JPH11113066A - Data communication method, portable data communication equipment and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the data communication system in which a data storage form is dynamically alterable independently of restriction of a resource or the like at a terminal equipment side. SOLUTION: A client 10 is provided with a communication control section 11, a data processing section 12, a radio wave monitor section 13, and a data input output section 14, and with a memory 15 at the inside or outside of the client 10 and an external storage device 16. The data processing section 12 selects whether object data are stored in the memory 15 or in the memory 15 and the external storage device 16 altogether based on a comparison result between the capacity of object data and the capacity of the memory 15. Furthermore, the processing section 12 decides whether or not buffering processing is to be conducted, based on a radio wave state, a packet error rate and information relating to a response time or the like. Then based on the decision, the transmission object data are sent to an object server in a prescribed block unit via the communication section 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile computing environment, that is, a mobile terminal having a limited memory capacity, and an efficient and low-speed network for performing efficient data communication with a partner device in a computing environment. The method to be performed.

[0002]

2. Description of the Related Art For a public network such as the Internet or a network in an office constructed by a wired network,
Portable computers and PDAs (Personal Digital A
There is a data communication mode in which a portable mobile terminal represented by a ssistant is used to make a network connection from a remote place (hereinafter, remote access) and use resources in an office network environment. Remote access is
For example, a modem is attached to a mobile terminal, and a cellular phone network or PHS (Personal Handy Phone S) is connected through the modem.
It is performed by connecting to a mobile communication network such as a network (hereinafter, a PHS network).

[0003] Further, when data communication is performed by connecting to a wired network via a mobile communication network, a remote access server that executes processing related to remote access is provided on the wired network side, and the remote access server is connected to the remote access server. Generally, communication connection processing is performed. In this case, a communication environment is realized between the remote access server and the mobile terminal via a dedicated communication protocol. PPP (Point to Point Protoco
l) and SLIP (Serial Line Internet Protocol) are known as typical communication protocols.

[0004] By the way, when remote access is performed from a mobile terminal to a remote access server, problems inherent in mobile communication, that is, low communication speed, communication quality due to the presence of a blind zone of communication, and the like. There is a problem of low cost and high operation cost. Therefore, conventionally, software (hereinafter, mobile communication middleware) positioned as middleware for overcoming these problems has been developed. The mobile communication middleware performs, for example, buffering processing of transmission target data. That is, at the time of data transmission, transmission target data is stored in a memory area in the mobile terminal or an external storage device, and is read out at the time of transmission to perform necessary processing. This buffering process is also called data storage and exchange process.

[0005]

The above-mentioned conventional mobile communication middleware has the following problems. (1) In the case of mobile communication middleware that always stores transmission target data in an external storage device, the storage process always occurs, and thus a processing time delay occurs. (2) In the case of mobile communication middleware that always stores transmission target data in on-memory (only internal memory), since all transmission target data is processed in the memory area, the data processing content is the resource of the mobile terminal. Is limited to content that depends on (3) The mobile communication middleware is provided with a mechanism for ensuring data communication even in a poor communication state for the purpose of improving reliability. However, even in a good communication state, the same as in a bad state. Is performed, the load during data communication increases.

Such a problem commonly occurs in a data communication system in an environment in which data is stored and exchanged between a mobile terminal and various servers on a wired network side.

It is an object of the present invention to provide an improved data communication method capable of dynamically changing a data storage mode according to the size of data to be transmitted and a communication state. Another object of the present invention is to provide a portable data communication device suitable for carrying out the data communication method and a recording medium for causing a general-purpose computer device to function as the portable data communication device.

[0008]

A data communication method according to the present invention for solving the above-mentioned problems comprises connecting a portable data communication device having at least one data storage area to a destination device via a mobile communication network. Each time the portable data communication device transmits the transmission target data to the transmission destination device, the portable data communication device monitors a response status corresponding to the transmission, and based on the monitoring result, stores the subsequent transmission target data in the data storage area. After that, it is characterized in that it is dynamically determined whether to read and transmit at any time or to directly transmit. The response status at this time is a value obtained by quantifying the line state of the mobile communication network, an error rate during communication in the destination device,
And response time from the destination device.

