External battery and satellite communication terminal

A device that can realize satellite communication with a popularized mobile phone in a case a large number of users communicate at a same time such as in a case where disaster strikes and the like. An external battery for charging a mobile phone includes a satellite antenna for performing satellite communication via a satellite communication channel and a satellite communication unit which causes the mobile phone to perform the satellite communication via the satellite antenna. The mobile phone and the external battery are connected with a cable and the like, and thereby a satellite communication terminal is configured.

TECHNICAL FIELD

The present invention relates to an external battery for charging a mobile communication terminal such as a mobile phone and the like. In particular, the present invention relates to an external battery having a function to cause a mobile communication terminal to perform satellite communication. Further, the present invention relates to a satellite communication terminal having the mobile communication terminal and the external battery.

BACKGROUND ART

In a case of contingencies such as disaster like earthquake in urban area, it is desired to promptly perform a rescue request and safety confirmation.

Presently, a lot of people have and always carry a mobile phone. Therefore, it is considered that a rescue request and safety information can be sent from the mobile phone to a disaster center and the like. However, in a case where disaster like earthquake occurs in urban area, a mobile communication channel might not be used due to the destruction of a base station and the like.

Patent literature 1 describes, in a case where disaster strikes, safety confirmation information can be collected from the mobile phones using the satellite communication channel. This makes possible to collect safety confirmation information even when the mobile communication channel cannot be used due to the destruction of the base station and the like.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

As described in Patent Literature 1, if the satellite communication channel can be used in a case where disaster strikes, a rescue request and safety confirmation can be carried out promptly.

However, from a practical viewpoint, the frequency band is limited for the mobile communication terminal of the mobile phone and the like to perform the satellite communication using the satellite communication channel. Therefore, in a case where disaster strikes and the like, it is impossible to assign the frequency band sufficient to perform the satellite communication by the mobile communication terminal of a large number of users at the same time.

If the sufficient frequency band is not assigned, the mobile phone is required to have a large amount of electric power to obtain the transmission/reception power and a large antenna to obtain high antenna gain for performing the satellite communication. However, the popularized mobile phone is required to be downsized, so that the battery with large power capacity and the large antenna cannot be mounted. Therefore, it is difficult to perform the satellite communication using the popularized mobile phone.

The present invention aims to achieve the satellite communication using the popularized mobile communication terminal in a case where a large number of users communicate at the same time such as in a case where disaster strikes and the like.

Solution to Problem

According to the present invention, an external battery that charges a mobile communication terminal includes:

an electricity storage unit that stores electric power;

a charging unit that supplies the electric power stored in the electricity storage unit to the mobile communication terminal to charge the mobile communication terminal;

a satellite antenna to be used when performing satellite communication via a satellite communication channel; and

a satellite communication unit that causes the mobile communication terminal to perform the satellite communication of message including a self-position via the satellite antenna.

Advantageous Effects of Invention

The external battery related to the present invention includes not only a function to charge the mobile communication terminal, but also a function to cause the mobile communication terminal to perform the satellite communication.

Since the external battery does not have a number of functions like the mobile communication terminal, it is possible to mount the battery with large power capacity and a large antenna, while suppressing the largeness. Therefore, the external battery is combined with the mobile communication terminal, and thereby, in a case where a large number of users communicate at the same time such as in a case where disaster strikes and the like, the satellite communication can be achieved by the popularized mobile communication terminal.

Further, it is common to carry the external battery with the mobile communication terminal. Therefore, in a case of contingencies such as where disaster strikes and the like, the external battery is carried with the mobile communication terminal, and thus a rescue request and the like can be performed.

DESCRIPTION OF EMBODIMENTS

FIG. 1is a configuration diagram of a satellite communication terminal100related to a first embodiment.

The satellite communication terminal100includes a mobile phone10(mobile communication terminal) such as smartphones and an external battery20for charging the mobile phone10. The mobile phone10and the external battery20are connected via a cable30.

