5G is in an interesting stage at the moment. With 5G standalone deployments now happening at scale globally and 5G-Advanced coming, we are finally seeing the true potential of what 5G can bring. With new advanced functionalities, we can see services that extend far beyond traditional mobile broadband with the potential to transform society with unprecedented levels of connectivity and digitalization and unlock opportunities to payback CSP investments in the network.

But there is one glitch in the machine. 5G will underpin many critical use cases where network resilience is critical. This includes the ability of first responders to communicate over a 5G network slice during a natural disaster. It includes the ability for blue light services or national security to operate secure video communication with drones. From connected factories and connected mines of industry 4.0 to remote surgeries and distributed sports productions, the huge potential of 5G is primed to go live but only with failsafe network resilience.
One key component in network resilience is synchronization. Without extremely accurate, robust, and always-available timing, the network will fail to operate. Today, most mobile networks rely on GNSS (Global Navigation Satellite System), including GPS, to synchronize the networks. GNSS is an extraordinary technology since it gives a very accurate signal that can be received at no cost wherever you are in the world, as long as there is a line of sight to the sky. It comes with constraints, though, when it comes to resilience. Since the signal is weak, it is quite easily disturbed.
This can be avoided by using network-based synchronization instead. This assures youโre in control of your own synchronization without having to rely on external services. However, It does come with other challenges since traditional network-based synchronization for 5G requires hardware support in every node and doesnโt work over leased capacity. In short, we need an upgrade of what synchronization can be and the ITU is already on the case. It has begun the standardization of a network-based timing distribution protocol designed to guarantee the security and integrity of the network, which can be trusted to carry critical services.
The application in telecoms is groundbreaking, but the core technology is not new. Precision TimeNet (PTN), on which the ITU standard will be based, has been operating in mission-critical live media broadcast environments for two decades. PTN ensures the creation of a secure, highly available 5G infrastructure. This infrastructure is not only equipped to support essential societal services but is also primed to enable new and critical advanced business services, key to the monetization of 5G technology. Letโs explore the implications further.
Precise Time is a critical national service
Telecommunication networks are fundamentally about sending and receiving signals accurately. In order for the network to accurately juggle the complex transmission and reception of data from hundreds (of thousands) of devices in various locations, accurate timing and synchronization is crucial. Timing must be foundationally secure and reliable. When timing and sync is off, network performance and user experience can collapse.
If that happens when first responders are on the scene of an emergency, it spells disaster. When power grids and digital power stations require precise timing for the synchronization of electricity generation and distribution, network performance simply cannot fail. Thatโs why managing critical use cases also means that the 5G network itself must be treated as critical infrastructure. Synchronization did not present such a problem with previous generations of wireless technology. In 4G, Frequency Division Duplexing (FDD) was the primary mode for uplink and downlink communications, and RF transmission and reception were less complex. But 5G introduces new challenges.
Reliance on satellite
As mentioned, mobile networks today use either a GNSS signal from the sky to synchronize their networks or they synchronize through the networks, traditionally with network-based IEEE 1588 Precision Time Protocol, or PTP. The GNSS signal is very weak (think of it as a light bulb up in space), which means itโs very easy to jam or spoof. Disruptions can be triggered by malicious groups or by foreign powers. Recent global geopolitical events have highlighted that GNSS is nowhere near secure enough to be the single point of synchronization.
Last winter, for example, parts of Poland, Lithuania, and southern Sweden experienced significant GNSS signal disruptions, affecting aviation and navigation systems. Experts suggest that these disruptions were intentional, stemming from geopolitical tensions. Such incidents not only pose immediate operational challenges but also raise long-term national security concerns for all industries relying on satellites for critical operations. Thereโs a huge economic risk, too. A report sponsored by NIST in the US estimates the cost to the US for a GNSS failure to be over USD1 billion per day, with up to half of that tied to the telecoms sector.
Hardware dependency
Traditional PTP is a more resilient way to secure synchronization; however, it is not without complications. In order to provide the right level of sync precision for 5G, one needs to add Full Timing Support, or ITU-T G.8275.1. This requires hardware support in every node. If there is leased capacity in the network, meaning someone elseโs infrastructure is used, it will not work at all. CSP:s that lease bandwidth or network infrastructure from third-party vendors, cannot therefore use Full Timing Support over these paths.
Such hardware dependency also means that any failure in a single node could potentially impact the sync status of several other nodes downstream, posing further risk to network stability. To obviate substantial investments in hardware upgrades and avoid increased complexity in network deployment and management, another solution is needed.
A timely breakthrough
There is a proposal in front of the ITU to create an updated version of PTP. Known as Enhanced Partial Timing Support (ePTS) it is based on tried and tested technology that has been in use for over 20 years in the broadcasting industry. Accurate synchronization is crucial for digital TV (DVB-T) and since many countries recognize national TV as mission critical and have identified the vulnerabilities of GNSS/GPS, there were requirements early on for GNSS/GPS independent synchronization implementations that worked over leased capacity. The same concept can be applied to telecoms to achieve sync without relying on the GNSS signal or PTP IEEE1588 hardware support. This is where the new ITU standardization comes in, based on Net Insightโs technology Precision TimeNet (PTN).
How Precision TimeNet works
Precision TimeNet disaggregates the synchronization function from the hardware to create a sync overlay across the existing IP infrastructure. This allows all CSPs to cost-effectively transfer precise time from the central time reference sites all the way out to the radio access network. Traditionally there have been two main issues when sending accurate time over wide area networks: jitter and link asymmetries. Network jitters are typically caused by traffic interference, statistical effects, buffer handling in routers and QoS mechanisms. Asymmetries can change in any moment and is often due to protection switching or traffic reroute. These changes can be as small as 100 nanoseconds or as large as several milliseconds.
PTN solves this by streaming time stamps at a far higher rate to enable much more advanced filtering mechanisms and algorithms in combination with collaborative clock links to reduce the jitter noise and thus significantly enhance the time accuracy. With the standardization of Enhanced Partial Timing Support now in progress the ambition for the standard is to be accepted in full during the end of 2025, making the next generation of synchronization soon to become part of the mobile network ecosystem.
A vision for a new network-based synchronization
While the evolution of mobile networks has been incredible in the last years, synchronization itself has remained static. As the next phase of 5G moves into critical use cases 5G networks themselves need to be managed like critical networks. Synchronization is key for it to be resilient. Until now the industry has been content to rely on GNSS but the real and present threats to national critical infrastructure and economic security in the 5G era should give us all pause for thought. It has triggered a re-evaluation of the way we think about sync as a software separated from the hardware to become much more of a network function, securing a resilient sync for everyone, everywhere.
Net Insightโs vision is for network-based synchronization to become fully virtualized. PTN will enable the first step which is to decouple the sync function from the underlying hardware in existing network infrastructure. Eventually all synchronization nodes will themselves become virtual. Fully disaggregating synchronization from the hardware enables sync to be distributed throughout all parts of a network, reaching every node no matter how remote or complex the sites, or if a network includes leased capacity. This will be a cornerstone of network evolution with implications beyond the telecoms sector since true network-based synchronization will secure critical societal services for today, tomorrow and for decades to come.