JP2014150305A - Mobile station device, radio communication system, radio communication method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile station device that, even if an emergency transmission base station device is a communication object person, searches an emergency transmission base station device that can be communicated with the mobile station device and maintains a state in which the mobile station device can communicate with the emergency transmission base station device.SOLUTION: A mobile station device 1 that establishes communication with an emergency transmission base station device that does not routinely transmit an idle line signal to a mobile station device comprises: a transmission unit 10 that transmits a prescribed synchronization signal (SB0 signal) with the use of a prescribed channel; a determination unit 11 that determines whether or not the mobile station device received a return signal in response to the SB0 signal from the emergency transmission base station device by the channel that has transmitted the SB0 signal; and a channel setting unit 12 that sets the channel that has received the return signal as a communication channel if the return signal was received.

Description

  The present invention relates to a mobile station apparatus, a radio communication system, a radio communication method, and a program for establishing radio communication with an emergency transmission base station apparatus.

  In the field of fire fighting / emergency radio, a technique for establishing radio communication between a mobile station apparatus and a base station apparatus by digital radio communication of SCPC (Single Channel Per Carrier) method is used.

  Here, the base station apparatus performs a voice call with the mobile station apparatus, a regular transmission base station apparatus that continuously transmits a radio signal (empty line signal) even during a period in which radio communication with the mobile station apparatus or the like is not performed. There is an emergency transmission base station apparatus that transmits a radio signal only during a necessary period and stops transmission during other periods. The emergency transmission base station apparatus is configured not to transmit an empty signal during a period other than necessary wireless communication in order to avoid regulations such as the Radio Law, particularly interference with adjacent base station apparatuses.

FIG. 10 is a diagram for explaining an operation at the time of handover in a related mobile station apparatus.
Here, the handover (switching process of the communication target base station accompanying the movement of the mobile station) by the mobile station apparatus 71 related to the present invention will be described with reference to FIG. A normal mobile station apparatus 71 related to the present invention performs wireless communication with a regular transmission base station apparatus 72A or 72B. In FIG. 10, the area where the mobile station device 71 can receive the radio signal transmitted by the regular transmission base station device 72A is defined as the communication area A, and the mobile station device 71 receives the radio signal transmitted by the regular transmission base station device 72B. A possible area is a communication area B. Further, it is assumed that the channel used by the constant transmission base station apparatus 72A is “CH1” and the channel used by the constant transmission base station apparatus 72B is “CH2”.

  Initially, it is assumed that the mobile station device 71 exists outside the communication area B and at a position a belonging to the communication area A. At this time, the regular transmission base station device 72A constantly transmits an idle signal using the channel “CH1”. The mobile station device 71 also sets the communication channel to the channel “CH1” and receives the empty line signal from the regular transmission base station device 72A. The airline signal transmitted by the regular transmission base station device 72A includes predetermined broadcast information. This broadcast information includes channel information used by the base station apparatus adjacent to the regular transmission base station apparatus 72A and channel information of the base station apparatus 72A. Based on the broadcast information, the mobile station device 71 can obtain information necessary for establishing communication with the base station device adjacent to the current area.

  Next, it is assumed that the mobile station device 71 has moved from the position a to the position b belonging to the outside of the communication area A and within the communication area B. Then, the mobile station device 71 is that the reception intensity of the skyline signal using the channel “CH1” here (that is, the skyline signal from the regular transmission base station device 72A) has dropped below a predetermined threshold. Is detected (step S100).

  Next, the mobile station device 71 confirms the reception strength of the radio signal by a channel other than the channel “CH1” (step S101). Here, the mobile station apparatus 71 sets the communication channel with reference to the broadcast information received from the constant transmission base station apparatus 72A when confirming the reception strength of the radio signal by another channel. On the other hand, the regular transmission base station apparatus 72B adjacent to the regular transmission base station apparatus 72A transmits an empty line signal using the channel “CH2” within the communication area B range. The mobile station device 71 specifies a channel “CH2” having a reception strength equal to or higher than a predetermined threshold in the process of checking the reception strength while matching the communication channels in order based on the broadcast information (step S102). Then, the regular transmission base station apparatus 72B sets the communication channel to “CH2” (step S103).

  As described above, even if the mobile station device 71 moves outside the range of the communication area A that can communicate with the regular transmission base station device 72A as described above, the mobile station device 71 immediately detects another communication channel and detects other regular transmission base stations. Wireless communication with device 72B can be established.

  As a technique related to the above-described contents, a base station apparatus in which an emergency transmission base station temporarily functions as a regular transmission base station (when in a “temporary regular transmission mode”) when a predetermined condition is satisfied is disclosed. (Patent Document 1).

JP 2011-244150 A

FIG. 11 is a diagram for explaining a problem in operation during handover in a related mobile station apparatus.
As described above, there are two types of base station apparatuses, a regular transmission base station apparatus and an emergency transmission base station apparatus. Here, the handover technique described in FIG. 10 is based on the premise that all base station apparatuses are regular transmission base station apparatuses. FIG. 11 shows a case where the base station apparatus in FIG. 10 is not the regular transmission base station apparatuses 72A and 72B but both are the emergency transmission base station apparatuses 82A and 82B.

