Submarine Systems International has signed a $17.6 million deal with Brazil's state-owned oil company, Petroleo Brasileiro S.A., to provide the first undersea fiber optic cable network for offshore oil platforms. The network will consist of 475 km of fiber optic cable connecting Petroleo's fixed and floating platforms in the Campos Basin region of the south Atlantic. Targeted for service in June 1998, the system will replace the existing microwave, radio or satellite communications now in place for relaying information between oil platforms. The new fiber optic system will increase bandwidth tenfold and transmit voice, data and video at speeds from 155 to 622 Mb/s. The system can be upgraded to 2.5 Gb/s. Offshore oil platform.