Radio Access

There are multiple radio access technologies used in IMT. As of WRC-07, the list is:

- CDMA-Direct Spread (Universal Terrestrial Radio Access-UTRA)

- CDMA-Multi Carrier (CDMA2000)

- CDMA TDD (UTRA TDD)

- TDMA Single Carrier (UWC (Universal Wireless Communication)-136)

- FDMA/TDMA (Digital Enhanced Cordless Communications-DECT)

- OFDMA TDD WMAN (WiMAX)

Currently under study are technologies for Long Term Evolution (LTE) and LTE-Advanced (LTE-A.)

A table which provides an overview of the radio access technologies may be found in “Guidelines on the smooth transition of existing mobile networks to IMT-2000 for developing countries (GST)’ and specifically the tables on pages 4 and 6. In Wikipedia, in the article on 3G there is a table labelled “Overview of 3G/IMT-2000 standards” which provides similar information along with links to other Wikipedia articles providing information on the technologies.

ITU-R Recommendation M.1457-8 (May 2009) clause 5 indicates the radio interfaces for the terrestrial component of IMT-2000 as listed above and also indicates that an overview of each radio interface is provided in §§5.1.1, 5.2.1, 5.3.1, 5.4.1, 5.5.1 and 5.6.1 of Recommendation M.1457-8. These clauses already provide a substantial amount of detail. Subsequent text provides additional detail and cross references to the national and regional standards that define these radio access systems. The level of detail in these subsequent sections is relevant to  those who are deeply immersed in the implementation of the technologies, or are doing research and development in their various aspects.

Information on LTE and LTE-A can be found at the ITU-R’s LTE web page. This page includes links to a considerable amount of information on process and procedures for evaluation of a radio access technology. The useful part at the intermediate level is the portion on the LTE workshops:

- 1st Workshop on IMT-Advanced - Kyoto, 22 May 2007 (The presentations can be obtained by following the appropriate links but a TIES account is needed and must be authorized for access to the material.)

- 2nd Workshop on IMT-Advanced - Seoul, 7 October 2008 ( (The presentations can be obtained by following the appropriate links.)

- 3rd Workshop on IMT-Advanced - Dresden, 15 October 2009 (This event had not yet taken place as this web page was being prepared.)