SU794653A1 - Method of transmitting time signals through synchronous discrete communication channels - Google Patents

Description

I

The invention relates to the synchronization of time scales, in particular, to methods for transmitting time signals over synchronous discrete communication channels.

Methods are known for synchronizing time scales using a transported standard, transmitting time signals over radio and satellite communication channels 1.. The method of transmitting time signals via radio and satellite communication channels is inherent in a number of significant drawbacks: susceptibility to strong interference from radio interference, high cost of newly created time signaling networks due to the need to re-organize the network of communication channels, etc.

The closest in technical essence to the invention is a method of transmitting time signals over synchronous discrete communication channels, according to which the timing of outputting time signals by a master station, taking into account the magnitude of the propagation time of signals between the master and slave stations, is shifted towards the front end. the time scale of the slave station and transmit them back to the master station 2.

A disadvantage of the known method is that increasing the accuracy of time signal transmission leads to an increase in equipment availability time due to the need to rephase it after the master station shifts time signals intended for transmission by the amount of signal propagation time between the master and slave stations. The purpose of the invention is to improve the accuracy of synchronization by reducing the time

0 phased instrumentation.

To do this, the way of transmitting time signals via synchronous discrete communication channels at the leading station is encoded by the position of the time signal to be transmitted within the parcel, the code is transmitted to the slave station, and then transmitted to the slave station, taking into account the delay at the time of code generation, or delay transmit to the master station

Q where after receiving the code, the position of the time signal inside the next burst is restored, then the interval of the menade is restored by the time signals transmitted to the channel and shifted by half the measured value, and at the slave station the position of the time signal is restored after receiving the offset signal code inside the next burst and use this signal for synchronization.

In addition, in order to increase the accuracy in transmitting binary information at the slave station, the time interval between the decoding moment of the signal received from the master station and the next transmission clock is additionally determined, the interval is encoded, its code is transmitted to the master station, where it is decoded and taken into account when measuring.

FIG. 1 and 2 are timing diagrams explaining the principle of transmitting time signals over a synchronous discrete communication channel; in fig. 3, 4, and 5 are timing diagrams explaining the principle of transmitting time signals over one of the synchronous channels of a multichannel binary data transmission system.

FIG. Figure 1 shows the time diagrams explaining the principle of time signal transmission if the slave station retransmits the time signals to the side of the master station with a delay of the time it takes to form the time signal code. FIG. Figure 2 shows the time diagrams explaining the principle of time signal transmission, if the slave station retransmits the time signals to the side of the master station via the loop formed at the slave station, i.e. without delay.

The signal from the reference time signal sensor (EDSB) (see Fig. 1) enters the input of the master station with a delay relative to the boundary of the synchronous parcel TO duration by the value of TA- When the master station receives a signal from the EDSV, the master station begins to generate and simultaneously transmit in channel time signal code, which includes directly the transmitted time signal code — the prefix code and the time signal position code inside the synchronous parcel — the interval code (toe)

The slave station receives a time signal code from the channel and with a delay of magnitude TO retransmits the code to the master station. In addition, the slave station after receiving the prefix code and the slot code (tto - TA) restores the position of the received time signal within the next burst, i.e. after receiving the time signal code, the slave station generates a signal with a delay of TAV after receiving the signal code time in a similar way, restoring the position of the time signal inside the next burst, forms a signal with a delay of TA value.

According to FIG. one

TSM (0 - + + + “l

-fp + + (1)

Tysm (- "A + 4- tc + + c +" l -

32tp + 2te + V (2)

where Gsm is the time interval Between the moment of postduction. the output of the master station of the signal from the EDSB and the moment when the slave recovers the position of the received time signal from the packet;

Tizgl is the time interval between the moment when the signal from the VLF signal arrives at the input of the master station and the time when the master station restores the position of the received time signal inside the parcel;

Tp - value, equal to the delay in the propagation of the signal between the master and slave stations in the communication channel.

In view of (2), expression (1) takes

Reed

(3)

si - o

i.e. during synchronization of the time slave of the slave station, the master station must shift the signals intended for the 5th point of transmission by time, one EDS, in the direction of advance by

(T h-ch.).

From FIG. 2 shows that

7cm (in - “A) + -Cp + tc + 30: -Cp- | .t, T,; (4)

T s (in -) + p + p + c + - “A

2Tp + Te + V (5)

35 with account (5) vtsrazh. (4) takes

view

 (G, zi-bc-bc), (6)

BUT-

i.e. in case of retransmission by the slave station of the sngyal without aderki by the value of Tc, the leading station must move the intended for transmitting signals of the time of the VDSB to the direction of advance by the amount of

y (2 ss + t.).

FIG. 3 shows time diagrams for the case when the slave station, after the reception of the time signal code performs decoding of the received signal, encodes an interval (that is-tv) between the TA decoding cycle and the next transmission clock, and with the same transmission clock starts transmitting the time signal code side of the lead station.

FIG. 4 shows timing diagrams for the case when the station is known

receives and simultaneously transmits the prefix code and the slot code (TA) to the master station, and after receiving them, decodes the received time signal, encodes the interval

(to - tv) between decoding

The TA And the next transmission cycle and with the stHM transmission cycle begins to transmit this code towards the master station.

In order to unify the transmitting and receiving devices of the master and slave stations, it is advisable that the code of the transmitted time signal includes the prefix code, the interval code (TO - TA) between the EDSB signal to be transmitted and the border of the transmitted parcel and the interval code (TGT) between the moment when the slave decodes the received TA signal and the next transmission cycle. BECAUSE the master station does not need to transmit an interval code (tp-Gv, the leading station can transmit some overhead code instead of an interval code (tp-tp).