Further, a portable data communication apparatus according to the present invention for solving the above-mentioned other problems provides both a transmission destination apparatus having means for returning response information to received data via a mobile communication network. Monitoring means for transmitting data to be transmitted to the destination apparatus and monitoring a response status thereof, and monitoring the response result by the monitoring means. On the basis of,
And a data processing means for determining whether to transmit and subsequently read the subsequent transmission target data in the data storage area as needed, or to directly transmit without storing the data in the data storage area.

This portable data communication device can be used as a mobile terminal, and the monitoring means is constituted, for example, as follows. (1) Information on the line state of the mobile communication network at the time of transmitting the transmission target data is acquired, and the acquired line state interferes with the transmission of subsequent transmission target data (a state in which data transmission is difficult, or The first signal is generated when transmission is unstable), and the second signal is generated when no trouble occurs. (2) While maintaining the transmission history of the transmission target data already transmitted, the difference between the scheduled transmission time of the subsequent transmission target data and the transmission time of the transmission target data transmitted immediately before is calculated, and the difference is determined as a predetermined value. A first signal is generated when the time is longer than the set time, and a second signal is generated when the time is shorter than the set time. (3) An error rate during communication for each data to be transmitted is obtained from the destination device and compared with a predetermined error reference value.
If the signal does not satisfy the error reference value, a second signal is generated.

In this case, when the data processing means receives the first signal from the monitoring means, the data processing means reads out the subsequent transmission target data in the data storage area as needed and transmits the data to the transmission destination device. Each time it is deleted from the data storage area. When the data storage area is composed of a plurality of areas, and the transmission target data is held in at least one of the data storage areas, the data processing unit determines the size of the transmission target data and each of the data storage area. It is configured to compare the capacity of the area and dynamically determine whether to use a single area or to use a plurality of areas in accordance with the result of the comparison. When a plurality of areas are used together, the area required for holding and reading out the area is the shortest, for example, the subsequent transmission target data is preferentially held in the internal memory of the apparatus itself, and the remaining data is
The data is stored in another area, for example, a storage area of an external storage device.

According to another aspect of the present invention, there is provided a recording medium capable of two-way communication via a mobile communication network to a destination device having means for returning response information to received data. Is connected to, and read by a computer device having at least one data storage area, a recording medium recording a program that causes the computer device to function as a mobile data communication device, wherein the program performs at least the following processing The program is executed by the computer device. (1) a process of transmitting data to be transmitted to the destination device and monitoring a response status thereof, and (2) as needed, after storing subsequent data to be transmitted in the data storage area based on a result of the monitoring process. A process of determining whether to read and transmit or to directly transmit without holding the data in the data storage area; (3) when storing the transmission target data in the data storage area, A process of determining which data storage area is to be preferentially held; (4) each time the held transmission target data is read out from the data storage area and delivered to the transmission destination device, the transmission target Deleting data from the data storage area; This program desirably causes the computer device to execute each of the processes as middleware.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. (First Embodiment) FIG. 1 is a functional block diagram showing an embodiment in which the present invention is applied to a data communication system constructed via a public network such as the Internet, a digital cellular network for mobile phones, a PHS network or the like. FIG.

The data communication system 1 receives a remote access from a client 10 which is a mobile terminal (portable data communication device) having a wireless terminal and a plurality of servers functioning as transmission destination devices, ie, the client 10. High-efficiency communication server 3 that performs communication processing for remote access server 20 and client 10
0, a plurality of service servers 40 for providing applications and information are connected and arranged to enable two-way communication via a public network L1, a PHS network L2, and a digital cellular network L3. In the following description, the PHS network L
2 and the digital cellular network L3 together with the mobile communication network L
Called R.

The service server 40 has applications and information unique to the present system, and includes, for example, a database system for performing a database search process. In FIG. 1, the remote access server 20, the high-efficiency communication server 30, and the service server 40 are configured in a separated and independent form. However, the present invention is not limited to such a form. May be configured together.

