WO2020073109A1

WO2020073109A1 - System for distributing power and communication signals in optical fibre access networks

Info

Publication number: WO2020073109A1
Application number: PCT/BR2019/050438
Authority: WO
Inventors: Luiz Henrique Zimmermann FELCHNER; Renato Flávio CRUZ; Rafael Goes BARRETO; Rodrigo Arenales ARANTES; Michael Kulczynskyj; Anderson Marcelo STANCYK; Elton PELOIA; Eduardo SERPE
Original assignee: Furukawa Electric Latam S.A.
Priority date: 2018-10-08
Filing date: 2019-10-08
Publication date: 2020-04-16
Also published as: GB202106410D0; GB2592532A; CL2019000674A1; CO2021004969A2; PE20200655A1; DE112019005036T5; ES2869464A2; ES2869464R1

Abstract

The present invention relates to a system for distributing power in optical fibre access networks using optical boxes (10), including an optical box bus containing at least one optical splitter box (10) connected in sequence and terminating in a terminal box (12). The at least one optical splitter box (10) receives a splitter cable (CD) formed by a single optical fibre, providing a given optical input power (A'), said optical splitter box (10) having an input splitter (DE) to effect the unbalanced splitting of the optical input power (A') received in the optical box (10) of the bus into two parts. A first part of the optical input power (A') is conveyed to an output splitter (DS). The output splitter (DS) splits the first part of the optical power into optical powers that are selectively transferred to respective user terminal optical cables (CT). A second part of the optical input power (A') is conveyed to a subsequent optical box (10, 12) of the bus over a continuation cable (CC) and so on until said last optical termination box (12) is reached, where the optical input power is fully available to the user terminal optical cables (CT).

Description

"COMMUNICATION AND POWER SIGNAL DISTRIBUTION SYSTEM IN OPTICAL FIBER ACCESS NETWORKS"

FIELD OF THE INVENTION

[001] The present invention refers to a system for distributing communication and power signals in optical fiber access networks, using optical junction and / or termination boxes, generally hermetic and of the type that has a housing provided with a entrance opening, to receive an optical distribution or bypass cable, by connectorization or fusion, containing one or more optical fibers, and a plurality of exit openings, generally provided in a cap, sealed or removable, and through outlet openings are provided, by connectorization or by fusion, the connection of a respective fiber division of the optical distribution cable or a respective separate optical fiber / derived from the latter, with a respective user terminal optical cable ("drop" cable) ), projecting the said optical box.

PREVIOUS TECHNIQUE

[002] Fiber optics are increasingly used for a variety of broadband applications, including voice, video and data transmissions. As a result of the growing demand for broadband communications, providers and / or operators of telecommunication and cable services are expanding their access networks (the entire connection infrastructure and providing service to users) in conventional wire network technologies for fiber optic networks, to increase the capacity and reach of their networks in order to provide more services to more subscribers near and far. To facilitate this capacity and reach, fiber optic networks must employ additional fiber optic cables, hardware and components, resulting in increased installation time, cost and maintenance. This makes fiber optic networks more complex, requiring architectures that allow more efficient delivery of fiber optic service. to the subscriber. These architectures typically employ fiber optic network devices, such as optical connection terminals or optical boxes, for example, in branches of the fiber optic network. Fiber optic network devices act to optically interconnect the optical fiber cables of the branch, separate or combine optical fibers into cables of one or more fibers and / or divide or couple optical signals, as needed.

[003] Telecommunications Operators and their Access networks have increasingly taken advantage of passive optical transmission technologies (PON, Passive Optical NetWork) and product solutions compatible with these technologies. Usually these Access networks are designed with “star” or “double-star” topologies, taking advantage of components called Optical Splitters, which are concentrated (“Local Convergence”) or distributed (“Distributed Topology”) to the wide of the external access network, but more commonly, with a primary splitter feeding a set of second-level splitters in “star” topology, each feeding in turn (“double star”) a set of Operator customers.

[004] Power distribution systems for optical signals in data transmission access networks are known in the art. Such systems use optical junction boxes to derive at least one optical fiber from an optical distribution cable, containing a plurality of optical fibers, allowing at least one derived optical fiber, containing a certain optical power, to form a respective derivation cable a be directed, at the end, to a respective optical termination box.