The mobile phone10includes an electricity storage unit11, a mobile antenna12, a mobile communication unit13, a control unit14, an input unit15, an output unit16, and a connection unit17.

The electricity storage unit11is an electric storage device such as lithium-ion battery for storing electric power to drive the mobile phone10. The mobile antenna12is an antenna for performing communication (mobile communication, hereinafter) by a mobile communication channel which passes through a ground-based base station and the like. The mobile communication unit13is a function to perform the mobile communication via the mobile antenna12. The control unit14is a processing device such as CPU which carries out various control according to inputs from the input unit15and the like. The input unit15is an input device such as a keyboard, a microphone, and the like for inputting character data, voice data, and the like. The output unit16is an output device such as an LCD, a speaker, and the like for outputting character data, voice data, and the like. The connection unit17is a connecting device for connecting to the electric power source and instruments such as the external battery20; a cable30of USB standard and the like which can be used for both of supplying the electric power and transmitting signals is connected.

The external battery20includes an electricity storage unit21, a satellite antenna22, a charging unit23, a satellite communication unit24, and a selection unit25.

The electricity storage unit21is an electric storage device such as lithium-ion battery which stores electric power for charging the mobile phone10as well as for driving the external battery20. The satellite antenna22is an antenna for performing communication (satellite communication, hereinafter) using the satellite communication channel via quasi-zenith satellites. The charging unit23is a function to supply the electric power stored in the electricity storage unit21to the mobile phone10and to charge the electricity storage unit11of the mobile phone10. The satellite communication unit24is a function to cause the mobile phone10to perform the satellite communication via the satellite antenna22. The selection unit25is a function to make a selection of at least either of a charge mode for causing the charging unit23to charge and a communication mode for causing the satellite communication unit24to perform the satellite communication according to inputs from the input unit15and the like.

Here, functions explained above may be implemented by, for instance, software and the like. In this case, the software for implementing the functions may be stored in memory devices such as ROM, RAM or the like, and read and executed by the processing device such as CPU. Further, the functions may be implemented not by software but by circuits, devices, and the like.

FIG. 2is a flowchart showing an operation of the satellite communication terminal100related to the first embodiment.FIG. 2shows the operation of a case where the external battery20is connected to the connection unit17.

Upon connecting the external battery20to the connection unit17, the selection unit25is started; the selection unit25instructs the mobile phone10to select either of the charge mode and the communication mode (S11). Then, the control unit14receives the instruction, outputs the message to the output unit16(for instance, displays the message on LCD), and prompts the user to select either of the charge mode and the communication mode (S12). Then, according to the operation of the user, the input unit15selects at least either of the charge mode and the communication mode (S13).

If the charge mode is selected at S13, the charging unit23is started by the control unit14, the charging unit23supplies the electric power stored in the electricity storage unit21to the mobile phone10to charge the electricity storage unit11(S14).

On the other hand, if the communication mode is selected at S13, the satellite communication unit24is started by the control unit14, the satellite communication unit24connects the mobile phone10to the satellite communication channel via the satellite antenna22(S15). The mobile phone10, when connected to the satellite communication channel, using the input unit15and the output unit16, performs the satellite communication of transmission/receipt of the message with the predetermined number of characters or less including information showing a self-position and the like.

Here, at the normal time where the external battery20is not connected to the connection unit17of the mobile phone10, the mobile phone10works as a general mobile phone. That is, at the normal time, the mobile communication unit13is started by the control unit14, and the mobile phone10is connected to the mobile communication channel via the mobile antenna12. Then, voice call, transmission/receipt of electronic mail, browsing websites, downloading application software and the like are carried out using the input unit15and the output unit16.

Further, even when being charged at S14, the mobile phone10also works as the general mobile phone.

Here, the mobile phone10is not a particular one for performing the satellite communication, but a popularly used mobile phone. The general mobile phone10has been required to be multi-functional and as well to be downsized. Therefore, the electricity storage unit11cannot be enlarged; and it is impossible to store the sufficient electric power to perform the satellite communication using the narrow communication band in the electricity storage unit11. Further, a large antenna for performing the satellite communication cannot be mounted on the mobile phone10.

