difference between LC and SC

1. Difference between LC/APC and SC/APC connector?
What is difference between LC/APC connector and SC/APC connector?
Please guide.
The difference between LC and SC lies in the size, the handling and the
connector history.
– Size:
LC is half the size of SC (actually, one SC-adapter is exactly the same size as
a duplex LC-adapter), therefore LC is more and more common in central
offices where packing density (number of connections per area) is an
important cost factor.
– Handling:
SC is a true “push-pull-connector ” and LC is a “latched connector”
(although there are very innovative, real “push-pull-LCs” available which
have the same handling capabilities like SC)
– Connector history:
The LC is the “younger” connector of the two, SC is wider spread around the
world but LC is catching up.
Both connectors have the same Insertion Loss and Return Loss capabilities
(these differ between suppliers but not because of the connector standard
itself). Generally it depends where in the network you want to use the
connectors, a connector in a Central Office (which is a professional
environment with professional installers) has totally different needs than a
connector in the end-users appartment.

2. To add some information about the difference on APC versus UPC
To add some information about the difference on APC versus UPC. You will
notice that the connectors, whether they are SC or LC, will be color coded.
Green connectors/bulkheads are for APC, while Blue connectors/bulkheads
are for UPC.
However the main reason for APC, as far as RF overlay is concerned in PON
deployments, is for back reflectance control. Once RF is introduced into the
PON on the 1550nm wavelength, every bulkhead, split and splice introduces
some amount of back reflectance. RF is not very tolerant of this. So APC is
used to drive that reflectance at an angle into the cladding of the fiber instead
of, essentially, a straight back reflectance. APC bulkheads also minimize “air
gaps” between the 2 fibers connected to the bulkhead, which helps limit
reflectance as well.
UPC on the other hand is for a mostly traditional data connection, since it is a
lot more tolerant of back reflectance. Things like IPTV will not see a difference
between APC or UPC connections as it is a data stream. This is why inside a
central office you will see UPC/Blue connections between
routers/switches/softswitches.
In most PON deployments that have an RF overlay, you will see that the OLT
ports will be Blue for UPC connections with a fiber that heads over to a V-OLT
that also has a Blue UPC connection. That V-OLT will also have a Green APC
port for the video feed for ingress. Then there will be a Green APC port for
egress into the PON splitter, since the V-OLT has combined the wavelengths
from the “data” side and the “video” side together.
“LC/APC is better than SC/apc because SC/APC Connector
have high loss .5dB rether then LC/APC connector .3 dB”
All depends on the polishing procedure
On both connectors can achieve less than 0,5 or 0,3 db. The only difference
between SC and LC is on the ferrule. The Ferrule on SC is 2,5mm and on the
LC is 1,25 (half size of the SC).
Supplement on APC and UPC types connectors
There isn’t much difference in the performance between LC/APC and SC/APC.
As Vishal mentioned earlier, the LC type is smaller in size and therefore more
suitable on high density frames. Regarding APC and UPC types, APC
connectors are superior to UPC connectors in this performance category
because of their angle-polished end face geometry. When light is reflected at

3. the connector interface of a UPC connector, it is reflected straight back at the
source, increasing the return loss value. However, when the same signal
passes through the APC connector, the 8° angle causes the reflected light to
be absorbed by the cladding material. UPC connectors are generally deployed
in transport systems designed for digital signal transport, while APC
connectors are preferred for RF video signal transport. The SC/APC type
connector is currently a standard in both inside plant and outside plant
applications.
LC meet the need for high density connections
Above is right there. The LC exists because of the need for high density
connections. I have found the LC with its 1.25 mm ferrule has slightly lower
tolerances resulting in slightly lower losses on the APC and UPC. While the SC
is the standard I do believe the LC will overtake it quite soon. We can achieve
less than a .3 loss when doing an epoxy polish on either an APC or UPC LC
connector.
View: www.fibercasa.com for more information