Japan’s leading mobile operator by subscribers NTT DoCoMo says it has achieved a downlink transmission rate of 250Mbps over a high speed wireless network designed to test the capabilities of so-called ‘Super 3G’ mobile communications. The cellco has been developing an experimental Super 3G system close to its laboratory in Yokosuka, south of Tokyo. According to local press reports the operator’s field trials are using four Multiple-Input Multiple-Output (MIMO) antennas for base station transmission and mobile reception in the 20MHz bandwidth, the maximum under new Super 3G standards. Super 3G, also known as Long Term Evolution (LTE), is being standardised by the 3rd Generation Partnership Project (3GPP) and core specifications have already been approved for the technology. LTE features low-latency data transmission and high spectrum efficiency, and is seen as a natural successor to HSDPA and HSUPA evolutions of W-CDMA technology.