The present disclosure relates to the field of optical fiber cables. More
specifically, the present disclosure relates to an optical fiber cable with odd number of strength members.
BACKGROUND
[0002] An optical fibre cable plays a pivotal role in today's networking
infrastructure. The optical fiber cable carries data faster than conventional copper cables and has complex designs and intensive underground laying procedures. The demand for uninterrupted and high speed internet is consistently paving a way for new design of the optical fiber cable. Over decades, the consistent development in the optical fiber cable industry leads to innovative cable designs that can accommodate more optical fibers within the current limited duct space.
[0003] The optical fiber cable is designed to have maximum number of optical
fibers, to be easy to access and to be easy to tear and cut whenever required. Transmission of data through optical fiber cable depends on the number of strength members embedded inside the optical fiber cable. Overhead cables provide an unobtrusive, convenient and cost-effective way for data transmission for FTTx aerial drop applications.
[0004] In addition, the overhead cables clamped and hunged between poles
during installation. However, the inclusion of robust tensile strength, resistance
2

to breakage and a host of other mechanical features are vital. Further, the strength members are embedded inside the overhead cable sheath. The embedded strength members provide mechanical stability to the overhead cable but resists bending of the overhead cable to some extent. The cable exhibits preferential bending characteristics in case of even number of strength members embedded symmetrically in the sheath of the cable. The even numbers of strength members makes the overhead cable handling less comfortable.
[0005] There are a few patent applications which provide an optical fiber cable
with odd number of strength members. In an example, the patent application WO2019128473A1 shows cable with three strength members but does not mention about bending stiffness characteristics. In another example, the patent application EP0227326A2 shows cable with three strength members but does not mention about bending stiffness characteristics. In yet another example, the patent US6459837B1 shows cable with one strength members but do not mention about bending stiffness characteristics.
[0006] In the light of the above stated discussion, there is a need to ameliorate
one or more of the aforementioned disadvantages by providing a low weight optical fiber with odd number of strength members.
OBJECT OF THE DISCLOSURE
[0007] A primary object of the present disclosure is to provide a low weight
optical fiber cable.

[0008] Another object of the present disclosure is to provide the optical fiber
cable with an odd number of strength members to increase flexibility and improve handling of the optical fiber cable.
SUMMARY
[0009] In an aspect, the present disclosure provides an optical fiber cable. The
optical fiber cable includes one or more optical fibers. In addition, the optical fiber cable includes one or more tubular structures such that each tubular structure has at least one optical fiber. Further, the optical fiber cable includes a sheath surrounding the one or more tubular structures. Furthermore, the optical fiber cable includes a plurality of strength members at least partially embedded in the sheath. Moreover, the plurality of strength members in the optical fiber cable are n+1, where n is an even integer to provide better handling of the optical fiber cable.
STATEMENT OF THE DISCLOSURE
[0010] The present disclosure provides an optical fiber cable. The optical
fiber cable includes one or more optical fibers. In addition, the optical fiber cable includes one or more tubular structures such that each tubular structure has at least one optical fiber. Further, the optical fiber cable includes a sheath surrounding the one or more tubular structures. Furthermore, the optical fiber cable includes a plurality of strength members at least partially embedded in the sheath. Moreover, the plurality of strength members in the optical fiber cable are n+1, where n is an even integer to provide better handling of the optical fiber cable.

BRIEF DESCRIPTION OF THE FIGURES
[0011] Having thus described the invention in general terms, reference will
now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
[0012] FIG. 1 illustrates a cross sectional view of an optical fiber cable with
one tubular structure embedding one or more optical fibers, in accordance with an aspect of the present disclosure;
[0013] FIG. 2 illustrates another cross sectional view of the optical fiber cable
with two tubular structures, in accordance with another aspect of the present disclosure; and
[0014] FIG. 3 illustrates yet another cross sectional view of the optical fiber
cable with one or more tubular structures, in accordance with another aspect of the present disclosure.
[0015] It should be noted that the accompanying figures are intended to
present illustrations of exemplary depictions of the present disclosure. These figures are not intended to limit the scope of the present disclosure. It should also be noted that accompanying figures are not necessarily drawn to scale.