  In this case, since the emergency transmission base station devices 82A and 82B do not regularly transmit the sky line signal, the mobile station device 71 may receive the sky line signal from the base station device and the broadcast information included therein. Can not. Then, when the mobile station apparatus 71 moves from the position a shown in FIG. 9 to the position b, the mobile station apparatus 71 itself can receive at the timing when the own apparatus is out of the communication area A and at the position b. The channel cannot be specified.

  Here, the base station apparatus disclosed in Patent Document 1 is characterized in that it switches from the “emergency transmission mode” to the “temporary constant transmission mode” when a predetermined SB0 signal is received from the mobile station apparatus. However, the base station device originally needs to comply with related regulations such as the Radio Law regarding the emission of radio waves to the public. However, the emergency transmission base station device may operate as a regular transmission base station due to its regulations. It is also possible to be restricted.

  If the emergency transmission base station device cannot transmit a radio signal steadily like a regular transmission base station due to regulations such as the Radio Law, the base station device described in Patent Document 1 cannot cope with it.

  Accordingly, an object of the present invention is to provide a mobile station apparatus, a wireless communication system, a wireless communication method, and a program that can solve the above-described problems.

  The present invention has been made in order to solve the above-described problems, and includes a transmitter that transmits a predetermined synchronization signal using a predetermined channel and an emergency transmission base station device that does not normally transmit a radio signal. A determination unit that determines whether or not a loopback signal for a signal is received by the predetermined channel; and a channel setting unit that sets the channel that has received the loopback signal as a communication channel when the loopback signal is received And the determination unit determines that the return signal has been received from the emergency transmission base station device on the condition that the reception strength of the return signal is equal to or higher than a predetermined threshold. Device.

  In addition, the present invention provides a transmitter in which a mobile station apparatus transmits a predetermined synchronization signal using a predetermined channel, and a loopback signal for the synchronization signal from the emergency transmission base station apparatus using the predetermined channel. And a channel setting unit that sets a channel that has received the loopback signal as a communication channel when the loopback signal is received. When an emergency transmission base station apparatus that does not regularly transmit radio signals to a station apparatus receives the synchronization signal, a transmission unit that transmits a return signal using a channel used by the received synchronization signal A wireless communication system is provided.

  In the present invention, the mobile station apparatus transmits a predetermined synchronization signal using a predetermined channel, and the emergency transmission base station apparatus that does not regularly transmit a radio signal to the mobile station apparatus When a signal is received, a loopback signal is transmitted using a channel used by the received synchronization signal, and the mobile station device uses the predetermined channel to transmit the synchronization signal from the emergency transmission base station device. In the wireless communication method, it is determined whether or not a loopback signal has been received, and when the loopback signal is received, a channel that has received the loopback signal is set as a communication channel. .

  According to another aspect of the present invention, a computer of a mobile station apparatus that establishes communication with an emergency transmission base station apparatus that does not regularly transmit an empty line signal to the mobile station apparatus is transmitted to a predetermined synchronization signal using a predetermined channel. A transmission means for transmitting, a determination means for determining whether or not a loopback signal is received for the synchronization signal from the emergency transmission base station apparatus using the predetermined channel, and when the loopback signal is received The program is characterized by functioning as channel setting means for setting the channel that has received the return signal as a communication channel.

  According to the present invention, even when the emergency transmission base station device is a communication target, the mobile station detects the emergency transmission base station device that can communicate with itself and maintains a state in which the emergency transmission base station device can communicate with the emergency transmission base station device. The effect that a station apparatus, a wireless communication system, a wireless communication method, and a program can be provided is obtained.

It is a figure which shows the minimum structure of the mobile station apparatus by each embodiment of this invention. It is a figure which shows the function structure of the radio | wireless communications system which consists of the mobile station apparatus and base station apparatus by 1st embodiment of this invention. It is a figure which shows the processing flow of the mobile station apparatus by 1st embodiment of this invention. It is a figure which shows the channel search process of the mobile station apparatus by 1st embodiment of this invention. It is a figure explaining the operation | movement at the time of the handover in the radio | wireless communications system by 1st embodiment of this invention. It is a figure which shows the processing flow of the mobile station apparatus by 2nd embodiment of this invention. It is a figure which shows the channel search process of the mobile station apparatus by 2nd embodiment of this invention. It is a figure which shows the function structure of the radio | wireless communications system which consists of a mobile station apparatus and base station apparatus by 3rd embodiment of this invention. It is base station information which the memory | storage part of the mobile station apparatus by 3rd embodiment of this invention memorize | stores. It is a figure explaining the operation | movement at the time of the handover in a related mobile station apparatus. It is a figure explaining the problem of the operation | movement at the time of a handover in the related mobile station apparatus.

Hereinafter, mobile station apparatuses according to embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a minimum configuration of a mobile station apparatus according to each embodiment of the present invention. In this figure, reference numeral 1 denotes a mobile station apparatus.

  The mobile station apparatus 1 is a mobile station apparatus that establishes communication with an emergency transmission base station apparatus that does not normally transmit a radio signal (sky line signal). The mobile station apparatus 1 uses a predetermined channel to transmit a predetermined synchronization signal (SB0 signal), and a channel that transmits the SB0 signal from the emergency transmission base station apparatus as a return signal for the SB0 signal. And a determination unit 11 that determines whether or not the data has been received. And the mobile station apparatus 1 is provided with the channel setting part 12 which sets the channel which received the said return signal as a communication channel, when a return signal is received.

