Electronic apparatus capable of executing wireless communication, and wireless communication control method used in the electronic apparatus

【0001】

[Technical field to which the invention belongs]

The present invention relates to an electronic device used as a mobile station, such as a mobile information terminal and an in-vehicle electronic device, and a wireless communication control method used in the electronic device.

【0002】

[Conventional technology]

Conventionally, a car navigation device has been known as a typical in-vehicle electronic device mounted on a car and used.

【0003】

The car navigation device detects the position of the own vehicle using a position detection device such as GPS (Global Positioning System), and searches the map database for a map around the position of the own vehicle and displays it on the screen. Guidance and route guidance to the destination.

【0004】

Further, recently, a car navigation device having a function of displaying various incidental information stored in a map database as well as road guidance and route guidance has been developed.

【0005】

As a car navigation device capable of displaying such incidental information, information on facilities such as restaurants and gas stations is stored in advance in a map database, and facilities around the vehicle position are searched from the map database as needed. Is known (see, for example, Patent Document 1).

【0006】

[Patent Document 1]

Japanese Unexamined Patent Publication No. 2002-221430 (pages 7-8) [0007]

[Problems to be Solved by the Invention]

However, in the method using the incidental information registered in advance in the map database, it is practically difficult to present the details of the services currently provided in facilities such as restaurants and gas stations to the user in real time. ..

【0008】

Therefore, it is desired to realize a mechanism for acquiring necessary information from the outside through the Internet or the like.

【0009】

In order to acquire necessary information from the outside in real time, it is necessary to use a wireless communication method having a high communication speed, such as a wireless LAN conforming to the IEEE 802.11 standard.

【0010】

However, at present, there are few places where base stations (or access points) compatible with wireless LAN are installed. Furthermore, the area of the communication area covered by one base station compatible with wireless LAN is, for example, a radius of about 200 m, which is far larger than the communication area covered by the base station corresponding to a general mobile telephone system. narrow.

【0011】

Therefore, the wireless LAN can be used only in a specific area, and communication with the outside cannot be performed depending on the moving place of the automobile.

【0012】

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an electronic device and a wireless communication control method capable of executing wireless communication with the outside regardless of a moving place.

【0013】

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention comprises a first wireless communication means for executing wireless communication by the first wireless communication method and a second wireless communication means for executing wireless communication by the second wireless communication method. Is an electronic device that can be selectively used, and is a means for holding base station information regarding the locations of a base station corresponding to the first wireless communication method and a base station corresponding to the second wireless communication method. , A position detecting means for detecting the current position of the electronic device, and a wireless communication means to be used for communication with the outside based on the current position of the electronic device detected by the position detecting means and the base station information. Is provided with a switching means for switching between the first wireless communication means and the second wireless communication means.

【0014】

According to this electronic device, in order to execute wireless communication with the outside regardless of the location of movement, the wireless communication means to be used for communication with the outside based on the current position of the electronic device and the base station information. Switching is done automatically. Therefore, it is possible to communicate with the outside by using the optimum wireless communication method for each moving place.

【0015】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of an in-vehicle electronic device according to an embodiment of the present invention. The in-vehicle electronic device 11 is a system used by being mounted on an automobile. As shown in the figure, the vehicle-mounted electronic device 11 is provided with a system control unit 12, a CD / DVD drive device 13, and a storage device 14.

【0016】

The system control unit 12 is a processor that executes various information processing for controlling the operation of the in-vehicle electronic device 11, the navigation control unit 111 for executing the car navigation function, and the communication for executing the wireless communication function. It has a control unit 112. The communication control unit 112 functions as a gateway for connecting the in-vehicle electronic device 11 to an external IP network such as the Internet. All communication with the Internet is controlled by the communication control unit 112.

【0017】

Navigation control unit 111 The car navigation function is a function that guides the road and guides the route to the destination by displaying a map around the position of the own vehicle on the screen.

