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Optical fiber infrastructure built-up & maintenance there after is the most difficult part of telecom network.

OFC is laid across country for domestic services & across sea bed for international connectivity.

We will discuss OFC laying and construction practices for domestic connectivity.

Prime components used for OFC infrastructure  ::

a)     HDPE ( high density poly ethylene ) ducts …outer diameter 40mm / inner diameter 33mm.

b)     HDPE couplers

c)      OFC cable drums of 4 kms each

d)     Earthing pit material

e)     Joint chambers

f)        Joint closures

g)     Route markers

h)      Cable blowing machines

a)     HDPE ducts are laid at a depth of 1.5 mtrs from earth surface..number of ducts is decided by business requirements…generally we lay 02 ducts across country side / 06 ducts with in city limits

b)     if depth is less than 1.5 mtrs than to provide protection to these ducts , civil engineering concepts are used i.e RCC/PCC protection , GI pipe protection.

c)      Ducts are available in lengths of 1kms , therefore after every 1 kms HDPE couplers are used to join 02 ducts

d)     RCC joint chambers are installed after every 04 kms…these joint pits are  buried inside ground at a depth of 1mtr…HDPE ducts need to pass through these joint pits.

e)     Earthing pits are fabricated after every 8 kms across route…these pits are laid along with joint chambers.

f)        RCC route markers are installed after every 250mtrs…these route markers are used for route identification in future for maintenance point of view…route markers are of 1.2 mtrs in length…0.8 mrts is inside ground and visible portion is 0.4mtrs with company name…we can see route markers of various operators across highways

g)     optical cable is in drum of 4kms each…this is armoured cable ( having steel jacket ) which prevents from rodent cuts.

Optical cable is blown inside one of HDPE duct with help from cable blowing machine.

Cable is blown from joint chambers to joint chambers across route length.

Jointing after every 4kms takes place and cable joint is kept inside joint closures…these joint closures are kept inside joint chambers…joint closures are connected to earth pits also after every 8kms, this prevents electric shocks during maintenance work ( as cable is armoured )…with in city limits  as cable is laid across foot path / roads / lanes , it is not possible to use armoured cable…we use unarmoured cable in cities.

Cable laying and route construction is a technology in itself , it is not possible to cover all aspects here.

Please refer to attached photos , so as to get basic idea for route construction.

first picture shows HDPE ducts being laid across country side ( 04 ducts )....second picture shows river crossing through pedestrian path-way, GI pipe is clamped and 2 nos of HDPE ducts are pulled inside this pipe.

we need to co-ordinate with various Govt. agencies also so as to get permissions which is known as ROW ( right of way ) permissions.

for detailed information , please contact vsaxena69@hotmail.com