The client 10 includes a communication control unit 11, a data processing unit 12, a radio wave monitoring unit 13, a data input / output unit 14 formed by reading and executing a memory 15, an external storage device 16, and a predetermined program. It is provided with the respective functional blocks. In relation to the components of the present invention, the memory 15 and the external storage device 16 are data storage areas, the communication control unit 11 and the radio wave monitoring unit 13 are monitoring units,
The communication control unit 11 and the data processing unit 12 function as data processing means. A hard disk can be used as the external storage device 16.

The program is usually stored in an internal storage device or an external storage device other than the memory 15 and is read and executed as needed. For example, it may be stored in a computer-readable form on a CD-ROM, FD, or the like, and may be installed in the above-mentioned internal storage device or external storage device at the time of use and provided for execution at any time.

In the client 10, the communication control unit 1
Reference numeral 1 denotes data communication via the mobile communication network LR, and the data processing unit 12 performs processing and settings corresponding to the line state of the mobile communication network LR, in this example, the radio wave state. The radio wave monitoring unit 13 monitors a radio wave state of the mobile communication network LR per a predetermined unit time. The data input / output unit 14 is for inputting a data acquisition request from a user or the like via an input device (not shown) and presenting a result related to the data acquisition request via a display device or the like (not shown).

FIG. 2 is a conceptual diagram of the configuration of the data communication system 1. In the present embodiment, the high-efficiency communication server 30 is disposed on the mobile communication network LR or the public network L1, and conceptually has a function of mediating data communication between the client 10 and the service server 40. With. The “hardware” of the client 10 and the high-efficiency communication server 30 are parts determined depending on the computer device or the like to be used. Client 1
0 is a communication application, and is a “server AP” of the service server 40.
Is a server application operated by a plurality of service servers.

The “middleware” of the client 10 is:
The high-efficiency communication server 30 issues a data communication request to the high-efficiency communication server 30 based on the communication state, the data amount, the client-side resources, and the like. The data and the result obtained from the service server 40 are transmitted to the “middleware” of the corresponding client 10.

Next, the operation of the client 10 will be described. The client 10 performs data storage and exchange by double buffering processing using both the memory 15 and the external storage device 16. It is also assumed that the capacity of the memory 15 to be used for data exchange is set in advance.

FIG. 3 is an explanatory diagram of the procedure of the data storage and exchange process in the client 10. Here, for convenience,
In order to focus on the double buffering process, the process in the radio wave monitoring unit 13 is omitted. 3, when data to be transmitted is input to the data input / output unit 14 (Step S101: Yes), the data processing unit 12
It is determined whether the data amount is within the range that can be stored in the area of the memory 15. If it is within the range (Step S102: Ye
s) All of the transmission target data is stored in the memory area (step S105). On the other hand, if it exceeds the range (step S102: No), only the data of the storable capacity is stored in the area of the memory 15 (step S10).
3) The excess data is stored in the external storage device 16 (step S104). Then, the data processing unit 1
2 transfers the transmission target data to the client AP (step S106), and further divides the data into blocks of a predetermined size (step S107). At this time,
After transmission of one block, subsequent blocks can be specified continuously. The communication control unit 11 sequentially performs a transmission process in block units when the communication becomes possible (steps S108 to S110).

The reason why the processing is performed in units of blocks is to facilitate the restart of data communication from the time of occurrence of a failure when the failure occurs during data communication. Note that data transmission is performed by packets. In this case, the unit block corresponds to the packet size.

In the data communication system 1 of the present embodiment,
Every time the transmission target data transmitted in block units reaches the high-efficiency communication server 30, the data stored in the area of the memory 15 and the external storage device 16 on the client 10 side is deleted for each corresponding block. It is configured as follows. Therefore, if all the target data is received on the high-efficiency communication server 30 side, the corresponding data held in the area of the memory 15 and the external storage device 16 on the client 10 side is all erased. Become.

