Seize the Opportunity for Great Breakthroughs

An interview with Wang Xiyu, Vice President of ZTE Wireless Product R&D Institute

The year 2009 was the birth year of 3G in China, and also a year for ZTE to make great achievements in wireless business. The success ZTE has achieved attributes to the market-driven R&D concept it has been adhering to. Since the 3G era, ZTE has been ranked among global mainstream mobile equipment suppliers, and has made massive breakthroughs in the wireless infrastructure equipment sector by firmly seizing the market opportunity to improve its R&D ability. Recently, reporter Fang Li of ZTE TECHNOLOGIES interviewed Wang Xiyu, Vice President of ZTE Wireless Product R&D Institute.

Journalist: At present, cloud computing and Internet of Things (IOT) have become hot topics of insiders and the boundary between communications and IT industry, or even between IT industry and other industries is being broken. How does ZTE view the development of these hot technologies?
Wang Xiyu: Recently, cloud computing becomes a hot topic among insiders. ZTE has also paid great attention to it. Being developed from the IT field, cloud computing focuses on the concept of network-based services and completes storage and computing with cloud services to save operational costs.
With the deepening of the convergence of communications and IT industry, cloud services and cloud storage have been deployed. At the wireless access side, the traditional base station structure can not be replaced by the current cloud computing technology due to the high real-time and high bandwidth requirements at the baseband/RF interface, but the distributed processing idea of cloud computing can gradually be used in the base stations.
IOT has been a focus of attention in Europe and the United States now. Chinese operators have also actively participated in IOT workshops. Compared with the previous communications technology that could solve interaction of billions of people, IOT is introduced to solve interaction of 50 to 100 trillions of objects. IOT is a very important killer service of the existing 3G and future 4G technologies. The application of IOT puts higher requirements not only on mobile bandwidth but also on real-time and reliable wireless transmission. The features of wireless technologies like broadband, IP-based and flat structure are provided to meet these requirements. The wireless signaling system shall also take into account some new scenarios brought about by IOT.
Meanwhile, IOT itself is the convergence of the wireless transmission technology and sensor technology, and also an important expansion of the wireless application technology. ZTE has established IOT product line and related R&D institute based on its RFID products. We hope to rapidly develop advanced technologies and products in the field of IOT by leveraging our wealth of experience in wireless communications.

J: How do you understand technology innovation? Could you tell us about prominent technology innovations ZTE has made in the wireless sector?
Wang: Technology innovation is a driving force to enhance product competitiveness. ZTE, as a latecomer to the mobile communications market, must strive to not only keep up with but also surpass its rivals through technology innovations. In this way, we can break the long-term monopoly by well-known overseas equipment vendors in the telecom market. In other words, whether to survive or die depends on technology innovation.
On the other hand, we should avoid blind pursuit of technology innovations. All technology innovations must be driven by market demands. Those innovations capable of meeting customers’ needs are what we need, while those purely for technology are not what we want.
Wireless technologies have evolved at a tremendous rate since 2000. In the past decade, three generations of wireless communication systems (2G/3G/4G) and more than 10 wireless standards were developed. For a long time, equipment vendors have all adopted one wireless standard for deployment of one type of base stations, which may result in huge investments and OAM difficulties. In China alone, the investments in building mobile base stations have reached hundreds of billions yuan.
Due to the great difference in baseband/RF features of the systems of different wireless standards, the Software Defined Radio (SDR) technology has been found only in labs. ZTE is the first in the industry to adopt the combined “soft baseband” and “hard accelerator” solution to enable baseband sharing among different wireless standards. We have also launched a series of key broadband technologies: wide bandwidth LDMOS and multi-band broadband transceivers to greatly increase the carrier density supported by a single base station, and solve the coexistence problem of multi-standard, multi-band wireless systems.
Based on the SDR base station platform, ZTE took the lead to launch commercial dual-mode GSM/UMTS base stations and multi-mode CDMA/LTE and TD-SCDMA/LTE base stations. The base stations of multiple modes can operate on the same physical platform that allows for unified management and thus reduces CAPEX and OPEX. Moreover, ZTE has greatly widened the application scope and improved the performance of traditional cellular networks with a great number of innovative technologies regarding air interfaces and radio networking. The soft base stations launched by ZTE have brought a great revolution to the conventional base stations, helping China move from a follower to a leader in the field of mobile communications.
Based on the soft base stations, ZTE has developed a series of technology innovations: it took the lead to put forward and realized the notions of “Super BTS” with large-capacity baseband pool and “O&M Factory”, which have fundamentally changed the construction mode of base stations; it provided SON key functions such as automatic upgrade and automatic configuration for 4G LTE base stations and took the lead to launch automatic network planning and optimization tools for 3G base station systems, which have brought great OPEX savings for operators; it succeeded in developing GoTa―China’s first digital trunking system with independent IPR―based on the SDR base stations, and succeeded in optimizing air interface standards and redefining network architecture to make the access time less than one second and achieve perfect convergence of traditional wireless services with radio trunked services; and it removed the impact of Doppler frequency shift on CDMA to implement Air-to-Ground (ATG) communications across the America.
ZTE has also made innovations in miniaturizing base stations. It launched in succession UMTS/CDMA/TD-SCDMA Remote RF Units (RRU) with the smallest size and lightest weight in the industry, which could be mounted on the wall, fastened to the pole, or placed on top of the tower to meet the installation requirements for various indoor/outdoor scenarios and thus save a great deal of equipment room space. Moreover, the adoption of advanced rack-management technology in the SDR base station has greatly enhanced the system’s fault locating capability and laid a foundation for cost-effective system expansion in the future.
Clock synchronization is quite an important issue in the wireless system. Currently, mobile systems like CDMA2000, WiMAX, China’s home-grown TD-SCDMA and its evolution standard―LTE TDD, are all relying on the synchronous clock reference. Traditional clock reference relied on America GPS. Considering national security, China developed the Beidou navigation positioning and timing system on its own, and now the complete industrial chain is being formed. In addition to GPS, the SDR base station system can also use the home-made Beidou system solution. When necessary, it can switch from the GPS system to the Beidou timing system.
Due to the high costs of equipment and engineering of the satellite receiving system, “IEEE1588V2” is adopted as an alternative to implement precise clock synchronization through the network. Thanks to its unremitting R&D efforts, ZTE succeeded in embedding the innovative IEEE1588V2 protocol into the SDR base stations. ZTE’s self-developed synchronization algorithm can adapt to both new PTN and conventional networks deployed by operators. It supports frequency and phase synchronization, meeting the clock requirements of various wireless systems on the base stations. The synchronization system was commercialized in the network of Hong Kong CSL in 2009. In China Mobile’s TD-SCDMA testing, it reached the 8ns timing accuracy.

