Communication system

A communication system is provided of selecting the most approximate line from two or more connectable lines and connecting with a provider through the selected line in the mobile communication environment. The mobile device and the public phone of each phone company provide a standard wireless data communication facility, respectively. The public line pre-stores information about dial-up numbers of access points and a transmission speed of an internet provider. When the user starts the communication, the mobile device operates to obtain the most approximate access point information from each of the public phones and then dial up the most approximate access point through the public phone/line well-specified to the user.

BACKGROUND OF THE INVENTION

The present invention relates to an improved communication system arranged to connect with the internet in the mobile environment. In particular, the present invention relates to the communication system which is arranged to communicate data between a mobile device and an access point of an internet provider through a wireless communication path between the mobile device and an instrument such as a public phone served as a contact point with the public line.

As the wireless communication technology, it is considered to use the Bluetooth (which is the inexpensive standards of the short-distance radio communication interface between the data and the voice through the use of the 2.4 GHz band) or a wireless LAN (which is the LAN standards of a short-distance wireless communication on the 2.4 GHz band).

Conventionally, in the case of executing the data communication in the mobile environment such as the outdoor like the office, in general, at first, a portable wireless phone such as a PHS (Personal Handyphone System) or a PDC (Personal Digital Cellular) is connected to the mobile device such as a notesized personal computer or a PDA (personal digital assistant). Then, the mobile device is served to dial an access point of the provider for accessing the internet or transferring electronic mails.

As the data communication method arranged to use a public phone, a public phone provided with an ISDN (Integrated Service Digital Communication Network) interface for data communication may be used for wired connection. In addition, another type of public phone provided with an IrDA (Infrared Data Association) port may be presented outdoor.

If not in the mobile environment, today, the LCR (Least Cost Routing) function may be used for the wired communication through the use of a wired phone line or the like. The LCR function is served to periodically transfer toll information of each phone company's line to a fixed phone with the LCR contract made and then to select the least inexpensive communication line based on the information. This LCR function is made available to the fixed (stationary) phone but not available to the mobile environment like the outdoor. That is, in the case of using the portable wireless phone such as the PHS or the PDC, for example, the LCR function is set so that no communication may be executed between the different wireless data communication carriers as in the case that the user uses the PDC made by the A company to access the base station of the B company. Nowadays, no choice is allowed from a plurality of carriers. This holds true to the IMT-2000 (International Mobile Telecommunications 2000).

As the prior art about the communication system in which a plurality of different communication paths are made available, there have been known the technologies in JP-A-9-172430 or JP-A-10-304071. In these prior arts, a plurality of wired communication circuits and a plurality of wireless communication circuits are provided in the communication system apparatus, which holds relevant data such as a transmission speed and a toll of each line so that the line may be automatically selected in accordance with the selected specifications inputted by the user.

Further, as another prior art, there have been known the technology in JP-A-2000-32047. This technology concerns with the mobile device (portable device) using the PHS as the communication means. The location information of each PHS is held in the PHS management center. The PHS management center operates to identify an area code of a public phone from the location information and to transfer this area code to the PHS. Then, the mobile device operates to automatically dial an access point of the provider with the most approximate specification on the basis of the content of the phone number list of all the access points of the connectable providers owned by the mobile device itself and the area code transferred from the management center.

The data communication through the use of the PHS or the PDC in the mobile environment of the foregoing prior art may use only the carrier of the PHS or the PDC used on the user's contract. At the contract time point of the PHS or the PDC, it is necessary to determine one carrier (of the communication company) to be used. The foregoing prior art allows a plurality of PHS or PDC carriers (communication companies) to be contracted. In this case, as the basic fee, the sum of the basic fees of the contracted carriers is required. The total cost is increased accordingly.