<First embodiment>
Hereinafter, a mobile station apparatus according to a first embodiment of the present invention will be described with reference to the drawings.
FIG. 2 is a diagram illustrating a functional configuration of a radio communication system including a mobile station apparatus and a base station apparatus according to the first embodiment of the present invention.

  Here, the radio communication system 100 shown in FIG. 2 includes the mobile station apparatus 1 and the emergency transmission base station apparatus 2. It is assumed that emergency transmission base station apparatus 2 is defined as a base station apparatus that performs radio communication using channel “CHx”. The channel “CHx” uses the frequency FHx for uplink communication (wireless communication from the mobile station apparatus 1 to the base station apparatus 2) and for downlink communication (wireless communication from the base station apparatus 2 to the mobile station apparatus 1). Is a channel using the frequency FLx.

  The “channel” (CHx) means a combination of the frequency for uplink communication (FLx) and the frequency for downlink communication (FHx). In principle, one channel is assigned to each base station apparatus. It is what However, if the distance between the base station apparatuses is far away and there is no risk of interference, the same channel may be assigned to different base station apparatuses. Further, the same channel may be allocated in adjacent base stations.

  The transmitting unit 10 of the mobile station device 1 is a functional unit that transmits various signals such as voice information in a voice call in addition to a predetermined synchronization signal, that is, an SB0 (Synchronous Burst 0) signal, by wireless communication. Here, the SB0 signal is a signal having a predetermined preamble pattern for obtaining synchronization so that one device establishes wireless communication with the other device. The SB0 signal can include predetermined information in addition to the preamble. The transmission unit 10 transmits various radio signals at the frequency (FLx) designated by the communication channel (CHx) set by the channel setting unit 12 (described later).

  The receiving unit 13 is a functional unit that receives a radio signal from an external device. The receiving unit 13 receives various radio signals in accordance with the frequency (FHx) designated by the communication channel (CHx) set by the channel setting unit 12 (described later).

  The determination unit 11 detects the reception intensity of the signal received by the reception unit 13. In particular, it is determined whether or not a return signal for the SB0 signal has been received from the emergency transmission base station apparatus 2. Here, the determination unit 11 may be configured to determine that the return signal is received from the emergency transmission base station device 2 on condition that the reception strength P of the return signal is equal to or higher than a predetermined threshold value Pth.

  The channel setting unit 12 is a functional unit that sets a communication channel to be actually applied to the mobile station apparatus 1 with reference to the determination result of the determination unit 11. When the determination unit 11 determines that the return signal for the SB0 signal has been received, the channel setting unit 12 belongs to the communication area of the emergency transmission base station device 2 to which the own device has transmitted at least the return signal. Then, the channel that has received the return signal is set as a communication channel. By doing in this way, the mobile station apparatus 1 can maintain the state which can establish favorable radio | wireless communication also with respect to the emergency transmission base station apparatus 2. FIG.

Further, the determination unit 11 and the channel setting unit 12 are assumed to have the functions of the control unit 14 of the mobile station apparatus 1. The control unit 14 is, for example, a general-purpose CPU (Central Process Unit) and the like, and is a functional unit that implements various functions of the mobile station device 1. The control unit 14 reads out a predetermined program stored in a storage unit (not shown) separately included in the mobile station device 1 to realize various functions. Further, it is assumed that the SB0 signal and other various signals transmitted from the transmission unit 10 are transmitted in accordance with instructions from the control unit 14.
However, in the present embodiment, the determination unit 11 and the channel setting unit 12 do not have to be realized by the control unit 14. For example, the determination unit 11 and the channel setting unit 12 may be implemented by hardware that exhibits each function.

  The emergency transmission base station apparatus 2 includes a reception unit 21, a transmission unit 22, and a control unit 23. The emergency transmission base station apparatus 2 is a base station apparatus that does not regularly transmit a skyline signal for the purpose of regulation based on the Radio Law or the like and to avoid interference with an adjacent base station apparatus.

  The receiving unit 21 of the emergency transmission base station device 2 is a functional unit that receives various signals such as the SB0 signal from the mobile station device 1. The transmission unit 22 is a functional unit that transmits a radio signal on which predetermined information is superimposed to the mobile station device 1 or the like. The signal received by the receiving unit 21 is read by the control unit 23. The control unit 23 performs appropriate processing based on the received signal. In particular, when the control unit 23 receives an SB0 signal using the channel “CHx” from the mobile station device 1, the control unit 23 uses the channel “CHx” assigned to the emergency transmission base station device 2 via the transmission unit 22. Send a loopback signal.

  In general, before the emergency transmission base station apparatus stops transmission, it is necessary to transmit an empty signal a predetermined number of times. For this reason, it is necessary for the emergency transmission base station apparatus to stop transmission after receiving the SB0 signal from the mobile station apparatus and transmitting the return signal and then transmitting the empty line signal a predetermined number of times.

