Embracing a New Era of Wireless Communications with Technological Innovation

An interview with Pu Yingchun, chief engineer of ZTE's GSM/UMTS products

The mobile communications industry is experiencing great changes in 2010. Mobile Internet and smart terminals are developing rapidly, and with such fast-paced development, network owners are put under pressure to quickly evolve their networks to meet high performance and data rate requirements. As tariff-per-bit continues to decline due to fierce market competition, more attention is being focused on network construction and operation costs. ZTE is committed to continuous innovation in the wireless sector. Its wireless products have made inroads into high-end European and North American markets, and the company now ranks among the world’s leading wireless suppliers. To gain greater insight into ZTE’s wireless innovation, Journalist Fang Li recently interviewed Pu Yingchun, Chief Engineer of ZTE’s GSM/UMTS products.

Journalist: With the rapid growth of mobile Internet and popularity of smart terminals, mobile broadband networks have become an inevitable trend. What challenges do you think traditional mobile operators face?  

Pu Yingchun: It is inevitable that mobile operators will develop mobile broadband data technology. However, they must address issues of multinetwork convergence and reduce CAPEX and OPEX.  

In the development of mobile communications, some well-known equipment suppliers have lagged behind, some have withdrawn from the industry, and some have merged with other companies. Sustained development of vendor business has therefore been a major concern of operators. It is crucial for operators to choose a reliable, stable, and consistent long-term partner.

Traditional base stations and networking modes do not support smooth upgrade and evolution, and this results in high-risk investment and long business cycles. To satisfy development trends in mobile communications, a solution needs to be found that allows for flexible configuration of different systems and standards. Software Defined Radio (SDR) is an ideal choice. Since it was introduced, SDR has proven to be a great strength, and in only two or three years, has become widely accepted throughout the industry. It is an effective solution to knotty problems faced by operators in network construction.

J: ZTE has insisted on creating customer value through technological innovation. Could you talk about how ZTE innovates to help operators cope with new challenges?

Pu: ZTE took the lead in introducing SDR to wireless communications. We set the trend of deep network convergence by inventing the SDR platform. Mobile networks such as GSM, UMTS, LTE, CDMA, and WiMAX can be completely converged on a unified, advanced hardware platform through software configuration.

In 2008, ZTE launched the industry’s first SDR next-generation base stations as well as an innovative all-IP Uni-RAN solution featuring multimode and multiband convergence, smooth evolution, and energy conservation. SDR and Uni-RAN represent a revolution in wireless network construction. They simplify network structure, make multinetwork convergence possible, and allow smooth evolution toward LTE―the next-generation high-speed wireless access technology.

Our ultimate goal is not necessarily technological innovation, but to create real value for customers. A distinct advantage of our SDR base stations is multimode and multiband convergence. This is a great benefit to operators running both 2G and 3G networks. They need only one set of infrastructure equipment instead of two, so their investments in equipment, space, and auxiliary facilities are significantly reduced.

CSL―Hong Kong’s leading mobile operator―originally ran two networks of dual modes on three frequency bands. This resulted in complicated network architecture, large investment in hardware upgrade, and high maintenance costs. By adopting our Uni-RAN solution, CSL has greatly reduced its network TCO. The original 2G and 3G networks have been converged into one; the number of base station racks has been reduced from 5,019 to 1,500; and unified network management and maintenance has been implemented. New SDR base stations with all-IP architecture support FE/GE interfaces, and allow transmission facilities to be shared between different networks. After the transmission change from original E1 to FE, CSL can reduce expenses by 86 million HKD annually.

Another technological innovation featured in our SDR base stations is a high-efficiency power amplifier. Using a unique digital power algorithm and dynamic power tracking (D-PT) technology, power amplification efficiency can reach 50%, and average power consumption decreases by 45%. This reduces energy consumption and lowers operational expenditure.

SDR base stations also support distributed architecture. Because BBUs and RRUs are small and lightweight, they can fit into existing space, or may even require zero-footprint installation. During installation, no special tools are required for transportation. In our Montenegro project, 70% of base station sites were located in mountainous areas, 40% of which were snow covered.  Poor traffic and infrastructure facilities there presented a great challenge to our engineers.  Despite these difficulties, our project team completed configuration and swapover of 237 2G/3G base stations within 53 days. We fulfilled the requirements of our customer and won high recognition from them. The success of this project can be attributed to the hard work of our project team and also the great value SDR base stations brought to our customer.

Our SDR base stations and Uni-RAN solution have been widely adopted by European operators such as Telenor Montenegro, Telenor Hungary, E-Plus Group Germany, KPN Belgium, Sonaecom Portugal, and Cosmote Romania. Their 2G and 3G networks are now converged, and allow for smooth evolution to HSPA+ and LTE through software upgrade. Next-generation SDR base stations have become the preferred choice for mobile operators worldwide.

J: Many operators have special requirements. What attempts has ZTE made in the area of customized service? In this era of cut-throat competition, how does ZTE satisfy market demands for customization?