However, the external battery20is not required to be multi-functional or downsized like the mobile phone10. Therefore, the electricity storage unit21can be enlarged to some extent, which enables to store the sufficient electric power to perform the satellite communication using the narrow communication band. Even if the electricity storage unit21cannot store the sufficient electric power, the electric power stored in the electricity storage unit11and the electric power stored in the electricity storage unit21can be combined to make the sufficient electric power. Further, a large antenna (satellite antenna22) for performing the satellite communication can be mounted on the external battery20.

As discussed above, in the satellite communication terminal100related to the first embodiment, the satellite antenna22and the like is mounted on the external battery20, so that the satellite communication is achieved by working the mobile phone10and the external battery20together.

By the above, a weak spot that only the popularized mobile phone10cannot supply sufficient transmission/reception power and antenna gain is supplemented by the external battery20, which enables the satellite communication by the popularized mobile phone10.

As a result of this, in a case where disaster strikes and the like, a large number of users try to communicate at the same time, which enables the satellite communication by the popularized mobile phone10. In particular, since the transmission/reception power and the antenna gain are high, the satellite communication is possible even in a circumstance where obstacles exist such as woods or nibbles. Further, even in a case where the satellite communication itself is difficult due to nibbles or shielding, it is possible to provide a rescue signal for rescue operation by a search party.

Here, it is desired to carry the external battery20with the mobile phone10. Therefore, even if a large electricity storage unit21is desired, it is not possible to make it too large to carry. Similarly, even if a large antenna is desired, it is not possible to make it too large to carry.

However, since the external battery20is not multi-functional such as the mobile phone10, there is no need to mount many components on the external battery20. Further, the external battery20is rarely manipulated by hand like the mobile phone10, and usually contained in a bag and the like. Therefore, if the external battery20and the mobile phone10are made to have similar size, it is possible to mount a larger electricity storage unit or a larger antenna on the external battery20.

Further, in the above explanation, a cable30that can be used for both of the power supply and the signal transmission is connected to the connection unit17. However, two cables of a cable for the power supply and a cable for the signal transmission can be connected to the connection unit17. Further, in case of the satellite communication, the cable30is not connected to the connection unit17, but wireless connection can be achieved.

Further, in the above explanation, in case of the satellite communication, messages with the predetermined number of characters or less are transmitted/received. However, it is also possible to transmit/receive voice calls or image data. However, as described above, since a sufficient frequency band is not assigned, the communication with large data amount might be difficult. Therefore, the communication with suppressed data amount is desired.

Further, in order to work the popularized mobile phone10and the external battery20together, additional functions may be required in the mobile phone10. In this case, for instance, application software for implementing the additional functions can be downloaded from a predetermined website and the like to be installed by the mobile phone10. Obviously, not limited to the above, additional functions may be introduced to the mobile phone10in some manners.

Further, in the above explanation, quasi-zenith satellites are used for the satellite in the satellite communication. Not limited to this, the satellite communication can be mediated by another satellite such as a geostationary satellite. However, since the quasi-zenith satellite is located at the zenith with a high elevation angle, it is possible to secure the communication channel under a circumstance where the communication eyesight to the geostationary satellite is interrupted due to the mountain shade or building shade and the like. Therefore, a rescue request can be achieved from mountain area or urban area.

Further, an S band, for example, is used as the frequency band for the satellite communication. The S band is the frequency band which is allowed to use by the mobile communication among the satellite communication channels, and further, it is possible to obtain sufficiently effective transmission/receipt sensitivity by the antenna with a dimension of around 50 mm×50 mm×5 mm for the mobile communication. Therefore, it is easy to implement this antenna on the external battery20.

Further, in the above explanation, on connecting to the satellite communication channel, the mobile phone10performs the satellite communication such as the transmission/reception of the messages and the like.

Here, in case of sending a message, when the external battery20receives a transmission instruction from the mobile phone10, the instructed message is sent via the satellite communication channel. That is, the external battery20works by receiving the instruction from the mobile phone10.

