WO1998011758A1

WO1998011758A1 - Telecommunication network termination unit

Info

Publication number: WO1998011758A1
Application number: PCT/DE1997/001907
Authority: WO
Inventors: Michael Alger-Meunier; Yousif Ammar; Dieter Schmidtlein; Stephan Dosch
Original assignee: Siemens Aktiengesellschaft
Priority date: 1996-09-11
Filing date: 1997-09-01
Publication date: 1998-03-19
Also published as: DE19636951A1

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

description

Telecommunication network termination unit

The present invention relates to a telecommunications network termination unit according to the preamble of claim 1, i.e. a telecommunications network termination unit with a first interface for connecting to the telecommunications network, and a second interface for connecting telecommunications terminals.

Such a telecommunication network termination unit is, for example, a so-called NT unit (network termination unit) of an ISDN telecommunication system. The NT unit, which is usually still installed at the ISDN subscriber, forms the interface between the facilities of the ISDN operator (exchange offices, line network, etc.) and the facilities of the ISDN subscriber (subscriber lines, telecommunications terminal equipment such as telephones, faxes, etc.) .).

The NT unit is capable of communicating with a central office or a so-called LT unit (line termination unit) of the ISDN operator via the same line network, which in ISDN systems acts as a so-called U interface (U interface) ) is designed to receive (U-) data, convert it with regard to the format and, if necessary, process it in some other way, and finally set it up as (S-) data via an S-interface (S-interface) to the ISDN subscribers to spend. Conversely, data can also be transmitted in the same way from the ISDN subscriber equipment to the ISDN operator equipment (and from there to other subscribers).

FIG. 3 shows a schematic illustration to illustrate the situation just described in words. 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 switching office 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 terminal devices via a second interface by means of subscriber lines (S interfaces), each designated S. The said

In the example under consideration, ISDN telecommunication terminal devices are an ISDN telephone 41 and an ISDN facsimile device 42.

The NT unit 3 contains a U-side section 31 shown on the left in FIG. 2, hereinafter referred to as U part for the sake of simplicity, and an S section shown on the right in FIG. 3, hereinafter referred to as S part for simplicity. Section 32. U-side data (data packets) arriving on the U-side, ie received via a first interface of the NT unit 3, 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 them in the meantime - converted into an S format by the S part 32 and output to the connected ISDN telecommunications terminal equipment via a second interface of the NT unit 3. 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 - by the U part 31 converted into the U format and output via the first interface of the NT unit to the ISDN operator facilities.

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 its second interface as telecommunication terminal devices.

If other than ISDN devices, for example until recently only used analog telephones or fax machines should be 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.

The terminal adapter performs on the one hand a digital / analog conversion or an analog / digital conversion of the data transferred between the non-ISDN device and the NT unit and on the other hand ensures that the non-ISDN device of the NT -Unit and the ISDN operator equipment appears like a "normal" ISDN device. To achieve the last-mentioned property of the terminal adapter, it is particularly necessary, among other things, to monitor, evaluate, change and / or generate new packet and signaling data transmitted or to be transmitted via a so-called D channel of the ISDN.

Although this should be generally known, it should be mentioned for the sake of completeness that the ISDN provides B channels for useful data transmission and D channels for packet data and signaling data transmission, and that B channel data and D channel data nested with one another and mixed together with other control information in a ^¬ units of data packets (data frame) as a data stream via the line network and the subscriber lines is transferred. With the so-called ISDN basic access, there are two B channels and one D channel for each subscriber connection, which are provided and treated in the manner mentioned.

The terminal adapter described above has a relatively complicated structure due to its sometimes very complex tasks and is therefore prone to failure and expensive.

The present invention is therefore based on the object of developing the telecommunications network termination unit in accordance with the preamble of claim 1 in such a way that it enables a simpler connection of non-ISDN devices to the ISDN.

This object is achieved by the features claimed in the characterizing part of patent claim 1.

