Abstract: A packet forwarding unit such as a Digital Subscriber Line Access Multiplexer (DSLAM) receives Ethernet packets carrying real-time information and forwards the information therein on output lines such as Asymmetric Digital Subscriber Lines (ADSLs). The DSLAM includes a clock device having an extraction unit and an adaptive clock. The extraction unit analyzes received packets to select streams of received packets from one destination to one user, and the adaptive clock generates a reference clock signal according to the arrival times of packets in the selected streams. The clock signal is sent to time reference units in DSL modems for the output lines.

Abstract: A forwarding unit such as a DSLAM (8) receives (21) Ethernet packets and forwards information therein on digital subscriber lines (27). For forwarding voice information of received Ethernet packets a reference clock signal is generated by a clock device (28) and provided to modems (23) for the digital subscriber lines. The clock device includes an extraction unit (29) for selecting at least one stream of received Ethernet packets, and a clock signal generating unit, configured as an adaptive clock unit (31), for generating a reference clock signal according to arrival times of packet in selected packet stream or streams. The reference clock signal can be provided to time reference units (25) in the modems. The extraction unit can analyze received Ethernet packets to find streams of packets from one destination to one user, the packets of each of the streams carrying real time information belonging to a real time service and then select one or more streams to be used by the adaptive clock unit.

Abstract: The present invention relates to a fuse-relay including a first pole (1, 11, 21, 31, 81) and a second pole (2, 12, 22, 32, 82). According to the invention the fuse-relay includes a resilient device (5, 18, 27, 37, 87) that is held in an elastically deformed position by a fuse (6, 16, 26, 36, 86) when the fuse (6, 16, 26, 36, 86) is whole; and in that the resilient device (5, 18, 27, 37, 87) is arranged to make or break a connection between the first pole (1, 11, 21, 31, 81) and the second pole (2, 12, 22, 32, 82) when the fuse (6, 16, 26, 36, 86) is blown. The invention also relates to a cross-connect with such fuse-relays, to a telecommunication system with such cross-connects and to a connection method.

Abstract: The present invention relates to a fuse-relay including a first pole (1, 11, 21, 31, 81) and a second pole (2, 12, 22, 32, 82). According to the invention the fuse-relay includes a resilient device (5, 18, 27, 37, 87) that is held in an elastically deformed position by a fuse (6, 16, 26, 36, 86) when the fuse (6, 16, 26, 36, 86) is whole; and in that the resilient device (5, 18, 27, 37, 87) is arranged to make or break a connection between the first pole (1, 11, 21, 31, 81) and the second pole (2, 12, 22, 32, 82) when the fuse (6, 16, 26, 36, 86) is blown. The invention also relates to a cross-connect with such fuse-relays, to a telecommunication system with such cross-connects and to a connection method.

Abstract: A method and arrangement are proposed for compensating intersymbol interference (ISI) in a multicarrier transmission system. Compensation is based on the generation of an estimate of the ISI tail and subtracting the estimate from the received signal. This is achieved by determining an estimate of the transmitted symbols at the receiver by filtering with a transfer function that approximates the inverse of the channel transfer function for the carrier frequencies used. Estimated of two consecutively transmitted symbols are used to generate a difference symbol. When a string of zeroes is appended to this difference symbol and passed through a filter, a transient results which is equivalent to that generated by the consecutively transmitted symbols passed over the channel.

Abstract: A method and arrangement are proposed for compensating for intersymbol interference (ISI) in a multi-carrier transmission system. Compensation is based on the generation of an estimate of the ISI transient tail generated between consecutively transmitted symbols and subtracting this tail from the received signals. Each symbol includes a cyclic extension as prefix. The tail is generated from a tail portion isolated from the cyclic prefix. This tail portion is then used in a filter arrangement adapted to generate at least an estimate of the full transient signal. The filter function may be proceeded by a processing module for generating the initial conditions of the filter function from the transient signal portion. The full transient is then generated by inputting a predetermined value into the filter function. The processing module may be a second filter or processing arrangement adapted to perform calculations.

Abstract: A predistorter, a method for predistorting, and an amplifier include a predistorter. The predistorter is particularly suitable for predistorting an input signal of an amplifier, which amplifier introduces frequency dependent distortion that increase with the frequency. The predistorter makes use of a predistortion technique involving a high pass filter such that distortion, which compensates for the distortion introduced by the amplifier, is introduced in an output signal of the predistorter for the specific frequencies for which further distortion compensation is required. An advantage is that the predistorter allows the performance of an amplifier to be improved by reducing distortion and increasing linearity. Thereby the predistorter allows low power amplifiers with relaxed distortion requirements to be used as, for example, line drivers in many telecommunications systems.

Abstract: A line driver supplied with a power supply voltage from a power supply uses whole or part of the power supply voltage to generate the output voltage if the input voltage is within a predefined range; loads at least one capacitor with at least one capacitor voltage; and uses whole or part of the at least one capacitor voltage in addition to whole or part of the power supply voltage to generate the output voltage if the input voltage is outside the predefined range.

Abstract: A predistorter, a method for predistorting, and an amplifier include a predistorter. The predistorter is particularly suitable for predistorting an input signal of an amplifier, which amplifier introduces frequency dependent distortion that increase with the frequency. The predistorter makes use of a predistortion technique involving a high pass filter such that distortion, which compensates for the distortion introduced by the amplifier, is introduced in an output signal of the predistorter for the specific frequencies for which further distortion compensation is required. An advantage is that the predistorter allows the performance of an amplifier to be improved by reducing distortion and increasing linearity. Thereby the predistorter allows low power amplifiers with relaxed distortion requirements to be used as, for example, line drivers in many telecommunications systems.

Abstract: To minimize power dissipation in a line driver (3) in a central office (CO) for driving a DSL connection to a network terminal (NT) with a predetermined maximum constellation size, the central office (CO) supplies the line driver (3) with a predetermined supply voltage during a training sequence, and transfers data with a predetermined power spectral density in all available channels. The network terminal (NT) measures the signal-to-noise ratio of each channel, and transfers information to the central office (CO) about channels having signal-to-noise ratios that enable transfer of data.

Abstract: The invention relates to a line driver supplied with a power supply voltage from a power supply and an amplifying method. According to the invention the following steps are performed: using whole or part of the power supply voltage to generate the output voltage if the input voltage is within the predefined range; loading at least one capacitor with at least one capacitor voltage; and using whole or part of the capacitor voltage in addition to whole or part of the power supply voltage to generate the output voltage if the input voltage is outside the predefined range.

Abstract: A method and apparatus are provided for reducing power dissipated by an amplifier circuit such as a line driver in a Digital Subscriber Line (DSL), a power amplifier in a radio environment, etc. The power supplied to the amplifier circuit changes depending upon the level of input signal to the amplifier circuit. A higher power is supplied to the amplifier circuit when the level of the input signal exceeds a threshold. Otherwise, a lower power is supplied to the amplifier circuit.