JPH11313371A - Mobile data communication system, its base station device amd mobile terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute efficiently a selection request of a radio data communication protocol by selecting an available radio data communication protocol among plural radio data communication protocols based on an idle capacity of each radio channel and informs a mobile terminal being a request source of it. SOLUTION: When a mobile terminal PS1 makes dialing to designate a radio communication data communication protocol, the mobile radio terminal PS1 sends a call connection request used to request a radio data communication protocol to a base station CS1. Upon the receipt of the call connection request from the mobile terminal PS1, the base station CS1 discriminates a connection type and selects a protocol in the case of data communication, detects number of idle radio communication channels and discriminates whether or not a request channel is available. A gateway GW receives a call connection request to open an SVC via a leased line network PN.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to, for example, PHS
(Personal Handy-phone System), a mobile data communication system enabling mobile data communication between the mobile terminal device and a data communication device connected to a wired communication network, and a base station device and a mobile terminal Related to the device.

[0002]

2. Description of the Related Art In recent years, digital mobile communication systems typified by cellular telephone systems and PHS have rapidly become widespread. In this type of system, in addition to a voice communication service, provision of a data communication service using a personal computer connected to a mobile phone or a portable information terminal having a wireless communication function has been started.

For example, when a user attempts to obtain desired information or the like from a server device on a computer network such as the Internet, a call is made from the portable information terminal to the desired server device. Then, first, the portable information terminal and the nearest base station are connected via a wireless link, and subsequently the base station accesses a data communication device such as a gateway via a wired communication network such as a public network. When a connection for data communication is established between the base station and the data communication device, information transmitted from the server device to the data communication device via the Internet is transmitted from the data communication device to the base station via the connection. And transmitted from the base station to the calling portable information terminal via a wireless link.

[0004] The data communication service using the mobile communication system is very convenient because it can send and receive e-mails and browse Web information on the Internet anytime and anywhere.

Recently, in this type of mobile data communication system, a mobile terminal device is provided with a plurality of wireless data communication protocols that use different numbers of wireless channels, and the mobile terminal device can select a desired wireless data communication protocol from these wireless data communication protocols. It has been proposed by the present inventors that wireless data communication is performed by selecting the above protocol. For example, PHS
Is a protocol that performs wireless data communication at 32 kbps using one wireless communication channel and 64 kbps using two wireless communication channels.
A protocol for performing wireless data communication of s is prepared, and the user of the mobile terminal device selects a desired protocol from these protocols and requests the base station to perform wireless data communication.

However, the protocol requested by the user of the mobile terminal device is not always accepted by the base station. For example, even if the mobile terminal device requests a protocol using two wireless channels, the number of available wireless communication channels is one.
If there is only a channel, the base station rejects this request. In this case, the user of the mobile terminal device changes the request protocol to, for example, a protocol that uses one wireless communication channel, and calls again. If the re-requested protocol is also rejected, the call is abandoned, or another communicable protocol is selected and the call is made again. That is, the protocol request from the mobile terminal device to the base station is performed by trial and error.

For this reason, especially in a situation where the radio section is congested, it may take a long time before a radio link is formed between the mobile terminal apparatus and the base station. In addition, since the user of the mobile terminal device specifies the protocol at his / her own discretion, the operational burden on the user is large, and particularly an unfamiliar user may give up communication.

[0008]

As described above, when a mobile data communication system intends to perform communication by selectively using a plurality of wireless data communication protocols, a request for selecting a wireless data communication protocol is made by trial and error. Therefore, efficient call connection could not be performed, and the burden on the user in operation was large.

The present invention has been made in view of the above circumstances. It is an object of the present invention to enable a request for selecting a wireless data communication protocol to be made efficiently,
It is an object of the present invention to provide a mobile data communication system, a base station device and a mobile terminal device, which greatly reduce the operational burden on the user of the mobile terminal device.

[0010]

According to a first aspect of the present invention, there is provided a mobile station in which a base station apparatus and a mobile terminal apparatus have a plurality of wireless data communication protocols having different required wireless channel capacities. In a data communication system, a base station device includes a protocol selection unit and a protocol notification unit. Then, when the mobile terminal device requests mobile data communication, the protocol selecting means selects an available wireless data communication protocol from the plurality of wireless data communication protocols based on the free capacity of the wireless channel. Then, the selected wireless data communication protocol is notified to the requesting mobile terminal device by the protocol notification means. Also, the mobile terminal device is provided with reconnection control means, and when the wireless data communication protocol different from the request is notified from the base station apparatus to the mobile data communication request by the reconnection control means, this notification is sent. A reconnection procedure for requesting mobile data communication according to the wireless data communication protocol is performed.

Therefore, according to the present invention, for example, if the wireless data communication protocol requested by the mobile terminal device cannot be accepted due to a lack of a free wireless channel, a protocol not to be used, or the like, the base station At
A currently usable wireless data communication protocol is selected from a plurality of wireless data protocols and notified to the requesting mobile terminal device. The mobile terminal device requests the wireless data communication protocol notified from this base station. Is automatically re-established.

Therefore, trial and error negotiations are not repeated when establishing a wireless link between the mobile terminal device and the base station, thereby shortening the time required for connecting the wireless link, and Useless use of the control channel is suppressed. In addition, the user of the mobile terminal device does not need to determine the wireless data communication protocol that can be used by himself and perform the designation operation, and the operational burden is reduced.

