
5G researchers manage record connection speed - ericthegoodking
http://www.bbc.co.uk/news/technology-31622297
======
vmarsy
"We need to bring end-to-end latency down to below one millisecond"

The incredible bandwidth is surely great but they don't mention how to improve
latency here, they forget to tell what was the latency of this 100m transfer
from an antenna to a receiver.

One of the big issues with today apps is latency, this is easily frustrating.
It also prevents apps such as real time multiplayer games to be viable.

~~~
jessriedel
As a user, my impressions is that the latency involved with routing mobile
data around is a lot higher (more like a second, even with LTE) than the
latency involved with the physical transmission. Mobile data connections are
generally more reliable than WiFi, but usually there is a significant lag
before results are returned. Is that not correct?

~~~
GenerocUsername
This matches my personal experience with tethering being my main internet
connection outside of work/office internet

------
simonebrunozzi
Latency, latency, latency. Everything else is pretty much irrelevant at this
point.

------
femto
It's a simulation [1]. The claim is that the technique is applicable to center
frequencies below 6GHz and the 1Tbit/s used a bandwidth of 100MHz (for a
spectral efficiency of 10^7 bit/s/Hz???). I'm guessing that whilst the
technique might be applicable below 6Ghz, the 1TB/s rate isn't.

There are fundamental limits on the information capacity of an antenna using
the EM spectrum [2], based on the surface area of the volume of space it
occupies, in units of wavelength. (Related to the Holographic Principle?) I
haven't done the calculation, to see if the claimed rate is within this limit,
but a spectral efficiency of 10^7 bit/s/Hz is about 5 orders of magnitude
beyond what others have reported (less than 100bit/s/Hz [3]). It will be
interesting to see the details!

[1] [http://www.ispreview.co.uk/index.php/2015/02/university-
of-s...](http://www.ispreview.co.uk/index.php/2015/02/university-of-surrey-
claims-1tbps-speed-over-future-5g-mobile-tech.html)

"UPDATE 25th Feb 2015

We’ve been finding the 1Tbps claim a little difficult to digest and so have
been prodding Professor Rahim Tafazolli for further details, specifically a
greater clarification of how the performance was achieved.

According to Tafazolli, the new class of Detector (a completely new approach)
was tested through computer simulations (these simulated a real
mobile/wireless environment) and were found to achieve the 1Tbps rate claimed.
In our view that’s quite a bit different from conducting a practical test.

Next year Tafazolli said that his team would work to implement this in a
proper hardware/software platform and test it in a real environment in the
5GIC outdoor testbed. Hopefully they will be able to announce the performance
in 2017."

[2] [http://arxiv.org/pdf/cs/0701055.pdf](http://arxiv.org/pdf/cs/0701055.pdf)

[3]
[http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=tru...](http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&arnumber=6381034)

------
jblow
I don't even get 4G speeds almost ever. Bandwidth is always massively
oversold. Often I can't even successfully load a random web page when I have
4+ bars of "4G".

~~~
rayiner
[http://www.speedtest.net/my-result/i/1154366377](http://www.speedtest.net/my-
result/i/1154366377).

Just posted 22/9 40ms ping in DC Union Station. It's 7pm and the place is
packed with people playing on their cell phones while waiting. Maybe blame SF
NIMBYs for not letting the cell companies put up enough towers or run enough
fiber backhaul?

~~~
ngoldbaum
To be fair, I've seen ISPs give special treatment for packets coming from
speedtest.net. I'm looking at you Comcast.

~~~
irishcoffee
Yes I've noticed the same thing. I ended up rolling my own test just to
verify. I wish I was surprised comcast does this, but they totally do.

------
nikanj
I wonder if we'll still be stuck with our puny data caps when this arrives.
Blowing through your monthly quota in a minute might be astounding from a
technical point of view, but it only takes one broken page with an ajax
infinite loop to get you.

~~~
adventured
If you look out to 2020, and assume 5G will be ready, what you'll get in
production is nowhere near 1tbps. You might see 500mbps - 1gbps commonly
deployed across the US and Europe during the 2020-2025 time frame. Deploying
the initial infrastructure was very expensive, but now it's in place. That's
part of the reason why the US was able to transition relatively quickly to 4G
LTE, there was no need to build 200,000 towers again.

Data caps will rise substantially over the next five years. By 2020x, they'll
be commonly at several hundred gigabytes at 5G speeds across the US and
Europe, with unlimited data at lower speeds as a universal feature. No doubt
numerous carriers will offer variations of unlimited data.

~~~
FireBeyond
You're entirely optimistic, I fear:

"One of the new AT&T plans will cost $25 per month and offer two gigabytes of
data per month, which AT&T says will be enough for 98 percent of its smart
phone customers. Additional gigabytes will cost $10 each."

This is in 2010.

Today that $25 will actually get you HALF the data it did in 2010, five years
ago.

~~~
irishcoffee
This is why I buy phones outright to keep my unlimited data plan from verizon.
I tether it for my home internet as well, usually use between 80-100gb/month.

I'm waiting for the day they just take it away.

