Description:TECHNICAL FIELD
[0001] The present disclosure relates to the field of optical fiber cable and, in particular, relates to a micro optical fiber cable for installation in ducts.
BACKGROUND
[0002] Over the last few years, there has been a rapid growth in the use of optical fiber cables. One such type of optical fiber cables are air blown optical fiber cables. These air blown optical fiber cables are used for various indoor-outdoor applications. The air blown optical fiber cables are installed inducts/microduct. Traditionally, the air blown optical fiber cables are installed by blowing the optical fiber cable into a duct/microduct while simultaneously pushing the optical cable into the duct in starting length of cable to support the initial blowing of the optical fiber cable. The blowing is done by injecting a high volume of compressed air into the duct which flows inside the duct at high speed. Accordingly, the high speed air propels the optical fiber cable further inside the duct. The optical fiber cable is blown with a cable blowing machine. Typically, the structure of these air blown optical fiber cables includes a number of buffer tubes. The buffer tubes are stranded around a central strength member in an S-Z fashion. In addition, the buffer tubes are enclosed by a sheathing layer for providing protection to the air blown optical fiber cable. Typically, the buffer tubes are made using polybutylene terephthalate, PA-12 or polypropylene. Further, the buffer tubes are single layer buffer tubes.
[0003] The currently available air blown optical fiber cables have certain drawbacks. The existing air blown optical fiber cables limits blowing distance and speed for installation in smaller ducts due to the large diameter. In addition, the single layer design of the buffer tubes leads to a higher thickness of the buffer tubes. The higher thickness of the buffer tubes results in a large diameter of the buffer tubes. Accordingly, the large diameter of the buffer tubes leads to large diameter of the air blown optical fiber cables. Further, the conventionally available air blown optical fiber cables with large optical fiber diameter results in the large diameter optical fiber cable. This affects the blowing performance of the air blown optical fiber cables into a duct of predefined size. These air blown optical fiber cables with large diameter are very difficult to blow for large distances. Therefore, the conventionally available optical fiber cables of this kind are blown into duct of higher size. Furthermore, the existing optical fiber cables use optical fiber having a diameter of about 200 microns to overall reduce the diameter of the optical fiber cable to serve the purpose of duct size.
[0004] In light of the foregoing discussion, there exists a need for an optical fiber cable which overcomes the above cited drawbacks of conventionally known optical fiber cables.
OBJECT OF THE DISCLOSURE
[0005] A primary object of the disclosure is to provide a micro optical fiber cable for an ease in installation in a micro duct having an inner diameter of 10 mm and an outer diameter of 14 mm.
[0006] Another object of the present disclosure is to optimize the stiffnesss of the optical fiber cable.
[0007] Yet another object of the present disclosure is to optimize the blowing performance of the optical fiber cable.
[0008] Yet another object of the present disclosure is to provide the micro optical fiber cable having a smaller diameter for easy installation.
SUMMARY
[0009] In an aspect, the present disclosure provides an optical fiber cable. The optical fiber cable includes a central strength member lying substantially along a longitudinal axis of the optical fiber cable. The optical fiber cable includes a first layer wrapped helically around the central strength member. The optical fiber cable includes a plurality of buffer tubes stranded helically around the first layer. Each of the plurality of buffer tubes encloses a plurality of optical fibers. The optical fiber cable includes a second layer cross helically positioned around the core of the optical fiber cable. The optical fiber cable includes a third layer wrapped helically around the core of the optical fiber cable. The optical fiber cable includes a fourth layer surrounding the third layer. The optical fiber cable includes a plurality of ripcords. The central strength member is made of fibre reinforced plastic. The central strength member is a solid pultrusion type fibre reinforced plastic. The central strength member has a diameter of about 3 mm. The first layer is a plurality of water swellable yarns. The buffer tube has a first diameter of about 1.55 mm ± 0.05 mm. The buffer tube has a second diameter of about 1.85 mm ± 0.05 mm. The buffer tube is made of a combination of two sub layers having different material. The buffer tube has a first sub layer and a second sub layer. The first sub layer is made of polycarbonate. The first sub layer layer has a thickness of about 75 microns ± 10 microns. The first sub layer has a density of about 1.2 gm/cm3.The first sub layer is the inner sub layer of the buffer tube. The second sub layer is made of polybutylene terephthalate. The second sub layer has a thickness of about 75 microns ± 10 microns. The second sub layer has a density of about 1.31 gm/cm3. The second sub layer is the outer sub layer of the buffer tube. The plurality of buffer tubes being eight. The plurality of optical fibers in each buffer tube being twenty four. Each of the plurality of optical fibers has a diameter of about 250 microns. The second layer is formed of a pair of binder yarns. The pair of binder yarn includes a first binder yarn and a second binder yarn. The first binder yarn being wrapped helically in clockwise direction. The second binder yarn being wrapped helically in anti-clockwise direction. The third layer is a plurality of water swellable yarn. The fourth layer is made of high density polyethylene. The fourth layer has a thickness in the range of about 0.4 mm to 0.6 mm. The fourth layer has a density in the range of about 0.90 gm/cm3 to 0.96 gm/cm3.The plurality of ripcords being positioned between the fourth layer and the third layer. The optical fiber cable has a diameter of about 7.7 mm ± 0.2 mm.
[0010] In an embodiment of the present disclosure, the central strength member is being coated with a polyethylene layer. The central strength member is being coated to accommodate plurality of buffer tubes.
[0011] In an embodiment of the present disclosure, the central strength member is made of a solid pultrusion type fiber reinforced plastic. The central strength member optimizes the stiffness and blowing performance of optical fiber cable.
[0012] In an embodiment of the present disclosure, the first binder yarn and second binder yarn is an aramid type binder yarn.
[0013] In an embodiment of the present disclosure, the binder yarn is water blocking type aramid yarn.
[0014] In an embodiment of the present disclosure, each of the plurality of ripcords is high strength water blocking type yarns.
[0015] In an embodiment of the present disclosure, the plurality of ripcords being positioned between the fourth layer and along with the third layer in linear manner.
[0016] In an embodiment of the present disclosure, the buffer tube has a packing factor in a range of about 75% to 92%.

[0017] In an embodiment of the present disclosure, the optical fiber cable can be blown into a micro duct having an inner diameter of 10 mm and an outer diameter of 14 mm.
[0018] In an embodiment of the present disclosure, the fill factor of the duct is in a range of about 54% to 64%.
