How Huawei’s unique insights into network evolution enable the optimisation of energy efficiency

Dr Fang joined Huawei in 1999 initially as an R&D Engineer of GSM products before in 2003 moving to work in sub-Saharan Africa (SSA) as marketing manager for six years, during which time Huawei’s market share in SSA climbed from 5% to 30%. When Dr Fang returned to China in 2009, he took over as Vice President for Huawei’s Network Energy department, drawing upon his familiarity with the challenges of providing power to cell sites in SSA to achieve Huawei’s vision of being the “ICT Energy Efficiency Management Specialist”, dedicated to provide high reliability, high efficiency, and low carbon emission solutions for telecom operators and towercos.

TowerXchange: How do you foresee telecoms networks in Africa evolving, and what are the implications for energy efficiency programmes?

According to Huawei’s statistics, the total number of sites in Africa has now reached 180,000. We think the main GSM and UMTS operators will add more sites to extend voice coverage for more subscribers, but also add more small cell sites to infill capacity in high end markets for data services – we anticipate 100,000 new sites will be required in the next several years.

Last year, most African operator’s ECR (Energy Costs as a proportion of Revenue) was over 6%. In comparison, ECR averages just 2-3% for operators outside of Africa. So African operators face a big challenge and pressure from energy costs, while there is also a greater opportunity to save energy costs for African operators compared with anywhere else in the world.

Huawei has just launched the New Generation Telecom Power Solution, MTS (Migrate Towards Simplicity) at the 2014 Intelec exhibition in Canada. The MTS, with innovative site-level high efficiency features, will no longer stay at the stage of improving the efficiency of a single module, but increasingly improve the efficiency of the entire system, the entire site and the entire network. The MTS will not only improve energy efficiency but also simplify the power system. For example, the MIMO (Multi Energy Input, Multi Mode Output) makes energy available at anytime and anywhere, which indicates the input mode of grid, solar, DG, battery and output mode of 220V AC, 48V DC, HVDC, and 24V DC.

TowerXchange: To what extent is the drive toward energy efficiency in cell site design caused not just by rising energy opex, but also caused by growing data demand driving the energy load on some sites to and beyond capacity?

For power systems, reliability is the top priority. How to improve reliability is an important factor we consider at first in product design. We have dual source designs and an OSS (operation support system) to insure reliability.

For dual source design, there are at least two power sources for each power system. Usually, the battery is the basic backup for the power system and either DG or solar is an optional choice .

In addition, the OSS can gather the real time running status of the site. Once there’s any abnormal issues happening, an alarm will be sent out automatically so that the problem can be fixed in time.

According to our statistics the load for sites in SSA is normally at around 30-40%, but if the site is a shared site it will become more of a challenge.

However, this will not be a problem since our rectifier has a modular design, supporting smooth expansion in the future. Huawei can provide capacity-related suggestions for future energy requirements since Huawei has abundant experience in the field of telecom energy.

TowerXchange: How do the philosophies of network energy planning need to evolve in an era of infrastructure sharing? How can power systems be designed to maximise efficiency as the load increases as more tenants are co-located?

Thanks to Huawei’s focus on telecom equipment solutions for our customers, we are uniquely positioned to forecast service development, so we are able to provide informed suggestions for the evolution of network energy systems to meet the requirements of future services – Huawei know how much power should be provided to meet growing customer needs. This is one of Huawei’s key differentiators from pure energy equipment providers.

Huawei is committed to the ‘era of infrastructure sharing’. For example, sometimes our customers want Huawei propose an appropriate location to build a new site. Where possible, we will always suggest sharing existing sites to minimise capex.

TowerXchange: For our less technical readers, please explain the role rectifiers play in cell site efficiency, and therefore the importance of the efficiency of Huawei’s rectifiers.

The rectifier’s function is to change the current from Alternating Current (AC) to Direct Current (DC) as most telecom equipment needs DC not AC. Higher efficiency rectifiers, such as Huawei’s market leading solutions, reduce energy consumption and heat dissipation, which in turn reduces air conditioning runtime, even removing the need for air conditioning altogether.

Huawei manufactures the world’s most efficient rectifier, which can now achieve a peak conversion efficiency of 98%, which is a significant improvement upon the previous 94% conversion efficiency. At 98% conversion efficiency, Huawei’s rectifier can reduce conversion power loss by 66% more than a mainstream rectifier with 94% conversion efficiency. Our rectifier also improves power density and reduces power failure rates and noise levels. Critical for towercos, the rectifier also saves 50% user space in comparison with traditional rectifier module.

TowerXchange: You mentioned the potential for reducing or eliminating the need for air conditioning. Are the next generation of cell sites going to be designed primarily with outdoor equipment, thus negating the need for the parasitic load of air conditioning? How can existing sites’ air condition be made more efficient in the meantime?

First, outdoor is a trend. Most new build sites will use outdoor equipment, but for existing sites we have several ways to reduce air conditioning runtime.

Most of the telecom equipment, such as the BTS, transmission box et cetera, can work normally at 55°C. But the battery is quite sensitive to temperature. This suggests two solutions: first, we can divide the cabinet into two compartments, one for telecom equipment in which we use heat exchange, the other compartment just for batteries, where we use more efficient air conditioning just for the batteries. The second solution is to apply high temperature batteries which can even work at 45°C, reducing or eliminating the need for air conditioning runtime and associated parasitic load. The battery’s cycle life can be up to 1,200 cycles @60%DOD at 45°C.

TowerXchange: Where should the ‘intelligence’ be gathered from a cell site, from third party RMS sensors, or from sensors integrated into equipment? And how can the data gathered from cell sites be translated into actionable intelligence?

Huawei OSS NetEco focuses on the unified management of site energy, environment, and security components.

By monitoring the performance and alarm information of related devices in real time, NetEco enables maintenance personnel to remotely manage sites. Maintenance personnel can access the NetEco through a web browser or mobile app. Besides, our OSS can also provide a standard interface with third party sensors and equipment.

By collecting and analysing statistics on site power consumption, NetEco provides data support for energy conservation suggestions. NetEco provides refined management of electricity, fuel consumption, assets, and maintenance services. It supports intelligent analysis and statistics collection, and provides asset inventory management and maintenance notification functions.

Furthermore, if the telecom equipment and energy solution are provided by Huawei, then both of them can share the transmission device, which will help customers to save more opex.

TowerXchange: Are Huawei providing energy solutions to any emerging market towercos? If so, how do their monitoring requirements differ from those of MNOs?

Huawei are already providing energy solutions to several towercos in Africa and Myanmar.

Our solution can monitor and manage the power consumption for each tower tenant, so towercos can support and measure the energy consumption of several operators, and build their business models for power services accordingly.

TowerXchange: What can Huawei offer that other network energy equipment and service providers cannot?

Huawei provide solutions for the evaluation and reduction of energy consumption across the whole network. Because Huawei is the market leading provider of telecom equipment, we know how network technologies are evolving in the future, so we know how to improve the efficiency of power generation from remote cell sites to heavy traffic sites in dense metropolitan areas. For example, we can build in intelligent redundancy, so that when traffic reduces in the evening, we can shut down some rectifier modules to reduce power consumption.

Huawei is the leading ICT supplier with a commitment to the green agenda. Huawei provides a complete set of green power solutions, from efficient DG to solar and battery hybrids, controllers, rectifiers and energy OSS. We provide network energy solutions not only to help our customers reduce energy opex, but also to support their corporate social responsibility objectives, such as reducing CO2 emissions.