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

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

As a result, at least parts of the terminal adapter previously provided for connecting non-ISDN devices can be integrated into the telecommunications network termination unit, ie into the NT unit, and on the other hand, the data transferred via this third interface can be replaced quickly instead of in the case of second interface to be used S-format have a format that corresponds to the format of the data which the first interface of the NT unit can be exchanged, that is, come closer to the U format or can be converted into or generated from it with less effort.

The at least partial integration of the terminal adapter in the NT unit enables an optimal adaptation of the integrated terminal adapter part to the actual NT unit and thereby ensures a trouble-free interaction of these units, particularly when the NT unit and the terminal adapter comes from different manufacturers, sometimes not.

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

A telecommunication network termination unit was therefore found which enables a simple, but at the same time less interference-prone connection of non-ISDN devices to the ISDN.

Advantageous developments of the invention are the subject of the dependent claims.

The invention is explained in more detail below on the basis of exemplary embodiments with reference to the drawing. Show it 1 schematically shows the structure of the telecommunications network termination unit according to the invention in the form of an NT unit provided for the ISDN,

FIG. 2 shows schematically the use of the NT unit 100 shown in FIG. 1 for connecting Ni'cht ISDN telecommunications terminal equipment to the same, and

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

The invention is described below specifically with reference to telecommunication network termination units which can be used in ISDN systems, in particular with reference to the NT units already explained at the beginning. However, the telecommunication network terminal unit according to the invention can also be a device other than an NT unit and can also be used in principle in any other telecommunication system other than ISDN telecommunication systems.

The designations used in the description for the individual ISDN or NT unit interfaces are the designations used in each case. Unless nevertheless

If there are any doubts about their respective meaning, please refer in particular to the corresponding definitions in the ETSI and ANSI standards. The same applies to the data (package) format names named for the respective interfaces.

The interface names used represent comprehensive generic terms, each of which may encompass all of the interface designs that can be subsumed below. So to name just a few examples, among other things, the Uk and UkO interfaces through the general umbrella term U interface, the SO interface through the general The generic term S-interface and the IOM-2 interface are encompassed by the general generic term IOM interface. The same applies here too for the data (package) format designations named after the respective interfaces.

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

The NT unit shown in FIG. 1 is identified there by reference number 100. As externally accessible connection options (interfaces), it has a first interface 110, a second interface 120 and a third interface 130, 140, 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 has a first data stream conversion unit in the form of a U part 150 of the NT unit 100, the second interface 120 has 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 with 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 essentially corresponds to the U part 31 of the conventional NT unit 3, the S part 160 to the S part 32 and the IOM line 170 of the connection designated IOM between the U part 31 and the S part 32.

In the example described, data or data formats having the IOM format are transferred via the IOM line 170, as their name already suggests. This is always assumed in the following explanations. Nevertheless, there is no restriction to this. Basically, those transferred via the IOM line 170 can. (which are introduced through the U-part 150, the S-part 160 and the third interface 130, 140) data or data packets 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, which will be 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 data to be transmitted via the D channel and to feed it into it. The

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 take on the tasks that an adaptation logic (terminal adapter) has to fulfill in order to be able to connect a non-ISDN device as or as an ISDN telecommunication terminal to the ISDN; it is controlled via the control data interface 130, in particular as a function of the type and number of non-ISDN devices that are connected to the third interface 130, 140 of the NT unit. 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.

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

The connection of telecommunication 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 ISDN devices connected to the second or S-interface 120 and additionally 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 telecommunications terminal devices 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 takes place by an external control via the control data interface 130. The existing arbitration mechanism provided on the S-interface is accessed via the S-part 160, which deviates from the S- Part of conventional NT units offers appropriate intervention options.

Referring now to FIG. 2, the connection of

Non-ISDN devices to the third interface 130, 140 of the previously explained NT unit 100 are described. The NT unit 100 shown in FIG. 2 is the NT unit 100 previously described with reference to FIG. 1; identical reference symbols in FIGS. 1 and 2 designate identical elements.