On the other hand, in case of receiving the message, when receiving the message via the satellite communication channel, the external battery20sends the message to the mobile phone10. That is, the external battery20, on receiving the message via the satellite communication channel, sends the message to the mobile phone10even when no instruction from the mobile phone10is received to obtain the message. Therefore, it is unnecessary for the mobile phone10to periodically check if the external battery20receives the message or not; and the mobile phone10may become sleep state. Therefore, the power consumption of the mobile phone10can be suppressed.

Here, when the external battery20sends the message to the mobile phone10, if the mobile phone10is in the sleep state, the external battery20may activate the mobile phone10and send the message to the mobile phone10. For instance, the above operation can be performed if the mobile phone10is set to receive the activation signal from the external battery20even when the mobile phone10is in the sleep state.

Further, in the above explanation, either of the charge mode and the communication mode is selected. However, the charge mode and the communication mode can be selected at the same time. In this case, the satellite communication can be performed by the mobile phone10, while the electricity storage unit11is being charged. Therefore, the satellite communication can be performed by the mobile phone10even if the electricity storage unit11stores less amount of electric power.

Further, in the above explanation, the mobile phone10is an example of a mobile communication terminal. However, another type of communication terminal other than the mobile phone10may be used as long as it is carried by the user.

In the first embodiment, it is explained that the user is prompted to select the charge mode and the communication mode. In the second embodiment, the charge mode and the communication mode can be selected automatically according to whether or not an emergency broadcast signal is received from the satellite.

A part being different from the first embodiment will be mainly explained in the second embodiment.

In the first embodiment, at S11to S13ofFIG. 2, the user is prompted to select the charge mode or the communication mode.

On the contrary to this, in the second embodiment, when the external battery20is connected, according to whether or not a satellite communication unit24receives the emergency broadcast signal from the satellite, a selection unit25selects the charge mode or the communication mode. Specifically, the selection unit25, when the external battery20is connected, selects the charge mode if the emergency broadcast signal is not received, and selects the communication mode if the emergency broadcast signal is received.

Further, if the external battery20is connected to the mobile phone10and the charge mode is being selected, when the satellite communication unit24receives the emergency broadcast signal, the selection unit25switches the charge mode to the communication mode.

For instance, in a case where disaster strikes and the like, the emergency broadcast signal is sent from the satellite to make the communication mode be automatically selected. Because, in a case where disaster strikes and the like, there may be a case where the operation to select the communication mode is bothersome or difficult.

As discussed above, in the satellite communication terminal100related to the second embodiment, according to whether or not the emergency broadcast signal is received from the satellite, the charge mode or the communication mode can be selected automatically. Therefore, the user does not need to do the bothersome operation, which improves the convenience.

Here, the external battery20may be provided with a display device such as an LCD, and when the emergency broadcast signal is received, the receipt of the emergency broadcast signal may be displayed to notify the user. Further, the external battery20may be provided with a speaker, and when the emergency broadcast signal is received, the receipt of the emergency broadcast signal may be notified to the user by sound.

Further, there may be a case where without receiving the emergency broadcast signal, it is necessary to perform the satellite communication by some reason. Therefore, for instance, the charge mode and the communication mode may be switched according to the operation of the user from an input unit15.

In the second embodiment, according to whether or not the emergency broadcast signal is received from the satellite, the charge mode or the communication mode can be selected automatically. In the third embodiment, it will be explained that the charge mode or the communication mode can be selected automatically according to whether or not the mobile communication can be performed.

In the third embodiment, a part being different from the first embodiment will be mainly explained.

In the first embodiment, at S11to S13ofFIG. 2, the user is prompted to select the charge mode or the communication mode.

On the contrary to the above, in the third embodiment, when the external battery20is connected, the selection unit25selects the charge mode or the communication mode according to whether or not the mobile phone10can perform the mobile communication via the mobile antenna12. Specifically, the selection unit25, when the external battery20is connected, if the mobile communication is available, selects the charge mode, and if the mobile communication is not available, selects the communication mode.

