Device for a time division multiplexed digital telecommunication exchange.

The invention relates to a digital time-division multiplex telecommunication exchange according to the preamble of claim 1.

A special feature of this proposed time-division multiplex telecommunication exchange is the kind of establishing conference connections and the integration of the actual conference unit in the central office, which allows the voice mail, preferably the voice mail of a group coupler the exchange exploit as a conference space. There are in this connection on an input side and output side of the voice mail attached super highway on the transmission of information from and to participants formed of two compounds transmission time slots also formed additional conference time cells. The voice memory and its associated latch are extended corresponding memory cells in this context to the additional conference time slots. Furthermore, the conference unit is placed in a feedback loop from the output of the speech memory to its input. Takes you through either free reading of the speech memory in such a conference time slots implemented individual signals of the conferees participating in a conference on, forms from conference subscriber-sum signals, not their own share of the conference participant, for whom they are intended, this reflects the input side in the associated Konferenzeitfächern to voice memory, are read from where this sum signals during the conference subscriber-transmission time slots and forwarded to the conference participant.

A feature of modern digital telephone exchanges is also the possibility of insertion of audio signals to one of the participants in a two-party connection.

The object of the invention is now to implement this feature in a Fernmeldevermittlungysstelle specified in the preamble of claim 1 type with the smallest possible circuit moderate effort.

This object is achieved by the features specified in the characterizing part of claim 1 means.

The inventive solution is based on the principle of the Toneinblenung involve the conference unit, including the principle of presumed specific nature of the preparation of conference calls will be extended by additional Tonsignalzeitfächer or additional memory cells in the voice mail and whose latches are provided and by the actual conference unit to the possibility of forming another individual sum is extended, in which it is the sum of the audio signal samples of clay to be inserted and the speech samples of a participant of the two-way connection, which is not affected by the Toneinblendung.

The invention by way of example with reference will be explained in greater detail to a drawing.

In the drawings:<ul><li>1 shows the exemplary structure of a digital time-division multiplex telecommunication exchange.</li><li>Figure 2 that part of such a time-division multiplex switching center in which the invention is implemented.</li><li>Figure 3 shows an embodiment for the construction of an equipped to Toneinblendung conference unit that time division multiplex telecommunication exchange.</li><li>4 a the voice mail and conference unit pointing block diagram illustrating the time slots implementation in accordance with the invention realized Toneinblendung.</li></ul>

The terminal groups LTG1 to LTGn form the interface between the analog or digital environment the exchange and the switching network. On it are accordingly with users connecting subscriber lines and / or connecting with other exchanges interconnectors PCMe0 connected to PCMe11.

The terminal groups as essential components, as shown in the terminal group LTG1 in detail, terminal units LTU 1 to LTUx, which in turn contain the subscriber sets or wiring harnesses, not shown here, also his group coupler GS, an interface unit LIU that the interface between the terminal group and the group switch represents a signal unit SU, and a group processor GP that controls the aforementioned units and furthermore processed on the subscriber or connecting lines received dialing information and in connection with the establishment and release of connections to the coordinate processor CP is in control characters exchange. In addition, the group processor performs GP routine checks and assumes monitoring tasks.

2 shows a detail here of interest of the terminal group LTG is the arrangement according to Figure 1 dargestelt more detailed extent.

It is provided that the connection of 12 PCM lines, on each of 32 time slots are formed. The branches for the incoming transmission direction PCMe0 to PCMe11 this PCM lines are connected to a serial-parallel converter SPC, which also acts as a multiplexer, through which the individual bits of the incoming to the PCM lines PCM Wote by a serial-parallel conversion on the 8 wires of the receiving branch SMLe a multicore Super highway to be distributed under the condition of 8 bits per PCM word and the plexleitung by multiplexing on this multi be interleaved in time such that initially sequentially on the PCM lines PCMe0 to PCMe11 in timeslot 0 transmitted PCM words occur successively, then successively transmitted in time slot 1, etc., and finally the data transmitted in timeslot 32 PCM words.

However, the sequence control of said multiplexer operates with such a high readout clock that besides the 12 x 32 = 384 time slots for the PCM words of the 12 PCM lines, which are referred to as transmission time slots, additional time slots are formed, referred to herein as conference time cells. According to an assumed maximum number of 4 conferees per conference and 32 simultaneously possible conferences, these are 4 x 32 additional time slots, which form 32 groups of 4 sequentially occurring time slots.

