TD-SCDMA, as the third-generation mobile communication standard (referred to as 3G) proposed by China, has been formally submitted to the ITU (International Telecommunication Union) since 1998, after more than 10 years, completed a series of international standardization work, such as expert group evaluation of the standard, ITU endorsement and release, convergence with the 3GPP (third-generation partnership project) system, and the introduction of new technical features, thus enabling TD-SCDMA to be used as the third-generation mobile communication standard in China. The standardization work has made the TD-SCDMA standard become the first international standard for wireless communications proposed by China, with China's intellectual property rights as the main focus, and widely accepted and recognized in the international arena. This is an important milestone in the history of China's telecommunications. (Note: There are three international standards for 3G***, the other two being the US-led CDMA2000, and the European-led WCDMA.)
TD-SCDMA's development process
Early in 1998, under the direct leadership of the Department of Science and Technology of the Ministry of Posts and Telecommunications at that time, the Institute of Telecommunication Science and Technology (ITST) organized a team to study and draft China's TD-SCDMA draft proposal in line with IMT-2000 requirements. The draft standard, with smart antenna, synchronous code division multiple access, relay switching, and time division duplex as its main features, was submitted to ITU on June 30, 1998, the deadline of ITU's solicitation for IMT-2000 third-generation mobile communication wireless transmission technology candidates, and thus became one of the 15 candidates for IMT-2000.ITU synthesized the results of the evaluation of the assessment groups, and submitted the draft to the ITU on November 1999 at Helsinki ITU-2000, and then to the ITU on June 30, 1998 at Helsinki. At the 18th meeting of ITU-RTG8/1 in Helsinki in November 1999 and at the ITU-R Plenary in Istanbul in May 2000, TD-SCDMA was formally admitted as one of the programs for the CDMATDD standard.
CWTS (China Wireless Telecommunication Standards Study Group), as a regional standardization organization representing China, after joining the 3GPP in May 1999, after 4 months of thorough preparation and a lot of coordinated work with the 3GPP PCG (Project Coordination Group) and TSG (Technical Specification Group), it proposed to the 3GPP in September the same year to include TD-SCDMA in the 3GPP standard specification work. in December 1999 at the 3GPP meeting in Nice, France, our proposal was accepted by the 3GPPTSGRAN (radio access network) plenary, formally determined to incorporate TD-SCDMA into the Release 2000 (later split into R4 and R5) work plan, and TD-SCDMA was abbreviated as LCRTDD ( Low Code Chip Rate TDD scheme).
After more than a year of discussions in dozens of working group meetings and hundreds of submissions, the first goal of TD-SCDMA convergence in 3GPP was reached at the March 2001 RAN plenary in Palm Springs with the official release of the 3GPPR4 version of the specification, which included the TD-SCDMA standard.
So far, TD-SCDMA has been recognized and accepted by the majority of operators and equipment manufacturers in the international arena, both in form and substance, forming a true international standard.
Status of the TD-SCDMA standard
Since the release of the 3GPPR4 in March 2001, the substantive work of the TD-SCDMA standard specification has been completed mainly under the 3GPP system. In more than two years after the release of the R4 standard, Datang, together with many other industry operators and equipment manufacturers, has gone through countless meeting discussions and mail group discussions, and through a large number of manuscripts submitted, the contents of the physical layer processing, high-level protocol stack messages, network and interface signaling messages, RF indexes and parameters, and conformance tests, etc., of the TD-SCDMA standard specification were revised and improved over and over again, so that the content of the standard specification obtained so far has been improved and revised. The TD-SCDMAR4 specification has been revised and improved so that the TD-SCDMAR4 specification so far has reached a fairly stable and mature level.
Under the framework of 3GPP, after the convergence and improvement, all the technical features and advantages of TD-SCDMA can be reflected in the physical layer of the air interface due to the difference of duplexing mode. The difference in physical layer technology is the main difference between TD-SCDMA and WCDMA. In the core network, TD-SCDMA and WCDMA use exactly the same standard specification, including the core network and radio access network using the same Iu interface; in the air interface high-level protocol stack, TD-SCDMA and WCDMA are also identical. These ****similarities ensure seamless roaming between the two systems, switching, consistency of service support, QoS guarantees, etc., but also ensure that TD-SCDMA and WCDMA in the subsequent development of the standard technology to maintain considerable consistency.
January 20, 2006 has been announced as China's national communications standard. (Note: the statement is not accurate. January 20, the State Ministry of Information Industry for industry standards, rather than the national communications standards)
TD-SCDMA standard subsequent development
In the booming development of 3G technology and systems, whether it is a variety of equipment manufacturers, carriers, or research institutions, the government, the ITU, have already begun to 3G after the development of technology direction of research. The ITU has identified several technological developments in the direction of 3G. In the ITU identified several technology development direction, including smart antenna technology and TDD time division duplex technology, that these two technologies are the trend of future technology development, and smart antenna and TDD time division duplex technology, the two technologies, in the current TD-SCDMA standard system has been well embodied and applied, from this point, can also see TD-SCDMA standard technology has considerable prospects for development. The TD-SCDMA standard has a promising future.
