<s>
10G-PON	B-Protocol
(	O
also	O
known	O
as	O
XG-PON	B-Protocol
or	O
G.987	O
)	O
is	O
a	O
2010	O
computer	B-Architecture
networking	I-Architecture
standard	O
for	O
data	O
links	O
,	O
capable	O
of	O
delivering	O
shared	O
Internet	O
access	O
rates	O
up	O
to	O
10Gbit/s	O
(	O
gigabits	O
per	O
second	O
)	O
over	O
existing	O
dark	B-Protocol
fiber	I-Protocol
.	O
</s>
<s>
This	O
is	O
the	O
ITU-T	O
'	O
s	O
next	O
generation	O
standard	O
following	O
on	O
from	O
GPON	B-Architecture
or	O
Gigabit-capable	O
PON	O
.	O
</s>
<s>
Optical	B-Architecture
fibre	I-Architecture
is	O
shared	O
by	O
many	O
subscribers	O
in	O
a	O
network	O
known	O
as	O
FTTx	B-Architecture
in	O
a	O
way	O
that	O
centralises	O
most	O
of	O
the	O
telecommunications	O
equipment	O
,	O
often	O
displacing	O
copper	O
phone	O
lines	O
that	O
connect	O
premises	O
to	O
the	O
phone	O
exchange	O
.	O
</s>
<s>
Passive	B-Architecture
optical	I-Architecture
network	I-Architecture
(	O
PON	O
)	O
architecture	O
has	O
become	O
a	O
cost-effective	O
way	O
to	O
meet	O
performance	O
demands	O
in	O
access	O
networks	O
,	O
and	O
sometimes	O
also	O
in	O
large	O
optical	O
local	O
networks	O
for	O
"	O
Fibre-to-the-desk	O
"	O
.	O
</s>
<s>
Passive	B-Architecture
optical	I-Architecture
networks	I-Architecture
are	O
used	O
for	O
the	O
"	O
Fibre-to-the-home	O
"	O
or	O
"	O
Fibre-to-the-premises	O
"	O
last	B-Protocol
mile	I-Protocol
with	O
splitters	O
that	O
connect	O
each	O
central	O
transmitter	O
to	O
many	O
subscribers	O
.	O
</s>
<s>
XGS-PON	B-Protocol
is	O
a	O
related	O
technology	O
that	O
can	O
deliver	O
upstream	O
and	O
downstream	O
(	O
symmetrical	O
)	O
speeds	O
of	O
up	O
to	O
10Gbit/s	O
(	O
gigabits	O
per	O
second	O
)	O
.	O
</s>
<s>
ITU-T	O
G.987	O
is	O
the	O
standard	O
for	O
10G-PON	B-Protocol
.	O
</s>
<s>
Asymmetric	O
10G-PON	B-Protocol
is	O
specified	O
as	O
XG-PON1	B-Protocol
:	O
10Gbit/s	O
downstream	O
and	O
2.5Gbit/s	O
upstream	O
(	O
nominal	O
line	O
rate	O
of	O
9.95328Gbit/s	O
downstream	O
and	O
2.48832Gbit/s	O
upstream	O
)	O
.	O
</s>
<s>
Symmetric	O
10G-PON	B-Protocol
is	O
also	O
proposed	O
as	O
XG-PON2	O
with	O
10Gbit/s	O
upstream	O
,	O
but	O
would	O
require	O
more	O
expensive	O
burst-mode	O
lasers	O
on	O
optical	O
network	O
terminals	O
(	O
ONTs	O
)	O
to	O
deliver	O
the	O
upstream	O
transmission	O
speed	O
.	O
</s>
<s>
Another	O
symmetric	O
10G-PON	B-Protocol
standard	O
is	O
XGS-PON	B-Protocol
(	O
ITU-T	O
G.9807.1	O
,	O
approved	O
2016-06-22	O
)	O
.	O
</s>
<s>
Framing	O
is	O
"	O
G-PON	O
like	O
"	O
but	O
uses	O
different	O
wavelengths	O
from	O
G-PON	O
(	O
using	O
a	O
WDM	B-Architecture
to	I-Architecture
separate	I-Architecture
them	I-Architecture
)	O
so	O
that	O
G-PON	O
subscribers	O
can	O
be	O
upgraded	O
to	O
10G-PON	B-Protocol
incrementally	O
while	O
GPON	B-Architecture
users	O
continue	O
on	O
the	O
original	O
OLT	O
.	O
</s>
<s>
This	O
compares	O
to	O
the	O
IEEE	O
802.3av	B-Protocol
standard	O
for	O
10G-EPON	B-Protocol
based	O
on	O
Ethernet	O
,	O
which	O
has	O
standardised	O
upstream	O
rates	O
of	O
both	O
1Gbit/s	O
and	O
10Gbit/s	O
.	O
</s>
<s>
The	O
10	O
Gigabit	B-Architecture
PON	I-Architecture