Afterwards, the deregulation of the communication results in increasing the number of new companies to be joined into the communication business, which may lead to the abrupt competition of tolls among the phone companies. Further, it is considered that the reduction or revision of the toll is frequently carried out. However, the foregoing prior art is required to determine the carrier (phone company) in the specification given when the PHS or the PDC is contracted. This makes it impossible to select a line at any place or time.

The foregoing LCR function is served to periodically transfer toll information of each company line to a fixed phone and select the least costly communication line based on the information. It cannot be used in the mobile environment like the outdoor as it is.

The prior arts disclosed in JP-A-9-172430 and JP-A-10-304071 are specified to have a plurality of wireless or wired communication devices. Hence, the user has to carry a plurality of wireless data communication devices. As mentioned above, the cost like the basic fees are increased. So are the overall weight of the devices carried by the user and the electronic power of the devices.

The prior art arranged to use the PHS disclosed in JP-A-2000-32047 is arranged to dial the nearest access point of the provider. As mentioned above, however, no choice of a low-toll line is allowed.

Moreover, the prior art arranged to use the public phone provided with the ISDN interface for data communication requires the user to connect the mobile device or the public phone through a cable at his or her own will and the user to search a proper access point of the provider and then dial it. The public phone provided with the IrDA port requires the user to move the mobile device in front of the public phone, make the IrDA port of the mobile device closer to the IrDA port of the public phone, and search the access point of the provider for dialing it. The both types of public phones burdens the user with a troublesome work.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a communication system which is arranged to retrieve a line-connecting carrier without the user's consciousness of it and automatically select the most approximate line or select the most approximate access point to the provider through the use of the wireless data communication in the mobile environment.

In carrying out the object in a preferred mode, the communication system arranged so that a portable computer having a communication function may use a public phone characterized in that the computer and the public phone provide a standard wireless data communication device, respectively, the computer obtains information of lines and information of contacts of internet providers from the public phone, the computer selects the most approximate line and contact point based on the information, the wireless data communication is executed between the computer and the public phone on the selected line and contact point, the public phone is connected with the connecting line of the internet provider, and the computer is connected with the internet.

The foregoing standard wireless data communication device may be the Bluetooth or the wireless LAN. The public phone carries out a protocol conversion between the standard wireless data communication and the phone line and then is connected with the access point of the provider through the phone line. The provider operates to transfer the access point information to the center station of the phone company through the phone line. Then, the center station of the phone company operates to select the effective access point information to each public phone and then transmit the access point information to each public phone. In a case that a portable computer served as the mobile station is located in the wireless data communication range of the public phone and the user tries to make access to the provider, the computer enables to automatically retrieve the communicable public phone, obtain the phone line information and the access point information from all the communicable public phones, select the most approximate public phone and access point, and connect to the selected ones.

According to the invention, the communication system is arranged to retrieve the line connecting carriers without the user's consciousness of it, and automatically select the most approximate line from the carriers or select the most approximate access point to the provider.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereafter, the description will be oriented to a communication system according to an embodiment of the present invention.

FIG. 1Ais a block diagram showing an overall arrangement of a communication system according to an embodiment of the present invention. InFIG. 1A, a numeral1denotes the internet. A numeral2denotes a provider of an A company. A numeral3denotes a provider of a B company. A numeral4denotes a provider of a C company. Numerals5to7denote databases (DBs) of a provider. A numeral8denotes a mobile device. Numerals9and32to34denote standard wireless data communication facilities. Numerals11to19denote a line access point (AP) of the provider. Numerals20to22denote line networks of the phone companies. Numerals23to25denote DBs of the center stations of the phone companies. Numerals26to28denote public phones of the phone companies. Numerals29to31denote DBs of the public phones of the phone companies. Numerals35to37denote standard wireless data communication ranges of the public phones of the phone companies.

FIG. 1Bshows an internal arrangement of the mobile device8. The mobile device8includes a memory802for storing data or programs, a CPU801for executing programs and processing data, a monitor806for visually outputting the processed result of the CPU, a keyboard805by which an operation gives an indication or enters data, a controller804for transferring data or controlling the memory between the components, and a communication controller803corresponding to the foregoing wireless facility9.