【0018】

The wireless communication function of the communication control unit 112 is a function for communicating with the outside via, for example, the Internet. This wireless communication function is used, for example, to receive content data such as service information about each facility around the position of the own vehicle from the Internet or the like. The service information is electronic information indicating the contents of services provided by each facility such as a restaurant, a gas station, a convenience store, a movie theater, a museum, a service area, an amusement park, and an amusement park.

【0019】

In-vehicle electronic devices 11 are provided with first to third wireless communication devices 26, 27, 28 in order to perform wireless communication with the outside. These wireless communication devices 26, 27, 28 are configured to execute wireless communication by different wireless communication methods. In wireless communication with the outside, the first to third wireless communication devices 26, 27, 28 are selectively used.

【0020】

The first wireless communication device 26 executes wireless communication by, for example, a wireless communication method (first wireless communication method) corresponding to the wireless LAN of the IEEE802.11 standard.

【0021】

The communication speed in this wireless LAN is, for example, 54 Mbps. The first wireless communication device 26 executes wireless communication with a base station (or an access point) corresponding to the wireless LAN. Each base station compatible with wireless LAN covers a range of about 100 m in radius from its location as a communication area (zone or cell).

【0022】

The second wireless communication device 27 and the third wireless communication device 28 perform wireless communication by a wireless communication method corresponding to different types of mobile telephone systems.

【0023】

Here, the second wireless communication device 27 corresponds to a wireless communication system (second wireless communication system) such as PHS (Personal Handy phone System) or PCS (Personal Communication System), and the third wireless communication device 27 is supported. It is assumed that the communication device 28 is compatible with a wireless communication method (third wireless communication method) such as 3GPP (3rd Generation Partnership Project), which is a standard for a third-generation wideband mobile phone system, for example. ..

【0024】

The second wireless communication device 27 executes wireless communication with a base station corresponding to the second wireless communication method. The communication speed is about 32 kbps to 128 kbps. Each base station corresponding to the second wireless communication method covers a range with a radius of about 500 m from its location as a communication area (zone or cell).

【0025】

The third wireless communication device 28 executes wireless communication with a base station corresponding to the third wireless communication method. The communication speed is about 384kbps. Each base station corresponding to the third wireless communication system covers a range of a radius of several km to a dozen km from its location as a communication area (zone or cell).

【0026】

The wireless communication environment of each of the first to third wireless communication methods differs depending on the current position of the vehicle in which the in-vehicle electronic device 11 is mounted. For example, in some positions, all of the first to third wireless communication methods can be used, whereas in other positions, only the third wireless communication method can be used.

【0027】

The communication control unit 112 sets the wireless communication device to be used for communication with the outside by the first to third wireless communication according to the wireless communication environment of each of the first to third wireless communication methods at the current vehicle position. It has a communication device switching function that automatically switches between devices 26, 27, and 28. This communication device switching function makes it possible to automatically select the most suitable wireless communication device for communication from the current vehicle position. The user does not need to be aware of the type of communication device used for communication with the outside.

【0028】

When the vehicle position is in a position where two or more wireless communication methods among the first to third wireless communication methods can be used, among the available wireless communication devices, based on a predetermined priority. The highest priority wireless communication device is selected.

【0029】

The priority order is predetermined from the viewpoint of, for example, communication speed, communication charge, and the like. In the following, the first wireless communication device 26 has the highest priority, the second wireless communication device 27 has the second priority, and the third wireless communication device 28 has the lowest priority. Let us assume a case.

【0030】

Further, the communication control unit 112 has a data buffer 201 for temporarily holding data to be transmitted / received to / from the outside in order to seamlessly switch communication devices during communication with the outside. When switching communication devices during communication with the outside, the physical connection between the wireless communication device currently used for communication with the outside and its communication partner (for example, a server on the Internet) is temporarily disconnected. However, immediately after that, the newly selected wireless communication device reconnects with the communication partner. Although the download of the content data from the server on the Internet is temporarily interrupted, the newly selected wireless communication device can continue to download the content data from the server. As a result, it is possible to switch the communication device without the user noticing that the connection with the server has been disconnected.

