Control system for a digital telephone exchange.

p0001The invention relates to a control system for a digital telecommunication exchange to control the connection establishment and the disconnect between subscriber stations and / or switching systems and to monitor the connection by analyzing digital signs that are exchanged between the subscriber stations and / or switching systems and control means at least one signaling channel.

p0002Such known control systems are equipped to evaluate the digital characters with at least one digital computer. Due to the rapid development of digital telecommunications switching systems, it is possible to include a variety of monitoring functions for the telecommunication network in such a control system. Thus, received characters are checked for distorted during transmission, plausibility and noise immunity. It is also possible to check individual transmission sections of the telecommunication network for proper operation. The various monitoring functions and the functions of the connection setup and the disconnect are standardized and defined in signaling protocols. Such signaling protocols are described for example in the FTZ guidelines 141R50 and 141R60. Through the continuous monitoring of the compounds it is possible to detect faulty connections early on and to cause a restoring the functional safe state. Another possibility is to avoid a deteriorated compounds by, for example, the control means selects other transmission paths for the desired compound.

p0003To perform the computational procedures for monitoring computing time and memory required. This leads to the problem that the digital computer is heavily loaded and quickly reached its capacity, so that only a limited number of signaling channels and thus a limited number of connections to subscriber stations or other switching equipment is allowed. Due to the rapid increase of terminals in the telecommunication network a frequent changeovers of the digital computer to a larger computing capacity is required, whereby the efficiency of the control system is reduced.

p0004The object of the invention to provide a control system that allows the placement and monitoring of large numbers of compounds by digital sign without the computational capacity of the digital computer must be increased.

p0005This object is achieved for a control system of the initially mentioned type in that the control means are connected upstream to programmatically monitor multiple connection properties Vorverarbeitungsbausteine ​​that the connection state proposed to the controller messages in question.

p0006By the invention, the controller of computationally complex monitoring tasks is relieved. These will now be taken over automatically, regardless of the controller of the Vorverarbeitungsbausteinen. The Vorverarbeitungsbausteine ​​give off only in case of malfunction or other critical connection states relating to the controller, which then may take appropriate measures to establish a connection or disconnection. For this purpose, less processing capacity of the digital computer is stressed, so that more processing capacity can be provided for the switching of connections, that is, the switching power is higher. If the telecommunication exchange is to be extended, so more Vorverarbeitungsbausteine ​​are provided only for the connection of corresponding signaling channels. An additional expansion of computing capacity is not necessary, whereby a high efficiency of the control system is given. The Vorverarbeitungsbausteine ​​work programmatically. This means that in case of change of the signaling protocol or additional monitoring tasks only the program is to change. As a result, the control system can be flexibly adapted to various fixed in signaling protocols placement and monitoring functions.

p0007The loading of the program is controlled in an advantageous development of the invention by the control device. This makes it possible to modify the workflow of Vorverarbeitungsbausteins, which is defined in the program. The program can be retrieved from a mass storage, to which the control device has access. This enables a very fast and convenient loading of the program is possible.

p0008In another development of the invention provides that in Zeichengebekänalen with different signaling protocols for each signaling protocol one program is provided, which is executed, depending on the signaling protocol used.

p0009It is thereby achieved that the Vorverarbeitungsbausteine ​​are adjustable to different signaling protocols in a simple manner.

p0010It makes sense to continue if more Vorverarbeitungsbausteine ​​are combined to form a signaling device which is controlled by a microprocessor. Thus, the circuit complexity is further reduced.

p0011A preferred embodiment of the invention further provides that at several connected to a signaling device signaling channels each signaling channel a predetermined period of time is associated in a fixed time frame, are in the processed or forwarded to the control device the characters. By these measures, a signaling module mark multiple signaling channels evaluate different times. For this purpose, it is expedient to buffer the character of each signaling channel in a line driver block, until the signaling channel to the assigned time section in the time frame in which the evaluation of the sign is made achieved. By caching the mark stochastic and cyclically occurring can be reliably detected and passed without distortion on the signaling module.

p0012If the predetermined period of time used for charging, charging during operation is possible without interfering with the other channels.

p0013An embodiment of the invention will be explained below with reference to the drawing. It shows<ul><li>Fig. 1 shows the structure of a digital telecommunications network, in a schematic representation,</li><li>FIG. 2 shows the basic structure of a telecommunications switching system in a block diagram,</li><li>3 shows a control system with a control device, to which a plurality Vorverarbeitungsbausteine ​​are connected,</li><li>4 shows the structure of a signaling device, which analyzes the characters of several signaling channels, and</li><li>Fig. 5, the time interleaving of the evaluation of the character of several signaling channels by a Vorverarbeitungsbaustein.</li></ul>

p0014In Fig. The structure of a digital telecommunication network, including telecommunication network is called, shown schematically. The telecommunications network is hierarchically divided into different network levels 1 to n. The network layer 1 is formed of subscriber stations 4 to 9. These are connected to telecommunications switching systems 10 and 11, which form the network level. 2 The next higher level 3 consists of telecommunications switching systems, one of which telecommunication exchange 12 is shown to which the telecommunication exchanges 10 and 11 are connected.