  If it is necessary to transmit the skyline signal a predetermined number of times before the emergency transmission base station apparatus stops transmission, the emergency transmission base station apparatus 2 causes extra radio waves (skyline signals) in the “channel search” process described below. ) Will continue to be sent. Therefore, the transmission unit 22 of the mobile station apparatus 1 determines that the emergency transmission base station apparatus 2 stops all transmissions at the timing next to the transmission of the return signal by the emergency transmission base station apparatus 2 with respect to the SB0 signal. The “channel switching identifier” may be multiplexed with the SB0 signal and transmitted. That is, the emergency transmission base station device 2 transmits a loopback signal a predetermined number of times after transmitting a return signal according to the content of the “channel switching identifier” multiplexed on the SB0 signal received by itself, Transmission may be stopped immediately.

  For example, the transmission unit 22 of the mobile station apparatus 1 according to the present embodiment multiplexes the channel switching identifier “0” for the SB0 signal that is normally transmitted at the time of voice communication press or non-voice communication. The channel switching identifier “1” is multiplexed on the SB0 signal transmitted in the “channel search” process. For example, when the channel switching identifier is “1” in the SB0 signal received by the emergency transmission base station apparatus 2, the emergency transmission base station apparatus 2 transmits the loopback signal and then does not transmit the empty line signal. Stop sending immediately.

FIG. 3 is a diagram showing a processing flow of the control unit of the mobile station apparatus according to the first embodiment of the present invention.
The transmission unit 10 according to the present embodiment sequentially transmits the SB0 signal for each of the plurality of channels, and the channel setting unit 12 sets any one of the channels that have received the return signal for each of the SB0 signals as a communication channel. It is characterized by doing. Hereinafter, this function will be specifically described with reference to FIG.

  First, the control unit 14 of the mobile station apparatus 1 determines whether or not a radio signal from the base station apparatus can be received on the currently set communication channel. Specifically, the determination unit 11 determines whether or not the reception strength P of the radio signal is less than a predetermined threshold Pth (step S10). Here, for example, when the mobile station device 1 is in the communication area of the regular transmission base station device and is in a state where communication with the regular transmission base station device is possible, it is not necessary to change the communication channel at this point. Therefore, the control part 14 complete | finishes a processing flow, when the receiving intensity P is more than the threshold value Pth in the currently set communication channel.

  Next, in step S10, when the reception strength P is less than the threshold value Pth in the currently set communication channel, the control unit 14 performs a channel search to detect a new communication destination. Here, the control unit 14 first determines whether or not a predetermined period has elapsed since the previous channel search was performed (step S11). This is intended to repeat the channel search every predetermined period in an environment in which the mobile station apparatus 1 cannot receive signals steadily in the communication channel being set. In step S11, a timer function provided in advance in the control unit 14 may be used.

  Next, when a predetermined period has elapsed in step S11, the control unit 14 starts a channel search (step S12). In the channel search, the control unit 14 transmits the SB0 signal while changing the communication channel in order, and determines whether or not there is a return signal from the emergency transmission base station device. Hereinafter, a specific processing flow of the channel search will be described.

  The control unit 14 determines whether or not transmission of the SB0 signal has been completed for all channels in the channel search (step S13). This means that if there is no return signal for the SB0 signal for all channels, the control unit 14 terminates the channel search assuming that the mobile station device 1 is not in the communication area of any emergency transmission base station device 2. Intended.

  In step S13, when the SB0 signal is not transmitted for all channels, the channel setting unit 12 of the control unit 14 sets a predetermined channel among the settable channels (step S14). In step S <b> 14, the channel setting unit 12 sets a channel while sequentially changing from the previously set channel. For example, it is assumed that there are n channels that can be set as communication channels from channels “CH1” to “CH_n”. Then, the channel setting unit 12 sets the communication channel to the channel “CH1” in the first step S14, and changes it to “CH2”, “CH3”,... “CH_n” in each subsequent step S14. Go.

  Next, the control part 14 transmits SB0 signal via the transmission part 10 using the communication channel set by step S14 (step S15). And the determination part 11 of the control part 14 performs reception intensity measurement about the channel used for transmission of the said SB0 signal for a predetermined period after transmission of the SB0 signal (step S16). The control unit 14 determines whether or not a predetermined period has elapsed since the transmission of the SB0 signal (step S17), and continues the reception intensity measurement in step S16 by the determination unit 11 until the predetermined period elapses. .

  When the predetermined period has elapsed in step S17, the determination unit 11 determines whether or not the reception intensity P is equal to or greater than a predetermined threshold Pth (step S18). Here, when the determination unit 11 determines that the reception intensity P is less than the threshold value Pth, it is determined that there is no return signal for the SB0 signal transmitted in step S15, and the process returns to step S13 to set to the next channel.

  On the other hand, when the determination unit 11 determines that the reception strength P is equal to or greater than the predetermined threshold Pth in step S18, the control unit 14 communicates with the emergency transmission base station apparatus 2 through the communication channel set in step S14. Is determined to be possible, the subsequent channel search is stopped, and the processing flow ends.

FIG. 4 is a diagram showing channel search processing of the mobile station apparatus according to the first embodiment of the present invention.
According to the processing flow of FIG. 3, the transmitting unit 10 of the mobile station apparatus 1 first receives a return signal from the emergency transmission base station apparatus 2 in the process of sequentially transmitting a plurality of SB0 signals. If it is determined, the transmission of the SB0 signal is stopped at that time. And the channel setting part 12 sets the channel which received the return signal first as a communication channel.

