Abstract: The invention relates to the transmission of files in a digital broadcasting system, particularly in a DAB system according to the standard ETS 300 401. According to the invention, a file descriptor (16) is created for each file. This file descriptor is of the data group type denoted by 0011 in said standard and includes parameters (27) describing the file associated with the descriptor. The file descriptor is transmitted in the broadcasting system before the file and possibly also during the transmission of the file. The information to be transmitted is divided into segments, which are identified in a file-specifically unique manner, such as consecutive numbering, which starts from zero at the beginning of each file.

Abstract: The invention relates to a system for monitoring mobile telecommunications in a multi-operator environment. The system of the invention comprises at least one user control station (UCS) comprising a home location register (HLR) containing a unique subscription number (USN) and other required subscriber data, and an account control unit (ACU) containing the subscriber's credit information. The home location register (HLR) and the account control unit (ACU) are interconnected in order for the home location register (HLR) to be able to check the credit information of the calling subscribers in response to requests from the network operators and correspondingly to debit the subscribers' accounts on behalf of the operators by the charge of the calls made. The invention is characterized in that the visitor location register (VLR) or the user control station (UCS) can allocate several temporary numbers (TN) to each terminal.

Abstract: To prevent unauthorized reception, storage, copying and reproduction of digital media objects it is defined in addition to a scrambled broadcast format a scrambled storage format which is different from the broadcast format. A user's terminal equipment cannot receive, store or reproduce protected objects without a key which is advantageously a bit sequence stored on a portable memory medium and which can be different according to the type of use it gives entitlement to. To prevent the storing and later reproduction as such of data in the broadcast format, a time stamp is included in the broadcast format representing the time of broadcasting. A playback device cannot reproduce a broadcast-format object if the reproduction time differs from the time stamp included in the broadcast format. The reproduction time is advantageously read from a real time clock of a portable memory medium.

Abstract: The invention relates to the transmission of multimedia objects in a digital broadcasting system and particularly to the transmission of a reference system and the start-up procedure of a multimedia presentation according to the MHEG standard via a broadcasting system according to the DAB standard. According to the invention, the DAB ensemble according to the DAB standard and the service channel and fast information channel comprised by the DAB ensemble are handled as virtual, multiplexed MHEG objects, whereby they and the real MHEG objects positioned below them are referred to in a manner specified in the standard ISO/IEC 13522. In addition, information about start-up procedures relating to a multimedia program or a corresponding series of operations is transmitted in a special file, and a parameter in the file descriptor associated with said file indicates that said file contains instructions for said procedures.

Abstract: The invention relates to an adaptive detection method and detector for detecting signal states of a received quantized signal using a set of reference vectors stored in a memory (11). According to the invention, the detector comprises sampling means (4) for sampling the received signal in a sliding time window; means (2) using a self-organizing map for calculating a first corrected set of reference vectors on the basis of the stored set of reference vectors used in the detection and samples of actual signal states received in the time window; means (3) employing the K-means method or the like for calculating a second corrected set of reference vectors on the basis of the first corrected set of reference vectors and the samples of the actual signal states; and means (9) for updating the set of reference vectors stored in the memory means (11) by the second corrected set of reference vectors.

Abstract: The invention relates to an adaptive receiving method and a receiver comprising an adaptive equalizing device for processing a received signal. The receiver further comprises an adaptive detector utilizing the self-organizing map principle and operationally connected after the adaptive equalizer. The adaptive equalizer is controlled on the basis of an error between a processed signal and a detected signal.

Abstract: A portable computer telephone device comprising a portable personal computer and a mobile phone integrated into one and the same body structure said body having a display screen (3) and a keyboard member (2) for operating the computer and the mobile telephone. To improve the convenience of use of such an integrated device, the keyboard member (2) is arranged to be movable between open and closed positions with respect to the rest of the body structure (1) in such a way that in the open position the whole display screen (3) and at least the whole keyboard (4, 5) of the computer are accessible for operating the computer and in the closed position the keyboard member (2) covers a part of the display screen and leaves the buttons (6) of the mobile telephone part 3(a) of the display screen accessible for operating the mobile telephone.

Abstract: The invention relates to a method of producing waveguides by an ion exchange technique on a glass substrate. In order to be able to alleviate the tolerances allowed for the ion exchange technique, the waveguides are formed in the invention by diffusing ions which increase the refractive index away from a waveguide formed previously on the glass substrate and being wider than the optical waveguides to be produced, by using the ion exchange technique and a positive-type ion exchange mask.

Abstract: The invention relates to an adaptor device for coupling together optical waveguides of different types and a process for the production of such an adaptor device. The adaptor device of the invention comprises an optical waveguide produced on a glass substrate by ion-exchange technique, in the fundamental mode of which waveguide the field distribution of light changes adiabatically in the longitudinal direction of the optical waveguide from the field distribution of the fundamental mode of the optical waveguide produced by K-Na ion exchange to the field distribution of the fundamental mode of the optical waveguide produced by Ag-Na ion exchange.

Abstract: The invention relates to a method of cascading two or more sigma-delta modulators by applying an error signal representing the quantization error of a preceding modulator to a subsequent modulator in the cascade to be quantized therein, the quantized error signal being thereafter differentiated and subtracted from the quantized output signal of the preceding modulator. To improve the performance of the cascade, in the method according to the invention, the error signal is scaled before said subsequent modulator by a first factor smaller than 1, and the quantized error signal is scaled by a second factor substantially equal to the inverse of the first factor, before being subtracted from the quantized output signal of said preceding modulator.

Abstract: The invention relates to a method of producing optical waveguides by ion exchange technique in a glass substrate (1), the ion exchange between a source of ions (such as AgNO.sub.3) and the glass substrate (1) taking place within glass substrate surface areas (6) which do not comprise any ion exchange mask. In the method of the invention, the ion exchange mask is formed by depletion areas (5A, 5B) formed in the surface of the glass substrate.

