Abstract:
A telephone exchange apparatus includes a memory which stores a plurality of resource information for executing mutually different plural communication service functions, a recorder which records communication signals for processing in the each resource information, on a recording medium, a processor which processes the communication signals based on the corresponding resource information stored in the memory, and a controller which controls to manage the communication signals on the recording medium by each resource, and releases the corresponding resource area on the recording medium according to the communication service function requesting to release.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-400791, filed Nov. 28, 2003, the entire contents of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a telephone exchange apparatus for executing communication service functions relating to any one of exchanges between mutual extensions, between an extension and a line wire, and between mutual line wires, and more particularly to a telephone exchange apparatus and a control method for the telephone exchange apparatus intended to improve recovery from failure. 
   2. Description of the Related Art 
   Hitherto, in office and other buildings, the telephone exchange apparatuses such as a key telephone apparatus and a private branch exchange (PBX) have been widely used. This kind of telephone exchange apparatus contains telephone sets or the like as extension terminals, and enables calls by switching and connecting between the extension terminals and the external network such as a public telephone network, and between mutual extension terminals. 
   In such a telephone exchange apparatus, if any abnormality occurs in a resource for executing the communication service function, such a resource failure cannot be recognized by a maintenance engineer or the like. Therefore, the telephone exchange apparatus may be left over for a long time while the resource is abnormal, and it often causes troubles in management of the apparatus. 
   Accordingly, there have been proposed a method of initializing the process by determining resource abnormality and using this abnormal resource (for example, see Jpn. Pat. Appln. KOKAI Publication No. 2000-267869), and a method of releasing, at the time of a call, an illegally used resource by checking whether or nor a resource corresponding to the call is used illegally (for example, see Jpn. Pat. Appln. KOKAI Publication No. 2001-268607). 
   In these methods, however, the corresponding resource cannot be released if failure occurs in the midst of execution of communication service function. Also in such methods, the normal resource may be adversely influenced if the resource is released or the process using the corresponding resource is initialized during execution of the communication service function. 
   BRIEF SUMMARY OF THE INVENTION 
   It is hence an object of the invention to provide a telephone exchange apparatus and a control method for the telephone exchange apparatus intended to act effectively against operation failure possibly occurring in every communication service function. 
   According to an aspect of the present invention, there is provided a telephone exchange apparatus for accommodating a plurality of extensions adapted to connect telephone terminals to each terminal end and connecting at least one line wire, the telephone exchange apparatus executing communication service functions relating to at least one of switches between mutual extensions, between an extension and a line wire, and between mutual line wires, comprising: a memory which stores a plurality of resource information for executing mutually different plural communication service functions; a recorder which records communication signals for processing in the each resource information, on a recording medium; a processor which processes the communication signals on the recording medium based on the corresponding resource information stored in the memory; and a controller which controls to manage the communication signals on the recording medium by each resource, and releases the corresponding resource area on the recording medium according to the communication service function requesting to release. 
   According to another aspect of the present invention, there is provided a control method for use in a telephone exchange apparatus for accommodating a plurality of extensions adapted to connect telephone terminals to each terminal end and connecting at least one line wire, the telephone exchange apparatus executing communication service functions relating to any one of exchanges between mutual extensions, between an extension and a line wire, and between mutual line wires, the control method comprising: storing a plurality of resource information for executing mutually different plural communication service functions; recording communication signals for processing in each resource information, on a recording medium, and managing the communication signals on the recording medium by each resource, and releasing the corresponding resource area on the recording medium according to the communication service function requesting to release. 
   Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention. 
       FIG. 1  is a block diagram showing a schematic configuration of an exchange system according to a first embodiment of the present invention; 
       FIG. 2  is a block diagram showing a connection state of a time switch, a control unit and a storage unit shown in  FIG. 1 ; 
       FIG. 3  is a diagram showing an example of stored contents of a resource table shown in  FIG. 2 ; 
       FIGS. 4A and 4B  are a diagram showing a corresponding relation between a communication service function and a resource according to the first embodiment; 
       FIG. 5  is a flowchart showing control procedures of a control unit in an exchange system according to a second embodiment of the present invention; and 
       FIG. 6  is a flowchart showing control procedures of a control unit in an exchange system according to a third embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the drawings, embodiments of the invention will be specifically described below. 