Specifically, the mobile station apparatus 1 exchanges radio signals as shown in FIG. 4 with the emergency transmission base station apparatus 2 when performing a channel search. Note that the wireless signal exchange shown in FIG. 4 is based on the premise that the mobile station apparatus 1 is not in a situation where it can receive an empty line signal or the like from another regular transmission base station apparatus. The mobile station device 1 is assumed to be located within the communication area of the emergency transmission base station device 2, and is not assumed to be within the communication area of other base station devices. Further, it is assumed that the emergency transmission base station apparatus 2 is a base station apparatus that performs communication using, for example, the channel “CH_k”.
The step numbers shown in FIG. 4 correspond to the step numbers in the flowchart shown in FIG.

  As shown in FIG. 4, when starting a channel search (step S12), the mobile station apparatus 1 first sets a channel “CH1” as a communication channel (step S14). Then, the mobile station apparatus 1 transmits the SB0 signal using the channel “CH1”. Since the emergency transmission base station apparatus 2 cannot receive the SB0 signal by the channel “CH1”, the emergency transmission base station apparatus 2 does not transmit the return signal for the SB0 signal (step S20 ′).

  When the mobile station apparatus 1 detects that there is no return signal for a predetermined period (steps S17 to S18 in FIG. 3), it sets the communication channel to the next channel “CH2” and uses the channel “CH2” to set SB0. Send a signal. However, since the emergency transmission base station apparatus 2 cannot receive the SB0 signal by the channel “CH2” as in the previous time, the emergency transmission base station apparatus 2 does not transmit the return signal for the SB0 signal.

  The mobile station device 1 repeats the process of transmitting the SB0 signal while changing the communication channel settings one after another. Then, it is assumed that the mobile station apparatus 1 sets the communication channel to channel “CH_k”. The mobile station apparatus 1 transmits the SB0 signal using the channel “CH_k”. The emergency transmission base station apparatus 2 receives the SB0 signal by the channel “CH_k” and immediately transmits a return signal for the SB0 signal (step S20).

  As described above, when the determination unit 11 first determines that the return signal is received from the emergency transmission base station device, the mobile station device 1 stops the channel setting change and the transmission of the SB0 signal at that time, and performs the return. The channel that first receives the signal is set as the communication channel.

  FIG. 5 is a diagram for explaining the operation at the time of handover in the wireless communication system according to the first embodiment of the present invention. In FIG. 5, the area where the mobile station device 71 can receive the radio signal transmitted by the emergency transmission base station device 2A is defined as the communication area A, and the mobile station device 71 receives the radio signal transmitted by the emergency transmission base station device 2B. A possible area is a communication area B. Further, the channel used by the emergency transmission base station apparatus 2A is the channel “CH1”, and the channel used by the emergency transmission base station apparatus 2B is the channel “CH2”.

  FIG. 5 shows a state in which the mobile station device 1 according to the present embodiment realizes handover by the above-described processing. Here, first, it is assumed that the mobile station apparatus 1 is at a position a in the communication area A of the emergency transmission base station apparatus 2A. Since the mobile station device 1 has not received the skyline signal from the regular transmission base station device (step S10 in FIG. 3), the above-described channel search is started at a predetermined timing (step S12 in FIG. 3).

  When the mobile station apparatus 1 receives a return signal from the emergency transmission base station apparatus 2A for the SB0 signal transmitted using the channel “CH1” as a result of the channel search, the channel “CH1” is set as the communication channel thereafter. The With this setting, the mobile station apparatus 1 can perform wireless communication with the emergency transmission base station apparatus 2A via the channel “CH1” at least while in the communication area A.

  Next, it is assumed that the mobile station apparatus 1 moves and reaches a position b located outside the communication area A and within the communication area B. However, since the emergency transmission base station devices 2A and 2B do not transmit a radio signal except when necessary wireless communication (does not transmit an empty line signal), the mobile station device 1 cannot detect that the communication area A has been removed. . Further, the mobile station device 1 itself cannot enter the communication area B and cannot detect that wireless communication with the emergency transmission base station device 2B is possible via the channel “CH2”.

  However, the mobile station apparatus 1 automatically starts the channel search again when a predetermined period has elapsed since the previous channel search (step S11 in FIG. 3). Therefore, regardless of whether the mobile station apparatus 1 enters or does not enter the communication area B, the mobile station apparatus 1 performs the channel search again after a predetermined period from the previous channel search. Then, as a result of performing the channel search again, the mobile station apparatus 1 receives the return signal from the emergency transmission base station apparatus 2B in response to the SB0 signal transmitted using the channel “CH2”, and thereafter the channel “CH2” as the communication channel. Is set.

  As described above, since the mobile station device 1 performs a channel search every predetermined period, even if the communication area of the base station device changes before the device itself intends, a channel that can be communicated for each channel search. Find and reset.

  As described above, according to the present invention, even when the emergency transmission base station device is a communication target, the emergency transmission base station device that can communicate with the emergency transmission base station device is detected by itself, and the state in which the emergency transmission base station device can communicate with the emergency transmission base station device is maintained. A mobile station device can be provided.

