Dense cable with improved jetting properties

Abstract

An exemplary optical fiber cable includes a cable jacket formed of a first polymer composition, and a cable core that includes a plurality of optical fibers. The cable core can have any of various constructions, and the optical fibers can be disposed in various ways such as, but not limited to, loose fibers in buffer tubes (i.e., loose tube construction), planar optical fiber ribbons, or rollable optical fiber ribbons (e.g., intermittently-bonded optical fiber ribbons). To aid in jetting performance, the optical fiber cable further includes a plurality of high-modulus polymeric filaments that are embedded in and coextruded with the cable jacket.

Description

Attorney Docket No.: HI24-052PCTTitle: DENSE CABLE WITH IMPROVED JETTING PROPERTIESRELATED APPLICATIONS

[0001] This application claims priority to United States Provisional Patent Application No. 63 / 724,985, filed on November 26, 2024, and entitled “DENSE CABLE WITH IMPROVED JETTING PROPERTIES,” the entirety of which is incorporated herein by reference.BACKGROUND

[0002] Optical fiber cables are now commonly installed by “jetting” or “blowing” procedures. In these installation methods, an optical fiber cable is installed into a duct (which may be buried underground or routed through the interior of a building) by a stream of air that is jetted, or blown, through the duct. This stream of air effectively pushes the cable through the duct along a desired installation route, thereby allowing an installer to easily and quickly route a cable between two points in an installation network.

[0003] Optical fiber cables for telecommunications are designed to meet various requirements that encompass desirable performance characteristics. Among these are robustness against environmental conditions, high optical fiber density, and low signal attenuation. The design of any particular optical fiber cable represents a tradeoff as among applicable requirements for a particular application for which the optical fiber cable was designed.

[0004] For many cable installations, it is desirable that a cable be jetted for long distances. However, the determinants of jetting distance are not well understood. While the path of a duct through which a cable is to be jetted is a significant factor, different cables can exhibit substantially different jetting distances within a same duct path.SUMMARY OF THE DISCLOSURE

[0005] The following is a brief summary of subject matter that is described in greater detail herein. This summary is not intended to be limiting as to the scope of the claims.

[0006] Various technologies pertaining to an optical fiber cable that has a high optical fiber density, low signal attenuation, and long jetting distance are described herein. While jetting of optical fiber cables is now common practice, the distance for which an optical fiber cable can be jetted through a duct is often less than is desirable or intended. Applicant has identified that bending stiffness of an optical fiber cable is a significant contributor to jettingAttorney Docket No.: HI24-052PCT performance. However, conventional means for increasing the bending stiffness of an optical fiber cable, such as including large central fiber-reinforced plastic (FRP) rods around which cable core elements are stranded, tend to increase the cable diameter needed to achieve a low- attenuation cable. Thus, conventional means for improving bending stiffness are insufficient to yield a high-density, low-attenuation optical fiber cable that also exhibits good jetting performance.

[0007] The inventors of the present application have determined that an optical fiber cable can be made to have a high fiber density while maintaining sufficient bending stiffness for good jetting performance by inclusion of co-extruded, high-modulus polymeric filaments embedded in the cable jacket.

[0008] An exemplary optical fiber cable includes a cable jacket formed of a first polymer composition, and a cable core that includes a plurality of optical fibers. The cable core can have any of various constructions, and the optical fibers can be disposed in various ways such as, but not limited to, loose fibers in buffer tubes (i.e., loose tube construction), planar optical fiber ribbons, or rollable optical fiber ribbons (e.g., intermittently-bonded optical fiber ribbons). To aid in jetting performance, the optical fiber cable further includes a plurality of high-modulus polymeric filaments that are embedded in and coextruded with the cable jacket.

[0009] The above summary presents a simplified summary in order to provide a basic understanding of some aspects of the systems and / or methods discussed herein. This summary is not an extensive overview of the systems and / or methods discussed herein. It is not intended to identify key or critical elements or to delineate the scope of such systems and / or methods. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiments, and together with the description serve to explain principles and operation of the various embodiments.

[0011] FIG. 1 depicts a cross-sectional view of an exemplary optical fiber cable;

[0012] FIG. 2 depicts an exemplary jetting system;Attorney Docket No.: HI24-052PCT

[0013] FIG. 3 is a photograph of an exemplary optical fiber cable constructed in similar manner to FIG. 1 ;

[0014] FIG. 4 is a chart illustrating measurements of bending stiffness of certain experimental cables at different temperatures.DETAILED DESCRIPTION

[0015] Various technologies pertaining to a high-density optical fiber cable with good jetting performance are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect(s) may be practiced without these specific details. In other instances, well-known structures and devices may be shown in block diagram form in order to facilitate describing one or more aspects. Further, it is to be understood that functionality that is described as being carried out by certain system components may be performed by multiple components. Similarly, for instance, a component may be configured to perform functionality that is described as being carried out by multiple components.