J: The year 2009 was the birth year of 3G in China, and also a year for ZTE to make great achievements in wireless business. Would you tell us what breakthroughs ZTE has made in its R&D capabilities behind the continuous expansion of its market share?
Wang: The year 2009 was a year for ZTE to make great breakthroughs in wireless business. Our achievements were made out of years of accumulation. Now we have reached a brand-new height in understanding the whole wireless network framework, core technologies, networking and customer needs. It is because the improvement of our overall capabilities that we can have a clear understanding of market needs and launch industry-leading SDR base station to obtain product competitiveness.
In 2009, we made great efforts to promote the High Performance Product Development (HPPD), which includes planning in advance, systematic thinking, coordinated development, and project management. The implementation of HPPD makes a favorable combination of product planning and product R&D, significantly improving both the speed and quality of R&D. In 2009, the field quality of our wireless products was fundamentally enhanced.
We also made groundbreaking improvements in our platform planning and architecture capabilities. ZTE is one of the few vendors in the industry that can develop a full range of wireless products. The unified platform it has developed can not only save R&D personnel resources but also boost our overall competitiveness in the wireless infrastructure segment.

J: Would you please tell us about ZTE’s patent strategy for the wireless sector?
Wang: There are numerous patents in the telecom industry. Equipment vendors all hold several related patents, including basic patents, by participating in standards drafting and product development. It is unavoidable for them to use each other’s patents. The problem of patent infringement among them can only be solved by signing the patent cross-licensing agreement. Without the equal position to cross license with the other party, one has to solve the problem by paying money or even through legal actions. ZTE attaches great importance to its patent strategy for the wireless sector. To date, it has applied more than 25,000 patents globally, where over 1,700 patents are used for the LTE/SAE field.
Our patent strategy for the wireless field is divided into three stages: from 1999 to 2003, we improved our employees’ IPR awareness and the number of patent applications provided by each wireless product line; from 2003 to 2009, we focused on patent quality and formed the basic IPR defense framework; from 2010 to 2014, we will significantly improve patent quality and develop the patent strategy for certain technical fields, for example, increase the number of basic patents in the 3G and LTE fields.
In general, due to its late start in 2G, ZTE has placed the focus of its patent strategy on 3G/4G and future evolution of wireless technologies. And meanwhile, ZTE enjoys promising prospects in the convergence of 2G/3G/4G networks.

J: Finally, could you talk about the development trend of wireless technologies? What is the consideration of ZTE in this regard?
Wang: The essence for developing wireless technologies is to satisfy the needs for information interaction between people, between objects, and between people and objects. The emergence of new applications like IOT has put new requirements on high availability of wireless data, such as:
■ Higher bandwidth:  LTE and LTE Advanced will provide Gigabit bandwidth. This puts higher requirements on combination efficiency of high-bandwidth spectrum, intra-cell spectrum and inter-cell spectrum. Therefore, Coordinated Multi-Point (CoMP) transmission and carrier aggregation are new focuses of research.
■ Higher real-timeliness: The current transmission delay is difficult to meet the requirements for electronic medical care and real-time experience. In addition to higher wireless transmission rates and higher scheduling efficiency of the base station, high real-timeliness also requires the entire transmission network to reduce transmission delay. Therefore, flat network architecture is a trend that can reduce the number of intermediate transmission and processing nodes being used.
■ Higher reliability: In the future, important data demanding high security, e.g., a vast amount of electronic payments will be transmitted over the wireless network. This needs to ensure data security and reliability. In addition to reliable wireless data transmission, data encryption and decryption are also important in wireless technologies.
Furthermore, operators’ needs for converging multiple networks at low TCO have posed new challenges for the form of base stations and their management. The base stations will be diverse in variety, from traditional macro base stations to Pico/Femto base stations. The development of components will also have great impact on the form of base stations. Nevertheless, wireless base stations will certainly evolve to be smaller, broadband-based, flat-based and collaborative.
To control the future, one has to control the trend. ZTE has taken into full consideration the development of wireless technologies. The market-driven R&D mechanism ensures us to grasp customer needs and trends in the industry. We have established the Wireless Standards Department and the Wireless Pre-R&D Center, and actively joined the international wireless standards organizations to track the development trends of the industry. And meanwhile, we will share with industrial partners our views on wireless development to jointly push forward the technology evolution.