Secondary master oscillator as a second class of digital network synchronization equipment is intended for tracing of several external timing reference signals coming from network, filtering of these signals, restoring their purity and quality, forming synchronization signals 2048 kHz or 2048 kbps for telecommunication equipment.
Secondary master oscillator contains:
- signal Synchronization Unit (SSU) - HP 55400A;
- rubidium Primary Reference Source VCH-311C disciplined by GPS/GLONASS.
Secondary master oscillator VCH-002 characteristics completely meet the requirements of ITU-T G.812. In addition to this, Rubidium PRS VCH-311C, disciplined by GPS/GLONASS, with the frequency accuracy better than 5x10-12, can be used as a reserve timing source that meets the requirements of the first class synchronization equipment ITU-T G.811.
The HP 55400A Network Synchronization Unit (Smart SSU) is specially designed by Hewlett - Packard to provide the best timing at SDH network. It has E1 and T1 signals inputs. Smart SSU is a modular, fully redundant timing distribution system for 2048 kbps primary rate networks. The unit tracks incoming timing references, qualifies the signals against network timing standards, then filters and distributes precise timing to all equipment in the node. Incoming reference signals may come from quantum frequency standards, GPS reference sources, or E1 signals. Smart SSU meets ETSI and ITU-T synchronization standards and provides holdover that exceeds the requirement for stratum-2 transit and local node performance. Smart SSU has a vast memory of up to 1000 events.
If jitter, excessive pointer adjustments, operator errors, frequency standard failure or transmission problems in the network occur, the unique system HP 55400A provides insurance from slips switching over to the reserve inputs.
Number of outputs reference signals 2048 kHz/kbps: 16 – 80.
Output signals protection: 1:1.
- in the Lock mode: <5x10-12;
- in the Holdover mode: <1x10-10.
Expecting VCH-002 lifetime: 20 years.