DE3300233C2 - Procedure and arrangement for code conversion for PCM transmission links with long runtimes - Google Patents

Description

The invention relates to a method for code conversion in an "outgoing" code converter in a PCM transmission system Carrying out the process is referred to the DE magazine telcom report 2 (1979), supplement "Digital transmission technology", pp. 65-71.

In the case of pulse code modulation (PCM) transmission systems, it is customary to monitor the code channels by acknowledging certain codes to be provided. For example, in the case of identification systems that transmit the identification from impulse, a release indicator is activated in the forward direction transmit a trigger acknowledgment identifier in the reverse direction. For labeling systems that use If the indicator is transmitted as a status indicator, an occupancy acknowledgment is issued in the reverse direction in response to the criterion occupancy in the forward direction. One Monitoring device checks the correct chronological sequence of this forced operation, reports a Alarm in the event of a faulty function and takes measures to initiate a lock of the channel until the fault has been rectified.

In PCM transmission systems, this task is carried out by the “outgoing” and “incoming” license plate converters at the ends of the route. In a A telephone channel of this type is ready for use when the "incoming" license plate converter from of the downstream device its readiness for occupancy as an indicator in the reverse direction reports the route to the "outgoing" license plate converter. When it is occupied, the latter gives a label in the forward direction to the "coming" label converter, which in turn occupies the downstream device via its sensor / transmitter arrangement. as Acknowledgment of a successful occupancy switches this after a time / 1 after the receipt of the number plate "Occupancy" from the indicator "Occupancy readiness", so that this change of character from the "outgoing" License plate converter can be viewed as an occupancy receipt.

If the "walking" license plate setter that

33 OO 233

"Occupancy receipt" not received, so hits a monitoring circuit from the transmission of the occupancy on after a time fc has elapsed the following measures:

Failure to confirm the occupancy is displayed optically as an alarm signal,

Forward characters are passed on from the time the "Occupancy" indicator is sent out after the expiry a time ft prevented,

the indicator »occupancy« continues to be sent out, even if the upstream device triggers the "outgoing" identifier converter and

the "outgoing" license plate converter remains blocked from being reassigned.

If the »Occupancy acknowledgment« indicator arrives at the end of the fault, the monitoring circuit must cause the following:

A message »no occupancy receipt« is deleted,

the forwarding of forward characters is enabled again,

if the trip has already taken place, the symbol "Test assignment" interrupted and as a trigger acknowledgment after receiving the number again "Readiness for occupancy", the lock against new occupancy lifted.

In order to ensure the transmission of characters, in particular the dialing information, the time values through the specification for the transfer; system PCM 30 F, part 4, system device with number plate converters, provisional edition August 1980, pages 63 and 64 given certain sizes:

fi: 0 ... 50ms
f ₂ : 60 ... 130ms
ty. 60 ... 300 ms

The object of the invention is to provide a method for code conversion in an "outgoing" code converter specify that it works reliably even with long runtimes on the transmission path, as difficulties in establishing connections such as possible corruption of election information as well constant alarm display can be prevented.

Based on a method of the type described in the introduction, this object is achieved according to the invention solved by the characterizing features of claim 1.

Advantageous refinements are set out in the subclaims marked.

In particular, the channel-specific monitoring can be ensured by the method according to claim 2.

The invention is based on an exemplary embodiment explained in more detail below.

Fig. 1 shows a PCM transmission system incorporating the invention and

F i g. Figure 2 shows an "outbound" flag converter according to the invention.

1 shows a PCM transmission system with PCM terminals A 1 and B 1, earth stations A 2 and B 2 and a satellite 5. Compared to a PCM transmission system with line equipment, the transmission medium of which is, for example, a coaxial cable or a Lichtwelien'.eiter , there is a much longer runtime of approx. 260 ms per direction. As a result, the »occupancy receipt« indicator only arrives approx. 600 ms after the »Beleeuns« indicator has been sent. At these times, with conventional PCM transmission systems, an occupancy check alarm with all the consequences is triggered briefly; In particular, the temporal blocking of the forward characters can lead to an interruption of dialing pulses and thus to a wrong dialing.

2 shows a "walking" according to the invention Flag converter. The arrangement contains, as known parts, a connection 1 for a c-wire, a Sensor / transmitter arrangement 2, a monitoring arrangement 3 and connections 7 and 8 on the transmission side. According to the invention is this »outgoing identifier converter through two AND gates 4 and 6, a counter circuit 5 as well as connections 9 and 10 on the transmission side added. The counter circuit 5 contains, for example, monostable Flip-flops for the times of the license plates generated by it.

