NTT DoCoMo have announced that a prototype phone has achieved data transfer speeds of 2.5Gbps whilst travelling at 20kph. This is insane! 3G never offered the data rates we were led to believe (which was OK, 'cos we didn't really believe them!). Recently, HSDPA, or 'Super3G' technology has been making news with data transfer speeds of 3.6Mbps (and a theoretical maximum of 14.4Mbps). But this new 4G technology from DoCoMo simply brings tears to the eyes!

Back in 1998, I worked on a European telecoms project that tried to marry ATM with GSM (or a 622Mbps channel to a 9.6kbps channel!). Transferring data over mobile back then was like trying to pump out a lake with a straw. But 2.5Gbps!! This changes everything! Suddenly, mobile servers and true global ubiquitous mobile P2P networks seem a very real possibility.

Read how NTT DoCoMo achieved 2.5Gbps after the jump.

[Source: Slashphone]

How NTT DoCoMo prototype mobile phone achieved 2.5Gbps data transfer rate

Brace yourself for some acronyms!...

DoCoMo achieved a maximum 1Gbps speed in a similar field experiment on May 9, 2005. This time, by increasing the number of MIMO transmission antennas from four to six and by using 64-QAM, data volume per transmission was increased from four bits to six bits. As a result, DoCoMo achieved a maximum speed of 2.5Gbps, which is faster than the International Telecommunication Union Radiocommunication Sector (ITU-R)'s proposed standard.

Frequency spectrum efficiency, which is expressed as information bits per second per Hertz, was also increased from 10 bits per second per Hertz during the last experiment to 25 bits. This figure is the maximum frequency spectrum efficiency for 4G as defined by WINNER.

Building on the success of the field trials, DoCoMo will continue its research and development in order to actively contribute to the global standardization of 4G.

Notes

• MIMO: Multiple-Input Multiple-Output. Data transmission scheme to increase the achievable data rate, in which different data streams are spatially multiplexed using multiple transmitter and receiver antennas on the same frequency.
• QAM: Quadrature Amplitude Modulation. Modulation scheme which conveys data by changing the amplitude and phase. For example, 64QAM transmits one of 64 signal points and conveys six bits per one symbol.
• Spectral efficiency: Defined by the ratio between the transmission data rate and the channel bandwidth. The spectral efficiency of this experiment is 2.5Gbps/100MHz=25bps/Hz.
• WINNER: Wireless world INitiative NEw Radio. WINNER is a EU research project started in January 2004. This project aims to develop a ubiquitous radio system concept based on global requirements for mobile communication systems beyond 3G.