Though not shown, the public phone of each phone company, the host computer of the phone company for managing the DBs23to25, and the server to be used by the provider for managing the AP information provide the same elements as shown inFIG. 1B, respectively. The operation of the software for executing the processing flow to be described in this embodiment makes it possible to fulfill their functions.

The communication system shown inFIGS. 1A and 1Bincludes a mobile device8like a portable computer having the standard wireless data communication facility9like the Bluetooth, a standard wireless data communication facility32, the public phone of the X phone company having the DB29, a standard wireless data communication facility33, the public phone27of the Y phone company having the DB30, a standard wireless data communication facility34, and the public phone28of the Z phone company having the DB31. The X phone company26is connected with the line network20of the X company. The public phone27of the Y company is connected with the line network21of the Y company. The public phone28of the Z company is connected with the line network22of the Z company. The center station of the public phone26of the X company includes the DB23. The center station of the public phone27of the Y company includes the DB24. The center station of the public phone of the Z company includes the DB25. The A company provider2having the DB5and the APs11to13, the B company provider3having the DB6and the APs14to16, and the C company provider4having the DB7and the APs17to19are connected to the internet1, in which the APs11to19are connected with the line networks20to22of those companies.

The company providers2to4include the information about the AP in the DBs5to7, respectively. As shown inFIGS. 3 to 5, the DB of the AP information owned by the provider of the A, B and C companies includes a provider number and a provider name for identifying the provider itself, an ID number of the AP, a name of the AP, a phone number of the AP, a line type of the AP, a transmission speed of the AP, and option information such as line congestion information, contract information, and associated provider information. The provider number is used for identifying each company. Hence, it is preferable that the provider number is managed by a third authority so as not to be overlapped with another number. The AP number is managed by the provider of each company. The line congestion information means the congestion of the AP measured by each provider. For example, as shown inFIG. 6, the line congestion information should be gathered on each hour and day of the week. This AP information is periodically rewritten into the latest information by each provider.

As an example of the contract information, the example of the content of a service plan contracted by the provider and the user is shown inFIG. 7. In this example, the contract information includes a plan number and name for identifying a service plan, a basic fee for indicating a toll, a usable time of the basic fee, an additional fee of the surplus time, and the option information including an associated phone line and a line discount.

The information of the associated provider included in the AP information corresponds to the information of the associated provider. For example, the A net shown inFIG. 3is tied up with the providers of the provider numbers57and125.

Each provider operates to periodically send the AP information as shown inFIGS. 3 to 5to the center station of each phone company through the lines20to22of the phone company. The AP information is held in the DBs23to25included in the center station of the phone company.

The center station of the phone company operates to transmit to the public phone the AP information having been sent from the provider. In a case that the center station transmits the AP information to the public phone, the center station may transmit all the information held thereby or selectively transmit the necessary information to the public phone.

With reference to the flow shown inFIG. 2, the description will be oriented to the processing operation of how the center station of the phone company selects the necessary information to the public phone and transmits the selected information.

(1) The operation is executed to check if the time reaches the proper time when the information is to be transmitted. If not, the transmission is awaited until the proper time comes (steps101and102). The center station of the phone company periodically transmits the information. However, too much frequent transmission of the information increases the traffics on the line, which brings about the large line congestion. Hence, this transmission should be executed at a frequency of once a week, for example.

(2) If the proper time when the information is to be transmitted comes at the step102, the center station operates to read the list of the nationwide area codes held thereby, selects the area code in sequence from the first top area code of the list, and prepare transmission of the information with the area code as x (steps103and104).

(3) The center station of each phone company operates to selectively extract the AP information corresponding to the area code assumed as x at the step104as the information to be sent to the public phone from the AP information of the provider of each company held in the DB23to DB25prepared in each station. For example, if x=044, the center station operates to select the AP information having ‘044’ as the area code (step105).

