The Second Phase of 5G: NTP Time Servers Hold the "Pulse" of Networks

Who controls the "pulse" of networks in the second phase of 5G? On the surface, telecom operators build and operate networks, while equipment vendors supply base stations and core network hardware. Dig deeper, however, the core question is how to keep this massive network operating in perfect sync so that 5G and 5G-A can truly empower thousands of industries.

1. Denser Base Station Deployment: How to Achieve Uniform Timing Alignment?

TDD (Time Division Duplex) is the mainstream working mode for current communications. Simply put, all base stations on the same frequency band must transmit and receive signals in alternating time slots. If timing misalignment occurs between two base stations—one transmitting while the other receives—signal collision will happen. Minor collisions lead to reduced network speeds and higher latency; severe ones cause frequent disconnections and terminal dropouts, drastically impairing user experience and commercial network reliability. Accordingly, communication standards mandate a timing synchronization accuracy of ±1.5 microseconds between base stations.

This only represents the baseline communications requirement. Unlocking the full potential of 5G relies on coordinated technologies including MIMO, CoMP (Coordinated Multi-Point), CA (Carrier Aggregation), and multi-carrier convergence for 5G-A—core technologies that boost throughput and expand coverage. These demand far higher timing precision, raising the synchronization accuracy threshold to ±130 nanoseconds.

As vertical industry use cases of 5G roll out at scale, emerging applications such as autonomous driving, unmanned logistics, and intelligent robots impose even stricter timing precision requirements on networks. Connected vehicles and smart manufacturing require synchronization accuracy at the 10-nanosecond level, while centimeter-level high-precision positioning services call for an ultra-stringent standard of ±3 nanoseconds.

Crucially, evolving networks will only raise timing accuracy requirements further. Against this backdrop, synchronizing millions of base stations to operate in lockstep has become the linchpin for 5G to deliver tangible value to all industries in its second development phase.

2. Space-Ground Redundancy: Saisi High-Precision Synchronization Networking Architecture for 5G

To address the synchronization challenge of millions of base stations, the three major domestic telecom operators have widely adopted a space-ground redundant synchronization architecture combining GNSS satellite timing and 1588v2 terrestrial timing in recent years. This architecture transmits timing signals over terrestrial bearer networks as a complement to standalone satellite timing, greatly enhancing overall network reliability.

As a core supplier specializing in 5G clock network solutions, Saisi accurately caters to timing upgrade demands of communication networks and has developed a nanosecond-level high-precision synchronization networking architecture fully compatible with operator nationwide network deployments.

Frequency Synchronization Layer

Built on operators’ existing network infrastructure, Saisi deploys its self-developed SM2000 integrated time-frequency devices (with precision better than ±5 ns) across national primary reference clock (PRC) nodes, provincial primary-backup Local Primary Reference (LPR) nodes, and local access nodes. The equipment delivers a stable nationwide frequency benchmark to unify baseline network timing.

Time Synchronization Layer

Deployed on a prefecture-level city basis, each local network is equipped with one primary and one backup Saisi high-precision time server. The servers acquire standard time signals via satellites and distribute timing data to all 5G base stations through terrestrial bearer networks, forming a dual space-ground backup system with satellite as primary and terrestrial as backup. This fully meets ultra-high precision timing demands for high-end scenarios including computing power networks and industrial internet.

The SM2000 integrated time-frequency device deployed across the entire solution integrates complete frequency synchronization and high-precision time synchronization capabilities in a single unit. It offers backward compatibility with legacy SDH networking, supports standard G.811/G.812 E1 and 2048 kHz frequency outputs, and adapts to all mainstream 5G transmission links including IP/OTN/DWDM, microwave, and EPON. It can serve as backbone PRC/PRTC reference clocks, or as secondary relay clocks deployed at prefecture and county levels to distribute nanosecond-level timing to massive CU/DU/AAU base station units.

3. Steady Shipment to Continuously Empower High-Quality Development of the Second 5G Phase

Having successively won equipment supply bids for clock synchronization network projects from the three major telecom operators, Saisi SM2000 integrated time-frequency devices maintain consistent, stable shipments. Validated by network access testing and long-term commercial operation, the products sustain high-quality progress for the second phase of 5G development.

As 5G and 5G-A networks continue to evolve, industrial requirements for timing synchronization precision will keep rising. To meet the ever-increasing accuracy demands of upgrading communication networks, Saisi stays at the cutting edge of time-frequency synchronization technology, iteratively upgrading high-end synchronization hardware and networking solutions.

Moving forward, Saisi will deepen its focus on time-frequency synchronization. Through technological innovation, stable product supply and premium technical services, we will continue to support operators in building next-generation communication networks with high precision and ultra-high reliability, facilitating high-quality development in the second phase of 5G and forward-looking R&D layout for 6G technologies.