Abstract: Method for manufacturing a thermopile on an electrically insulating substrate. A pattern is arranged on this substrate of parts which consist of a first conductive material, to which a second conductive material is applied, and parts which consist only of the first conductive material. The second material is better electrically conducting than the first and, connected as thermopile, can thereby generate a certain thermo-voltage. The second material is applied to the first, starting from a layer of the first material on the substrate, by etching stripes therein via the so-called “blind-hole etching” technique and applying the second material in these stripes.

Abstract: A system for operating a communication system comprising one or more transmitters and receivers. The transmitted signals are provided with a preamble for training the receiver and/or the transmitter being in communication. The quality of the received signal is measured and compared with a threshold. If the quality is higher or lower than said threshold, a short preamble processing or a long preamble processing, respectively, is used. More than one threshold and associated pairs of preambles having different length may be used.

Abstract: Mass flowmeter comprising a hollow conduit of a heat-conducting material for transporting in a determined flow direction a fluid with a mass flow rate to be measured, a first temperature-sensitive resistor element at a first position in thermal contact with this conduit for supplying heat to said fluid, a temperature sensor and measuring and control means connectable to the resistor element and the temperature sensor, wherein the temperature sensor is provided in thermal contact with the conduit at a second position upstream in relation to said first position, and the measuring and control means are adapted to maintain a constant difference in temperature at said first and second positions.

Abstract: Method for momentarily identifying the composition of a gas or fluid flow, and device for carrying out the method.The flow is conducted through an orifice in a conduit. Parallel to--and passing over--the orifice, there is a capillary conduit having a mass-flow meter therein. There is measured a combination of physical properties. By comparing said combination with values from a table, each of which is associated with a specific gas composition, the current composition may be determined.

Abstract: A receiver, and a method for operating the receiver, for a station in a wireless local area network using a common wireless communication channel and employing a CSMA/CA (carrier sense multiple access with collision avoidance) protocol includes various modes. In normal mode, the receiver follows typical states in order to detect a message and demodulate data from the message properly. Meanwhile, a process implements a message-in-message (MIM) mode when an energy increase above a specified level is detected. While in the MIM mode, if a carrier is detected, the energy increase is caused by a new message; otherwise, the energy increase is caused by an interfering station. If the carrier is detected, the receiver begins retraining so that it can start receiving the new message as soon as the first message ends. If no carrier is detected, the receiver waits a specified time to detect a carrier or for the end of the first message, after which the receiver returns to the beginning of the normal mode.

Abstract: A wireless LAN includes first stations adapted to operate at a 1 or a 2 Mbps data rate and second stations adapted to operate at a 1,2,5 or 8 Mbps data rate. The 1 and 2 Mbps rates use DBPSK and DQPSK modulation, respectively. The 5 and 8 Mbps rates use PPM/DQPSK modulation. All four data rates use direct sequence spread spectrum (DSSS) coding. All transmitted messages start with a preamble and header at the 1 Mbps rate. The header includes fields identifying the data rate for the data portion of the message, and a length field. For a 2 Mbps transmission the length field identifies the number of bytes in the data field. For a 5 or 8 Mbps the length field identifies the number of bytes in the data field which, if transmitted at 2 Mbps, would take the same transmission time of the data field, and is thus a fraction 2/5 or 2/8 of the actual number of the bytes. With this arrangements, all the stations are interoperable in a co-existent manner in the LAN.

Abstract: The invention relates to a store arrangement for purchasing articles in a self-service store according to a self-registration system whereby a client himself registers articles selected by him with a scanner. The store arrangement includes at least one identification device for recognizing a client and a readout station for reading out the articles registered with the scanner. The store arrangement further comprises a paying station for paying in electronic manner and without intervention of store personnel for articles read from the scanner by the readout station, and for clearing a passage for the client to leave the store when the articles have been paid for in electronic manner.

Abstract: A local area network station for receiving data symbols encoded in a spread spectrum code and transmitted over a wireless channel includes in-phase and quadrature correlators (42, 44) the output signals of which are used to address a look-up table (50) for conversion to amplitude and phase sample signals. Corresponding amplitude sample signals are integrated and stored in a plurality of registers (96) and for each symbol, the register (96) storing the maximum value is ascertained to identify the associated sample number, which is stored in a sample number register (160). This sample number is utilized to determine the time of a symbol clock signal (RXCLK) used for clocking the received data.

Abstract: A multipoint data modem communication system includes a control modem (12) and a plurality of tributary modems (14, 16, 18). During an initial training mode, receiver parameters and equalizer coefficients are determined and stored in a storage device (156) in the control modem receiver at addresses associated with the tributary modems. During subsequent relatively short training signals, the stored parameters are accessed. The remote modems transmit identification address tones in parallel with the subsequent training signals, at frequencies separated by 200 Hz intervals from the training signal spectrum frequencies. A plurality of Discrete Fourier Transform (DFT) filter circuits (190) are utilized to determine the transmitted addresses by measuring the correlation of the received signal with locally-generated frequencies.

Abstract: Digital Data receiving apparatus includes means for adjusting the timing of the sampling instants. A phase controlled oscillator (PCO 19) provides timing signals for sampling the received signal and is controlled, at the commencement of a received signal, by a timing initialization circuit (17) responsive to repetitive phase alterations in a training sequence. The timing initialization circuit (17) includes a plurality of Discrete Fourier Transform (DFT) circuits (23) responsive to frequencies dependent on the power spectral densities of the received signal, which received signal may be modulated at a normal rate or a fall-back rate. The DFT circuits (23) measure the correlation of locally-generated frequencies with the incoming samples for a predetermined number of such samples to produce a plurality of complex signals. A selector circuit (24) selects a pair of the complex signals dependent on the modulation rate.