Huawei Technologies

Transcription

1 Huawei Technologies

2 Expert s Forum China Telecom leading CDMA development with innovative technology 3

3 Huawei Communicate Shen Shaoai is Deputy Director of China Telecom s Mobile Communication Office. She is also a committee member of China Institute of Communications, with rich experience in mobile network development and operations. China Telecom leading CDMA development with innovative technology China Telecom has quickly deployed the world s largest CDMA network with strong new services and subscriber base. As a technological leader with innovative applications, the operator has spurred development in the global CDMA industry by providing more opportunities for players in the value chain. By Shen Shaoai from China Telecom For China Telecom, 2009 marked a milestone in its development. After acquiring the CDMA network f r o m C h i n a Un i c o m, C h i n a Telecom was granted a long-awaited 3G license. It provides China Telecom a golden opportunity to launch full-service operations from a fresh perspective, though it was not without great challenges. During the past year, the China Telecom Group worked together in successfully rolling out, in record time, the world s largest and China s first commercial 3G CDMA network. China Telecom has since offered 3G services under the e surfing brand, becoming a full-service operator. By developing customers through extensive convergence of fixed and mobile services, it successfully ventured into the mobile and full-service operations. So far it has made unprecedented achievements, while greatly promoting the development of CDMA industry. Network development After acquiring the CDMA network, China Telecom quickly completed cutover and started operations smoothly. Building on this, China Telecom implemented an initiative for comprehensive network optimization and quality improvement. A large-scale 3G network upgrade has extended its 3G coverage to 342 cities, 2,055 counties throughout China. All these efforts have translated into an improvement in user experience and network quality. The e surfing brand was hugely popular even at its promotional stage, laying a good foundation for launching Internet mobile phone applications. Taking advantage of the 3G platform, China Telecom has strongly promoted services such as 189 , e surfing LIVE, imusic and Mobile Best Tone, allowing subscribers to easily experience abundant services through mobile terminals, while various personalized products are launched for middle-/high-end subscribers. China Telecom provides international roaming services in both the consumerto- consumer ( C2C) and consumerto-government (C2G) modes so that subscribers can use mobile services in more than 220 countries and regions. China Telecom also actively promotes fixed-mobile convergence to rapidly grow mobile subscribers. In 2009, new CDMA subscribers exceeded 28 million and the total number of CDMA subscribers reached million. China Telecom s rapid CDMA network development has also helped to expand the industry chain of CDMA terminals to include 60 distributors, 40 designers and 3 chip vendors. There were originally only 20 distributors and 6 vendors for CDMA terminals. More than 500 models of 2G 4

4 Expert s Forum China Telecom leading CDMA development with innovative technology CDMA terminals and about 100 models of 3G CDMA terminals are now available on the market. The CDMA Development Group (CDG) granted the 2009 Operator Leadership award to China Telecom, for its leadership in and contribution to the development of the CDMA industry and outstanding achievements in CDMA operations in China. Technology innovation Co-site and co-antenna for 1X and EV-DO To save costs and facilitate EV-DO network deployment, China Telecom has developed a co-site and co-antenna solution for 1X and EV-DO. This solution can effectively eliminate the near-far effect arising when 1X and EV-DO are not sharing the same site, and minimize the interference between the two networks. By using a single site that also supports 1X services, EV-DO services do not require an external combiner, thereby mitigating signal loss. The co-antenna technology can facilitate wireless network planning, project implementation and site selection, effectively reducing the CAPEX and OPEX. LMSD softswitch architecture Among global CDMA operators, China Telecom is the first to deploy a softswitch core network based on legacy mobile station domain (LMSD) on its CDMA network. Through centralized softswitch deployment in provincial capitals, China Telecom s mobile network and PSTN share the softswitch core, while signaling and media streaming of mobile softswitches are carried over IP. This helps flatten the network architecture and realize centralized maintenance and monitoring, which saves on investment, facilitates maintenance and is a solid foundation for further fixed-mobile convergence. The nationwide coverage of China Telecom s softswitch-based mobile core network provides valuable experience for other large-scale commercial deployments of CDMA softswitches. China Telecom has also widely deployed distributed HLRs To save costs and facilitate EV-DO network deployment, China Telecom has developed a co-site and coantenna solution for 1X and EV-DO. This solution can effectively eliminate the near-far effect arising when 1X and EV-DO are not sharing the same site, and minimize the interference between the two networks. on its CDMA core network, implementing centralized user management and service deployment. By separating the service processing function from the user data center and enabling real-time and seamless disaster recovery, China Telecom gains a solid base to provide integrated data centers and differentiated convergent services. Distributed base stations Being a country with a vast and complex terrain, China has experienced profound changes to its urban and rural infrastructure. To improve its network quality effectively, China Telecom has deployed BBU+RRU base stations that are highly integrated with small footprints, easily deployed, and feature low power consumption, flexible networking and strong adaptation with simple subsequent network expansion. China Telecom has gained a lot of experience in innovatively deploying BBU+RRU base stations in many special scenarios. In the sea, desert, rural areas, and high-speed railways, the RRU can be mounted near the antenna, reducing feeder loss and greatly extending forward link coverage. With multiple RRUs sharing a pseudonoise (PN) code, the PN sharing solution solves the challenges arising in two major deployment scenarios. For handling frequent handovers and severe call drops during fast movement along the high-speed rail, the PN sharing solution can effectively reduce the handover and call drop rate. Second, in dense urban areas where resources are limited and it is difficult to optimize neighbor cells, PN sharing can reduce PN usage and make PN planning and neighbor cell planning easier. The BBU pool mainly applies to scenarios such as dense urban areas where abundant fiber resources are available and remote RRU configuration can be provided. Deployment of the BBU pool can save on investment costs, and effectively solve problems such as the lack of sites, high site costs, the inability to construct traditional macro base stations and difficulty in building GPS antenna. Enhanced efficiency and reduced emission China Telecom is committed to social responsibility as a corporate citizen, especially in reducing environmental impact. In its centralized equipment procurement specifications, a green rating system evaluates all vendors in terms of eco-friendliness, taking into account such factors as energy consumption, environmental impact and the application of new energy-efficient technologies. As a result, suppliers have also gone green and improved the efficiency of their equipment. To make the mobile network more eco-friendly, China Telecom has swapped the legacy energy-guzzling equipment for efficient green network equipment. With the latest power amplification and multi-carrier technologies, the green base station consumes less than half of the power used by a legacy base station but provides three times the capacity, reducing not only power consumption, but also the equipment room footprint per traffic unit. C h i n a Te l e c o m h a s rebuilt t h e ventilation and cooling systems in equipment rooms, transforming them into highly efficient smart systems. Coupled with the extensive adoption of distributed base stations and building sites without 5

