We are right in the turning point of the mobile telecommunication system and service on the globe.
We've been providing mobile telecommunication service mainly based on voice with analogue Methods. On the other hand, with skyrocketing increasing need for wireless communication, we had to develop telecommunication method to accommodate many service users within allocated RF band. Accordingly, the research and development on digital methods have already been made to increase the efficiency of frequency, so various kinds of multi-contact system such as TDMA, CDMA or Hybrid has been adopted.
To solve the problem with the global roaming service and market formation due to the existing varied system of standard worldwide, ITU plays a great role in the global standardization of mobile telecommunication method.
In an effort to this, ITU has been going ahead with the global standardization, allocating the frequency (1885Mhz~2025Mhz & 2110Mhz~2200Mhz) commonly used worldwide for the purpose of IMT-2000 at the forum of WARC-92 in 1992.