(4) The center station of the phone company operates to transmit the AP information selectively extracted at the step105to the public phone of the subject phone company having the area code x (step107).

(5) Afterwards, the center station of the phone company operates to check if the area code x is the last one of the nationwide area code list. If no, the center station operates to repeat the process from the step105assuming that the next one of the area code list is x (steps108and106).

(6) If the area code x is determined to be the last one of the nationwide area code list in the check of the step108, it means that the transmission of all the AP information to the public phone is terminated. Hence, the process is terminated (step109).

In the foregoing process, if the center station of the phone company X selects the AP information from the AP information of the provider of each company shown inFIGS. 3 to 5with the area code as x=044, the AP information is selected as shown inFIG. 8, and then the AP information is transmitted to the public phone of the area code044.

In the foregoing description of the process, the center station operates to select the AP information having the area code x and then transmit the public phone of the area code x. In place, the center station may select the AP information having the area codes (x−1) to (x+1) and then transmit the information to the public phone of the area code x. Further, since the area codes of the adjacent areas may not be necessarily ranged in sequence, the specific area codes may be combined with each other before transmitting the information.

The public phone, which is inputted with the AP information of each provider selected as mentioned above, the AP information being transmitted from the center station of the phone company, operates to add the toll information to the AP information as shown inFIG. 8. The toll information is transmitted to the public phone together with the AP information or separately from the center station of the phone company. For example, it is assumed that the public phone26of the X phone company shown inFIG. 1has an area code of 044, the center station of the X phone company transmits the AP information of the provider as shown inFIG. 8to the public phone26, and then the AP information is stored in the DB29.

In this assumption, the public phone26of the X phone company includes in the DB29the toll taken when the public phone of the subject company accesses the phone number of each AP information as shown inFIG. 8as the toll list of the subject phone company as shown inFIG. 9. The public phone26operates to extract from this toll list the toll taken in accessing the phone number of each AP information shown inFIG. 8and then add this toll information to the information shown inFIG. 8. As this result, the public phone26operates to hold in the DB29the information as shown inFIG. 10as the line information to which this toll information is added.

Like the foregoing description, the public phone27of the Y phone company, which is inputted with the AP information transmitted from the center station of the Y phone company, includes the addition of the AP information into the toll information. Moreover, the public phone28of the Z phone company, which is inputted with the AP information transmitted from the center station of the Z phone company, includes the addition of the AP information to the toll information. In this state, the public phone of each phone company includes the AP information, the transmission speed, the type, the line congestion, the contract information, the associated (tie-up) provider information, and the toll information of the same area of each company's provider as shown inFIG. 10.

The public phones26to28provide the standard wireless data communication facilities32to34, respectively. The public phones26to28may communicate with the mobile device8having the standard wireless data communication facility9in the standard wireless data communication ranges35to37through the use of the standard wireless data communication facilities32to34, respectively.

FIG. 11is a diagram showing a connection/network hierarchy from the internet to the mobile device, partially extracted from the overall arrangement of the communication system shown inFIG. 1.FIG. 11shows the communication protocol in the case that the Bluetooth are used as the standard wireless data communication facilities32to34. Hereafter, this arrangement will be described below.FIG. 11is a block diagram showing each device and the communication method in the upper portion ofFIG. 11and the communication protocol corresponding thereto in the lower portion ofFIG. 11.