In addition, in the 3GPP releases after R4, the TD-SCDMA standard also introduced new technical features to varying degrees to further improve system performance, including: synchronization between base stations through the air interface, as a base station synchronization as a back-up solution, especially for emergency situations to ensure the reliability of the communication network; terminal location Terminal positioning function, through the smart antenna, the use of signal arrival angle of the end-user location positioning, in order to better provide location-based services; high-speed downlink packet access, the use of hybrid automatic retransmission, adaptive modulation and coding, to achieve high-speed downlink packet service support; multi-antenna input and output technology (MIMO), the use of multi-antenna technology for base stations and terminals, and signal processing, to improve the performance of the wireless system; uplink enhancement technology, using adaptive modulation and coding, hybrid ARQ technology, rapid allocation of dedicated/***-enjoyed resources and the corresponding physical layer and high-level signaling support mechanisms to enhance the uplink channel and service capabilities.
With the full support of the government and operators, the TD-SCDMA industry alliance and industry chain have been basically established, and product development has been further promoted, with more and more equipment manufacturers putting their efforts into the development of TD-SCDMA products. With the large-scale development of equipment and field trials, the TD-SCDMA standard is bound to be further verified and strengthened.
In order to accelerate the industrialization process of TD-SCDMA, and to form a complete industrial chain and a multi-vendor supply environment as soon as possible, the TD-SCDMA Industry Alliance was established in Beijing on Oct. 30, 2002, and the member enterprises of the TD-SCDMA Industry Alliance have developed from the initial 7 enterprises to the current 30 enterprises, which cover the TD-SCDMA industrial chain from system, chip, terminal to test instrument, chip, terminal and test instrumentation.
The nature of the alliance:
TD-SCDMA Industry Alliance is a social organization voluntarily formed by the enterprises and institutions that are actively engaged in the cause of TD-SCDMA, and engaged in the research, development, production, manufacturing and service of TD-SCDMA standard and products.
Purpose of the Alliance:
Integrate and coordinate industrial resources, enhance the research and development, production and manufacturing level of mobile communication enterprises in the Alliance, promote the rapid and healthy development of the TD-SCDMA communication industry, and realize the promotion and application of TD-SCDMA in China and the global communication market.
Scope of business of the alliance:
TD-SCDMA Industry Alliance mainly focuses on TD-SCDMA technology to promote and improve the standard as well as the management and coordination of the industry, to promote the resource *** enjoyment and mutual benefit among enterprises, to suggest that the government formulate major industrial policies conducive to the development of TD-SCDMA, and to enhance the competitiveness of the group of communication enterprises within the alliance.
The TD-SCDMA Industry Alliance carries out a unified intellectual property management policy within the alliance, and highly enjoys technical and market information, and promotes the rapid and healthy development of the TD-SCDMA industry through close communication and reasonable division of labor.
Members of the Alliance:
Telecommunication Science and Technology Research Institute (Datang Telecom Technology and Industry Group)
Huali Group Limited
Huawei Technologies Limited
Lenovo (Beijing) Company Limited
Shenzhen Zhongxingxin Telecommunications Co.
China Putian Information Industry Group Corporation
Beijing Tianqi Technology Co.
Chongqing Heavy Postal Service Co.
Haixin Group Co.
Kemin Information Technology Co.
Xi'an Haitian Antenna Technology Co.
Beijing Zhongchuang Xintest Technology Co.
Hubei Zhongyou Science and Technology Industry Co.
Shanghai Bell Alcatel Co.
Shanghai Dibit Industrial Co.
UT-STARKON
Invada (Shanghai) Electronics Co.
Zhongshan City, China Tongyu Telecommunications Equipment Co.
Qingdao Haier Communication Co.
Shanghai Cortex Century Technology Co.
Beijing StarHub Communication Software Co.
Jingxin Communication Technology (Guangzhou) Co. Ningbo Waveguide Corporation
Chinese Electronics Technology Group Corporation 41st Research Institute
Yiyang Xintong Co.
Shenzhen Changfang Network Technology Co. Ltd.
Advantages and Disadvantages of China's TD and U.S. and European Switching Technologies
Advantages
1. High spectrum utilization TD 1.6M W 10M W
2. Low power control requirements TD 0~200MZ W 1500MZ (Note: but the power control rate is very slow)
3. Adoption of smart antenna and joint detection Introduction of the so-called air classification, but the power control rate is very slow. Introduced the so-called air classification, but the effect of how to be verified (Note: smart antenna can not be used)
4. Avoid the breathing effect of TD different services on the size of the coverage area has less impact on the network planning
Drawbacks:
1. synchronization requirements of high TD [1] need to be synchronized GPS synchronization, synchronization of the accuracy of the degree of the impact of the whole system is working normally
2.
2. Limited code resources TD only 16 codes, far less than the number of codes required by the service demand
3. Interference problems upstream and downstream, the cell, the neighboring cells may have interference
4. Slow speed TD 120KM/H W 500KM/H
5. Relay switching the measured drop rate is comparable to the hard switching
6.