JPH0918483A - Radio communication network system - Google Patents

Abstract

PURPOSE: To improve the reliability of a network and the communication efficiency of the whole of the network by properly judging the service providing status of a server and the status of the communication route to the server and suppressing the generation of wasteful traffic. CONSTITUTION: A BCD reception processing part 31 receives the broadcast communication data (BCD) transmitted from a server by a prescribed time interval via an antenna 6. The service providing status on a server side which is contained in the BCD is stored in a server information table 32. Further, when the service request is received from an operator, a client AP 30 refers to this server information table 32. When the server judges the status as the one in which the processing of service is impossible within prescribed response time, the transmission of the service request to the server is not performed. By this constitution, the reliability of the network and the communication efficiency of the whole of the network are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network system such as a LAN, and in particular, a personal computer or a POS terminal having a wireless communication function is used as a client, and wireless communication is performed directly with these clients. The present invention relates to a server / client type wireless communication network system which provides a database service and a transaction processing service such as customer information inquiry as an application service by using a workable workstation or office computer as a server.

[0002]

2. Description of the Related Art In recent years, personal computers and POS
Local area network (LA
N) Systems are becoming widely used. In particular, in addition to the conventional wired LAN system, recently, a wireless communication LAN system using wireless communication is becoming widespread.

FIG. 25 shows a general processing procedure on the client side in a conventional wireless LAN system. A client included in a conventional wireless LAN system receives a service request from an operator (step 201,
Hereinafter, abbreviated as S201), the service request data is transmitted to the server (S202), and the response data to the request is waited (S203). If the server is operating normally and there is no malfunction such as radio interference on the wireless communication path, the service request data sent by the client is received normally on the server side, and the result of the request is returned to the client as a response. Side is notified (S2
04).

However, when the server is not in operation, when the service request data on the client side does not reach the server due to a failure during communication, or the service result (response) on the server side to the service request is sent to the client. If it does not arrive, the client side will not receive a normal response, and the client side will send the same service request data again after a predetermined time has elapsed (after a timeout) (S205). That is, the data is retransmitted (S207). When no response is obtained again for data retransmission (S206)
Notifies the operator of a no-response error indicating that there was no response to the transmitted service request data (S208).

In the conventional LAN system, the transmission / reception confirmation between the server / client can be performed by the above procedure.

[0006]

As described above, in the conventional LAN system, regardless of whether it is a wired system or a wireless system, when a service request is issued from the operator on the client side, the client side operates on the server. The service request data was transmitted to the server according to the instruction from the operator regardless of the operating status of the server. In order for this service request to be processed correctly and an appropriate service result to be returned, (1) the server is running, and (2) the load on the server side responds to the new service request within a proper time. Must be small enough to return, and (3) the transmission / reception data can be correctly transmitted / received without any failure in the wireless / wired communication medium, and three conditions must be satisfied.

In the case of a general LAN system, the operating status of the server can usually be ascertained based on a predetermined schedule. However, in practice, the server may fall into an operation stop state due to a cause that is difficult to predict in advance, such as a hardware failure, and it becomes impossible to respond to the service request. In order to improve the reliability of the network system, it is necessary to detect such a failure as soon as possible and appropriately.

However, from the viewpoint of detecting a communication failure, the wireless communication LAN system has a unique problem due to external noise that the wired communication LAN system does not have. In the case of a wired communication system, the noise resistance characteristic is uniquely determined by the characteristic of the cable used. In other words, once the installation adjustment work is performed at the time of constructing the system and the adjustment is properly performed, the fluctuation of the situation of the communication medium during the system operation is much smaller than that of the wireless system. Further, if any abnormality occurs in the communication cable, it affects all the terminals connected to the cable, so that it is relatively easy to detect the communication failure.

On the other hand, in the case of a wireless communication system,
Electromagnetic waves centered on a specific frequency are used as a communication medium, and the condition of space within a certain range determined by the transmission output affects communication. In the case of wireless communication, the antennas are completely open, and the obstacles and reflectors between the antennas have a large effect on the communication, and the communication status also changes significantly when a moving object crosses the antennas. There are cases. In addition, the communication status may change depending on the day or the time of day. Further, in the case of a wireless communication system, unlike the case of wired communication, even if communication with a certain terminal cannot be performed, communication with another terminal can be normally performed. Therefore, even though a certain client was communicating normally with the server at a certain time, it suddenly became unable to communicate at the next moment, and after a certain period of time, normal communication would be possible again. Things can happen.

That is, in the case of a wireless communication system, if a communication error occurs between a server and a client, it may be a temporary communication failure due to a temporary failure on the communication path, or the server side It is difficult to judge whether there is a serious communication failure due to operation stop, etc., and system reliability deteriorates if it is wrongly decided whether it should be left alone or if recovery work should be started immediately. There is a problem in that it may be caused.

Further, normally, a system is configured such that one server receives service requests from a plurality of clients and returns the results of processing different service requests. Therefore, when service requests from multiple clients are concentrated in a short period of time, a large load is placed on the server to process the requests, and new service requests are processed within an appropriate response time. May not be able to
There is a problem that the processing efficiency of the entire network is deteriorated.

The present invention has been made in view of the above-mentioned problems, and in a wireless communication network system, when a communication failure occurs in the network, this failure may be transient due to an obstacle or the like on the wireless communication path. Therefore, it is possible to appropriately determine whether the communication is serious due to a malfunction of the terminal or the like, and to prevent deterioration of communication efficiency of the network due to communication failure, overload on the server side, or the like.

[0013]

In order to solve the above problems, a wireless communication network system according to claim 1 of the present invention is a wireless communication network system for performing data communication between a server and a client by wireless communication. In the above, the server creates broadcast data including information indicating whether or not it is possible to provide a service within a predetermined response time in response to a service request from the client, and the client creates the broadcast data at a predetermined transmission time interval. In addition to the broadcast data transmitting means for transmitting to the server, the communication control means provided in the client for transmitting a service request to the server is configured so that the broadcast data transmitted from the server has passed a predetermined reception time interval. Service does not arrive, or the service cannot be provided within the specified response time in the received broadcast data. If contains information indicating that is characterized by not transmitting the service request to the server.

