As access equipment such as cellular RAN Distributed Units become more critical to network operation there are increasing demands for improved availability, including extended local time holdover in the event of synchronization source failure. However, commercial pressures typically don’t allow the budget to provide this in traditional ways, so alternative novel solutions must be found. This paper shows how the latest generation of “smart” temperature compensated and controlled oscillators can be used in conjunction with the high precision measurement capabilities and fine resolution frequency control provided by modern digital phase locked loops, and advanced oscillator modeling software, to implement a robust compensation scheme enabling extended time holdover within budget.