p0015The star-shaped structure in several levels until the level n as long continued until all subscriber stations of a regional, national or international telecommunications network can be connected via switching systems each other.

p0016In order to exchange information in the form of voice or data, for example, between the subscriber stations 6 and 8, four transfer sections 14, 16, 18, 20 and three telecommunication exchanges are to go through. To select the correct transmission sections need the telecommunication exchanges 10, il, 12 control information, so-called character, which are transferred to the transfer sections 14, 16, 18, 20, along with serving as information carriers useful signals to a multiplexing method. The characters include dialing information that causes the switching through a connection to the desired subscriber station 6, 8, and other information to establish a connection, disconnection, and to monitor the connection, such as acknowledgment signals, test signals, Initialisierunggsinformationen and information about the construction and dismantling of the signaling connection. The meanings of the individual characters are set in a signaling protocol or a character list. Depending on the used communication network, such as telephony or broadband network, as well as on the type of telecommunications switching equipment of the subscriber stations or other central network facilities are of a telecommunication exchange mark evaluate with different signaling protocols.

p0017In Fig. 2, the basic structure of the digital telecommunication switching system 11 is shown. This is connected to the subscriber station 8 via the transmission section 20 and the parent telephone exchange 12 through the transmission section 18 and the subscriber stations 7 and 9. FIG. In addition to these connections, a variety of other connections to subscriber stations or telecommunications switching systems exists which are not shown for clarity.

p0018Transmission lines of the subscriber stations 7, 8, 9 and the transmission section 18 of the telephone exchange 12 are connected to multiplexer demultiplexer blocks 30, 32, 34, 36th These divide the incoming signals into useful signals, for example, voice or data, and in character. The useful signals are a switch fabric 48 supplied via lines 40, 42, 44, 46, which forwards the useful signals in a known manner in the desired direction.

p0019The characters are supplied via signaling channels 50, 52, 54, 56 a Vorverarbeitungsbaustein 60th In practice 60 more Vorverarbeitungsbausteine ​​are provided according to the number of instructional of the telecommunication exchange connections in addition to Vorverarbeitungsbaustein that have been omitted in FIG. 2 for reasons of clarity. The multiplexer-demultiplexer devices 30, 32, 34, 36 operate bidirectionally, ie the outgoing of the telecommunication exchange useful signals and signs are reassembled by multiplexing after Zeitverschachtelungsprinzip a signal and or via one transmission channel to the subscriber stations 7, 8, 9 sent. to the telecommunications switching system 12. The Vorverarbeitungsbaustein 60 is connected to a controller 62 and exchanges data with this data. The control means 62 forms together with several Vorverarbeitungsbausteinen on the type of Vorverarbeitungsbausteins 60, a control system 64, which will be explained in more detail in connection with Fig. 3 below.

p0020The control device 62 is connected via a control line 74 to the switching matrix 48 and via a data bus 66 with a plurality of Vorverarbeitungsbausteinen 60a, 60b, 60c, 60d. At these respective multiple signaling channels are connected, for example, to the Vorverarbeitungsbaustein 60a signaling channels 50, 52, 54 and on the 60d Vorverarbeitungsbaustein the signaling channels K1 to K8.

p0021The controller 62 includes a digital computer, which is connected via an input / output channel and a conduit 68 with a system terminal 70 and a mass storage 72nd The system terminal 70 has an input keyboard, which invite operator programs for the control unit 62, start and stop, or may act through other input commands controlling to the control system 64th

p0022Technical details of the Vorverarbeitungsbausteins 60d are shown in Fig. 4 in a block diagram. To a data and address bus 80, a microprocessor 82, a read only memory 84, a RAM 86, a timer 88, a bus driver 90 and four line driver blocks 92, 94, 96, 98 are connected. The latter are each connected to two line matching circuits 100 to 114 are connected to the eight signaling channels K1-K8. The bus driver 90 forms the interface between the data and address bus 80 of the Vorverarbeitungsbausteins 60d and the data bus 66 of the control system 64 and is used for data transfer between the latter and the control unit 62nd

p0023The operation of the control system 64 will now be explained with reference to FIGS. 3 and 4. Under control of the control unit 62 and the microprocessor 82 is via the data bus 66, the bus driver 90 as well as the data and address bus 80 loads a program A or B in the main memory 86 for a yet to be described data transfer method. The microprocessor 82 uses this a Urladerprogramms C, which is stored in ROM 84th

