The Nokia 472579A.101 850nm optical transceiver supports high speed serial links over multimode optical fiber at signaling rates for wireless base station applications involving the OBSAI or CPRI protocols, as well as related applications. The Transceiver is compliant with SFF-8431 and SFF-8432 for electrical and mechanical specifications. The transmitter converts serial CML electrical data into serial optical data. An open collector compatible Transmit Disable (Tx_Dis) is provided. When TX_DIS is asserted High, Transmitter is turned off. The receiver converts serial optical data into serial CML electrical data. An open collector compatible Loss of Signal is provided. The RX_LOS signal indicates insufficient optical power for reliable signal reception at the receiver. Digital diagnostics functions are available via a 2-wire serial interface, as specified in SFF-8472