A method and device is described for converting an STM-1 signal into a
sub-STM-1
signal in synchronous radio transmission. The invention provides for the use
of a pure regenerator network element without any multiplexing function. The method
according to the invention provides in transmission, for reducing the received
STM-1 signal by one third (only the first TUG-3 is considered as
valid and is transmitted in the radio link, whereas the second and the third TUG-3
are considered in an unequipped condition and are not transmitted), thus maintaining
the STM-1 structure. In reception, the method provides for reconstructing
the signal with the complete regenaration of the payload and the correct structure
of the AU-4 without incurring any parity control infringement.