Abstract:
The present invention relates to a subscriber control module having a test apparatus suitable for testing internal routes in an Asynchronous Transfer Mode ATM exchange system for improved reliability and effective maintenance thereof. A subscriber control module having testing functions makes it possible that internal whole routes in the exchange system under the control by maintenance control module inside the system can be tested through the use of subscriber switching network and connection switching network. Further, a test apparatus of the present invention placed inside the exchange system can test ATM subscribers with individually different rates, configured in such a way to be identical with boards used in the exchange system so that the test apparatus can be installed inside the exchange system.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a subscriber control module having a test apparatus which is suitable for testing internal routes in an Asynchronous Transfer Mode ATM exchange system, so that improved reliability and effective maintenance thereof are secured. 
     2. Description of the Conventional Art 
     For the use of test apparatus modules for Asynchronous Transfer Mode exchange system, there has been, conventionally, used different test apparatus modules for different rates subscribers. However, relatively bulky modules can be coupled thereto only from the external of the exchange system, without being installed inside ATM exchange system. 
     Thus, it is required to use the number of test apparatus modules corresponding to the subscribers with different rates, respectively, selected to be tested, and further such many modules are to be coupled from the external of the exchange system. 
     There occurs the problem in that internal routes in the exchange system cannot be tested under the control of a maintenance control module existing inside the system. 
     SUMMARY OF THE INVENTION 
     Therefore, the present invention aimed to solve the above-mentionend problem provides a subscriber control module having testing functions by which all internal routes in the exchange system under the control by maintenance control module inside the system can be tested through the use of subscriber switching network and connection switching network. A test apparatus of the present invention placed inside the exchange system can test ATM subscribers at individually different rates, configured in such a way to be identical with boards used in the exchange system so that the test apparatus can be installed inside the exchange system. 
     To achieve the object of the present invention, there is provided a subscriber control module comprising: cell multiplexing/demultiplexing means which is coupled to a subscriber switching network module through the connections between internal modules, multiplexes and transports cells into the subscriber switching network module, demultiplexes cells received through the subscriber switching network module and transports them depending upon the destinations; call-connecting control means coupled to the cell multiplexing/demultiplexing means and for receiving and tansporting the internal control cells, outputting warning messages of Off_Alm and Fun_Alm, and communication with a maintenance control module in a central exchange subsystem to control the call connections; test functioning means which analyzes the received control cells in response to the receipt of internal route testing commands through the control cells incoming from the call-connecting control means and generates and transports the test cells appropriate to the internal testing routes and which analyzes the test cells received through the internal routes, and by which the results under the internal control cell format are reported to the call-connecting control means, and which outputs the Off_Alm, Fun_Alm warning messages; and warning message collecting means which collects warning messages generated from the test functioning means, call-connecting control means and cell multiplexing/demultiplexing means, and also collects warning messages generated from respective modules in the local exchange subsystem, and by which the results under the internal message format are reported to the call-collecting control means. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood to following detailed description taken in conjunction with the accompanying drawings, wherein: 
     FIG. 1 shows a schematic diagram for illustrating ATM exchange system to which the present invention is applied; 
     FIG. 2 shows a subscriber control module having test functions according to the present invention; and 
     FIG. 3 is a block diagram of the test apparatus in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The preferred embodiment according to the present invention will now be described in detail in accordance with the accompanying drawings. 
     FIG. 1 is a schematic diagram for illustrating ATM exchange system to which the present invention is applied, the system consisting of a central exchange subsystem  3  and plural local exchange subsystems  1 ,  2 . 