[005] Inside the optical termination box, the optical signals coming from the derived optical fiber are divided into a plurality of user optical fibers, and which are connected with a respective optical cable user terminal (drop cable or access cable), projecting the said optical termination box.

[006] The optical termination box can present, for example, the construction object of patent BR102016029000-7, with multiple outputs for the connection of multiple optical user terminal cables, from an optical distribution or branch cable, received in said optical box.

[007] These known distribution systems, using optical boxes, are developed, according to the network installation project, to provide the separation of the optical fiber signals from a multi-fiber distribution cable, into one or more optical branch cables . Each derivative optical cable contains at least one derived fiber and is received and retained, by connectorization or by fusion, in an optical termination box, so that at least one derived optical fiber can be connected, by connectorization or by fusion, with a respective user terminal optical cable ("drop" cable or access cable), projecting a respective exit opening of the said optical termination box.

[008] In the construction of an optical termination box described in document BR102016029000-7, mentioned above, the single fiber derivation optical cable has its optical fiber spliced / fused to an optical fiber extension that is divided one or more times, with balanced optical power, in a plurality of divided optical fibers, which are connected, by connectorization or fusion, to respective output adapters provided in the output openings of the termination box.

[009] When the derivation cable has multiple derived optical fibers, each one can be connected directly or via fiber optic extensions, divided with balanced optical power or even not divided, and using connectorization or fusion, to a output adapter. Each output adapter can be easily and quickly attached to a connector on a user terminal cable.

[0010] Another construction of an optical termination box can be seen in document US2014 / 0219621 Al, in which the derivation and user termination cables are connected.

[0011] The aforementioned constructions were developed to facilitate the reception and retention operations, in the optical termination box, without the risk of loosening the derivation cable, usually of the multifiber type. In addition, these constructions are intended to facilitate the operations of connecting the optical branch cable or fibers to the box outlet adapters, carried out by the installer operator, preferably outside the installation site of the termination box and before closing from the box.

[0012] Despite the constructive and operational advantages achieved with the well-known optical power distribution systems, using junction and termination boxes, these systems do not guarantee an optimized optical signal at all outputs of the network boxes. When the distribution cable is of the multifiber type, the derivations made by separating one or more fibers from the distribution cable, for the formation of the terminal cables along the network, do not present the optimal split ratios in relation to the power demands of certain patterns of distribution networks in urban environments, of higher density, and in rural environments of lower density of users.

[0013] In addition, the multi-fiber solutions on pre-connected bus use multi-fiber cables or bundles of cables, and naturally have a very high diameter and weight. These characteristics represent a higher load (weight) to the posts, with direct implications on the hardware used and, in extreme cases, on the remodeling requirement infrastructure (exchange of posts). In cases of maintenance or fiber breakage, it makes repair and restoration of the service difficult.

[0014] Even in cases of use of an optical distribution cable with a single optical fiber, the derivations of that single fiber, along the network, are carried out, in a balanced way, in each junction box, both in a first stage of derivation division, as in a second division stage, for the formation of fiber optic extensions to be connected to the respective user terminal cables. Thus, even in this case, the distribution of optical power does not present the optimal split ratios in relation to the power demands of the usual distribution network standards in urban and rural environments.

[0015] This known distribution of the optical power available in a distribution cable is carried out, along the network, within standards defined by the optical power of the fibers of the distribution cables and of any symmetrically divided optical fibers, making it difficult and even preventing a distribution of optical power in "cascade", with the derivations and possible divisions not providing optical powers specifically sized according to the needs of the different terminal users to be served and also with the characteristics of certain network topologies.

[0016] In many cases, this distribution, which is not very flexible and is not capable of adapting the optical power available to a user, ends up leading to deficiencies in the available power or requiring the use of optical power attenuators, in order to achieve desired power adequacy, with consequent loss of energy.

[0017] In addition to the aspects mentioned above and related to the difficulty of optimization in the distribution of the optical powers demanded throughout the network, in cases where the distribution is carried out with little or no pre-connectorization of optical cables and optical extensions, this distribution becomes even more problematic when carried out in the field. SUMMARY OF THE INVENTION

[0018] Due to the limitations of the known solutions as mentioned above, the present invention has the objective of providing a power distribution system in optical fiber access networks, using optical termination boxes and allowing an optical power distribution in " cascade ", with derivations and possible divisions providing optical powers sized according to the needs of different terminal users.