Further, when the external battery20is connected to the mobile phone10, and when the charge mode is being selected, if the state in which the mobile communication is not available continues for a certain time period or more, it is also possible to switch to the communication mode.

The state in which the mobile communication is not available is, for instance, a case where electrical wave for the mobile communication cannot be received continuously for equal to or greater than a certain time period or where the mobile communication channel is in congestion state.

The above control is performed because, in a case where the mobile communication is available, the necessity of the satellite communication is low, and thus the user does not need to be prompted to select the charge mode or the communication mode. In particular, in a case where disaster strikes and the like, there may be a case where the operation to select the communication mode is bothersome or difficult.

As discussed above, in the satellite communication terminal100related to the third embodiment, the charge mode or the communication mode can be selected automatically according to the state of the mobile communication. Therefore, the user does not need to do the bothersome operation, which improves the convenience.

Here, even if the mobile communication is available, the satellite communication might be necessary for some reason. Therefore, for instance, the charge mode and the communication mode can be switched according to the operation of the user from the input unit15.

The fourth embodiment will explain that authentication is performed at the time of the satellite communication.

In the fourth embodiment, a part being different from the first embodiment will be mainly explained.

FIG. 3is a configuration diagram of the satellite communication terminal100related to the fourth embodiment.

The satellite communication terminal100shown inFIG. 3includes, in addition to the configuration of the satellite communication terminal100shown inFIG. 1, an authentication unit26in the external battery20.

The authentication unit26carries out user authentication by making the user enter an ID and a password and the like.

FIG. 4is a flowchart showing an operation of the satellite communication terminal100related to the fourth embodiment.FIG. 4shows the operation when the external battery20is connected to the connection unit17; and similarly to the first embodiment, when the external battery20is connected, the user is prompted to select the charge mode or the communication mode.

The operations from S21to S24are the same as the ones from S11to S14shown inFIG. 2, and the explanation will be omitted.

When the communication mode is selected at S23, the authentication unit26instructs the mobile phone10to enter the ID and password (S25). Then, the control unit14receives the instruction, outputs the message to the output unit16, and prompts the user to enter the ID and password (S26). According to the operation of the user, the input unit15inputs the ID and password (S27). The authentication unit26carries out the user authentication based on the entered ID and password and the ID and password which have been previously registered (S28).

If the user authentication succeeded at S28, the satellite communication unit24is started by the control unit14, the satellite communication unit24connects the mobile phone10to the satellite communication channel via the satellite antenna22(S29). On the other hand, if the user authentication failed at S28, the satellite communication is not allowed and the mobile phone10is not connected to the satellite communication channel.

In the above explanation, if the user authentication failed, the satellite communication is not allowed. However, in case of emergency such as when a rescue request is issued, there may be a case where it is better that the satellite communication is made available regardless of whether or not the user authentication succeeded. Then, if the user authentication failed, the satellite communication may be made possible to communicate with only a predetermined communication partner.

Further, in the above explanation, similarly to the first embodiment, when the external battery20is connected, the user is prompted to select the charge mode or the communication mode. However, similarly to the second embodiment, when the external battery20is connected, the charge mode or the communication mode can be selected according to the state of the mobile communication. In this case, after the communication mode is selected, until the user authentication is carried out, the satellite communication can be limited with only a predetermined communication partner; and if the user authentication succeeds, the satellite communication can be performed with an arbitrary communication partner.

As discussed above, in the satellite communication terminal100related to the fourth embodiment, if the user authentication succeeds, the mobile phone10is allowed to perform the satellite communication. Therefore, it is possible to prevent a person other than the registered user from performing the satellite communication.

On the other hand, a person other than the registered user can perform the satellite communication with the predetermined communication partner. Therefore, anyone can perform a rescue request and the like in case of emergency.

Further, the user authentication is carried out, thereby specifying a user who has performed the satellite communication. Therefore, the specified user can be charged for the satellite communication. Here, the charging can be paid in arrears or in advance.

