DE19636951A1 - Telecommunication network termination unit - Google Patents

Abstract

A telecommunication network termination unit (100) has a first interface (110) for connecting to the telecommunication network and a second interface (120) for connecting telecommunication transmission devices. The disclosed telecommunication network termination unit is characterised in that a third interface (130, 140) is provided for connecting equipment which is not designed to be directly connected to the second interface.

Description

The present invention relates to telecommunications Network termination unit according to the preamble of the patent Proverb 1, d. H. a telecommunications network termination unit with a first interface for connection to the tele communication network, and a second interface to the Connection of telecommunications terminal equipment.

Such a telecommunication network termination unit is For example, a so-called NT unit (network terms nation unit) of an ISDN telecommunications system. In the usually the NT unit installed at the ISDN subscriber forms the interface between the facilities of the ISDN Operator (switching offices, line network, etc.) and the Facilities of the ISDN subscriber (subscriber lines, Telecommunications terminal equipment such as tele phone, fax etc.).

The NT unit is able to operate from a central office or a so-called LT unit (line termination unit) of the ISDN operator over the same network in ISDN systems as a so-called U interface (U-Inter face) is designed to receive (U-) data visually implement the format and if necessary in son editable way and finally as (S-) data about an S-interface (S-interface) to the ISDN subscriber to spend facilities. Conversely, the same way also data from the ISDN subscriber equipment to the ISDN Operator facilities (and from there to other part participants) are transferred.

A schematic representation to illustrate the situation just described in words is shown in FIG. 3.

The system shown in FIG. 3 consists of an ISDN operator section labeled B (shown on the left) and an ISDN subscriber section labeled T (shown on the right).

The ISDN operator section B includes a switching office 1 , which is closed to the outside by an LT unit 2 . The exchange 1 is connected to the ISDN subscriber section T via a line network (U interface), more precisely to a first interface of an NT unit 3 provided there. The NT unit 3 is connected to up to eight ISDN telecommunication terminals via a second interface through subscriber lines (S interfaces), each designated S. In the example considered, the ISDN telecommunication terminal devices in question are an ISDN telephone 41 and an ISDN facsimile device 42 .

The NT unit 3 contains a shown in Fig. 2 on the left Darge, hereinafter for the sake of simplicity as U-part U-side section 31 and shown in Fig. 3 on the right, hereinafter referred to as S-part for simplicity S-side section 32 . U-side incoming (ie received via a first interface of the NT unit 3 ) (U) data (data packets) are converted into a so-called IOM format by the U part 31 , and the resulting (IOM) data (Data packets) are in turn - if necessary after processing the same in the meantime - converted into an S format by the S part 32 and output via a second interface of the NT unit 3 to the connected ISDN telecommunications terminal equipment. Conversely, incoming (S) data (data packets) received on the S side, ie received via the second interface of the NT unit 3 , are converted into the IOM format by the S part 32 , and the resulting (IOM) data ( Data packets) are in turn - if necessary after processing them in the meantime - converted into U format by U part 31 and output to the ISDN operator devices via the first interface of the NT unit.

From a physical point of view, the NT unit 3 converts the 2-wire U interface to the 4-wire S interface.

As the structure of the NT unit 3 described above already suggests, only specially prepared devices, more precisely only ISDN devices, can be connected to their second interface as telecommunication terminal devices.

If other than ISDN devices, for example until recently only used analog telephones or fax machines are connected to the ISDN unit via the NT unit, this requires the interposition of a so-called terminal adapter between the second interface of the NT Unit 3 and the non-ISDN device.

On the one hand, the terminal adapter carries a digital / analog Conversion or an analog / digital conversion between the Non-ISDN device and the NT unit transferred data through and on the other hand ensures that the non-ISDN device the NT unit and the ISDN operator facilities as one "normal" ISDN device appears. To achieve the last mentioned property of the terminal adapter it is under other particularly required via a so-called D- Channel of the ISDN transmitted and to be transmitted packet and Monitor, evaluate, change signaling data and / or generate new.

