From our Japan correspondent John Boyd:
While cell phone users in the United States may just be starting to explore 3G mobile phone services, their Japanese counterparts are veterans and have for some time been making good use of sophisticated applications such as ones that turn their mobiles into convenient wallet phone to make electronic cash purchases and credit card payments. So whatâ''s the next big thing, they ask?
If NTT DoCoMo, Japanâ''s biggest cell phone network operator, has its way, the answer is Super 3G, a major upgrade for UMTS, a widely used third generation cell phone technology. DoCoMo has taken on something of a leading role in promoting Super 3G inside the 3G Partnership Project (3GPP) a consortium of wireless operators and vendors, including Vodafone, Lucent, Motorola, and Nokia, working to create global specifications for 3G technologies. Essentially, Super 3G is targeting a useable download transmission speed of around 100 Mbps, with an uplink speed of 50 Mbps, and reaching much higher peak speeds in both cases.
At CEATEC DoCoMo gave its first public demonstration of the technology that is still under development and which is not expected to be deployed until 2010. Taking up a major chunk of DoCoMoâ''s large pavilion, the Super 3G demo consists of a streaming server supplying video content to a prototype Base Station developed by Fujitsu. The base station is capable of a peak download transmission speed of around 900 Mbps using multiple input multiple output (MIMO): a technology that multiplexes different data streams using multiple antennas for transmitting and receiving on the same frequency.
The Base Station is connected by wireless to what DoCoMo calls a Mobile Station, a large cabinet full of electronic components that one day will be whittled way down in size and morphed into a Super 3G handset. However, this was the only segment in the system to actually use wireless connectivity, everything else being wired for the demonstration.
Still, the result was impressive, with DoCoMo achieving a steady download data throughput of 200 Mbps over a bandwidth of only 20 MHz using a 4 x4 MIMO arrangement (four transmitting and four receiving antennas) while control latency between idle and active states was just 100 milliseconds.
To show what a throughput of 200 Mbps (300 Mbps at peak) can do, DoCoMo streamed the data into twelve separate channels and displayed the results on twelve monitors. Nine of these displayed separate videos in H.264 format for a combined capacity of 25 Mbps, while the other three monitors displayed videos in the MPEG2 format for a combined 185 Mbps, with the total throughput reaching approximately 200 Mbps. Simultaneously, a video conference set-up employing the uplink mode was used to transmit live video of the attendees viewing the demonstration at a transmission rate of about 25 Mbps.
Super 3G represents a break with the current 3G infrastructure, so it will require a new round of heavy investment before it can be deployed. Thatâ''s the bad news. The good news is that the same infrastructure can be used for future 4G systems. As a DoCoMo staffer said, â''We see Super 3G as being a bridge to 4G.â'' And one that Japanese users no doubt will be the first to step across.