Bbc Brown Boveri Ag

Bbc Brown, Boveri & Company, Limited

Asea Brown Boveri Inc.

Datawatt B.v.

Walter Braun

Walter Hagmann

Joachim Habermann

Peter Schranz

Bruno Maibach

Dacfey Dzung

Urs Hanselmann

A method of exchanging data in a network having a master station (M), at least one subscriber station and a common data channel according to a hierarchical token-passing principle comprises the following steps: a) at the start of the data exchange the master station (M) has sole possession of the control token; b) in order to initiate a data exchange the master station (M) sends a telegram with a time limit (T0L) specified by it to at least one receiver (E1); c) at least one receiver (E1) accepts the control token for a period limited by the specified time limit (T0L); d) at least one and every subordinate further receiver (E1, E2, E3) either passes the control token with a telegram and a further time limit (T1L, T2L) not exceeding the specified time limit (T0L) on to a subordinate further receiver (E2, E3), or allows the specified time limit to expire without relinquishing the control token; e) after expiry of the time limit (T0L) specified by it, the master station (M) again accepts sole possession of the control token.

Method of exchanging data

A process for transferring data packets in a network having a master station, plural subscriber stations, and a common gated channel, wherein each subscriber station records the data package received by it and a transmission quality level of the data package received by the respective subscriber station; each subscriber station reports the recorded transmission quality levels to the master station; the master station determines at least one data routing for each subscriber station on the basis of the transmission quality levels reported to the master station; and a data packet directed to a certain subscriber station is transferred according to the determined data routing. The process is particularly suitable fo the transferral of data packets via the supply lines of a medium- and low-voltage network.

Process for transferring data packets

In a signal transmission method, a sequence of equally distributed statistically uncorrelated symbols having a symbol duration T.sub.S is converted, in a transmitter, into a frequency baseband signal by means of a given CPM method, the frequency baseband signal is transmitted to a signal receiver by means of a carrier oscillation and the receiver is synchronized with respect to the frequency baseband signal. The signal receiver is synchronized in such a manner that, in a number N of time windows the starting times of which are displaced by an integral multiple of the symbol duration T.sub.S referred to a given reference time t.sub.R and the length of which in each case corresponds to the symbol duration T.sub.S, the frequency baseband signal is sampled in a number K of subintervals (1A, 1B, 1C, 2A, . . . ) per time window, dispers ions (.sigma..sub.A, .sigma..sub.B, .sigma..sub.C) are calculated for sampled values from subintervals (1A, 2A, 3A, . . . ) corresponding to one another and a sampling time T.sub. A is derived from the location of the smallest one of the dispersions in time. The N time windows are divided into two groups (1A, 1B, 1C, 3A, 3B, . . . ; 2A, 2B, 2C, 4A, 4B . . . ) and the dispersions (.sigma..sub.A, .sigma..sub.B, .sigma..sub.C) are separately determined for each group.

Signal transmission method

A method for demodulating an FM signal (FM=Frequency Modulation), in which the FM signal is directly mixed down into an in-phase and a quadrature component of a complex frequency baseband and a modulation signal is determined from a phase relationship of the complex frequency baseband signal, and the phase relationship is determined from a curve length of the frequency baseband signal. The curve length is approximated by a length of a polygon curve which is spanned by successive sampled values of the complex frequency baseband signal. An estimated radius of an envelope curve of the complex frequency baseband is preferably used for normalizing the curve length. A signal receiver according to the invention comprises a direct converter (2), AC-coupled amplifiers (5a, 5b), a demodulator (6a) and a loudspeaker (8).

Method for demodulating an FM signal

A method for transmitting data via the power system line of a power supply system by carrier frequency modulation, wherein an improvement in the reliability of transmission is achieved by transmitting the same information several times in succession (time diversity) of different carrier frequencies (frequency diversity). Additional coding of the data by a 'forward error correction code' results in further improvement.

Method for transmitting data via the lines of a power supply system

A method and system for the transmission of data in an electric distribution system between a central controller coupled to a medium-voltage distribution line and at least one terminal coupled to a low-voltage wherein, the transmission of data within the medium-voltage distribution line takes place at a first carrier frequency (f.sub.1), and the data at the first carrier frequency is transposed to data at a lower second carrier frequency (f.sub.21, f.sub.22) for transmission from the medium-voltage distribution line to the low-voltage distribution line by means of a transponder. Due to this transposing of carrier frequencies, the system can be optimized with respect to the different channel properties of the two communication channels.

Method for data transmission via an electric distribution system and

A PSK data transmission method wherein in the presence of disturbances which are harmonics of a common fundamental frequency, the disturbance signals are eliminated by the fact that the symbol duration (T) of the data symbols, to be transmitted, of a baseband signal (B(t)) is selected in such a manner that the period duration of the disturbance signal (S(t)) is an integral multiple N.T of the symbol duration. By forming the difference between symbols separated by N intervals from each other at the receiver side, the disturbance signal (S(t)) is completely suppressed while the data rate can be arbitrarily determined via the choice of N.

Differential phase shift keying method for the transmission of data

In a method for clock synchronization of a signal receiver, the demodulated received signal is sampled in each of the subintervals over N time windows having in each case K subintervals (1A . . . 4C). In each case, the dispersion is calculated for the sampled values of N corresponding subintervals and the K dispersion values obtained are compared with each other. The optimum sampling time is derived from the position in time of the minimum dispersion value.

Method for clock synchronization of a signal receiver

A method for transmitting digital data wherein the data are transmitted in several transmission sections (I-IV) which in each case contain several symbols (1-6). In the transmitter, the phase of a carrier wave is modulated by n different phase angles and their frequency is suddenly changed at the beginning or at the end of each transmission section. So that the individual transmission sections (I-IV) can be synchronized in the receiver, at least one symbol from each transmission section is additionally transmitted by the transmitter in another transmission section as synchronization information. In the receiver, the phases of the carrier wave within the individual transmission sections, that is to say the block phases, are first determined independently of each other by means of an estimating method directly from sections of the carrier wave modulated with the respective data, apart from a phase uncertainty of n-times. The final block phases are finally obtained by evaluation of the synchronization information.

Growing community of inventors

Wettingen, Switzerland

Walter Braun