Although this should be well known, the full is for the sake of consistency mentioned that in ISDN B channels for use data transmission and D-channels for packet data and signali data transmission are provided and that B-channel Data and D-channel data interleaved or ver  mixes and in along with other tax information units of data packets (data frames) as a data stream via the Line network and the subscriber lines are transmitted. With the so-called ISDN basic connection, it is per subscriber connecting two B channels and one D channel, which are provided and treated in the manner mentioned.

The terminal adapter described above is because of this tasks, some of which are very complex, relatively complicated builds and accordingly prone to failure and expensive.

The present invention is therefore based on the object the telecommunications network termination unit according to the Ober concept of claim 1 to develop such that this simpler connection of non-ISDN devices ISDN enables.

According to the invention, this object is characterized by the solved the part of claim 1 claimed features.

Accordingly, it is provided that at the telecommunications network Termination unit a third interface for connecting not for direct connection to the second interface designed devices is provided.

In the case of an ISDN telecommunications network, this means that an additional interface is provided on the NT unit hen is that for the connection of non-ISDN devices reser is fourth.

On the one hand, this means that at least parts of the previously end of non-ISDN devices to be provided terminal adapters into the telecommunications network termination unit, d. H. in the NT unit can be integrated, and secondly, the over this third cut instead of transferred data the S format to be used for the second interface have a format which corresponds to the format of the data which is about  the first interface of the NT unit can be replaced, So come closer to the U format or at least with less Effort can be implemented or generated from this.

The at least partial integration of the terminal adapter in the NT unit enables the inte Part of the terminal adapter to the actual NT unit and thus ensures trouble-free interaction units, especially if the NT unit and the terminal adapter comes from different manufacturers, sometimes not.

The possibility that data via the third interface can be transferred which have a format that for example like the IOM format in the NT unit with weni effort into the U format convertible or generated from it cash, it allows the processing of the over the third interface exchanged data in the NT unit can be shortened. Apart from that, it can also any external preparation that may still be required or processing the input into the third interface simplify the data output from it.

It became a telecommunications network termination unit found a simple, but at the same time little interference-prone connection of non-ISDN devices to ISDN enables.

Advantageous developments of the invention are the subject of subclaims.

The invention is explained below with reference to exemplary embodiments play explained with reference to the drawing. Show it  

Fig. 1 shows schematically the structure of the message according to the invention communications network termination unit in the form of a recess provided for the ISDN NT unit,

Fig. 2 shows schematically the use of the NT unit 100 shown in Fig. 1 for connecting non-ISDN tele communication terminal equipment to the same, and

Fig. 3 shows schematically the structure of an ISDN system having a conventional NT unit.

The invention will hereinafter be specifically described with reference to FIG Telecommunication network termination that can be used in ISDN systems units, in particular with reference to the introduction NT units already described. The fiction according telecommunication network termination unit can, however also be and is a device other than an NT unit in addition, in principle also in any other, from ISDN telecommunication systems various telecommunication cation systems can be used.

The names used in the description for the individual ISDN or NT unit interfaces are here for common names. Unless nevertheless There should be any doubt as to their respective meaning in particular to the corresponding definitions in the ETSI and ANSI standards. The same applies to the after data (package) named for the respective interfaces Designations.

The interface names used include send generic terms, all of which include sub sumable interface versions may include. So are just a few examples, including the Uk and Uk0 interfaces through the general generic term U interface, the S0 interface through the general  General term S-interface and the IOM-2 interface through includes the general generic term IOM interface. Ent speaking here also applies to those according to the respective Interfaces named data (package) format names.

The basic structure of the telecommunication network termination unit according to the invention will now be explained with reference to a NT unit shown schematically in FIG. 1.

The NT unit shown in FIG. 1 is identified there with the reference number 100 . It has a first interface 110 , a second interface 120 and a third interface 130 , 140 as connection options (interfaces) that are common from the outside, the third interface being composed of a control data interface 130 and a user data interface 140 .

The first interface 110 is used for connection to a U-interface of the ISDN system, the second interface 120 for connecting ISDN telecommunication terminal devices, and the third interface 130 , 140 for connecting non-ISDN telecommunication terminal devices such as analog telephones or Fax machines.