According to another aspect of the present invention, when the base station apparatus needs to communicate with another mobile terminal apparatus during the mobile data communication with the mobile terminal apparatus, the base station apparatus is used for the mobile data communication. Determination means for determining whether or not the wireless data communication protocol can be maintained. If the determination means determines that the wireless data communication protocol cannot be maintained, an alternative wireless data communication protocol is selected from a plurality of wireless data communication protocols. Then, this is notified to the communicating mobile terminal device, and the mobile terminal device is provided with reconnection control means, and an alternative wireless data communication protocol is notified from the base station device during the mobile data communication. In such a case, a reconnection procedure for switching to the mobile data communication according to the notified alternative wireless data communication protocol is executed.

Therefore, according to the present invention, for example, when a call is generated from another mobile terminal device during mobile data communication, if the wireless data communication protocol during the communication cannot be maintained, the mobile data communication is performed from the base station device. An alternative wireless data communication protocol is notified to the mobile terminal device that is communicating, and the mobile terminal device once terminates communication and then performs a recall for requesting communication using the alternative wireless data communication protocol. That is, the wireless data communication protocol of the communicating mobile terminal device is automatically changed in accordance with the availability of the wireless channel and the occurrence of the call request.

[0015] Therefore, for example, when a new call connection request is generated in a state where the radio channel is less vacant, the radio channel can be allocated to the requesting mobile terminal device. Radio resources can be used effectively.

According to still another aspect of the present invention, a base station apparatus monitors the free space of a radio channel during mobile data communication with a mobile terminal apparatus, and based on the monitoring result, sets a radio channel for the mobile data communication during the communication. A determining means for determining whether or not the capacity can be increased; if the determining means determines that the capacity can be increased, transmission is performed from the wireless data communication protocol in use from among the plurality of wireless data communication protocols; A high-performance wireless data communication protocol is selected and notified to the communicating mobile terminal device, and the mobile terminal device is provided with reconnection control means. When the data communication protocol is notified, a reconnection procedure for switching to the mobile data communication according to the notified wireless data communication protocol is executed. It is obtained by way.

Therefore, according to the present invention, for example, even if mobile data communication is performed by a wireless data communication protocol using a small number of wireless channels at the beginning of communication, an empty wireless channel is generated during communication and this empty channel is generated. Becomes available, the wireless data communication protocol during communication is changed to a protocol that uses more wireless channels. For this reason, the transmission efficiency of mobile data communication can be improved by using the idle radio channel more effectively.

In each of the above inventions, the wireless data communication protocol selected by the protocol selecting means is
It is configured to notify using a procedure for disconnecting a wireless link with a mobile terminal device. In this manner, the protocol can be notified using the existing disconnection procedure without newly providing a special procedure for notifying the protocol.

Further, after securing a free radio channel capacity necessary for making a call connection with at least one mobile terminal device, a radio data communication protocol to be notified to the mobile terminal device is selected. In this way, a new call connection request from the mobile terminal device can be accepted at any time.

Further, each of the above-mentioned inventions provides a base station apparatus and a mobile terminal apparatus with a wireless packet communication protocol using a wireless control channel in addition to a wireless data communication protocol using a wireless communication channel. In the means, when the capacity of the wireless communication channel necessary for performing mobile data communication by the wireless data communication protocol is insufficient, the wireless packet communication protocol using the wireless control channel is selected. By doing so, it becomes possible to perform wireless packet communication using the control channel even when the wireless communication channel is completely free.

[0021]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a mobile data communication system according to an embodiment of the present invention,
CS1 to CSn indicate PHS base stations. These base stations CS1 to CSn are geographically distributed in a service area covered by the system, and one or a plurality of them form a wireless area.

Each of the mobile terminals PS1 to PSm is connected to the nearest base station via a radio line in a cell formed by each of the base stations CS1 to CSn. As a wireless access method between the base station and the mobile terminal device, for example, TDMA-TDD (Time Division Multiple Access)
-Time Division Duplex) method is used. The mobile terminal devices PS1 to PSm include a mobile information terminal having a data communication function and a wireless access function, and a mobile terminal device having a personal computer PC connected to the mobile phone, in addition to a mobile phone having only a call function.

Each of the base stations CS1 to CSn is connected to an I 'interface network (hereinafter referred to as I') via a subscriber line.
(Referred to as a network) IN2 and connected to a dedicated line network PN via a dedicated line. I 'net IN2 is PHS
And a public network composed of a circuit switching network together with the integrated services digital network (ISDN) IN1. Many wired terminal devices (not shown) are connected to the ISDN network IN1. The leased line network PN forms a packet network. The packet exchange is performed according to the protocol specified in 25.

A gateway GW as a data communication device is connected to the ISDN network IN1 and the private line network PN, and a server device AS is connected to the gateway GW via the Internet, for example. Server device AS
Has a function as a mail server when e-mail is transmitted between the mobile terminal devices PS1 to PSm and the wired terminal device, and transmits Web information such as news and advertisements to the mobile terminal devices PS1 to PSm and the wired terminal device. Has a function as a content server for notifying the user. For information transmission between the gateway GW and the server device AS,
The TCP / IP protocol is used.

It should be noted that the gateway GW and the server device AS
Can be connected via a network, and further, a function as a server device can be implemented in the gateway GW.

In the mobile data communication system as described above, the base stations CS1 to CSn and the mobile terminal devices PS1 to PSm use, for example, a protocol A for performing wireless data communication of 32 kbps using one wireless communication channel, 64 using two wireless communication channels
Protocol B for performing wireless data communication of kbps and Protocol C for performing wireless packet communication using a control channel
, And a desired protocol can be selected from these protocols A, B, and C to perform wireless data communication.