Abstract: An alternate reverse or so-called SZ-twisting method and apparatus and cable product produced by alternate reverse twisting method and/or apparatus. Elements (2 ) which are to be alternately reversely twisted may be wires, leads, optical fibers, their groups and which can also include quads of wires, leads, optical fibers. Elements (2) to be twisted and a possible core element (9) are drawn from a fixed divider (3), preferably a perforated holeplate, through a twister (6), preferably a perforated holeplate, rotating periodically in opposite directions, to a presser (7), preferably a nipple, in which the elements to be twisted and the possible core element are pressed together, to form an alternately reversely twisted product (8). Between the divider (3) and the twister (6) pipe group (4, 5) is provided for defining the feedpaths of the elements (2) to be twisted and the possible core element (9).

Abstract: A method of and an apparatus for cooling an optical fibre drawn from a heated glass blank by passing the fibre (3) through a cooling pipe (9) in which a cooling gas (A) flows in the axial direction of the fibre around it. In order to reduce the consumption of cooling gas, the cooling gas is caused to flow turbulently (B) around the fibre by a throttle point (20) formed by a partition wall (19) in the cooling pipe, so that a laminar flow of cooling gas around the fibre is prevented and the transfer of heat between the cooling gas and the fibre is improved.

Abstract: The invention relates to a method for the manufacture of optical couplers, comprising the steps of (a) removing the jacket material over a short distance from two or more optical fibres, (b) bringing the jacketless portions of the optical fibers in contact with each other, (c) fusing the optical fibers together within the contact area and drawing them into tapers. In order that the process would be simpler and easier to control, the method according to the invention is characterized in that the optical fibers are fused by heating them by means of an arc substantially parallel to the optical fibers. The arc is excited in a chamber confined in the direction of the radius of the fibers, and it is excited and extinguished at a low frequency so that the arc strikes at arbitrarily varying points around the fibers.

Abstract: The invention relates to a method for separating a substance from an aqueous solution and/or for concentrating it by using an organic extractant. In the method the substance to be separated is caused to pass from the aqueous solution to the extractant, whereafter this extractant is evaporated in direct contact with the aqueous phase into which it is desired to cause the substance to be extracted to pass.

Abstract: The invention relates to a method of growing a GaAs film on the surface of a Si or GaAs substrate by exposing the growing surface of the substrate in a vacuum to at least one vapor beam containing the Ga elementary component of the GaAs compound, and to at least one vapor beam containing the As elementary component of the GaAs compound. The method is characterized by the steps of (A) growing a GaAs buffer layer by alternately applying the elements of the GaAs compound to the surface of a substrate heated to a first temperature one atom layer at a time, whereby in the formation of each atom layer the growing surface is exposed to a vapour beam containing one elementary component of the GaAs compound only; and (B) heating the substrate to a second temperature higher than the first temperature, and growing another GaAs layer on the buffer layer by applying both of the elementary components of the GaAs compound simultaneously.

Abstract: A method for adjusting the balancing impedance of a hybrid junction for maximization of the hybrid attenuation within the range between two operating frequencies, an upper and a lower one, when using a balancing impedance formed by two series-connected resistors (R.sub.1, R.sub.2) and a capacitor (C.sub.1) connected in parallel with one of said resistors. For the achievement of an optimal matching of the balancing impedance with the impedance of the line wo which the hybrid junction is connected to when all components of the balancing impedance are adjusted, the method according to the invention is effected in such a manner that (a) the first resistor (R.sub.1) is adjusted for the maximization of the hybrid attenuation at the upper frequency, (b) the capacitor (C.sub.1) is adjusted for the maximization of the hybrid attenuation at the upper frequency, (c) the second resistor (R.sub.2) is adjusted for the maximization of the hybrid attenuation at the lower frequency, (d) the first resistor (R.sub.

Abstract: The invention relates to a method and arrangements for increasing the dynamic range at an input stage of an optical receiver, which input stage comprises a photodiode acting as a photodetector and an amplifying means the input of which is connected to one terminal of the photodiode. The input of the amplifier is connected to a diode attenuator the dynamic resistance of which is adjusted by means of a direct current proportional to the received optical level and substantially greater than the peak value of the detected signal current. At low levels of the optical signal the diode attenuator is brought into a high-impedance state.

Abstract: A stand for adjusting the viewing angle of a display terminal, including a sleeve-like frame portion (1) an inner boring of which is at one end thereof enlarged into a socket provided with a slide surface (3) for a slide part (4) to be attached to the display terminal and provided with a slide surface (5) complementary to the slide surface (3), the slide surfaces having a center of curvature (11). A supporting member (6) is positioned in the inner boring (2) of the frame portion (1) and is rotatably journalled at one end (10) to the slide part (4) acentrically with respect to the center of curvature of the slide surfaces and between the center and the opposite end of the member. A resilient element (8) is fitted between the frame portion (1) and the end of the supporting member (6) remote from slide part (4) to create a holding force between slide part (4) and the socket of the frame portion (1).

Abstract: The invention relates to a method of and a device for simultaneously generating heat energy and oscillation energy. In the method heat is generated by induction heating and oscillations are created by means of at least piezoelectric elements. Previously a resonance circuit formed by a series connection of an inductive component and a capacitive, piezoelectric component has been used for the generation of oscillations only. A disadvantage of this kind of circuit has been that the circuit is difficult to control on account of the narrow resonance region of the piezoelectric element. This advantage is avoided in the solution according to the invention in such manner that one and the same resonance circuit formed by a series connection of an inductive and capacitive element generates both heat energy and oscillation energy.