Nortel Networks Corporation

Rockstar Bidco, LP

Matra

Kapsch Carriercom France S.a.s.

William Navarro

Rafi Rabipour

Paul Boudreaux

Pierre Gendron

Paul Vincent Coverdale

Chung Cheung C Chu

Paul Mermelstein

Chung Cheung Chu

Michel Mauc

Data communication apparatus including a port and a control entity. The control entity is operative to establish a connection with a remote entity over a first path and negotiate with the remote entity using in-band signaling over the first path establishment of a second path allowing the exchange of data between the data communication apparatus and the remote entity. The invention presents advantages from the standpoint of ease of implementation and bandwidth and resource savings. The use of an in-band messaging protocol to negotiate a establishment of the second path can be implemented generally in a straight forward manner. At the same time, the ability to transfer at least part of the connection to the second path avoids the drawbacks that would arise if that part of the connection were constrained to the first path. This feature allows the operator to take advantage of benefits provided by the second path but not available to the first path.

Methods and apparatus for data communication

A data communication apparatus, comprising an interface for enabling communication with a remote entity via a network and a control entity in communication with said interface. The control entity is operative to establish a packet-switched connection with the remote entity through the network and to negotiate with the remote entity using in-band signaling entry into a codec-bypass mode of operation. In this way, a codec-bypass connection, which enhances speech quality, can be established over a packet network, which reduces bandwidth.

This invention relates to a method and an apparatus for processing digital audio signals that may reduce the signal degradation occurring when the signal is exchanged between two communication terminals equipped with vocoders in a communication network. The solution proposed by this invention is to provide a communication terminal with a vocoder including a decoder section provided with a plurality of decoding units. A switch activates a selected one of the decoding units in dependence of the format of the compressed audio signal data frames received from a remote communication terminal. This system allows the communication terminal to support a number of different speech compression formals. In order to achieve simplicity and low cost, the communication terminal is provided with a single encoding unit. This results in an asymmetric arrangement where the communication terminal has a large number of decoding units than encoding units. The great majority of the speech compression algorithms deployed in wireless and Internet telephony standards have the property that their speech decoders are of far less computational complexity than their respective speech encoder. Therefore, a low-cost terminal can be produced which supports a low complexity speech encoder unit and a variety of speech decoder units.

Method and apparatus for asymmetric communication of compressed speech

In recent years, the telecommunications industry has witnessed the proliferation of a variety of digital vocoders in order to meet bandwidth demands of different wireline and wireless communication systems. The rapid growth in the diversity of networks and the number of users of such networks is increasing the number of instances where two vocoders are placed in tandem to serve a single connection. Such arrangements of low bit-rate codecs can degrade the quality of the transmitted speech. To overcome this problem the invention provides a novel method and an apparatus for transmitting digitized voice signals in the wireless communications environment. The apparatus is capable of converting a compressed speech signal from one format to another format via an intermediate common format, thus avoiding the necessity to successively de-compress voice data to a PCM type digitization and then recompress the voice data.

Method and apparatus for improving the voice quality of tandemed vocoders

Speech coding method using synthesis analysis using iterative

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Velizy-Villacoublay, France

William Navarro