JP3669979B2 - Mobile device, information communication system, and information communication method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mobile device, an information communication system, and an information communication method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, mobile devices that perform wireless communication by appropriately switching between a plurality of different wireless communication methods have been put into practical use with the development of wireless communication technology and the enhancement of functionality of mobile devices. Some of these mobile devices perform efficient data communication by constantly monitoring the radio field intensity when using each radio communication system and selectively using a radio communication system with stronger radio field intensity. Proposed. Examples of a plurality of different wireless communication systems include a wireless communication system that uses a third-generation mobile phone network such as FOMA (Freedom Of Mobile multimedia Access (registered trademark)) and a wireless LAN network.
[0003]
[Problems to be solved by the invention]
However, when the timing for switching the wireless communication method is determined based on the strength of the received radio wave as the only reference as in the above-described prior art, there are the following problems. That is, depending on the moving speed of the mobile device, the data path establishment process does not catch up with the transition of the communication area, and a time difference (time lag) occurs between the start of the switching process and the actual switching.
[0004]
Due to this time lag, there is a case where the wireless communication method is not switched at an appropriate timing. Specifically, before switching to the wireless communication method is completed, the mobile phone enters a different wireless communication method area and stops moving for a certain period of time or uses a high-speed wireless LAN, but moves slowly. There is concern about using the body communication network. Such a delay in switching timing is particularly noticeable when the moving speed of the mobile device is high.
[0005]
Therefore, an object of the present invention is for the mobile device to switch the wireless communication method at an appropriate timing.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a mobile device according to the present invention includes a storage unit that stores data of a region to which each wireless communication method is applied in a mobile device that performs wireless communication by switching between different wireless communication methods; Estimating means for estimating a moving state of a mobile device, switching means for switching a wireless communication system based on the data of the area stored in the storing means and the moving state estimated by the estimating means Prepare.
[0007]
In the information communication method according to the present invention, in an information communication method in which a mobile device performs wireless communication by switching between different wireless communication methods, an estimation step for estimating a moving state of the mobile device and each wireless communication method are applied. And a switching step of switching a wireless communication method based on the area data and the movement state estimated in the estimation step.
[0008]
According to these inventions, the wireless communication system and the data of the area to which the wireless communication system is applied are stored in the storage unit in association with each other. Then, the wireless communication system is appropriately switched based on the area to which each wireless communication system is applied and the estimated movement state of the mobile device. That is, the timing for switching the radio communication scheme is determined in consideration of the geographical relationship between each area to which the different radio communication scheme is applied and the current position of the mobile device. As a result, it is possible to sufficiently secure the processing time required for switching the wireless communication method before the mobile device reaches the destination area. As a result, the mobile device can switch the wireless communication method at an appropriate timing. These inventions are particularly effective when the moving speed of the mobile device is assumed to be large with a large switching timing delay.
[0009]
In the mobile device according to the present invention, preferably, the different wireless communication methods include a wireless communication method using a mobile communication network and a wireless communication method using a wireless LAN.
In the information communication method according to the present invention, preferably, the different wireless communication methods include a wireless communication method using a mobile communication network and a wireless communication method using a wireless LAN.
[0010]
Mobile communication via a base station is generally slower than a wireless LAN, but has a wide geographical range in which a mobile device can be used. On the other hand, the wireless LAN is capable of high-speed communication, although the geographical range in which the mobile device can be used is narrow compared with mobile communication. According to these inventions, for example, in a region where stable communication is possible even using a wireless LAN, the mobile device uses a higher-speed wireless LAN, and in other regions, the mobile device has a wide usable range. It is possible to select to use a body communication network. Further, since mobile communication and wireless LAN are switched at an appropriate timing according to the position where the mobile device exists, wireless communication utilizing the advantages of each method is possible.
[0011]
In the mobile device according to the present invention, more preferably, the measurement means for measuring the radio field intensity when using each wireless communication method, the detection means for detecting the position of the mobile device, and the measurement means measured by the measurement means And a determination unit configured to determine a wireless communication method applied to the mobile device based on a radio wave intensity and the position detected by the detection unit.
[0012]
In the information communication method according to the present invention, more preferably, the measurement is performed in the measurement step of measuring the radio field intensity when each wireless communication method is used, the detection step of detecting the position of the mobile device, and the measurement step. And a determination step of determining a wireless communication method applied to the mobile device based on the radio wave intensity and the position detected in the detection step.