Further, the authentication unit26may carry out, not limited to the authentication using the ID and password, the user authentication by another method such as the biometric authentication.

The fifth embodiment will explain that the external battery20further includes an antenna that receives positioning signals from the satellites such as the quasi-zenith satellites.

In the fifth embodiment, a part being different from the first embodiment will be mainly explained.

FIG. 5is a configuration diagram of the satellite communication terminal100related to the fifth embodiment.

As for the configuration of the satellite communication terminal100shown inFIG. 5, in addition to the configuration of the satellite communication terminal100shown inFIG. 1, the mobile phone10includes a positioning unit18, and the external battery20includes a signal reception unit27.

The positioning unit18is a function to specify the location of the satellite communication terminal100based on the positioning signal sent from the satellite. The positioning signal includes a positioning supplemental signal that is used for measuring the distance and a positioning reinforcing signal including information that contributes the improvement of the accuracy. Here, the positioning signal may include both or either of the positioning supplemental signal and the positioning reinforcing signal.

The signal reception unit27is an antenna that receives the positioning signals sent from the satellites such as the quasi-zenith satellites. In particular, the signal reception unit27is an antenna that can receive the positioning signals of a plurality of frequency bands. For instance, the signal reception unit27is an antenna that can receive the L1 band and the L2 band, or an antenna that can receive the L1 band and the L5 band.

FIG. 6is a flowchart showing an operation of the satellite communication terminal100related to the fifth embodiment.FIG. 6shows the operation of a case where the external battery20is connected to the connection unit17; similarly to the first embodiment,FIG. 6shows the operation of prompting the user to select between the charge mode and the communication mode in a case where the external battery20is connected.

The operations from S31to S35are the same as the ones from S11to S15shown inFIG. 2, and thus the explanation will be omitted.

In a case where the communication mode is selected at S33, subsequent to S35, the signal reception unit27is started by the control unit14, the signal reception unit27receives the positioning signal and sends the signal to the mobile phone10(at S36). Then, the positioning unit18specifies the location of the satellite communication terminal100based on the positioning signal received by the signal reception unit27(S37). The location information showing the location of the specified satellite communication terminal100may be sent to the communication partner via the satellite communication according to an input from the input unit15.

As discussed above, in the satellite communication terminal100related to the fifth embodiment, the external battery20includes the signal reception unit27. In the disaster center and the like which receives the rescue request, it is necessary to specify the location of the requester. The external battery20is provided with the signal reception unit27, which enables to specify the location of the requester, and the specified location can be informed to the disaster center and the like.

However, the antenna provided to the popularized mobile phone10, since a large antenna cannot be mounted due to the downsizing request and the like for the mobile phone10, is a one frequency antenna. Therefore, the positioning accuracy is low.

Further, the popularized mobile phone10specifies the location by an assisted GPS. In a case where disaster strikes and the like, when the ground station is damaged, the assisted GPS might become impossible to use. Then, continuous positioning by the satellite becomes necessary, which requires frequent receipt of positioning signals. As a result of this, the electric power of the mobile phone10is consumed in a short time.

On the contrary to the above, in a case where the external battery20is provided with the signal reception unit27, a large antenna can be used, and thus the signal reception unit27can receive the positioning signals of a plurality of frequency bands. Therefore, the positioning accuracy can be improved. Further, the positioning signal is received by the external battery20, so that the power consumption of the mobile phone10can be suppressed.

In the above explanation, the positioning unit18provided to the mobile phone10specifies the location based on the positioning signal. However, the function to specify the location based on the positioning signal may be included in the external battery20, and the location may be specified by the external battery20. The above operation can further suppress the power consumption of the mobile phone10.

