Optical system for connecting subscriber units to the switching centre of a telecommunications network providing interactive and non-interactive services

Claim 1

Optical system for connecting customer premises networks to an exchange (EX) of a telecommunication network providing interactive and non-interactive services, said exchange comprising a connection network (CN), a connection network control unit (CU) and exchange termination equipments (ETE), each exchange termination equipment comprising an optical sender (23) and an optical receiver (26) tuned to the same wavelength, different for each exchange termination equipment, each customer premises network (CPN) comprising an optical sender (11) and an optical receiver (3, 5) tuned to the same wavelength which is variable, the wavelength of the receiver being set to the wavelength (Lc) of a control exchange termination equipment when the customer premises network is not communicating with an interactive service, the system comprising: an optical distribution network (DN) connecting all exchange termination equipment optical senders to all customer premises network optical receivers and connecting all customer premises network optical senders to all exchange termination equipment optical receivers, a control unit (CU) for assigning a different wavelength to each customer premises network communicating at a given time, said wavelength corresponding to an available exchange termination equipment which is not the control exchange termination equipment, characterised in that: the non-interactive services (SD, CY) are connected (C1 ..., C4) to the control exchange termination equipment (ETE0) to send non-interactive service signals at the control exchange termination equipment wavelength (Lc), each customer premises network comprises means (1, 10) for requesting the control unit (CU) of the connection network (CN) to connect (C5) an exchange termination equipment (ETE31) via which said installation is already in communication with an interactive service to at least one non-interactive service (CY, SD) to send at the wavelength of said exchange termination equipment (ETE31) signals of at least one non-interactive service in parallel with the call already set up and means (1, 10) for receiving said signals, and each customer premises network comprises means (1, 10) for further receiving signals of at least one non-interactive service sent at the control exchange termination equipment wavelength (Lc) when said customer premises network is not communicating with an interactive service.