[0013]
According to these inventions, first, the radio wave intensity when each wireless communication method is used is measured, and then the position of the mobile device is detected. Then, based on the measured radio wave intensity and the detected position, a wireless communication method applied to the mobile device is determined. It is estimated that the higher the measured radio field intensity is, the more wireless communication system that can perform stable communication for the mobile device. Therefore, by referring to the position where the mobile device exists and the radio wave intensity of each wireless communication method at that position, it is possible to clarify a region where it is preferable to apply each wireless communication method. Further, by storing the area and the applicable wireless communication method in association with each other in the storage unit, it is possible to refer to area data suitable for the mobile device.
[0014]
The mobile device according to the present invention may further include receiving means for receiving data of an area to which the wireless communication method is applied from an external terminal.
The information communication method according to the present invention may further include a reception step of receiving data of an area to which the wireless communication method is applied from an external terminal.
Furthermore, an information communication system including the mobile device described above and the external terminal may be constructed.
[0015]
According to these inventions, data in a region to which a wireless communication method is applied is received from an external terminal. The mobile device refers to the data in this area and determines the timing for switching the wireless communication method. For this reason, the mobile device does not need to generate the area data referred to when switching the wireless communication method. Therefore, the processing load on the mobile device is reduced. If the area data is acquired from an external terminal as needed, the data storage area of the mobile device can be saved. Furthermore, since a large number of data collected from other mobile devices is used, a more accurate area map can be generated.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
First, the configuration of an information communication system as an embodiment of the present invention will be described. FIG. 1 is a diagram showing an overall configuration of a communication system switching system 1 in the present embodiment. As shown in FIG. 1, the communication system switching system 1 includes a mobile device 10 (corresponding to a mobile device) and a map management server 20 (corresponding to an external terminal).
[0017]
The mobile device 10 can bidirectionally transmit and receive various data to and from the map management server 20 via the base station or access point and the communication network N. The base station A is a FOMA base station, and the access point B is a wireless LAN (Local Area Network) access point. The mobile device 10 is a dual network terminal that supports both FOMA and wireless LAN wireless communication systems, and can perform wireless communication between the base station A and the access point B using a communication unit described later. is there.
[0018]
The mobile device 10 functionally includes a FOMA radio wave measurement unit 11 (corresponding to measurement means), a wireless LAN radio wave measurement unit 12 (corresponding to measurement means), an area determination unit 13, and a position detection unit 14 (corresponding to detection means). , Area map generator 15 (corresponding to determining means), moving state estimating section 16 (corresponding to estimating means), wireless communication system switching section 17 (corresponding to switching means), FOMA communication section 18, wireless LAN communication section 19, area map storage Unit 110 (corresponding to storage means).
[0019]
Here, the area map storage unit 110 corresponds to a built-in memory such as an EEPROM (Electrically Erasable and Programmable Read Only Memory). Other constituent elements such as FOMA radio wave measurement unit 11, wireless LAN radio wave measurement unit 12, area determination unit 13, position detection unit 14, area map generation unit 15, movement state estimation unit 16, and wireless communication system switching The unit 17, the FOMA communication unit 18, and the wireless LAN communication unit 19 are realized by software stored in the built-in memory being executed by a CPU (Central Processing Unit).
[0020]
Hereinafter, each component of the mobile device 10 will be described in detail.
The FOMA radio wave measurement unit 11 constantly measures the strength of radio waves received from the FOMA base station A and outputs the measurement result to the area determination unit 13.
The wireless LAN radio wave measuring unit 12 constantly measures the strength of radio waves received from the access point B for the wireless LAN, and outputs the measurement result to the area determining unit 13.
Note that the measurement of the radio wave intensity is not limited to the mode in which the mobile device 10 measures itself, but data indicating the radio wave intensity may be acquired from notification information transmitted from the base station or the access point.
[0021]
The area determination unit 13 uses the radio wave intensity input from the FOMA radio wave measurement unit 11 and the radio wave intensity input from the wireless LAN radio wave measurement unit 12 to determine whether the mobile device 10 is currently in FOMA or wireless LAN. Determine if you are in the communication area. In the area determination based on the radio wave intensity, in view of the fact that the higher the radio wave intensity, the higher the reception level and the stable data transmission and reception are possible. judge.