wavelengths	O
(	O
1577nm	O
down	O
/	O
1270nm	O
up	O
)	O
differ	O
from	O
GPON	B-Architecture
and	O
EPON	O
(	O
1490nm	O
down	O
/1310nm	O
up	O
)	O
,	O
allowing	O
it	O
to	O
coexist	O
on	O
the	O
same	O
fibre	O
with	O
either	O
of	O
the	O
Gigabit	B-Architecture
PONs	I-Architecture
.	O
</s>
<s>
ITU-T	O
Recommendation	O
G.987	O
is	O
a	O
family	O
that	O
defines	O
this	O
access	O
network	O
standard	O
(	O
referred	O
to	O
as	O
XG-PON	B-Protocol
)	O
.	O
</s>
<s>
G.987	O
:	O
10-Gigabit-capable	O
passive	B-Architecture
optical	I-Architecture
network	I-Architecture
(	O
XG-PON	B-Protocol
)	O
systems	O
:	O
Definitions	O
,	O
Abbreviations	O
,	O
and	O
Acronyms	O
,	O
2010	O
.	O
</s>
<s>
G.987.1	O
:	O
General	O
requirements	O
of	O
10G-PON	B-Protocol
systems	O
(	O
approved	O
2010-01-13	O
)	O
.	O
</s>
<s>
Describes	O
a	O
flexible	O
optical	B-Architecture
fibre	I-Architecture
access	O
network	O
representing	O
an	O
evolutionary	O
development	O
from	O
G.984.2	O
,	O
asymmetric	O
only	O
in	O
the	O
current	O
version	O
.	O
</s>
<s>
The	O
optical	O
network	O
unit	O
(	O
ONU	O
)	O
supplies	O
network	O
services	O
from	O
the	O
PON	O
to	O
customer	B-Protocol
premises	I-Protocol
,	O
connecting	O
customer-premises	O
equipment	O
such	O
as	O
a	O
home	B-Application
gateway	I-Application
or	O
office	O
firewall	B-Application
.	O
</s>
<s>
An	O
optical	O
network	O
terminal	O
(	O
ONT	O
)	O
is	O
an	O
ONU	O
that	O
functions	O
as	O
a	O
demarcation	B-Architecture
point	I-Architecture
servicing	O
a	O
single	O
subscriber	O
;	O
e.g.	O
,	O
a	O
dwelling	O
or	O
office	O
.	O
</s>
<s>
ONU	O
devices	O
supply	O
Ethernet	O
and	O
possibly	O
other	O
services	O
to	O
the	O
users	O
,	O
either	O
directly	O
(	O
by	O
bridging	B-Protocol
)	O
or	O
through	O
a	O
gateway	O
device	O
such	O
as	O
a	O
residential	B-Application
gateway	I-Application
,	O
firewall	B-Application
,	O
and/or	O
router	B-Protocol
,	O
POTS	O
,	O
CATV	B-Protocol
signals	O
to	O
buildings	O
wired	O
for	O
RF	O
video	O
,	O
and	O
some	O
may	O
even	O
be	O
compatible	O
with	O
the	O
emerging	O
G.hn	B-General_Concept
home	O
networking	O
standard	O
.	O
</s>
<s>
A	O
specialised	O
Cellular	O
Backhaul	B-General_Concept
Unit	O
(	O
CBU	O
)	O
can	O
provide	O
PON	O
access	O
for	O
cellular	O
networks	O
.	O
</s>
<s>
The	O
OLT	O
(	O
Optical	B-Protocol
Line	I-Protocol
Terminal	I-Protocol
)	O
connects	O
the	O
PON	O
to	O
aggregated	O
backhaul	B-General_Concept
uplinks	O
,	O
allocates	O
time	O
slots	O
for	O
ONUs	O
and	O
ONTs	O
to	O
transmit	O
upstream	O
data	O
,	O
and	O
transmits	O
shared	O
downstream	O
data	O
in	O
broadcast-mode	O
over	O
the	O
PON	O
to	O
users	O
.	O
</s>
<s>
Since	O
10GPON	B-Protocol
is	O
designed	O
to	O
coexist	O
with	O
GPON	B-Architecture
devices	O
,	O
migration	O
to	O
a	O
10GPON	B-Protocol
capability	O
could	O
be	O
done	O
by	O
upgrading	O
the	O
OLT	O
and	O
then	O
migrating	O
individual	O
ONUs	O
as	O
needed	O
.	O
</s>
<s>
Normally	O
the	O
OLT	O
is	O
on	O
a	O
card	O
that	O
slots	O
into	O
an	O
OLT	O
chassis	O
at	O
the	O
Central	O
Office	O
(	O
CO	O
)	O
,	O
which	O
uses	O
special	O
uplink	O
cards	O
for	O
Ethernet	O
backhaul	B-General_Concept
to	O
the	O