【0031】

The CD / DVD drive device 13 is a drive device for reading a map database stored therein from a storage medium such as a CD or DVD mounted on the CD / DVD drive device 13. The map database is a database that stores map information including maps and location information of various facilities. Further, this map database includes a base station information database used for the above-mentioned communication device switching function.

【0032】

The base station information database is a database that stores base station information regarding the location of the base station corresponding to each of the first to third wireless communication methods. The communication control unit 112 uses the vehicle position and the base station database to automatically select the most suitable wireless communication device for communication from the current vehicle position. Third wireless communication method Determines the wireless communication environment of each.

【0033】

The storage device 14 is composed of, for example, a hard disk drive (HDD), and various content data can be stored in the storage device 14. The map database can also be stored in the storage device 14 in advance. In this case, the system control unit 12 can read the necessary map information from the storage device 14 without using the CD / DVD drive device 13. By downloading the map database from a server on the Internet via wireless communication, the map information, base station information, and the like can be updated to the latest contents.

【0034】

The in-vehicle electronic device 11 further includes a GPS unit 16, a vehicle speed sensor 17, a gyro sensor 18, and a vehicle information detection unit 19. The GPS unit 16, the vehicle speed sensor 17, the gyro sensor 18, and the vehicle information detection unit 19 are connected to the system control unit 12 via the interface 20.

【0035】

The GPS unit 16 is a position detection device for detecting the current position (own vehicle position) of the own vehicle, and receives radio waves from a plurality of satellites via the GPS antenna 15 to determine the own vehicle position (latitude, longitude). Position.

【0036】

The vehicle speed sensor 17 and the gyro sensor 18 are sensors for detecting the traveling speed and the traveling direction of the own vehicle, respectively. The vehicle information detection unit 19 detects various vehicle information regarding, for example, that the vehicle has backed up or that the side brake has been stepped on.

【0037】

The in-vehicle electronic device 11 further includes a TV tuner 21, an audio input / output unit 22, a display device 23, a tablet controller 24, and an audio output interface 30.

【0038】

The TV tuner 21 is a device that receives various broadcast signals such as terrestrial broadcasting and satellite broadcasting and selects a station. The voice input / output device 22 is used to perform a voice control function that controls the operation of the in-vehicle electronic device 11 based on a voice input from the user, and voice guidance related to route guidance.

【0039】

The display device 23 is an in-vehicle monitor (LCD monitor) for presenting various information to the user, displays map information for car navigation, displays content data received by wireless communication devices 26 to 28, and is a TV tuner 21. It is used for displaying TV broadcast programs received by.

【0040】

The tablet controller 24 is an input device for instructing the system control unit 12 to execute various operations in response to a user operation. The tablet controller 24 is composed of a transparent coordinate detection device arranged on the display screen of the display device 23. As a result, the display screen of the display device 23 functions as a touch screen. The user can input various operation instructions by touching various buttons displayed on the touch screen with a finger. The audio output interface 30 is an interface for connecting the in-vehicle electronic device 11 and the audio device in the vehicle.

【0041】

Next, the communication device switching function of the communication control unit 112 will be described with reference to FIGS. 2 and 3.

【0042】

FIG. 2 shows an example of the arrangement of communication areas (zones or cells) of each of the first to third wireless communication methods in a certain area.

【0043】

As described above, the communication area per base station is the narrowest in the first wireless communication system (wireless LAN), the widest in the third wireless communication system (3GPP), and the second wireless communication system (PHS). ) Is in between.

【0044】

Now, as shown in FIG. 2, two communication areas A1 and A2 corresponding to the first wireless communication method (wireless LAN) are one communication area B1 corresponding to the second wireless communication method (PHS). It is assumed that the communication area B1 belongs to one communication area C1 corresponding to the third wireless communication system (3GPP).

【0045】

The communication area A1 is a communication area covered by the base station BS-A1 corresponding to the first wireless communication method (wireless LAN). The communication area A2 is a communication area covered by the base station BS-A2 corresponding to the first wireless communication method (wireless LAN).

【0046】

The communication area B1 is a communication area covered by the base station BS-B1 corresponding to the second wireless communication system (PHS). The communication area C1 is a communication area covered by the base station BS-C1 corresponding to the third wireless communication system (3GPP).