The first interface 110 is with a first data stream conversion unit in the form of a U part 150 of the NT unit 100 , the second interface 120 with a second data stream conversion unit in the form of an S part 160 of the NT unit 100 , and the third interface 130 , 140 connected to the S-part 160 , a D-channel control unit 180 , and an IOM line 170 connecting the U-part 150 and the S-part 160 .

The U part 150 of the NT unit 100 according to the invention corresponds essentially to the U part 31 of the conventional NT unit 3 , the S part 160 the S part 32 and the IOM line 170 of the connection designated IOM between the U part 31 and S part 32 .

In the example described, the IOM line 170 , as its name already suggests, is transferred to pointing data or data formats via the IOM line 170 . This is always assumed in the following explanations. Nevertheless, there is no restriction to this. In principle, the data or data packets transferred via the IOM line 170 (which are introduced through the U part 150 , the S part 160 and the third interface 130 , 140 ) can also have any other format.

The control of the S-part 160 via the control data interface 130 serves primarily for its activation and deactivation and for a fair distribution (arbitration) of the access rights to the D channel explained in more detail later.

The D-channel control unit 180, which is not present in conventional NT units, is a so-called HDLC controller and, as the name suggests, has the function of monitoring, evaluating and / or changing data transmitted via the D-channel of the ISDN and / or to generate and feed data to be transmitted via the D channel. The D-channel control unit 180 accesses the D-channel via a connection to the IOM line 170 .

The D-channel control unit 180 can at least partially assume the tasks that an adaptation logic (terminal adapter) must perform in order to be able to connect a non-ISDN device as or as an ISDN telecommunications terminal to the ISDN; it is in particular depending on the type and the number of non-ISDN equipment, the location on the third section 130, 140 of the NT unit are connected, controlled by the control data interface 130th

The user data exchange between the non-ISDN devices and the NT unit takes place via the user data interface 140 . The user data interface 140 is connected to the IOM line 170 via a PCM line (not shown in FIG. 1); in the example considered, it is an IOM-like PCM interface.

Via the control data interface 130 and the user data interface 140 , as will be explained in more detail later with reference to FIG. 2, non-ISDN devices can be connected as or as ISDN telecommunication terminal devices.

The connection of telecommunications terminals via a different than the second or S interface 120 of the NT unit 100 makes it necessary to ensure that none of the up to eight connected to the second or S interface 120 ISDN devices and in addition, none of the non-ISDN devices connected via the third interface 130 , 140 is permanently denied access to the (single) D channel. For this purpose, in the example under consideration, an arbitration mechanism present on the S interface is acted upon, which ensures that none of the eight telecommunication terminals connectable to the second or S interface is permanently denied access to the D channel . The said action on the arbitration mechanism of the S interface is carried out by an external control via the control data interface 130 . Access to the existing arbitration mechanism provided on the S interface takes place via the S part 160 , which, in deviation from the S part, provides conventional intervention options.

The connection of non-ISDN devices to the third interface 130 , 140 of the previously explained NT unit 100 will now be described with reference to FIG. 2.

. The NT unit 100 shown in Figure 2 is described above with reference to Figures 1 NT unit 100. Identical reference symbols in FIGS. 1 and 2 denote identical elements.

In the example considered, the non-ISDN devices which are to be connected to the ISDN via the NT unit 100 are conventional analog telephones, for which so-called a / b connections are to be provided. In FIG. 2, two shown designated the reference numerals 211 and 221 a / b connections. However, it should be pointed out at this point that the number of devices that can be connected to the ISDN via the third interface 130 , 140 of the NT unit 100 can in principle be as high as desired.

The a / b connections 211 and 221 are input / output connections of so-called SLICs 210 and 220 . SLICs (subscriber line interface circuits) are (subscriber line interface) circuits which are provided in particular for signal level adaptation and amplification (analog telephones sometimes work with voltages of several tens of volts) and for counting pulse processing.

The SLICs 210 and 220 are connected to an adaptation unit 200 , which in turn is connected to the user data interface 140 , the control data interface 130 and a system control unit 300 .