telecommunications	O
provider	O
's	O
network	O
and	O
internet	O
.	O
</s>
<s>
Uplink	O
cards	O
on	O
access	O
equipment	O
will	O
likely	O
use	O
multiple	O
Ethernet	O
interfaces	O
,	O
although	O
it	O
remains	O
to	O
be	O
seen	O
what	O
uplink	O
speeds	O
manufacturers	O
will	O
offer	O
to	O
support	O
10GPON	B-Protocol
access	O
.	O
</s>
<s>
PON	O
Optical	O
Distribution	O
Networks	O
use	O
single-mode	B-Device
optical	I-Device
fibre	I-Device
in	O
the	O
outside	O
plant	O
,	O
optical	O
splitters	O
and	O
optical	O
distribution	O
frames	O
,	O
duplexed	O
so	O
that	O
both	O
upstream	O
and	O
downstream	O
share	O
the	O
same	O
fibre	O
on	O
separate	O
wavelengths	O
.	O
</s>
<s>
10G-PON	B-Protocol
is	O
no	O
exception	O
with	O
similar	O
reach	O
to	O
previous	O
standards	O
but	O
supporting	O
a	O
higher	O
split	O
ratio	O
of	O
128	O
users	O
per	O
PON	O
,	O
or	O
more	O
using	O
reach	O
extenders/amplifiers	O
.	O
</s>
<s>
Optical	O
splitters	O
creating	O
a	O
point	B-General_Concept
to	I-General_Concept
multipoint	I-General_Concept
topology	O
are	O
also	O
the	O
same	O
technology	O
as	O
those	O
used	O
by	O
other	O
PON	O
systems	O
.	O
</s>
<s>
Some	O
ONTs	O
can	O
receive	O
a	O
broad	O
range	O
of	O
optical	O
spectrum	O
from	O
1480nm	O
to	O
1580nm	O
,	O
so	O
making	O
the	O
10G-PON	B-Protocol
downstream	O
signal	O
visible	O
to	O
G-PON	O
receivers	O
.	O
</s>
<s>
In	O
October	O
2010	O
,	O
Portugal	O
Telecom	O
reported	O
a	O
successful	O
field	O
trial	O
of	O
10G-PON	B-Protocol
,	O
transmitting	O
3D-TV	O
content	O
using	O
XG-PON1	B-Protocol
capabilities	O
.	O
</s>
<s>
also	O
successfully	O
completed	O
a	O
field	O
trial	O
of	O
the	O
pre-standard	O
XG-PON2	O
(	O
synchronous	O
10G-PON	B-Protocol
)	O
capable	O
of	O
delivering	O
a	O
10Gbit/s	O
broadband	O
connection	O
both	O
downstream	O
and	O
upstream	O
.	O
</s>
<s>
In	O
October	O
2010	O
,	O
at	O
a	O
Verizon	O
customer	O
's	O
business	O
in	O
Taunton	O
,	O
Mass.	O
,	O
the	O
XG-PON2	O
trial	O
used	O
the	O
same	O
optical	B-Architecture
fibre	I-Architecture
that	O
provides	O
that	O
business	O
with	O
its	O
existing	O
FiOS	O
network	O
connection	O
and	O
services	O
.	O
</s>
<s>
BT	O
in	O
the	O
UK	O
is	O
providing	O
a	O
trial	O
10-Gbit/s	O
broadband	O
service	O
to	O
a	O
business	O
customer	O
in	O
Cornwall	O
using	O
XGPON	B-Protocol
technology	O
,	O
it	O
announced	O
on	O
23rd	O
Nov	O
2012	O
.	O
</s>
<s>
Chorus	O
in	O
New	O
Zealand	O
is	O
providing	O
a	O
trial	O
10-Gbit/s	O
broadband	O
service	O
to	O
customers	O
using	O
XGS-PON	B-Protocol
technology	O
.	O
</s>
<s>
OpenFiber	O
(	O
wholesale-only	O
FTTH	B-Architecture
carrier	O
in	O
Italy	O
)	O
has	O
successfully	O
trialled	O
a	O
10Gbit	O
service	O
with	O
coexisting	O
GPON	B-Architecture
on	O
the	O
same	O
fiber	O
,	O
using	O
XGS-PON	B-Protocol
technology	O
from	O
ZTE	O
,	O
on	O
March	O
14	O
,	O
2019	O
in	O
collaboration	O
with	O
ISP	O
Fibra.city	O
.	O
</s>
<s>
Telecom	O
Italia	O
is	O
starting	O
a	O
trial	O
on	O
three	O
exchanges	O
in	O
Italy	O
using	O
XGS-PON	B-Protocol
equipment	O
from	O
Nokia	O
,	O
both	O
to	O
its	O
retail	O
customers	O
and	O
to	O
its	O
wholesale	O
clients	O
.	O
</s>