InFIG. 11, a numeral50denotes a mobile device. Numerals51and53denote the Bluetooth modules. A numeral52denotes a wireless data communication path. A numeral54denotes a public phone. A numeral55denotes a phone line. A numeral56denotes a dial-up router. A numeral57denotes the internet. A numeral58denotes a PCMCIA interface. A numeral59denotes a USB interface. A numeral60denotes a network hierarchy of the mobile device. A numeral61denotes a network layer IP of the mobile device. A numeral62denotes a data link layer PPP of the mobile device. A numeral63denotes a physical layer PCMCIA of the mobile device. A numeral64denotes a network hierarchy of the Bluetooth module. A numeral65denotes a physical layer PCMCIA of the Bluetooth module. Numerals66and68denote physical layers (wireless) of the Bluetooth module. A numeral67denotes a network hierarchy of the Bluetooth module. A numeral69denotes a physical layer USB of the Bluetooth module. A numeral70denotes a network hierarchy of the public phone. A numeral71denotes a physical layer USB of the public phone. A numeral72denotes a physical layer V.n of the public phone. A numeral73denotes a network hierarchy of the dial-up router. A numeral74denotes a data link layer PPP of the dial-up router. A numeral75denotes a physical layer V.n of the dial-up router. A numeral76denotes a network layer IP of the dial-up router. A numeral77denotes a data link layer/physical layer LAN of the dial-up router.

The mobile device50shown inFIG. 11is connected with the Bluetooth communication module51through the interface58of the PCMCIA (Personal Computer Memory Card International Association) standards. The communication protocol60of the mobile device50uses an IP (Internet Protocol) for the network layer61, a PPP (Point-to-Point Protocol) for the data link layer62, and a PCMCIA for a physical layer63. This kind of protocol is just exemplary. In place, the communication protocol60may use Mobile IP or Ipv6 (IP Version 6) for the network layer61, and a USB (Universal Serial Bus) for the physical layer63. The data from the mobile device50is converted into the wireless data communication signal in the Bluetooth module51and then is converted into the USB signal in the Bluetooth module53on the side of the public phone54.

In the embodiment shown inFIG. 11, the public phone54and the Bluetooth module are connected through the USB interface59. In place, the PCMCIA or another interface may be used. In actual, it is practical that the Bluetooth module is built in the public phone54. The public phone54includes a circuit for converting the signal of the USB into a phone line signal.

In the embodiment shown inFIG. 11, the public phone54includes a modem function of the analog line and the phone line55is an analog line. The line may be the ISDN, the ADSL, the CATV or the like in place of the analog line. The V.n72 shown inFIG. 11is the analog modem standards. It may be V.90 (56 kbps). The public phone54is connected to the dial-up server56of the provider through the public line55. The dial-up server56performs a password authentication protocol through the PPP protocol of the data link layer74for the purpose of authenticating the user of the password. Then, the dial-up server56is LAN-connected with the internet57. The method of authenticating the user is the same as the commonly available method used in the existing dial-up connection.

In turn, the description will be oriented to the processing operation of how the AP information (shown inFIG. 10) of the provider is transferred between the mobile device8shown inFIG. 1and the public phones26to28with reference to the flow shown inFIG. 12. The mobile device8and the public phones26to28include the communication programs for executing this process, respectively. This program may be executed intentionally or be automatically and periodically executed between the mobile device8and the public phones26to28when the mobile device8enters into the wireless data communication ranges35to37like the wave receipt level of the portable phone even if the user is aware of it.

(1) When the program is started, the mobile device8operates to search the public phone that may provides a capability of wirelessly communication data. In the embodiment shown inFIG. 1, the mobile device8enables to communicate the public phone26of the X phone company with the public phone27of the Y company and check if the communicable public phone is found. If not found, the program is terminated. (steps110to112).

(2) If a communicable public phone is found in the check of the step112, the mobile device8operates to transmit the information of the provider contracted by the user carrying the mobile device itself to the public phone and requests the public phone to transmit the AP information of the provider. The information of this provider may be the name of the provider or the number thereof. For example, inFIG. 1, if the user of the mobile device8contracts with the provider of the B company, as shown inFIG. 14, the B net or No.73is notified to the public phone (step113).

(3) As a result, the public phones26to27to be communicated with the mobile device8operate to extract only the information of the provider of the B company from the provider information (seeFIG. 10) carried in the public phones and then give back the extracted information to the mobile device8. The mobile device8receives the AP information transmitted from the public phones26and27(step114).