  The control unit 14 of the mobile station apparatus 1 according to the present embodiment has been described as performing a channel search every time a predetermined period elapses, but in the present embodiment, the channel search is performed at other timings. It doesn't matter. For example, the channel search may be executed at a timing when a predetermined instruction from the operator of the mobile station apparatus 1 is received. Further, the mobile station device 1 may execute the channel search at the timing when the power of the own device is turned on or when the mobile station device 1 moves a predetermined distance.

<Second Embodiment>
Hereinafter, a mobile station apparatus according to a second embodiment of the present invention will be described with reference to the drawings. Note that the functional configuration of the mobile station apparatus 1 according to the second embodiment is the same as that of the first embodiment (FIG. 2), and thus the description thereof is omitted.
The determination unit 11 according to the present embodiment stores the reception strength of each of the return signals for the plurality of SB0 signals, and the channel setting unit 12 sets the channel having the highest reception strength as a communication channel. The function will be specifically described below with reference to the drawings.

FIG. 6 is a diagram showing a processing flow of the mobile station apparatus according to the second embodiment of the present invention.
Among the processing steps shown in FIG. 6, the same processing steps as those in the first embodiment (FIG. 3) are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  Here, the control unit 14 of the mobile station device 1 according to the second embodiment performs channel setting in the same manner as in the first embodiment (Step S14) when starting channel search (Step S12), and further The SB0 signal is transmitted using the channel (step S15). Then, the determination unit 11 measures the reception strength to determine whether or not there is a return signal from the emergency transmission base station apparatus for the channel (steps S16 to S17).

Next, the determination unit 11 temporarily stores the measured received signal strength of the return signal in association with the currently set channel (step S30). Specifically, the determination unit 11 sequentially stores the received intensity together with the corresponding channel number (channel identifier).
The control unit 14 of the mobile station apparatus 1 according to the present embodiment performs the SB0 transmission process (steps S14 to S15) while changing the communication channel regardless of the presence or absence of a return signal from the emergency transmission base station apparatus 2. Repeat for (“CH1” to “CH_n”). When the mobile station apparatus 1 finishes transmitting the SB0 signal for all channels, the determination unit 11 stores the reception strength of each of the return signals for the plurality of SB0 signals for all channels.

  When the mobile station apparatus 1 transmits the SB0 signal for all channels (step S13 → YES), the channel setting unit 12 compares the reception strengths temporarily stored by the determination unit 11 and the channel with the highest reception strength. Is set as a communication channel (step S31).

FIG. 7 is a diagram showing channel search processing of the mobile station apparatus according to the second embodiment of the present invention.
The mobile station apparatus 1 according to the present embodiment exchanges radio signals as shown in FIG. 7 with the emergency transmission base station apparatus 2 when performing a channel search. Note that the radio signal exchange shown in FIG. 7 is based on the premise that the mobile station device 1 is not in a situation where it can receive an empty line signal or the like from another regular transmission base station device as in FIG. 4 in the first embodiment. It is said. Further, it is assumed that the mobile station device 1 is located within the communication area of the emergency transmission base station device 2A, and is also within the communication area of another emergency transmission base station device 2B. The emergency transmission base station device 2A is a base station device that performs communication using, for example, the channel “CH_k”, while the emergency transmission base station device 2B is a base station device that performs communication using the channel “CH_n”. Suppose there is.
Note that the step numbers shown in FIG. 7 correspond to the step numbers in the flowchart shown in FIG.

  As shown in FIG. 7, when starting the channel search (step S12), the mobile station apparatus 1 first sets the channel “CH1” as the communication channel (step S14). Then, the mobile station apparatus 1 transmits the SB0 signal using the channel “CH1”. The emergency transmission base station apparatuses 2A and 2B cannot receive the SB0 signal by the channel “CH1”, and therefore do not transmit a return signal for the SB0 signal (step S20 ′).

  The mobile station device 1 stores the reception strength P of the return signals from the emergency transmission base station devices 2A and 2B (step S30 in FIG. 6) (even if there is no return signal, the reception strength data is “0”). Remember). Next, the mobile station apparatus 1 sets the communication channel to the next channel “CH2”, and transmits the SB0 signal using the channel “CH2”. Then, the mobile station apparatus 1 acquires and stores the reception strength of the return signal with respect to the SB0 signal transmitted using “CH2”.

  The mobile station device 1 repeats the process of transmitting the SB0 signal while changing the communication channel settings one after another. Then, it is assumed that the mobile station apparatus 1 sets the communication channel to channel “CH_k”. The mobile station apparatus 1 transmits the SB0 signal using the channel “CH_k”. The emergency transmission base station device 2A receives the SB0 signal by the channel “CH_k”, and immediately transmits a return signal for the SB0 signal by the same channel (CH_k) (step S20A). On the other hand, since the base station apparatus 2B cannot receive the “CH_k” SB0 signal, it still does not transmit the return signal. Then, the mobile station apparatus 1 acquires and stores the reception strength of the return signal (the return signal transmitted by the emergency transmission base station apparatus 2A) with respect to the SB0 signal transmitted using “CH_k”.