The mentioned receiving branch SMLe the super highway leads to a voice memory SM, which together with the corresponding control the group coupler GS according to FIG. 1

The voice memory SM has in accordance with the formed on the super multiplex line 384 transmission time slots to 384 memory cells for each 1 PCM word. In addition, according to the mentioned additional conference time cells, it has more memory cells 128 for each one PCM word, the form 32 are respectively a conference associated with groups of four memory cells for 4 beteiligbare a conference conference participants. Writing in the voice memory SM of the incoming branch SMLe the super highway from cyclically, the reading on the outgoing branch SMLa the super multiplex line contrast randomly. In this outgoing branch SMLa the super multiplex line corresponding conditions prevail as in the incoming branch SMLe.

Figure 2 also shows a conference unit CONU lying in a feedback loop through which is connected with a corresponding switching position of switches S1 and S2, the output of the speech memory with its input. Receipt of the conference unit is CONU means LIN for converting non-linear code representation arranged in linear code representation, the output side of the conference unit means COM which is the opposite conversion of linear code representation in nonlinear code representation.

The illustrated arrangement is under the control of a controller GSC, the central part of a holding memory CM which provides the drive addresses for the optional reading of the speech memory SM. This voice mail therefore contains an equal number of memory cells as the voice memory SM, of which are those that receive the drive addresses for contiguous with the conference memory cells in the voice memory grouped in a corresponding assignment, namely 32 four groups according to corresponding to 32 possible simultaneous conferences, each with four memory cells four conferees per conference included. Other components of the control GSC are a processor interface PS to a microprocessor uP, a counter ZZ, the drive addresses for the 512 memory cells of the speech memory SM during cyclical writing provides further an input time slot counter EZ that counts the transmission time cells to the super multiplex line for the incoming transmission direction SMLe and after whose lapse respectively the switch S2 is operated. Finally, an output timing counter AZ is provided, the transmission time slots is one in a similar manner to the super multiplex line for the outgoing transmission direction SMLa and provides a control signal for the switch S1.

3 shows an already proposed solution for the construction of the conference unit (CONU), with the proviso that a maximum of four conference participants can join a conference. It will first be considered in this context, the part shown above the dotted line of FIG. 3

The conference unit according to Figure 3 thus has four temporary registers A, B, C and D, in which the coming of the conference individual signals, which have been implemented by means of the voice mail to the corresponding conference time slots, are cached.

The conference unit according to the invention further comprises an adding network which consists of adders AK1 to AK6, which are arranged in two stages of which the first stage of the adder AK1 and AK2 and the second stage comprises the adder AK3 to AK6. The adder AK1 is connected to the outputs of the buffer register A and B, and accordingly forms from the individual signals of the subscriber A and B, the partial sum A + B of adder AK2 is connected to the intermediate register C and D, and accordingly forms the partial sum C + D from the individual signals of the conferees C and D.

The adder AK3 Addiernetzwerkes of a single signal, namely the content of the register A, and the output from the adder AK2 partial sum signal C + D is also supplied. It thus provides a Endsummensignal SB = A + C + D, which is temporarily stored in an output-side intermediate register SB. Similarly, the adder AK4 obtained from the intermediate register B. from conferee B supplied single signal and the partial sum signal C + D is formed by means of the adder AK2, from which he = B + C + D is the final sum SA, which is temporarily stored in the output-side intermediate register SA , The contents of the intermediate register C is supplied with the output by the adder AK1 partial sum signal A + B adder AK 5 to form the Endsummensignals SD = A + B + C, which is temporarily stored in the output-side intermediate register SD. Finally, the adder AK6 serves to form from the contents of the intermediate register D and the output by the adder AK1 partial sum signal A + B the Endsummensignal SC = A + B + D, which is temporarily stored in the output-side intermediate register SC. With a larger number of conferees maximum beteiligbaren the adder network comprises a further stage of adders, which then only partial sum signals are supplied as input variables.

Under the control of a controller St, which also causes the timely entry into the aforementioned input-side intermediate registers A to D, the contents of the output-side intermediate register SA is read to SD during corresponding conference time slots.

