ITU has allocated 230 MHz frequency for the 3G mobile communication system IMT-2000: 1885 MHz ~ 2025MHz in the uplink and 2110v~ 2200 MHz in the downlink. Of them, the frequency range of 1980 MHz ~ 2010 MHz (uplink) and that of 2170 MHz ~ 2200 MHz (downlink) are used for mobile satellite services. As the uplink and the downlink bands are asymmetrical, the use of dual-frequency FDD mode or the single-frequency TDD mode may be considered. This plan was passed in WRC92 and new additional bands were approved on the basis of the WRC-92 in the WRC2000 conference in the year 2000: 806 MHz ~ 960 MHz, 1710 MHz ~ 1885 MHz and 2500 MHz ~ 2690 MHz.
The European Union (EU) also attached great importance to 3G mobile communication systems and the European Telecommunications Standards Institute (ETSI) started the research work of 3G mobile communication standardization as early as over ten years ago and it established a UMTS (Universal Mobile Telecommunication System) Forum that was composed of operators, equipment manufacturers and telecommunication management organizations. In 1995, the technical proposal for frequency spectrum division was submitted formally to the ITU.
the allocation of frequency spectrum is as follows: 1900 MHz ~ 1980MHz, 2010
MHz ~ 2025MHz and 2110 MHz ~ 2170MHz, totaling 155 MHz.
The situation in
America is rather complex, as shown in Figure 1-2. The 1850 MHz ~
1990 MHz band among the 3G low bands has already allocated for PCS use and it
has been divided into two 15 MHz and two 5 MHz bands. Since the PCS service has
already occupied the frequency spectrum of IMT-2000, the uplink band of the
adjusted IMT-2000 even needs to be shared together with the downlink band of
PCS. This kind of arrange is not suitable for the high-transmit and low-receive
configurations of ordinary base stations.
, the frequency band of 1893.5
MHz ~ 1919.6 MHz has already been allocated for PHS use and the 3G bands
totaling 135 MHz (2 × 60 MHz + 15 MHz) are still available: 1920 MHz ~ 1980MHz,
2110 MHz ~ 2170 MHz, 2010 MHz ~ 2025 MHz). At present, Japan is
endeavoring to clear the conflicts with the frequencies for 3G mobile
The WCDMA FDD mode uses the following frequency spectrum (bands other than those specified by 3GPP may also be used): Uplink 1920 MHz ~ 1980 MHz and downlink 2110 MHz ~ 2170 MHz. Each carrier frequency has the 5M band and the duplex spacing is 190 MHz. In
used frequency spectrum is 1850 MHz ~ 1910 MHz in the uplink and 1930 MHz ~
1990 MHz in the downlink and the duplex spacing is 80 MHz. America
The frequency spectrum used by the WCDMA TDD mode (including the high bit rates and the low bit rates) is as follows (bands other than those specified by 3GPP may also be used):
1) Uplink 1900 ~ 1920MHz and 2010 ~ 2025MHz
1850 MHz ~ 1910 MHz and downlink 1930 MHz ~ 1990 MHz. America
MHz ~ 1930 MHz in both the uplink and the downlink America
In special cases (such as the boundary area of two countries), the TDD mode and the FDD mode may coexist in the same frequency band and 3GPP TSG RAN WG4 is currently researching this situation.
There is only the FDD mode in the cdma2000 system and currently there are a total of seven band classes, of which Band Class 6 is the 1920 MHz ~1980 MHz/2110 MHz ~ 2180 MHz band stipulated in IMT-2000.
In China, according to the present radio frequency division, mobile services, fixed services and spatial services are using the 1700 MHz ~ 2300 MHz band, which is currently serving plenty of microwave communication systems and a certain number of wireless location devices. In December 1996, the State Radio Regulatory Committee of P. R. China re-planned and adjusted some terrestrial radio service frequencies of 2 GHz to adapt to the needs of cellular mobile communication development and radio access. However, the frequency spectrum still conflicts with the 3G mobile communication systems, that is, the 1.9 MHz band for public cellular mobile communications and the radio access band have both taken up some of the IMT-2000 bands.
Therefore, the 3G mobile communication systems have to share the limited frequency resources with the existing radio communication systems. With the development of technologies and services, the planning and adjustment of IMT-2000 bands must be well done to stimulate the operators, scientific research organizations/institutions, manufacturers and other bodies to actively develop the 3G mobile communication systems, so as to meet both the short-term and the long-term frequency spectrum needs in China mobile communication development.
The bands allocated for IMT-2000 in
listed below: China
1) Basic operating bands
FDD mode: 1920 MHz ~ 1980MHz/2110 MHz ~ 2170 MHz
TDD mode: 1880 MHz ~ 1920 MHz/2010 MHz ~ 2025 MHz
2) Supplementary operating bands
FDD mode: 1755 MHz ~ 1785 MHz/1850 MHz ~ 1880 MHz
TDD mode: 2300 MHz ~ 2400 MHz, shared together with the wireless location services; both are major services and the sharing standard is to be specially formulated.
3) Operating band for satellite mobile communication systems
1980 MHz ~ 2010 MHz/2170 MHz ~ 2200 MHz.