The adaptation unit 200 , since essential parts of the logic to be provided for connecting non-ISDN devices to the ISDN adaptation logic are already accommodated in the NT unit 100 , more precisely in particular in the D-channel control unit 180 , can be constructed relatively simply. In the example under consideration, the adaptation unit 200 is implemented by a so-called CODEC filter, which does nothing other than convert analog signals into a digital pulse sequence according to a standardized method (coding process) and vice versa (decoding process).

The signals coded by the adaptation unit 200 are sent via the user data interface 140 of the NT unit 100 directly to the IOM line 170 , where they are fed into one of the B channels of the data stream transmitted thereover. Conversely, data received from the B channels - insofar as it is intended for the non-ISDN devices - is decoded by the adaptation unit 200 and output to the non-ISDN devices via the downstream SLICs.

Depending on the practical implementation of the adaptation unit 200 , this and / or the downstream SLICs require various controls.

The adaptation unit 200 and / or the SLICS 210 , 220 are controlled via the system control unit 300 , which in the example under consideration may be implemented by a microprocessor, microcontroller or the like.

The said system control unit 300 not only controls the adaptation unit 200 and / or the SLICs 210 , 220 , but also (via the control data interface 130 ) the NT unit 100 . The control data interface 130 and the D-channel control unit 180 are combined in FIG. 2 to form a common NT control unit 190 .

Depending on the practical implementation of the adaptation unit 200 , as shown below with the aid of a few examples, there can be varied variations in the structure and / or in the control of the same and / or the downstream SLICs 210 , 220 .

The examples described below have in common that the adaptation unit 200 is implemented by one or more CODEC filters.

The adaptation unit 200 shown in FIG. 2, which can be implemented, for example, by the Siemens component PEB 2466 (SICOFI4-.mu.C), is designed for connecting four analog telecommunication terminal devices and is controlled as described with reference to FIG .

Alternatively, the adaptation unit 200 can be implemented by one or more Siemens components PEB 2161 (ARCOFI-BA) connected in parallel, to which, in contrast to the illustration in FIG. 2, only one in each case, additionally connected to the system control unit 300 SLIC is connectable.

Instead of the Siemens PEB 2161 (ARCOFI-BA) modules, so-called standard CODECs can also be used. In this case, however, so-called frame strobe signals must also be provided to identify the active time slots. A frame strobe signal must be generated for each non-ISDN device and forwarded to the corresponding CODEC filter. Such frame strobe signals are preferably generated by the D-channel control unit 180 or the NT control unit 190 .

The above-described NT unit 100 designed according to the invention can be used not only as a telecommunications network termination unit, but also as an interface that can be connected to various types of telecommunications network termination units for connecting a computer or the like to the ISDN.

This, in conventional NT units not given ver usability can be achieved by the provision of the third interface for the connection of telecommunications end devices and also by the provision of several operating modes in which the NT unit is selectively via the control data interface 130 depending on the application is relocatable.

In the first of said modes of operation is the one described NT unit as the tele described in detail above communication network termination unit can be used.

In the second of the said operating modes, it can be used as Interface for connecting a computer or the like via various types of telecommunications network termination unit can be used on the ISDN.

The connection of the NT unit used as a computer interface to the ISDN takes place either selectively or simultaneously via the first interface 110 and the second interface 120 thereof , the connection 110 for connection to a U-interface of the ISDN and the connection 120 for connection to an S interface of the ISDN, that is, to an NT unit or the like.

The connection of the NT unit used as the computer interface to the computer to be connected to the ISDN like a telecommunication terminal is carried out via the third interface 130 , regardless of whether the connection to the ISDN has to be made via a U interface or via an S interface. 140 of the NT unit 100 .

Via the user data interface 140 , the user data are exchanged between the ISDN and the connected device, which may be a computer in the example considered; Via the control data interface 130 , the NT unit is put into a state which enables the NT unit 100 to be connected to a telecommunications network termination unit of the ISDN like a telecommunication terminal. The technical requirements that a device must meet in order to be properly connected to the ISDN as a telecommunications terminal are known and do not require any further explanation here.