By the way, factors that become bottlenecks when performing data communication in a mobile computing environment,
For example, in the case of an inferior radio wave condition, efficient data communication can be realized by performing the data storage and exchange processing. However, in the case of a good radio wave condition, the data communication becomes more efficient if the data storage and exchange process is not performed. Therefore, in the present embodiment, the transmission target data is
0 is stored in the memory 15 and the external storage device 16,
Alternatively, it is determined whether the data is to be passed directly to the communication control unit 11 without being stored. The former is a buffering process, and the latter is a non-buffering process. Whether to perform the buffering process or the non-buffering process can be set, for example, as an initial system parameter. In the present embodiment, this is dynamically switched during system operation. The following factors can be considered as factors for performing the dynamic switching process.

(1) Radio wave condition (2) Error rate during packet communication (hereinafter, packet error rate) (3) Response (response) time The switching method corresponding to these factors is as follows: A description will be given by referring to a packet error rate monitoring method and a response time monitoring method.

<Radio wave condition monitoring method> This method is based on (1)
The data processing unit 12 acquires from the radio wave monitoring unit 13 information on the radio wave condition at the time of immediately preceding data communication, and holds the information. Then, when the transmission target data is input to the data processing unit 12, the held radio wave state is checked. When the radio wave condition is good, the setting of the buffering process is canceled, and the transmission target data is directly transmitted to the communication control unit 1.
1 to be transmitted. Whether the radio wave condition is good or bad is determined based on the degree of traffic congestion and / or the strength of the reception level. That is, when the traffic is congested or when the reception level is lower than the reference value, it can be determined that the state is defective.

FIG. 4 is a diagram showing a communication processing procedure in the radio wave condition monitoring system. The difference between the communication processing procedure here and the communication processing procedure of FIG.
02 relates to the processing of the radio wave monitoring unit 13. Therefore, this difference will be described. Data input / output unit 1
4, when the transmission target data is input to the data processing unit 12, the radio wave monitoring unit 13 checks the radio wave state at the time of the current data communication (step S <b> 202). If the radio wave condition is poor, the fact is notified to the data processing unit 12 (step S202: No), and the above-mentioned steps S102 to S10 are performed.
6 (steps S203 to S20).
7). On the other hand, when it is determined that the radio wave condition is good (step S202: Yes), the above steps S102 to S10
6, the transmission target data is immediately divided (step S208), and the same processing as steps S108 to S110 is performed.

<Packet Error Rate Monitoring Method> This method focuses on the packet error rate of (2).
The packet error rate is expressed as a ratio of error packets to all transmission packets. The data processing unit 12 is configured to acquire and hold a packet error rate when data is transmitted and received from the communication control unit 11. When the packet error rate is high, the setting of the buffering process is performed, while when the packet error rate is low, the setting of the buffering process is canceled. If the transmission interval associated with the data transmission process is long and the transmission / reception process is not performed continuously, the held packet error rate may become invalid. In this case, the communication control unit 11 resets the packet error rate when setting the buffering process. Furthermore, in order to confirm the transmission interval, the transmission time after the transmission processing is held.

FIG. 5 shows an example of a processing procedure based on the packet error method. When the transmission target data is passed to the client AP (step S301), the communication control unit 11 determines the lapse of time accompanying the transmission processing. Specifically, a difference between the current time and the previous transmission time is obtained, and when the difference is equal to or longer than a predetermined reference time (step S302: large), the communication control unit 11 resets the current packet error rate (step S302). Step S303). On the other hand, when the difference is less than the reference time (step S302: small), the communication control unit 1
1 acquires a new packet error rate (step S3).
04), the packet error rate is determined. When the packet error rate is larger than the predetermined reference value (step S305: high), the setting of the buffering process is turned on (step S306). Thereby, the buffering process is set. When the buffering process is on, the processes of steps S102 to S105 described above are performed. If the packet error rate is less than the reference value (step S305: low), the buffering process is turned off (step S307). Thereby, the buffering process is canceled. After a series of processes is completed, the communication control unit 11 performs a transmission process according to the setting status of the buffering process (step S308). After this transmission, the transmission time information is stored (step S
309).