In order to solve the above-mentioned problems, a wireless communication network system according to claim 2 of the present invention comprises:
In a wireless communication network system that performs data communication by wireless communication between a server and a client, the server creates broadcast data including server operation information indicating the operation status of the server and sends it to the client at predetermined time intervals. And a server information holding unit for holding server operation information included in the broadcast data every time the client receives the broadcast data from the server, and a broadcast data transmitted from the server. An information requesting unit that creates server information request data including an inquiry about the operating status of the server and sends it to another client when the data does not arrive even after a predetermined reception time interval, and a server information request from another client. When the data is received, the server operation information stored in the server information storage means is included. Create a server information response data is characterized by and a response means for transmitting to said client.

According to a third aspect of the present invention, in the wireless communication network system according to the second aspect, when the client receives the server information request data, the identifier of the client from which the server information request data is transmitted. Further comprising notifying means for creating notification data including the above and transmitting the notification data to the server, and when the transmitting / receiving means provided in the server for transmitting / receiving data to / from the client receives the notification data. The transmission of data is stopped to the client having the identifier included in the notification data.

[0016]

According to the structure described in claim 1, the broadcast data transmitting means provided in the server transmits the broadcast data to the client at a predetermined transmission time interval so that the server operates normally. The client side can detect whether or not the communication path between the server and the client is in a normal state. In other words, if the broadcast data does not arrive at the client even after a predetermined reception time interval has passed, either some abnormality has occurred in the server and transmission of the broadcast data has become impossible, or the server and client have This is the case where some kind of failure occurs in the communication path between them. This makes it possible for the client side to appropriately detect whether or not communication with the server can be normally executed.

Further, since the broadcast data includes information indicating whether or not the server can provide the service within a predetermined response time to the service request, for example, the service request is concentrated. If the server becomes overloaded, the client will know that the server is in a state where it cannot process the next new service request. In addition, the communication control means provided in the client can provide the service within a predetermined response time in the received broadcast data if the broadcast data does not arrive even after the predetermined reception time interval elapses. If it is determined that the service request from the client will reach the server without fail by not sending the next service request when the information indicating that it is impossible is included. Since the service request is transmitted only to the network, unnecessary communication traffic is prevented from occurring in the entire network, and the communication efficiency can be improved.

According to the second aspect of the present invention, the broadcast data transmitting means provided in the server transmits the broadcast data to the client at a predetermined time interval so that whether the server is operating or not can be checked. The side can detect. Further, this broadcast data includes server operation information indicating the operation status of the server, and the client receiving the broadcast data holds the server operation information in the server information holding means. Since the server information holding means holds the server operation information every time the broadcast data is received, the latest server operation information is always held on the client side. Further, if the broadcast data from the server does not arrive at a certain client even after a predetermined reception time interval, the information requesting means transmits the server information request data for inquiring the operating status of the server to another client, The client receiving the server information request data sets the latest server operation information held by itself in the server information response data and returns it. With this, when a communication error with the server occurs, the client uses information obtained from other clients to determine whether the cause of the error is in the server itself or in the communication path with the server. It becomes possible to confirm. As a result, if there is a communication error due to an error in the server itself, for example, by issuing an instruction to start recovery work immediately, it is possible to quickly recover from a network failure and prevent deterioration of system reliability. be able to. Further, for example, if the server information request data is transmitted to a plurality of clients and the server information response data from all of these clients is comprehensively judged to detect the server operation status, the server operation status Can be confirmed more reliably.

According to the third aspect of the invention, when a client inquires about the operating status of the server from another client, the notifying means provided in the client that has received the inquiry is the identifier of the client of the inquiry source. Is notified to the server. As a result, the server can know the client in which a communication error has occurred with itself, and further, the transmitting / receiving means provided in the server prevents the client from transmitting data to the client. This prevents wasteful transmission such as data resending to a client that is unlikely to reach the transmission data due to communication failure, and as a result suppresses the generation of useless communication traffic in the entire network. The communication efficiency can be improved.

[0020]

【Example】

Embodiment 1 FIGS. 1 to 1 show an embodiment of the present invention.
1 will be described below. In the wireless communication network system according to the present embodiment, a plurality of clients wirelessly send a service request to one server, the server performs a service process according to the service request, and displays the result of the service process. It is designed to be sent to the client that sent the service request. In the following, for convenience of explanation, as shown in FIG. 3, and one of the server 1, the client ₁ 2 n units, the client ₂ 3, ...
A network system configured with the client _n 4 will be described as an example, but it goes without saying that the number of servers on the network system is not limited to one and may be two or more.

As shown in the figure, the server 1 and the client ₁ 2, client ₂ 3, ... and each of the client _n 4, provided with respective antennas 5, 6, 7 and 8, via these antennas Between the server 1 and each client, service request data, response data, or broadcast data (BC: Broadcast Commun) described later.
(ication) etc. are transmitted and received.

Next, the configuration of the server 1 will be described.
Server 1, as shown in FIG. 2, an application program for providing a service to the service request from each client (hereinafter abbreviated as AP) server AP ₁ 10 is, the server AP ₂ 11, ... server AP _k
12, a service information table 13 that stores information on the service provision status of these server APs, and a usage status of various hardware resources (not shown) in the server 1 (C
(PU load rate, disk usage, memory usage, etc.)
A monitoring process 14 for monitoring data, a transmission process 15 (broadcast data transmission means) for creating and transmitting broadcast data, which will be described later, and a data transmission / reception processing unit configured by hardware and software to control transmission / reception of data. 16 and 16.

The above service information table 13
Stores, for all the server APs included in the server 1, a unique identifier given to each server AP and a service providing flag indicating whether or not the service of each server AP is currently provided, in association with each other. Is. FIG. 4 is an explanatory diagram showing the configuration of the service information table 13. As shown in FIG. 4, the service information table 13 stores an identifier field 13a in which the identifier of the server AP is stored and a service provision flag. The flag field 13b and the identifier field 13a and the flag field 13b are provided corresponding to all the server APs included in the server 1.

[0024] In addition, the above-mentioned server AP ₁ 10~AP _{k 1}
2 of each of the analysis and of the service request data transmitted from the client, the communication processing unit ₁ 10a in order to perform the assembly and the like of the response data to the client, the communication processing unit
₂ 11a, ... Includes a communication processing unit _k 12a.

Next, the above-described server AP ₁ 10, the monitoring process 14, and the procedure of processing the transmission process 15 is carried out as follows to respectively described.