STATEMENT OF THE DISCLOSURE
[0019] In an aspect, the present disclosure provides an optical fiber cable. The optical fiber cable includes a central strength member lying substantially along a longitudinal axis of the optical fiber cable. The optical fiber cable includes a first layer wrapped helically around the central strength member. The optical fiber cable includes a plurality of buffer tubes stranded helically around the first layer. Each of the plurality of buffer tubes encloses a plurality of optical fibers. The optical fiber cable includes a second layer cross helically positioned around the core of the optical fiber cable. The optical fiber cable includes a third layer wrapped helically around the core of the optical fiber cable. The optical fiber cable includes a fourth layer surrounding the third layer. The optical fiber cable includes a plurality of ripcords. The central strength member is made of fibre reinforced plastic. The central strength member is a solid pultrusion type fibre reinforced plastic. The central strength member has a diameter of about 3 mm. The first layer is a plurality of water swellable yarns. The buffer tube has a first diameter of about 1.55 mm ± 0.05 mm. The buffer tube has a second diameter of about 1.85 mm ± 0.05 mm. The buffer tube is made of a combination of two sub layers having different material. The buffer tube has a first sub layer and a second sub layer. The first sub layer is made of polycarbonate. The first sub layer layer has a thickness of about 75 microns ± 10 microns. The first sub layer has a density of about 1.2 gm/cm3.The first sub layer is the inner sub layer of the buffer tube. The second sub layer is made of polybutylene terephthalate. The second sub layer has a thickness of about 75 microns ± 10 microns. The second sub layer has a density of about 1.31 gm/cm3. The second sub layer is the outer sub layer of the buffer tube. The plurality of buffer tubes being eight. The plurality of optical fibers in each buffer tube being twenty four. Each of the plurality of optical fibers has a diameter of about 250 microns. The second layer is formed of a pair of binder yarns. The pair of binder yarn includes a first binder yarn and a second binder yarn. The first binder yarn being wrapped helically in clockwise direction. The second binder yarn being wrapped helically in anti-clockwise direction. The third layer is a plurality of water swellable yarn. The fourth layer is made of high density polyethylene. The fourth layer has a thickness in the range of about 0.4 mm to 0.6 mm. The fourth layer has a density in the range of about 0.90 gm/cm3 to 0.96 gm/cm3.The plurality of ripcords being positioned between the fourth layer and the third layer. The optical fiber cable has a diameter of about 7.7 mm ± 0.2 mm.
BRIEF DESCRIPTION OF FIGURES
[0020] Having thus described the disclosure in general terms, reference will now be made to the accompanying figures, wherein:
[0021] FIG. 1 illustrates a cross sectional view of an optical fiber cable, in accordance with an embodiment of the present disclosure.
[0022] FIG. 2 illustrates a cross sectional view of an optical fiber cable, in accordance with another embodiment of the present disclosure.
[0023] It should be noted that the accompanying figures are intended to present illustrations of exemplary embodiments 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
[0024] Reference will now be made in detail to selected embodiments of the present disclosure in conjunction with accompanying figures. The embodiments described herein are not intended to limit the scope of the disclosure, and the present disclosure should not be construed as limited to the embodiments 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 embodiments 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.
[0025] 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.
[0026] FIG. 1 illustrates a cross sectional view of an optical fiber cable 100, in accordance with various embodiments of the present disclosure. The optical fiber cable 100 is a micro optical fiber cable. The optical fiber cable 100 is used for installation in micro ducts. In addition, the optical fiber cable 100 is used for underground installations. Also, the optical fiber cable 100 is used for communication, and the like. In an embodiment of the present disclosure, the optical fiber cable 100 is a 192F micro optical fiber cable. In addition, 192F corresponds to 192 optical fibers. Further, the optical fiber cable 100 has a small diameter which makes the optical fiber cable 100 suitable for installation in the smaller micro ducts.
[0027] The optical fiber cable 100 is made of a plurality of layers (mentioned below in the patent application). The optical fiber cable encloses plurality of buffer tubes each made of two sub layers having different material and thickness. Each buffer tube of the plurality of buffer tubes encloses a plurality of optical fibers. In an embodiment of the present disclosure, the plurality of optical fibers is loosely held inside the each of the plurality of buffer tubes. In an embodiment of the present disclosure, each buffer tube has a small diameter (mentioned below in the patent application). Further, the optical fiber cable 100 has a reduced cable diameter (provided below in the patent application).
[0028] The optical fiber cable 100includes a central strength member 102, a first layer 104,a plurality of buffer tubes 106 and a plurality of optical fibers108. In addition, the optical fiber cable 100 includes a second layer 110, a third layer112 and a fourth layer114. Further, the optical fiber cable 100 includes a plurality of ripcords 116a-116b.
[0029] The optical fiber cable 100 includes the central strength member 102. The central strength member 102 lies substantially along a longitudinal axis of the optical fiber cable 100. In an embodiment of the present disclosure, the central strength member 102is made of fiber reinforced plastic. The central strength member 102 is made of a solid pultrusion type fiber reinforced plastic. The fiber reinforced plastic is a composite material having a polymer matrix reinforced with glass fibers. In an example, the fiber reinforced plastics includes but may not be limited to glass fibers, carbon fibers, aramid fibers, basalt fibers and the like. In another embodiment of the present disclosure, the central strength member 102 is made of any other suitable material. In an embodiment of the present disclosure, the central strength member 102 may be coated with a layer of polyethylene. The central strength member 102 is coated to accommodate the plurality of buffer tubes around it. In another embodiment of the present disclosure, the central strength member may be coated with any other suitable material. In yet another embodiment of the present disclosure, the central strength member 102 may not be coated. In an embodiment of the present disclosure, the central strength member 102 has a circular cross-section.
[0030] The central strength member 102 provides physical strength to the optical fiber cable 100 and resists over bending of the optical fiber cable 100. In addition, the central strength member 102 provides tensile strength to the optical fiber cable 100. The tensile strength corresponds to a resistance shown by the optical fiber cable 100 against longitudinal loads. The central strength member 102 is characterized by a diameter measured along the cross section. In an embodiment of the present disclosure, the diameter of the central strength member 102 is about 3millimeters. In another embodiment of the present disclosure, the diameter of the central strength member 102 may vary.
[0031] The optical fiber cable 100includes the first layer 104. The first layer 104 surrounds the central strength member 102. The first layer 104 includes a plurality of water swellable yarns 104a-104c helically disposed around the central strength member and the plurality of buffer tubes106. The plurality of water swellable yarns 104a-104c prevents ingression of water inside the core of the optical fiber cable 100. In an embodiment of the present disclosure, the number of water swellable yarns present in the first layer 104 is 3. In another embodiment of the present disclosure, the number of water swellable yarns present in the first layer 104 may vary.
[0032] The optical fiber cable 100 includes a plurality buffer tube 106. The plurality of buffer tube 106 is stranded around the first layer 104 in a helical fashion.
[0033] The cross section of each of the plurality of buffer tubes is circular in shape. In an embodiment of the present disclosure, the cross section of each of the plurality of buffer tubes may be of any suitable shape. In an embodiment of the present disclosure, each of the plurality of buffer tubes has a uniform structure and dimensions. In an embodiment of the present disclosure, the plurality of buffer tube 106 includes 8 buffer tubes. Each of the plurality of buffer tube106 is having two sub layers. Two sub layers include a first sub layer and a second sub layer. The first sub layer is the inner sub layer and the second sub layer is the outer sub layer. Each sub layer is made of a different material. Each sub layer has a different thickness. Each sub layer has a different density. The inner sub layer is made of polycarbonate having a density of about 1.2 gm/cm3. In general, polycarbonates are a group of thermoplastic containing carbonate groups in chemical structure. The inner sub layer layer has a thickness of about of about 75 microns ± 10 microns. The outer sub layer is made of polybutylene terephthalate. The second sub layer has a density of about 1.31 gm/cm3. The second sub layer has a thickness of about 75 microns ± 10 microns. In another embodiment of the present disclosure the thickness and density of inner sub layer and outer sub layer may vary.