   FIRST EMBODIMENT 
     FIG. 1  is a block diagram showing a schematic configuration of a switching system according to a first embodiment of the invention. 
   The switching system comprises, as shown in the diagram, a main apparatus  1 , and a plurality (maximum i pieces) of extension terminals  2  ( 2 - 1  to  2 -i) which are arbitrarily connected thereto by way of individual communication ports. The extension terminals  2  include, for example, key telephone sets and standard telephone sets. 
   The main apparatus  1  further includes a time switch  11 , a plurality (j pieces) of trunk line interface circuits  12  ( 12 - 1  to  12 -j) (hereinafter referred to as trunk line IF  12 ), a plurality (i pieces) of extension interface circuits  13  ( 13 - 1  to  13 -i) (hereinafter referred to as extension IF  13 ), a control unit  14 , a storage unit  15 , and a data highway interface unit  16  (hereinafter referred to as DHW IF  16 ), and the time switch  11 , trunk line IF  12 , and extension IF  13  are mutually connected by way of a PCM highway  17 . 
   Further, the trunk line IF  12 , extension IF  13 , and DHW IF  16  are mutually connected by way of a data highway  18 . The time switch  11 , control unit  14 , storage unit  15 , and DHW IF  16  are mutually connected by way of a CPU bus  19 . 
   The time switch  11  arbitrarily switches and connects the mutual extension IF  13 , and trunk line IF  12  and extension IF  13  according to the control of the control unit  14 . 
   In the trunk line IF  12 , office lines L (L- 1  to L-j) of ISDN network, public telephone network and private lines as a line wire are connected as required. The trunk line IF  12  executes trunk line interface operation about the connected office lines L. The trunk line interface operation includes conversion of an audio signal (analog) to be supplied through the office line L into a PCM signal, conversion of a PCM signal to be supplied through the time switch  11  into an audio signal (analog), monitoring of state of the office line L, and transmission of various signals to the network connected by the office lines L. Further, the trunk line IF  12  transmits/receives various control information about the trunk line interface operation to/from the control unit  14  by way of the data highway  18 , DHW IF  16 , and CPU bus  19 . 
   The extension terminals  2  are connected as required to the extension IF  13 . The extension IF  13  executes extension interface operation about the connected extension terminals  2 . The extension interface operation includes extraction of a PCM signal to be outputted from the extension terminal  2  from the PCM highway  17 , monitoring of state of the extension terminal  2 , and transmission of various signals to the extension terminal  2 . The extension IF  13  also transmits/receives various control information about the extension interface operation to/from the control unit  14  by way of the data highway  18 , DHW IF  16 , and CPU bus  19 . 
   The DHW IF  16  transmits/receives data between the data highway  18  and CPU bus  19 . 
   The control unit  14  processes according to the operation program stored in the storage unit  15 , whereby the time switch  11 , trunk line IF  12 , and extension IF  13  are supervised and controlled, and the operation of the main apparatus  1  is realized. 
   The storage unit  15  stores the operation program of the control unit  14  and other various data used perpetually. 
     FIG. 2  is a block diagram showing the connection state of the time switch  11 , control unit  14 , and storage unit  15 . 
   In the main apparatus  1 , as shown in the diagram, objects of control are divided into a circuit, a slot, a rack, and a system. The storage unit  15  stores programs and process order data determined by the user, and various resource areas  151  for various service operations, and the area is acquired or released dynamically by start or end of service. Each resource is managed by the resource releasing process of each circuit, each slot, each rack, and each system. 
   The storage unit  15  also includes a resource table  152  having stored therein setting information showing vacancy or occupancy of each source, about each one of the communication service functions as shown in  FIG. 3 . 
   In such configuration, the processing operation will be explained. 
