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.
In Europe ,
the allocation of frequency spectrum is as follows: 1900 MHz ~ 1980MHz, 2010
MHz ~ 2025MHz and 2110 MHz ~ 2170MHz, totaling 155 MHz.
The situation in North
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.
In Japan , 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
communications.
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 America , the
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.
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
2) America : Uplink
1850 MHz ~ 1910 MHz and downlink 1930 MHz ~ 1990 MHz.
3) America : 1910
MHz ~ 1930 MHz in both the uplink and the downlink
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 China are
listed below:
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.
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