Alcatel N.v.

Alcatel Lucent

Alcatel

Alcatel Sel Aktiengesellschaft

Uwe Ackermann

Dieter Kopp

Thomas Hormann

Michael Walker

Hans Jurgen Matt

Bernhard Klotz

Susanne Dvorak

The invention concerns a method, a network element and a computer program product for monitoring the quality of a real-time communication () in a packet network () comprising at least two test points (). A packet stream pattern () is accessed and injected at a first test point (). After transmission of the packet stream pattern () through the packet network (), a degraded packet stream pattern () is received at a second test point (). Characteristics of the degraded packet stream pattern () are determined and compared with corresponding characteristics of the packet stream pattern () injected at the first test point (). Based on the comparison, data concerning quality degradation caused by transmission over the packet network () is evaluated.

Method of monitoring the quality of a realtime communication

Digital filters are used to compensate for echoes in a transmission system in which unwanted couplings occur between a signal value in the receiving direction and a signal value in the transmitting direction. The correct adjustment of the filter coefficients has a considerable influence on the achievable echo compensation. Disturbance signals such as background noises, nonlinear effects in A/D converters or an active local speaker can briefly change the adjustment of the filter coefficients in a way so that the digital filter does not compensate for the echoes and causes additional echoes in unfavorable cases. In accordance with the invention a set of filter coefficients (C(j)) are weighted with an envelope curve (H(j)) and an error measurement (F(j)) is determined therefrom. Depending on the magnitude of the error measurement (F(j)), the filter coefficients (ci) are used for further processing or are discarded. The pertinent arrangement comprises a first digital filter (1) for which the filter coefficients (ci) are continuously calculated in accordance with the NLMS algorithm. These filter coefficients (ci) are stored, weighted and the best values are used to adjust a second digital filter (7) whose output signal (9) is subtracted from the echo-affected signal, creating an echo-free output signal (10) and thus significantly increasing the quality of a natural and undisturbed transmission, even with short-time disturbances.

Method of adaptively adjusting the coefficients of a digital filter in

A method and an apparatus provide safe access control without the need for supplementary devices. By entering audible words or sounds during a playing of a text of a recorded announcement, a first personal access code based on both the audible uttering and the timing of the audible uttering is generated and stored for authorized users. Subsequently, a second personal access code is generated in the same way when access is sought by a subsequent user seeking access to the facility. The second personal access code is compared with the first personal access code. If the codes correspond in both terms of the audible uttering and the timing of the audible uttering, access is permitted. High security is provided which prevents unauthorized use. The apparatus has a low cost and a low complexity, because no supplementary devices are necessary.

Method and apparatus for access control based on an audible uttering and

A method of managing a speech memory (VMEM) and an assembly therefor are disclosed. To enable a plurality of users (U1, U2, U3, U4) to access the speech memory, the latter is divided into user memory areas (S1, S2, S3, S4) and a common memory area (SALL). By adding a portion (S4') of the common memory area (SALL) to one of the user memory areas (S4') or vice versa, the size of this user memory area is adapted to the memory space requirements (Min4) of the user (U4). The capacity of the speech memory (VMEM) is effectively utilized, since, as far as possible, no free memory space is assigned to the users (U1 to U4) which will not be used by them. The assembly can be used, for example, as a voice mailbox in a telecommunications system.

Method of managing a speech memory, and assembly therefor

A secondary computer is connected to a primary computer via a shared memory. The initial program loader for the secondary computer is stored in a mass memory of the primary computer rather than in a bootstrap memory. The primary computer loads the initial program loader into the shared memory, sends a restart instruction to a central processing unit of the secondary computer, and then controls a memory access logic circuit such that all program memory access instruction are routed to that portion of the shared memory holding the initial program loader until the secondary computer has read out the last instruction of the initial program loader. The central processing unit then sends to the memory access logic circuit an acknowledge signal which causes the latter to route all further program memory access instructions to a program memory of the secondary computer.

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Freiberg, Germany

Uwe Ackermann