According to a recent report, DoCoMo is testing a new network standard that could send DVDs to handheld devices in about 10 seconds! The prototype uses a combination of Multiple In Multiple Out (Mimo) technology and a tweaked version of quadrature amplitude modulation (QAM) and is capable of delivering 2.5Gbits/sec to users travelling at 20Km per hour. Mimo, which is used in a the draft 802.11n Wifi standard and turbo versions of existing Wifi products, uses a combination of several antennas and clever processing to boost data rates.
Most current Wifi implementations use up to three antennas on both the base station and client device. The Docomo system uses six on each, says the MIT Technology Review. This might be viable when transmitting to larger client devices, such as Origami ultra-mobiles. But it is unclear whether Docomo can or will implement Mimo on small mobile phones, something already judged impracticable within the industry.
[There are some interesting details about HSDPA and 4G from DoCoMo Here -- Eds]