A brief discussion on six key technologies to reduce 100G system power consumption

　　1. Energy consumption is the core issue of 100G large-scale commercial use

　　According to statistics from the International Energy Agency (IEA) in 2008, from 1973 to 2006, global energy consumption increased by 73%, and C02 emissions increased by 79%. Energy consumption has led to the greenhouse effect and a series of natural disasters. For the sustainable development of enterprises, mainstream operators and equipment manufacturers have successively launched energy-saving and emission-reduction plans to meet the challenges of energy consumption.

　　100G is in full swing and has commercial conditions. However, 100G still needs to solve some challenges to achieve large-scale deployment. This is mainly because the implementation mechanism of 100G technology is complex, the optical receiver needs to use coherent reception and DSP processing, and the key chips are not ASIC-based, resulting in high power consumption of the entire 100G system. As can be seen from the figure below, when the power consumption of a 100G single board reaches about 280W, it can achieve the same energy efficiency ratio as 10G. Therefore, how to reduce the power consumption of 100G systems and provide green and low-carbon solutions has become a hot topic of concern for major communication equipment manufacturers.

　　Figure 1 10G, 40G, and 100G power consumption comparison

　　2. Six key technologies for 100G OTN green energy saving

　　The 100G system mainly consists of four parts: 100G service board, OTN cross unit, fan board, and management module. The power consumption of the 100G service board accounts for about 70% of the total system power consumption. The functional modules of the 100G service board can be divided into three parts: client-side optical module, service mapping processing unit, and line-side optical module. Among them, the service processing chip in each functional module accounts for about 60% of the power consumption of the 100G service board.

　　Figure 2 Power consumption distribution of equipment and service boards

　　The following article will discuss ASIC, optical modules, power supplies, etc., and introduce the current mainstream solutions for reducing 100G system power consumption.

　　Key Technology 1: Continuously Improving ASIC Process

　　At present, mainstream wavelength division equipment vendors in the industry have independently developed ASIC chips and reduced chip power consumption by improving chip manufacturing processes, laying the foundation for reducing power consumption in OTN systems. The design of 100G systems has also been keeping up with the pace of chip process improvements and enjoying the huge energy-saving benefits brought by upgrades. By improving the ASIC process, the energy-saving results of 100G service boards are significant.

　　From the data in the figure below, we can see that the 45nm process is now mature and can reduce gate circuit power consumption by 50% compared to the 130nm process. When ASIC design reaches 28nm in the future, the power consumption of 100G systems will drop significantly, reaching or even exceeding the current 10G unit bit power consumption level.

　　Figure 3 Energy saving effect of ASIC process improvement

　　Key technology 2: Reducing optical module power consumption

　　In 100G systems, the power consumption of optical modules accounts for a considerable proportion, so reducing the power consumption of optical modules is also of great significance.

　　The optical module mainly adopts adaptive power management technology to dynamically adjust the working state of the module's key power consumption chips, which can effectively reduce the power consumption of the module in standby state by up to 60%.

　　Figure 4 Optical module power management optimization

　　Key technology 3: Improving power conversion efficiency

　　The improvement in power efficiency has played a significant role in reducing the power consumption of the entire device. Because all boards use power modules, even a 4% increase in efficiency can save astonishing energy.

　　In order to improve the power efficiency of 100G wavelength conversion boards and line cards, the power conversion efficiency can be increased to 88-89% by using high-efficiency switching power supplies. At the same time, by using active and standby 48V power MOS tubes, reducing the types of power supplies, and optimizing the power architecture, the power efficiency can be increased to 90%.

　　Key Technology 4: Dynamic Power Management Technology

　　At present, the vast majority of 100G devices support dynamic control of power consumption to achieve refined management, mainly including port control technology, intelligent fan technology, dynamic power control, etc.

　　Port control technology: When the port is idle, it supports automatic shutdown, which can significantly reduce the energy consumption of the OTN system.

　　Intelligent fan technology: With intelligent fan technology, the fan can run at 50% speed when the equipment is working at normal temperature, which can save 70% of the fan power consumption;

　　Dynamic power control: When the board is not working, it supports setting the board to standby mode, saving 40% energy; when the 100G system detects that the optical module is not in use, it shuts down the chip on the processing path corresponding to the channel, reducing power consumption by more than 10%.

　　Based on the above intelligent power consumption monitoring and management technology, the 100G system can achieve a 10~20% reduction in power consumption.

　　Figure 5 Dynamic management reduces power consumption

　　Key Technology 5: Large-capacity OTN cross-connect improves 100G equipment energy efficiency

　　First, 100G technology combined with a large-capacity OTN cross-matrix can achieve 100% utilization of 100G bandwidth when carrying small-granular services. Compared with the traditional board-level wavelength conversion board solution, it greatly improves the utilization of line bandwidth and improves energy efficiency by more than 30% compared to traditional equipment.

　　Figure 6: Achieving 100% utilization of 100G bandwidth based on the OTN platform

　　Secondly, most of the current mainstream OTN equipment uses intelligent warm backup technology for cross-connect units. While ensuring network and equipment performance, the power consumption of the cross-connect units used for backup is reduced by more than 60%, so the power consumption of the 100G OTN system is further reduced.

　　Key technology 6: Combine ASON technology to reduce network energy consumption per unit bandwidth

　　The introduction of ASON features in 100G OTN networks can also improve the utilization efficiency of optical line bandwidth. Take the simplest comparison of 1+1 protection and ASON protection under three nodes as an example, as shown in the figure below. Assuming that the service bandwidth between AB is 100G and the service bandwidth between BC is 100G, considering 1+1 SNCP protection, the required capacity of AB, BC, and CA links on the ring network is 200G; if 100G ASON protection is considered, the required capacity of AC link is only 100G, which saves 16.67% of the total network bandwidth, so the network energy consumption is also reduced by 16.67%.

　　Figure 7 Comparison between 1+1 protection and ASON protection for three nodes

　　3. Huawei effectively solves 100G energy consumption issues

　　At present, mainstream equipment manufacturers such as Huawei have adopted the above combination of technologies to systematically optimize the energy saving of 100G products, effectively reducing the power consumption of 100G systems and improving the energy efficiency of networks. At present, the energy efficiency ratio of Huawei's 100G system (based on 10G) is close to 0.8, which strongly supports the commercial deployment of global customers. So far, Huawei has helped more than 50 operators around the world to deploy 100G networks.

　　In the future, with the improvement of chip technology, the popularization of smaller package optical modules, and the application of higher integration systems, the energy efficiency ratio of 100G will continue to be optimized. Green energy saving is a major mission for the development of the industry. Huawei will continue to provide the best green energy saving solutions, promote the continuous development of the industry, help global customers, and jointly build a future optical network of green communications.