The Technology Context – B101

GSM to 3G

In the early 1980s, the first generation of mobile phone technology started. There were many incompatible standards like NMT from north Europe, TACS from England, C-450 from West Germany, Radio COM 2000 from France, and RTMI from Italy and so on. They were only from Europe. Users’ mobile phone could not be used on any other network of standards, causing a lot of inconvenience. For this reason, Western European countries considered to develop a unified next-generation mobile phone standard. At the beginning, drafting standards and the development of the preparatory work were managed by CEPT. GSM was the initials of name of the Group of Experts (French: Groupe Spécial Mobile). Later GSM meant Global System for Mobile Communication in order to facilitate the GSM promotion to the world.


During the development, the function of GSM system has been continuously enriched, providing more diverse services. Short Message Service (SMS) provides a convenient inexpensive way of communication. In 1994, GSM was able to provide circuit-switched data and fax services. In 1999, “WAP agreement” enables users to access the Internet through mobile applications. After 2000, General Packet Radio Services (GPRS) made more efficient way to provide data communications. In 2003, EDGE technology provided nearly three G's data communications’ capabilities. At present, 3 GPP Organization is still developing the GSM standard so that they can deploy in large numbers to take advantage of the GSM infrastructure and smooth to the 3G technology evolution. It’s the objective of GSM.

Nowadays Global System for Mobile Communication is a kind of mobile standard which has been used very widely in the world. Over 200 countries and more than 2 billion people are using GSM phones. After the “roaming agreements” was sighed between mobile phone operators, international roaming users become very common. GSM compared to its previous standard, there is the biggest difference that the signaling and voice channels are digital. That’s the reason GSM is seen as a second-generation (G) mobile telephone system. And 3 GPP organizations take the responsibility for the development and maintenance of GSM standard.

The primary sustainable technology objective for mobile standard is 3G technology. Third-generation mobile communication technology refers to UMTS and CDMA2000 as the representative for high-speed data transmission of cellular mobile communication technology. 3G service can transmit voice (call) and data (e-mail, instant messaging, etc.) at the same time. The representative characteristic of 3G is to provide high-speed data services in the general rate of more than several hundred kbps. 3G is standardized by the International Telecommunication Union (ITU) which is the IMT-2000 standard eventual development results. But there are only three standards now. (UMTS, CDMA2000 and TD-SCDMA)

Universal Mobile Telecommunications System (UMTS) is a third-generation mobile phone technology. It uses W-CDMA as the underlying standards and responses to the 3G wireless system for Europe. UMTS sometimes called 3GSM in order to stress that combines 3G technologies and it is the follow-up to the GSM standard. Basically UMTS is the combination of W-CDMA air interface, the mobile applications core part of GSM system, as well as GSM voice coding algorithms. In fact, W-CDMA is just an air interface, and UMTS is used for 3G global mobile communications which can replace GSM. The main difference between UMTS and GSM is the air interface forming Generic Radio Access Network (GeRAN). It can be connected to various backbone networks like the Internet, ISDN, GSM or to a UMTS network. GeRAN includes the three lowest layers of OSI model. The network layer (OSI 3) protocols form the Radio Resource Management protocol (RRM). They manage the bearer channels between the mobile terminals and the fixed network including the handovers.

CDMA2000 is a 3G mobile communications standard. It is a radio interface approved by the International Telecommunication Union ITU's IMT-2000 standard. CDMA2000 has many different types (CDMA2000 1x, CDMA2000 1xRTT, CDMA2000 1xEV). CDMA2000 1xEV (Evolution-development) is the most difficult one. It is CDMA2000 1x added a high data rate (HDR) capability. 1xEV is generally divided into two stages:
CDMA2000 1xEV the first stage, CDMA2000 1xEV-DO (Evolution Data Only) in a wireless channel high-speed data transmission on the data, support downlink (forward link) a maximum data rate of 3.1 Mbps on the uplink (reverse link) to a maximum rate of 1.8 Mbps.
CDMA2000 1xEV the second phase, CDMA2000 1xEV-DV (Evolution-Data and Voice), to support the downlink (forward link data rate to 3.1 Mbps on the uplink (RP-link) rates of up to 1.8 Mbps. XEV-1 DV also supports 1 x voice users, 1xRTT high-speed data users and 1 xEV-DV data users use the same wireless channel operating in parallel.

TD-SCDMA in spectrum utilization, flexibility of business support, frequency flexibility and costs has unique advantages. Base station can receive uplink or downlink signal very easily because upstream and downstream channels are almost the same. Therefore TD-SCDMA using smart antenna technology has inherent advantages and the use of smart antenna technology also provides the advantages of the SDMA. Users can reduce interference, thereby enhancing the spectrum utilization.


3G with the technology bubble is a potential political and financial effect. The auction of 3G licences and radio frequency spectrums is the key thing in the technology bubble. Since that 3G has been trusted that it will be very universal rapidly, the European telecommunications companies invested a total 300 billion Euros in the standardization of norms, the purchase of equipment and development of the market. However, the profit as they expected still could not make a more specific universal 3G. For that reason, developers left without useless 3G licences and liabilities. Many companies abandoned the license and R & D projects in order to reduce debt. Some companies even tried to lawsuit with the government who let the licences.

For a very big country, china is using 3G technology for the sustainable development. One of the 3G standards, TD-SCDMA standard is developed from mainland China. It is proposed from Chinese Academy of Telecommunications Technology (CATT) to the ITU in 29th of June, 1999. The standard combines smart wireless, and software synchronous CDMA radio (SDR) technology into one. In addition, because of China's huge market, the standard is attended by major telecommunications equipment manufacturers. More than half of the global equipment manufacturers have announced their support of TD-SCDMA standard. And TD-SCDMA standard is the latest one compared with the other two standards of 3G. So there will be quite lot spaces for china to improve and develop in the future. And as we all know the Moore’s law, data communications with computer network develop every day. GSM, 3G and even 4G are suitable for sustainable development. Everyone now in the world or in future can benefit this.