Japanese NTT DoCoMo announced on March 26 that it has achieved a downlink transmission speed of 250Mbps over a mobile phone system based on Super 3G, or 3.9G technology, Nikkei Electronics Asia reported.

The announcement represents a significant landmark in DoCoMo's progress toward the maximum downlink transmission speed of 300Mbps for its Super 3G technology, also known as LTE (Long Term Evolution), expected to be commercialized in 2009.

According to a press release by NTT DoCoMo, the field trial has been underway near its R&D laboratory in Yokosuka, southern Tokyo, starting in February 2008. The trial utilizes four MIMO (Multiple-Input Multiple-Output) antennas for base station transmission and conducts mobile station reception in the maximum bandwidth of 20MHz. NTT DoCoMo is expected to present the official results during the CTIA Wireless 2008 convention in Las Vegas starting on April 1.