PARTNER INTERIVEW: Jason Tu, principle scientist of NFV/SDN products at ZTE (pictured), gives an update on the status of the maturity and advantages of standalone (SA) 5G, and takes a close look at pending deployments in China.

MWL: Given operators’ significant 5G investments and the current economic uncertainties, what is the motivator to allocate additional resources to enable SA?
JT: Even ignoring the steep rise in data flows caused by Covid-19 (coronavirus) quarantine measures, annual traffic growth is considerable in most countries. This means operators need to continue to invest and expand network capacity to handle the increased traffic. As the SA architecture matures, it is obvious investment in the new target architecture is a more sensible move than investment in a transition model (non-standalone)

To date, ZTE has completed thousands of SA lab and field tests with a number of global operators, including China Mobile, China Telecom, China Unicom, Orange Spain and Telefonica. These tests demonstrated the large-scale commercial capabilities of ZTE’s end-to-end 5G solution, which includes Unisite+ RAN, FLEX-E Transmission and our cloud-native 5G core.

So far, compared with other countries, China has the largest network scale and the most comprehensive application scenarios, which require a network with full specifications and high performance.

SA mode supports advanced technologies such as network slicing which can help operators develop customised offerings for vertical industries. The introduction of virtual private networks based on network slicing, for example, means operators will be able to enter the B2B market, which has a vastly larger scale than the traditional B2C segment.

We believe the commercial rollout of SA networks, including the planned launch in China by the three major operators, will prove its value and become the main choice for operators around the world.

What services will benefit the most from SA capabilities?
Ultra-reliable low-latency connections (uRLLCs), mobile edge computing (MEC) and networking slicing for vertical industries need to be based on SA mode. Network slicing, for example, as a virtual private network together with MEC are now being embraced by smart factories in China.

Why is China aggressively pushing SA buildouts at a time when most of the world is slowing down 5G deployments due to lockdown restrictions?
Actually, China’s government started the 5G deployment since 2019. With the experience of 4G network deployment and business models, Chinese operators are clearer and more confident in choosing the 5G development path. SA 5G can support larger and broader industry applications as well as the Internet of Things economy, and bring more industry transformation and value-added benefits.

Compared with NSA networks, SA 5G has advantages in being able to interconnect everything for vertical industries and support both uRLLCs and massive machine-type communications. These requirements need technologies such as network slicing and cloud-native core networks, which are only supported by the target SA mode.

Due to the continuing impact of Covid-19 in many countries, investments in 5G networks could be delayed. But we believe operators will continue to roll out 5G over the medium- to long-term. We remain cautiously optimistic about the business throughout this year.

When do you estimate Chinese operators will introduce the first commercial services running on SA networks?
Despite Covid-19, ZTE has made sufficient preparations in R&D, logistics and delivery for SA deployments for the three major mobile players. According to current SA deployment plans, progress in dozens of Chinese cities for all three, being handled by ZTE, will be ready for commercial launch before end-June. But the timing of commercial launches is up to the individual operators.

What is involved in moving to SA and what are the obstacles?
Support for handset chips using SA mode were the main obstacle before 2020. From the beginning of this year, many terminal manufacturers, including ZTE, released dual-mode NSA-SA smartphones as the supply chain for SA has fully matured.

Analysts said some regulators, including the Ministry of Industry and Information Technology in China, would halt the sale of new single-mode NSA 5G mobile phones later this year, which will encourage operators to focus on SA 5G deployments.

What capabilities is ZTE delivering to customers to streamline the process and ease the financial burden?
China’s 5G market, for example, needs not only advanced technology but also economical solutions.

ZTE’s common core adopts service-based architecture, micro-service components, stateless design and network slicing to realise flexible and agile business innovation, deployment, operation and maintenance. It meets the requirements of 2G, 3G, 4G (NSA 5G), SA 5G as well as fixed network access and full integration at the same time. ZTE’s fully integrated products will greatly reduce the cost and difficulty of evolving from 4G (NSA 5G) to SA 5G.

Supported by automation and intelligence, ZTE’s intelligent operation and maintenance solution, CloudStudio, allows one-click deployment and the rapid launch of new services for vertical industries. The introduction of AI, machine learning and root cause analysis can achieve real-time network monitoring and analysis, automatic optimisation, fault self-healing, and improve operation and maintenance efficiency.

Some analysts say sub-6GHz deployments will help set the stage for migrating to SA through the use of dynamic spectrum sharing (DSS), which enables that radio to be shared to broadcast both 4G and 5G. How important is DSS?
DSS enables the quick rollout of 5G, which has a number of key benefits.

It is a cost-effective way to introduce 5G and offers a smooth transition of legacy 4G service based on real-time co-scheduling between 4G and 5G using the same bandwidth via a software upgrade of radios without additional hardware cost.

In addition, DSS can enable ubiquitous 5G coverage as there is less penetration loss, while using sub-3GHz spectrum. There are no spectrum availability issues, while increasing the amount of 5G bandwidth improves performance.

ZTE recently worked with China Unicom to implement DSS on its network in Henan province. What were the results of that work?
Our SuperDSS is designed to make full use of spectrum with quick 5G deployment along with support for legacy voice services (circuit switch). It can support 2G, 4G and 5G bands as well as dynamic sharing of all three at the same time.

Deploying SuperDSS, the industry’s first triple radio access technology (tri-RAT) DSS solution, on China Unicom’s live network in Henan enabled the fast deployment of 5G as well simultaneous support for legacy 3G an 4G services over 20MHz of spectrum. It offers flexible and efficient scheduling capabilities, allowing 3G bandwidth to be adjusted according to service requirements, so more bandwidth can be used for LTE and New Radio (NR) sharing and improve LTE and NR user throughput accordingly.

Test results showed that when DSS is introduced with NR, LTE and UMTS, the average throughput improved about 35 per cent, while maintaining the legacy 3G voice experience and greatly improving spectrum utilisation efficiency.