Firstly, with reference to FIG. 5, the operation of the server AP ₁ 10. A plurality of AP as described above is on the server 1 (server AP ₁ 10～AP _k 1
2) operate, but they to almost the same operation, will be described here as an example the operation of the server AP ₁ 10. After booting, the server AP 110 _first performs service start processing such as initial setting, and at the end of this processing, sets its own service provision flag to O in the service information table 13.
Set to N (service being provided) (S1). In particular, the server AP ₁ 10 searches its own identifier in the identifier field 13a of the service information table 13, and sets the service providing flags in the flag field 13b corresponding to the identifier to ON. After that, the presence or absence of a service request from the client is checked (S2), and if there is a service request, the service is provided according to the request (service processing).
Is performed (S3).

At this time, in parallel with the execution of the above service processing, it is confirmed whether or not the processing can be performed within an appropriate predetermined response time when the next service request is generated (S4). ), If it is determined that the processing cannot be performed within the appropriate response time (NO in S4)
Sets its own service provision flag in the service information table 13 to OFF (service is stopped) (S5), and returns to S4 again.

Further, in S4, when it is determined that the service processing up to immediately before is completed, and it becomes possible to respond to the next service request within an appropriate response time (S4).
In YES, the service provision flag of the service information table 13 is turned ON (S6 / S7), and the next service request is accepted. This is repeated until the service end time (S8), and when the service end time comes, the service providing flag of the service information table 13 is turned off and the process ends (S9).

Next, the operation of the monitoring process 14 will be described with reference to FIG. The monitoring process 14 acquires system resource information (CPU load rate, disk usage amount, memory usage amount, etc.) after startup (S11), and determines whether the system resource usage rate exceeds a predetermined level. If it is confirmed (S12), if it exceeds the limit, the entire contents of the service information table 13 are saved / stored in the save area (S13), and all the service provision flags of the service information table 13 are turned off (S14).

On the other hand, if the utilization rate of the system resources does not exceed the predetermined level in S12, it is confirmed whether there is any data saved immediately before in the save area (S15). For example, the contents are returned to the service information table 13 as they are (S16), and the process returns to S11 to perform the resource information acquisition processing.

[0031] As described above, the server AP ₁ 10 determines whether it is possible to respond in the appropriate time for the next service request in accordance with its processing capacity, the service information according to the result of this determination ON / OFF operation of only the service provision flag of itself in the table 13
As described above, the monitoring process 14 collectively operates all the contents of the service information table 13 while monitoring the usage rate of the entire system resources of the server 1.

In this way, the monitoring process 14 monitors the system resources of the server, and when the usage rate of the system resources exceeds a predetermined level, the service information table 13
By setting all the service providing flags of 1 to OFF so as not to accept a new service request, it is possible to prevent the service request from being abnormally processed due to the overloaded state of the server for a long time. As a result, it becomes possible to improve the service efficiency of the entire network system. In addition, when the utilization rate of the system resources immediately returns to a predetermined level or less, as described above, if there is data saved in the save area immediately before, this data is changed to the service information table 13 The previous information about the status of the system can be reused by returning to.

Next, the operation of the transmission process 15 as the broadcast data transmitting means described in claim 1 will be described with reference to FIG. Send process 1
After starting, the device 5 first resets the transmission timer 17 shown in FIG. 2 and then starts counting (S21). Next, the transmission process 15 checks whether or not the count value of the transmission timer 17 has exceeded a predetermined transmission time interval t1 (S22). If this count value exceeds the transmission time interval t1, the service information table 1
By reading the service provision flag of No. 3, information regarding the service provision status of all the server APs of the server 1 is acquired (S23), and the acquired information is set in the broadcast data and transmitted (S24). Above S21-S2
The process 4 is repeatedly executed while the server 1 is operating.

Here, the broadcast data created by the transmission process 15 will be described. FIG. 8 is an explanatory diagram showing an example of the format of broadcast data. As shown in the figure, the broadcast data includes a header section 20 and an information section 2.
And 1.

The header section 20 is a section that depends on the communication protocol, and its format is determined by the communication protocol used by the wireless communication network system of this embodiment. The information part 21 is a part set in the transmission process 15 based on the contents of the service information table 13 as described above. The head portion of the information section 21 is a server identification number section 22 in which the identification number of the server is set. Further, following the server identification number part 22, a service information part 23..23 including an AP identifier field 23a in which the identifier of one server AP is set and a flag field 23b in which the service provision flag of the AP is set. But all A that server 1 has
It is sequentially set corresponding to P.

In the configuration of this embodiment, the server identification number part 2
The 2 are set "SVID1" is the identification number of the server 1, the first service information part 23, an identifier of the server AP ₁ 10 to the identifier field 23a "SID
1 "is set, the flag field 23b serving flag of the server AP ₁ 10 may, for example, indicating that the service providing" as 1 "or indicating that the outage" 0 ", read from the service information table 13 After that, the server AP is set in the same manner as above.
_The service information section 23 in which the identifiers and service provision flags for each application program up to _k 12 are set follows.

As described above, the broadcast data created by the transmission process 15 based on the contents of the service information table 13 is transmitted from the server 1 to each client at a predetermined transmission time interval t1, whereby each client is , The service provision status of all the server APs of the server 1 can be confirmed.

Next, the configuration and operation on the client side will be described. Wireless communication network system includes a plurality of clients of the embodiment (the client ₁ 2, client ₂ 3, ... client _n 4) is provided with the, for each client a substantially similar structure, where the client ₁ 2 only explain.

As shown in FIG. 1, the client ₁₂ is
A client AP 30, a broadcast data reception processing unit 31 for receiving broadcast data transmitted from the server 1,
A server information table 3 in which information on the service provision status of the server 1 is stored based on the received broadcast data and the like.
2, a reception monitoring timer 33 for measuring a reception time interval of broadcast data, and a data transmission / reception unit 3 configured by hardware and software for controlling transmission / reception of data.
4 is provided.

Further, the client AP 30 includes a communication processing unit 30a for assembling service request data and analyzing response data, and accepts service requests from operators who use the services and responds to the service requests to the operators. Notification of.