Further, in the above explanation, when the communication mode is selected, the signal reception unit27receives the positioning signal. However, regardless of whether or not the communication mode is selected, when the positioning accuracy obtained by the configuration of the mobile phone10itself (the positioning function included in the mobile phone10) becomes low, the mobile phone10may issue a request to start the signal reception unit27. In another way, in a case where the remaining power of the electricity storage unit11becomes equal to or less than a certain amount, the mobile phone10may issue a request to start the signal reception unit27. Then, the signal reception unit27can receive the positioning signal in a case where the starting request is issued from the mobile phone10.

The case where the positioning accuracy obtained by the configuration of the mobile phone10itself becomes low is, for instance, when the assisted GPS cannot be used, that is, the positioning information cannot be obtained via the ground station, and the like.

Further, the signal reception unit27, on receiving the positioning signal, even if the instruction to obtain the positioning signal is not received from the mobile phone10, sends the positioning signal to the mobile phone10. Therefore, the mobile phone10does not need to periodically check whether or not the external battery20receives the positioning signal, and the mobile phone10can be in the sleep state. Therefore, the power consumption of the mobile phone10can be suppressed.

The sixth embodiment will explain that the external battery20further includes a function to measure biological information such as blood pressure, pulsation, blood glucose level and the like.

FIG. 7is a configuration diagram of a satellite communication terminal100related to the sixth embodiment.

The satellite communication terminal100shown inFIG. 7includes, in addition to the configuration of the satellite communication terminal100shown inFIG. 1, a measurement unit28in the external battery20.

The measurement unit28is a measurement device to measure biological information such as blood pressure, pulsation, blood glucose level and the like.

For instance, the user suffering from disease, in a case where disaster strikes and the like, the biological information is measured by the measurement unit28and sent to the disaster center via the satellite communication. The above operation enables to confirm the status of the user's disease at the disaster center, and an appropriate treatment can be taken. Here, in a case where an abnormal acceleration is detected by acceleration information obtained by processing the positioning signal, it is also possible to react similarly by treating the abnormal acceleration as accident detection information; at this time, it is needless to say that it can be the starting request from the sleep state.

Here, the measurement unit28may previously store the user's personal hospital and the like as a destination of the information. In this case, the biological information is sent not to the disaster center, but to the destination registered previously; and thereby it is possible to check the status of user's disease more appropriately.

As discussed above, in the satellite communication terminal100related to the sixth embodiment, the satellite communication terminal100includes the measurement unit28. Based on the biological information measured by the measurement unit28, it is possible to understand the status of the user's disease, and to go to rescue the user with necessary instruments and the like.

Here, not limited to a case where disaster strikes, but also at the normal time, the biological information measured by the measurement unit28can be sent to the user's personal hospital, and thereby an ambulance can be deployed.

The seventh embodiment, it will be explained that route information showing an escape route and the like is stored in the external battery20.

In the seventh embodiment, a part being different from the first embodiment will be mainly explained.

FIG. 8is a configuration diagram of a satellite communication terminal100related to the seventh embodiment.

The satellite communication terminal100shown inFIG. 8includes, in addition to the configuration of the satellite communication terminal100shown inFIG. 1, a memory unit29in the external battery20.

The memory unit29is a memory device which stores map information, route information showing an escape route for a case where disaster strikes and the like, information required for securing lifelines, and the like.

The satellite communication terminal100is used at the time of contingencies such as a case where disaster strikes and the like. Therefore, the information required in a case where disaster strikes and the like is previously stored, and outputted from the output unit16of the mobile phone10.

Here, at the normal time, the map information, the route information, the information required for securing lifelines, and the like can be obtained from a predetermined website, etc. via the mobile communication or the satellite communication, and such information can be stored in the memory unit29.

As discussed above, the satellite communication terminal100related to the seventh embodiment stores the information required in a case where disaster strikes and the like in the external battery20. Therefore, in a case where disaster strikes and the like, necessary information can be obtained without performing the communication.

The eighth embodiment will explain a satellite communication system200using the satellite communication terminal100that has been explained in the first through sixth embodiments.

FIG. 9is a configuration diagram of the satellite communication system200related to the eighth embodiment.

The satellite communication system200includes a satellite communication terminal100, a quasi-zenith satellite110, a quasi-zenith satellite antenna station120, a quasi-zenith satellite operation control station130, and a disaster center140.