   (Ordinary Operation) 
   (1) Outgoing from Extension to ISDN Trunk 
   When outgoing to an ISDN trunk from a certain extension, first, in order to store the dialed number, an outgoing dial accumulation area is captured out of the resource area  151 . When all dials are entered, the numbers are analyzed, and the trunk to be captured is determined. Referring to the trunk usage state in the resource area  151 , if the trunk attempted to be captured has been already used, a next candidate is searched, or a busy signal is returned to the transmission side. If the trunk attempted to be captured is not used, the trunk is set in the usage state. Next, to compile an ISDN message to be sent out to the network, the ISDN message accumulation of the resource area  151  is urged, and the ISDN message is created and transmitted to the trunk. 
   (2) Incoming from ISDN Trunk 
   When incoming from the ISDN trunk, the trunk usage state of the resource area  151  is set in busy state. Keeping an ISDN message accumulation area in the resource area  151 , the ISDN message received from the network is stored in this area, and the ISDN message is analyzed. As a result of analysis, when the incoming destination is determined, if the incoming destination has been already used, camp-on registration is recorded in the camp-on registration state area of the resource area  151 , and the camp-on state is established. 
   This is the normal system process of ISDN trunk outgoing and incoming. If an area is in shortage, the process is as follows. 
   (3) If Outgoing Dial Accumulation Area Cannot be Captured 
   As for outgoing, due to shortage of outgoing dial accumulation area, outgoing to trunk or extension is all disabled. There is no problem about incoming. 
   (4) If Trunk Usage State Area Cannot be Captured 
   The trunk state cannot be held, and all trunk outgoing and incoming are disabled. There is no problem about extension outgoing and incoming. 
   (5) If ISDN Message Accumulation Area Cannot be Captured 
   ISDN message cannot be created and held, and ISDN extension and ISDN trunk outgoing and incoming are disabled. Analog extension and analog trunk outgoing and incoming are enabled. 
   (6) If Camp-on Registration State Area Cannot be Captured 
   In trunk incoming, if incoming destination is busy, camp-on is disabled. Outgoing is enabled. Incoming is possible if incoming destination is not busy. 
   Thus, even if a certain area (resource) cannot be acquired, all system call processes are not disable, and possible call process and impossible call process occur depending on the type of the area not acquired (resource in shortage). Accordingly, if all resources are released by system resetting, adverse effects are caused on the process of normal operation. 
   Accordingly, the resetting range is defined as shown in  FIG. 4A , and the resource and the service are related as shown in  FIG. 4B , and the resetting range of a specified resource is defined as follows. 
   Of the specified resources, if there is any terminal accommodated in the port specified to be reset, it is released. 
   Of the specified resources, if there is any terminal accommodated in the slot specified to be reset, it is released. 
   Of the specified resources, if there is any terminal accommodated in the rack specified to be reset, it is released. 
   Specified resources are released. 
   In the resource table  152 , merely speaking, outgoing service relates to all resources of 1 to 3, and analog extension outgoing relates to outgoing dial accumulation area of 1. 
   According to this resource table  152 , the resource specifying range is defined as follows. 
   (Resource Used by the Demanding Service Itself) 
   In the case of analog extension outgoing, the outgoing dial resource of 1 is specified. 
   (Resource Used by Service One Rank Higher) 
   In the case of analog extension outgoing, the resources (outgoing dial accumulation area, ISDN message area) about the extension outgoing (outgoing to analog extension, outgoing to ISDN extension) are specified. 
   (Resource Used by Service Another Rank Higher) 
   In the case of extension outgoing, all resources (outgoing dial accumulation area, ISDN message area, trunk usage state) about outgoing service (trunk ISDN outgoing, analog trunk outgoing, analog extension outgoing, ISDN extension outgoing) are specified. 
   Thus, by defining the services hierarchically, the highest rank expresses all services provided by the main apparatus  1 . Herein, they are called z (all resources). 
   By such definition, by resetting the services by combination of a resetting range of specified resources of A to D, and a specifying range of resources of a to z, the services can be reset in steps. 