  The mobile station apparatus 1 according to the present embodiment continuously repeats the above processing (steps S14 to S30 in FIG. 6) until SB0 signals are transmitted for all channels. When the mobile station apparatus 1 transmits the SB0 signal using the channel “CH_n”, the emergency transmission base station apparatus 2B receives the SB0 signal and immediately transmits a return signal for the SB0 signal (step S20B). . On the other hand, at this time, the base station apparatus 2A cannot receive the “CH_n” SB0 signal, and therefore does not transmit the return signal. Then, the mobile station apparatus 1 acquires and stores the reception strength of the return signal (the return signal transmitted by the emergency transmission base station apparatus 2B) with respect to the SB0 signal transmitted using “CH_n”.

  When the mobile station apparatus 1 performs transmission of the SB0 signal and measurement of the reception strength for all channels, the channel setting unit 12 finally sets the channel with the highest reception strength among all the channels as the communication channel (step S31). .

  As described above, the mobile station apparatus 1 according to the second embodiment detects the presence / absence of the return signal of the emergency transmission base station apparatus 2 for all channels. When there are return signals from a plurality of emergency transmission base station devices 2, the mobile station device 1 exchanges a channel from which the best radio communication can be expected, that is, a channel with the highest reception strength. Set as trusted channel.

  As described above, according to the present invention, it is possible to provide a mobile station apparatus that enables better wireless communication to an emergency transmission base station apparatus.

  In the second embodiment, as in the first embodiment, the channel search may be executed at a timing other than the elapse of a predetermined period.

<Third embodiment>
Hereinafter, the mobile station apparatus by 3rd embodiment of this invention is demonstrated with reference to drawings.
FIG. 8 is a diagram illustrating a functional configuration of a wireless communication system including a mobile station apparatus and a base station apparatus according to the third embodiment of the present invention. Here, the radio communication system 100 shown in FIG. 8 includes the mobile station apparatus 1 and the emergency transmission base station apparatus 2. In FIG. 8, the same functional configuration as that of the first embodiment and the second embodiment is denoted by the same reference numeral, and description thereof is omitted.

  The mobile station device 1 according to the third embodiment includes a location information acquisition unit 15 that acquires location information of the device itself, location information of the emergency transmission base station device 2, and a channel used by the emergency transmission base station device 2. , And a storage unit 16 that stores in advance base station information stored in association with each other.

  The position information acquisition unit 15 is a functional unit realized by, for example, GPS (Global Positioning System). The mobile station apparatus 1 can grasp where the own apparatus exists via the position information acquisition unit 15. The position information acquisition unit 15 detects coordinate information (X, Y) on a predetermined map based on a signal received by the GPS with respect to the position of the device itself.

FIG. 9 shows base station information stored in the storage unit of the mobile station apparatus according to the third embodiment of the present invention.
The mobile station apparatus 1 stores “base station information” in which the location information of the emergency transmission base station apparatus 2 and the channel information used by each emergency transmission base station apparatus 2 are associated with each other in the storage unit 16 in advance. For example, as shown in FIG. 9, the base station information is “location information” of the emergency transmission base station apparatus 2 for “emergency transmission base station apparatus numbers” that individually identify a plurality of emergency transmission base station apparatuses 2. And an “in-use channel”.

And the transmission part 10 of the mobile station apparatus 1 by 3rd embodiment transmits the SB0 signal about the channel which the emergency transmission base station apparatus 2 which exists in the predetermined range from the position of an own apparatus is characterized. .
Here, the channel search of the mobile station apparatus 1 according to the third embodiment will be described. The channel search of the mobile station apparatus 1 according to the third embodiment is equivalent to the second embodiment (FIGS. 6 and 7). However, the channel setting at the time of channel search (step S14 in FIG. 6) does not cover all channels (“CH1” to “CH_n”), and exists within a predetermined range from the position of the own device. Only the channel used by the transmission base station apparatus 2 is targeted.

  Specifically, in the process of step S <b> 14, the control unit 14 first acquires the position information (X, Y) of the own device from the position information acquisition unit 15. Then, the control unit 14 compares the position information of each emergency transmission base station device 2 stored in the base station information with the position information of the own device, and determines the distance between each emergency transmission base station device 2 and the own device. Calculate and extract the emergency transmission base station apparatus 2 located within a predetermined range from the own apparatus. Further, the control unit 14 refers to the channel used by the extracted emergency transmission base station apparatus 2 based on the base station information. And the control part 14 transmits SB0 signal about the channel which the emergency transmission base station apparatus 2 referred refers to via the transmission part 10. FIG.

That is, the mobile station apparatus 1 according to the present embodiment does not perform channel search on the channel used by the emergency transmission base station apparatus 2 existing at a position away from the own apparatus, but exists near the own apparatus. It has a target channel limiting function for executing a channel search only for the channel of the transmission base station apparatus 2. Note that the emergency transmission base station apparatus 2 to be subjected to channel search may be all emergency transmission base station apparatuses 2 whose distance from the own apparatus is equal to or less than a predetermined value, or a predetermined number of emergency transmission base stations that are close to the own apparatus. The transmission base station device 2 may be used.
In this way, the mobile station device 1 only needs to transmit the SB0 signal only for the emergency transmission base station device 2 that is expected to be communicable based on the GPS function and the base station information stored in advance. , It is not necessary to transmit the SB0 signal for all the channels and acquire the reception intensity. The order of the channels used for transmitting the SB0 signal at the time of channel search may be the order of the emergency transmission base station apparatus 2 close to the mobile station apparatus 1 or a single emergency transmission base station apparatus 2 may have a plurality of channels. If assigned, the channels within the same emergency transmission base station apparatus 2 may be selected from the lowest number or may be selected at random.