As a form of the data communication system, ISDN
A data communication method performed, for example, with a wired terminal device (not shown) via the network IN1, and a data communication method performed, for example, with a packet-switchable terminal device via the leased line network PN. There is.

Hereinafter, the configuration of each device constituting the system of the present embodiment will be described in detail. First, the mobile terminal device PS1
~ PSm is configured as follows. FIG. 2 is a functional block diagram showing the configuration.

The mobile terminals PS1 to PSm include a radio unit 1 having an antenna 11, a modem unit 2, and a TDMA unit 3.
, A communication unit 4, a control unit 5, an information storage unit 6, a data communication unit 7, a display unit 8, and a key input unit 9.

That is, the radio carrier signals arriving from the base stations CS1 to CSn are received by the antenna 11 and then input to the receiving unit 13 via the high frequency switch (SW) 12 of the radio unit 1. In the receiving unit 13, the received radio carrier signal is mixed with a local oscillation signal generated from the frequency synthesizer 14 and down-converted into a received intermediate frequency signal. The local oscillation signal frequency generated from the frequency synthesizer 14 is set to a value corresponding to the radio channel frequency according to an instruction from the control unit 5. Also, the radio unit 1 includes a reception field strength detection unit (RS
SI) 16 are provided. The reception field strength detection section 16 detects the reception field strength of the radio carrier signals arriving from the base stations CS1 to CSn, and notifies the control section 5 of the detected value, for example, to determine and display the reception quality. .

The received intermediate frequency signal output from the receiving unit 13 is input to the demodulation unit 21 of the modem unit 2. The demodulation section 21 performs digital demodulation of the received intermediate frequency signal, thereby reproducing a digital demodulated signal.

The TDMA decoding section 31 of the TDMA section 3
Separates the digital demodulated signal for each reception time slot. If the data of the separated slot is audio data, the audio data is transmitted to the interface unit 4.
To enter. On the other hand, if the data of the separated slot is packet data or control data, these data are input to the data communication unit 7.

The communication unit 4 is provided with an ADPCM (Adaptive Diffe
rential Pulse Code Modulation) Transcoder 41
, A PCM codec 42, a speaker 43, and a microphone 44. The ADPCM transcoder 41 decodes the audio data output from the TDMA decoding unit 31. The PCM codec 42 uses the A
The digital audio signal output from the DPCM transcoder 41 is converted into an analog signal, and this audio signal is output from the speaker 43 as loudspeaker.

The data communication section 7 receives the data output from the TDMA decoding section 31 and supplies the data to the control section 5. If the received data is control data, the control unit 5 analyzes the control data and performs necessary control.
On the other hand, if the received data is packet data arriving from a server device or the like, the packet data is depacketized, stored in the information storage unit 6, and supplied to the display unit 8 including, for example, a liquid crystal display (LCD). Display.

On the other hand, the user's voice signal input to the microphone 44 is PCM-coded by the PCM codec 42 and then compression-coded by the ADPCM transcoder 41. Then, the encoded audio data is TDM
It is input to the A encoding unit 32. The control data and packet data output from the control unit 5 are input to the TDMA encoding unit 32 via the data communication unit 7.

[0036] The TDMA encoding unit 32 uses the ADP.
The digital audio data of each channel output from the CM transcoder 41 and the control data and packet data output from the data communication unit 7 are inserted into a transmission time slot designated by the control unit 5 and multiplexed. The modulation unit 22 digitally modulates the transmission intermediate frequency signal with the multiplexed digital communication signal output from the TDMA encoding unit 32, and inputs the modulated transmission intermediate frequency signal to the transmission unit 15.

The transmitting section 15 mixes the modulated transmission intermediate frequency signal with a local oscillation signal generated from the synthesizer 14, upconverts the signal into a radio carrier frequency, and further amplifies the signal to a predetermined transmission power level. The radio carrier signal output from the transmitting unit 15 is transmitted from the antenna 11 via the high frequency switch 12 to the base stations CS1 to CSn.
Sent to

The control unit 5 has a microcomputer as a main control unit, and includes a protocol notification receiving unit 51 and a reconnection control unit 52 as control functions according to the present invention.

The protocol notification receiving means 51, during execution of the call connection process or during mobile data communication, transmits a base station C to be described later.
When protocol information is transmitted from S1 to CSn using the disconnection notification, the protocol information is received.

When the protocol information receiving means 51 receives the disconnection notification and the protocol information, the reconnection control means 52 transmits a call connection request for requesting data communication based on the newly notified protocol information to the base station. It transmits to the stations CS1 to CSn.

On the other hand, the base stations CS1 to CSn are configured as follows. FIG. 3 is a circuit block diagram showing the configuration. The base stations CS1 to CSn include a radio unit 10 having an antenna 111, a modem unit 20, a TDMA unit 30, an interface unit 40, a control unit 50, and an information storage unit 60.
And a data communication unit 70.

That is, the radio carrier signals arriving from the mobile terminal devices PS1 to PSm are received by the antenna 111 and then input to the receiving unit 113 via the high frequency switch (SW) 112 of the radio unit 10. In the receiving section 113, the received radio carrier signal is mixed with a local oscillation signal generated from the frequency synthesizer 114 and down-converted into a received intermediate frequency signal. In addition,
The frequency of the local oscillation signal generated from the frequency synthesizer 114 is controlled by the control unit 5 according to the radio channel frequency.
Indicated from 0. Further, the radio unit 10 is provided with a reception field strength detection unit (RSSI) 116. In the reception electric field strength detection unit 116, the mobile terminal devices PS1 to PS
The received electric field strength of the wireless carrier signal arriving from m is detected, and the detected value is notified to the control unit 50 for an idle channel search, handover control of the mobile terminal device, and the like.