[0034] Furthermore, each of the plurality of buffer tubes has a first diameter and a second diameter. In an embodiment of the present disclosure, the first diameter and the second diameter of each of the plurality of buffer tubes is fixed. In an embodiment of the present disclosure, the first diameter of each of the plurality buffer tubes is about 1.55 mm ± 0.05 mm. In another embodiment of the present disclosure, the first diameter of each of the plurality of buffer tubes may vary. In an embodiment of the present disclosure, the second diameter of each of the plurality of buffer tubes is about1.85 mm ± 0.05 mm. In another embodiment of the present disclosure, the second diameter of each of the plurality of buffer tubes may vary.
[0035] Going further, each of the plurality of buffer tubes 106 encloses the plurality of optical fibers108. In an embodiment of the present disclosure, each of the plurality of buffer tubes 106 encloses 24 optical fibers. In another embodiment of the present disclosure, each of the plurality of buffer tube encloses 12 optical fibers (as shown in Fig. 2). Each of the plurality of buffer tubes 106 is a tube for encapsulating the plurality of optical fibers 108.The plurality of buffer tubes 106 provides support and protection to each of the plurality of optical fibers 108 against crush, bend and stretch. In addition, the plurality of buffer tubes 106 protects the plurality of optical fibers 108 and prevents ingression of water inside the stranded core of the optical fiber cable 100. Further, each of the plurality of buffer tubes 106 provides mechanical isolation, physical damage protection and identification of each of the plurality of optical fibers 108. Each of the plurality of buffer tubes 106 is colored. In an embodiment of the present disclosure, the color of plurality of buffer tube 106 includes red, green, yellow, brown, blue, purple, grey (slate) and orange. In another embodiment of the present disclosure, the color of each of the plurality of buffer tubes may vary. The coloring is done for identification of each of the plurality of buffer tubes. In an embodiment of the present disclosure, each of the plurality of buffer tubes is filled with a gel. In an embodiment of the present disclosure, the gel is a thixotropic gel. In an embodiment of the present disclosure, the thixotropic gel prevents ingression of water inside each of the plurality of buffer tubes.
[0036] Further, each of the plurality of optical fibers108 is a fiber used for transmitting information as light pulses from one end to another. In addition, each of the plurality of optical fibers108 is a thin strand of glass capable of transmitting optical signals. Also, each of the plurality of optical fibers108 is configured to transmit large amounts of information over long distances with relatively low attenuation. Further, each of the plurality of optical fibers108 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 plurality of optical fibers108. In addition, the cladding region surrounds the core region.
[0037] Each of the plurality of optical fibers108 has a diameter of about 250 microns. In another embodiment of the present disclosure, the diameter of each of the plurality of optical fiber may vary. In an embodiment of the present disclosure, each of the plurality of optical fibers108 is a colored optical fiber. In an embodiment of the present disclosure, each of the plurality of optical fibers108 has a different color. The color of each of the plurality of optical fibers108 is selected from the group. The group include blue, orange, green, brown, slate, yellow, red, violet, white, black, aqua and pink. The group further includes the above color along with a single ring marking. The group further includes the above color along with the double ring marking. The coloring is done for identification of each of the plurality of optical fibers108. In another embodiment of the present disclosure, each of the plurality of optical fibers108 may be of any different color.
[0038] In an embodiment of the present disclosure, a number of the plurality of optical fibers108 in each of the plurality of buffer tubes is 24. In an embodiment of the present disclosure, a total number of the plurality of optical fibers 108 in the plurality of buffer tubes 106 is 192 (8*24 = 192), when the number of buffer tubes is 8. In another embodiment of the present disclosure, a total number of the plurality of optical fibers in the plurality of buffer tubes is 288 (24*12 = 288), when the number of buffer tubes is 24 (as shown in Fig. 2). In yet another embodiment of the present disclosure, the number of optical fibers and the number of buffer tubes in the plurality of buffer tubes 106 may vary.
[0039] In an embodiment of the present disclosure, each of the plurality of optical fibers108 has a fiber attenuation of about 0.35dB/km at a wavelength of about 1310 nanometers. In another embodiment of the present disclosure, each of the plurality of optical fiber 108 has a fiber attenuation of about 0.25 dB/km at a wavelength of 1550nanometers. In yet another embodiment of the present disclosure, each of the plurality of optical fibers 108 has afiber attenuation of about 0.4 dB/km at a wavelength of 1625nanometers. The fiber attenuation corresponds to a loss in optical power as the light travels through the optical fiber. Each of the plurality of optical fiber 108 has a dispersion of less than 0.2 ps/vkm. The dispersion corresponds to a spreading of the optical signals over time.
[0040] The optical fiber cable 100includes the second layer 110. The second layer 110is made of binder yarns. The binder yarn is used for binding of the core of the optical fiber cable 100. In an embodiment of the present disclosure, the binder yam is a normal binder yam. In another embodiment of the present disclosure, the binder yarn is a zero shrinkage binder yam. In yet another embodiment of the present disclosure, the binder yarn is a low shrinkage binder yam. In an embodiment of the present disclosure, the binder yarn is an aramid yarn. In another embodiment of the present disclosure, the binder yarn is made of any other suitable material.
[0041] The optical fiber cable 100 includes the third layer 112. The third layer includes a plurality of water swellable yarns. The plurality of water swellable yarns prevents ingression of water and moisture inside the core of the optical fiber cable 100. In addition, the plurality of water swellable yarns prevents water penetration along the length of the optical fiber cable 100.

[0042] In an embodiment of the present disclosure, the third layer 112 of the optical fiber cable 100 is replaced with water blocking aramid binder yarns. In another embodiment of the present disclosure, the third layer 112 of the optical fiber cable 100 is replaced with water blocking rip cords. The use of water blocking aramid binder yarns and water blocking rip cord prevents ingression of water and moisture inside the core of the optical fiber cable 100.
[0043] The optical fiber cable 100 includes the fourth layer 114. The fourth layer 114 is a sheathing layer. In an embodiment of the present disclosure, the fourth layer 114 is a sheath made of at least one of UV proof black medium density polyethylene material and UV proof black high density polyethylene material. In general, medium density polyethylene is a thermoplastic material produced by chromium/silica catalysts, Ziegler-Natta catalysts or metal locene catalysts. In another embodiment of the present disclosure, the fourth layer 114is made of any other suitable material. The fourth layer 114protects the optical fiber cable 100from harsh environment and harmful UV rays. In addition, the fourth layer 114 has the inherent ability to resist crushes, kinks and tensile stress. In an embodiment of the present disclosure, the fourth layer 114 has a thickness of about 0.5 millimeter. In another embodiment of the present disclosure, the fourth layer 114 may have any suitable thickness.
[0044] The optical fiber cable 100includes the plurality of ripcord 116a-116b. The plurality of ripcord 116a-116b is disposed inside the fourth layer 114 and the third layer 112. In an embodiment of the present disclosure, the plurality of ripcord 116a-116b lies substantially along the longitudinal axis of the optical fiber cable 100. The plurality of ripcord 116a-116b facilitates access to the plurality of optical fibers. In an embodiment of the present disclosure, the plurality of ripcord 116a-116b is made of a polyester material. In another embodiment of the present disclosure, the plurality of ripcord 116a-116b is made of any other suitable material. In an embodiment of the present disclosure, the plurality of ripcord 116a-116b are twisted yarns. In an embodiment of the present disclosure, the number of ripcords in optical fiber cable 100 is 2. In another embodiment of the present disclosure, the number of ripcords may vary.