[0022]
The position detection unit 14 measures the absolute position (latitude and longitude) of the mobile device 10 using GPS (Global Positioning System), which is a well-known and commonly used three-dimensional positioning technique. The position detection unit 14 outputs the measured latitude and longitude as position information to the area map generation unit 15 and the movement state estimation unit 16.
[0023]
The area map generation unit 15 refers to the area determination result by the area determination unit 13 and the position information acquired by the position detection unit 14 to determine a wireless communication method according to the position of the mobile device 10, and this wireless Generate an area map that reflects the communication method. The area map is data indicating a geographical area to which a radio communication scheme suitable for the mobile device 10 is applied, and is acquired by an area map acquisition process described later. The area map generation unit 15 can output the generated area map to the wireless communication system switching unit 17 and store it in the area map storage unit 110.
[0024]
The movement state estimation unit 16 estimates the movement state of the mobile device 10 from the temporal displacement of the position information acquired by the position detection unit 14. Here, the moving state is, for example, the moving direction, moving speed, speed change (acceleration), etc. of the mobile device 10. Specifically, the moving direction can be estimated from the latitude and longitude of the mobile device 10 at two time points. The movement speed can be estimated by calculating the movement distance from the latitude and longitude changes of the mobile device 10 and then dividing the calculation result by the unit time. The acceleration can be estimated by dividing the moving speed by the unit time.
[0025]
The wireless communication system switching unit 17 determines the timing for switching the wireless communication system based on the movement state of the mobile device 10 estimated by the movement state estimation unit 16 and the area map. The area map used for determining the switching timing may be input from the area map generation unit 15 or may be acquired from the area map storage unit 110 described later. In addition, the wireless communication system switching unit 17 switches the wireless communication system when the determined timing is reached.
[0026]
The FOMA communication unit 18 performs wireless communication with the FOMA base station A when the wireless communication method switching unit 17 switches the wireless communication method to FOMA. The FOMA communication unit 18 receives the area map transmitted from the map management server 20 via the communication network N and the base station A, and stores it in the area map storage unit 110.
[0027]
The wireless LAN communication unit 19 performs wireless communication with the access point B for wireless LAN when the wireless communication method switching unit 17 switches the wireless communication method to wireless LAN. Further, the wireless LAN communication unit 19 receives the area map transmitted from the map management server 20 via the communication network N and the access point B, and stores it in the area map storage unit 110.
[0028]
The area map storage unit 110 stores the area map received by the FOMA communication unit 18. The area map storage unit 110 stores the area map received by the wireless LAN communication unit 19. Of course, the area map storage unit 110 can also store an area map generated by the mobile device 10 itself. The area map storage unit 110 provides the stored area map to the wireless communication system switching unit 17.
[0029]
The map management server 20 collects and stores (accumulates) area maps generated by a plurality of mobile devices including the mobile device 10. The map management server 20 transmits the accumulated area map to the mobile device 10 via at least the communication network N and the base station A or the access point B. The transmitted area map is stored in the area map storage unit 110 of the mobile device 10.
[0030]
Next, the operation of the communication system switching system 1 will be described, and the information communication method according to the present invention will be described together. FIG. 2 is a flowchart showing an area map acquisition process executed by the communication system switching system 1.
[0031]
First, in S <b> 1 of FIG. 2, the FOMA radio wave measurement unit 11 acquires the FOMA radio wave intensity. In S <b> 2, the wireless LAN radio wave measurement unit 12 acquires the radio LAN radio wave intensity. Next, the area determination unit 13 compares the radio field intensity acquired in S1 with the radio field intensity acquired in S2 (S3), and determines the area where the mobile device 10 currently exists based on the comparison result. (S4).
[0032]
The area is determined as follows, for example. That is, when the radio field intensity of FOMA is higher than the radio field intensity of wireless LAN, mobile device 10 is regarded as being located in an area where FOMA is suitable for use as a wireless communication system. On the other hand, when the FOMA radio field intensity is less than or equal to the radio LAN radio field intensity, the mobile device 10 is regarded as being located in an area suitable for use of the wireless LAN as a radio communication method. Note that when comparing the radio field strength, a predetermined calculation may be performed such as adding a specified value to the radio field strength of one of the wireless communication systems.