【0047】

It is assumed that the automobile 100 equipped with the in-vehicle electronic device 11 moves along the route shown by the arrow shown in the figure. In this case, the wireless communication environment of each of the first to third wireless communication methods at the current position of the automobile 100 changes as the automobile 100 moves. The communication control unit 112 determines the wireless communication environment of each of the first to third wireless communication methods corresponding to the current position of the automobile 100 by using the above-mentioned base station information database, and based on the determination result, determines the wireless communication environment. The wireless communication device to be used for wireless communication is dynamically switched as shown in Fig. 3.

【0048】

That is, when the current position of the automobile 100 is the point P1, the only wireless communication method that can be used is the third wireless communication method. Therefore, the communication control unit 112 uses the third wireless communication device (# 3) 28. select. At point P1, the third wireless communication device (# 3) 28 executes wireless communication with the base station BS-C1 corresponding to the third wireless communication system (3GPP).

【0049】

When the current position of the automobile 100 is the point P2, the available wireless communication methods are the second wireless communication method and the third wireless communication method. Since the second wireless communication method has a higher priority than the third wireless communication method, the communication control unit 112 selects the second wireless communication device (# 2) 27 corresponding to the second wireless communication method. .. At point P2, the second wireless communication device (# 2) 27 executes wireless communication with the base station BS-B1 corresponding to the second wireless communication system (PHS).

【0050】

When the current position of the automobile 100 is the point P3 or P4, the available radio communication methods are all of the first radio communication method, the second radio communication method, and the third radio communication method. Since the first wireless communication method has the highest priority, the communication control unit 112 selects the first wireless communication device (# 1) 26 corresponding to the first wireless communication method. At point P3, the first wireless communication device (# 1) 26 executes wireless communication with the base station BS-A1 corresponding to the first wireless communication method (wireless LAN). At point P4, the first wireless communication device (# 1) 26 executes wireless communication with the base station BS-A2 corresponding to the first wireless communication method (wireless LAN).

【0051】

When the current position of the automobile 100 is the point P5, the available wireless communication methods are the second wireless communication method and the third wireless communication method. Since the second wireless communication method has a higher priority than the third wireless communication method, the communication control unit 112 selects the second wireless communication device (# 2) 27 corresponding to the second wireless communication method. .. At point P5, the second wireless communication device (# 2) 27 executes wireless communication with the base station BS-B1 corresponding to the second wireless communication system (PHS).

【0052】

When the current position of the automobile 100 is the point P6, the only wireless communication method that can be used is the third wireless communication method. Therefore, the communication control unit 112 uses the third wireless communication method corresponding to the third wireless communication method. Select device (# 3) 28. At point P6, the third wireless communication device (# 3) 28 executes wireless communication with the base station BS-C1 corresponding to the third wireless communication system (3GPP).

【0053】

Figure 4 shows an example of a map database. The map database corresponds to a map information database that associates a map of each area with its location information, a facility information database that associates information about each facility with its location information, and each base station and its location information. Includes the attached base station information database.

【0054】

The base station information database is a database relating to the location of the base station corresponding to each of the first to third wireless communication methods. For example, as shown in the figure, the location (latitude, longitude) of the base station for each base station. , Base station type (base station ID, wireless communication method), and communicable area (eg zone radius). The base station ID is information that identifies the base station, and indicates, for example, the address of the base station.

【0055】

The communication control unit 112 searches the base station information database for a base station having a communication area covering the current position of the own vehicle, and the radio available at the current position according to the radio communication method of each of the searched base stations. Determine the communication device. When two or more wireless communication methods are available, the wireless communication device to be used for wireless communication is determined according to the above-mentioned priority.

【0056】

Next, the procedure of the communication device switching process executed by the communication control unit 112 will be described with reference to the flowchart of FIG.

