TELECOMMS
copper access. This can provide
ultrafast ‘fibre-like’ broadband
at a fraction of the cost – giving
operators and consumers the very
best of both worlds.
The success of VDSL2
vectoring – which has proven
that operators still want to retain
copper cabling to prolong the
migration to FTTH networks –
has further encouraged Gfast
developments. Gfast has been
designed to co-exist with VDSL and
allows operators to employ both
technologies in different scenarios,
enabling customers to switch
between the solutions, in line with
enterprising business models.
With approximately 400
million lines of DSL already
installed, network operators are
keen to maximise the speed
and bandwidth of their existing
copper networks to remain
competitive against the network
providers offering full fibre FTTH
networks. The cost of deploying
FTTdp networks with Gfast is
considerably lower than deploying
FTTH networks. Fur thermore,
they provide a better return on
investment, allowing operators
to both market and deliver
ultrafast broadband without
the substantial investment of
deploying their own, totally new-
build, FTTH networks.
Intriguing new
deployment options
One of the key things that
sets Gfast apart from previous
technologies is its flexible use
of power sources. Power can of
course be provided conventionally
at a co-located street cabinet,
within or adjacent to a multi-
tenant or multi-dwelling building.
However, Gfast also introduces
the ability to support reverse
power using the copper drop
wires, to feed power from the
customer premises to the DPU and
is designed to be able to operate
with multiple subscribers.
Gfast also has an impor tant
role as an adjunct to FTTH in
multi-tenant and multi-dwelling
buildings since it can now bring
gigabit-class ser vices to existing
tenants without the need to
rewire an entire building. For new
business or residential tenants
provider supplied CPE can be
supplied even before a Gfast
30 | July 2017
‘One of the
key things
that sets
Gfast apart
from previous
technologies
is its flexible
use of power
sources.’
installation is complete, making
new ser vice introduction invisible
to the user.
Unlike ADSL2 and VDSL2 which
use Frequency Division Duplexing
(FDD), Gfast uses Time Division
Duplexing (TDD) which allows the
ratio of upstream to downstream
data rates to be easily changed as
application requirements evolve.
This will become increasingly
significant as cloud networks
increase in popularity and low
upstream bandwidths begin to
cause a bottleneck for users
sharing large files. This flexibility
enables operators to provide
new ser vices for the connected
home, such as remote video
sur veillance, and consumers
can tailor their upstream to
downstream ratio to best suit
their usage. TDD also provides
power saving functions for Gfast
since many functions of the
transceivers can be turned off
when there is no data to send.
Reduced OpEx
G fa st te c h n o l o g y i s d e si g n e d to
wo r k i n a c u sto m e r se l f- i n sta l l
e nv i ro n me nt , a l l ow i n g se r v i c e
p rov i d e r s to avo i d t h e co st a n d
i n co nve n i e n c e of se n d i n g a
te c h n i c i a n to t h e h o me . W i t h
t h e si mp l i c i t y of i n sta l l at i o n a n d
t h e ve r y re a so n a b l e e q u i p m e nt
co st , co m b i n e d w i t h t h e sav i n g s
o n p owe r fe e d i n g , t h e f i n a n c i a l
b e n ef i t s b e g i n to a d d u p to a
ve r y exc i t i n g p ro p o si t i o n fo r
se r v i c e p rov i d e r s.
G fa s t a l s o s u p p o r t s
ve cto r i n g , re d u c i n g fa r- e n d
s e l f- c ro s s ta l k a n d i nte r fe re n c e
i n o rd e r to b o o s t p e r fo r m a n c e .
C o n s e q u e nt l y , G fa s t i s a b l e
to u t i l i s e 1 0 6 M H z of s p e ct r u m
ove r t h e co p p e r p a i r w i r i n g f ro m
ex i s t i n g te l e p h o n e l i n e s .
While Gfast currently works
with voice services, its future use
is best suited to Voice-over-IP
(VoIP) which is expected to grow
in popularity, reducing the use of
traditional telephone networks and
the need for an analogue receiver.
Accelerating Gfast Adoption
The Broadband Forum has many
programmes designed to speed
up the release of Gfast based
ser vices including the Gfast
cer tification programme, which
recently launched in conjunction
with the University of New
Hampshire InterOperability
Laboratory (UNH-IOL). ARRIS,
Calix, Huawei, Metanoia, Nokia
and Technicolor have worked
with the Broadband Forum and
UNH-IOL to achieve the first Gfast
Device Cer tifications.
These Certifications include
products based on chipsets from
Broadcom, Metanoia and Sckipio,
ensuring service providers will
have choice of products, form
factors, and features. Testing and
certification of Gfast products in
this way will underpin the ability
to deliver next-generation ultrafast
broadband at scale and ensure
that time-to-market is kept as low
as possible.
Alongside this, the Forum has
also launched its Gfast Council,
which brings together the great
and the good of the industry, to
share the experiences that will
facilitate the rapid deployment
of Gfast implementations. The
Council truly is the centre of
expertise for Gfast and is key in
demonstrating to the world how
Gfast fits into the bigger gigabit
broadband picture.
All these measures are
necessary to not only smooth the
way for easy integration of Gfast
into already complex network
architectures but to maximise
interoperability across the world.
Interoperability will boost service
provider confidence in making
the Gfast move and will ensure
competitive pricing as they look
to deliver sustained profitability
while meeting the challenges of
the market. The other benefit of
interoperability is that it will prolong
the life of Gfast in the network.
By enabling operators to
deploy ultrafast broadband
networks cost effect ively, Gfast
unleashes the full potential
of existing copper networks.
By deploying the technology,
operators can extend the
life of their existing network
infrastructures economically,
while boosting broadband
speeds. Giving the speed of FTTH
without the need for professional
installation, Gfast provides a true
alternative to fibre all the way-
based solutions.
For further information visit:
www.broadband-forum.org