[0016] Moreover, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or”. That is, unless specified otherwise, or clear from the context, the phrase “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from the context to be directed to a singular form. Additionally, as used herein, the term “exemplary” is intended to mean serving as an illustration or example of something, and is not intended to indicate a preference.

[0017] Referring now to Fig. 1, an exemplary optical fiber cable 100 is illustrated. The optical fiber cable 100 comprises a cable jacket 102 that has an outer surface 104 and an inner surface 106. The outer surface 104 can be an outermost surface of the optical fiber cable 100. The inner surface 106 encloses a region of space referred to herein as a bore 108 of the optical fiber cable 100.

[0018] In one or more embodiments, the cable jacket 102 has a thickness between the outer surface 104 and the inner surface 106 in a range from 0.5 mm to 1 mm. In particularAttorney Docket No.: HI24-052PCT embodiments, the cable jacket 102 has a thickness that is from 8% to 10% of the outer diameter of the optical fiber cable 100 (as measured at the outer surface 104 of the cable jacket 102). In one or more embodiments, the cable jacket 102 is made from a polyethylene material (such as high density polyethylene (HDPE)), a low-smoke zero halogen (LSZH) polymer, a filled polyethylene, a flame retardant (FR) polymer, or a urethane polymer, amongst other possibilities.

[0019] The optical fiber cable 100 further includes a cable core 110 that is disposed within the bore 108. The cable core 110 includes a plurality of optical fibers 112. In general, the cable core 110 is configured to have an optical fiber density of at least 8 fibers / mm2, at least 8.5 fibers / mm2, at least 9 fibers / mm2, at least 9.5 fibers / mm2, at least 10 fibers / mm2, at least 10.5 fibers / mm2, at least 11 fibers / mm2, at least 11.5 fibers / mm2, or at least 12 fibers / mm2. In one or more embodiments, the fiber density may be up to 17 fibers / mm2. As used herein, the fiber density of an optical fiber cable refers to a number of optical fibers disposed in the bore of the optical fiber cable divided by a total cross-sectional area of the optical fiber cable looking into an end of the optical fiber cable (i.e., measured from its outside diameter). Whereas other measurements of density consider a number of fibers within a cross-sectional area of the cable core (i.e., excluding the area of the jacket), a fiber density based on the total cross-sectional area more accurately indicates the ability of an optical fiber cable to carry a desired number of optical fibers within the limited space available in a duct (e.g., into which the cable is to be jetted).

[0020] Further, in one or more embodiments, the optical fiber cable 100 comprises more than or equal to 144 optical fibers, more than or equal to 288 optical fibers, more than or equal to 432 optical fibers, more than or equal to 576 optical fibers, more than or equal to 864 optical fiber, more than or equal to 864 optical fibers, more than or equal to 1152 optical fibers, more than or equal to 1728 optical fibers, more than or equal to 3456 optical fibers or more than equal to 6912 optical fibers. Further, in one or more embodiments, the optical fiber cable 100 comprises at least 288 optical fibers.

[0021] Further, in one or more embodiments, the outer diameter of the optical fiber cable 100 as measured at the outer surface 104 is 30 mm or less, 25 mm or less, 20 mm or less, 18 mm or less, 16 mm or less, 14 mm or less, 12 mm or less, 10 mm or less, 8 mm or less, 7 mm or less, 6 mm or less, 5 mm or less, or 4 mm or less. Further, in one or more embodiments, the outer diameter of the optical fiber cable 100 as measured from the outer surface 104 is at least 3 mm.Attorney Docket No.: HI24-052PCT

[0022] As shown in Fig. 1, the cable core 110 comprises a plurality of subunits 114, wherein each of the subunits 114 comprises a polymeric binder 116 within which are disposed a plurality of the optical fibers 112. In exemplary embodiments, polymeric binder 116 can be a thin polymeric film having a wall thickness of 50 microns or less, more particularly 40 microns or less, or still more particularly 30 microns or less. In one or more embodiments, the wall thickness of the polymeric binder 116 is from 10 microns to 100 microns, in particular from 25 microns to 75 microns, and most particularly from 35 microns to 50 microns. In other embodiments, the polymeric binder 116 can be replaced by binder threads or yarns. The optical fibers 112 disposed within each of the subunits 114 can be loose optical fibers or can be ribbonized into one or more rollable optical fiber ribbons (e.g., intermittently-bonded optical fiber ribbons).