The received intermediate frequency signal output from the receiving section 113 is input to the demodulation section 221 of the modem section 20. The demodulation section 221 performs digital demodulation of the received intermediate frequency signal, thereby reproducing a digital demodulated signal.

The TDMA decoding section 33 of the TDMA section 30
1 separates the digital demodulated signal for each reception time slot. If the data of the separated slot is audio data, the audio data is input to the interface unit 40. On the other hand, if the data of the separated slot is packet data or control data, these data are input to the data communication unit 70.

The interface unit 40 has an ADPCM (Ad
aptive Differential Pulse Code Modulation) transcoder 441, public line interface 442,
And a dedicated line interface 443.

The ADPCM transcoder 441 decodes the audio data output from the TDMA decoding section 331. The decoded digital audio signal is transmitted from the public line interface 442 to the I 'network IN2. The public line interface 442 performs a call connection process for the I 'network IN2 according to an instruction from the control unit 50. The leased line interface 443 performs processing for opening a connection for packet communication to the leased line network PN, etc., in accordance with an instruction from the control unit 50.

The data communication unit 70 is connected to the mobile terminal PS1.
If the data arriving from .about.PSm is control data addressed to the own station, the control data is input to the control unit 50. Control unit 5
0 performs processing for opening a connection for packet communication using the leased line network PN with the gateway GW based on the control data. On the other hand, the mobile terminal device PS1
If the data arriving from .about.PSm is packet data addressed to the outside, the data communication unit 70 sends the packet data to the leased line network PN via the leased line interface 443.

On the other hand, a digital communication signal arriving from the I 'network IN2 is received by the public line interface 442. If the digital communication signal is audio data, the digital communication signal is subjected to compression encoding processing by the ADPCM transcoder 441 and is input to the TDMA encoding unit 332. On the other hand, if the digital communication signal is control data, it is input to the data communication unit 70. Private network P
The packet data arriving from N is input to the data communication unit 70 via the dedicated line interface 443.

When the destination of the input data is the mobile terminal device PS1 to PSm, the data communication unit 70 inputs the data to the TDMA encoding unit 332. On the other hand, if the input data is control data addressed to the own station, the control data is input to the control unit 50. The control unit 50
The input control data is analyzed to perform various controls.
The control unit 50 outputs control data addressed to the mobile terminal devices PS1 to PSm to the TDMA encoding unit 332 via the data communication unit 70.

[0050] The TDMA encoding unit 332 converts the AD
The digital voice data of each channel output from the PCM transcoder 441 and the control data and packet data output from the data communication unit 70 are inserted into the transmission time slot designated by the control unit 50 and multiplexed. The modulation section 222 digitally modulates the transmission intermediate frequency signal with the multiplexed digital communication signal output from the TDMA encoding section 332, and inputs the modulated transmission intermediate frequency signal to the transmission section 115.

The transmitting section 115 mixes the modulated transmission intermediate frequency signal with the local oscillation signal generated from the synthesizer 114, upconverts the signal into a radio carrier frequency, and further amplifies the signal to a predetermined transmission power level. The wireless carrier signal output from the transmitting unit 115 is transmitted from the antenna 111 to the mobile terminal devices PS1 to PSm via the high frequency switch 112.

The control unit 50 has a microcomputer as a main control unit, and includes, as control functions according to the present invention, a call connection control unit 551, a protocol change determination unit 552, a protocol selection unit 553,
Protocol notification control means 554.

The call connection control means 551 is provided for the mobile terminal device P
When a call connection request arrives from S1 to PSm and the public networks IN1 and IN2 or the leased line network PN, a free wireless communication channel is selected and transmitted to the mobile terminal devices PS1 to PSm.
And a predetermined procedure such as synchronization and authentication is executed to establish a wireless link with the mobile terminal devices PS1 to PSm.

The protocol change judging means 552, when a call request arrives from another mobile terminal device in a state where mobile data communication is being performed with an arbitrary mobile terminal device, determines the current available channel. Based on the number, it is determined whether or not the wireless data communication protocol used for the mobile data communication can be maintained. At the same time, while mobile data communication is being performed with an arbitrary mobile terminal device,
The increase / decrease of the number of free channels of the wireless communication channel is monitored, and when the number of free channels increases due to release of the wireless communication channel, etc., whether the number of wireless communication channels for the mobile data communication during the communication can be increased or not is possible. Is determined.

When a call connection request arrives from the mobile terminal devices PS1 to PSm, the protocol selection means 553 determines whether or not the wireless data communication protocol transmitted with the call connection request can be used at the present time. The determination is made based on the number of available channels. Then, when the wireless communication protocol cannot be used, an available protocol is selected from other wireless data communication protocols. In addition, when the protocol change determination unit 552 determines that the wireless data communication protocol in use cannot be maintained, and when it is determined that the number of wireless communication channels for mobile data communication during communication can be increased, Also, select a usable protocol from other wireless data communication protocols.

When the protocol selection means 553 selects a wireless data communication protocol to be changed, the protocol notification control means 554 includes information for notifying the wireless data communication protocol in the disconnection notification and transmits the information to the mobile terminal apparatus. Send to PS1 to PSm.

Next, the operation of the system configured as described above will be described. First, the operation when the mobile terminal devices PS1 to PSm request a call connection will be described using the flowcharts shown in FIGS. 4 and 6 and the sequence diagrams shown in FIGS.