   (1-1) The port to which the terminal having a problem is connected is released if the outgoing dial accumulation area is used. 
   (1-2) The port to which the terminal having a problem is connected is released if the outgoing dial accumulation area or ISDN message accumulation area is used. 
   (1-3) The port to which the terminal having a problem is connected is released if the outgoing dial accumulation area or ISDN message accumulation area or trunk usage state area is used. 
   (1-4) The port belonging to the same slot as the terminal having a problem is released if the outgoing dial accumulation area is used. 
   (1-5) The port belonging to the same slot as the terminal having a problem is released if the outgoing dial accumulation area or ISDN message accumulation area is used. 
   Thereafter, the resource releasing range is similarly expanded in steps, and the fault is remedied. Finally, zD (resetting of all services in the system) is executed. 
   After releasing the resource in the specified range, the event having a problem is processed again. When the problem is not solved, the above procedure is executed, that is, the resources in the range one rank higher are released automatically, so that a system of higher reliability can be constructed. 
   Thus, according to the first embodiment, the control unit  14  manages the communication signals such as ISDN messages recorded in the resource area  151  of the storage unit  15  by resource classification, and controls to release the corresponding resource area  151  on the storage unit  15  by the communication service function demanding release. Therefore, without causing effects on other resources, only the resource having abnormality can be released by force. 
   Also in the first embodiment, on the basis of setting information of each resource information accumulated and managed in the resource table  152 , appropriate resource releasing process can be executed in a simple procedure. 
   SECOND EMBODIMENT 
     FIG. 5  is a flowchart shoring process procedures of a control unit  14  in an exchange system according to a second embodiment of the present invention. 
   First, suppose a user of an extension terminal  2 - 1  turns the dial as outgoing operation to the extension terminal  2 - 2 . As a result, the control unit  14  records this dial operation information in an area other than the resource area  151  in the storage unit  15  as an event (step ST 5   a ). The control unit  14  records the event in an area corresponding to the resource area  151 , and executes the processing (step ST 5   b ). 
   In succession, the control unit  14  monitors whether a trouble about the corresponding resource has occurred or not during the event process (step ST 5   c ), and terminates the event process if no problem occurs. 
   On the other hand, if a problem about the corresponding resource occurs during the event process (Yes), the control unit  14  records the trouble in the storage unit  15  (step ST 5   d ), and determines whether or not a similar problem has occurred in the past (step ST 5   e ). This is a first trouble (No), and the control unit  14  reads out the resetting range from the resource table  152  (step ST 5   f ), releases the corresponding resource in the range (step ST 5   g ), updates the trouble occurrence status management area (step ST 5   h ), reads out the event already recorded in the storage unit  15  (step ST 5   i ), and transfers to step ST 5   b.    
   If the problem is not solved by executing the event process again, the control unit  14  expands the resource releasing range according to the resource table  152 , and determines whether or not to repeat the process until coinciding with the predetermined range or the trouble is solved by other means (step ST 5   j ). In this case, if necessary to process again (Yes), the control unit  14  expands the releasing resource range by one step (step ST 5   k ), and transfers to step ST 5   g.    
   If not necessary to process again (No), the control unit  14  terminates the event process. 
   In this way, according to the second embodiment, if a trouble occurs during execution of the communication service function, the control unit  14  automatically releases the corresponding resource area  151  in the storage unit  15 . Therefore, the resource trouble does not spread to other resources, and occurrence of no call or occurrence of system down can be prevented. 
   In the second embodiment, also, after resource releasing, the corresponding event is read out from the storage unit  15 , and the corresponding communication service function is executed again. Therefore, it is not necessary to start the communication service function in process from the beginning, and the operation can be restored quickly without having to wait for restoring operation. 
   THIRD EMBODIMENT 
     FIG. 6  is a flowchart shoring process procedures of a control unit  14  in an exchange system according to a third embodiment of the present invention. 