It can prove to be advantageous if the U part 150 and / or the S part 160 are designed such that they can be selectively activated and deactivated via the control data interface 130 .

In said second operating mode of the NT unit according to the invention, IOM data output (to be sent) by the computer 200 is input by the computer 200 via the user data interface 140 into the NT unit 100 , there via the said PCM line into the IOM line 170 fed in, forwarded via this to the U part 150 and / or to the S part 160 , converted there into U and / or S data and via the first interface 110 (in the case of U data) and / or the second Interface 120 (in the case of S data) output. Be reversed

• U data received via the first interface 110 are converted into the IOM format by the U part 150 , output to the IOM line 170 and from there via the PCM line and the user data interface 140 to the computer 200 forwarded, and / or
• S data received via the second interface 120 are converted into the IOM format by the S part 160 , output to the IOM line 170 and from there via the PCM line and the user data interface 140 to the computer 200 forwarded.

The NT unit described is preferably one integrated chip. Such a 1-chip NT unit is on the one hand extremely versatile and flexible, and on the other hand very easy to handle and (due to the ideal coordination of the individual chip components) can be operated without problems.

Claims (12)

1. Telecommunications network termination unit ( 100 ) with a first interface ( 110 ) for connecting to the telecommunications network, and a second interface ( 120 ) for connecting telecommunications terminals, characterized by a third interface ( 130 , 140 ) for connecting not to the immediate Connection to devices designed for the second interface. 2. Telecommunication network termination unit according to claim 1, characterized in that via the first interface ( 110 ) a first data stream format data streams, via the second interface ( 120 ) a third data stream format data streams, and via the third interface ( 130 , 140 ) data streams having a second data stream format are interchangeable. 3. Telecommunication network termination unit according to claim 1 or 2, characterized in that it has two series-connected data stream conversion units ( 150 , 160 ) through which a data stream having a first format into a data stream having a second format and this into a third A data stream having a format or a data format having a third format can be converted into a data stream having a second format and this can be converted into a data stream having a first format. 4. Telecommunications network termination unit according to one of the preceding claims, characterized in that in this at least parts of a terminal adapter are inte grated, which is designed for connecting a non-direct connection to the second interface ( 120 ) telecommunications terminal to the second interface between the second interface and the telecommunications end device would be provided. 5. Telecommunications network termination unit according to one of the preceding claims, characterized in that the third interface ( 130 , 140 ) consists of a control data interface ( 130 ) and a user data interface ( 140 ). 6. Telecommunications network termination unit according to one of the previous claims, characterized, that this is an NT unit of an ISDN system. 7. Telecommunications network termination unit according to claim 6, characterized in that the control data interface ( 130 ) is designed such that control data are interchangeable, which the monitoring, evaluation, change and / or generation of transferred via a D-channel or packet and signaling data to be transferred and the distribution of access rights to the D channel among the telecommunications network termination unit connected to telecommunications terminal equipment. 8. Telecommunications network termination unit according to claim 7, characterized in that a D-channel control unit ( 180 ) in for monitoring, evaluation, modification and / or generation of packets and signaling data transferred or to be transferred via the D-channel the telecommunications network termination unit is provided. 9. Telecommunications network termination unit according to claim 8, characterized in that the D-channel control unit ( 180 ) at a point between the first data stream conversion unit ( 150 ) and the second data stream conversion unit ( 160 ) has access to the D-channel. 10. Telecommunications network termination unit according to one of claims 6 to 9, characterized in that the user data interface at a point between the first data stream conversion unit ( 150 ) and the second data stream conversion unit ( 160 ) on the location provided for the user data transmission in the telecommunications network Has access. 11. Telecommunications network termination unit according to one of claims 6 to 10, characterized in that the user data interface ( 140 ) is designed as an IOM-like PCM interface to which the telecommunications terminal equipment to be connected can be connected with the interposition of a CODEC filter. 12. Telecommunications network termination unit according to one of the previous claims, characterized, that it is designed so that it as or as a Telecommunication terminal to various types of tele Communication network termination units can be connected.