[0023] It is to be appreciated that while the subunits 114 are shown in Fig. 1 as having a circular outer profile, the polymeric binder 116 of each subunit is not rigid, and may be deformed. Thus, the subunits 114 are able to take different shapes and the fibers 112 are able to shift to low-stress positions as the cable 100 is bent and subject to other stresses, thereby permitting a free space within the bore 108 to be reduced relative to a conventional loose-tube construction with rigid buffer tubes.

[0024] In one or more embodiments, the optical fiber cable 100 has a cumulative fiber filling coefficient of at least 50%, at least 60%, at least 65%, or at least 70%. In one or more embodiments, the optical fiber cable 100 has a cumulative fiber filling coefficient of up to 85%. As used herein, the term “cumulative fiber filling coefficient” of an optical-fiber cable (e.g., cable 100)refers to the ratio of the sum of the cross-sectional areas of all of the optical fibers (e.g., optical fibers 112) within the optical-fiber cable versus the inner cross-sectional area of the optical -fiber cable (i.e., defined by the inner surface (e.g., inner surface 106) of the cable jacket (e.g., cable jacket 102) or inner surface of a binder film surrounding the subunits (e.g., subunits 114), if included). For the purposes of evaluating the cumulative fiber filling coefficient, the cross-sectional area of each optical fiber in a cable is determined based on a diameter fo the optical fiber at an outermost surface of the optical fiber (for instance, at an outer surface of a secondary coating or an ink layer of an optical fiber).

[0025] In one or more embodiments, the optical fiber cable 100 comprises a free space of at most 50%, at most 42.5%, at most 30%, or at most 25%. In one or more embodiments, the free space of the optical fiber cable 100 is at least 15%. As used herein, the free space is the inverse of cumulative fiber filling coefficient (i.e., 100% - cumulative fiber fillingAttorney Docket No.: HI24-052PCT coefficient).

[0026] The optical fibers 112 can be selected to have a low bend sensitivity, thereby contributing to a high fiber density of the cable 100. In exemplary embodiments, the optical fibers 112 are selected to have a bend loss at 1550 nm of less than 0.5 dB / turn for a mandrel diameter of 15 mm, less than 0.1 dB / turn for a mandrel diameter of 20 mm, and / or less than 0.003 dB / turn for a mandrel diameter of 30 mm. In exemplary embodiments, the optical fibers 112 have a mode field diameter at 1310 nm of between 8.2 microns and 9.5 microns, and in particular a mode field diameter at 1310 nm of at least 9 microns. In further embodiments, the optical fibers 112 have a cabled cutoff of less than 1260 nm and a zero-dispersion wavelength between 1300 nm and 1324 nm.

[0027] The optical fiber cable 100 is configured to meet a stringent attenuation requirement in low-temperature environments. In particular, each of the optical fibers 112 in the cable exhibits an attenuation increase of less than 0.15 dB / km at 1550 nm during a second excursion to -40°C during a temperature cycling test as measured according to IEC 60794-5- 10.

[0028] In the embodiment depicted in Fig. 1, the optical fiber cable 100 is shown to include 12 subunits 114, each with 12 optical fibers 112 disposed therein. However, it is to be understood that a number of the subunits 114 and a number of optical fibers within each subunit 114 can be varied consistent with the scope of the present disclosure. When a number of the optical fibers 112 in each of the subunits 24 is greater than 12, a subset of the optical fibers 112 within each of the subunits 114 can be ringmarked to maintain fiber identifiability. In other embodiments, the optical fibers 112 of the subunits 114 can be disposed in rollable optical fiber ribbons to maintain fiber organization and identifiability. In such embodiments, an identifier can be printed on each of the ribbons for purposes of identification.

[0029] In various embodiments, the subunits 114 can be stranded in a helical or S-Z stranding pattern. In such embodiments, the subunits 114 can be wrapped with a binder (not shown) to maintain the stranding of the subunits 114. Such a binder can be binder threads or yarns, or can be a thin-film polymer binder.

[0030] The cable core 110 can further include various elements commonly found in optical fiber cables such as, but not limited to, binders (e.g., as discussed above), waterblocking tapes or yarns, tensile strength yarns, or armor layers. However, apart from the filaments 118, the cable 100 does not include strength elements embedded in the jacket 102,Attorney Docket No.: HI24-052PCT and does not include a central strength member (such as an FRP rod) within the cable core 110.