The server information table 32 is stored in the broadcast data reception processing unit 3 according to the information contained in the broadcast data.
It is updated by 1 and referred to by the client AP 30. In addition, the reception monitoring timer 33 is reset by the broadcast data reception processing unit 31 and starts a new count each time the broadcast data is received.

Here, an example of the configuration of the server information table 32 will be described in detail with reference to FIG. As shown in FIG. 9, the server information table 32 includes a server identification number section 41 in which the identification number of the server is stored, and an operation flag section in which a flag indicating the operating status of the server, that is, whether or not the server is operating is stored. 42 and a service information section 43, 43 ... In which information about the service provision status of each server AP is stored. It should be noted that this record 40 is provided in the same number as the number of servers on the network, and one for each server.
The server identification number section 41 is provided to handle the above. It should be noted that the service information section 43 is the server AP.
Server AP identifier field 43 storing the identifier of
a and a flag field 43b in which the service providing flag of the server AP is stored.

Upon receiving the broadcast data from the server 1, the broadcast data reception processing section 31 sets the contents of the server identification number section 22 in the information section 21 of the broadcast data in the server identification number section 41 of the server information table 32. To do. Similarly,
From the service information section 23, 23 ... In the information section 21 of the received broadcast data, the identifier of the server AP and each server A
The service provision flag of P is taken out, and the AP identifier field 43 of the service information section of the server information table 32 is extracted.
a and the flag field 43b, respectively. In this way, every time the broadcast data is received, the contents of the server information table 32 are updated by the processing of the broadcast data reception processing unit 31 based on the received broadcast data.

Next, the procedure of the processing performed by the broadcast data reception processing section 31 and the client AP 30 will be described below.

As shown in FIG. 10, the broadcast data reception processing section 31 initializes all contents of the server information table 32, that is, the flag of the operation flag section 42 and the flag field 43b of the service information section 43 as an initial setting. O
It is set to FF, and the reception monitoring timer 33 is reset while the server is not in operation and the service is stopped, and the reception monitoring timer 33 is reset (S31). Next, it is checked whether or not the broadcast data is received (S32), and when the broadcast data is received, the reception monitoring timer 33 is reset (S33), and according to the contents of the information section 23 of the received broadcast data, the above-mentioned is performed. like,
The contents of the server information table 32 are updated (S34).

When the broadcast data is not received (NO in S32) and the count value of the reception monitoring timer 33 exceeds the predetermined reception time interval t2 (YES in S35), the broadcast data is broadcast. It is determined that the data reception waiting time-out has occurred, and the entire contents of the server information table 32, that is, the flags in the flag field 43b of the operation flag unit 42 and the service information unit 43 are turned off, and the server is inactive and the service is stopped. Yes (S36).

Next, the control operation of the client AP 30 will be described with reference to the flowchart of FIG.
The client AP 30 functions as a communication control unit in claim 1 of the claims. As shown in FIG. 11, the client AP 30 first confirms the presence or absence of a service request from the operator (S4
1) If there is a service request, the communication processing unit 30a of the client AP 30 causes the server information table 3
Server A that should correspond to the requested service with reference to 2
It is determined whether or not the state of P is providing service (S42).

Here, if the corresponding flag of the server information table 32 is ON (service is being provided) (S42).
In YES, the communication processing unit 30a transmits the service request data to the server 1 (S43), receives the response data from the server 1 for the transmitted service request data, and notifies the operator (S44).

On the other hand, if the corresponding flag in the server information table 32 is OFF (service is stopped) (S
(NO in 42), the communication processing unit 30a notifies the operator of the information that the service on the server side is currently stopped without transmitting the service request data (S4).
5).

Since delivery confirmation is not generally carried out for the broadcast data, the broadcast data transmitted by the server 1 may not be properly received by the client _{12 to} client _n 4 side and may be lost. Therefore, although the server 1 is actually operating, the broadcast data is sent to the client ₁
2) To avoid misunderstanding that the information in the server information table of each client is set during non-operation of the server because it was not received by the client _n 4, a timeout judgment is made when waiting for reception of broadcast data. The reference time interval t2 is set to a value that is several times larger than the broadcast data transmission time interval t1, so that the above-mentioned erroneous recognition may occur even if some broadcast data reception omission occurs. It is possible to avoid it.

As described above, the server 1 included in the wireless communication network system of this embodiment has the service providing flag of the service information table 13 according to the service providing status of each AP and the usage status of the hardware resources of the server 1. Is turned on / off, and the transmission process 15 transmits the broadcast data in which the contents of the service information table 13 are set to each client at a predetermined transmission time interval. Furthermore, the client _{12 to the} client _n 4 included in the present wireless communication network system monitor the reception interval of the broadcast data transmitted from the server 1 and receive the broadcast data for a time longer than a predetermined reception time interval. If not, or if it is determined that the service cannot be enjoyed within the predetermined time based on the server operation status information included in the broadcast data, the service request data is not transmitted to the server 1. is there.

[0052] With such a configuration, the client ₁ 2
~ The client _n 4 can know the operating status of the server 1 based on the broadcast data from the server 1, and the non-operating status due to the abnormality or overload of the server 1 itself, the server 1 and the client _{12 to the} client _n 4 It is possible to detect a communication-disabled state due to a communication failure that has occurred between and. Further, in such a case, by stopping the transmission of the service request data from the client side to the server side, it is possible to prevent unnecessary communication traffic from increasing and improve the network utilization efficiency. As a result, it is possible to appropriately detect a failure and improve the reliability of the network, and it is also possible to improve the utilization efficiency of the network.

[Embodiment 2] Another embodiment of the present invention will be described below with reference to FIGS. 1 and 12 to 17. It should be noted that, for convenience of explanation, portions having the same functions as those in the above-described embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The same applies to other embodiments described later.

As shown in FIG. 12, the wireless communication network system according to this embodiment includes one server 1 and n.
Basically, it is composed of _one client 150, client ₂ 51, ... Client _n 52. Additional client ₁ 50, client ₂ 51, ... client _n 52 is provided with an antenna 53, 54, 55, respectively, in the same manner as in Example 1, said server 1, the broadcast data including a service providing information , Is transmitted to each client via the antenna 5 at predetermined constant time intervals t1. By receiving the broadcast data, each client can confirm whether the server 1 is operating and whether each service of the server 1 is being provided or stopped.

