Fiber Drop Cable for FTTH Solution

FTTH Drop Cable definition

Drop cable as an important part of FTTH network forms the final external link between the subscriber and the feeder cable. As it is used in outdoor, drop cable shall have a minimum pull strength of 1335 Newtons according to the industry standard. Drop cables are available in many different types. The following part introduces three most used drop cables divided according to the cable structure.

• Flat Type Drop Cable, also known as flat drop cable, with a flat out-looking, usually consists of a polyethylene jacket, several fibers and two dielectric strength members to give high crush resistance. Drop cable usually contains one or two fibers, however, drop cable with fiber counts up to 12 or more is also available now. The following picture shows the cross section of a flat drop cable with 2 fibers.
• Figure-8 Aerial Drop Cable is self-supporting cable, with the cable fixed to a steel wire, designed for easy and economical aerial installation for outdoor applications. This type of drop cable is fixed to a steel wire as showed in the following picture. Typical fiber counts of figure-8 Drop Cable are 2 to 48. Tensile load is typically 6000 Newtons.
• Round Drop Cable usually contains a single bend-insensitive fiber buffered and surrounded by dielectric strength members and an outer jacket, which can provide durability and reliability in the drop segment of the network.

FTTH Drop Cable Specification

Parameter	Unit	Value
Crush (short term)	N/100 mm	500
Strength member		FRP
Storage temperature	°C	-20 to 60
Installation temperature	°C	-5 to 50
Operating temperature	°C	-20 to 60
Primary buffer diameter	µm	250
Fiber count	n	1 to 4
Nominal outer diameter	mm	2.0 x 3.0 ± 0.2
Nominal weight	kg/km	7
Maximum tensile load	N	80
Minimum bend radius (installation)	mm	44
Minimum bend radius (installed)	mm	25
Jacket material		LSZH
Drum Length	m	2

• Choice of fiber types
• Single mode optical fiber meting ITU-T G.657A1 or ITU-T G.657A2
• Individually colored optical fibers, (blue, orange, green, brown)
• Notched 2 x 3 mm construction for easy stripping
• White LSZH jacket for internal use
• Black LSZH jacket for short distance external use
• Compact cable construction
• FRP strength member
• Conforms to IEC standard

Drop cable as the final connection from the fiber optic network to customer premises also plays an important role. Thus, finding a flexible, efficient and economical drop cable connectivity method becomes a crucial part of broadband service. Whether to use a fiber optic connector, which can be easily mated and un-mated by hand or a splice, which is a permanent joint?

Generally, splice is recommended for drop cables in the places where no future fiber rearrangement is necessary, like a greenfield, new construction application where the service provider can easily install all of the drop cables. Fiber optic connector is appropriate for applications which flexibility is required, like ONTs which have a connector interface.

For splice, there are two methods, one is fusion splicing, the other is mechanical splicing. Fusion splicers have been proved to provide a high quality splice with low insertion loss and reflection. However, the initial capital expenditures, maintenance costs and slow installation speed of fusion splicing hinder its status as the preferred solution in many cases. Mechanical splicing is widely used in FTTH drop cable installation in countries, as a mechanical splice can be finished in the field by hand using simple hand tools and cheap mechanical splicer (showed in the following picture) within 2 minutes. It’s a commonly used method in many places, like China, Japan and Korea. However, in US mechanical splicing is not popular.

For fiber optic connector, there are two types connector for drop cable connection.

• Field terminated connector, which contains fuse-on connector and mechanical connector, and pre-terminated drop cable, which is factory terminated with connector on the end of drop cable.
• Fuse-on connector uses the same technology as fusion splicing to provide the high optical connection performance. However, it requires expensive equipment and highly trained technician, and more time like fusion splicing. Mechanical connector could be a replacement of fuse-on connect if the conditions do not fit the mentioned ones. It could be a time-save and cost-save solution for drop cable termination.

If you have no limits in cost and want high performance termination in a time-save way, pre-terminated drop cable could be your choice. Many factories can provide you customized drop cables in various fiber types, fiber optic connector and lengths.

Multi Tube Steel Armored cables are a strong, Industrial grade FO cable with strong Mechanical protection. With an external PE Jacket, the cable is perfect for Direct Burial applications and offers optimum protection against UV. With each core capable of holding up to 12 cores, Multitube FO Cables can accommodate a maximum of 288 Fibers and can be built for OS2, OM1, OM2, OM3, OM4 or OM5 depending on client requirement.

We provide the most used types of drop cables, see the picture below.
Various types of FTTH drop cables