As America struggles with the transition to proper 3G networks, Japan continues to make strides towards the fourth generation of mobile phone networks. In field experiments, NTT DoCoMo, the largest mobile phone operator in Japan, achieved an approximate 5Gbps downlink data rate. That beats previous tests by a factor of two, as DoCoMo managed to achieve 2.5Gbps over a year ago in December 2005. The increase in data rates appeared to be as simple as doubling the number of antennas -- the MIMO technology in use takes advantage of multiple antennas capable of transmitting signals independently: more antennas = more data -- and using a proprietary solution for receiving the signal. So, what are the prospects of the Japanese public getting their hands on a wireless standard that can download up to 640MB per second? Not great, for the moment at least. DoCoMo is planning on releasing its specific findings regarding the technology at 3GSM in Spain: when they do, we'll know more. Until then, just try and keep the drool off the keyboard, ya hear?