Abstract: The invention relates to an optical add/drop device comprising at least two optical filter units (OADE). An individual filter unit comprises a first, second and third port so that when all signals of the aggregate signal are present at the first port (A), said desired signal is present at the second port (B) and all other signals except the desired signal are present at the third port (C). To provide flexible altering possibilities, a number of filter units (OADDE . . . OADE) are placed in succession to form at least two pairs of filter units in such a way that in each pair the first filter unit operates at a given wavelength as a signal dropping unit and the second as an adding unit corresponding to the first unit, adding to the aggregate signal a signal having the same wavelength.

Abstract: A seal attached to a door frame for mating engagement with a door. The seal including a first side for sealing engagement with a door edge, and a second side for sealing engagement with the door outer surface. The seal moves relative to the door from the door open position, where the seal first side is disposed at a first spaced apart distance from the door frame edge surface; to the door closed position, where the door moves the seal first side closer to the door frame edge surface. The seal further moves relative to the door from the door open position, where the seal second side is not disposed adjacent to the door outer surface; to the door closed position where the seal second side is disposed adjacent to the door outer surface and in covering relation to the door outer surface.

Abstract: The invention is based on the idea that wavelength of a laser transmitter in a WDM system can be changed in a controlled fashion by inducing an accurately pre-defined change in the cooler control current TEC. This, in turn, effects a controlled change in the heating or cooling operation of the cooler. As a result, a predetermined change takes place in the wavelength of the light generated by the laser. The temperature control circuit ensures that the laser temperature and, thus, wavelength, are maintained exactly at the new value. For each desired wavelength, a parameter set consisting of a pre-set laser temperature value, a laser power value and laser modulation bias values has been saved in storage in advance. When the laser wavelength is to be changed, the parameter values corresponding to the wavelength are retrieved from the storage and fed to the laser. Retrieval and feeding can be pre-programmed or carried out manually.

Abstract: In a mobile speech communication system including a base station having a data connection to a mobile services switching center through a transcoder unit, where the data connection includes a circuit-switched data transmission connection between the base station and transcoder unit to exchange speech parameters transmitted as TRAU frames, the data connection also being partly composed of a packet-switched data transmission connection to improve the data transmission connection, a converter is arranged on the data transmission connection between the base station and the transcoder unit for converting a TRAU frame received from the circuit-switched data transmission connection into a packet to be transmitted over the packet-switched connection, wherein the conversion includes a removal of bits included in the TRAU frame which are not needed on the packet-switched connection.

Abstract: The invention relates to a circuit arrangement for forming an impedance match of transmission lines. The circuit arrangement includes a control state (11), a dynamic input impedance formed by resistances and a transformer (13) provided with primary and secondary coils. The control stage (11) and the input impedance are connected to the poles of the transformer's (13) secondary coil, and transmission lines having mutually different characteristic impedances are connected one at a time to the poles of the transformer's (13) primary coil. According to the invention, the circuit arrangement is characterised in that for forming a resistive input impedance the circuit arrangement includes a processor (15) and means (14) for implementing the match.

Abstract: The invention relates to a transmission method and a radio system comprising a base transceiver station acting as a transceiver and subscriber terminals acting as transceivers which establish a connection with each other with a signal transmitted through the base transceiver station, for which connection a radio channel is formed, in which a signal coded by the transceiver is transmitted. The transceiver comprises transmission means which transmit frames when the transceiver is in DTX mode. The radio system comprises measuring means which measure the signal received by the transceiver from the radio channel, and transmission means which during DTX transmit information in frames on the basis of the measurement result obtained from the measuring means, of which frames at least some are freely placed by the transmission means anywhere in the frame structure to be transmitted.

Abstract: A power amplifier to process an input signal includes an amplifying device operating at a quiescent point and a bias network that varies the quiescent point according to a frequency of the input signal. In a variant of this power amplifier, the bias network includes a compensation circuit to provide a bias signal that varies according to a frequency of the input signal and a bias circuit to vary the quiescent point according to the bias signal. In an alternative embodiment of the invention, a method of making a power amplifier includes steps of measuring a gain performance of an amplifying device at a plurality of frequencies, determining a desired quiescent point of the amplifying device at each frequency of the plurality of frequencies, and constructing a bias network that varies an operating quiescent point of the amplifying device according to a frequency of the input signal so that the operating quiescent point approximates the desired quiescent point at each frequency of the plurality of frequencies.

Abstract: The invention is a method of relocating of header compression/decompression functions between a plurality of network entities and mobile compressors and/or mobile decompressors.

Abstract: The present invention relates to a wireless local loop. In particular, the present invention relates to a procedure for limiting the mobility area of a terminal device in a wireless local loop environment. According to the invention, the mobility area (MOA) for the terminal device (5) is defined as a specified geographic area comprising the coverage area of at least one cell (4), and the locking of the terminal device with the local loop and/or channel change by the terminal device is inhibited if the cell from which the terminal device is trying to get locked or to whose channel it is trying to change is outside the mobility area.

Abstract: A method and apparatus for estimating separate channel frequency responses for two channels in an orthogonal frequency division multiplexing system with two transmitters is disclosed. The channel frequency responses are estimated using specifically selected training symbols that are broadcast from the two transmitters. The training symbols are specifically selected so as to improve the estimation of the channel frequency responses for each channel, while requiring the same amount of training symbols as in an estimation of the channel frequency response of a single channel.

