DE1003274B - Circuit arrangement for double-directional connecting lines in telecommunications systems, especially telephone systems - Google Patents

Description

Connection lines that can be used in both directions in telecommunication systems, in particular telephone systems can be occupied at both ends at the same time or almost at the same time. Step through this Disturbances or even wrong connections occur when the two calling parties are connected together will.

In order to avoid such an interconnection of two participants, it is known to use a specific Direction to give priority. In such an arrangement, two oppositely directed Occupancy pulses on each other, then the preferred, z. B. longer rush current of the preferred Office through, so that a connection is guaranteed in the direction from the preferred to the other office will. Establishing a connection in the opposite direction is prevented. Instead of an extended one single occupancy impulse one has already used impulse series. Has a disadvantageous effect in both If the shortening of the time available for free voting at the arriving end fails, see above that there is a risk that individual number current surges of the number current surge series sent out not yet completed occupancy can be swallowed, so that incorrect connections arise. Also can because of the different lengths of the occupancy pulses, the transmissions will no longer be uniform.

In other known arrangements one is of preferring one particular direction through different ones Allocation criteria passed and used the same criterion in both directions. here the occupancy pulses are transmitted in both directions over the line and on both sides of the line included in the incoming transmissions. The occupancy pulse causes the incoming transmissions relays operated on both sides of the line for the calling part - Activate the party on a busy signal. After the duration of the occupancy pulse has expired Time the blocking of the connection device intended for incoming traffic is lifted. If one of the two calling subscribers hangs up his receiver, the occupancy relay comes from him busy outgoing transmission to the garbage, and the connection it established is released. As soon the subscriber who first hung up and seizes the connection line again addresses the seizure relay in the outgoing transmission. It a new occupancy pulse is given over the line and thereby the incoming one on the other side Transmission busy, regardless of whether the line in the outgoing direction is still blocked there, because the other participant may not yet has hung up. The one participant who comes first

Circuit arrangement for double
directional connecting lines

in telecommunications systems,
in particular telephone systems

Applicant:

Standard Elektrik Aktiengesellschaft,

Stuttgart-Zuff enhausen,

Hellmuth-Hirth-Str. 42

Willy Bergholtz, Stuttgart-Zuffenhausen,

and Nikolaus Lewen, Stuttgart,

have been named as inventors

If you hang up the handset and then seize the line again, the connection line receives. This arrangement however, there is a lack of them in the case of long vex connecting lines is only useful if four-wire lines are available, because two-wire lines interfere with each other Impulses.

Arrangements are also known in which, when switching indicators such as occupancy pulses are transmitted, or dialing current surges switched off the receiving device at the sending end of the line is. On after the transfer of the switching indicator has ended Switching indicator arriving on the line from the other end influences control means which control the transmissions at both ends of the Connection line under the influence of closing agents at the other end of the connection line place. If the connection line is occupied at both ends at the same time, it will probably open the outgoing transmission is busy on both sides. However, there is no incoming assignment on either side instead of. If a subscriber now sends out dialing current surges, these are transmitted via the connection line transfer. On the other hand, the aforementioned control means come into effect and now indicate the simultaneous assignment on both sides. For both connected to the line Subscriber is switched on a busy signal.

The triggering of the connection and a reassignment of the line is now solely from that of the dialing current surges depending on the sending participant. Switching measures of the subscriber at the other end of the line, z. B. Delivery of electoral surges or hanging up

609 837/142

of the handset, affect the switching state of the connection devices not. The connection line can be triggered and reassigned from this So not done on the side.

In addition to the disadvantages already mentioned, all known arrangements have the deficiency that either both calls or one of the two is lost, d. H. lead to loss assignments. The disadvantages of these known arrangements are according to the invention thereby avoided that the transmissions assigned at both ends of the connecting lines Switching means with simultaneous or almost simultaneous occupancy from opposite directions cooperate in such a way that the occupied connection line without interconnection of the two Participants from both sides released and the assignment for each of the two calling stations another free connection line is initiated. The simultaneous occupancy of the connection line Switching means coming into effect from opposite directions switch the Annealing chains continue at both ends of the connecting line and form a circuit for extension of the starting pulse. Another double assignment can be avoided by the fact that the Further switching of the starting chains is made at different time intervals or that the connecting lines are crossed.