<Response time monitoring method> This method focuses on the response time of (3), and a delivery confirmation accompanying the packet transmission arrives after the communication control unit 11 transmits a specific packet. The measurement is performed using the time average up to the response time as the response time. This method can be realized by the same processing procedure as the packet error rate monitoring method shown in FIG. That is, the response time may be obtained as an alternative to the packet error rate. The packet delivery confirmation is performed between the middleware in the client 10 and the high-efficiency communication server 30.

For the radio wave condition and the packet error rate, for example, in a PHS network, a PIAF (PHS
It can be obtained from the telephone based on a data communication protocol compatible with the public network such as rnet Access Forum Standard). On the other hand, the response time can be configured to be confirmed by middleware between the client and the server when data is obtained from the application after connecting to the server.

As for the switching method between the above three types of buffering processing / non-buffering processing, any one of them may be selected or a method of use may be determined as necessary such as mutual use. For example, in the case of mutual use, a radio wave condition monitoring method is adopted as a basic buffering process setting. However, if the packet error rate is high despite good radio wave conditions, buffering is performed. Set to perform ring processing. Or, if the packet error rate is low but the response time is long,
It can be configured in an appropriate combination, such as setting to perform buffering processing.

As described above, in the data communication system 1 of the present embodiment, since the buffering process and the non-buffering process can be dynamically changed in the client 10, the data communication system 1 depends on hardware resources as in the conventional system. It is possible to select an optimal buffering process without being limited to the data processing performed.

Further, it is possible to avoid a delay in processing time caused by always writing data in an external storage area as in the related art, and to shorten a communication time. Furthermore, since the setting of the buffering process is changed in response to an external factor such as a radio wave state, the same processing as in the case of a poor state is not performed even in a good communication state as in the related art. , And efficient processing becomes possible. As described above, according to the data communication system 1 of the present embodiment, it is possible to reduce the communication cost and load of the entire system.

(Second Embodiment) The present invention can also be implemented as a data communication device using a stand-alone computer device. As a configuration example of the data communication device in this case, a stand-alone computer device is used and provided with the same functional block group as the client 10 of the data communication system 1.

The difference between this data communication device and the client 10 is the functional blocks of the communication control unit 10 and the radio wave monitoring unit 13. The client 10 can be adapted to a mobile communication network such as mobile communication. However, in the data communication device, the communication control unit 1 can communicate with a wired network in addition to the wireless communication.
1 and the radio wave monitoring unit 13 can be replaced, and the same effect as that of the data communication system 1 can be obtained.

[0038]

As is clear from the above description, according to the present invention, data is not limited to the resources of the target terminal, but can correspond to external factors such as data traffic and radio wave conditions. The storage method can be dynamically changed, and the processing efficiency related to data communication is significantly improved.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a data communication system according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram of a software configuration in the data communication system 1.

FIG. 3 is a processing procedure diagram in a double buffer system.

FIG. 4 is a processing procedure diagram in the radio wave condition monitoring method.

FIG. 5 is a processing procedure diagram in the packet error rate monitoring method.

[Explanation of symbols]

 Reference Signs List 1 data communication system 10 client 11 communication control unit 12 data processing unit 13 radio wave monitoring unit 14 data input / output unit 15 memory 16 external storage device 20 remote access server 30 high efficiency communication server 40 service server L1 public network L2 PHS network L3 digital cellular network

Claims (13)

