on the received broadcast information A judging means for judging whether or not
During the process related to the wireless connection request started by transmission of the wireless connection request, the determination means controls the connection request restriction in a cell different from the cell of the base station that is the target of the wireless connection request. A control means for performing a control for prohibiting the cell transition to another cell,
A mobile communication terminal comprising: A cell mobility control method in a mobile communication terminal that performs processing related to a wireless connection request to a base station including retransmission of a wireless connection request to a base station,
The broadcast information is received from a base station different from the base station that is the target of the wireless connection request, and it is determined whether or not the radio wave intensity related to the broadcast information from the other base station satisfies the cell transition condition. If it is determined that the radio field strength satisfies the conditions for cell transition, whether or not connection request regulation for prohibiting transmission of a wireless connection request in the cell of the base station is applied to the terminal based on the received broadcast information A determination step for determining whether or not
During the process related to the wireless connection request started by transmission of the wireless connection request, in the determination step, the connection request regulation is automatically performed in the cell different from the cell of the base station that is the target of the wireless connection request. A control step for performing control to prohibit cell transition to another cell when determined to be applied to the terminal;
A cell movement control method including:

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