The non-ISDN devices that are to be connected to the ISDN via the NT unit 100 are, in the example considered, conventional analog telephones, for whose connection so-called a / b connections are to be provided. FIG. 2 shows two a / b connections, designated by reference numerals 211 and 221. 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 interfaces) circuits which are used in particular for signal level adaptation and amplification (analog telephones sometimes work with several ten volt high voltages) 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 can be of relatively simple construction since essential parts of the adaptation logic to be provided for connecting non-ISDN devices to the ISDN are already accommodated in the NT unit 100, more precisely in particular in the D-channel control unit 180. In the example under consideration, the adaptation unit 200 is implemented by a so-called CODEC filter, which does nothing else than convert analog signals into a implement digital pulse train (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 different types of control.

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.

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 shown in FIG 2 combined into a common NT control unit 190.

Depending on the practical implementation of the adaptation unit 200, as will be 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-μC), is designed to connect four analog telecommunication terminal devices and is controlled as described with reference to FIG. 2.

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

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. One frame strobe signal must be generated for each non-ISDN device and sent to the corresponding one

Pass on CODEC filters. Such frame strobe signals are preferably generated by the D-channel control unit 180 or the NT control unit 190.

The NT described above, designed according to the invention

Unit 100 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 different usability, which is not given in conventional NT units, is due to the provision of the third interface for the connection of telecommunications terminal equipment and also by the provision of several

Operating modes reachable in which the NT unit via the Control data interface 130 is selectively relocatable depending on the application.

In the first of said modes of operation, the described NT unit can be used as the telecommunication network termination unit described in detail above.

In the second of said operating modes, it can be used as an interface for connecting a computer or the like to the ISDN via various types of telecommunication network termination units.

The NT unit used as the computer interface is connected to the ISDN either selectively or simultaneously via its first interface 110 and its second interface 120, the connection 110 for connection to a U-interface of the ISDN and the connection 120 is designed 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 telecommunications 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.

As usual, the user data are exchanged between the ISDN and the connected device, which may be a computer in the example under consideration, via the user data interface 140; 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 a telecommunications terminal Being able to be properly connected to the ISDN 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 integrated into a single chip. Such an 1-chip NT unit is extremely versatile and flexible to use, on the one hand, and very easy to use and (due to the ideal coordination of the individual chip components with one another) can be operated without problems.

Claims

claims

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 terminal equipment, characterized by a third interface (130, 140) for connecting not for direct connection 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. Telecommunications network termination unit according to claim 1 or 2, characterized in that these two series-connected Datenεtromkonvertierungε- units (150, 160) aufweiεt, through which a first format data stream in a second format data stream and this in a third Format data stream or a third format data stream into a second format data stream and this can be converted into a first format data stream.

4. Telecommunication network termination unit according to one of the preceding claims, characterized in that at least parts of a terminal adapter are integrated into it, which, when connecting one not designed for direct connection to the second interface (120) Telecommunications terminal device to the second interface between the second interface and the telecommunications terminal device would be provided.

5. Telecommunications network termination unit according to one of the preceding claims, 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 preceding claims, d a d u r c h g e k e n n z e i c h n e t 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 Transferring packet and signaling data and the distribution of access rights to the D channel among the telecommunications terminal devices connected to the telecommunications network termination unit.

8. Telecommunications network termination unit according to claim 7, characterized in that for monitoring, evaluation, modification and / or generation of packet data and signaling data transferred or to be transferred via the D channel, a D channel control unit (180) in 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) has access to the D-channel at a location between the first data stream conversion unit (150) and the second data stream conversion unit (160).

10. Telecommunication 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 B channels provided for user data transmission in the telecommunications network Has access.

11. Telecommunication network termination unit according to one of Claims 6 to 10, that the user data interface (140) is designed as an IOM-like PCM interface to which the telecommunication terminal devices to be connected are connected

Interposition of a CODEC filter can be connected.

12. Telecommunications network termination unit according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that it is designed such that it can be connected as or as a telecommunications terminal to various types of telecommunications network termination units.