   First, suppose the user of the extension terminal  2 - 1  turns the dial as outgoing operation to a subscriber terminal of the ISDN network. As a result, the control unit  14  records this dial operation information in an area other than the resource area  151  in the storage unit  15  as an event (step ST 6   a ). The control unit  14  records the event in an area corresponding to the resource area  151 , and executes the processing (step ST 6   b ). 
   In succession, the control unit  14  monitors whether a trouble about the corresponding resource has occurred or not during the event process (step ST 6   c ), and terminates the event process if no problem occurs, and forms a communication link with the ISDN network. 
   On the other hand, if a problem about the corresponding resource occurs during the event process (Yes), the control unit  14  records the trouble in the storage unit  15  (step ST 6   d ), and determines whether or not a similar problem has occurred in the past (step ST 6   e ). This is a first trouble (No), and the control unit  14  reads out the resource information about analog extension outgoing from the resource table  152  (step ST 6   f ), releases the corresponding resource about the port having a trouble (step ST 6   g ), updates the trouble occurrence status management area (step ST 6   h ), reads out the event already recorded in the storage unit  15  (step ST 6   i ), and transfers to step ST 6   b.    
   If the problem is not solved by executing the event process again, the control unit  14  acquires the resource information about the extension outgoing from the resource table  152  (step ST 6   j ), and transfers to step ST 6   g  again. 
   Yet, if the problem is not solved by executing the event process, the control unit  14  acquires the resource information about the outgoing service of one step higher from the resource table  152  (step ST 6   k ), and transfers to step ST 6   g  again. 
   Still more, if the problem is not solved by executing the event process, the control unit  14  acquires the resource information about the analog extension outgoing from the resource table  152  (step ST 6   l ), releases the corresponding resource about the slot having a trouble (step ST 6   m ), and transfers to step ST 6   h  again. 
   Such process is repeated n times until the problem is solved while expanding the range. If the problem is not solved after repeating n times, the control unit  14  resets the hardware in the extension IF  13 , trunk line IF  12 , and main apparatus  1 . 
   In this way, according to the third embodiment, if a trouble occurs during execution of the communication service function, the control unit  14  automatically releases the corresponding resource area  151  in the storage unit  15 , and the function having the trouble is released and processed in the resource unit. If not recovered, the resetting range is expanded in gradual steps, so that it is possible to recover from trouble without giving any substantial effects on other services. 
   In the third embodiment, if not recovered from trouble by releasing the resource, by resetting the hardware in the extension IF  13 , trunk line IF  12 , and main apparatus  1 , it is possible to restore quickly from trouble, and a system of higher reliability can be provided. 
   OTHER EMBODIMENTS 
   The invention is not limited to these embodiments alone. For example, in the third embodiment, by expanding the application range of resetting service about the port, if not restored, the application range of resetting service is expanded similarly about the slot. But not limited to this extent, by further expanding to the rack, more quick service restoration is possible. 
   Moreover, a system of higher reliability can be constructed by applying this procedure automatically, from the trouble occurrence port and trouble occurrence service contained in the error message outputted from the system. 
   In the event of trouble, instead of expanding the application range in gradual steps, resetting of service may be applied to the entire system from the beginning, and faster service restoration is possible. For example, due to resource usage status abnormality about line wire outgoing, if the user requests declaration of impossibility of line wire outgoing by the entire system, the system manager can release the entire resources about the line wire outgoing service in the entire system, without consideration of detailed investigation or system reset timing (resetting in lunch time or after work). Therefore, it is possible to restore from trouble promptly without giving any effect on extension communication or other services. 
   In the second and third embodiments, examples of releasing process of the corresponding resource at the time of occurrence of a trouble have been explained. But not limited to these examples, the resource may be released on the condition of user&#39;s request or illegal use of the resource. 
   Also in these embodiments, examples of setting the resource table and resource area in the same storage unit have been explained, but they may be also provided on different storage units. 
   Further, the system type and configuration, main apparatus construction, stored contents in the resource table, and resource releasing procedures may be changed and modified without departing from the true spirit and scope of the invention. 
   Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.