【0057】

The communication control unit 112 first examines the current vehicle position and the above-mentioned base station information in order to investigate a wireless communication system having a wireless communication environment that covers the current vehicle position detected by the GPS unit 16 as a communication area. Based on the database, a base station having a communication area covering the current vehicle position is searched from the base station information database (step S101). In this step S101, all the base stations having a communication area covering the current position of the own vehicle and the wireless communication method of each of those base stations are detected.

【0058】

When a plurality of base stations having different wireless communication methods are searched, the communication control unit 112 selects a base station to be used for wireless communication according to the priority of each of the above-mentioned wireless communication methods (step S102).

【0059】

Next, the communication control unit 112 selects a wireless communication device to be used for wireless communication from the first to third wireless communication devices 26 to 28 according to the wireless communication method corresponding to the selected base station. (Step S103). The communication control unit 112 switches the wireless communication device to be used for wireless communication from a wireless communication device previously selected to the wireless communication device selected in step S103 (step S104).

【0060】

Then, the communication control unit 112 executes the communication process with the outside by using the wireless communication device selected in step S103 (step S105). In this case, the wireless communication device selected in step S103 establishes a wireless connection with the base station selected in step S102, and communicates with a server or the like on the Internet via the base station.

【0061】

In this way, the wireless communication device to be used for communication with the outside is automatically switched according to the movement of the vehicle position. This makes it possible to communicate with the outside using the wireless communication device that is most suitable for the current position of the vehicle. That is, it is possible to communicate with the outside from any place regardless of the destination of the automobile 100. The user does not need to be aware of the type of wireless communication device to be used for communication with the outside.

【0062】

While the automobile 100 is moving, the optimum base station and wireless communication method to be used are determined in consideration of not only the current position of the own vehicle but also the moving direction of the own vehicle. The moving direction of the own vehicle is detected by the gyro sensor 18.

【0063】

Next, an example of performing a communication device switching process when the communication environment of the wireless communication method currently used for communication with the outside deteriorates will be described with reference to the flowchart of FIG.

【0064】

Now, it is assumed that the first wireless communication device 26 is used to perform communication with the outside (step S111). The communication control unit 112 monitors the electric field strength level of the carrier signal from the base station corresponding to the first wireless communication method received by the first wireless communication device 26 (step S112). If the electric field strength level drops below a predetermined value (YES in step S112), the communication control unit 112 deteriorates the communication environment of the first wireless communication method corresponding to the first wireless communication device 26. It is determined that the operation has started, and the following communication device switching process is executed.

【0065】

That is, the communication control unit 112 searches the base station information database for the most suitable base station for communication from the current vehicle position (step S113). In this step S113, by considering the current vehicle position detected by the GPS unit 16 and the movement direction of the vehicle detected by the gyro sensor, the current position is covered as a communication area from each of the base stations. , Base stations that are expected to provide a good communication environment are searched. If a good communication environment is expected to be obtained, a plurality of base stations having different wireless communication methods (here, a base station corresponding to the second communication method and a base station corresponding to the third communication method). When is searched, the base station to be used for wireless communication (here, the base station corresponding to the second communication method) is selected according to the above-mentioned priority.

【0066】

Next, the communication control unit 112 selects a communication device corresponding to the wireless communication method of the selected base station, and selects the wireless communication device to be used for wireless communication from the first wireless communication device 26. Switch to a communication device, such as wireless communication device 27 (steps S114, S115). In step S115, the wireless communication device 27 establishes a wireless connection with the base station selected in step S113, and connects to a server on the Internet via the base station. This server is the same server with which the first wireless communication device 26 was communicating in step S111.

【0067】

Next, a third example of the procedure of the communication device switching process executed by the communication control unit 112 will be described with reference to the flowchart of FIG. 7.

【0068】

In this example, when the own vehicle position exists at a position where at least two of the first to third wireless communication methods can be used, the current priority of the in-vehicle electronic device 11 is not changed to the above-mentioned priority. The wireless communication device to be used for wireless communication is determined according to the moving speed of the vehicle, that is, the current traveling speed of the automobile 100.