[0045] In an embodiment of the present disclosure, the plurality of rip cord 116a-116b in the optical fiber cable 100 are replaced by yarns having high strength and water blocking characteristics. The yarns facilitate access to the plurality of optical fibers and prevent ingression of water and moisture inside the core of the optical fiber cable 100.

[0046] In an embodiment of the present disclosure, the optical fiber cable 100 may have a suitable diameter. In an embodiment of the present disclosure, the diameter of the optical fiber cable 100 is in a range of about 7.7 mm ± 0.2 mm. In another embodiment of the present disclosure, the diameter of the optical fiber cable 100 may vary. In an embodiment of the present disclosure, the weight of the optical fiber cable 100 is in a range of about 53 ± 10 kilogram per kilometer. In another embodiment of the present disclosure, the weight of the optical fiber cable 100 may vary.
[0047] In an embodiment of the present disclosure, the buffer tube has a packing factor in a range of about 75% to 92%. Packing factor of buffer tube is defined as the ratio of equivalent cross-sectional area of optical fiber bunch to the cross-sectional area formed by inner diameter of the buffer tube. Equivalent cross-sectional area is the area formed by equivalent diameter of the optical fiber bunch. Equivalent diameter is calculated by using the expression as follows: 1.155* Square Root of number of optical fibers per tube * Diameter of a optical fiber.
[0048] In an embodiment of the present disclosure, the optical fiber cable 100 is blown into a duct having a fill factor in a range of about 54% to 64%. Fill factor is a measure of the acceptability of a cable to be installed in a duct. Fill factor is sometimes defined as the ratio of the cross-sectional area of the cable to the cross-sectional area of the bore of the duct and in the case of a cable and a bore diameter, is sometimes defined as the ratio of the square of cable diameter to square of the bore diameter.
[0049] In an embodiment of the present disclosure, the optical fiber cable 100 has a maximum operation tensile strength of about 1000 Newton. In an embodiment of the present disclosure, the minimum bending radius of the optical fiber cable 100 during installation is 20 D and after installation is 10 D. In an embodiment of the present disclosure, the crush resistance of the optical fiber cable 100 is about 500 Newton per 100 millimeter. In an embodiment of the present disclosure, the impact strength of the optical fiber cable 100is 1 Newton meter. In an embodiment of the present disclosure, the torsion of the optical fiber cable 100is ± 180 degree. In an embodiment of the present disclosure, the temperature performance of the optical fiber cable 100during installation is in the range of -10 degree Celsius to 50 degree Celsius. In an embodiment of the present disclosure, the temperature performance of the optical fiber cable 100during operation is in the range of -30 degree Celsius to 70 degree Celsius. In an embodiment of the present disclosure, the temperature performance of the optical fiber cable 100during storage is in the range of -30 degree Celsius to 70 degree Celsius. In another embodiment of the present disclosure, the optical fiber cable 100 has any suitable value or range of crush resistance, impact strength, torsion, tensile strength, minimum bending radius and temperature performance.
[0050] FIG. 2 illustrates a cross sectional view of an optical fiber cable 200, in accordance with another embodiment of the present disclosure. The optical fiber cable 200 is a 288F micro optical fiber cable. In addition, 288F corresponds to 288 optical fibers. Further, the optical fiber cable 200 has a small diameter which makes the optical fiber cable 200 suitable for installation in the micro ducts.
[0051] The optical fiber cable 200includes a central strength member 202, a first layer 204, a first layer of plurality of buffer tubes 206 and a plurality of optical fibers208. In addition, the optical fiber cable 200 includes a second layer 210, a second layer of plurality of buffer tubes 212 and a plurality of optical fibers214. Further, the optical fiber cable 200 includes a third layer 216, a fourth layer 218, a fifth layer 220 and a plurality of ripcord 222a-222b.
[0052] The optical fiber cable 200 includes the central strength member 202. The central strength member 202 lies substantially along a longitudinal axis of the optical fiber cable 200. In an embodiment of the present disclosure, the central strength member 202is made of fiber reinforced plastic. In an embodiment of the present disclosure, the central strength member 202 may be coated with a layer of polyethylene. The central strength member 202 is characterized by a diameter measured along the cross section. In an embodiment of the present disclosure, the diameter of the central strength member 202 along with the polyethylene coating is about 2.8 millimeters. In another embodiment of the present disclosure, the diameter of the central strength member 202 may vary.
[0053] The optical fiber cable 200 includes the first layer 204. The first layer 204 surrounds the central strength member 202. The first layer 204 includes a plurality of water swellable yarns 204a-204c helically disposed around the central strength member and the first layer of buffer tubes206. The plurality of water swellable yarns 204a-204c prevents ingression of water inside the core of the optical fiber cable 200. In an embodiment of the present disclosure, the number of water swellable yarns present in the first layer 204 is 3. In another embodiment of the present disclosure, the number of water swellable yarns present in the first layer 204 is 5. In yet another embodiment of the present disclosure, the number of water swellable yarns present in the first layer 204 may vary.
[0054] The optical fiber cable 200 includes the first layer of plurality of buffer tubes 206. The first layer of plurality of buffer tubes 206 are stranded around the first layer 204 in a helical fashion. In an embodiment of the present disclosure, the lay length of the first layer of buffer tubes 106 is in a range of about 80 millimeters – 100 millimeters. In general, the lay length is a longitudinal distance along the length of the central strength member 202 required for the plurality of buffer tubes to go all the way around the central strength member 202.
[0055] Each buffer tube of the plurality of buffer tube 206 is same in construction, structure, dimension, color and design as each of the plurality of buffer tube 106(as mentioned in detailed above in the patent application).
[0056] Going further, each of the plurality of buffer tubes 206 encloses the plurality of optical fibers 208. In an embodiment of the present disclosure, each of the plurality of buffer tubes 206 encloses 12 optical fibers. Each of the plurality of buffer tubes 206 is a tube for encapsulating the plurality of optical fibers 208. Each of the plurality of optical fibers 208 has a diameter of about 250 microns.
[0057] In an embodiment of the present disclosure, a number of the plurality of optical fibers 208 in each of the plurality of buffer tubes 206 is 12. In an embodiment of the present disclosure, a total number of the plurality of optical fibers 208 in the first layer of the plurality of buffer tubes 206 is 108 (9*12 = 108), when the number of buffer tubes is 9. Each of the plurality of optical fiber 208 has the same color, properties and dimensions as each of the plurality of optical fiber 108 (as explained in detailed above in the patent application).
[0058] The optical fiber cable 200 includes a second layer 210. The second layer 210 includes a plurality of water swellable yarns. The plurality of water swellable yarns prevents ingression of water inside the core of the optical fiber cable 200. In addition, the water swellable yarns prevent water penetration along the length of the optical fiber cable 200.
[0059] The optical fiber cable 200 includes a second layer of buffer tubes 212. The second layer of the plurality of buffer tubes 212 are stranded around the second layer 210in a helical fashion. In an embodiment of the present disclosure, the lay length of the second layer of buffer tubes 212 is in a range of about 100 millimeters – 140 millimeters. In an embodiment of the present disclosure, the second layer of the plurality of buffer tubes 212 includes 15 buffer tubes.
[0060] Each buffer tube of the plurality of buffer tube 212 is same in construction, structure, dimension, color and design as each of the plurality of buffer tube 106 (as mentioned in detailed above in the patent application).