[0019] The present invention relates to a power distribution system in optical fiber access networks using optical boxes, comprising an optical box bus containing at least one optical junction box connected in sequence and terminated by a termination box . The at least one optical junction box receives a distribution or diversion cable formed by a single optical fiber, providing a certain optical input power, said optical junction box having an input divider to divide, unbalanced, the optical input power received in the bus optical box in two parts. A first part of the optical input power is conducted to an output splitter. The output divider dividing the first part of the optical power into optical powers that are transferred to the respective user terminal optical cables. A second part of the optical input power is conducted to a next optical bus box by a continuation cable, and so on until the last optical termination box is reached, in which the optical input power is fully available to the optical cables user terminals. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The system in question will be described below, making reference to the attached drawings, given by way of example only and in which:

[0021] Figure 1 represents a diagram illustrating a portion of a network of optical fibers formed by a plurality of junction boxes and a termination box, the first of which receiving a distribution cable containing a single optical fiber and connected to a termination box input adapter.

[0022] Figure 2 represents a block diagram through which the design guidelines of an optical box bus are taken.

[0023] Figure 3 illustrates a preferred embodiment of the present invention, where the bus comprises sequentially connected optical junction boxes, terminated by a termination box.

[0024] Figure 4 represents an embodiment of the present invention, where the optical boxes are each formed in two box bodies and with the final terminating optical box formed in one body.

DESCRIPTION OF THE INVENTION

[0025] As previously mentioned and illustrated in Figure 1, the simultaneous termination and derivation system of optical fibers in data distribution networks, uses optical junction boxes 10 and optical termination boxes.

[0026] For contextual purposes of the present invention, an optical junction box is an optical box with a first splitter, which divides an incoming optical power into a continuation optical power, which will be forwarded the other optical box, and an optical terminating power, which will be sent to a second divider (splitter) to divide the optical power to be delivered to users (drop cable). In addition, an optical termination box is defined as a optical box comprising only one divider, which divides the incoming optical power to be delivered to users (drop cable).

[0027] Preferably, the optical boxes used are tubular and airtight optical boxes, comprising housing for splitters, bases and covers for different reinforced optical adapters. Examples of optical boxes that can be used are the CTOP-L 9P, CTOP-L 10P and CTOP-L 10P Generation 2 models, as well as the optical box disclosed in patent BR102016029000-7. However, it is clear to a person skilled in the art that any optical box with unbalanced splitter configuration followed by a balanced splitter can be used, as well as a box with only balanced splitter for the last box, according to the bus revealed in the present invention.

[0028] The optical box 10 can be formed with a closed end and provided with an entrance opening (not shown) to receive an optical distribution cable CD, containing an optical fiber (figure 1) or a plurality of optical fibers (figure 4), and an open end that is closed by a lid 20 which can be of the sealed or removable type.

[0029] Preferably, the CD distribution cable, of an optical fiber, is connectorized, that is, provided with a CE input connector of any suitable construction, to be coupled and retained in a watertight AE input adapter mounted , at the entrance opening of the housing 10. Non-limiting examples of non-reinforced connector are the SC model.

[0030] More preferably, the distribution cable CD, formed by an optical fiber and providing a certain optical input power, can be preconectorized and connected to the optical box 10 by means of a reinforced connector external to the box.

[0031] In the example shown in Figure 1, the distribution cable CD contains only one optical fiber having a predetermined optical input power and which is connected, through the CE input connector and by the input adapter AE or by optical fusion (not shown), to an extension of optical fiber EFO internal to the box 10 and which, in the illustrated example, is provided with a connection connector CL that is coupled to the input adapter AE.

[0032] The fiber optic extension EFO is routed to a DE input splitter device in which it is divided into a continuation fiber FC and at least one termination fiber FT. The FT terminating fiber, in turn, is conducted to a DS output splitter device, in which it is divided into multiple FU user fibers, each of which is selectively connectable, by fusion or by connectorization, with respective C connectors and adapters AS output ports, which are provided in openings generally located in the cover 20, to respective optical cables CT user terminals which can be preferably connectorized.