(4) It is checked if another communicable public phone still exists. Then, if two or more idle public phones are found, the mobile device8operates to transfer the provider information of the B company with another public phone in sequence. In the embodiment shown inFIG. 1, since the mobile device8stays in the communicable range with the public phones of the X phone company and the Y phone company, the mobile device enables to obtain the information as shown inFIG. 14(step115).

The user of the mobile device8selects one AP from the obtained provider information and communicate data at the AP. At this time, the line of the public phone, that is, the type of the line55shown inFIG. 11limits the AP of the provider. In the embodiment shown inFIG. 14, the public phone line of the X phone company is the ISDN 64 kbps and the public phone line of the Y phone company is the ISDN 128 kbps. The AP is required to comply with this type of line. In this case, only the data shown in the half-tone dot meshing portion may be selected as effective information. Hence, if the public phone sends the AP information to the mobile device, it is possible to send only the effective information shown in the half-tone dot meshing portion shown inFIG. 14.

If no AP of the provider contracted by the user is found, the public phone enables to transmit the information of the associated provider from the associated provider information. For example, if the user make a contract with the provider of the C phone company, as shown inFIG. 5, the public phone is the provider No.725of the C phone company and operates to transmit to the mobile device the A net information of the provider No.16shown inFIG. 10including the item No.725of the associated provider in the information shown inFIG. 10carried in the public phone. In addition, even if an AP of the provider contracted by the user is found, by referring to the associated provider information, it is possible to transmit the AP information of the associated provider.

In the foregoing process, the process of how the mobile device searches the public phone to wirelessly communicate data is executed by the detection of the radio signal issued by the public phone in the mobile device. The service information to be notified to lots of unspecific users is put on the radio signal issued by this public phone. This makes it possible for the user to view various kinds of information from the phone company at this point.

In turn, the description will be oriented to the processing operation of how the mobile device8selects a proper public phone from the foregoing information and is connected to the AP with reference to the flow ofFIG. 13. The program for executing this process is started when the program of obtaining the line information described with reference toFIG. 12is completed. If a communicable public phone is found, the line selection and the connection are executed. The user has to determine the connecting mode on the program of the mobile device in advance. This mode may be an automatic line connecting mode or a manual line connecting mode. In a case that the mode is set to the automatic line connecting mode, if any communicable line exists and the specification set by the user in advance is met, the connection is automatically executed. The setting specifications are an allowance of the toll, an allowance of the line congestion, a transmission speed, a time, and so forth. If the mode is set to the manual line connecting mode, the user makes sure of the specification of the public phone before performing the connection.

(1) When this processing program is started, the mobile device8operates to check if a communicable public phone is found. If no, the process is terminated. If yes, it is checked if the connecting mode is set to the automatic line connecting mode (steps120to122).

(2) If the mode is set to the automatic line connecting mode at the step122, the mobile device8operates to compare the information (see the half-tone dot meshing ofFIG. 14) of one connectable line with the information of another, select the well-specified line, and dial up to the AP with the selected public phone.

In the case of this automatic line connecting mode, when the connection is started, as shown inFIG. 16, the checking screen may be displayed (steps127and128).

The line type, the transmission speed, the toll, the provider, and the line congestion on the checking screen shown inFIG. 16are used as the setting screen on which the user may input the data into the mobile terminal. The specification required by the user may be inputted to the mobile terminal from this screen. In this case, as a possible operation, if a communicable public phone is found, the specification requested by the user, inputted on the setting screen, is transmitted to the public phone. Then, the public phone searches the AP that meets this specification and automatically dials up to the AP, and then starts the line connection. When the public phone obtains the provider information and the user-requested specification from the mobile device (for example, the provider name73(B net), the line ISDN, the speed 64 kbps, the line congestion 10% or less, the toll 9 yen a minute or less), the public phone operates to select the provider that meets this specification from the DB (seeFIG. 10) carried by itself and automatically dials up to the provider. In a case that the connecting mode is set to the automatic line connecting mode at which the connection is automatically determined, since no AP information is found inside the mobile device, the operation shown inFIG. 12is not required. If two or more communicable public phones are found, it is necessary to request one public phone to do connection without having to transmit the request for connection to two or more public phones at a time. Moreover, the specification shown inFIG. 16may be pre-stored in the mobile device without having to input it each time. This specification may be read on this setting screen. In this state, the user may start to perform the connection if the specification is met (transformation of the steps127and128).