[0061] Going further, each of the buffer tubes in the second layer of the plurality of buffer tubes 212 encloses the plurality of optical fibers 214. In addition, each of the plurality of buffer tubes 212 encloses 12 optical fibers.
[0062] In an embodiment of the present disclosure, a number of the plurality of optical fibers 214 in each of the plurality of buffer tubes in the second layer of buffer tubes 212 is 12. In an embodiment of the present disclosure, a total number of the plurality of optical fibers 214 in the second layer of buffer tubes 212 is 180 (15*12 = 180) when the number of buffer tubes is 15. Each of the plurality of optial fiber 214 has the same color, properties and dimensions as the plurality of optical fiber 108 (as explained in detailed above in the patent application).
[0063] The total number of optical fibers present in the optical fiber cable 200 is 288 (108+180 = 288). In another embodiment of the present disclosure, the total number of optical fibers present in the optical fiber cable 200 may vary.
[0064] The optical fiber cable 200 includes the third layer 216. The third layer 216 is made of binder yarns. The binder yarn is used for binding of the core of the optical fiber cable 200. In an embodiment of the present disclosure, the binder yam is a normal binder yam. In another embodiment of the present disclosure, the binder yarn is a low shrinkage binder yarn.
[0065] The optical fiber cable 200 includes the fourth layer 218. The fourth layer includes a plurality of water swellable yarns. The plurality of water swellable yarns prevents ingression of water and moisture inside the core of the optical fiber cable 200. In addition, the plurality of water swellable yarns prevents water penetration along the length of the optical fiber cable 200.
[0066] The optical fiber cable 200 includes the fifth layer 220. The fifth layer 220 is a sheathing layer. In an embodiment of the present disclosure, the fifth layer 220 is a sheath made of at least one of UV proof black medium density polyethylene material and UV proof black high density polyethylene material. The fifth layer 220 protects the optical fiber cable 200 from harsh environment and harmful UV rays. In an embodiment of the present disclosure, the fifth layer 220 has a thickness of about 0.5 millimeter. In addition, the fifth layer 220 has the inherent ability to resist crushes, kinks and tensile stress.
[0067] The optical fiber cable 200includes the plurality of ripcord 222a-222b. The plurality of ripcord 222a-222b is disposed between the fifth layer 220 and the fourth layer 218. In an embodiment of the present disclosure, the plurality of ripcord 222a-222b lies substantially along the longitudinal axis of the optical fiber cable 200. The ripcord 222 facilitates access to the plurality of optical fibers.
[0068] In an embodiment of the present disclosure, the optical fiber cable 200 may have a suitable diameter. In an embodiment of the present disclosure, the diameter of the optical fiber cable 200 is in a range of about 9.2 millimeters ± 0.2millimeters. In another embodiment of the present disclosure, the diameter of the optical fiber cable 200 may vary. In an embodiment of the present disclosure, the weight of the optical fiber cable 200 is in a range of about 72 ± 10 kilogram per kilometer. In another embodiment of the present disclosure, the weight of the optical fiber cable 200 may vary.
[0069] In an embodiment of the present disclosure, the optical fiber cable 200 has a maximum operation tensile strength of about 350 Newton. In an embodiment of the present disclosure, the optical fiber cable 200 has a maximum installation tensile strength of about 1250 Newton. In an embodiment of the present disclosure, the minimum bending radius of the optical fiber cable 200 during installation is 20 D and after installation is 10 D. In an embodiment of the present disclosure, the crush resistance of the optical fiber cable 200 is about 700 Newton per 100 millimeter. In an embodiment of the present disclosure, the impact strength of the optical fiber cable 200 is 1 Newton meter. In an embodiment of the present disclosure, the torsion of the optical fiber cable 200 is ± 180 degree. In an embodiment of the present disclosure, the temperature performance of the optical fiber cable 200 during installation is in the range of -30 degree Celsius to 70 degree Celsius. In an embodiment of the present disclosure, the temperature performance of the optical fiber cable 200 during installation is in the range of -10 degree Celsius to 70 degree Celsius. In an embodiment of the present disclosure, the temperature performance of the optical fiber cable 200 during service is in the range of -10 degree Celsius to 70 degree Celsius. In an embodiment of the present disclosure, the temperature performance of the optical fiber cable 200 during storage is in the range of -30 degree Celsius to 70 degree Celsius. In another embodiment of the present disclosure, the optical fiber cable 200 has any suitable value or range of crush resistance, impact strength, torsion, tensile strength, minimum bending radius and temperature performance.

[0070] In an embodiment of the present disclosure, the optical fiber cable 200 with 288 fibers and average diameter of 9.3 millimeter went through one or more tests to check the blowing performance of the optical fiber cable 200. In another embodiment of the present disclosure, a mini optical fiber cable with 288 fibers and average diameter of 10.2 millimeter went through the one or more tests to check the blowing performance of the mini optical fiber cable. In yet another embodiment of the present disclosure, a mini optical fiber cable with 24 fibers and average diameter of 4.3 millimeter went through the one or more tests to check the blowing performance of the mini optical fiber cable.
[0071] In an embodiment of the present disclosure, each of the three cables has to pass one or more pre-defined criteria to pass the test. A first pre-defined criterion of the one or more pre-defined criteria is that the cables should blow all the way in the 2000 meter route. A second pre-defined criterion of the one or more pre-defined criteria is that the route must be completed under 60 minutes. A third pre-defined criterion of the one or more pre-defined criteria is to stop the trial when the speed of blowing is below 20 meter per minute. A fourth pre-defined criterion of the one or more pre-defined criteria is that the cables should be blown out under 60 minutes. A fifth pre-defined criterion of the one or more pre-defined criteria is that no lubricant for the mini cables having less than 144 fibers should be used.
[0072] In an embodiment of the present disclosure, the track used for the testing of the one or more optical fiber cables includes 2 loops. Each loop of the two loops is used to measure 1000 meter in length providing a total track distance of 2000 meter. Further, the track includes three end loops and each end loop is equally spaced at 500 meter. In addition to the end loop, the track includes 14 chambers, 4 chambers of which stimulate two road crossings.
[0073] In an embodiment of the present disclosure, the standard equipment used for the test includes a compressor, a blowing machine, and an air flow meter. The compressor is Kaersar Mobil air M17 fitted with an inline air intercooler. The blowing machine is a CBS air stream C1700. The air flow meter is a suitable in-line air flow meter. Further, a new unused micro duct is used for each of the one or more cable for the consistency with the test results.

[0074] In an embodiment of the present disclosure, one or more blowing equipment was used for the trials. The one or more equipment include a Minijet and a M17 compressor. In an embodiment of the present disclosure, the one or more cables were tested at some predefined distance interval to check the blowing performance of the one or more cables.
[0075] Test Cable 1: 288f mini cable with an average diameter of 9.3mm.
[0076] The first cable for the test includes the optical fiber cable 200. The type of tube used for the optical fiber cable 200is 18/14 mm. The route used for the optical fiber cable 200 includes a distance of 1900 meter. The number of fiber in the optical fiber cable 200is 288. The data corresponding to the test results of the optical fiber cable 200includes distance, time, speed and air flow of the blowing operation.