[0033] According to the system now proposed, a desired portion of the incoming optical power, available in the distribution cable CD (which can be defined by a branch cable) with a single optical fiber, is divided from the latter, in a way generally unbalanced in the DE input splitter, in at least one FT termination fiber and in an FC continuation fiber.

[0034] The FT terminating fiber has an optical power generally lower than that of the FC continuation fiber and sized according to the needs of the users to be served by it. For this purpose, the FT terminating fiber is conducted, with or without splicing by EF fusion of intermediate harnesses, to the DS output splitter device, in which it is divided into multiple FU user fibers, which may have equal or unbalanced optical powers, to provide different connection points for users with different optical power demands.

[0035] The FC continuation fiber, containing any remaining optical input power in optical box 10, may be provided with a connector CS output adapter to be coupled to an AS output adapter provided in a corresponding opening in box 10, usually on cover 20. The AS output adapter is coupled to the CS output connector of a DC continuation cable to be conducted to a next optical termination box 10. Such coupling between optical boxes is repeated successively until a terminating optical box 12 is reached in which the incoming optical power is integrally made available to the user CT terminal cables, to be selectively connected to said optical box 12.

[0036] The branching system proposed by the present invention consists of one or more optical branching boxes 10 and an optical terminating box 12, forming a bus of optical boxes. In this way, a first optical branch box 10 receives an optical input power, which is routed inside the box and connected to a DE input divider that will divide the optical power into a continuation optical power and an optical power of termination. The optical continuation power will be routed to a new optical junction box 10, or to the optical termination box 12. The optical termination power will be routed to a balanced DS output splitter, which will divide the optical power between users that will be served by the optical box.

[0037] As can be seen in Figure 1, two optical junction boxes 10 and an optical termination box 12 are illustrated, where the continuation output of a first box is the distribution cable of the next optical box on the bus.

[0038] The proposed system allows optical junction boxes 10, provided with a continuation output and termination outputs, and an optical termination box 12, provided with termination outputs, to be sequentially connected on a predetermined bus that receives an optical CD distribution cable with a fiber. [0039] The bus presents, in the optical junction boxes, reasons for unbalanced division of optical power, between the continuation output and the termination outputs, and reasons for balanced or unbalanced division between the termination outputs of each optical box.

[0040] The design of the bus should take into account some parameters, such as the number of users that must be served by the bus, the optical input power of the OLT (optical Une terminal of the optical line terminal), as well as the minimum and maximum that must be delivered to the ONU (optical network unit) or ONT (optical network terminal - terminal of optical network), that is, to the terminals present in the premises of the users.

[0041] According to the international standard ITU-T G.984, “Classes” of “Loss Budget” are defined that must be respected by the OLT and ONU transmission and reception equipment referenced above. Today, a standard recognized in this standard is Class C +, which provides the value of 32 dB (Thirty-Two decibels) as the maximum attenuation limit between OLT and ONT devices, and this value is used as a reference for the preferred embodiments presented here of the invention.

[0042] However, other OLT and ONT devices on the market have Loss Budget values that vary between 30 dB and 34 dB. Even so, other existing values / classes or future evolution of technology can be considered equally for the invention, since the demonstrations and concepts can be validated for different values / classes of equipment.

[0043] In addition to the optical power considerations, the number of users that will be served by the bus is also a factor to be considered in the construction of the bus. [0044] The first is the division ratio (1: N) of the equipment door. As the optical network has a point-multipoint technology, it is necessary to define whether each port of PON equipment will be shared for 32, 64, 128 ONT (optical network terminal) or according to technologies available in the market.

[0045] In the embodiments illustrated in the present invention, the solution is based on pre-connectorized optical terminal boxes with balanced DS output dividers with 8 outputs, this metric already guides the number of boxes that are arranged in the cascade. For example, for output dividers with a 1: 16 split ratio, 4 optical boxes would be needed, while for 1: 4 output dividers, 16 optical boxes would be needed.

