Cselt-centro Studi E Laboratori Telecomunicazioni S.p.a.

Telecom Italia

Sip - Societa Italiana Per L-esercizio Delle Telecomunicazioni P.a.

Paolo Destefanis

Cesare Poggio

Gian B Alaria

Silvano Appiano

Claudio Benenti

Antonio Cavallaro

Piero Lovisolo

Andrea Scoscina

Alessandro Cama

The device essentially consists of an adapter having a centralized unit (5) tasked with manipulating ATM flows and managing access requests, and specialized modules (3.sub.1 . . . 3.sub.k . . . 3.sub.n) which allow direct access to the ATM network by, for instance, a satellite network or a service (2.sub.1 . . . 2.sub.k . . . 2.sub.n). The centralized unit (5) dynamically allocates the available band on the ATM network access resources according to the access requests by the interface towards the outside world, by handling individual requests as separate connections.

Interfacing device for ATM networks

The peripheral unit for multi-videoconferencing permits multi-videoconferencing while fully exploiting the characteristics of a telecommunications satellite, and can also provide the service to users not connected to the ground network. In particular, the system can connect several remote rooms through a satellite network, interfaceable with a ground control center, to provide an overall mixed ground-satellite network able to simultaneously serve both permanent and temporary users. The peripheral unit is connected on one side to the transceiving station for the satellite link and on the other to the encoder and decoder of video and audio signals, which are generated locally or received from a remote station and organized according to a protocol provided with time-slot frames and superframes.

Peripheral unit for satelite multi-videoconferencing

An interface facilitating data transmission between a control processor, connected to an asynchronous two-way bus, and a plurality of terminals, connected to a common synchronous two-way bus, comprises a microprocessor responsive to periodically recurring access requests from the several terminals. The access requests are short pulses with a recurrence period greatly exceeding their duration, this period being nominally equal for all terminals and sufficient to accommodate one data transfer to or from each terminal with time remaining for execution of part of a main program performed by the control processor. Coinciding access requests from different terminals are handled according to a predetermined order of priority. The exchange of data takes place by way of a data memory and a buffer memory linked by an internal two-way bus. Data transfer between the control processor and a terminal takes place in three stages, i.e. between the processor and the buffer memory, between the buffer memory and the data memory, and between the data memory and the terminal. Except during the second stage, the processor has always access to the buffer memory.

Interface controlling bidirectional data transfer between a synchronous

Television signals generated at a transmitting station are digitized and are then transformed into bit groups by a precoder reducing their information content by eliminating redundancies, as by comparing each pixel of a given frame with the homologous pixel of the immediately preceding frame and, upon detecting their equality, emitting a particular reduction code in lieu of an otherwise emitted luminance signal. A message encoder following the precoder generates outgoing data words which may comprise a luminance value accompanied by an integrity code, a changeover signal accompanied by a reduction code, a numerical value specifying the number of consecutive pixels remaining unchanged from the preceding frame, or a synchronizing code. The bits of the outgoing data words are serialized and are temporarily stored in a buffer register in order to be sent at regular intervals, via a communication channel, to a receiving station where a message decoder regroups them in their original order. The decoder separates the luminance data from the reduction codes under the control of a local clock, re-expands the reduced information and, after checking for transmission errors, converts the received data into luminosity signals designed to reproduce the original television picture.

Coding and decoding method and system for variable-length sequences of

An SS/TDMA communication system comprises a multiplicity of ground stations, including one master station and a number of traffic stations without control function, exchanging digitized voice or other message signals via a relay station aboard a satellite. Each ground station comprises base-band equipment including a transmitting section, a receiving section and a control unit. The control unit of the master station generates outgoing timing signals and processes incoming timing signals for synchronizing the operations of its own equipment and that of the traffic stations with the operation of a switching unit of the satellite-borne relay station; this control unit also emits routing instructions for that switching unit. The transmitting section of each ground station is served by an independent time base while its receiving section has a time base locked to the clock of the satellite; both time bases are adjustable by the associated control unit for correlation with the timing signals sent to and received back from the relay station.

Growing community of inventors

Turin, Italy

Paolo Destefanis