The satellite communication terminal100is the one which has been explained in the first to fifth embodiments. The quasi-zenith satellite110is a satellite which stays over a particular area for a long time and takes the quasi-zenith orbit. The quasi-zenith satellite antenna station120is a facility settled on the ground having an antenna for transmitting/receiving data to/from the quasi-zenith satellite3. It is a facility which relays data sent/received by the antenna of the quasi-zenith satellite antenna station120. The disaster center140is a facility which receives the rescue requests and collects the safety information.

In a case where disaster strikes and the like, the satellite communication terminal100communicates with the disaster center140through the satellite communication via the quasi-zenith satellite110, the quasi-zenith satellite antenna station120, and the quasi-zenith satellite operation control station130. Then, the rescue request and the safety information are sent to the satellite communication terminal100.

For instance, in a case where the rescue is requested, the satellite communication terminal100conveys the status of the site (for instance, the number of injured persons or the conditions of the injured), not only requests the rescue, to the disaster center140. Further, from the disaster center140, the information such as within how many minutes the rescue could reach the site, how to do first aid and the like is conveyed to the satellite communication terminal100.

Here, in the above explanation, the satellite communication system200which requests the rescue and the like using the satellite communication terminal100has been discussed. Here, COSPAS-SARSAT is known as a system which requests the rescue using the satellite communication channel.

In this system, when a beacon transmitter which is called E-PIRB (Emergency Position Indicating Radio Beacon) mounted on a ship takes water because of a ship accident and the like, a signal of the rescue signal is issued from the beacon transmitter. The issued signal is detected by the geostationary satellite, and circular orbit satellites measure the location of the issued signal. By this operation, the occurrence of the ship accident and the location of the accident are specified, and immediate rescue activities can be implemented.

This search and rescue system has been also applied to the use on the ground. For instance, in a case of distress in mountaineering and the like, when a mountain climber issues a signal of rescue request by a PLB (Personal Locator Beacon), the issued signal is detected by the geostationary satellite, and circular orbit satellites measure the location of the issued signal.

In this search and rescue system, only the transmitter issues the signal, and there is no means to convey additional information such as the status of the accident site. Further, in this search and rescue system, the signal is sent unidirectionally from the accident site, and the information cannot be sent from the rescue side to the accident site.

Further, E-PIRB and PLB are dedicated terminals for rescue request. This kind of dedicated terminals for rescue request are carried only at special occasion such as mountain climbing and the like, and such terminals are not always carried. Therefore, in a case of contingencies where a disaster like earthquake occurs in urban area, such terminals rarely be carried; and such terminals never be used as a terminal for the rescue request at the time of contingencies.

On the contrary to the above, in the satellite communication system200, the satellite communication terminal100can convey the additional information, and the bi-directional communication can be performed with the disaster center140. Further, the mobile phone10and the external battery20which form the satellite communication terminal100are to be always carried.

Further, in the above explanation, the transmission/reception power and the antenna gain of the mobile phone10are increased, and thereby enabling the satellite communication in the narrow communication band. Without increasing the transmission/reception power and the antenna gain of the mobile phone10, the satellite communication can be performed by enlarging the antenna at the satellite side.

However, if the antenna at the satellite side is enlarged, the transmission area of the signals from the satellite becomes narrow, and thus the satellite communication area becomes also narrow. Further, as explained in the fifth embodiment, in a case where the satellites send the positioning signals, the positioning accuracy based on the positioning signals becomes low.

Therefore, it is difficult to enlarge the antenna at the satellite side to configure the satellite communication system200.

Up to the above, the embodiments of the present invention have been explained; among the embodiments, two or more embodiments can be combined and implemented. In another way, among these embodiments, one embodiment can be partially implemented. In another way, among these embodiments, two or more embodiments can be partially combined and implemented. Here, the present invention is not limited to these embodiments, but various modifications can be done according to the necessity.

REFERENCE SIGNS LIST