FIG. Figure 5 shows diagrams for the case when a known station, having carried out a lekodioing of the received signal at the moment of its recovery INSIDE the next Hoggle, by sending the code of the parcel time signal TA, begins to encode the time interval (m) between the moment of copying T and the next tact of typing With the same tact, the train starts to form and simultaneously switch the PreLicke code and the interval code (TGP-TV) towards the master station.

In this case, the time signal includes the copy of the prefix and the code of the interval between the time signal. designated for transmission, and edges. the transmitted parcel is the code (TO-TA), for the master station and the code (TO-TV) for the driving station.

From FIG. 3 it can be seen that when a signal from EDSB arrives at the station entrant's entrance, the station starts forming and simultaneously transmitting the prefix code and the interval code frn-T into the channel, and instead of the interval interval (or TP) forms the service information code and sends it to the channel.

No The station receives from the channel a prefix code, an interval code (to-t) and a service inoormap code, and upon the completion of their reception, coding the received time signal code, encodes the interval (T-TV) between the time of leidopost 7d to the next. With a tact of a peregsach, and with the same transmission clock, it starts transmitting the code of the prefix, the interval kot (tp - t) 1t .. to d. In addition, the knowledge of Gtany. decoding the received interatal code (. restores the position of the received signal INSIDE the next one after receiving the prefix code, interval code (TO-TA), and overhead code) of the parcel and uses this signal to synchronize its time scales.

In the same way, the master station, by decoding the received interval code (TO-TA) and the interval code (TO-THB), restores the position of the received time signal inside the next (after receiving the prefix code, interatal code (TO-TA) and the interval code ( TO - tv) parcel.

According to FIG. 3

7 cm (- l) + -Ср -f Te-L

 Tp- | -Te-fr; (7)

THSM -) + -Ср + с -f -) -f

15 + Tr + T, - -Tl + Tv. 2 (Tr + Te-LTL (8)

In view of (8), expression (7) takes

view

20

(9)

T --- T

cm - n ism

i.e., to compensate for the delay in delivery of the reference signal, the master station must shift the transmitting time signal EDSB in the direction of the advance by the amount Tmiz. 4 shows that

7cm (% -) + tp 4- - "with 4-

 Tr + .4 -%; (10)

Tnem 0 - -EL) + i: p -f (-Co-ta) 4- +

 + + tL-Te, (P)

t e. if the slave station retransmits the prefix code and the interval code (TO-TA) without delay by the value of Tc, the master station must shift the ptee assigned to transmit the signal to the forward direction by the value of- (Uizm-f) According to FIG. five

7cm (TO -) + Tr -f H-l Wed 4-H 4-

(12)

7ism - (v - l) -f-Cp + -f + (TO - TV) 4+ T, + Tr + (Cp4-Tc + TD (13)

In view of (13), expression (12) takes the form

g Lr

(14)

55

cm - n ism

Expression (14) determines the amount of time required by the master station of time-shifted EDSB signals when synchronizing slabs of the slave station in the case where the slave station decoded the received signal at the moment of recovery inside the next one (after receiving the prefix code and interval code (TO-TA) parcels TA, begins to encode

the time interval (TO-Tv) between the moment of TA decoding and the next transmission clock and with the same transmission clock starts forming and simultaneously transmitting to the master station the prefix code and the interval code (that is, TV).

Thus, the present method eliminates the need for re-phasing of the equipment after the time station displaces the time signals to be transmitted by the master station, which results in a reduction in the equipment uptime.

In the presence of multichannel systems for transmitting binary information, the method will allow transmitting time signals along any of the synchronous channels of the system with sufficient accuracy, eliminating the need to organize special synchronous discrete channels.

Claims (2)

1. A method of transmitting time signals over synchronous discrete communication channels, according to which the timing of the time signal output by the master station, taking into account the magnitude of the signal propagation time between the master and slave stations, is shifted towards oneej, use shifted signals for synchronization of the slave station time scales and transmission them back to the master station, characterized in that, in order to increase the synchronization accuracy by decreasing the phasing time of the equipment, the position of the signal at the master station is encoded In order to transmit, inside the parcel, this code is transmitted to the slave station, where it is relayed, taking into account the delay for the time of code generation, or without delay, is transmitted to the master station, where after receiving the code, the position of the time signal inside the next parcel is restored, then the interval between the restored and transmitted to the channel time signals is measured, and half of the measured value is shifted, and at the slave station, after receiving the offset signal code, Assumption of time within the next signal and sending this signal is used for synchronization. 2. The method according to claim 1, wherein By the fact that, in order to increase the accuracy of the transmission of binary information, the slave station additionally determines the time interval between the moment of decal of the signal received from the master the station, and the next transmission cycle, encode this interval and transmit its code to the master station, where it is decoded and taken into account when publishing. Sources of information taken into account in the examination 1Time and frequency. Ed. J. Jesperson. - M., Mir, 1973, p. 39-70. 2 USSR Certificate of Entitlement No. 2483156 / 18-10, cl. G 04С 11/02, 10.05.77 (prototype). Signals / s evil tn-tA npeais Cfif, I I I I I I I I I I I I I I I I I I I I I I I I I I I I Stations A P ”(Beoustsk) Sgantantsi PM () Station V PM (Bedom) Station 8 Pt (Bedoma) L I I I I I I I I I Shz Tegsh Signals / 1s USV ifff .. | | | | | | I I Station A Pd, (Bedouta) Station A Pm (Bedoucher) Station B Pm Shoia) Station B Pt (Bedom). III I I I X L L. HA 8 Stna / 1s EDSV. J 1 J Stations fdlS (running) 1 Station A PM (6 drives) Stages In PM (Mom) tgStations In P8 (knowledge) L-LX