A team of European researchers have developed
a radio system which is able to deliver
fibre-optic speeds over distances of up to
two kilometres to provide an inexpensive
and quickly deployable alternative to Fibre
to the Home (FTTH).
By Michael Newlands
In January we reported on the
progress being made by the EU-funded
IPHOBAC project which brought
together companies and research institutions
from around Europe to work on
merging optical and radio frequency
technologies ( See New Wireless Technology
Promises Fibre Speeds for up
to One Kilometre January 2009).
Since then the soon-to-finish project
has made major breakthroughs in what
were already record-breaking wireless
transmission speeds, managing to
quadruple spectral efficiency to 2.8 bits
per second per Hz, while reducing the
required bandwidth by half to double
the data rate to 20 Gbps.
Using the millimetre-wave bandwidth
at 57 to 64 GHz, the project has demonstrated
true fibre optic transmission
speeds to 20.1 Gbps within a spectral
bandwidth of 7 GHz. This is sufficient
for a full duplex 10 Gigabit Ethernet
signal to be transmitted in one single
wireless channel.
Project co-ordinator Andreas Stöhr
says this was much better than the
project had aimed for when it was initially
launched, but the development of
a series of revolutionary new photonic
components had enabled more than
doubling the original target.
While operators might be wary of
launching services in the unlicensed
mm wave band because of the danger
of interference, demonstrations of the
IPHOBAC system in licensed spectrum
bands at 71 to 76 GHz and 81 to 86 GHz are now underway.
Stöhr said that unlike with cellular
transmissions there is no need to
worry about radiation. “The output
power here is much lower than with
cellular systems, and as it is a point to
point technology we are not radiating
everywhere, and the transmission is
like a ray of light in the air. And even
if the ray were to touch somebody the
frequency is so high there would be
very low penetration.”
Bridging the last mile between fibreoptic
cables and homes, particularly
in rural areas, is one major potential
application for the system. “Governments
all over Europe are committed
to fibre-optic technology, but
the last mile is the stumbling block,”
says Stöhr. “If you have one million
new FTTH node deployments a year,
which telcos are far away from installing,
you would need 40 years to get
to all the homes in Germany. So there
is a real need for a fast-deployable
alternative.”
The system is also ideal for bridging
breaks in fibre cables and for providing
mobile communications in disaster
recovery scenarios. “Put your
antenna at the fibre cable and your
receivers up to 2 km away and then
you have fibre speeds available for
mobile communications,” he says.
A last demonstration of the technology
is taking place at European
Microwave Week starting in Rome on
September 28.
Source: http://www.policytracker.com