  As described above, according to the present invention, it is possible to provide a mobile station apparatus capable of more promptly processing a channel search performed to enable radio communication with an emergency transmission base station apparatus.

  In the third embodiment described above, the processing flow of the control unit 14 of the mobile station apparatus 1 is based on the second embodiment. However, in this embodiment, the processing flow of the control unit 14 is It may be based on the first embodiment.

  Also in the third embodiment, similarly to the first embodiment and the second embodiment, the channel search may be executed at a timing other than the elapse of a predetermined period.

  Note that the mobile station apparatus 1 described above has a computer system therein. Each process in the mobile station apparatus 1 described above is stored in a computer-readable recording medium in the form of a program, and the above process is performed by the computer reading and executing the program. Here, the computer-readable recording medium refers to a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, and the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

DESCRIPTION OF SYMBOLS 1,71 ... Mobile station apparatus 10, 22 ... Transmission part 11 ... Determination part 12 ... Channel setting part 13, 21 ... Reception part 14, 23 ... Control part 15 ... Position information acquisition unit 16 ... storage unit 2 (2A, 2B) ... emergency transmission base station apparatus 72 (72A, 72B) ... constant transmission base station apparatus 82 (82A, 82B) ... emergency transmission base Station apparatus 100 ... Radio communication system

Claims (10)

A transmitter that transmits a predetermined synchronization signal using a predetermined channel;
A determination unit that determines whether or not the loopback signal for the synchronization signal has been received by the predetermined channel from an emergency transmission base station device that does not regularly transmit a radio signal;
When receiving the return signal, a channel setting unit that sets the channel that has received the return signal as a communication channel;
With
The determination unit
A mobile station apparatus, characterized in that it determines that a loopback signal has been received from the emergency transmission base station apparatus, on condition that the reception strength of the loopback signal is equal to or greater than a predetermined threshold. The transmitter is
A channel switching identifier for determining that the emergency transmission base station apparatus stops all transmissions at the next timing of transmission of the return signal by the emergency transmission base station apparatus with respect to the synchronization signal is multiplexed with the synchronization signal. The mobile station apparatus according to claim 1, wherein the mobile station apparatus transmits the mobile station apparatus. The transmitter is
Sequentially transmitting the synchronization signal for each of a plurality of channels;
The channel setting unit
The mobile station apparatus according to claim 1 or 2, wherein any one of the channels that have received the return signal for each of the synchronization signals is set as a communication channel. The transmitter is
In the process of sequentially transmitting the plurality of synchronization signals,
When it is determined that the determination unit has initially received the return signal from the emergency transmission base station device, the transmission of the synchronization signal is stopped at that time,
The channel setting unit
The mobile station apparatus according to claim 3, wherein a channel that first receives the return signal is set as a communication channel. The determination unit
Further, the reception strength of each of the return signals for the plurality of synchronization signals is stored,
The channel setting unit
The mobile station apparatus according to claim 3, wherein the channel having the highest reception strength is set as a communication channel. A location information acquisition unit that acquires location information of the device itself;
A storage unit for storing in advance base station information stored in association with the location information of the emergency transmission base station device and the channel used by the emergency transmission base station device;
With
The transmitter is
The mobile station apparatus according to any one of claims 1 to 5, wherein a synchronization signal is transmitted for a channel used by an emergency transmission base station apparatus existing within a predetermined range from the position of the own apparatus. . The transmitter is
The mobile station apparatus according to any one of claims 1 to 6, wherein the synchronization signal is transmitted at any timing at least every predetermined period and every predetermined moving distance. The mobile station device
A transmitter that transmits a predetermined synchronization signal using a predetermined channel;
A determination unit that determines whether or not there is a return signal for the synchronization signal from an emergency transmission base station device that does not regularly transmit a radio signal to the mobile station device using the predetermined channel; ,
When receiving the return signal, a channel setting unit that sets the channel that has received the return signal as a communication channel;
With
The emergency transmission base station device
A wireless communication system, comprising: a transmission unit that transmits a return signal using a channel used by the received synchronization signal when the synchronization signal is received. The mobile station device transmits a predetermined synchronization signal using a predetermined channel,
When the emergency transmission base station apparatus that does not regularly transmit radio signals to the mobile station apparatus receives the synchronization signal, it transmits a loopback signal using the channel used by the received synchronization signal,
When the mobile station apparatus determines whether or not a loopback signal is received for the synchronization signal from the emergency transmission base station apparatus using the predetermined channel, and when the loopback signal is received A wireless communication method comprising: setting a channel that has received the return signal as a communication channel. A computer of a mobile station apparatus that establishes communication with an emergency transmission base station apparatus that does not regularly transmit an empty line signal to the mobile station apparatus.
A transmission means for transmitting a predetermined synchronization signal using a predetermined channel;
Determining means for determining whether or not there is reception of a return signal for the synchronization signal from the emergency transmission base station device using the predetermined channel;
If the return signal is received, channel setting means for setting the channel that has received the return signal as a communication channel;
A program characterized by functioning as

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