Now, for example, in the mobile terminal device PS1,
It is assumed that the user performs a calling operation for mobile data communication, and at this time, as shown in FIG. 4, a wireless data communication protocol A using two wireless communication channels is specified in step 4a. Then, a call connection request for requesting the wireless data communication protocol A is transmitted from the mobile terminal device PS1 to the base station CS1.

When the base station CS1 receives a call connection request from the mobile terminal device PS1, the base station CS1 transmits the call connection request in step 6
a, and the connection type is determined in step 6b. If the requested connection type is data communication, a protocol is selected in step 6c. That is, the number of available wireless communication channels at the present time is detected, and based on the number of autumn channels, it is determined whether or not the wireless data communication protocol A requested by the mobile terminal device PS1 can be used.

If the number of available channels is sufficient and the protocol A can be used, the process proceeds to step 6d, and the requesting mobile terminal device PS1 is given two radio communication channels required for the protocol A. Channel allocation and establishment of a data communication connection with the mobile terminal device PS1. At the same time, the base station CS1 sends a call connection request to the gateway GW via the leased line network PN. Upon receiving a call connection request for a call, the gateway GW opens an SVC (Switching Virtual Circuit) via the leased line network PN with the requesting base station CS1.

When a connection for data communication is established with the gateway GW, the base station CS1 sends a connection response to the mobile terminal device PS1 in step 6e, and thereafter performs a data relay operation in step 6f. . The mobile terminal device PS1 determines in step 4b that the base station C
Upon receiving the connection response from S1, the data communication operation is started in step 4g. FIG. 8 is a sequence diagram showing an operation when the use of the wireless data communication protocol A requested by the mobile terminal device PS1 is permitted as described above.

On the other hand, if the number of available wireless communication channels is only one, and the mobile terminal P
It is assumed that the protocol A requested by S1 cannot be used. In this case, the base station CS1 determines in step 6c
Select another available wireless data communication protocol.
For example, here, the wireless data communication protocol B using one wireless communication channel is selected. Then, the process proceeds to step 6g, in which the information designating the wireless data communication protocol B is inserted as a disconnection notification into the disconnection notification and transmitted.

When the disconnection notification arrives from the base station CS1 after transmitting the call connection request, the mobile terminal device PS1 shifts from step 4b to step 4c, where it judges the reason for disconnection of the disconnection notification. Here, since the designation information of the wireless data communication protocol B is inserted as the reason for disconnection, the mobile terminal device PS1 proceeds to step 4e to extract the wireless data communication protocol B, and the newly specified wireless data communication protocol B is assigned in step 4f. A call connection request for requesting data communication according to the wireless data communication protocol B is transmitted to the base station CS1.

When the base station CS1 receives a call connection request from the mobile terminal device PS1, the base station CS1 executes step 6 as described above.
From a to step 6e, a process for establishing a connection for data communication with the mobile terminal device PS1 and with the gateway GW is executed, and when the connection is established, a data relay process is performed in step 6f.

FIG. 9 shows the mobile terminal device PS1 described above.
FIG. 7 is a sequence diagram showing an operation when the use of the wireless data communication protocol A requested by the user is rejected and the base station CS1 specifies another available wireless data communication protocol B.

In the determination in step 6c, if there is no available wireless communication channel and there is no usable wireless data communication protocol, the base station CS1
Sends a disconnection notification including the connection rejection as the disconnection reason in step 6g. Upon receiving the disconnection notification, the mobile terminal device PS1 proceeds from step 4c to step 4d, where it abandons the call connection request and returns to the standby state.

Next, the operation when the protocol is changed during the data communication will be described with reference to the flowcharts shown in FIGS. 5, 6, and 7, and the sequence diagrams shown in FIGS.

In a state where the mobile terminal device PS1 is performing data communication with the base station CS1 using the wireless data communication protocol B, another mobile terminal device PS2 now makes a call as shown in FIG. Assume that the requested call connection request has been transmitted.

Upon receiving the call connection request at step 6a, the base station CS1 determines the connection type at step 6b,
Here, since it is a call request, the flow shifts to step 6h to determine whether or not there is an empty channel in the wireless communication channel. If there is an available channel, a process for connecting a communication path with the mobile terminal device PS2 that has issued the call request is performed in step 6i. In addition, public networks IN1 and I
A call connection request to the terminal device of the other party is transmitted to N2. Then, when a communication path is established with the partner terminal device, a connection response is sent in step 6j to the mobile terminal device PS2.
Send to After receiving the connection response, the mobile terminal device PS2 can communicate with the terminal device of the other party.

On the other hand, in step 6h,
It is assumed that there is no available wireless communication channel. Then, the base station CS1 proceeds to step 6k, where it determines whether there is a mobile terminal device that is performing communication using the wireless communication channel. If there is no mobile terminal device currently performing mobile data communication, it is determined that there is no wireless communication channel to be assigned to the mobile terminal device PS2, and a connection rejection is transmitted to the calling mobile terminal device PS2 in step 6p.

However, in this case, since the mobile terminal device PS1 is communicating using the radio communication channel, the base station CS1
Determines that there is a possibility that the wireless communication channel assigned to the mobile terminal device PS1 can be accommodated in the mobile terminal device PS2, and proceeds to step 6q to select an alternative protocol. For example, if the mobile terminal device PS1 performing data communication has a wireless packet communication protocol,
Select a wireless packet communication protocol. Then, a disconnection notification including the specified information of the wireless packet communication protocol as a disconnection reason is transmitted to the mobile terminal apparatus PS1 during data communication.
And after this transmission, the wireless communication channel allocated to the mobile terminal device PS1 is released. At this time, the data communication connection established between the base station CS1 and the gateway GW is kept as it is.