The part according to the invention with the elements 4, 5 and 6 avoids those in the description of FIG. 1 named accidents. Regardless of the arrival of the

2ö real identifier "occupancy acknowledgment ^", the counter circuit 5 outputs an identifier "advance occupancy acknowledgment" to AND gate 4 and terminal 8, which initially does not block further selection. The indicator "advanced occupancy receipt" is limited in time by the counter circuit 5 so that the early occupancy receipt can be replaced by a real occupancy receipt arriving later. In this FnIl the further connection is established unhindered. If, on the other hand, the "Occupancy acknowledgment" indicator is not received, the functions mentioned at the beginning, such as blocking the forward characters, etc., become effective _{after a time J 4 has elapsed.} This blockade can be done internally by the "outgoing" code converter according to the invention by blocking the code path for the dialing characters - in the case of direct current pulses in the character logic, in the case of multi-frequency code characters in the speech path - and via a message line to block the transmitters of external dialing registers.

During the time U , dialing information that has already arrived can be used to set a dial level following the “coming” indicator converter, even if the indicator “occupancy acknowledgment” is not received. On the other hand, time is u in general

«5 too short to reach a subscriber and block him with the» check occupancy «indicator in the event of an occupancy acknowledgment alarm. For safety's sake, in addition to detecting the absence of the flag "assignment acknowledgment" - without changing the other process steps - in the meantime transmitted a long tripping pulse and thus an occupancy any ^r additional line portions be reversed via the following the "next" Kennzeiehenumsetzer switching element addition.

1 sheet of drawings

Claims (10)

33 OO claims: 1. Procedure for license plate conversion in an "outgoing" license plate converter in a PCM transmission system, in which an occupancy on an »incoming« line, in particular a c-core, is recognized and forwarded as an »occupancy« indicator in the forward direction, in which only an indicator »occupancy acknowledgment« arriving in the reverse direction control signals releases, in which the chronological sequence of occupancy and occupancy acknowledgment is monitored and in which, if the "Occupancy receipt" indicator is missing, a "Verification assignment" indicator is sent out, characterized in that the license plate with a "coming" license plate converter over a satellite link be replaced, that after the "Occupancy" indicator was sent out, but before the expected arrival of the "Occupancy receipt" indicator in the "outgoing" indicator converter, an indicator "Advance occupancy receipt" is inserted, that during the insertion of this indicator, the transmission of weather control signals such as election information is enabled and that when the "Occupancy acknowledgment" indicator is not recognized, a "Interim triggering" indicator in Vc -.forward direction to Activation of any line sections that are already in use and following the remote station. will be. 2. The method according to claim I _1, characterized in that the indicator "advance occupancy receipt" is inserted until the expected indicator "occupancy receipt" would have to arrive over the satellite route taking into account the transit time. 3. The method according to claim 2, characterized in that the insertion time is approximately 600 ms. 4. The method according to claim 1, characterized in that the indicator »interim Trigger «is inserted until the following line sections are safely released for the remote station. 5. The method according to claim 4, characterized in that the insertion time is approximately 600 ms 6. The method according to claim 1 for an "incoming" line with a- and 6-wire, characterized in that a blockade of control signals in In the form of multi-frequency code dialing characters in the absence of an »occupancy receipt« indicator. 7. The method according to claim 6, characterized in that the transmission-side speech path of the "outgoing" identifier converter is blocked. μ 8. The method according to claim 6, characterized in that a lock via a message line the sender of external dialing registers is made. 9. "Outgoing" license plate converter to the through-b5 Implementation of the method according to one of Claims 1 to 5, characterized in that that a first AND gate (6) is provided, the first input (7) and the output (9) in the Way for the indicator »occupancy« is inserted, that a second AND gate (4) is provided, the first input (10) and the output (8) in the path for the indicator »occupancy receipt« is inserted and that a counter circuit (S) for the formation of the indicator "Early occupancy acknowledgment" and "Intermediate release" is provided, the first input (7) with the first input and whose first output is connected to the second input of the first AND gate (6) and whose second input (10) with the first input and its second output with the second input of the second AND gate (4) are connected. 10. "walking" license plate converter according to claim 9, characterized in that a microprocessor is provided which the functions of the first (6) and second (4) AND gates and the counter circuit (5)