5G is here and is changing how we communicate, work, and play. The promise of super-fast, low-latency bandwidth is transforming all industries and sectors, opening up new use cases and opportunities for innovation. However, there is a set of requirements that need to be fulfilled for 5G rollout to speed up and take place cost-efficiently nationally.
The 5G infrastructure market is growing exponentially with a CAGR of 60% and is estimated to reach a total market size of about $50 billion by 2027. 5G networks are set to handle new mission critical applications, including real-time industrial applications, autonomous cars and bluelight communication. Time synchronization is critical for 5G to function. Without precise and accurate time synchronization, the 5G services cease to work and a faulty synchronized base station will interfere with the 5G operations of other operators as well.
Telecoms operators around the world are therefore facing the pressing need to deliver accurate and secure 5G synchronization across their networks. However, so far, this requires investment which raises 5G rollout costs quite significantly. According to a report by Kearney (April 2020), the synchronization cost is estimated between 3-5% of the total 5G network rollout cost, i.e., $1.5-2.5 billion in 2027 and can in many cases require a large forklift upgrade of old infrastructure to enable PTP network synchronization - this is prohibitive for a large number of operators.
In 2022, we will be seeing an increasing number of telco companies leveraging 5G synchronization to ensure they’re ahead of the 5G rollout curve. This is the perfect time for operators to consider technology solutions that can help them achieve network synchronization quickly, securely, and cost-effectively.
Why is 5G network synchronization critical?
Network synchronization is a critical function for mobile networks, driven by the demands for higher capacity and speed for new applications and services. While the requirements for 4G/LTE network synchronization are quite demanding, the launch of 5G is bringing new and more stringent synchronization expectations for mobile networks.
With 5G comes an increased focus on TDD (Time Division Duplex) technology, which requires a much tighter synchronization, compared to, for example, FDD (Frequency Division Duplex) as in most 4G/LTE networks. Moreover, new features and advanced network techniques such Massive MIMO, Carrier Aggregation (CA), License Assisted Access (LAA), and Coordinated Multi-Point (CoMP) transmission and reception technologies require further enhancements in synchronization. The synchronization requirements cover both neighboring base stations and devices across the network.
GPS-based synchronization solutions come with compromises
There are two main methods to deliver synchronization to base stations and small cells in today’s mobile networks, Global Navigation Satellite System (GNSS) such as the Global Positioning System (GPS) and Precision Time Protocol (PTP).
GNSS solutions deploy GPS receivers together with the base station antennas. They provide highly accurate network synchronization but come with their set of limitations.
The densification of mobile networks with many small cells makes GNSS-based solutions very expensive. They are also vulnerable asit is easy to jam out GNSS signals, either by blocking them out completely ("jamming") or by replacing the GNSS signal with a similar but incorrect signal ("spoofing"). Several countries, such as Sweden, have therefore mandated 5G operators to ensure GNSS-independent synchronization to receive a 5G license, since 5G is considered mission-critical infrastructure.
5G mobile networks also bring increased demands on cell density, indoor cell coverage, and deployment in challenging geographical areas, such as tunnels, buildings, and factories where satellite visibility is compromised. Likewise, deployment in areas with limited satellite visibility, such as urban areas where buildings obstruct the view and rural areas with deep forests and canyons, demonstrates the limitations of GPS-dependent solutions.
PTP solutions are cost-prohibitive
An alternative method is network-based timing based on packet switching technology, mainly Precision Time Protocol (PTP or IEEE1588v2), supported by Synchronous Ethernet (SyncE). While PTP solutions do not suffer from the weaknesses of GNSS-based timing in terms of safety, robustness, and ease of deployments, there are still considerable challenges when introducing support for PTP and/or SyncE in mobile networks. In particular, the transition to network-based timing requires considerable investments in new or upgraded hardware equipment and software since PTP require every node to provide on-path PTP support (in HW) to ensure the accuracy. High-precision synchronization may require existing networks to be reorganized to provide proper conditions for the communication of timing information. Alternatively, new, parallel infrastructures may need to be established exclusively to carry this information. Consequently, for many operators it will be a huge undertaking for them to transition their full networks to network-based timing.
In addition to the main approaches described above, there are other synchronization technologies that could be considered for 5G mobile networks. One is White Rabbit, which combines PTP and SyncE and introduces additional mechanisms to improve synchronization accuracy. It is specifically designed to meet the stringent requirements for particle accelerators and is typically used in dedicated fiber or LAN environments. Another approach is Over-the-Air Time synchronization (OTA), which is designed for ultra-reliable and low-latency communications (URLLC). OTA is a radio interface-based synchronization solution that has been used for synchronizing base stations in 4G/LTE and is an alternative that is put forward for 5G mobile networks in the RAN (Radio access Network).
An innovative approach to 5G synchronization
Time synchronization is increasingly important for other market segments, including power networks, synchronization of distributed databases, stock exchange trading, distributed video production, and defense networks. The synchronization challenge is highly relevant for other real-time critical network installations, such as digital terrestrial television (DTT) networks with stringent frequency, phase synchronization, and accuracy of ~1 µs requirements.
To address this challenge, the / has been developed and deployed in DTT networks in 15 countries and was recently chosen by Turk Telekom for their 5G rollout. Precision TimeNet provides distribution of absolute time with very high accuracy over the existing IP network. Since it does not require all nodes to be upgraded for on-path PTP support, the network-based synchronization solution may significantly reduce CAPEX and OPEX, as well as, rollout times. It creates a virtual synch network over the existing IP network that distributes time from clock sources such as atomic clocks out to base stations or the radio access network while managing all redundancy, security, and asymmetries in the IP network. The Precision TimeNet solution has been augmented with software for running over public managed IP networks with possible delay asymmetries. It is open and interoperable, enabling operators to integrate it within their existing network infrastructure. Importantly, it complements GPS-based solutions, addressing their security challenges.
The solution enables geographically disadvantaged regions such as rural areas to access good bandwidth and contribute to closing up the digital divide by removing the cost of replacing the entire underlying network infrastructure to enable 5G deployment. PTN is also an environmentally sustainable solution as it reuses existing communication equipment, minimizing the telecom network footprint.
The future of telecom innovation
5G brings the future of telecom and mobile communication today, powering new use cases and business models across industries. However, 5G synchronization has been a key hurdle in the acceleration of 5G rollout as, so far, the telco industry had to sustain high additional costs.
Precision TimeNet is an innovative solution that leverages existing telecom networks without requiring further CAPEX. In doing so, it delivers the accuracy, security, and low latency operators need to deploy 5G. It also enables the interoperability they need to integrate it within their current infrastructure. This levels the playing field for telco operators across the world that can welcome the future and bring the 5G revolution to countries and regions faster and more efficiently.