[0077] The optical fiber cable 200 is blown to a distance of 50 meter in 1.06 minutes with a speed of 60 meter per minute. The optical fiber cable 200 is blown to the next distance from 50 meter to 100 meter in 1.58 minutes with the speed of 59 meter per minutes. The optical fiber cable 200 is blown to the next distance from 100 meter to 150 meter in 2.54 minutes with the speed of 52 meter per minutes. The optical fiber cable 200 is blown to the next distance from 150 meter to 200 meter in 3.58 minutes with the speed of 48 meter per minutes with an air flow of 2 bar. The optical fiber cable 200 is blown to the next distance from 200 meter to 250 meter in 5.05 minutes with the speed of 50 meter per minutes with an air flow of 4 bar. The optical fiber cable 200 is blown to the next distance from 250 meter to 300 meter in 6.04 minutes with the speed of 58 meter per minutes with an air flow of 6 bar. The optical fiber cable 200 is blown to the next distance from 300 meter to 350 meter in 6.58 minutes with the speed of 58 meter per minutes with an air flow of 6 bar. The optical fiber cable 200 is blown to the next distance from 350 meter to 400 meter in 7.54 minutes with the speed of 57 meter per minutes with an air flow of 6 bar. The optical fiber cable 200 is blown to the next distance from 400 meter to 450 meter in 8.53 minutes with the speed of 55 meter per minutes with an air flow of 6 bar. The optical fiber cable 200 is blown to the next distance from 450 meter to 500 meter in 9.53 minutes with the speed of 53 meter per minutes with an air flow of 6 bar. The optical fiber cable 200 is blown to the next distance from 500 meter to 550 meter in 10.55 minutes with the speed of 55 meter per minutes with an air flow of 7 bar. The optical fiber cable 200 is blown to the next distance from 550 meter to 600 meter in 11.55 minutes with the speed of 52 meter per minutes with an air flow of 7 bar. The optical fiber cable 200 is blown to the next distance from 600 meter to 650 meter in 12.48 minutes with the speed of 58 meter per minutes with an air flow of 7 bar. The optical fiber cable 200 is blown to the next distance from 650 meter to 700 meter in 13.49 minutes with the speed of 58 meter per minutes with an air flow of 7 bar. The optical fiber cable 200 is blown to the next distance from 700 meter to 750 meter in 14.47 minutes with the speed of 58 meter per minutes with an air flow of 7 bar. The optical fiber cable 200 is blown to the next distance from 750 meter to 800 meter in 15.47 minutes with the speed of 58 meter per minutes with an air flow of 7 bar. The optical fiber cable 200 is blown to the next distance from 800 meter to 850 meter in 16.47 minutes with the speed of 58 meter per minutes with an air flow of 8 bar. The optical fiber cable 200 is blown to the next distance from 850 meter to 900 meter in 17.46 minutes with the speed of 58 meter per minutes with an air flow of 8 bar. The optical fiber cable 200 is blown to the next distance from 900 meter to 950 meter in 18.47 minutes with the speed of 57 meter per minutes with an air flow of 8 bar. The optical fiber cable 200 is blown to the next distance from 950 meter to 1000 meter in 19.44 minutes with the speed of 56 meter per minutes with an air flow of 8 bar. The optical fiber cable 200 is blown to the next distance from 1000 meter to 1050 meter in 20.44 minutes with the speed of 53 meter per minutes with an air flow of 8 bar. The optical fiber cable 200 is blown to the next distance from 1050 meter to 1100 meter in 21.46 minutes with the speed of 52 meter per minutes with an air flow of 8 bar. The optical fiber cable 200 is blown to the next distance from 1100 meter to 1150 meter in 22.42 minutes with the speed of 58 meter per minutes with an air flow of 9 bar. The optical fiber cable 200 is blown to the next distance from 1150 meter to 1200 meter in 23.36 minutes with the speed of 60 meter per minutes with an air flow of 9 bar.The optical fiber cable 200 is blown to the next distance from 1200 meter to 1250 meter in 24.36 minutes with the speed of 58 meter per minutes with an air flow of 9 bar. The optical fiber cable 200 is blown to the next distance from 1250 meter to 1300 meter in 25.35 minutes with the speed of 55 meter per minutes with an air flow of 9 bar. The optical fiber cable 200 is blown to the next distance from 1300 meter to 1350 meter in 26.40 minutes with the speed of 55 meter per minutes with an air flow of 9 bar. The optical fiber cable 200 is blown to the next distance from 1350 meter to 1400 meter in 27.39 minutes with the speed of 55 meter per minutes with an air flow of 10 bar.The optical fiber cable 200 is blown to the next distance from 1400 meter to 1450 meter in 28.40 minutes with the speed of 53 meter per minutes with an air flow of 10 bar.The optical fiber cable 200 is blown to the next distance from 1450 meter to 1500 meter in 29.47 minutes with the speed of 53 meter per minutes with an air flow of 10 bar. The optical fiber cable 200 is blown to the next distance from 1500 meter to 1550 meter in 30.50 minutes with the speed of 52meter per minutes with an air flow of 11 bar. The optical fiber cable 200 is blown to the next distance from 1550 meter to 1600 meter in 31.55 minutes with the speed of 50 meter per minutes with an air flow of 11 bar. The optical fiber cable 200 is blown to the next distance from 1600 meter to 1650 meter in 33.03 minutes with the speed of 45 meter per minutes with an air flow of11 bar. The optical fiber cable 200 is blown to the next distance from 1650 meter to 1700 meter in 34.17 minutes with the speed of 45 meter per minutes with an air flow of 12 bar. The optical fiber cable 200 is blown to the next distance from 1700 meter to 1750 meter in 35.22 minutes with the speed of 50 meter per minutes with an air flow of 12 bar.The optical fiber cable 200 is blown to the next distance from 1750 meter to 1800 meter in 36.28 minutes with the speed of 46 meter per minutes with an air flow of 12 bar.The optical fiber cable 200 is blown to the next distance from 1800 meter to 1827 meter in 37.05 minutes with the speed of 50 meter per minutes with an air flow of 13 bar.
[0078] The optical fiber cable 200 passed the test. The average speed calculated for blowing the optical fiber cable 200 was 50.97 meter per minute.
[0079] Test Cable 2: 288f mini cable with an average diameter of 10.2mm.
[0080] The second cable for the test includes the mini optical fiber cable. The type of tube used for the mini optical fiber cable is 18/14 mm. The route used for the mini optical fiber cable includes a distance of 1900 meter. The number of fiber in the mini optical fiber cable is 288. The data corresponding to the test results of the mini optical fiber cable includes distance, time, speed and air flow of the blowing operation.