[Claims] 1. A portable data communication device having at least one data storage area and a destination device are connected via a mobile communication network, and the portable data communication device transmits data to be transmitted to the destination device. Each time is transmitted, the response status corresponding to the transmission is monitored, and based on the monitoring result, the subsequent transmission target data is read out at any time after being held in the data storage area and transmitted or transmitted directly. A data communication method characterized by dynamically determining 2. The response status is information including any one of a value quantifying a line state of the mobile communication network, an error rate during communication in the destination device, and a response time from the destination device. The data communication method according to claim 1, wherein: 3. An apparatus which is connected to a destination apparatus having means for returning response information to received data so as to be capable of two-way communication via a mobile communication network and has at least one data storage area. Monitoring means for transmitting transmission target data to the transmission destination device and monitoring a response status thereof, based on a result of monitoring by the monitoring means, after storing subsequent transmission target data in the data storage area A data processing unit for determining whether to read and transmit at any time or to directly transmit without holding the data in the data storage area. 4. The monitoring means acquires line state information of the mobile communication network when transmitting transmission target data,
The first signal is generated when the acquired line state interferes with the transmission of the subsequent data to be transmitted, and the second signal is generated when the acquired line state does not interfere. The data processing unit is configured to output the first signal from the monitoring unit. 4. The portable data communication device according to claim 3, wherein when the first signal is received, the subsequent transmission target data is read out at any time after being held in the data storage area. 5. The monitoring means retains a transmission history of already transmitted transmission target data, and calculates a difference between a scheduled transmission time of a subsequent transmission target data and a transmission time of the transmission target data transmitted immediately before. When the difference is equal to or longer than a predetermined time, the first signal is generated, and when the difference is less than the predetermined time, the second signal is generated. The data processing unit outputs the first signal from the monitoring unit. 4. The portable data communication device according to claim 3, wherein when receiving the data, the subsequent data to be transmitted is stored in the data storage area and then read at any time. 6. The monitoring unit obtains an error rate during communication for each transmission target data from the transmission destination device and compares the error rate with a predetermined error reference value, and when the comparison result is equal to or larger than the error reference value. Is configured to generate a first signal and a second signal if the error reference value is not satisfied. The data processing means, when receiving the first signal from the monitoring means, 4. The portable data communication apparatus according to claim 3, wherein the portable data communication apparatus is configured to read data as needed after holding the data in the data storage area. 7. When the data storage area is composed of a plurality of areas, and the data to be transmitted is held in at least one of the data storage areas, the data processing means determines the size of the data to be transmitted and the data size. It is configured to compare the capacity of each area of the storage area and dynamically determine whether to use a single area or to use a plurality of areas in accordance with the comparison result. The portable data communication device according to claim 3. 8. When a plurality of areas are used in combination, the data processing means preferentially holds the subsequent data to be transmitted in an area where the time required for holding and reading the data is the shortest, and stores the remaining data in another area. The portable data communication device according to claim 7, wherein the portable data communication device is configured to be held in an area. 9. The portable data communication device according to claim 8, wherein the first area is formed in an internal memory of the own device, and the second area is formed in a storage area of an external storage device. . 10. The data processing means erases the transmission target data from the corresponding area of the data storage area each time the transmission target data is read from the data storage area and delivered to the transmission destination device. 9. The portable data communication device according to claim 7, wherein the portable data communication device is configured as follows. 11. The data processing means is configured to divide the data to be transmitted into a plurality of blocks, and to be able to successively specify a subsequent block after transmitting one block. Item 11. The portable data communication device according to any one of Items 3 to 10. 12. A computer having at least one data storage area, connected to a destination device having means for returning response information to received data so as to be capable of two-way communication via a mobile communication network. A recording medium that is read by a device and records a program that causes the computer device to function as a mobile data communication device, wherein the program transmits at least data to be transmitted to the destination device and monitors a response status thereof. Based on the result of the monitoring process, whether the subsequent transmission target data is to be read and transmitted at any time after being held in the data storage area, or whether to directly transmit without holding the data in the data storage area A process of determining, when storing the transmission target data in the data storage area, A process of deciding whether or not the data to be stored in the data storage area is preferentially stored. Each time the stored data to be transmitted is read from the data storage area and delivered to the destination device, the data to be transmitted is stored in the data storage area. A recording medium characterized by causing the computer device to execute a process of erasing from an area. 13. The recording medium according to claim 12, wherein the program causes the computer device to execute each of the processes as middleware.