Telecommunications Radioelectriques Et Telephoniques T.r.t.

Alcatel

Michel Coudreuse

Georges Bonnerot

Daniel Lecomte

Maurice Georges Bellanger

Patrice Senn

A calling telephone terminal and a called telephone terminal optimize the cost reduction of real time communication via a first communication network operating in real time. The calling terminal recognizes the status of a called terminal as &ldquo;real time communication&rdquo; in the case of a called terminal requiring real time communication or &ldquo;off-line communication&rdquo; in the case of a called terminal tolerating off-line communications and constructs and temporarily stores a message off-line and then sends it to the called terminal via a second communication network operating off-line if the status of the called terminal is &ldquo;off-line communication&rdquo;. The called terminal sends a &ldquo;real time communication&rdquo; or &ldquo;off-line communication&rdquo; status signal to a calling terminal in response to detection of an incoming call and receives and optionally stores a message sent by the calling terminal via a second communication network operating off-line if the status of the called terminal is &ldquo;off-line communication&rdquo;.

Telephone terminal and method of telephone communication between a calling terminal and a called terminal for optimizing a cost reduction of calls

To supervise the operation of an arithmetic unit of a digital transmultiplexer intended to convert a TDM-signal into a FDM-signal and vice versa, a pilot signal is utilized as the test signal which pilot signal is also used to control the level of the received FDM-signals and is processed in the transmultiplexer. The pilot signal selection filter used for controlling the level is used, also in time-division multiplex, for selecting a component having a frequency equal to the pilot signal frequency and occurring in each of the two input and output signals of the arithmetic unit.

Device for supervising a transmultiplexer

A circuit for converting into an FDM format spatially separated signalling signals and pilot signals, comprises a digital filter bank for converting the signals into the FDM format. A receiver for separating the signalling signals and pilot signals from the FDM signal comprises another digital filter bank for producing baseband signals. These filter banks have a transfer characteristic formed by a number of passband curves which are derived from the characteristic of a selected low-pass filter.

Growing community of inventors

Paris, France

Michel Coudreuse