Abstract: Formalization of a well-defined synchronization mechanism can be used to prove that concurrently running processes of a system communicate correctly. This is demonstrated for a system consisting of many sending processes which deposit messages in a buffer and many receiving processes which remove messages from that buffer. The formal description of the synchronization mechanism makes it very easy to prove that the buffer will neither overflow nor underflow, that senders and receivers will never operate on the same message frame in the buffer nor will they run into a deadlock.

Abstract: The present invention relates to a processing repeater for use in a TDMA communication system which is capable of providing the individual data terminals with synchronization error measurements and other control data. In the particular embodiment disclosed, the processing repeater is also capable of receiving a narrowband coarse synchronization signal from an inactive data terminal in response to an interrogation command, thereby permitting rapid initial synchronization to be achieved. The disclosed processing repeater is also capable of controlling the demand assignment process for the allocation; of time slots in response to either narrowband or wideband call requests from inactive or active data terminals respectively.

Abstract: Synchronization is a descriptive rather than an operative term It relates to the extent to which a population, or populations, of nervous elements are simultaneously active or silent without prejudice to any particular mechanism

Abstract: The purpose of this paper is to establish the applicability of program-proving techniques to the verification of operating systems, control programs and synchronization programs. All the illustrative examples to be presented use Dijkstra's P and V operations for controlling the synchronization of competing processes. However, the techniques discussed are applicable to any set of such control primitives. A major portion of the paper is devoted to the proof of correctness of two programs devised by Courtois et al. that control the sequencing of "readers" and "writers" requesting the use of a common device.

Abstract: Future systems that combine computers, digital terminals, and communications equipment present design optimization problems that require reconsideration of the traditional functional responsibilities of the respective subsystems. Several “standard” interfaces, by means of which computers and digital terminals connect to the communications systems will be required. When specifying these interfaces, consideration must be given to problems of coordination, synchronization, error control, signaling, stream multiplexing, and switch control, in addition to minimizing the technological interdependence of specific subsystem designs. A focus on some of the problems is obtained in a discussion of a detailed specification for a paticular computer-communications system interface.

Abstract: A synchronization system having a plurality of control loops operative together to optimize the rate of frequency acquisition and synchronization A first loop acquires the frequency of the unknown signal A coarse phase-lock loop then adjusts the system to provide a phase-error signal A fine phase-lock loop then makes the final adjustments to the system As each step in the synchronization sequence is achieved, the circuitry which is no longer needed is switched out of operation

Abstract: In track leveling and/or lining with a continuously advancing track tamper, the tamping tools are continuously moved relative to the continuously advancing machine frame in synchronization with the machine advance in such a manner that the tamping tools are held in respective cribs while they tamp the ballast.

Abstract: A synchronization technique for multiple channel magnetic recording systems, is disclosed. The synchronization technique involves the phase modulation of data to be recorded on each of several parallel recording channels in accordance with a repeated pseudo-random sequence. Upon recovery of recorded signals in the respective channels, the phase modulation is detected to reconstruct the pseudo-random sequence which is then autocorrelated to produce a synchronization pulse once each cycle of the pseudo-random sequence. The synchronization pulses may be employed to overcome the effects of tape skew, jitter, or the like.

Abstract: A novel technique of direct synchronization called pseudoindirect synchronization has been proposed. The performance of the system utilizing pseudoindirect synchronization has been studied and compared with that of the directly synchronized oscillator. Experimental results are also presented.

Abstract: Esso Production Research Company has found that video tape is an effective means of conducting technical training and transferring technology. Use of video tape reduces the cost of conducting technical schools. Engineers and scientists using video tape information seem to retain it about as well as they do when they get it by other means (live schools, technical reports). Limited results indicate that video-taped technical reports convey information about as well as do written technical reports. Some users prefer audio-tape cassettes and recorders for automatic audio synchronization with 35 mm slides. The general conclusion is that video tape is one more communications medium, but a good one, at the disposal of people concerned with technical training or technology transfer.

Abstract: The present gain change means represent an improvement over the time synchronization means for remotely positioned timing devices. The present improvement includes means for changing the gain so as to provide multiple correction factors in time synchronization means, and the present means have particular application where an error correction gain of less than unity is of advantage particularly in controlling group synchronization. This is also true in situations where it is desired to improve the convergence of synchronization toward a common time base. The present means also have application to group resynchronization of members that have previously arrived at a common time base or index by restricting the relative timing error between cooperating members as they change from one time base to a new time base. The present means also include means to limit the maximum amount of correction applied during any one exchange of resync data.

Abstract: In a majority of timing applications, a problem exists in setting two or more clocks to agree with one another. Present techniques using WWV or other HF broadcasts allow clocks to be synchronized within 1 msec. This paper describes a method which offers an improvement in synchronization of three orders of magnitude. Microsecond synchronization is obtained by use of the Loran-C navigation system as the link between a master clock at Boulder, Colorado and any slaved clock anywhere in the Loran-C service area. The timing system also includes a unique method for distribution of several time code formats on a single UHF channel.

Abstract: The use of artificial satellites for time synchronization of geographically distant clocks has been demonstrated as early as 1962. Most techniques up to now have been plagued with one or more problems due to satellite motion, nonreciprocity of propagation, or equipment delay measurements. By using the ATS-3 satellite with its two C-band transponder channels one can avoid these problems through simple and straightforward techniques for synchronization to accuracies of tenths of microseconds. Portable cesium clocks were used to verify the accuracy of such a system.

Abstract: A control system is provided for coded data transmission affiliated with a device for entering data into the central processor, wherein the device includes a data generator, an authorization circuit and a buffer store. According to the invention the said system includes a first circuit for controlling authorization, a second circuit for communicating with the central processor, a third circuit for error detection and for acceptance by the central processor of the entered data and means for synchronization.

Abstract: In this paper we provide a formulation of the synchronized execution of a system of tasks using generalized P and V operations. We explore the properties of such processes and present as a main result a decision procedure for settling the consistency question.

Abstract: A prototype of a semireal-time system for synchronizing the DSN station clocks by radio interferometry was successfully demonstrated. The system utilized an approximate maximum likelihood estimation procedure for processing the data, thereby achieving essentially optimum time synchronization estimates for a given amount of data, or equivalently, minimizing the amount of data required for reliable estimation. Synchronization accuracies as good as 100 nsec rms were achieved between DSS 11 and DSS 12, both at Goldstone, California. The accuracy can be improved by increasing the system bandwidth until the fundamental limitations due to position uncertainties of baseline and source and atmospheric effects are reached. These limitations are under ten nsec for transcontinental baselines.

Abstract: A digital communication system for parallel operation of 16 or more transceiver units with the use of only four interconnecting wires A remote synchronization circuit produces unit address control words sequentially in data frames of 16 words Means are provided in each transceiver unit to decode calling signals and to transmit calling and data signals The transceivers communicate with each other over one data line The synchronization unit communicates the address control information to the transceiver units over an address line and further provides the timing information over a clock line A reference voltage level or ground line completes the interconnecting four wire hookup