     Local exchange subsystems  1 ,  2  include: subscriber matching modules  11 ,  21  allowing respective subscribers of STM-1 (155 Mbps), DS3 (45 Mbps) and DS1E (2 Mbps) to be connected to the subscriber switching network; STM-1 (155 Mbps) repeater line; repeater line matching modules  12 ,  22  which allow STM-4 (622 Mbps) repeater line to be connected to the subscriber switching network; subscriber switching network modules  13 ,  23  which allow the subscriber matching modules  11 ,  21 , repeater line matching modules  12 ,  22  and subscriber control modules  14 ,  24  to be connected to the connection switching network; and the subscriber control module  14 ,  24  according to the present invention which are responsible for collecting respective warning messages from the modules in the local exchange subsystems and for making maintenance controls and connection of calls. 
     The connections of respective modules and subscriber switching network modules  13 ,  23  are made through the inter module interfaces IMI, wherein the number of the required IMI is varied depending upon the rates of either subscribers or repeaters. 
     The central subsystem  3  allows the local exchange subsystems  1 ,  2  to be connected to each other, and performs general controls of the system. The central subsystem  3  includes a network synchronizing module  31 , the connection switching network module  32  and maintenance control module  33 . 
     The network synchronizing module  31  generates, for the purpose of a synchronizing of an overall exchange network, the clocks for the network synchronization and then supplies inter module timing clocks IMTI and central timing clocks CTSI whose periods are identical to that of IMTI into respective various modules of the subscriber switching network modules  13 ,  23 , connection switching network module  32  and maintenance control module  33 . The connection switching module  32  allows the subscriber switching network modules  12  and  32  to be connected to each other, and is connected to the maintenance control module functioning to perform the maintenance control of the overall exchange system and management thereof. 
     Referring to FIG. 2 showing the subscriber control module according to the present invention, this module includes a cell multiplexing/demultiplexing device  41 , a test device  42 , a warning message collecting device  43  and a call-connecting control device  44 , collects warning messages and controls the maintenance and call-connections. 
     The cell multiplexing/demultiplexing device  41  transports and receives a series data at 187.79 Mbps to and from the subscriber switching network modules  13 ,  23  through the IMI, and further receives from the subscriber switching network module the local timing signals LTSI used for synchronizing clocks of the data. In addition, the cell multiplexing/demultiplexing device  41  multiplexes the incoming cells from the test device  42  and call-connecting control device  44  through the 100 Mbps-rate series TAXI port thereof and then outputs it to the subscriber switching network modules  13 ,  23 . The device  41  demultiplexes the incoming cells from the subscriber switching network modules to output it the test device  42  and TAXI port of the call-connecting control device  44  depending upon the destinations. Further, the device  41  outputs the warning messages of Off_Alm and Fun_Alm, the warning messages being substantially signals of a logical high level, to the warning message collecting device  43 . 
     The warning message collecting device  43  collects the warning messages generated from the respective test device  42 , call-connecting control device  44  and cell multiplexing/demultiplexing device  41 , as well as the warning messages generated from each of the modules in the local exchange subsystem (not illustrated). Then, the collected results under the internal message format are notified to the call-connecting control device  44 . 
     There are provided an internal controlled cell communications between the call-connecting control device  44  and the cell multiplexing/demultiplexing device  41  connected thereto through the TAXI port, and an internal message communication between the call-connecting control device  44  and the warning message collecting device  43  through the EIA- 485  based series port. Also, the call-connecting control device  44  outputs the OFF_Alm and Fun_Alm to the warning message collecting device  43 . 
     Further, the call-connecting control device  44  communicates with the maintenance control module of the central exchange subsystem to control the call connections. 
     FIG. 3 is a block diagram of the test device in accordance with the present invention, the test device includes: a central control circuit portion  101 , an address decoding portion  102 , a memory portion  103 , a cell transmitting control portion  104 , a cell receiving control portion  105 , a test cell generating portion  106 , a test cell analysis portion  107 , a transmission control cell FIFO  108 , a receiving control cell FIFO  109 , a transmitting test cell FIFO  110 , a receiving test cell FIFO  111 , a TAXI transmission portion  112 , a TAXI receiving portion  113 , and a TAXI selection portion  114 . 
