China Mobile Guangdong: Building All-optical City Clusters for Green Development

The global economy has experienced both rapid development and increasing environmental problems. Developing a green economy and realizing green growth are key to sustainable development and a low-carbon future that reduces energy consumption and emissions.

In 2007, China Mobile implemented its Green Action Plan and has since saved nearly 10 billion kWh in electricity and reduced CO₂ emissions by 6.3 million tons. By integrating IT solutions in various industries, it has helped other companies reduce emissions by more than 800 million tons.

To meet new challenges, China Mobile upgraded the Green Action Plan to the C² Three Energy Plan in July 2021. C² represents carbon peak and carbon neutrality and underpins the new green development model of "3 Energies and 6 Greens".

"3 Energies" refer to three major areas of action: energy-saving, clean energy, and empowerment. "6 Greens" refer to six paths that enable our goals: networks, energy use, supply chain, office, empowerment, and culture. 

Based on this plan, China Mobile formulated its 14th Five-Year Plan targets. The company aims to increase its total telecoms business volume by 160% while reducing total energy consumption and the carbon emissions of its telecom services per kWh by at least 20%. The company is also looking to quadruple its energy conservation outcomes to above 40 billion kWh and thus surpass its 13th Five-Year Plan. China Mobile intends to reduce its carbon emissions by up to 56 million tons by 2025 and help industries double emission reductions to over 1.6 billion tons.

For the 3 Energies, China Mobile Guangdong is phasing out energy-intensive, inefficient, and outdated equipment, and is committed to building efficient, green network architecture and using high-quality, all-optical networks to underpin the green digital economy and help industries save energy and reduce emissions.

Phasing out energy-intensive, inefficient, and outdated equipment

China Mobile has been upgrading its telecommunications equipment to improve the energy efficiency of its networks, enhance green operations, and promote the  green and sustainable development of the telecommunications industry.

With the phasing out of old PSTN telephone systems and the reconstruction of 2G and 4G base stations with IP technology, traditional SDH and WDM optical transmission networks cannot cater for the rapid growth and diversification of data services. SDH equipment has a low level of integration, occupies a lot of space, and consumes much energy per bit, making it a focus of China Mobile's energy, emissions, and equipment retirement strategy.

In October 2019, China Mobile Guangdong held a conference on retiring SDH equipment. In line with the resulting plan, light-loaded SDH NEs and SDH equipment carrying wireless 2G services or group customer services were integrated and migrated to the next-generation bearer network and all services transferred from the SDN network.

At just one site where Guangdong Mobile Huizhou used GSM equipment, 55 sets of old SDH equipment and 308 DDFs had occupied 152 cabinets – each cabinet was 0.6 m long, 0.6 m wide, and 2.2 m high, and total power consumption exceeded 20,000 W. The next-generation OTN equipment used to replace the old SDH equipment offers features like hard isolation, security, and low latency, but it’s also congestion-free and saves a lot of space and power thanks to new components and processes. Moreover, 106 fewer cabinets are required, saving 7,000W in electricity and reducing electricity fees by about 64%. In addition to GSM equipment, around 3,500 sets of SDH equipment at other sites are gradually being powered off and retired. The space and power saved can be used to deploy IDCs, cloud computing, and edge cloud over the next few years to better support new services like enterprise leased lines, DC interconnection, and small and micro enterprise services.

Guangdong Mobile Shaoguan also faced a similar problem: 80% of its 1,500 sets of SDH equipment had been running for over 10 years, taking up a lot of space and consuming high amounts of electricity and fiber core resources. An increasing number were also nearing warranty end, presenting great security risks to services. The branch proposed the bold idea of retiring all SDH backbone/aggregation equipment on the entire network.

During the 7-month project, Guangdong Mobile Shaoguan retired 924 pieces of equipment, saving about 1.47 million kWh of electricity and more than 1 million yuan (US$158,890) in annual electricity fees. A total of 130 racks were removed, freeing up 400 square meters of space and 11,600 fiber cores per kilometer. The upgraded network uses less energy and offers personalized functions, including fast service provisioning, on-demand bandwidth adjustment, efficient self-service operations, and on-demand elastic billing.

To date, about 5,000 sets of old SDH equipment have been removed from the network in Huizhou and Shaoguan, freeing up 3,000 square meters of space, saving 7.9 million kWh of electricity per year, and reducing CO₂ emissions by more than 5,000 tons – the equivalent of planting 196,000 trees.

In the future, China Mobile Guangdong will continue retiring energy-intensive, inefficient, and outdated equipment to provide a better green development ecosystem for the Greater Bay Area.

