Time　synchronization　is　a　critical　requirement　in　sixth-generation　(6G)　communication　systems　and　Internet　of　Things　(IoT)　applications.　However,　the　standard　timing　services　provided　by　global　navigation　satellite　systems　(GNSS)　are　increasingly　unable　to　meet　the　growing　demands　for　precision　and　stability　in　modern　networks.　The　proposed　system　leverages　a　single-difference　time　transfer　(SDPT)　method　to　achieve　tens　of　picoseconds　precision,　enabling　effective　clock　disciplining　for　oven-controlled　crystal　oscillators　(OCXO).　A　clock　disciplining　within　a　phase-locked　loop　(PLL)　structure　further　optimizes　the　output　of　time　and　frequency　signals,　enhancing　OCXO　stability.　Additionally,　a　differential　precise　time　synchronization　system　(DPTSS)　by　BeiDou　navigation　satellite　system　(BDS)/　global　positioning　system　(GPS)　is　developed　to　deliver　high-precision　time　reference　signals　for　communication　networks.　Experimental　results　demonstrate　that　the　real-time　1　pulse-per-second　(1PPS)　interval　achieved　by　the　BDS/GPS　time　link　is　better　than　0.1　ns,　with　long-term　frequency　stability　reaching　the　10-16　level.　Furthermore,　the　proposed　system　achieves　a　1PPS　signal　synchronization　precision　of　0.73　ns　in　communication　networks,　significantly　outperforming　the　other　state-of-the-art　methods.　©　2025　IEEE.