Abstract: In a prepaid group service, a number of subscribers belonging to a group share one common prepaid group account. In order to minimize the risk of an improper call release, an undercut of the prepaid group account is determined (305) on the basis of at least one parameter; and the undercut is used when deciding (309) if a call, charged from the prepaid group account, can be set up or continued when there is at least another ongoing call which is charged from the prepaid group account.

Abstract: A method and system of offering wireless telecommunication services in a visited telecommunication network for a terminal device which does not have a first identifier accepted by the network. In the method, the visited network gives the terminal device a right to a temporary use of a telecommunication connection and establishes a connection with a third party in order to obtain a confirmation of paid services, for example. The third party checks a second identifier transmitted by the terminal device and transmits the confirmation to the visited network, which offers telecommunication services for the terminal device.

Abstract: A filter structure (1090, 1100, 1200) comprises a first piezoelectric resonator (1021a), whose resonance frequency is a first resonance frequency and which is connected to an input conductor (1030a, 1030b). In order to increase the power handling capacity of the filter structure, it comprises other piezoelectric resonators connected in series with the first piezoelectric resonator. In this plurality (1020, 1110, 1220) of piezoelectric resonators, each resonator has a resonance frequency substantially equal to the first resonance frequency. The plurality (1020, 1110, 1220) of piezoelectric resonators is connected to the rest of the filter structure only through the first piezoelectric resonator (1021a) at one end of said plurality and through a second piezoelectric resonator (1021b), which is at the other end said plurality. The impedance of said plurality is arranged to match the impedance level of the filter structure.

Abstract: Disclosed is an interface (10, 40) between a master device (30) and a slave device (20). The interface includes a bit serial bidirectional signal line (10A) for conveying commands and associated data from the master device to the slave device, and for conveying a reset signal, an interrupt signal, and a learning sequence signal for specifying a duration of a bit time for data transferred from the slave device to the master device. The bit serial bidirectional signal line further indicates an accessory device connected/disconnected state to the master device.

Abstract: The present invention relates to a method of changing a telecommunication channel in a mobile communication system for a given mobile station, which mobile station has a connection in progress, and the connection is provided with a channel on a radio connection between the mobile station and base station system and a telecommunication channel between the base station system and a mobile services switching center. In order to facilitate the changing of the telecommunication channel the method includes putting a new telecommunication channel between the mobile services switching center and the base station system, indicated by the handover message into use for the connection, and connecting the channel used to the new telecommunication channel in such a way that the radio channel remains unchanged irrespective of the change of the telecommunication channel.

Abstract: The invention relates to a linearization method for an RF amplifier and an arrangement implementing the method. A difference between an output signal of the amplifier and an unpredistorted input signal supplied to the amplifier is formed from baseband, quadrature components by means of a complex LMS algorithm in adaptation means. On the basis of the signal difference, the non-linearity of the amplifier is adaptively corrected before a quadrature modulator by changing the values of the complex quadrature components of the baseband signal by means of digital predistortion coefficients retrieved from a memory.

Abstract: A method for implementing a double-ended queue (deque) in a memory (MEM), and a memory arrangement. To be able to reduce the amount of copying, particularly in functional environments, the double-ended queue is used in the memory as a hierarchic data structure where on the highest level of hierarchy, there is a three-element node of whose elements one points to the buffer forming the front end of the queue and another to the buffer forming the tail end of the queue. The middle of the queue inlcudes nodes on different levels of hierarchy so that pointing from each level of hierarchy to the next lower level of hierarchy is done by a pointer in the third element of a three-element node. The pointer points to a node on the next lower level of hierarchy which is a similar three-element node, with the exception of the lowest level of hierarchy where the node can also be a buffer, and with the exception of the highest level of hierarchy, where the said pointer can also be a NIL pointer.

Abstract: An Explicit Congestion Notification (ECN) method is disclosed for wireless applications to avoid network congestion in a TCP/IP packet-switched network. Such method comprises transmitting, at a source node, data packets to a destination node, via at least an intermediate node; determining, at the intermediate node, if an incipient congestion is encountered, setting a Congestion Experienced (CE) flag in each data packet to notify congestion; sending, at the destination node, an ECN-Echo acknowledgment packet back to the source node to inform congestion; reducing, at the source node, a congestion window and a transmission rate to avoid congestion; if the packet loss is due to congestion, re-transmitting, at the source node, only a lost packet to the destination node; alternatively, if the packet loss is due to transmission error, re-transmitting, the lost packet to the destination node, while increasing a round-trip timeout but maintaining the same congestion window.

Abstract: A mobile communication system that proposes a new charging principle, according to which the roaming leg is paid entirely by the party who forwards the call to a mobile subscriber. In an exemplary embodiment, the call is first routed to the exchange of subscriber B, who has forwarded his calls. After determining that the call is to be forwarded to a mobile subscriber C, the exchange routes the call to the gateway mobile switching center (GMSC) capable of making interrogations to the home location register of subscriber C. When the charging record for the call is generated, the called subscriber B is charged for the leg between the GMSC and subscriber C. Thus, subscriber C does not have to pay for calls addressed to subscriber B. To minimize the call costs to subscriber B, as direct a route as possible is preferably used on the leg between the GMSC and subscriber C.

Abstract: In combined systems of different radio systems, for example in a combined system of the radio access network (RAN) of the IMT-2000 system and the core network (MSC) of the GSM system, a problem exists in transferring encryption settings from a system element to the others. The present invention relates to a method of setting encryption for a connection in such a combined system, where the handling of the encryption settings of the switching centre (MSC) and the base station (BTS) of the radio network is carried out at different protocol layers than the handling of the encryption settings of the mobile terminals (MT). In the method, encryption is arranged for the connection between the radio access network (RAN) and the mobile terminal (MT), and an encryption setting is transmitted from the switching centre (MSC) to the control unit (BSC) of the radio access network (RAN).

Abstract: The invention relates to a method and arrangement by means of which a mobile station (MS, 400) operating in a cellular network measures and indicates the field strength of a signal sent by a base station (BTS, 451). From the measured signal it is calculated a virtual field strength (Pvr) on the basis of which it is determined whether the desired service (speech, data, GPRS, HSCSD) can be used at that field strength.

Abstract: An automatic frequency control (AFC) loop circuit (1A, 1B) includes a mixer (2) for mixing a local oscillator signal (3) with a received signal to generate a result signal; a frequency detector (5) coupled to the result signal and outputting a loop error signal; a combiner circuit (9) for combining error signals output from a plurality of fingers (12, 14, 16) of a rake receiver (220) with the loop error signal output from the frequency detector to generate a combined loop error signal; a sign detector (10) having an input coupled to an output of said combiner circuit for outputting a sign detector output signal for indicating a sign of the combined loop error signal; control circuitry (7, 8) for controlling a frequency of the local oscillator signal in accordance with the sign detector output signal and a loop filter (6) partitioned into a first loop filter (6A) coupled between the output of the frequency detector and an input to the sign detector, and a second loop filter (6B) coupled between an output of th

Abstract: A method, and associated apparatus, for a sending station operable in a communication system, such as a cellular communication system. A codeword is formed which, when transmitted upon a channel, exhibits a selective level of space and time diversity. A TCM (Trellis Coded Modulation) scheme is provided for a multiple-antenna transmitter which accommodates transmit diversity by way of the multiple antennas without requiring the need to utilize multiple Trellis Coded Modulation techniques.