5 Huawei Communicate equipment rooms and air-conditioners, the energy consumption and costs from its network have been slashed significantly compared to last year. In building its massive CDMA network, China Telecom has done everything possible to ensure that O&M uses less energy with reduced emissions. China Telecom has a range of green specifications for vendors and suppliers, covering the raw materials for equipment production, the logistics system for reusable packaging materials, and the recycling of retired equipment. Now, of all the equipment at China Telecom, 30% were packaged with reusable materials. Wherever possible, China Telecom fully utilizes solar and wind energy to effectively reduce carbon emission, especially in vast and remote regions like Xinjiang, Qinghai and Tibet where solar energy and wind energy are in abundant supply. Joint construction and sharing Joint network construction and sharing can effectively reduce the use of space and power, protect natural resources and landscape, save considerable money and facilitate site selection, while reducing emissions. It has been encouraged both by Chinese governmental regulations and environmentalists alike. China Telecom has been active in cooperating with other operators for joint construction and sharing of mobile network infrastructure in terms of towers, poles, base stations, and transmission lines. Regarding the infrastructure completed by China Telecom in 2009, 60% base station towers was jointly built and shared with other operators, saving over 439 million USD. Solving EV-DO inter-carrier interference C h i n a Te l e c o m h a s s e e n r a p i d development of its 3G services along with an explosive expansion of its subscriber base, thus a single-carrier EV-DO is failing to meet service requirements. Multicarrier EV-DO networks have since been deployed in a number of large cities and China Telecom has also launched largescale commercial trials of EV-DO Rev.B networks to improve operations. For multi-carrier EV-DO Rev.B technology to expediently meet commercial requirements, China Telecom has joined other players in the industry to reduce EV-DO inter-carrier interference to an acceptable range through techniques like optimizing channel filters and suppressing adjacent channel interference. This has also solved the issue of exceptional decline in network throughput due to interference between adjacent carriers. With the deployment of EV-DO Rev.B networks in large cities such as Beijing and Shanghai, subscribers can enjoy a peak downlink rate of 9.3Mbps and the service experience is equivalent to HSPA. This allows China Telecom to maintain its leading position in the Chinese mobile market in terms of 3G network coverage and performance. Applying HA/CCG 3G networks provide the conditions necessary for rapid development of packet data services. Precision management of packet data services helps operators enhance the values of their products. China Telecom has deployed the home agent (HA)/content charging gateway ( C C G ) a c c o rd i n g t o t h e b u s i n e s s requirements and network status. The HA/CCG integrates the home agent function and the content charging function, allowing roaming subscribers to use their home-area services. The HA/ CCG together with the mobile IP (MIP) technology provides subscribers with a better user experience. Hierarchical control and service management are implemented through the introduction of CCGs. Through the content charging capability, tariff and packages can be selected in a manner that is more transparent, flexible and personalized. China Telecom will evolve its CDMA network toward LTE. Over time, China Telecom will greatly contribute to the efforts of all players in the industry to quickly research relevant topics such as interoperability between CDMA and LTE. In the process, China Telecom is sure to secure and hone its competitive edge. Editor: Xu Peng xupeng@huawei.com 6