【0069】

In the wireless communication device selection process according to the traveling speed, for example, the first wireless communication device 26 is preferentially selected while the vehicle is stopped, and the second wireless communication device 27 is preferentially selected during low-speed traveling. It is executed based on the policy of preferentially selecting the third wireless communication device 28 during high-speed driving.

【0070】

In general, the narrower the communication area covered by one base station, the greater the number of roaming that occurs with the movement of the mobile station. Roaming is a process (also referred to as handover) of switching a base station to be used for communication with a mobile station between base stations of the same wireless communication method.

【0071】

The communication area covered by each base station corresponding to the first wireless communication method (wireless LAN) is narrow. Therefore, when the first wireless communication method is used, depending on the moving speed of the mobile station, that is, the in-vehicle electronic device 11, the roaming process cannot be executed in time, which causes the in-vehicle electronic device 11 and the server to execute. The logical communication channel between them may be disconnected. From this point of view, in a system that selectively uses a plurality of wireless communication methods having different communication areas per base station, the wireless communication method that should be used according to the moving speed of the in-vehicle electronic device 11 is selected. The mechanism of selection is effective in executing stable wireless communication.

【0072】

It is assumed that the vehicle position exists in an area where only the third wireless communication method can be used, and the third wireless communication device 28 is selected. Communication with the outside is performed using the third wireless communication device 28 (step S121).

【0073】

It is assumed that the vehicle position moves to an area where all the first to third wireless communication methods can be used as the vehicle moves. In this case, the base station corresponding to each of the first to third wireless communication methods is searched from the base station information database as a base station that can be used for wireless communication.

【0074】

The communication control unit 112 detects the moving speed of the in-vehicle electronic device 11, that is, the traveling speed of the own vehicle by the signal from the vehicle speed sensor 17, and the own vehicle is stopped, is traveling at a low speed, or is traveling at a high speed. Is determined (step S122).

【0075】

If the own vehicle is stopped, the communication control unit 112 preferentially selects the first wireless communication device 26 corresponding to the first wireless communication method, and wireless communication to be used for wireless communication with the outside. The device is switched from the previously selected third wireless communication device 28 to the first wireless communication device 26 (steps S123, S126). Communication with the outside is performed using the first wireless communication device 26 (step S121).

【0076】

If the own vehicle is traveling at a low speed, the communication control unit 112 preferentially selects the second wireless communication device 27 corresponding to the second wireless communication method, and the radio to be used for wireless communication with the outside. The communication device is switched from the previously selected third wireless communication device 28 to the second wireless communication device 27 (steps S124, S126). Communication with the outside is performed using the second wireless communication device 27 (step S121).

【0077】

If the own vehicle is traveling at high speed, the communication control unit 112 preferentially selects the third wireless communication device 28 corresponding to the third wireless communication method (step S125). The wireless communication device to be used for wireless communication with the outside remains unchanged as the third wireless communication device 28. Communication with the outside is performed using the third wireless communication device 28 (step S121).

【0078】

As described above, the method of determining which wireless communication method to use according to the moving speed of the in-vehicle electronic device 11 can be applied to both the procedures of FIGS. 5 and 6.

【0079】

Next, a roaming process for switching base stations to be used between base stations corresponding to the same wireless communication method will be described with reference to the flowchart of FIG.

【0080】

In the present embodiment, in order to shorten the time required for roaming processing, high-speed predictive roaming is performed in which the base station of the roaming destination is predicted using the base station information database.

【0081】

In normal roaming processing, the mobile station receives a beacon signal from the base station, a response signal from the base station to a probe signal transmitted from the mobile station, and the like for a certain period of time in order to detect the existence of a base station around the mobile station. Continuous monitoring is required.

【0082】

In contrast, fast predictive roaming does not require monitoring of beacon or response signals. Therefore, by using high-speed predictive roaming, it is possible to significantly reduce the time required for roaming processing.

【0083】

The specific procedure for high-speed predictive roaming will be described below. Here, roaming between base stations corresponding to the first wireless communication method will be described as an example.

【0084】

Now, suppose that the current position of the automobile 100 is the point P3 in Fig. 2. The first wireless communication device 26 executes communication with the outside via the base station BS-A1 of FIG. 2 (step S131).