[0031] As noted above, Applicant has observed that cable stiffness is a parameter that tends to affect the achievable jetting distance of an optical fiber cable. In particular, the inventors have determined that a cable stiffness that is too low is a limiting factor to the achievable jetting distance for many high-density cable designs. However, conventional means of increasing the stiffness of an optical fiber cable, such as large FRP central strength elements, tend to increase the necessary diameter of an optical fiber cable. Thus, conventional means of increasing cable stiffness tend to yield lower-density cables.

[0032] Accordingly, the optical fiber cable 100 includes a plurality of high-modulus, polymeric filaments 118 that are co-extruded with and embedded in the cable jacket 102. Still further, the optical fiber cable 100 can be configured to have no strength elements disposed within the central bore 108 other than non-rigid tensile yams.

[0033] In general, the cable jacket 102 is formed of a first polymer phase and each of the filaments 118 is formed of a second polymer phase. In exemplary embodiments, the second polymer phase of the filaments 118 has a Young’s modulus that is greater than a Young’s modulus of the first polymer phase of the cable jacket 102. Accordingly, the filaments 118 provide a greater stiffness to the cable jacket 102 than the jacket 102 would otherwise exhibit absent the filaments 118.

[0034] The filaments 118 are extruded longitudinal elements and thus extend along a length of the optical fiber cable 100 and occupy some fraction of the cross-sectional area of the cable jacket 102. Thus, the filaments 118 are dissimilar to chopped fibers or other fillers that are sometimes used to stiffen other resins (e.g., in the case of FRP strength elements). In exemplary embodiments, the filaments 118 are each characterized by a maximum width that ranges between 0.05 mm to 2 mm, between 0.2 mm to 1.8 mm, or more particularly between 0.5 mm to 1.75 mm. In the depiction of Fig. 1, the filaments 118 are shown as being substantially circular. However, it is to be understood that the filaments 118 can have other shapes such as, but not limited to, teardrops, ellipses, etc. Furthermore, in some embodiments the cable 100 can have a web (not shown) of the same material used to form the filaments 118 extending between one or more of the filaments 118.

[0035] In some embodiments, the first polymer phase used to form the cable jacket 102 comprises polyethylene, whereas the second polymer phase used to form the filaments 118Attorney Docket No.: HI24-052PCT comprises a high-modulus polymer such as polycarbonate, a liquid crystal polymer, or combinations thereof. In some embodiments, the elastic modulus of the high-modulus polymer is greater than 2 GPa. In further embodiments, the elastic modulus of the high modulus polymer is greater than 5 GPa. In still further embodiments, the elastic modulus of the high modulus polymer is greater than 10 GPa.

[0036] Applicant’ s experimentation has shown that an adhesion promoter improves the ability of the filaments 118 to stiffen the cable jacket 102. Accordingly, to control the interaction between the first phase of the cable jacket 102 and the second phase of the filaments 118, copolymeric or polymeric coupling agents are added into either or both of the polymer phases. Materials to be added to the polymer phases are chosen to be miscible or partially miscible on the respective added polymeric phase. By adding these coupling agents, an interfacial tie layer is formed between the cable jacket 102 and the filaments 118 by chemical or physical bonds. Exemplary coupling agent additives to the polymer phases of the jacket 102 and filaments 118 include grafted polymers or terpolymers with functional groups like maleic acid anhydrite, silanes, epoxies, acrylates, amines, hydroxyls, melamines, zirconates, titanates, polyols, esters or ionomers of these with a functionality in between 0.5 and 25 wt%. In embodiments wherein the coupling polymers are included in the jacket 102, backbones of the coupling polymers can be based on high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear LDPE (LLDPE) polypropylene, ethylene-vinyl acetate, ethylene methyl acrylate copolymer, ethylene butyl acrylate copolymer, ethylene ethyl acrylate copolymer, or mixtures thereof. In embodiments wherein the coupling polymers are included in the filaments 118, backbones of the coupling polymers can be based on a same material used to form the filaments 118. Generally, an amount of the functional coupling agents added depends on the degree of functionality, and therefore can range from 1 wt% to 25 wt% in either or both of the first polymer phase of the jacket 102 or the second polymer phase of the filaments 118.