p0024The character of the mark channels K1 to K8 get over the line matching circuits 100 to 114 at the line driver blocks 92 to 98, which latch mark in a memory. The program A or B is started by a control command of the control unit 62, and the stored character are read at predetermined intervals in the memory 86 during the Abarbeitens the program according to the principle of interleaving and evaluated. Programs A and. B are adapted to the particular signaling protocol of the individual signaling channels K1 to K8 incoming and outgoing character, so that the characters assigned functions can be executed properly. Characters that control the connection and disconnection, such as characters with dialing information, with availability information or triggering information are forwarded via the address and data bus 80, the bus driver 90 and the data bus 66 to the control device 62nd The measures necessary for monitoring of transmission sections and to establish connections for the transmission mark characters such as handshaking signals, assignment acknowledgment, triggering receipt etc. are independently evaluated by the microprocessor 82nd In this evaluation, new characters are generated in accordance with the signaling protocol and sent via the line driver blocks 92 to 98 and the line matching circuits 100 to 114 via the signaling channels K1 to K8 by the Vorverarbeitungsbaustein. The characters generated by the controller 62 as data transmitted to the Vorverarbeitungsbaustein 60d and also emitted by this as a sign on the signaling channels K1 to K8 to subsequent subscriber stations or telecommunications switching systems.

p0025As an example of the operation of Vorverarbeitungsbausteins 60d monitoring of transmission sections by acknowledgment signals should be examined more closely. For this purpose, a life signal is sent in regular intervals from one end of the transfer section, which passes through the transmission portion and is answered at its other end within a predetermined time with a corresponding life signal. The permanent monitoring of these survival signals is performed by the microprocessor 82 with the support of the timer 88th The life signals between telecommunication exchanges or between a telephone exchange and a subscriber station be replaced when no useful information is transmitted to the monitored transmission portion, so as to detect a faulty connection prior to the transmission of useful signals. It is easy to see that for the monitoring of many transmission sections, a considerable amount of computing time is spend. By shifting the computational effort towards the Vorverarbeitungsbausteinen 60a to 60d, the controller 62 is less stressed, so that they can fulfill their actual purpose of the switching of connections even when a large number of connections without the need to dispense with supervision measures.

p0026Receives the Vorverarbeitungsbaustein 60d from the other side of the transfer section no longer live signals it sends a so-called in repeat procedures or more life signals. If the Vorverarbeitungsbaustein 60d and realize that on the monitored transmission section is a fault, a message is delivered to the controller 62nd The controller 62 may then terminate the faulty connection or establish a new connection path undisturbed.

p0027The Vorverarbeitungsbausteine ​​60a to 60d are designed as plug-in card modules. In the expansion of existing telecommunication exchanges to further compounds many additional Vorverarbeitungsbausteine ​​with existing terminals are connected to corresponding slots, which the additional signaling channels are supplied. This simple measure, the total capacity of the control system and thus increases the efficiency of the telecommunication exchange can be increased.

p0028The control system is also able to process characters with different types of signaling protocols, which are used by various subscriber stations or telecommunication exchanges. this is for each signaling protocol one program, for example, provided the program A or B, which is dependent on demand loading of the controller 62 in the memory 86th The loading of the various signaling protocols associated programs is generated either manually by an operator via the control keyboard of the system terminal 70 or by evaluation of operating conditions that indicate a program or sequence errors caused (watchdog principle). This can be done during operation of the plant.

p0029As already mentioned, carried the traffic between the Vorverarbeitungsbaustein 60d and the control device 62 and the evaluation of the character of the signaling channels K1 to K8 on the principle of time interleaving. In FIG. 5, this interleaving is shown over the time t in a diagram. The names 0 and 1 mean on the ordinate of the diagram that mark the signaling channels K1 to K8 evaluated at certain intervals t1 to t8 or not evaluated. Each of the periods t1 to t8 are controlled by the timer 88th Between the individual time periods t1 to t8 time periods T are provided, in which a data exchange between the control unit 62 and the Vorverarbeitungsbaustein 60d is carried out, for example, to transmit messages and control signals. The sum of each of the periods T and T1 to T8 results in a fixed time frame 120, which is repeated cyclically.

p0030If during operation a new program to be loaded, for example because the signaling protocol of a signaling channel has changed K1 to K8, so to load the time portion of the signaling channel concerned is used. If, for example the signaling channel K4 a new program to be assigned, the controller 62 caused by a control command terminating the currently running in period t4 program. A new program is then loaded and started after the end of charging in this period of time t4. The shop can extend over several time frames 120th the operation of Vorverarbeitungsbausteins 60d is only slightly affected, since the evaluation of the character of the remaining signaling channels will not be interrupted by this procedure.