The invention is now based on the in the drawing Described embodiment shown in more detail. All the switching details not relating to the invention are shown in simplified form or are omitted.

Fig. 1 shows the at both ends of the connecting line connected transmission;

Fig. 1 a and 1 b show the two options for preventing repeated double occupancy.

Outgoing assignment of the connection line

40

It is assumed that the transmission shown in FIG. 1 is in an end office and the connecting line VL leads to a similar transmission in the nodal office. The first free voter PW is started in the end office in a known manner via an event chain. At the same time is over

+, anl, eil, fwl, el, gl, AH, -

the transmission relay AH switched on. When the selector FW is switched through by pulling the bridge: The response circuit for the relay AH is disconnected again. During the drop-out time of the Sendexelais AH , the receiving relay / is activated in the upstream node office and blocks the line for occupations from this office. When the transmission relay AH responded, relay G was energized via contact α / ζ · III. With contact g II relay C 2 is energized, which applies test potential to the c-wire with contacts21 and maintains its own contact in a manner not shown. The connection line is now checked and blocked in a known manner. The switch or voter can pick up voting impulses.

Incoming assignment of the connection _{cable 6}

The assignment of the transmission, arriving from the node exchange, is achieved when an assignment impulse arrives by responding to the relay /. Contact! I switches on the relay E , which continues to hold the relay chain with contact eil, so that the outgoing transmission, ie the connection line, cannot be occupied.

Simultaneous assignment of the connection line from opposite directions

As already described, when the connection line is occupied in the end office, the transmission relay AH is energized in the transmission and a warning pulse is thus transmitted to the following node office. Before this occupancy pulse takes effect there and blocks the occupied connection line in the incoming direction, an occupancy can already take place with the transmission of an occupancy pulse over the occupied connection line for transmission in the end office. There is thus a double assignment at both ends of the connection line in the transmissions.

When the transmitter relay responded, relay G was energized via contact ah III. Relay G separates with the rest side of its changeover contact g I the response circuit of the relay AH which carries out the occupancy and which sends an occupancy current surge via the connecting line. Since relay / has responded at the same time due to the occupancy in the incoming direction, relay C 2, which applies the test potential to the c wire with its normally open contact c2I, cannot be excited because contact! I switched over and relay E had responded. This prevents relays P and A from responding and line ¹ from being switched through. In the case of a double occupancy, the relays G, J, E are therefore energized in the transmission, so that over

+, α »II, AN, c2II, gl, el, G (II), -

a holding circuit for relay G is established. The winding of the common starting relay AN is in the same circuit. Relay ON extends the start impulse, whereby the next bridge of the selector is started via the switched contact and the next free connection line is occupied. The previously occupied connection line is released. This process takes place in both transmissions both in the node exchange and in the end exchange. In order to avoid a renewed double assignment, as shown in Fig. 1 a, the further switching of the starting chain in one of the two offices can be delayed. A delay in the forwarding can be avoided if, as shown in FIG. 1b, the lines are crossed, so that repeated double occupancy is avoided with simultaneous forwarding in the end office and in the node exchange. Both connections can now be set up on separate paths.

Claims (5)

PATENT CLAIMS: 1. Circuit arrangement for double-directional connecting lines in telecommunications, in particular telephone systems, characterized in that the transmissions at both ends of the connecting lines associated switching means (AH, G, I, E) cooperate with simultaneous or almost simultaneous occupancy from opposite directions in such a way that the The busy connection line is released from both sides and the assignment of another free connection-line is initiated for each of the two calling points. 2. Circuit arrangement according to claim 1, characterized in that the simultaneous Assignment of the connection line from opposite Switch means (G, E) which come into effect in the set directions switch the starting circuits (e.g. starting chain) on both sides and form a circuit to lengthen the starting pulse. 3. Circuit arrangement according to claim 1 and 2, characterized in that the relaying the starting circuits are made at different time intervals at both ends. 4. Circuit arrangement according to claim 1 and 2, characterized in that the connection Lines are connected at both ends in a different order (Fig. 1 b), so that when switching on the output circuits, a different connection line is occupied on each side will. 5. Circuit arrangement according to claim 1, characterized in that the release of the connecting line occupied both sides without prior interconnection of the two Participants who had seized this connection line at the same time. 1 sheet of drawings ■ 609 837/142 2.57