Then, the base station CS1 allocates the released radio communication channel to the calling mobile terminal device PS2, and further requests the public networks IN1 and IN2 for a call connection to the terminal device of the other party. When a communication path is formed between the mobile terminal device and the terminal device, a call connection response is returned to the mobile terminal device PS2 that is the calling source. Upon receiving the call connection response, the mobile terminal device PS2, which is the calling source, enters a callable state thereafter.

On the other hand, the mobile terminal device P during data communication
S1 is step 5a during data communication as shown in FIG.
When a disconnection notification is received at step 5b, the reason for disconnection is determined at step 5b. In this case, since the designation information of the wireless packet communication protocol is inserted as the reason for disconnection, the process proceeds to step 5d, where the designated protocol is detected, and step 5e is performed.
Transmits a call connection request for requesting data communication according to the specified wireless packet communication protocol to the base station CS1.

When the base station CS1 receives a call connection request from the mobile terminal device PS1, the base station CS1 proceeds from step 6a to step 6
In step e, a wireless link for wireless packet communication using a control channel is established with the mobile terminal device PS1, and this wireless link is connected to a connection for data communication established with the gateway GW.

Accordingly, thereafter, the mobile terminal device PS1 continues data communication with the gateway Gw using the wireless packet communication protocol. FIG. 10 shows a sequence of an operation of changing the wireless data communication protocol A to the wireless packet communication protocol described above.

In the state where data communication is being performed using the wireless packet communication protocol as described above, the mobile terminal device PS2 or another mobile terminal device PS
Ends the call and releases the wireless communication channel. At this time, upon receiving the call disconnection request from the mobile terminal device PS2 or PSi in step 7a as shown in FIG. 7, the base station CS1 returns a call disconnection response to the mobile terminal device PS2 or PSi in step 7b. Then, in step 7c, it is determined whether there is a mobile terminal device performing data communication.

If the result of this determination is that there is no mobile terminal device currently performing data communication, the process is terminated as it is. However, here, since mobile terminal device PS1 is performing data communication, base station CS1
Shifts to step 7d, where the wireless data communication protocol B using the released wireless communication channel is selected. Then, the process shifts from step 7e to step 7f, where a disconnection notification using the wireless data communication protocol B as a disconnection reason is transmitted to the mobile terminal device PS during data communication.
Send to 1. Then, the control channel used by the mobile terminal device PS1 is released. At this time, the base station C
The data communication connection established between S1 and the gateway GW is kept as it is.

When the disconnection notification arrives from the base station CS1 during data communication, the mobile terminal device PS1 designates the wireless data communication protocol under communication from the base station CS1 as shown in steps 5a to 5f of FIG. The call connection request processing for changing to the wireless data communication protocol is executed again.

Thus, the protocol of the mobile terminal device PS1 is changed from the wireless packet communication protocol using the control channel to the wireless data communication protocol B using one wireless communication channel. Then, the data communication is continued. FIG. 11 is a sequence diagram showing control for changing the above-described wireless packet communication protocol to the wireless data communication protocol B.

As described above, in this embodiment, when a call connection request is issued from each of the mobile terminal devices PS1 to PSm, the base stations CS1 to CSn use the radio communication channel vacancy at that point in time. It is determined whether the requested wireless data communication protocol can be used. And
If it is impossible, a usable wireless data communication protocol is selected from a plurality of prepared wireless data communication protocols, and this is included in the disconnection notification and notified to the mobile terminal devices PS1 to PSn. Mobile terminal devices PS1 to PS
When the disconnection notification arrives and the disconnection reason is specified by the protocol, m transmits a call connection request for requesting data communication according to the specified protocol.

Therefore, according to the present embodiment, the mobile terminal devices PS1 to PSm automatically make a recall according to the protocol specified by the base stations CS1 to CSn. Therefore, the mobile terminal devices PS1 to PSm and the base stations CS1 to CS1
Trial-and-error negotiation is not repeated when establishing a wireless link with CSn, thereby reducing the time required for connecting the wireless link and suppressing unnecessary use of the control channel. Further, the user of each of the mobile terminal devices PS1 to PSm does not need to determine the wireless data communication protocol that can be used by himself and perform the designation operation, thereby greatly reducing the operation burden.

Further, in this embodiment, when a call connection request is issued from another mobile terminal device while any mobile terminal device is performing data communication, and there is no wireless communication channel to be assigned to this mobile terminal device, Further, the protocol of the mobile terminal device performing the data communication is changed to a wireless packet communication protocol using a control channel.

Accordingly, the wireless data communication protocol of the mobile terminal device in communication is automatically changed in accordance with the availability of the wireless channel and the occurrence of the call request. When a new call connection request is issued in a small number of states, it becomes possible to allocate a radio channel to the requesting mobile terminal device, and as a result, finite radio resources can be used effectively.

Further, in this embodiment, when an arbitrary mobile terminal device is performing data communication and a wireless communication channel becomes available, the wireless packet communication used by the mobile terminal device during data communication is performed. The protocol is changed to the wireless data communication protocol B using the empty wireless communication channel.

Therefore, it becomes possible to use the empty radio communication channel more effectively, and thereby, it is possible to maintain higher data transmission efficiency. In addition, there is no need to worry that the mobile terminal devices PS1 to PSm occupy the control channel for a long period of time, which alleviates troubles that may hinder a call from another mobile terminal device.