[0037] A number and size of the filaments 118 is selected based upon a desired bending stiffness of the cable 100. The number and size of the filaments 118 can be further based upon a Young’s modulus of the filaments 118. Generally, all else being equal, the higher the Young’s modulus of the filaments 118, the fewer of the filaments 118 that are necessary (or the smaller the necessary size of the filaments 118). In exemplary embodiments, the filaments 118 range from 5 wt% of the cable jacket 102 and filaments 118 combined up to 80 wt% of the cable jacket 102 and filaments 118 combined.Attorney Docket No.: HI24-052PCT

[0038] Applicant’ s experiments have indicated that in addition to affecting the possible jetting distance within a duct, the bending stiffness, or flexural rigidity, of a cable also affects the robustness of the cable to damage by a jetting machine during sudden stops of the cable in the duct. Referring now to Fig. 2, a schematic diagram of an exemplary jetting system 200 is illustrated. The system includes a cable reel 202 on which a cable 204 is wound. The system 200 further includes a jetting machine 206 and a duct 208 into which the cable 204 is to be jetted. The jetting machine 206 comprises a capstan 210, a cable guide 212, and a high- pressure air inlet 214. The capstan 210 pulls the cable 204 from the reel 202 and pushes the cable 204 toward the cable guide 212. The cable guide 212 receives the cable and directs the cable 204 (being pushed by the capstan 210) into the duct 208. The high-pressure air inlet 214 is coupled to the duct 208 and blows air at high-pressure through the duct 208 and past the cable 204, further pushing the cable 204 through the duct 208.

[0039] In some cases, the cable 204 can become temporarily stuck in the duct 208 or can reach a region of the duct 208 that is difficult to pass, thereby causing rapid deceleration of the cable 204 in the duct 208. During such events, the cable 204 is nevertheless subjected to a pushing force from the capstan 210 that can cause the cable 204 to buckle and create a “bird’s nest,” potentially causing substantial damage to the cable 204.

[0040] The inventors have determined that the susceptibility of the cable 204 to such buckling is based upon the flexural rigidity of the cable 204. In particular, the inventors have determined that a flexural rigidity of the cable 204 should be designed according to the following relation:

[0041] El > F(0.65L)2 / n2Eq. 1

[0042] where El is the flexural rigidity of the cable 204, F is the maximum pushing force of the capstan 210, and L is the maximum unsupported length of the cable 204 between the capstan 210 and the entry to the duct 208 (e.g., a distance between the cable guide 212 and the duct 208 or a distance between the capstan 210 and the cable guide 212). Applicant has determined that, according to Eq. 1, a flexural rigidity of the cable 100 should be greater than or equal to 11,500 N*mm2to avoid a “bird’s nest” cable failure for a typical jetting installation system.

[0043] Accordingly, in exemplary embodiments, the cable jacket 102 and the filaments 118 are configured such that the cable 100 has a flexural rigidity El that satisfies Eq. 1 for a desired duct installation when the cable 100 is subjected to a temperature of 40°C, or moreAttorney Docket No.: HI24-052PCT particularly 55°C, or still more particularly 70°C. With greater specificity, the cable jacket 102 and the filaments 118 are configured such that the cable 100 has a flexural rigidity A / that is greater than or equal to 11,500 N*mm2when subjected to temperatures of 40°C, or more particularly 55°C, or still more particularly 70°C.

[0044] Applicant has observed that in some simulations of jetting performance, jetting performance is seen to increase sharply for cables until a cable bending stiffness of 0.1 N*m2is reached, after which jetting performance increases more slowly with increasing stiffness. Further leveling off appears to occur successively at bending stiffnesses of about 0.2 N*m2and 0.3 N*m2. Accordingly, in various embodiments, the cable jacket 102 and the filaments 118 are configured such that the cable 100 has a bending stiffness of greater than or equal to 0.1 N*m2, greater than or equal to 0.2 N*m2, or greater than or equal to 0.3 N*m2.

[0045] EXPERIMENTAL EXAMPLES

[0046] Fig. 3 is a photograph of an example optical fiber cable 100 prepared according to the present disclosure. As can be seen in Fig. 3, the cable 100 includes a cable jacket 102 and filaments 118 disposed in the cable jacket 102. The example cable shown in Fig. 3 included a high-density polyethylene (HDPE) jacket 102 with filaments 118 formed of a liquid crystal polymer. Further, the cable 100 included the optical fibers 112 disposed within polymeric binders 116. The bending stiffness / flexural rigidity of the exemplary cable 100 shown in Fig. 3 was tested according to a 3-point bending test at temperatures of 20°C, 40°C, and 70°C. Results of the test are recorded in Fig. 4. As can be seen in Fig. 4, the bending stiffness of the exemplary cable shown in Fig. 3 exceeds 11,500 N*mm2at a temperature of 70°C, and far exceeds that threshold at lower temperatures. By contrast, and as shown in Fig. 4, a substantially identical cable that included the same HDPE jacket but did not include the filaments 118 exhibited a substantially lower bending stiffness, and did not exceed the 11,500 N*mm2bending stiffness threshold needed to avoid a “bird’s nest” failure at 20°C much less 70°C.