[0055] However, for example, as shown in the figure, the antenna 5 of the antenna 5 and the client ₁ 50 of the server 1
Between the 3, when an obstacle 9, such as the radio wave reflecting object is temporarily intervening in some cases the client ₁ 50 is no longer able to temporarily receive broadcast data from the server 1.

In such a case, each of the clients of this embodiment determines whether the cause of the communication failure is on the communication path or on the server 1 itself, so that the server 1 is determined by another predetermined client. Inquire about the operating status of. For example, as shown in the figure, the client ₁ 50, by the obstacle 9, if it can not receive more than during a predetermined broadcast data from the server 1 in advance, the client ₂ 5 adjacent to a predetermined
Relative to 1, and transmits the server information request data (PQ) querying the operating status of the server 1, client ₂ 51
To respond to the client ₁ 50 The results of the reference to its server information table 32 (server information holding means) as the server information response data (PA).

Hereinafter, the process of inquiry and response of the operating status of the server performed between the clients in this way will be described in detail.

First, the configuration of the client included in the wireless communication network system of this embodiment will be described with reference to FIG. For each client on the wireless communication network system is substantially the same configuration, it will be described here by way of client ₁ 50 to Examples. Since the configuration and operation of the server 1 included in the wireless communication network system of the present embodiment are the same as those described in the first embodiment, only the client side will be described below.

[0059] The client ₁ 50 of the present embodiment, FIG. 13
As shown in FIG. 3, in addition to the configuration shown in FIG. 1 in the first embodiment, to store information of other clients to be inquired when the broadcast data from the server 1 cannot be received for a certain time or longer. Client information table 45. Further, instead of the broadcast data reception processing unit 31 described in the first embodiment, the broadcast data sent from the server 1 is received and a response process is performed in response to server information request data from another client. The transmission / reception processing unit 46 is provided. Further, the above-mentioned Example 1
In place of the client AP30, the client AP47 whose operation will be described in detail later is provided.

The client AP 47 assembles service request data and analyzes response data, and at the same time, assigns a communication partner to the server 1 or another client according to the contents of the server information table 32, and the server 1 and the server 1. A data transmitting / receiving unit 47b for performing data transmission / reception processing with the client information table 45
The server information transmitting / receiving unit 47c that transmits / receives the server information to / from another client designated according to the contents of the above.

Here, the operation of the client AP 47 will be described with reference to FIG. The client AP 47 functions as the information requesting means according to claim 2 of the claims. Client AP47 is, (YES in S51) When there is a service request from the operator, its clients by (in this case, the client ₁ 50) refers to the server information table 32 is built, the server 1 is in operation Then, it is confirmed whether or not the requested service is being provided, that is, whether or not the requested service can be processed (S52).

When it is determined in S52 that the processing is possible (YES in S52), the service request data is transmitted to the server 1 (S53), the response data from the server 1 is received, and the result is sent to the operator. (S54). On the other hand, when it is determined in S52 that the server 1 is not in operation, the client identifier registered in the client information table 45 when the transmission / reception processing unit 46 is activated is acquired, and the client having this identifier (in the case of FIG. 12, performs the transmission of server information request data to the client ₂ 51) (S55).

[0063] Further, when the check the contents of the server information response data to the server information request data (S56), the information that the server 1 is in service obtained, communication between the client ₁ 50 and server 1 The operator is notified of the occurrence of a communication error due to a failure on the route (S57). On the other hand, when the information that the server 1 is not in operation is obtained from the contents of the server information response data in S56, the operator is notified that the service request cannot be made due to the server being inactive (S58). ).

The destinations to which the server information request data is transmitted in S55 may be a plurality of clients, and the operation status of the server 1 is comprehensively determined by the server information response data obtained from the plurality of clients in this way. With the configuration for confirming the above, if the communication failure occurs, the cause can be more surely known.

Next, regarding the operation of the transmission / reception processing section 46,
This will be described below with reference to FIG. The transmission / reception processing unit 46 functions as a response unit according to claim 2 of the claims. Transmission / reception processing unit 46
Is the server information table 32 as an initial setting at startup.
Is set to OFF (server is not operating / all services are stopped), the identifier of the server information inquiry client is set in the client information table 45, and the reception monitoring timer 33 is reset (S61).

Next, the presence or absence of received data is confirmed (S6
2) If there is received data, it is checked whether it is broadcast data from the server 1 or server information request data from another client (S63). If the received data is broadcast data, the reception monitoring timer 33 is reset (S64), and the server information table 32 is updated according to the contents of the information section 21 of the received broadcast data (S65).

On the other hand, when the received data is the server information request data in the above S63, the contents of the server information table 32 are referred to check whether or not the server 1 is in operation, and the server information response data is created. , To the inquiry source client (S66).

When the broadcast data is not received for a time longer than the predetermined broadcast data reception time interval t2 (NO in S62 and YES in S67), the broadcast data reception waiting timeout occurs. And the contents of the server information table 32 are all O
FF (server not in operation / service stopped) (S6
8).

Here, an example of the data format of the above server information inquiry data will be shown. As shown in FIG. 16, the server information request data includes a header section 60 and an information section 61. The header section 60 is a section that depends on the communication protocol, and its format is determined by the communication protocol used by the wireless communication network system of the present embodiment. The head portion of the information section 61 is a code section 62 in which a code "CMD1" indicating that this data is server information request data is set. Further, following this code section 62, a client identification number section 63 in which the identification number of the requesting client is set.
Further, behind the client identification number section 63, there is provided a server identification number section 64 in which the identification number of the server whose status is to be inquired is set. It should be noted that a plurality of server identification number parts 62 can be provided, and for example, one client can correspond to a network capable of transmitting and receiving with a plurality of servers.

Next, an example of the data format of the server information response data for the above server information request data will be shown. As shown in FIG. 17, the server information response data is
It is composed of a header section 65 and an information section 66. The header portion 65 is a portion that depends on the communication protocol, and its format is determined by the communication protocol used by the wireless communication network system of this embodiment. The head portion of the information section 66 is a code section 67 in which a code "RSP1" indicating that this data is server information response data is set. Also, behind this code section 67,
A server information section 68 including a server identification number section 68a in which an identification number of a server inquired about information is set and a server operation flag section 68b in which a flag indicating whether or not this server is in operation is set is provided. Has been.
It should be noted that a plurality of the server information units 68 can be provided, and as described above, one client can correspond to a network in which transmission and reception can be performed with a plurality of servers.

