NTT DoCoMo's 4G Tests Hit 300Mbps

haunebu writes "'Your brand-spankin'-new 3G phone is nearing obsolesence: NTT DoCoMo reveals the results from a new 4G test system.' says TheFeature. While in a car moving at 30kph, DoCoMo engineers managed a peak throughput of 300Mbps and a sustained transfer rate of 135Mbps with their new variable spreading factor orthogonal frequency code division multiplexing (WSF-OFCDM) downstream technology. Who comes up with these names, and how does Japan manage to stay lightyears ahead of everyone else in wireless?"

WSF-OFCDM?

[FreeHeel]

I don't speak Japanese, but shouldn't the acronym for ariable spreading factor orthogonal frequency code division multiplexing be VSF-OFCDM?

Concentration

[jm92956n]

Might it be partially due to the higher concentration of people? Because the Japanese people live in closer proximity to one another, fewer cell-towers are needed to provide coverage for a comparable amount of people. Therefore, each cell tower can he of higher quality.

WiFi Anyone??

[dukeluke]

After reading this article - it has led me to analyze the benefits of this versus traditional 802.11x and the application of 4G in the broadband arena.

At a proposed sustained rate of 1G, this technology could revolutionize the Internet as we know it today. And, with more and more bandwidth readily available, there will be better multiplayer games online, as well as streaming on-demand cable-like tv off the Net.

I understand that the technology is proposed for gadgets such as a phone or wristwatch that can also watch HDTV - but imagine a world where everyone has a video-phone conference & everyone also has a 1G up/down broadband connection :)

In a word - WOW.

What are the power requirements?

[tstoneman]

Does this need more power? I'm afraid as it is about using cell phones so close to my head (Richard Brandon, owner of Virgin refused to use a cell phone without a headset, and he has done stupider things like trying to balloon around the world!).

I guess the only mitigating factor is that you generally won't be using the 4G features with the phone pressed against your head....

Yes Yes..

[Rytr23]

High speed data is fantastic..but will it prevent me from having dropped calls?

Simple, they want the best, we want the values.

[blanks]

From what I understand (never been to Japan), everyone wants the best coolest *insert random item here*. People will upgrade their phones and other gadgets every month, and get rid of their old ones.

In the US (live in US so cant say the same about other countries), yes people will buy the latest greatest, but will keep it for years, how many people do you know that have cellphones that are 2-3 years old.
People will only upgrade when their gadgets break, or a new technology comes out they really need. so new phones come out slower, and cheaper (cheap = break easy).

No point in rushing out the newest greatest items when people will allways wait.

Doppler

[bsd4me]

Is speeding up like moving farther from your phone company's CO and using DSL? (slower speed)

The faster you are going means the Doppler effect is more pronounced. Wide Doppler ranges can be a pain to deal with in the receiver.

Density of wealth amongst populace

[Peter Cooper]

More specifically, financial density. Japan is the world's second biggest economy, with an economy roughly half that of the US, or three times bigger than the UK, but with only double the population of the UK. Money is also more equally spread between the rich and poor in Japan. This leads to a relatively high monetary density country-wide, meaning lots of people who can afford high-end services.

This would explain why other densely populated counties, like Bangladesh, aren't riding high on the wagon.. it's because Japan is rich, has wealth more fairly disitributed, and has a dense population. Scandinavia also has its wealth more fairly spread between its citizens, and also boasts some of the world's most impressive mass technologies.

Re:How Japan is "lightyears" ahead of us...

[INeededALogin]

Japan is not small. 135 million people, many of which with cell phones that would have to be upgraded.

The country has large cities, but it has 4 large islands that are completely separate. Not to mention the tons of smaller islands and the extreme separation that the different cities have due to mountains.

I think the reason that Japan is light years ahead of us is probably due to the public's desire for this type of technology. Most Japanese use their cell phones for email and web surfing. They want and will pay for faster technology. People in the United States are... they won't.

Re:Your brand-spankin'-new 3G phone

[Paulrothrock]

Once I get a few things out of the way (a wedding, for one), I'm going to work with my township to provide fiber-to-the-home service. The electrical and sewer systems need replaced, so this is a perfect time to future-proof our infrastructure while providing incentives for businesses to move here and services for people. Then I can tell Comcast to suck it, like I've been wanting to do for a long, long time.

Re:their secret is...

[minairia]

This still doesn't answer why the US is so backwards in mobile. There's no reason why we couldn't have Japanese style mobile networks in the US in dense areas like Florida, New York or Chicago and just expand them out to the less populated areas as time goes on. (Even in Japan, in the far outlying areas, there are places without coverage).

Basically, US mobile companies and slow, lazy, inefficient and technologically backwards. They don't want to invest in new technology because they don't have to because they jointly control the market as a monopoly and the cost of entering fresh with new technology is way way too high.

In Japan now, you can have cell phones with four way video conferencing, TV, GPS and a function where you use the phone as an electronic wallet at the store or with vending machines.

Other than finding new ways to explode things in ever more violent ways, the US is slipping behind the curve. I'm no liberal and have nothing against blasting terrorists, etc. but we're going to have to concentrate on other things as well to keep ahead.

DoS

[milamber3]

I don't keep up much on mobile phone tech. so this is probably nothing new but with this kind of speed are we likely to see trojaned phones contributing to Spam remailing and DDoS when they start spreading to the masses and incorporating more user friendly software (read exploit friendly)?

magic numbers?

[Doc Ruby]

"The company said that the test achieved a maximum downstream data rate of 300Mbps ...
The frequency bandwidth[s] for the test [are] 100MHz..."

How do they get 3bits per cycle? Nyquist frequency limits mean 100MHz could optimally carry 50Mbps, not 6 times that in an actual test.

Channel size is the key

[sbraab]

What you never see mentioned is channel size. If you read the article it says that they use a 100MHz wide downlink channel and a 30MHz wide uplink channel. When you consider that in the US current cellular channels run between 1.25 and 5MHz wide and the carriers usually don't have more than 25MHz per market it doesn't seem to make economic sense.

What you really need to look for in radio technology is spectral efficiency or bits per hertz per second. When you do the math this isn't that great of a technology, it just uses big channels.