DETAILED DESCRIPTION
[0016] Reference in this specification to "one aspect" means that a particular
feature, structure, or characteristic described in connection with the aspect is included in at least one aspect of the present technology. The appearance of the phrase "in one aspect" in various places in the specification are not necessarily all referring to the same aspect, nor are separate or alternative aspects mutually exclusive of other aspects. Moreover, various features are described which may be exhibited by some aspects and not by others. Similarly, various requirements are described which may be requirements for some aspects but no other aspects.
[0017] Reference will now be made in detail to selected aspects of the present
disclosure in conjunction with accompanying figures. The aspects described herein are not intended to limit the scope of the disclosure, and the present disclosure should not be construed as limited to the aspects described. This disclosure may be embodied in different forms without departing from the scope and spirit of the disclosure. It should be understood that the accompanying figures are intended and provided to illustrate aspects of the disclosure described below and are not necessarily drawn to scale. In the drawings, like numbers refer to like elements throughout, and thicknesses and dimensions of some components may be exaggerated for providing better clarity and ease of understanding.
[0018] Moreover, although the following description contains many specifics
for the purposes of illustration, anyone skilled in the art will appreciate that many variations and/or alterations to said details are within the scope of the present technology. Similarly, although many of the features of the present technology are described in terms of each other, or in conjunction with each other, one skilled in the art will appreciate that many of these features can be provided independently of other features. Accordingly, this description of the

present technology is set forth without any loss of generality to, and without imposing limitations upon, the present technology.
[0019] It should be noted that the terms "first", "second", and the like, herein
do not denote any order, ranking, quantity, or importance, but rather are used to distinguish one element from another. Further, the terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
[0020] FIG. 1 illustrates a cross sectional view of an optical fiber cable 100,
in accordance with an aspect of the present disclosure. In general, an optical fiber cable carries information in the form of data between two places using light technology. In an aspect of the present disclosure, the optical fiber cable 100 includes one or more optical fibers 102, one or more tubular structures 104 and a sheath 106 surrounding the one or more tubular structures 104. In addition, the optical fiber cable 100 includes a plurality of strength members 108 and a water swellable tape 110. In an aspect, the plurality of strength members 108 is a brass plated steel wire. In another aspect, the plurality of strength members 108 may or may not be a brass plated steel wire.
[0021] The optical fiber cable 100 includes the one or more optical fibers 102.
The one or more optical fibers 102 extend longitudinally along a length of the optical fiber cable 100. The one or more optical fibers 102 is a fiber used for transmitting information as light pulses from one end to another. In addition, each of the one or more optical fibers 102 is a thin strand of glass or plastic capable of transmitting optical signals. Also, the one or more optical fibers 102 is configured to transmit large amounts of information over long distances with relatively low attenuation. Further, each of the one or more optical fibers 102

includes a core region and a cladding region. The core region is an inner part of an optical fiber and the cladding section is an outer part of the optical fiber. Moreover, the core region is defined by a central longitudinal axis of each of the one or more optical fibers 102. In addition, the cladding region surrounds the core region.
[0022] The core region and the cladding region are formed along the central
longitudinal axis of each of the one or more optical fibers 102. Moreover, the core region and the cladding region are formed during the manufacturing stage of each of the one or more optical fibers 102. The core region has a refractive index which is greater than a refractive index of the cladding region. In an aspect, the core region has a higher refractive index than the cladding region.
[0023] Each of the one or more optical fibers 102 has a diameter of about
200um. In another aspect, the diameter of each of the one or more optical fibers 102 may be 180um, 160um or 140um. In an aspect, each of the one or more optical fibers 102 is a single mode fiber. In another aspect, each of the one or more optical fibers 102 is a multimode fiber.
[0024] The optical fiber cable 100 includes the one or more tubular structures
104. Each of the one or more tubular structures 104 encloses the one or more optical fibers 102. In an example, each of the one or more tubular structures 104 encloses 12 optical fibers (as shown in FIG. 1). The one or more tubular structures tube 104 may enclose any number of optical fibers. In an aspect, each of the one or more tubular structures 104 surrounds the one or more optical fibers 102. The one or more tubular structures 104 cover the one or more optical fibers 102. Each of the one or more tubular structures 104 is a tube for encapsulating the one or more optical fibers 102. The one or more tubular