Abstract: A method for manufacturing a SIL hybrid circuit is presented. A lead frame is provided which includes side bands and clip members between the side bands configured to connectively receive a hybrid circuit. The lead frame further includes foot members between the side bands configured to be surface-mounted to a base substrate. Each foot member has tabs at the ends thereof and support members extending straight from the tabs to connect the tabs to the side bands. Corresponding contact areas of the hybrid circuit are attached to the clip members. At least one foot member and associated support members are selected to remain in the lead frame to support the SIL hybrid circuit during positioning on the base substrate and surface mounting thereto. Excess parts are removed from the lead frame based on the selecting. As such, SIL hybrid circuits may be efficiently used to achieve high packaging densities.

Abstract: The present invention is based on the idea that the base transceiver station can make a decision as to changing transmission diversity in response to the power control message sent by the mobile station. The decision to change transmission diversity is made, for instance, on the basis of the result obtained from filtering the power control requests. For example, filtering can be carried out using a sliding window that contains power control information on the basis of which the decision is made. It is not necessary for the mobile station to transmit a special request to change transmission diversity; instead, the decision on changing transmission diversity is made by the base transceiver station in response to the power control information that the mobile station would, in any case, send to the base transceiver station.

Abstract: A method and an equipment implementing the method in a mobile communication system in which short messages may be sent amid actual signalling, whereby one of more short message service centers providing short message services are linked to the mobile communication system. An identifier supplied by the subscriber and associated with the desired service is included in a mobile originated short message. On the basis of this identifier a database search is performed in a database connected with the mobile communication system, the database comprising identifiers associated with short message services available to subscribers and related routing information. The message is sent to the routing address obtained on the basis of the database search. A short message submitted by a subscriber may thus be routed to the desired short message service center without the subscriber having to directly attend to the routing.

Abstract: The invention relates to protection of an optical transmission connection. From the transmitting end of the connection, the same optical signal is transmitted along a first path and a second path to the receiving end, where the power level of the signal received from each path is monitored, and one of the paths is selected as the working path and the signal arriving from the said path is connected to the receiver, whereby the other path remains as a redundancy path. For the transmission connection to preserve an optimum performance also when the power level difference between the paths is varying, that path is at each time selected as the working path, where the received signal is considered at the moment in question to have the higher power level. The selection is always carried out when the power level difference between the signals reaches a predetermined threshold value, irrespective of the power level of the signal received at that time from the working path.

Abstract: Procedure for connecting a subscriber to a telephone exchange in a data communication system comprising a telephone exchange (LE) with a number of subscribers defined in it, an access network (AN) connected to the telephone exchange via a first V5 interface (V5) and comprising a first access node (AN1), a second access node (AN2), which is connected to the telephone exchange, and a subscriber terminal (TE), which is connected to the local exchange via the access network and/or a concentrator. According to the invention, the second access node (AN2) is connected to the first access node (AN1) via a second V5 interface, the connection between the subscriber and the telephone exchange (LE) being this set up by cascading two V5 interfaces.

Abstract: Provided is a method and system for performing a handover of a terminal subscriber between sub-cells in a cellular radio network base station. In the method and system, signals from antenna units corresponding to each of the sub-cells are added together to form a combined signal. A signal power of the combined signal and the signal power a signal from a serving sub-cell are measured in a transceiver of the base station. The measurement results are compared. If the signal power of the combined signal is greater than the signal power of the signal from the serving sub-cell, a handover of the terminal subscriber is performed.

Abstract: The invention relates to a Rake receiver of a CDMA system using IRC. The Rake receiver comprises at least two antenna branches, at least one Rake finger, and a delay estimator. The delay estimator comprises a despreader and an allocator for selecting at least one delay, and allocating a Rake finger for processing the signal component found by informing the Rake finger of the delay found. The delay estimator further comprises: a channel estimator, an interference estimator for generating an interference signal, a weighting coefficient part for providing each antenna branch with weighting coefficients maximizing the Signal-to-Interference-and-Noise Ratio, a multiplier for multiplying the pilot part by a weighting coefficient, and an antenna branch summer for combining the despread pilot parts, received via the separate antenna branches and multiplied by the weighting coefficient, to one combined pilot signal, on which combined pilot signal the selection is based in the allocator.

Abstract: The objective of the invention is to increase the potential hop density of single frequency TDD radio links by allowing a set of closely located terminals to use a single channel. This is possible when transmission and reception periods of the terminals are synchronized so that the transmit period of any of the terminals in a terminal group does not overlap with the receive period of any of the terminals in the group. Synchronization is achieved by selecting at least one terminal in a hub site as a super master terminal. This terminal gives timing through a common bus to the rest of the terminals in the group. These terminals use the received timing for adjusting their own timing i.e. for adjusting the starting moment and ending moment of the transmission and reception periods in such a manner that none of terminals is sending a burst while another terminal is receiving.

Abstract: The invention relates to a procedure for carrying out checking functions relating to safety management in a mobile communication network and/or in a wireless local network during call setup. In the procedure, information about the degree of occupancy of a data processing apparatus implementing the checking functions in a network element, such as a mobile communication switching center and/or the access node of a wireless local network, is continuously determined, the frequency of execution of the checking functions is adjusted based on the occupancy information thus determined, and checking functions are carried out on the calls according to the checking frequency defined for the respective degree of occupancy.

Abstract: Subscriber terminal units (TU) are connected over a wireless link via a base station (BS) to an access node (AN) and further from the access node to a local exchange (LE) via a standard V5.2 interface, in which, when the interface is congested and a subscriber (TU) connected to the access node (AN) is attempting to make an emergency call to a public emergency number, the call control system of the local exchange (LE) cannot at once find a free time slot for the setup of the emergency call. In the procedure, call setup requests for other than emergency calls over the V5.2 interface are disabled during a predetermined period of time t2, and attempts to allocate a time slot in the V5.2 interface for the emergency call are repeated during such predetermined period of time t2.