【0085】

The car 100 moves along the arrow in FIG. As the current position of the vehicle 100 approaches point P4 in FIG. 2, the electric field strength level of the carrier from the base station BS-A1 received by the first wireless communication device 26 begins to decrease. If the electric field strength level of the carrier from the base station BS-A1 drops below a predetermined value (YES in step S132), the communication control unit 112 sets the roaming destination based on the vehicle position. Search the base station information database for the base station to be used (step S133). For example, in FIG. 2, the base station BS-A2 is searched as a roaming destination base station.

【0086】

Actually, it is preferable to consider not only the position of the own vehicle but also the moving direction of the own vehicle. By considering both the vehicle position and the moving direction, it is possible to find the optimum base station at high speed even when there are a plurality of base station candidates to be roaming destinations. The direction of movement is detected by the gyro sensor 18. Further, when the own vehicle is traveling according to the route guidance, it is possible to detect the moving direction based on the route.

【0087】

Under the control of the communication control unit 112, the first wireless communication device 26 starts a process for wirelessly connecting to the base station BS-A2 in order to establish a session with the roaming destination base station BS-A2. (Step S134). Since the ID (address, etc.) of the base station BS-A2 can be obtained from the base station information database, the first wireless communication device 26 can actively start the connection with the base station BS-A2. .. The first wireless communication device 26 notifies the base station BS-A2 of the ID of the mobile base station BS-A1. As a result, the roaming process of switching the base station used by the first wireless communication device 26 from the base station BS-A1 to the base station BS-A2 is executed (step S135). After that, the first wireless communication device 26 executes communication with the outside via the base station BS-A2.

【0088】

The communication device switching function and the high-speed predictive roaming function in the present embodiment can be applied not only to in-vehicle electronic devices but also to portable information devices such as PDAs.

【0089】

Further, the wireless communication devices 26, 27, and 28 do not necessarily have to be realized by physically independent devices, and may be realized by one device in which the wireless communication method used by software can be switched.

【0090】

Further, the present invention is not limited to the above-described embodiment, and can be variously modified at the implementation stage without departing from the gist thereof. Further, the above-described embodiment includes inventions at various stages, and various inventions can be extracted by an appropriate combination of a plurality of disclosed constituent requirements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problems described in the column of problems to be solved by the invention can be solved, and the effects described in the column of effects of the invention can be solved. If is obtained, a configuration in which this configuration requirement is deleted can be extracted as an invention.

【0091】

[Effect of the invention]

As described in detail above, according to the present invention, it is possible to execute wireless communication with the outside regardless of the moving place.

[Simple explanation of drawings]

FIG. 1 is a block diagram showing a configuration of an in-vehicle electronic device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of the relationship between the movement path of the in-vehicle electronic device of the same embodiment and the communication area of each of the first to third wireless communication methods.

FIG. 3 is a diagram for explaining whether the communication device is switched as in the case where the in-vehicle electronic device of the same embodiment moves along the movement path of FIG.

FIG. 4 is a diagram showing an example of a base station information database used in the in-vehicle electronic device of the same embodiment.

FIG. 5 is a flowchart illustrating a first example of a procedure of a communication device switching process executed by an in-vehicle electronic device of the same embodiment.

FIG. 6 is a flowchart illustrating a second example of a procedure of communication device switching processing executed by the in-vehicle electronic device of the same embodiment.

FIG. 7 is a flowchart for explaining a process of selecting a communication device to be used by the in-vehicle electronic device of the same embodiment according to the moving speed of the in-vehicle electronic device.

FIG. 8 is a flowchart illustrating a procedure of high-speed predictive roaming processing executed by the in-vehicle electronic device of the same embodiment.

[Explanation of symbols]

11 ... Automotive electronic devices 12 ... System control unit 13 ... CD / DVD drive 14 ... Storage device 16 ... GPS unit 26 ... 1st wireless communication device 27 ... 1st 2 wireless communication device 28 ... 3rd wireless communication device 111 ... Navigation control unit 112 ... Communication control unit