With regard to the utilization of the conference unit CONU to Toneinblendung the conference unit CONU, enhanced by the components shown in Figure 3 below the dotted line. It involves two other input-side intermediate register E and F to a further adder AT, which processes the signals in these intermediate registers to Tonsummensignal E + F, and to an output-side intermediate register SE which receives this Tonsummensignal.

With regard to the Toneinblendung more additional time slots are further formed on the super highways SMLe and SMLa which are hereinafter referred to as Tonsignalzeitfächer. According expanded are also the voice memory SM and the latch to this Tonsignalzeitfächern assigned additional memory cells.

The extensions referred to comply with extensions that would be required if instead of the assumed maximum 4 conferees per conference participants, the participation of a maximum of 6 meeting would be possible. In this case can be 32 different sounds in two compounds show.

Below is first received on the processes involved in the development of a normal two-party connection. Assume that a connection between a subscriber A and a subscriber B should exist, the associated in them time slots on the incoming branches PCME the time division lines or in the corresponding transmission time slots on the Super highway for the incoming transmission direction SMLe PCM words to the voice memory SM supply in which these assigned in these time slots in the course of the cyclical writing memory cells are stored. By selectively free reading arrive originating from the subscriber A PCM words in the on the Super highway for the outgoing transmission direction SMLa subscriber B associated transmission time slots, whereas conversely arrive originating from the subscriber B PCM words in the subscriber A assigned on this highway SMLa transmission time slots. The conference unit has no function in this context.

Description will be made on the processes involved in the development of a conference, where it is assumed that four conferees A, B, C and D are involved. This conference participants provide individual signals in the form of corresponding PCM words in them to the incoming branches PCME the time division lines or in the in on corresponding transmission time slots on the Super highway SMLe for the incoming transmission direction to the voice memory SM, in which they, as indicated above, by cyclically registered the transmission time cells assigned memory cells are stored. For random reading of the relevant memory cells now takes place but in contrast to the situation in the above-mentioned two-way connection, a reaction in formed on the super highway SMLa immediately successive conference time slots of the conference associated with the relevant group of conference time cells. About the switch S2, which is controlled by the counter AZ during these periods assumes the switching position shown, and on the establishment of LIN, which performs linearization, they get to the conference unit CONU.

There are four Endsummensignale are formed, each of which, do not contain the individual signal of that conference participant, for whom they are intended. This Endsummensignale reach a caching in the caching SA, SB, SC and SD and after a code conversion of linear coding in nonlinear coding by means COM in corresponding successive conference time slots via the switch S2, to the input of the speech memory SM, where the course the cyclical writing associated in the mentioned conference time cells memory cells are stored. then carried through optional activation of these memory cells, a reaction to the mentioned conference participants A, B, C and D assigned to the super multiplex line for the outgoing transmission direction SMLa transmission time slots formed, from where it through the now switched switch S1 to the parallel-serial converter PSC and since departing from the outgoing to the question or the relevant branches PCMa0 to PCa11 time multiplex lines.

With additional reference to Figure 4, the operations at an inventively performed Toneinblenung in a two-way connection are explained in more detail now.

If a will appear for the participant A certain tone in such a two-way connection between a subscriber A and a subscriber B, then, as Figure 4 shows, coming from the subscriber A speech samples as a normal two-way connection handle it, so by the voice memory SM GS implemented at the time of the trade to the subscriber B allotted time compartment from time specialist of subscriber A assigned time slot. The by the subscriber B upcoming speech samples and the audio signal samples are treated contrast corresponding individual signals of the conference participants in a conference connection, ie implemented by the respective transmission time slots in two consecutive additional Tonsignalzeitfächer, and the conference unit CONU supplied where they enter the input side intermediate register E and F respectively. The conference unit then forms with the help of additional adder AT a sum signal E + F, the first reaches the output-side intermediate register SE and fed back to the voice memory SM from there into the relevant Tonsignalzeitfach about the super highway SMLe, and the cyclical writing to the of such sound / voice sample mixtures provided for additional memory cells is stored. Then for random readout is a time channel conversion in the time slot of A associated with the subscriber on the Super highway SMLa timeslot to be that participant of the two-party connection supplied.