structures 104 provide support and protection to each of the one or more optical fibers 102 against crush, bend and stretch. In addition, the one or more tubular structures 104 protect the one or more optical fibers 102 and prevent ingression of water inside. Further, the one or more tubular structures 104 is filled with a water blocking gel.
[0025] The optical fiber cable 100 includes the sheath 106. The sheath 106
surrounds the one or more tubular structures 104. In an aspect, the outer sheath 106 is a high density polyethylene (HDPE) jacket. The outer sheath 106 is characterized by a thickness. The thickness of the outer sheath 106 is in the range of 1.5mm to 2mm. In an aspect, the thickness of the sheath 106 may vary. In an aspect, the sheath 106 is black in color. In another aspect, the sheath 106 may be of any color. The sheath 106 layer interacts directly with ambient environment. In addition, the sheath 106 is a sheathing layer.
[0026] FIG. 2 illustrates a cross sectional view of the optical fiber cable 100
with two tubular structures 104, in accordance with an aspect of the present disclosure. The two tubular structures of the one or more tubular structures 104 are such that each of the two tubular structures has at least one optical fiber of the one or more optical fibers 102.
[0027] FIG. 3 illustrates a cross sectional view of the optical fiber cable 100
with a plurality of tubular structures 104, in accordance with an aspect of the present disclosure. The plurality of tubular structures of the one or more tubular structures 104 are such that each of the plurality of tubular structures has at least one optical fiber of the one or more optical fibers 102.

[0028] The one or more optical fibers 102 are enclosed inside the one or more
tubular structures 104. The one or more tubular structures 104 are any of tubes, buffer tubes, loose tubes or micromodules. In addition, the one or more optical fibers 102 inside the optical fiber cable 100 is one of loose fibers, IBRs, flat ribbons and rollable ribbons. The sheath 106 surrounds the one or more tubular structures 104. In an aspect of the present disclosure, the sheath 106 surrounding the one or more tubular structures 104 is made polyethylene. In another aspect of the present disclosure, the sheath 106 surrounding the one or more tubular structures 104 may or may not be made of polyethylene.
[0029] The optical fiber cable 100 includes the plurality of strength members
108 at least partially embedded in the sheath 106. The plurality of strength members 108 are embedded inside the sheath 106. In general, the strength members help preserve the integrity and separation of components in an optical fiber cable. Moreover, the plurality of strength members 108 provides mechanical stability to the optical fiber cable 100. The plurality of strength members 108 lies substantially along a longitudinal axis of the optical fiber cable 100. In addition, the plurality of strength members 108 provides additional tensile strength to the optical fiber cable 100.
[0030] The optical fiber cable 100 includes odd number of the plurality of
strength members 108. In an aspect, the number of the plurality of strength members 108 are defined by n+1, where 'n' is an even integer. In another aspect, the plurality of strength members 108 is at least partially embedded in the sheath 106.
The plurality of strength members 108 are embedded radially and at equal distance from each other. The partially embedded plurality of strength members

108 allows no pair of strength members and center of the optical fiber cable 100 to be coplanar. In an aspect, the ratio of number of one or more tubular structures 104 to the number of the plurality of strength members 108 is either equal to or less than 3.
[0031] The even numbers of the plurality of strength members 108 embedded
symmetrically in the sheath 106 of the optical fiber cable 100 forces the optical fiber cable 100 to exhibit preferential bending characteristics. In an aspect, the optical fiber cable 100 has a preferential bending of less than 2.4. The preferential bending of the optical fiber cable 100 is calculated as the ratio of bending stiffness of the optical fiber cable 100 in any two different bending planes. In an example, the bending stiffness of a plane passing through the centre of the cable and the centre of one of the strength member 108 is 0.06Nm2 and the bending stiffness of a plane perpendicular to the first plane is 0.14Nm2. The preferential bending of the optical fiber cable 100 corresponding to above two planes comes out to be 2. In general, preferential bending refers to the bending of an optical fiber cable only along its longitudinal axis. The optical fiber cable 100 exhibits preferential bending characteristics and handling difficulty when the preferential bending is more than 2.4. The odd number of the plurality of strength members 108 allow non-preferential bending of the optical fiber cable 100. The non-preferential bending of the optical fiber cable 100 allows bending of the optical fiber cable 100 in all directions with lesser stiffness.
[0032] In an aspect of the present disclosure, the one or more optical fibers
102 has a diameter of less than or equal to 215um. In another aspect of the present disclosure, the one or more optical fibers 102 have a fiber diameter of 200um. In yet another aspect of the present disclosure, the one or more optical fibers 102 has a fiber diameter any of 180um, 160um or 140um.