[0047] What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable modification or alteration of the above systems, devices, or methodologies for purposes of describing the aforementioned aspects, but one of ordinary skill in the art can recognize that many further modifications and permutations of various aspects are possible. Accordingly, the described aspects are intended to embrace all such alterations, modifications, and variations that fallAttorney Docket No.: HI24-052PCT within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.

Claims

Attorney Docket No.: HI24-052PCTCLAIMSWhat is claimed is:

1. An optical fiber cable, comprising: a cable jacket formed of a first composition, wherein the cable jacket defines a bore of the optical fiber cable; a plurality of filaments formed of a second composition and co-extruded with the cable jacket such that the plurality of filaments are embedded in the cable jacket; and a cable core that includes at least one optical fiber and that is disposed in the bore defined by the cable jacket; wherein the optical fiber cable has a flexural rigidity of at least 11,500 N*mm2at 70°C.

2. The optical fiber cable of claim 1, wherein the second composition comprises a liquid crystal polymer.

3. The optical fiber cable of claim 1, wherein the second composition comprises polycarbonate.

4. The optical fiber cable of claim 1, wherein the optical fiber cable does not comprise strength members embedded in the cable jacket other than the plurality of filaments.

5. The optical fiber cable of claim 1, wherein the optical fiber cable does not comprise a central strength element disposed in the bore.

6. The optical fiber cable of claim 1, wherein the optical fiber cable has a fiber density greater than 6 fibers / mm2.

7. The optical fiber cable of claim 1, wherein the optical fiber cable comprises between 432 optical fibers and 6912 optical fibers.

8. The optical fiber cable of claim 1, wherein the at least one optical fiber has an outer diameter of less than 210 microns.Attorney Docket No.: HI24-052PCT9. The optical fiber cable of claim 1, wherein the at least one optical fiber exhibits an attenuation increase of less than 0.15 dB / km at 1550 nm at -30 °C as measured according to IEC 60794-5-10.

10. The optical fiber cable of claim 1, wherein the modulus of plurality of filaments is greater than 2 GPa.

11. The optical fiber cable of claim 1, wherein the plurality of fibers are surrounded by a membrane of thickness less than 150 microns.

12. An optical fiber cable, comprising: a cable jacket formed of a first material; a plurality of filaments coextruded with and embedded in the cable jacket and formed of a second material that has a higher Young’s modulus than the first material; a cable core disposed within the cable jacket, the cable core comprising at least one optical fiber.

13. The optical fiber cable of claim 12, wherein a bending stiffness of the optical fiber cable is at least 11,500 N*mm2at 70°C.

14. The optical fiber cable of claim 12, wherein the optical fiber cable has a fiber density of greater than 6 fibers / mm2.

15. The optical fiber cable of claim 12, wherein the optical fiber cable comprises between 288 optical fibers and 6912 optical fibers.

16. The optical fiber cable of claim 12, wherein the optical fiber cable includes a plurality of optical fibers each having an outer diameter of less than 210 microns.

17. The optical fiber cable of claim 12, wherein the at least one optical fiber exhibits an attenuation increase of less than 0.15 dB / km at 1550 nm at -30 °C as measured according to IEC 60794-5-10.Attorney Docket No.: HI24-052PCT18. The optical fiber cable of claim 12, wherein the modulus of plurality of filaments is greater than 2 GPa.

19. The optical fiber cable of claim 12, wherein the plurality of fibers are surrounded by a membrane of thickness less than 150 microns.

20. A jetting installation system, comprising: an optical fiber cable; a cable reel having the optical fiber cable disposed thereon; a duct; a jetting machine that is configured to pull the optical fiber cable from the cable reel and to push the optical fiber cable into the duct; wherein a bending stiffness, El, of the optical fiber cable satisfies the inequality:El > F(0.65L)2 / n2where F is a maximum pushing force of the jetting machine, and L is a maximum unsupported length of the optical fiber cable between the jetting machine and the duct.

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