In this embodiment, the base stations CS1 to CS1
When the wireless data communication protocol is designated from the CSn to the mobile terminal devices PS1 to PSm, the disconnection notification is used. Therefore, a special procedure for notifying the protocol is not newly provided, and the existing disconnection procedure is used. Can be used to notify the protocol.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, an example has been described in which two types of wireless data communication protocols A and B using a wireless communication channel and a wireless packet communication protocol using a control channel are selectively used. From among three or more types of wireless data communication protocols using different numbers of channels, a protocol having the largest available transmission capacity at that time may be selected.

Further, the mobile terminal device may be provided with a function of displaying the currently selected and currently communicating protocol using the protocol name or its number or a mark. In this way, the user can always clearly know the protocol being used. This is particularly effective when the protocol is changed from the base station.

In addition, the type and configuration of the mobile communication system,
The configurations of the mobile terminal device and the base station, the protocol selection notification procedure and its control content, the protocol change procedure and its control content, and the like can be variously modified without departing from the gist of the present invention.

[0090]

As described in detail above, the present invention relates to a mobile data communication system in which a base station apparatus and a mobile terminal apparatus have a plurality of wireless data communication protocols having different required wireless channel capacities. In the base station device,
When the mobile terminal device requests mobile data communication, an available wireless data communication protocol is selected from the plurality of wireless data communication protocols based on the available capacity of the wireless channel, and the selected wireless data communication protocol is selected. The communication protocol is notified to the requesting mobile terminal device, and in the mobile terminal device, when a request for mobile data communication is notified of a wireless data communication protocol different from the request from the base station device, the notification is transmitted. A reconnection procedure for requesting mobile data communication according to the wireless data communication protocol is executed.

Therefore, according to the present invention, a mobile data communication system and its base can efficiently make a request to select a wireless data communication protocol and greatly reduce the operational burden on the mobile terminal user. A station device and a mobile terminal device can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a mobile data communication system according to the present invention.

FIG. 2 is a circuit block diagram showing a configuration of a mobile terminal device in the system shown in FIG.

FIG. 3 is a circuit block diagram showing a configuration of a base station in the system shown in FIG.

FIG. 4 is a flowchart showing an operation procedure and contents of the mobile terminal apparatus shown in FIG. 2 at the time of a call connection request.

FIG. 5 is a flowchart showing an operation procedure and contents of the mobile terminal device shown in FIG. 2 during mobile data communication.

FIG. 6 is a flowchart showing an operation procedure and contents of the base station shown in FIG. 3;

7 is a flowchart showing an operation procedure and its contents when the base station shown in FIG. 3 is disconnected.

FIG. 8 is a sequence diagram showing a normal operation at the time of a call connection request in the system shown in FIG. 1;

FIG. 9 is a sequence diagram showing a protocol change operation at the time of a call connection request in the system shown in FIG. 1;

FIG. 10 is a sequence diagram showing an example of a protocol change operation at the time of communication in the system shown in FIG. 1;

FIG. 11 is a sequence diagram showing another example of the protocol change operation at the time of communication in the system shown in FIG. 1;

[Explanation of symbols]

 CS1 to CSn Base stations PS1 to PSm Mobile terminal device IN1 ISDN network IN2 I 'network PN Private line network AS Server device GW Gateway 1,10 Radio unit 2,20 Modem unit 3,30 TDMA unit 4 Talk unit 5, 50 Control unit 6, 60 Information storage unit 7, 70 Data communication unit 8 Display unit 9 Input unit 11, 111 Antenna 12, 112 High frequency switch (SW) 13, 113 receiving unit 14, 114 frequency synthesizer 15, 115 transmitting unit 16, 116 receiving electric field strength detecting unit (RSSI) 21, 221 demodulating unit 22, 222 modulating unit 31, 331 TDMA decoding unit 32, 332 ... TDMA encoding section 40 ... Interface sections 41,441 ... ADPCM transcoder 42 ... PCM codec 43 ... Speed 44 ... microphone 51 ... protocol notification receiving unit 52 ... reconnection control unit 442 ... public line interface 443 ... service line interface 551 ... call connection control unit 552 ... protocol change determination unit 553 ... protocol selection means 554 ... protocol notification control means

Claims (10)

