Tone relay system and method

A tone relay method, comprising receiving a sequence of signal samples;

• providing tone detection meta-information for a plurality of cells of the received signal samples, a cell comprising one or more of said signal samples;
• providing a plurality of media descriptors, each media descriptor an instance of a data structure, wherein:
• a first component of the data structure comprises a cell of the plurality of cells;
• and a second component of the data structure comprises tone detection meta-information for said cell;
• performing an evaluation of said meta-information and modifying said meta-information when a result of said evaluation indicates an undetermined tone state;
• providing said cells with a predetermined delay to a tone aggregator module, when said meta-information indicates a tone, for transmission over a network, the providing with a predetermined delay comprising:
• storing the cells of received signal samples in a buffer;
• and inserting other cells comprising digital silence into the buffer prior to the cells of received signal samples;
• and providing said cells of the received signal samples without said predetermined time delay to an encoder module, for transmission over said network, otherwise, wherein:
• the performing the evaluation comprises confirming a start of a tone depending on a first duration (Ts) after an indicated start of said tone;
• and durations of the one or more signal samples of the cells of the media descriptors are less than the first duration Ts.

A voice over internet protocol (VoIP) transmission system, comprising:

• a tone detector arranged to receive a sequence of signal samples and to provide tone detection meta-information for a plurality of cells of the received signal samples, a cell comprising one or more of said signal samples;
• a tone aggregator module;
• an encoder module;
• and a tone relay module arranged to receive each cell, to perform an evaluation of said meta-information and modify said meta-information when a result of said evaluation indicates an undetermined tone state, to provide said cells with a predetermined delay to the tone aggregator module, when said meta-information indicates a tone, for transmission over a network, wherein:
• said tone relay module is arranged to confirm a start of said tone depending on a first duration (Ts) after an indicated start of said tone;
• durations of the one or more signal samples of the cells are less than the first duration Ts;
• and the providing with a predetermined delay comprises:
• storing the cells of received signal samples in a buffer;
• and inserting other cells comprising digital silence into the buffer prior to the cells of received signal samples;
• and to provide said cells of the received signal samples without said predetermined time delay to the encoder module, for transmission over said network, otherwise.