[0033] In an aspect of the present disclosure, the one or more optical fibers
102 have a bend loss less than 0.3dB at 15mm mandrel for 10 turns. In another aspect of the present disclosure, the one or more optical fibers 102 may or may not have a bend loss less than 0.3dB at 15mm mandrel for 10 turns. In an aspect, the optical fiber cable 100 has a maximum bending stiffness of less than or equal to 0.14 Nm2. In general, the bending stiffness is the resistance of any member against bending deformation. In addition, the bending stiffness is calculated as the ratio of total load to the bending deflection. The optical fiber cable 100 becomes stiff and difficult to handle upon when the bending stiffness increases more than 0.14 Nm2.
[0034] In an aspect, the one or more tubular structures 104 have a young's
modulus of less than 600 MPa. In another aspect, the one or more tubular structures 104 may have a different young's modulus. In general, young's modulus is the ratio of uniaxial force per unit surface to the proportional deformation (change in length divided by original length). The young's modulus of less than 600 MPa makes the optical fiber cable 100 easily peelable, easy to install and less breakable upon load. The one or more tubular structures 104 are easily peelable tubes.
[0035] In an aspect, the ratio of optical fiber count in the optical fiber cable
100 to the outer diameter of the optical fiber cable 100 is greater than 2. The reduction in the ratio of optical fiber count to the outer diameter of the optical fiber cable 100 to less than 2 is not suitable for aerial drop overhead applications. In an aspect, each of the one or more tubular structures 104 has a range of 12 to 24 fibers. In another aspect, each of the one or more tubular structures 104 may have different number of fibers.

[0036] In an aspect, the optical fiber cable 100 is an overhead cable. The
overhead cable is suited to aerial FTTx aerial drop applications. In general, FTTx is any broadband network architecture using optical fiber to provide all or part of local loop used for mile telecommunication. In addition, the overhead cables are clamped and hung between poles during the installation. Further, the overhead cables require inclusion of robust tensile strength and a host of other mechanical features. In an aspect, the aerial cable has a sag of less than or equal to 2%. In general, sag is defined as the vertical difference in level between points of support and the lowest point of the cable sag. In addition, sag is calculated using the formula- S=W*L2/8T, where W is the weight of cable per unit length, L is span length between 2 poles and T is the installation tension.
[0037] In an aspect, each strength member of the plurality of the strength
members 108 has at least 2 wires. In another aspect, each of the plurality of the strength members 108 may have different number of wires. In an aspect, each of the plurality of the strength members 108 has at least 2 brass plated steel wires stranded together. In another aspect, each of the plurality of strength members may have different number of brass plated steel wires stranded together. The stranding of 2 brass plated steel wires to make one strength member 108 provides the desired tensile strength to the optical fiber cable 100. A strength member 108 made of 2 stranded brass plated steel wires possesses a breaking load of around 450N while a strength member 108 made of 3 stranded brass plated steel wires possesses a breaking load of around 650N
[0038] The foregoing descriptions of pre-defined aspects of the present
technology have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present technology to the

precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The aspects were chosen and described in order to best explain the principles of the present technology and its practical application, to thereby enable others skilled in the art to best utilize the present technology and various aspects with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present technology.

WE CLAIMS:

1. An optical fiber cable (100) comprising:
one or more optical fibers (102);
one or more tubular structures (104) such that each tubular structure has at least one optical fiber;
a sheath (106) surrounding the one or more tubular structures (104); and
a plurality of strength members (108) at least partially embedded in the sheath (106), wherein the number of strength members of the plurality of strength members (108) are n+1, where n is an even integer.
2. The optical fiber cable (100) as recited in claim 1, wherein no pair of strength members and center of the optical fiber cable (100) are coplanar.
3. The optical fiber cable (100) as recited in claim 1, wherein a ratio of number of tubular structures to number of strength members is less than or equal to 3.
4. The optical fiber cable (100) as recited in claim 1, wherein the one or more optical fibers (102) has a diameter of less than or equal to 215um.
5. The optical fiber cable (100) as recited in claim 5, wherein the one or more optical fibers (102) have bend loss < 0.3dB at 15mm mandrel for 10 turns.
6. The optical fiber cable (100) as recited in claim 1, wherein the optical fiber cable (100) has a preferential bending of less than 2.4, the preferential bending is the ratio of bending stiffness of the cable in any two different bending planes.

7. The optical fiber cable (100) as recited in claim 1, wherein the optical fiber cable (100) has a bending stiffness of less than or equal to 0.14Nm2
8. The optical fiber cable (100) as recited in claim 1, wherein the one or more tubular structures (104) have a young's modulus of less than 600MPa.
9. The optical fiber cable (100) as recited in claim 1, wherein the ratio of optical fiber count in the optical fiber cable (100) and the cable outer diameter is greater than 2.
10. The optical fiber cable (100) as recited in claim 1, wherein the optical fiber cable (100) has a sag of less than or equal to 2%.
11. The optical fiber cable (100) as recited in claim 1, wherein each strength member has at least 2 brass plated steel wires stranded together.