9.3 UMTS Spectrum

The World Administrative Radio Conference (WARC) in 1992 identified two frequency bands in the 2-GHz range for a sum total of 230 MHz for IMT-2000 applications. These bands were from 1885 to 2025 MHz and from 2110 to 2200 MHz. The band is further split up to support several different types of 3G services. One of the most important spectrum allocations is called the terrestrial paired band . This spectrum will be used by operators employing ground-based (as opposed to satellite-based ) base stations and will use frequency division duplexing (FDD) to separate the bidirectional communications between mobile station and base station. The paired bands that have been allocated in Europe and Asia for terrestrial 3G UMTS service are from 1920 to 1980 MHz and from 2110 to 2170 MHz; thus there is 60 MHz of spectrum for communication in each direction.

Another type of UMTS service is envisioned that will use a different radio technique known as time division duplexing (TDD). For TDD systems, the same frequency band can be used for communicating in both directions. The terrestrial unpaired bands are expected to be used by systems using TDD ground-based networks. The frequency allocated for TDD systems is in the range of 1900 to 1920 MHz and from 2010 to 2025 MHz.

Most of the UMTS spectrum in the IMT-2000 range for FDD is available in Europe and many countries in Asia (Japan and Korea). In China this spectrum will be available after existing services within the spectrum are cleared. In the United States the situation is slightly different. The IMT-2000 spectrum is unavailable as it is used by 2G PCS systems. Hence there are two options: a new spectrum is allocated for 3G or existing spectrum has to be reallocated for UMTS deployment. Figure 9-1 shows the IMT-2000 and UMTS spectrum.

Figure 9-1. IMT-2000 spectrum.

The spectrum for UMTS lies between 1900 and 2025 MHz and 2110 to 2200 MHz. Licensing for the spectrum in many countries has been completed. The licensing process has been either via auctions or "beauty contests" ”the process of inviting the existing 2G cellular operators to put forth a proposal and then selecting the best among them. There is no bidding process as is involved in spectrum auctions. Widespread deployment of UMTS networks is expected in 2003 and beyond. NTT DoCoMo's Freedom of Multimedia Access (FOMA) network in Japan is one of the first pre-Release 99 WCDMA networks that is operational today.