Motorola Corporation

Adtran Gmbh

Robert Victor Holland

Wesley Stuart Jones

Timothy R Cotton

Garth D Hillman

John E Lane

John Timothy Pearson

Patrick K Kelly

A query message-based call routing mechanism for a limited access cooperative telecommunication network initially determines whether the called party is commonly located at the same node as the calling party. If not, the calling party node broadcasts a query message to all other nodes in the network to locate the called party. Only the node having local knowledge of the called extension will reply to the query message. Once the node sourcing the query message has received this reply message, it will place a call to the node servicing the called extension.

Query-based call routing mechanism for multinode cooperative telecommunication network

An Internet Protocol telephone system and method uses a telephone ( ) to place and receive voice over Internet Protocol (VoIP)-based telephone calls and public switched telephone network (PSTN)-based telephone calls. An off-hook condition with the telephone ( ) is detected and a sequence of signals generated by the telephone ( ) is received. At least a first signal generated by the telephone ( ) is buffered while the system attempts to detect a predetermined signal that signifies a VoIP-based call. Upon detection of the predetermined signal, the system intercepts subsequent signals in the sequence, absent the at least first signal that was buffered, and places the VoIP-based call via an internet ( ). Otherwise, the system places the PSTN-based call via a PSTN ( ).

Voice over internet protocol telephone system and method

A speakerphone system ( ) implements automatic gain control (AGC) when it is in a talk mode. While in the talk mode, the speakerphone system ( ) applies a gain factor determined by conventional AGC techniques. The inverse of this gain factor is applied to the received signal to avoid the need to adapt the coefficients of an echo canceller, such as an acoustic echo canceller (AEC) ( ), as the volume level changes. The speakerphone system ( ) determines whether it is in the talk, double-talk, or listen mode by adaptively changing energy thresholds which define these modes, in dependence on the distribution of ratios of the transmitted energy to received energy. The speakerphone system ( ) also varies a loop gain in dependence on the separation between the distribution of energy ratios in the talk mode and in the receive mode. This automatic loop gain adjustment ensures loop stability.

Method and apparatus for controlling a full-duplex communication system

An Internet Protocol telephone system and method uses a telephone (26) to place and receive voice over Internet Protocol (VoIP)-based telephone calls and public switched telephone network (PSTN)-based telephone calls. An off-hook condition with the telephone (26) is detected and a sequence of signals generated by the telephone (26) is received. At least a first signal generated by the telephone (26) is buffered while the system attempts to detect a predetermined signal that signifies a VoIP-based call. Upon detection of the predetermined signal, the system intercepts subsequent signals in the sequence, absent the at least first signal that was buffered, and places the VoIP-based call via an internet (12). Otherwise, the system places the PSTN-based call via a PSTN (16).

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Madison, AL, United States of America

Robert Victor Holland