If the mode is not set to the automatic line connecting mode at the step122, if the line connection is manually executed, the specification of the public phone as shown inFIG. 15is displayed on the mobile device. The user makes sure of this specification. Then, if the user would like to perform the connection, the connection to the AP is started through the public phone selected by the user (steps123to126).

Ordinarily, in the case of dialing up to the internet through the provider, the user makes a contract with the provider and the contracted provider charges the toll for the user. Also in the embodiment of the present invention, the similar method is used for payment of the toll. The toll is calculated from a product of the toll and the time of use and the fee is paid by the provider to the phone company. Then, the total amount of the internet connecting fee to be ordinarily paid by the user to the provider and the toll corresponds to the amount billed by the provider to the user. This method does not require the user to make contracts with two or more phone companies. It requires the user to merely make a contract with the provider.

In the foregoing embodiment of the invention, the ID number of the business owner is not assigned to the phone number of the public phone. The public phone merely includes a number like 044-XXX-XXXX. However, if necessary, the ID number of the business owner may be added to the top of the area code. The present invention may be applied to this case.

In the foregoing embodiment of the invention, the connection of the mobile device to the public phone may hold true to the connection of the mobile device to the public phone provided with the ISDN interface or the IrDA interface of the prior art. However, the prior art in which the connection is executed through the ISDN or the IrDA requires the user to move to the public phone to be connected to the mobile device and intentionally select the public phone. Further, the user has to search the phone location and the connecting AP number. If the wireless interface is in use, unfavorably, the user disables to search the connectable public phone.

The foregoing embodiment of the present invention is arranged to use the wireless device such as the Bluetooth or the wireless LAN. This embodiment has a shorter wave propagation distance than the existing PHS or PDC. In particular, it is practical enough to use this embodiment in a crowded public place like an airport lobby and a hospital waiting room when accessing the internet, downloading various kinds of data, and transferring an electronic mail through the use of the wireless data communication technology.

Moreover, the needs of downloading multimedia data or application software such as music or motion pictures will be easily on the rise in near future. In order to correspond with these needs, it is necessary to improve the transmission speed. In the foregoing embodiment of the present invention, since the Bluetooth or the wireless LAN is relatively fast even in the current state, what is required is only to make the wired portion of the public phone line of a fast optical fiber cable. This is technically easier than the increase of the speed in the wireless system such as the PHS, the PDC or the IMT-2000. Moreover, today, the optical fiber cable comes to a telephone pole near the house. The use of the optical fiber thus makes it possible to implement the embodiment far more inexpensively than the installation of the base station of the IMT-2000.

According to the foregoing embodiment of the invention, it is possible to use the wireless data communication in the mobile environment, search the line connecting carrier without the user's consciousness of it, and automatically select the line with the most approximate specification. Further, the most approximate AP of the provider may be automatically selected.

It is presumed in future that the Bluetooth and the wireless LAN is mounted onto the mobile device and the Ipv6 (IP Version 6) to be switched worldwide may provide various kinds of electric products with their own IP addresses in connecting them to the network. It is practicable to mount the Bluetooth onto the public phone with the IP address. The embodiment of the present invention makes it possible for the mobile PC to automatically select the connecting target. Moreover, the embodiment also makes it possible to search the well-specified inexpensive line in the mobile environment like the outdoor and to simply connect to the internet or accept various kinds of services from the provider.