Pu: Operators need to provide differentiated service in order to compete. Therefore, they need innovative technologies and solutions to help maintain a competitive edge or to elevate their brand image. ZTE is a latecomer to the mobile communication industry, which makes it all the more important to provide value through innovative and differentiated products and services. This will elevate ZTE’s status within the industry. ZTE’s many success stories are testament to its strong emphasis on customized service.

In Hong Kong, we took the lead in commercializing SDR base stations, and converged GSM, UMTS, and LTE. We also provided a customized HSPA+ and UMTS 900M solution for CSL, with a peak data rate of 18Mbps. In July 2010, e-Zone—a reputable electronic journal in Hong Kong—tested voice quality and data rates of four local UMTS operators: SmarTone-Vodafone, CSL, H3G, and PCCW. The results showed that CSL’s network performed well in providing smooth, stable video programs with quick response.

CSL and ZTE also announced in July 2010 a strategic move to deploy the world’s first commercial 1800/2600MHz dual-band LTE network, and to upgrade the 3G network data rate to 42Mbps using dual-carrier technology. The launch of LTE and dual-carrier HSPA is another initiative following the launch of HSPA+ 64QAM. This new technology gives CSL a technological advantage, strengthens the position of its mobile data services in the market, and improves mobile user experience. CSL’s brand image has been elevated to a new high.

ZTE not only strives to make technological breakthroughs and to satisfy customer requirements, but also incorporates customized service into engineering and project implementation. Despite difficulties in the CSL project, including complex wireless environments, difficulty in site acquisition, and a long review and approval wait for an engineering license, ZTE successfully completed the engineering, commissioning, and optimization of more than 2000 base stations. This was done in only 13 months. Such speed in network construction is unprecedented in Hong Kong and a new industry record was set. Coverage quality was increased to 6dBm—even better than that of the 900MHz GSM network.

In cooperation with China Unicom, ZTE provides high-power, multi-carrier, energy-efficient RRUs, in line with China’s energy conservation and emissions reduction goals. In areas with sufficient fiber optic resources, we provide an innovative super-baseband cluster solution that lowers network construction and operation costs significantly. This satisfies the need for quick and cost-effective network construction, but also conforms to the trend of broadband, intelligent mobile networks. BBUs are installed in a centralized way and RRUs deployed remotely with fiber for flexible coverage. This method of deployment represents a revolution in the conventional network model. It shortens the length of a project by a third, and reduces power consumption by up to 85%. Energy-saving network construction was successfully carried out for Dalian Unicom, whose fiber optic resources are abundant.

To keep pace with mobile Internet and to gain a competitive advantage in China’s 3G market, China Unicom and ZTE joined hands to research and test HSPA+. In the second half of 2009, ZTE began testing HSPA+ 64QAM. The results of field testing in Shenzhen showed that the average data rate for indoor subscribers was 19.97Mbps and the average data rate for outdoor subscribers was 18Mbps. These results approach the theoretical maximum data rate of 21Mbps.

In Europe, ZTE was the first to launch MIMO-based transceivers. The company made inroads into the Hungarian market with the world’s first MIMO-based transceivers. SDR multimode multiband distributed base stations were supplied to Telenor Hungary for the construction of a flat, simplified mobile network suitable for the coming 4G era.

J: Energy-saving mobile networks are not only effective in reducing costs and increasing profit, but also demonstrate social responsibility and ensure sustained development. What technological breakthroughs or achievements has ZTE made in this respect?

Pu: In the context of global energy saving and environmental protection, the highly competitive telecom industry also feels the pressure to reduce energy consumption. ZTE has been committed to developing energy-saving technologies since 2006, and has led the industry in power amplification efficiency since 2008. With power efficiency rates of 40% in 2009 and 45% in 2010, ZTE is the forerunner of energy saving within the industry. Combining power amplification efficiency with energy saving techniques—such as voltage regulation, automatic carrier cutoff, and board management—overall network power consumption is significantly reduced.

In the CSL project, our SDR energy-saving base stations and intelligent temperature control technique were used to reduce power consumed by air-conditioning and ventilation systems. This cut down power consumption by 39% (7187 tons of carbon dioxide) annually.

China Unicom has also enjoyed the many benefits of a 3G network constructed by ZTE. Investment in equipment has decreased by 20% (saving up to RMB 600 million); the number of equipment rooms has been decreased (saving up to RMB 1 billion on auxiliary facilities); and high-efficiency amplifiers in base stations have reduced power consumption by 45% (saving up to RMB 100 million per year). Overall network construction costs and power consumption have been reduced by 40% and 85% respectively. The project was regarded by China Unicom as a success, to be promoted across the country.

J: What are the development trends in the wireless industry? What plans has ZTE made regarding future wireless technologies and products?

Pu: Data-oriented, broadband, multimode converged networks are an inevitable trend in the wireless communications industry. Yet operators are still puzzled about what technologies to focus on: GSM EDGE, HSPA+, LTE, or even other families of wireless standards. As diverse wireless technologies and spectrums are introduced, there is also uncertainty about which technologies to develop, on which frequency bands, and how to develop them.  

So we need to address the issues of broadband multimode RF technology, multimode chips, and spectrum resource sharing and scheduling. We offer not only SDR equipment, but an adaptively evolving smart RAN that helps operators achieve smooth network convergence and evolution. This is still our main focus in technology development.