Zarlink Semiconductor introduced a DPLL (digital phase locked loop) for optical line cards operating at rates up to OC-3/STM-1. The DPLL device addresses dense line card "real estate" constraints and may be used in combination with Zarlink's family of analog PLLs to provide an end-to-end timing and synchronization solution for higher-speed SONET/SDH networking equipment. http://www.zarlink.com