As described above, the wireless communication network system of the present embodiment is similar to the system described in the first embodiment, in that the client side is based on the broadcast data transmitted at a predetermined transmission time interval from the server side. It is possible to confirm the operating status of the server side on the server side, and if the broadcast data does not arrive at a client even after the predetermined reception time interval has elapsed, this client is decided in advance. In addition, it is configured to inquire other clients about the operating status of the server. Further, the client, which receives the inquiry about the operation status of the server, creates the server information response data from the contents of the server information table 32 of itself, and transmits it to the client as the inquiry source.

As a result, when each client cannot receive the broadcast data for a time longer than a predetermined reception time interval, whether this is due to a malfunction or overload of the server 1 itself, or between itself and the server 1. It is possible to reliably determine whether or not this is due to the occurrence of a communication failure. As a result, it is possible to accurately understand the cause of the communication abnormality that has occurred on the network, for example, if it is due to a malfunction of the server 1, it is possible to quickly recover from the system down state by immediately starting the recovery work. It will be possible to deal appropriately with
This has the effect of improving the reliability of the network.

[Embodiment 3] Another embodiment of the present invention will be described below with reference to FIGS. 18 to 24.

As shown in FIG. 18, the wireless communication network system according to this embodiment includes one server 71,
n number of clients ₁ 72, client ₂ 73, ... constituted by the client _n 74. Additional server 71 and the clients ₁ 72, client ₂ 73, ...
Client _n 74 has respective antennas 75 and 76
・ Data communication is carried out via 77 ... 78.

Similar to the server 1 of each of the above-mentioned embodiments, the server 71 transmits the broadcast data including the service providing information to each client at a predetermined constant time interval t1. By receiving the broadcast data, each client can confirm whether or not the server 71 is operating and whether each service of the server 71 is being provided or stopped.

[0076] Further, for example, as shown in FIG. 18, between the antenna 75 and the client ₁ 72 of the antenna 76 of the server 71, by an obstacle 9, such as radio wave reflecting object is temporarily interposed client ₁ 72 is the server 71
If you cannot temporarily receive broadcast data from
Similar to the client of the second embodiment described above, the client ₁ 72, by sending the server information request data, to receive the server information response data from the client ₂ 73 to the client ₂ 73, the client ₁ 7
Server 2 is unable to communicate with server 71 due to server 71
It is possible to check whether it is on the communication path or on the communication path.

[0077] In addition, the client ₁ 72 to the present embodiment
Each client of the client _n 74, for example, when the server information request data is transmitted from the client ₁ 72 to the client ₂ 73, the client ₂ 73 transmits the server information response data to the client ₁ 72 and the client ₁ Notification data (indicated by PT in FIG. 18) for notifying the server 71 that there has been a server information transmission request from 72 is transmitted.

[0078] As described above, the server 71, the notification data from the client ₂ 73, the client ₁ 7
2 If any communication failure is informed that has occurred between the That client ₁ 72 that can no longer receive the broadcast data, the client ₁ 7
It operates so as to suppress the data transmission to 2.

The configuration and operation of the server 71 and the like included in the wireless communication network system of this embodiment will be described below.

First, the configuration of the server 71 will be described with reference to FIG. As shown in the figure, the server 71 is similar to the server 1 described in the first embodiment,
Server AP ₁ 80 for providing various services to the service request from each client, the server AP ₂ 81,
The server AP _k 82, the service information table 13 in which the service providing flag indicating whether or not the service of the server AP is currently provided is stored in association with the identifiers of these APs, and the hardware resources in the server 1. Process for monitoring the usage status of CPU (CPU load rate, disk usage, memory usage, etc.), sending process 15 for creating and sending broadcast data, and measuring the sending interval of broadcast data And a data transmission / reception processing unit 16 configured by hardware and software to control transmission / reception of data.

[0081] In addition, the above-mentioned server AP ₁ 80~AP _k 8
2 of each of the analysis and of the service request data transmitted from the client, the communication processing unit ₁ 80a to the assembly, such as the response data to the client, the communication processing unit ₂ 81
a ... Communication processing unit _k 82a is included.

In addition to the above-mentioned configuration, the server 71 also informs the presence / absence of a fault on the communication path between the client and the notification data reception processing section 83 for receiving and processing the notification data from the client. And a failure information table 84 stored as. The failure information table 84 stores a client identification number and a failure flag indicating the presence / absence of a failure on the communication path to the client, and the notification data reception processing unit 83 receives the notification data. Each time, it is updated according to the content of the received notification data. The notification data reception processing unit 83 functions as a transmitting / receiving unit according to claim 3 of the claims.

Here, the structure of the above notification data will be described. As described above, the notification data is created on the client side and transmitted to the server side, and includes a header section 90 and an information section 91 as shown in FIG. In the information section 91, a code field 91a in which a code "CMD2" indicating that this data is notification data is set, and an identification number field in which the identification number of the requesting client who has made the server information transmission request is set. It consists of 91b.

Next, the operation of the notification data reception processing section 83 will be described with reference to FIG. The notification data reception processing unit 83 uses the failure information table 84 as an initial setting.
Set all contents of OFF to OFF (no failure) (S10
1) Wait for notification data to be received from the client (S
102). When the notification data is received, the failure flag corresponding to the client identification number set in the identification number field 91b of the received notification data is set to ON (with a failure) (S103).

[0085] Next, an example of operations of the server AP ₁ 80, will be described with reference to FIG. 22. Although the server 71 there are a plurality of servers AP, since these are to substantially the same operation, wherein the server AP ₁ 80
Will be described as an example. The server AP 180 _first performs service start processing such as initial setting, and at the end of this processing, turns on the service providing flag of the service information table 13.
(Service is being provided) (S71). Thereafter, it is checked whether the service request from the client ₁ 72 to client _n 74 (S72), if there is a service request (at S72 YES), the failure flag corresponding to the service requesting client in failure information table 84 It is set to OFF (no failure) (S73), and service processing according to the service request is performed (S74).

After that, when transmitting the result of the above service processing as response data, the server AP 180 _first refers to the failure flag in the failure information table 84 and then on the communication path to the client to which the response data is sent. If there is no failure (S75), the response data is transmitted only when there is no failure (YES in S75) (S76). On the other hand, if there is a failure on the communication path to the client to which the response data is transmitted (S75
If NO), the process proceeds to S77 by avoiding S76, that is, the transmission of the response data is stopped.