Establishing the world's largest green switching hub

The emergence of content such as short videos, ultra-high definition videos, live streaming, online education, VR/AR, and cloud gaming has caused China Mobile Guangdong's service traffic to increase significantly, with an average annual growth of 49%. By the end of 2022, the company's network capacity will need to double, with a node's maximum capacity reaching 268 Tbit/s. However, if China Mobile Guangdong had continued to construct networks in its usual way, huge challenges would arise at most sites with equipment room space, support power systems, and air conditioners.

In 2019, China Mobile Guangdong proposed an efficient, intensive, and cost-effective reconstruction model based on OXC equipment. OXC equipment supports Pbit-level, cross-connect capacity, and scheduling capability that’s 10 times higher than that provided by ROADM equipment. In fact, one piece of OXC equipment is equivalent to nine pieces of traditional ROADM equipment.

OXC equipment supports up to 32 dimensions of optical cross-connection scheduling, making it possible to achieve 3D, mesh-based interconnection between 21 cities. It also features simplified architecture, efficient scheduling, ultra-low latency, and flexible connections, while reducing energy consumption across the entire transport network.

China Mobile Guangdong has undertaken many successful reconstruction cases, including the network reconstruction of China-Singapore Guangzhou Knowledge City. It’s equipment room for this case features 16 optical directions, which would normally require eight racks and many complex external fiber patch cords within and between these racks. However, next-gen OXC equipment has replaced complex external fiber connections with an all-optical backplane. Integrated into one rack, this backplane saves 87% in space and reduces power consumption by 40%.

China Mobile Guangdong has deployed 110 sets of OXC switches in the Greater Bay Area, making it the world's largest green OXC switching hub. With a traditional solution, a site requires five to eight cabinets compared with just one for the OXC solution, reducing equipment room space requirements by an average of 70% and power consumption by 30%. The hub saves about 2.3 million kWh of electricity and reduces CO₂ emissions by more than 1,400 tons every year, equivalent to planting 49,000 trees.

A green all-optical city cluster for a green digital bay area

China Mobile Guangdong serves more than 100 million mobile users, 16 million home users, and 1.8 million enterprise users. Optical networks are essential to maintaining growth with large-scale services while ensuring a high-quality customer service experience.

5G and gigabit optical networks are key parts of new infrastructure and crucial for the development of the digital economy. China Mobile Guangdong has formulated a strategy for the Greater Bay Area of building all-optical network infrastructure to facilitate future home networks, IoT, and smart cities.

Optical fiber has clear advantages over copper lines in terms of bandwidth, latency, anti-interference, and reliability, while also consuming 60% to 75% less power. As the greenest communications medium, the industry is honoring its low carbon commitment through the extensive deployment of optical fiber networks worldwide.

China Mobile Guangdong has deployed more than 1 million kilometers of optical cable, covering 21 cities and 130,000 villages in Guangdong, creating all-optical city clusters in the Guangdong-Hong Kong-Macao Greater Bay Area.

Building all-optical city clusters is a systematic project comprising all-optical base, all-optical network brain, and all-optical services.

All-optical base serves as the foundation of service innovation. It plays a similar role to subways or high-speed railways, featuring simplified architecture and large capacity, while saving energy. China Mobile Guangdong has deployed more than 2,000 OTN optical nodes, including 110 sets of all-optical OXC switches, creating a 1-2-3 ms latency circle within the Greater Bay Area. “1-2-3 ms” refers to 1 ms latency within a city, 2 ms latency between cities, and 3 ms latency anywhere within the Greater Bay Area. All-optical scheduling allows one-hop direct transmission, greatly reducing the required number of relay devices, transition devices, and electrical signal switching and processing devices, realizing optimal power consumption for information transmission.

The all-optical network brain functions as the dispatch center of subways and high-speed railways. With SDN and AI, it implements intelligent management, control, and analysis on all-optical networks, providing resource visualization, automatic service provisioning, and precise troubleshooting for all-optical services. This has greatly improved operation and energy efficiency, greatly reducing emissions.

All-optical services are a range of services based on the all-optical base, including OTV 4K/8K ultra-high definition live streaming, premium OTN private networks, premium VR home broadband, and P2MP optical building. The premium OTN private network has supported the digitalization of a range of industries, including security, banking, government, and healthcare. The OTN P2MP optical building solution for commercial buildings improves the speed and quality of private lines for SMEs, providing them with premium networking and cloud-access private lines.

In Guangdong, medical care is now accessible from anywhere, financial transactions are completed within seconds, and AI is accelerating industrial transformation.

China Mobile Guangdong is using IT to save energy and reduce emissions improve resource utilization, reduce production costs, and promote the high-quality  development of the green digital economy through green all-optical networks.