A system comprising: a plurality of transmitting subsystems (105-1...105-n), each of said plurality of transmitting subsystems (105-1...105-n) comprising a plurality of transmitters, each of said plurality of transmitters being configured to transmit an associated optical signal on an associated optical channel, each of said plurality of transmitting subsystems further comprising a multiplexer, the multiplexer being configured to combine the associated optical signals to provide an associated user-specific aggregate optical signal (113-1...113-n); at least one user control unit, UCU, (120, 120a, 120b-1...120b-n, 120c-1...120c-n, 120-1...120-n) coupled to at least one of said transmitting subsystems (105-1...105-n), said at least one UCU (120, 120a, 120b-1...120b-n, 120c-1...120c-n, 120-1...120-n) being configured to receive at least one of said user-specific aggregate optical signals (113-1...113-n) from said at least one of said transmitting subsystems (105-1...105-n) and provide at least one associated aggregate output signal comprising at least a portion of said at least one of said user-specific aggregate optical signals, said UCU (120, 120a, 120b-1...120b-n, 120c-1...120c-n, 120-1...120-n) being configured to dynamically adjust said at least one associated aggregate output signal to enforce at least one predetermined system policy, characterized in that said at least one predetermined system policy comprises a pre-determined user-allocated bandwidth associated with said at least one transmitting subsystem (105-1...105-n), the pre-determined user-allocated bandwidth comprising a plurality of optical channels, and wherein said UCU (120, 120a, 120b-1...120b-n, 120c-1...120c-n, 120-1...120-n) is configured to adjust said at least one associated aggregate output signal by limiting said at least one associated aggregate output signal to said pre-determined user-allocated bandwidth. a plurality of transmitting subsystems (105-1...105-n), each of said plurality of transmitting subsystems (105-1...105-n) comprising a plurality of transmitters, each of said plurality of transmitters being configured to transmit an associated optical signal on an associated optical channel, each of said plurality of transmitting subsystems further comprising a multiplexer, the multiplexer being configured to combine the associated optical signals to provide an associated user-specific aggregate optical signal (113-1...113-n); at least one user control unit, UCU, (120, 120a, 120b-1...120b-n, 120c-1...120c-n, 120-1...120-n) coupled to at least one of said transmitting subsystems (105-1...105-n), said at least one UCU (120, 120a, 120b-1...120b-n, 120c-1...120c-n, 120-1...120-n) being configured to receive at least one of said user-specific aggregate optical signals (113-1...113-n) from said at least one of said transmitting subsystems (105-1...105-n) and provide at least one associated aggregate output signal comprising at least a portion of said at least one of said user-specific aggregate optical signals, said UCU (120, 120a, 120b-1...120b-n, 120c-1...120c-n, 120-1...120-n) being configured to dynamically adjust said at least one associated aggregate output signal to enforce at least one predetermined system policy, characterized in that said at least one predetermined system policy comprises a pre-determined user-allocated bandwidth associated with said at least one transmitting subsystem (105-1...105-n), the pre-determined user-allocated bandwidth comprising a plurality of optical channels, and wherein said UCU (120, 120a, 120b-1...120b-n, 120c-1...120c-n, 120-1...120-n) is configured to adjust said at least one associated aggregate output signal by limiting said at least one associated aggregate output signal to said pre-determined user-allocated bandwidth.