[0033]
In S5, the position detection unit 14 acquires the latitude and longitude of the mobile device 10 at the present time as absolute position information. In S6, an area map is generated based on the area determination result in S4 and the position information acquired in S5. Various methods can be considered for generating the area map, and an example will be described below.
[0034]
FIG. 3 is a diagram conceptually showing an area map obtained as a result of executing the area map acquisition process described above. In FIG. 3, a solid line arrow Y <b> 1 and a broken line arrow Y <b> 2 indicate the trajectories that the mobile device 10 has moved. Further, a circle on the line indicates a change over time of the position of the mobile device 10 (measurement point of radio wave intensity) at a certain time interval t. In particular, white circles M11 to M111 and M21 to M28 indicate positions of the mobile device 10 in which the wireless communication method is determined to be FOMA, and other circles (black circles) indicate movements in which the wireless communication method is determined to be a wireless LAN. The position of the machine 10 is shown.
[0035]
For example, the mobile device 10 regards an area that falls within a circle having a predetermined radius (for example, about 5 m) centered on a position where the wireless communication method is determined to be a wireless LAN as an area to which the wireless LAN is applied. In addition, other areas are regarded as areas to which FOMA is applied. Although FIG. 3 shows an area map generated from two routes, it is possible to generate an area map with higher accuracy by using three or more routes.
[0036]
Next, FIG. 4 is a flowchart showing a communication method switching process that is executed and controlled by the communication method switching system 1. First, at T1, the movement state estimation unit 16 estimates the movement state of the mobile device 10 from the position information of the mobile device 10 acquired by the position detection unit 14. At T2, whether or not the mobile device 10 shifts the area in the travel destination based on the movement state estimated at T1 and the acquired area map by the wireless communication system switching unit 17 (whether or not there is area shift). Determined.
[0037]
The presence / absence of area transition is determined, for example, as follows. That is, the wireless communication system switching unit 17 monitors the moving direction of the mobile device 10 moving on the area map at regular time intervals t. As a result of monitoring, when areas of different wireless communication methods exist on the extension line in the moving direction and within a predetermined distance range (for example, about 10 m), the wireless communication method switching unit 17 causes the mobile device 10 to It is determined that the area is shifted to an area different from the communication system area.
[0038]
On the other hand, if it does not exist, the wireless communication system switching unit 17 determines that the mobile device 10 does not move to an area different from the area of the current wireless communication system. For example, the current wireless communication system area is a communication area to which the FOMA wireless communication system is applied, and the other area is a communication area to which the wireless LAN wireless communication system is applied.
[0039]
If it is determined at T2 that the mobile device 10 moves from one area to another (T2; Y), the wireless communication method switching unit 17 determines the communication method switching timing (T3). At T4, switching of the wireless communication system is started at the timing determined at T3. If it is determined at T2 that the mobile device 10 does not move the area (T2; N), the process returns to T1 and the movement state estimation process is performed again.
[0040]
Hereinafter, a specific processing example for determining the switching timing of the wireless communication method will be described with reference to FIG. As shown in FIG. 5, in the present embodiment, it is assumed that the mobile device 10 moves on the trajectory indicated by the broken line arrow Y3 and crosses the region R to which the wireless LAN is applied. Further, the distance that the mobile device 10 moves from time t4 until the mobile device 10 enters the region R is L1, and the distance that the mobile device 10 moves from time t7 until the mobile device 10 leaves the region R is L2. And
[0041]
In this case, assuming that the moving speeds of the mobile devices 10 at times t1 to t7 are V1 to V7, respectively, the timing T1 for switching the wireless communication system from FOMA to wireless LAN is the estimated required time L1 / V4 until reaching the region R, It is determined when the time tp required for establishing a wireless LAN path is less than the time tp (that is, L1 / V4 <tp). On the contrary, the timing T2 at which the wireless communication system is switched from the wireless LAN to the FOMA is the time when the estimated required time L2 / V7 for leaving the region R is less than the time tr required for establishing the FOMA path (that is, L2 / V7). <Tr).