[0081] The mini optical fiber cable is blown to a distance of 50 meter in 1.03 minutes with a speed of 50 meter per minute. The mini optical fiber cable is blown to the next distance from 50 meter to 100 meter in 2.11 minutes with the speed of 44 meter per minutes. The mini optical fiber cable is blown to the next distance from 100 meter to 150 meter in 3.28 minutes with the speed of 38 meter per minutes. The mini optical fiber cable is blown to the next distance from 150 meter to 200 meter in 4.56 minutes with the speed of 37 meter per minutes with an air flow of 5 bar. The mini optical fiber cable is blown to the next distance from 200 meter to 250 meter in 6.21 minutes with the speed of 33 meter per minutes with an air flow of 7 bar. The mini optical fiber cable is blown to the next distance from 250 meter to 300 meter in 7.34 minutes with the speed of 50 meter per minutes with an air flow of 8 bar. The mini optical fiber cable is blown to the next distance from 300 meter to 350 meter in 8.41 minutes with the speed of 44 meter per minutes with an air flow of 8 bar. The mini optical fiber cable is blown to the next distance from 350 meter to 400 meter in 9.58 minutes with the speed of 38 meter per minutes with an air flow of 8 bar. The mini optical fiber cable is blown to the next distance from 400 meter to 450 meter in 11.08 minutes with the speed of 44 meter per minutes with an air flow of 9 bar. The mini optical fiber cable is blown to the next distance from 450 meter to 500 meter in 12.23 minutes with the speed of 38 meter per minutes with an air flow of 9 bar. The mini optical fiber cable is blown to the next distance from 500 meter to 550 meter in 13.47 minutes with the speed of 35 meter per minutes with an air flow of 9 bar. The mini optical fiber cable is blown to the next distance from 550 meter to 600 meter in 14.58 minutes with the speed of 43 meter per minutes with an air flow of 10 bar. The mini optical fiber cable is blown to the next distance from 600 meter to 650 meter in 16.12 minutes with the speed of 40 meter per minutes with an air flow of 10 bar. The mini optical fiber cable is blown to the next distance from 650 meter to 700 meter in 17.26 minutes with the speed of 40 meter per minutes with an air flow of 10 bar. The mini optical fiber cable is blown to the next distance from 700 meter to 750 meter in 18.34 minutes with the speed of 42 meter per minutes with an air flow of 11 bar. The mini optical fiber cable is blown to the next distance from 750 meter to 800 meter in 19.46 minutes with the speed of 42 meter per minutes with an air flow of 11 bar. The mini optical fiber cable is blown to the next distance from 800 meter to 850 meter in 21.02 minutes with the speed of 40 meter per minutes. with an air flow of 11 bar. The mini optical fiber cable is blown to the next distance from 850 meter to 900 meter in 22.21 minutes with the speed of 40 meter per minutes. with an air flow of 11 bar. The mini optical fiber cable is blown to the next distance from 900 meter to 950 meter in 23.36 minutes with the speed of 45 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 950 meter to 1000 meter in 24.52 minutes with the speed of 38 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1000 meter to 1050 meter in 26.12 minutes with the speed of 37 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1050 meter to 1100 meter in 27.36 minutes with the speed of 38 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1100 meter to 1150 meter in 29.00 minutes with the speed of 35 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1150 meter to 1200 meter in 30.27 minutes with the speed of 35 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1200 meter to 1250 meter in 32.00 minutes with the speed of 33 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1250 meter to 1300 meter in 33.35 minutes with the speed of 31 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1300 meter to 1350 meter in 35.12 minutes with the speed of 31 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1350 meter to 1400 meter in 36.53 minutes with the speed of 30 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1400 meter to 1450 meter in 38.34 minutes with the speed of 29 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1450 meter to 1500 meter in 40.22 minutes with the speed of 29 meter per minutes with an air flow of 13bar. The mini optical fiber cable is blown to the next distance from 1500 meter to 1550 meter in 42.12 minutes with the speed of 29 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1550 meter to 1600 meter in 44.03 minutes with the speed of 28 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1600 meter to 1650 meter in 45.57 minutes with the speed of 28 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1650 meter to 1700 meter in 48.03 minutes with the speed of 25 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1700 meter to 1750 meter in 50.24 minutes with the speed of 22 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1750 meter to 1800 meter in 53.00 minutes with the speed of 19 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1800 meter to 1824 meter in 54.31 minutes with the speed of 19 meter per minutes with an air flow of 13 bar.
[0082] The mini optical fiber cable with 288 fibers failed the test. The mini optical fiber cable failed in the test due to the slow speed. The average speed calculated for blowing the mini optical fiber cable was 34.90 meter per minute.
[0083] Test Cable 3: 24f mini cable with an average diameter of 4.3mm.
[0084] The third cable for the test includes the mini optical fiber cable. The type of tube used for the mini optical fiber cable is 10/7 mm. The route used for the mini optical fiber cable includes a distance of 1900 meter. The number of fiber in the mini optical fiber cable is 24. The data corresponding to the test results of the mini optical fiber cable includes distance, time, speed and air flow of the blowing operation.
[0085] The mini optical fiber cable is blown to a distance of 50 meter in 0.56 minutes with a speed of 65 meter per minute. The mini optical fiber cable is blown to the next distance from 50 meter to 100 meter in 1.42 minutes with the speed of 65 meter per minutes. The mini optical fiber cable is blown to the next distance from 100 meter to 150 meter in 2.34 minutes with the speed of 65 meter per minutes. The mini optical fiber cable is blown to the next distance from 150 meter to 200 meter in 3.27 minutes with the speed of 50 meter per minutes with an air flow of 0 bar. The mini optical fiber cable is blown to the next distance from 200 meter to 250 meter in 4.32 minutes with the speed of 60 meter per minutes with an air flow of 1 bar. The mini optical fiber cable is blown to the next distance from 250 meter to 300 meter in 5.27 minutes with the speed of 60 meter per minutes with an air flow of 1 bar. The mini optical fiber cable is blown to the next distance from 300 meter to 350 meter in 6.23 minutes with the speed of 50 meter per minutes with an air flow of 2 bar. The mini optical fiber cable is blown to the next distance from 350 meter to 400 meter in 7.23 minutes with the speed of 60 meter per minutes with an air flow of 3 bar. The mini optical fiber cable is blown to the next distance from 400 meter to 450 meter in 8.27 minutes with the speed of 50 meter per minutes with an air flow of 3 bar. The mini optical fiber cable is blown to the next distance from 450 meter to 500 meter in 9.26 minutes with the speed of 50 meter per minutes with an air flow of 4 bar. The mini optical fiber cable is blown to the next distance from 500 meter to 550 meter in 10.31 minutes with the speed of 50 meter per minutes with an air flow of 5 bar. The mini optical fiber cable is blown to the next distance from 550 meter to 600 meter in 11.36 minutes with the speed of 50 meter per minutes with an air flow of 5 bar. The mini optical fiber cable is blown to the next distance from 600 meter to 650 meter in 12.36 minutes with the speed of 50 meter per minutes with an air flow of 6 bar. The mini optical fiber cable is blown to the next distance from 650 meter to 700 meter in 13.47 minutes with the speed of 50 meter per minutes with an air flow of 7 bar. The mini optical fiber cable is blown to the next distance from 700 meter to 750 meter in 14.52 minutes with the speed of 45 meter per minutes with an air flow of 7 bar. The mini optical fiber cable is blown to the next distance from 750 meter to 800 meter in 16.02 minutes with the speed of 40 meter per minutes with an air flow of 7 bar. The mini optical fiber cable is blown to the next distance from 800 meter to 850 meter in 17.02 minutes with the speed of 55 meter per minutes. with an air flow of 8 bar. The mini optical fiber cable is blown to the next distance from 850 meter to 900 meter in 18.05 minutes with the speed of 50 meter per minutes. with an air flow of 8 bar. The mini optical fiber cable is blown to the next distance from 900 meter to 950 meter in 19.06 minutes with the speed of 50 meter per minutes with an air flow of 9 bar. The mini optical fiber cable is blown to the next distance from 950 meter to 1000 meter in 20.12 minutes with the speed of 60 meter per minutes with an air flow of 10 bar. The mini optical fiber cable is blown to the next distance from 1000 meter to 1050 meter in 21.13 minutes with the speed of 45 meter per minutes with an air flow of 10 bar. The mini optical fiber cable is blown to the next distance from 1050 meter to 1100 meter in 22.15 minutes with the speed of 60 meter per minutes with an air flow of 11 bar. The mini optical fiber cable is blown to the next distance from 1100 meter to 1150 meter in 23.07 minutes with the speed of 52 meter per minutes with an air flow of 11 bar. The mini optical fiber cable is blown to the next distance from 1150 meter to 1200 meter in 24.14 minutes with the speed of 45 meter per minutes with an air flow of 11 bar. The mini optical fiber cable is blown to the next distance from 1200 meter to 1250 meter in 25.21 minutes with the speed of 50 meter per minutes with an air flow of 12 bar. The mini optical fiber cable is blown to the next distance from 1250 meter to 1300 meter in 26.32 minutes with the speed of 53 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1300 meter to 1350 meter in 27.13 minutes with the speed of 50 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1350 meter to 1400 meter in 28.47 minutes with the speed of 42 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1400 meter to 1450 meter in 30.07 minutes with the speed of 28 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1450 meter to 1500 meter in 31.40 minutes with the speed of 33 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1500 meter to 1550 meter in 33.20 minutes with the speed of 28 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1550 meter to 1600 meter in 35.19 minutes with the speed of 25 meter per minutes with an air flow of 13 bar. The mini optical fiber cable is blown to the next distance from 1600 meter to 1632 meter in 36.48 minutes with the speed of 25 meter per minutes with an air flow of 13bar.