[Claims] At least one base station device forming a radio area, a plurality of mobile terminal devices connected to the base station device via a radio channel, and a communication network for the base station device A mobile data communication system comprising: a data communication device to be connected; a data communication connection established between the data communication device and the mobile terminal device; and data transmission using the connection. The station device and the mobile terminal device have a plurality of wireless data communication protocols having different required wireless channel capacities, and the base station device, when the mobile terminal device requests mobile data communication,
Protocol selecting means for selecting an available wireless data communication protocol from the plurality of wireless data communication protocols based on the free capacity of the wireless channel; anda wireless data communication protocol selected by the protocol selecting means, Protocol notifying means for notifying the requesting mobile terminal device, the mobile terminal device, when a wireless data communication protocol different from the request is notified from the base station device to the mobile data communication request, A mobile data communication system comprising reconnection control means for executing a reconnection procedure for requesting mobile data communication according to the notified wireless data communication protocol. 2. At least one base station device forming a wireless area, a plurality of mobile terminal devices connected to the base station device via a radio channel, and a communication network for the base station device. A mobile data communication system comprising: a data communication device to be connected; a data communication connection established between the data communication device and the mobile terminal device; and data transmission using the connection. The station device and the mobile terminal device have a plurality of wireless data communication protocols that require different wireless channel capacities, and the base station device communicates with another mobile terminal device during mobile data communication with the mobile terminal device. A determination unit that determines whether the wireless data communication protocol used for the mobile data communication can be maintained when it is necessary to perform communication by A protocol selecting means for selecting an alternative wireless data communication protocol from the plurality of wireless data communication protocols when the determining means determines that the wireless data communication cannot be maintained; and an alternative wireless data communication selected by the protocol selecting means. A protocol notifying unit for notifying a protocol to the communicating mobile terminal device, wherein the mobile terminal device is notified of an alternative wireless data communication protocol from the base station device during mobile data communication. A mobile data communication system comprising reconnection control means for executing a reconnection procedure for switching to mobile data communication according to the notified alternative wireless data communication protocol. 3. At least one base station device forming a wireless area, a plurality of mobile terminal devices connected to the base station device via a wireless channel, and a communication network for the base station device. A mobile data communication system comprising: a data communication device to be connected; a data communication connection established between the data communication device and the mobile terminal device; and data transmission using the connection. The station device and the mobile terminal device have a plurality of wireless data communication protocols having different wireless channel transmission capacities, the base station device monitors the free capacity of the wireless channel during mobile data communication with the mobile terminal device, Determining means for determining, based on the monitoring result, whether the radio channel capacity for the mobile data communication during the communication can be increased; Protocol selecting means for selecting, from the plurality of wireless data communication protocols, a wireless data communication protocol having a higher transmission capability than the wireless data communication protocol being used, when it is determined by the determining means that the increase is possible; And a protocol notifying unit for notifying the communicating mobile terminal device of the wireless data communication protocol selected by the above, wherein the mobile terminal device is notified of the wireless data communication protocol from the base station device during mobile data communication. A reconnection control means for executing a reconnection procedure for switching to the mobile data communication according to the notified wireless data communication protocol. 4. The protocol notification unit notifies the wireless data communication protocol selected by the protocol selection unit using a procedure for disconnecting a wireless link with a mobile terminal device. The mobile data communication system according to any one of claims 1 to 3, wherein: 5. A wireless data communication protocol to be notified to a mobile terminal device after securing a free radio channel capacity necessary for making a call connection with at least one mobile terminal device. 4. The mobile data communication system according to claim 1, wherein the mobile data communication system is selected. 6. The base station apparatus and the mobile terminal apparatus have at least one wireless data communication protocol using a wireless communication channel and a wireless packet communication protocol using a wireless control channel. The wireless packet communication protocol using a wireless control channel is selected when a wireless communication channel has insufficient free space required for performing mobile data communication according to a wireless data communication protocol. The mobile data communication system according to any one of claims 1 to 3. 7. A mobile terminal device connected via a wireless line and connected to a data communication device via a communication network, using a connection established between the mobile terminal device and the data communication device. In a base station device relaying data communication performed according to a protocol selected from a plurality of wireless data communication protocols, when the mobile terminal device requests mobile data communication,
Protocol selecting means for selecting an available wireless data communication protocol from the plurality of wireless data communication protocols based on the free space of the wireless channel; and requesting the wireless data communication protocol selected by the protocol selecting means. A base station comprising a protocol notification unit for notifying the original mobile terminal unit and executing a reconnection procedure for requesting the base station unit to request mobile data communication according to the notified wireless data communication protocol. apparatus. 8. A connection between the mobile terminal device and the data communication device, wherein the connection between the mobile terminal device and the data communication device is established via a communication network. A base station device that relays data communication performed according to a protocol selected from a plurality of wireless data communication protocols, and performs communication with another mobile terminal device during mobile data communication with the mobile terminal device A determining unit for determining whether a wireless data communication protocol used for the mobile data communication can be maintained, when the need arises; and Protocol selection means for selecting an alternative wireless data communication protocol from data communication protocols; and an alternative wireless communication protocol selected by the protocol selection means. Protocol notification means for notifying the communicating mobile terminal device of a wireless data communication protocol and causing the mobile terminal device to execute a reconnection procedure for switching to mobile data communication according to the notified alternative wireless data communication protocol. A base station apparatus characterized in that: 9. A connection between the mobile terminal device and the data communication device through a wireless network and a connection between the mobile terminal device and the data communication device through a communication network. A base station device that relays data communication performed in accordance with a protocol selected from a plurality of wireless data communication protocols, monitors the free space of a wireless channel during mobile data communication with a mobile terminal device, and monitors the monitoring result. Determining means for determining whether or not the wireless channel capacity for the mobile data communication during communication can be increased, based on the plurality of wireless data communications. Protocol selection means for selecting a wireless data communication protocol having a higher transmission capacity than the wireless data communication protocol in use from among the protocols, Notifying the mobile terminal device in communication of the wireless data communication protocol selected by the protocol selecting means, and causing the mobile terminal device to execute a reconnection procedure for switching to mobile data communication according to the notified wireless data communication protocol. A base station device comprising: a protocol notifying unit. 10. A connection is established between at least one base station device forming a wireless area via a wireless channel, and a connection is established between the base station device and a data communication device connected via a communication network, In a mobile terminal device performing data communication using a protocol selected from a plurality of wireless data communication protocols, a wireless data communication requesting or in use from said base station device during a request for mobile data communication or after starting communication. A reconnection control means for executing a reconnection procedure for switching to mobile data communication according to the notified wireless data communication protocol when a wireless data communication protocol different from the notified protocol is notified. Terminal device.