[0042]
That is, the mobile device 10 starts processing for establishing a wireless LAN path at timing T1, and starts processing for establishing a FOMA path at timing T2. As a result, a sufficient and less wasteful migration processing time is ensured in order to establish the path of the switching destination wireless communication system. Therefore, the mobile device 10 does not enter an area of a different wireless communication method before the switching of the wireless communication method is completed. This eliminates the concern that data communication is stopped for a certain period of time from entering the area to starting communication, or that FOMA is used even though a higher-speed wireless LAN can be used. That is, the mobile device 10 can perform efficient data communication while smoothly transitioning between areas.
[0043]
Note that the present invention is not limited to the above-described embodiments, and modifications can be appropriately made without departing from the spirit of the present invention. For example, in the present embodiment, as a different wireless communication method, a wireless communication method using a mobile phone network and a wireless LAN network is exemplified. However, as long as the wireless communication systems are different from each other, wireless communication systems using a mobile phone network such as FOMA and PDC (Personal Digital Cellular) may be used. In addition, the subject that switches the wireless communication method is not limited to the mobile device, but may be a communication card.
[0044]
Finally, a program for realizing the wireless communication system switching technology according to the present invention will be described. The program can be executed by the mobile device 10 that performs wireless communication by switching between different wireless communication methods. The program includes an estimation module, a switching module, a measurement module, a detection module, a determination module, and a reception module.
[0045]
The estimation module has a function of causing the mobile device 10 to estimate the moving state of the mobile device 10. The switching module has a function of causing the mobile device 10 to switch the wireless communication method based on the data of the area to which each wireless communication method is applied and the estimated movement state.
[0046]
The measurement module has a function of causing the mobile device 10 to measure the radio field intensity when each wireless communication method is used. The detection module has a function of causing the mobile device 10 to detect the position of the mobile device 10. The determination module has a function of causing the mobile device 10 to determine a wireless communication method applied to the mobile device 10 based on the measured radio wave intensity and the detected position.
[0047]
The reception module has a function of causing the mobile device 10 to receive data in an area to which the wireless communication method is applied, transmitted from the map management server 20.
Furthermore, the above-described wireless communication system switching technology may be provided as a recording medium on which the program is recorded and can be read by the mobile device 10.
[0048]
【The invention's effect】
According to the present invention, the mobile device can switch the wireless communication method at an appropriate timing.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a functional configuration of a communication system switching system.
FIG. 2 is a flowchart for explaining area map acquisition processing;
FIG. 3 is a diagram illustrating an example of an area map.
FIG. 4 is a flowchart for explaining communication mode switching processing;
FIG. 5 is a diagram conceptually illustrating a relationship between an area to which a wireless LAN is applied and a timing at which switching of a wireless communication method is started.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Communication system switching system, 10 ... Mobile station, 11 ... FOMA radio wave measurement part, 12 ... Wireless LAN radio wave measurement part, 13 ... Area determination part, 14 ... Position detection part, 15 ... Area map generation part, 16 ... Movement state estimation , 17 ... Wireless communication system switching unit, 18 ... FOMA communication unit, 19 ... Wireless LAN communication unit, 110 ... Area map storage unit, 20 ... Map management server

Claims (2)

In mobile devices that perform wireless communication by switching between different wireless communication methods,
Storage means for storing data of a region to which each wireless communication method is applied;
Estimating means for estimating a moving state of the mobile device;
Based on the data of the area stored in the storage means and the movement state estimated by the estimation means, whether or not there is a transition to an area where a wireless communication method not used by the mobile device is applied Determining means for determining
A calculating means for calculating a switching timing to the wireless communication method when the determining means determines that the mobile device is to be transferred;
Establishing means for starting a process for establishing a path for the wireless communication method at the switching timing calculated by the calculating means;
Switching means for switching the wireless communication system used by the mobile device to a wireless communication system in which a path is established by the establishment means;
An area data collection unit that acquires area data generated by another mobile device from an external area data management server and stores the area data in the storage unit as the area data. Machine. Measuring means for measuring the radio field intensity when using each wireless communication method,
Detecting means for detecting the position of the mobile device at the time of measuring the radio field intensity;
A determination unit for storing data in a region that can be referred to when switching a wireless communication method based on the radio field intensity measured by the measurement unit and the position detected by the detection unit;
The mobile device according to claim 1, further comprising: area data transmitting means for transmitting the area data stored in the storage means by the determining means to an external area data management server. .

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