[0086] The mini optical fiber cable with 24 fibers passed the test. The average speed calculated for blowing the mini optical fiber cable was 51.16 meter per minute.
[0087] It may be noted in reference with the above mentioned embodiments, performance and test results of 288 fiber optical fiber cable 200 (Fig. 2) (included above as part of table - 1, table -2 and table -3 embodiments) that the 192 fiber optical fiber cable 100 (Fig. 1) shows similar blowing performance results as 288 fiber optical fiber cable 200. The blowing performance of 192 fiber optical fiber cable 100 is similarly optimized as 288 fiber optical fiber cable 200. Further, those skilled in the art would appreciate that the 192 fiber optical fiber cable 100 (Fig. 1) is similarly optimized as 288 fiber optical fiber cable 200 (Fig. 2) as both the optical fiber cables (100, 200) use similar dual layer buffer tubes.
[0088] Further, it may be noted that in FIG. 1, the optical fiber cable 100 includes eight buffer tubes; and in other embodiment, the optical fiber cable 200 includes twenty four buffer tubes; however, those skilled in the art would appreciate that more or less number of buffer tubes are included in the optical fiber cable 100.
[0089] The micro optical fiber cable has numerous advantages over the prior art. The micro optical fiber cable is easy to installer in small ducts. The optical fiber cable includes a dual layer of buffer tubes with low thickness of polycarbonate and polybutylene terephthalate. The dual layer buffer tubes can be used for other configurations with 250 micron optical fibers and 200 micron optical fibers to reduce cable diameter which in turn improves the blowing performance. . The small diameter of optical fiber cable enables easier installation of the micro optical fiber cable in the small ducts. Further, the small diameter increases the blowing performance of the micro optical fiber cable.
[0090] The foregoing descriptions of pre-defined embodiments 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 embodiments 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 embodiments 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 f
Claims:Claims
What is claimed is:
1. An optical fiber cable (100) comprising:
a central strength member (102) lying substantially along a longitudinal axis of the optical fiber cable (100), wherein the central strength (102) member is made offibre reinforced plastic, wherein the central strength member (102) has a diameter of about 3.0 mm;
a first layer (104) wrapped helically around the central strength member, wherein the first layer is a plurality of water swellable yarns (104a-104c);
a plurality of buffer tubes (106) stranded helically around the first layer (104),
wherein each of the plurality of buffer tube (106) has a first diameter of about1.55 mm ± 0.05 mm, wherein each of the plurality of buffer tube (106) has a second diameter of about 1.85 mm ±0.05 mm,
wherein each of the plurality of buffer tube (106) is made of a combination of two sub layers having different material, wherein each of the plurality of buffer tube (106) has a first sub layer and a second sub layer, wherein the first sub layer is made of polycarbonate,
wherein the first sub layer has a thickness of about 75 microns ± 10 microns, wherein the first sub layer has a density of about1.2 gm/cm3, wherein the first sub layer is the inner sub layer of the buffer tube,
wherein the second sub layer is made of polybutylene terephthalate, wherein the second sub layer has a thickness of about75 microns ± 10 microns, wherein the second sub layer has a density of about 1.31 gm/cm3, wherein the second sub layer is the outer sub layer of the buffer tube,

wherein each of the plurality of buffer tubes (106) encloses a plurality of optical fibers (108), wherein the plurality of buffer tubes (106) being eight, wherein the plurality of optical fibers (108) in each buffer tube being twenty four, wherein each of the plurality of optical fibers (108) has a diameter of about 250 microns;
a second layer (110), wherein the second layer (110) cross helically surrounds a core of the optical fiber cable (100), wherein the second layer (110) is formed of a pair of binder yarns, wherein the pair of binder yarn comprising:
a first binder yarn, wherein the first binder yarn being wrapped helically in clockwise direction;
a second binder yarn, wherein the second binder yarn being wrapped helically in anti-clockwise direction;
a third layer (114) wrapped helically around the core of the optical fiber cable (100), wherein the third layer (114) is a plurality of water swellable yarn;
a fourth layer (116) surrounding the third layer (114), wherein the fourth layer (116) is made of high density polyethylene, wherein the fourth layer (116) has a thickness in the range of about 0.4 mm to 0.6 mm, wherein the fourth layer (116) has a density in the range of about 0.90 gm/cm3 to 0.96 gm/cm3; and
wherein the optical fiber cable (100) has a diameter of about 7.7 mm ± 0.2 mm.
2. The optical fiber cable (100) as recited in claim 1, wherein the central strength member (102) is made of a solid pultrusion type fiber reinforced plastic wherein the central strength member (102) optimizes the stiffness and blowing performance of optical fiber cable (100).

3. The optical fiber cable (100) as recited in claim 1, wherein the central strength member (102) is being coated with a polyethylene layer, wherein the central strength member (102) is being coated to accommodate plurality of buffer tubes (106).
4. The optical fiber cable (100) as recited in claim 1, wherein the first binder yarn and second binder yarn is an aramid type binder yarn.
5. The optical fiber cable (100) as recited in claim 1, wherein the binder yarn is water blocking type aramid yarn.
6. The optical fiber cable (100) as recited in claim 1, wherein the plurality of ripcord (116a -116b) are high strength water blocking type yarns.
7. The optical fiber cable (100) as recited in claim 1, wherein the optical fiber cable (100) is blown into a duct having an inner diameter of 10mm and outer diameter of 14 mm.
8. The optical fiber cable as claimed in claim 1, wherein the plurality of ripcords (116a-116b) being positioned between the fourth layer (114) and along with the third layer (112) in linear manner.
9. The optical fiber cable (100) as recited in claim 1, wherein the optical fiber cable (100) when blown into duct having an inner diameter of 10 mm and outer diameter of 14 mm has a fill factor in a range of about 54% to 64%.
10. The optical fiber cable (100) as recited in claim 1, wherein the buffer tube has a packing factor in a range of about 75% to 92%.