[0087] Thereafter, the server AP ₁ 80, when the next new service request is issued within a predetermined proper response time to confirm whether it is possible to process the service request (S7
7) If it is determined that the processing cannot be performed within the proper time (NO in S77), the service information table 13
If the service providing flag of is set to OFF (service is stopped) (S78), and the service processing up to immediately before is completed and a response is possible within an appropriate time (YES in S77), the service information table 13 The service provision flag of is turned ON (service is being provided) (S79.S
80), accept the next service request.

[0088] server AP ₁ 80 is, more S72~S8
The processing of 0 becomes the service end time (Y in S81
Until ES), the service provision flag of the service information table 13 is turned off and the service ends (S).
82).

Next, it will be described below configuration and operation of the client ₁ 72 to client _n 74 of the present embodiment. The client ₁ 72 to client _n 74
When the configuration on the difference between the client ₁ 50 to client _n 52 described in the embodiment 2, as shown in FIG. 23, the client ₁ 72 to client _n 7 of the present embodiment
4 is that a transmission / reception processing unit 92 whose operation will be described in detail below is provided instead of the transmission / reception processing unit 46 described in the second embodiment. The transmission / reception processing unit 92 functions as a notification unit according to claim 3 of the claims.

[0090] In this case, the client ₁ 72 to the present embodiment
The operation of the transmission / reception processing unit 92 included in the client _n 74 will be described with reference to FIG. The transmission / reception processing unit 92 first sets all the contents of the server information table 32 to OFF (server not in operation / all services stopped) as an initial setting at startup, and sets the identification number of the inquired client of the server information to the client information table. At the same time, the reception monitoring timer 33 is reset to 45 (S111).

Next, the transmission / reception processing unit 92 confirms the presence or absence of the received data (S112), and if there is the received data, the received data is the broadcast data from the server 71 or the server from another client. It is checked whether the data is information request data (S113). If the received data is broadcast data, the reception monitoring timer 33 is reset (S11
4) The information in the server information table 32 is updated according to the contents of the information part 21 of the broadcast data (S115).

On the other hand, when it is determined in S113 that the received data is the server information request data, the transmission / reception processing unit 92 refers to the contents of the server information table 32 to determine whether the server 71 is operating or not operating. Is confirmed, server information response data is created and transmitted to the client as the inquiry source (S116). Furthermore, the identification number of the inquiry source client is set in the notification data, and this notification data is transmitted to the server 71 (S117).

If the broadcast data is not received from the server 71 for a time longer than the predetermined reception time interval t2 (NO in S112 and YES in S118), it is determined that the reception waiting time of the broadcast data has timed out. Then, all contents of the server information table 32 are turned off.
(Server not in operation / service stopped) (S11)
9).

As described above, the server 71 of the wireless communication network system of this embodiment is provided with the client information table 45 for storing the information indicating the communication status with the client, and the client of this wireless communication network system. _{When each of the} 172 to client _n 74 receives a server information inquiry (server information request data) from another client, the server information response data is sent to the client based on the contents of its own server information table 32. Create and send
The server 71 is notified of the identification number of the client who made the inquiry. Furthermore, the server 71
When the notification data is received, the data is not transmitted to the client who made the inquiry about the server information.

As a result, if each client cannot receive the broadcast data from the server 71 even after the predetermined reception time interval elapses, each client does not receive the broadcast data. However, it is possible to reliably determine whether the error is due to a malfunction or overload of the server 71 itself, or due to a communication failure that has occurred in the communication path between itself and the server 71. Server 71 for the client who made the inquiry
By restricting data transmission from the server 71
Since unnecessary data transmission to the client, which is highly unlikely that the transmission data from the network will reach accurately, is avoided, it is possible to prevent an increase in unnecessary traffic volume in the entire network and improve communication efficiency. Play.

The above-mentioned embodiments do not limit the present invention, and various modifications can be made within the scope of the invention. For example, in each of the above-described embodiments, a network in which a plurality of clients correspond to one server has been described as an example, but the network configuration is not limited to this, and a service request from each client to a plurality of servers is provided. The present invention can be applied to networks having various configurations such as a network capable of performing the above.

In Japanese Patent Laid-Open No. 4-235652, an unauthorized terminal is used in a network system in which when a terminal communicates with another terminal, the relay terminal determines whether or not to allow data relay. In order to prevent access from the terminal, the identification numbers of the sending terminal and relay terminal are embedded in the data packet, and each terminal internally holds the identification number of the access-permitted terminal as an information table. There is disclosed a method of checking whether or not is listed as the identification number of the access-permitted terminal in the internal information table, and notifying the access terminal of the access refusal when a mismatch occurs. However, the method disclosed in the above publication is intended to ensure security in a communication system, and neither consideration nor improvement or improvement of communication efficiency of the communication system is disclosed or suggested, and the method of the present invention Is different.

[0098]

As described above, in the wireless communication network system according to claim 1 of the present invention, is it possible for the server to provide the service within a predetermined response time in response to the service request from the client? Communication control is provided, which includes broadcast data transmitting means for generating broadcast data including information indicating whether or not it is transmitted to the client at a predetermined transmission time interval, and which is provided in the client and transmits a service request to the server. If the means does not receive the broadcast data sent from the server within a predetermined reception time interval, or the service cannot be provided within the predetermined response time in the received broadcast data. If the information indicating that is included, the service request is not transmitted to the server.

According to the above configuration, when the broadcast data transmitted from the server to the client at a predetermined transmission time interval does not arrive at the client even after the predetermined reception time interval, some abnormality occurs in the server. Therefore, it can be determined that the transmission of broadcast data has become impossible, or that some failure has occurred in the communication path between the server and the client. It is possible to appropriately detect whether or not the communication can be executed normally.

Furthermore, if the communication control means provided in the client does not receive the broadcast data even after a predetermined reception time interval elapses, or if the received broadcast data receives a service within a predetermined response time. If it includes information indicating that the service request cannot be provided, the service request from the client is reliably delivered to the server and processed by operating so as not to send the next service request. The service request is transmitted only when it is determined that there is an effect that unnecessary communication traffic is prevented from occurring in the entire network and communication efficiency can be improved.