     The central control circuit portion  101  substantially comprises such as 32 bit-based processor, which generally controls the test device, supplies the required clocks into the test device and generates and supplies a resetting signal. 
     Address and control signals from the central control circuit portion  101  are forwarded through local busses to the address decoding portion  102  which combines the received signals to designate respective addresses associated with components and resisters in respective portions of the test device. 
     The memory portion  103  coupled to the local buses includes ROM for storing programs and RAMS for storing various types of data. 
     The cell transmitting control portion  104  coupled the local buses controls the transmission of control cells to report the current status of the test device or the route test results under the control of the central control circuit portion  101  to the call-connecting control device, and further controls, based upon the content of the received control cells from the call-connecting control device, the transmission of test cells used for testing the internal routes in the exchange system. 
     The cell receiving control portion  105  is coupled to the local buses to control the receiving of the control cells and test cells in response to the central control circuit portion  101 . 
     The test cell generating portion  106  is coupled to the local buses to actually generate the physical test cells under the control of the cell transmitting control portion  104  to store them in the transmitting test cell FIFO  110 . 
     The test cell analysis portion  107  reads the test cells received from the receiving test cell FIFO  111  to physically analyze the content of the received test cells to deliver the result to the central control circuit portion  101  through the local buses. 
     The transmission control cell FIFO  108  receives through the local buses the control cells which are generated from the central control circuit portion  101  to temporarily store the received cells, and delivers the stored cells to the TAXI transmission portion  112  under the control of the cell transmitting control portion  104 . 
     The receiving control cell FIFO  109  temporarily stores the control cells received from the TAXI receiving portion  113  to then deliver through the local buses them to the central control circuit portion  101  under the control of the cell receiving control portion  105 . 
     The transmitting test cell FIFO  110  temporarily stores the test cells generated from the test cell generating portion  106 , and transports them to the TAXI transmission portion  112  thereafter. 
     The receiving test cell FIFO  111  temporarily stores the test cells generated from the TAXI receiving portion  113 , and transports them to the test cell analysis portion  107  thereafter. 
     The TAXI transmission portion  112  receives in parallel the control cells and test cells, these cells being transported through the TAXI port and cell multiplexing/demultiplexing device and then towards the call-connecting control device, from the transmission control cell FIFO  108  and transmitting test cell FIFO  110 , converts the received cells into the series data and then outputs it to the TAXI port. 
     The TAXI receiving portion  113  converts it into the corresponding parallel data either control or test cells serially received from the TAXI selection portion  114 , and then outputs them to the receiving test cell FIFO  111  or the receiving control cell FIFO  109 . 
     The TAXI selection portion  114  selects the series data output from the TAXI transmission portion  112  during the loopback testing mode, but, otherwise, selects the data from the cell multiplexing/demultiplexing device to transport it to the TAXI receiving portion  113 . 
     It can be seen from the foregoing that the test apparatus thus constructed allows the control cells made for reporting the current status of the test apparatus obtained by receiving the control cells from the call-connecting control device and by analyzing their contents to forward them to the call-connecting control device, or the test apparatus forms the control cells relating to the results obtained by generating the test cells, transporting the cells to the route to be tested, receiving and analyzing the test cells from the route and then outputs the control cells thus produced to the call-connecting control device. 
     While particular embodiment of the present invention has been illustrated and described, it is to be understood that the invention is not limited to the preferred embodiment and that various modifications, changes, and variations will be apparent from the foregoing descriptions without departing from the spirit and scope of the invention. 
     For ATM exchange system, it is possible to, according to the present invention, allow an operator for the exchange system to test overall routes in the subscriber and switching network within the exchange system using the test apparatus placed in the subscriber control module of the respective local exchange subsystem, to test the subscribers at various rates. Further, the present invention provides an easy installation of the test apparatus in the exchange system, and various tests available from the application softwares.