Further, in the wireless communication network system according to the second aspect of the present invention, the server creates the broadcast data including the server operation information indicating the operation status of the server and transmits it to the client at a predetermined time interval. A broadcast data transmission unit is provided, and the client data holding unit holds the server operation information included in the broadcast data every time the client receives the broadcast data from the server, and the broadcast data transmitted from the server. The information request means for creating server information request data including an inquiry about the operating status of the server and transmitting it to another client when no incoming call arrives after a predetermined reception time interval, and the server information request data from another client. Creates server information response data including server operation information held in the server information holding means when received Te is a configuration that includes a response means for transmitting to said client.

According to the above arrangement, when the broadcast data from the server does not arrive at a certain client even after a predetermined reception time interval, the information requesting means inquires of another client about the operating status of the server. The client communicates with the server by sending the server information request data, and the client receiving the server information request data sets the latest server operation information held by itself in the server information response data and returns it. When an error occurs, determine whether the cause of this error is in the server itself or in the communication path with the server.
It can be confirmed by the information obtained from other clients. As a result, it is possible to properly detect the cause of the communication abnormality that has occurred on the network, and it is possible to prevent deterioration of the reliability of the system.

Further, in the wireless communication network system according to the third aspect of the present invention, when the client receives the server information request data, the notification data including the identifier of the client as the transmission source of the server information request data is created. When the notification data is received by the transmission / reception means provided in the server for transmitting / receiving data to / from the client, the identifier included in the received notification data is sent to the server. This is a configuration in which the transmission of data to the client that has it is stopped.

According to the above configuration, the server side knows the client in which the communication abnormality occurs with itself and prevents the data transmission to this client, so that the communication failure occurs. It is possible to avoid useless transmission to a client that transmission data is unlikely to reach, and as a result, it is possible to suppress useless communication traffic in the entire network and improve communication efficiency. Play.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a client included in a wireless communication network system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an outline of a configuration of a server included in the wireless communication network system.

FIG. 3 is an explanatory diagram showing an overall configuration of the wireless communication network system.

FIG. 4 is an explanatory diagram showing an example of a service information table included in the server.

FIG. 5 is a flowchart showing a control operation of a server AP included in the server.

FIG. 6 is a flowchart showing a control operation of a monitoring process included in the server.

FIG. 7 is a flowchart showing a control operation of a transmission process included in the server.

FIG. 8 is an explanatory diagram showing a structure of broadcast data transmitted from the server to a client.

FIG. 9 is an explanatory diagram showing the structure of a server information table provided in the client and updated based on the broadcast data.

FIG. 10 is a flowchart showing a control operation of a broadcast data reception processing unit included in the client.

FIG. 11 is a client AP included in the client.
5 is a flowchart showing the control operation of the first embodiment.

FIG. 12 is an explanatory diagram showing an overall configuration of a wireless communication network system according to another embodiment of the present invention.

FIG. 13 is a block diagram showing an outline of a configuration of a client included in the wireless communication network system.

FIG. 14 is a client AP included in the client.
5 is a flowchart showing the control operation of the first embodiment.

FIG. 15 is a flowchart showing a control operation of a transmission / reception processing unit included in the client.

FIG. 16 is an explanatory diagram showing a structure of server information request data (PQ) transmitted from a client that cannot communicate with a server to another client in the wireless communication network system.

FIG. 17 is an explanatory diagram showing a structure of server information response data (PA) returned by the client that receives the server information request data.

FIG. 18 is an explanatory diagram showing an overall configuration of a wireless communication network system in still another embodiment of the present invention.

FIG. 19 is a block diagram showing an outline of a configuration of a server included in the wireless communication network system.

FIG. 20 is an explanatory diagram showing a structure of notification data for a client that has received the server information request data in the wireless communication network system to notify the server of a sender client of the server information request data.

FIG. 21 is a flowchart showing a control operation of a notification data reception processing unit included in the server.

FIG. 22 is a flowchart showing a control operation of a server AP included in the server.

FIG. 23 is a block diagram showing a schematic configuration of a client included in the wireless communication network system.

FIG. 24 is a flowchart showing a control operation of a transmission / reception processing unit included in the client.

FIG. 25 is a flowchart showing an operation on the client side in a conventional server / client type wireless communication network system.

[Explanation of symbols]

1 Server 2 Client ₁ 15 Transmission Process (Broadcast Data Transmission Means) 30 Client AP (Communication Control Means) 47 Client AP (Information Request Means) 46 Transmission / Reception Processing Unit (Response Means) 83 Notification Data Reception Processing Unit (Transmission / Reception Means) 92 Transmission / reception processing unit (notification means)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04B 15/00 H04B 7/26 109M

Claims (3)

[Claims] 1. A wireless communication network system for performing data communication by wireless communication between a server and a client, wherein the server can provide a service within a predetermined response time in response to a service request from the client. It is provided with a broadcast data transmitting unit that creates broadcast data including information indicating whether or not it is possible and transmits it to the client at a predetermined transmission time interval, and is provided in the client and transmits a service request to the server. If the communication control means does not receive the broadcast data transmitted from the server within a predetermined reception time interval, or if the service is provided within the predetermined response time in the received broadcast data. If the information indicating that it is impossible is included, the service request is not sent to the server. Line communication network system. 2. A wireless communication network system for performing data communication by wireless communication between a server and a client, wherein the server creates broadcast data including server operation information indicating an operation status of the server, and a predetermined time From the server, there is provided broadcast data transmission means for transmitting to the client at intervals, and each time the client receives the broadcast data from the server, server information holding means for holding server operation information included in the broadcast data. Information requesting means for creating server information request data including an inquiry about the operating status of the server and transmitting it to another client when the broadcast data to be transmitted does not arrive even if a predetermined reception time interval has elapsed, When the server information request data is received from the client, the server held in the server information holding means A wireless communication network system, characterized in that to create the server information response data including operation information and a response means for transmitting to said client. 3. When the client receives the server information request data, the client further comprises notifying means for creating notification data including an identifier of a client as a sender of the server information request data and transmitting the notification data to the server. When the transmitting / receiving means provided in the server for transmitting / receiving data to / from the client receives the notification data, it stops transmitting the data to the client having the identifier included in the received notification data. The wireless communication network system according to claim 2.