[0046] Preferably, the split ratios are designed so that the optical signals, available at the termination outputs of each optical junction box and the optical termination box, meet the optical sensitivity of the UN. This premise allows that the optical power delivered to users does not show much variation, which helps to prevent the UN from recognizing the optical signal or saturating it.

[0047] However, all losses in the system must be taken into account, such as losses along the length of the cable, and losses due to the fusion or connectorization of the optical fiber.

[0048] Figure 2 illustrates a block diagram through which the design directives of a bus of optical boxes are taken, in order to consider the losses in the system and still meet the maximum users.

[0049] As can be seen, A represents the optical power emitted by the OLT transceiver (optical port), and due to the length of the optical fiber cable to the bus region, there is a characteristic loss of the P _f fiber that preferably must be considered in the design of the bus. Thus, the variable P represents the characteristic loss of the fiber by the distance to the first bus box. [0050] The optical power that actually reaches the first box of the bus, through a CD distribution cable can be calculated as follows:

A— Pf = A '

where: A = power emitted by the transceiver; P _j = characteristic loss of the fiber by the distance to the first box; and A '= input power of the first optical box on the bus.

[0051] According to the present invention, the junction boxes 10 have an input divider DE with unbalanced configuration, where the division ratio can be defined by i / ni, where mi is the portion of the optical power OUT routed to the fiber continuation FC of the first optical box and ni is the portion of the SU user output optical power routed to the FT termination fiber.

[0052] As shown in figure 1, the FT termination fiber is sent to a DS output splitter, which divides the optical power between the user terminal cables in a balanced way (drop cable). As the optical power provided by the FT termination fiber is divided, each terminal user will receive an attenuated power with respect to it. Such attenuation can be defined by Psu, which refers to the loss considered up to the user.

[0053] Thus, the power delivered to users at the terminating output of the first optical box can be expressed by:

[0054] The Psu value will depend on the amount of 1: N division of the balanced output divider DS of the optical box. In the preferred embodiment of the present invention, where the balanced divider has a 1: 8 configuration, the PSU value is equal to 10 dB, for the purpose of calculations considering the technology currently available. However, other reasons splitting can be used, such as 1: 4, 1: 8 or 1: 16 balanced. Thus, a technician in the subject should consider the PSU value referring to the number N outputs of output divider 1: N.

[0055] To ensure that a second optical box can be included on the bus and still meet the demand for optical power from users, the inventors of the present invention have developed the following criteria:

if - - P _su ³ B, one more nl junction box can be inserted

on the bus; and

if— n _í - P _s ^ύ _u ^u <B, the bus must be completed with the termination box;

where: B is the Loss budget up to the user's UN. In this sense, the usual reference according to the ITU-T G.984 technical standard is 32dB.

[0056] As shown in Figure 2, the AVnii optical power delivered to a second optical box is divided by a second input splitter

DE, which has a split ratio! ¾ / ¾. In this way, the termination output delivered to users of the second box can be expressed by:

[0057] Thus, analogously to the check made for the first box, to ensure that a third optical box can be included on the bus and still meet the demand for optical power from users, one should check:

if zrzr - Psu ³ B, one more junction box can be inserted in the bus;

if— m ₁ * -n ₂ P _su ^U <B, the bus must be completed with the termination box.

[0058] For a third optical junction box, the optical input power will again be divided by the input divider DS, with division ratio m ₃ / n _{3 In} this way, the termination output delivered to the users of the second box can be expressed per: THE!

- P,

m ₁ * m ₂ * n ₃ su

[0059] Thus, analogously to the check made for the first and second boxes, to ensure that a fourth optical box can be included on the bus and still meet the demand for optical power from users, one should check:

if A!

m ₁ * m ₂ * n ₃ P _su ³ B, one more junction box can be inserted in the bus;

if - A '

m ₁ * m ₂ * n ₃ P _su <B, the bus must be completed with the termination box.

[0060] Through these metrics, it is possible to anticipate from the design data which is the ideal configuration of the bus to meet a project demand. The metrics can be generalized to calculate the possibility of an optical y-derivation box on the bus, through:

where A 'is the input power of the first optical box on the bus;

y is the index referring to the optical box to be included in the bus;

mi is the split value for the second part of the optical power, routed to the continuation cable (CC), of the i-th optical box;

n _yl is the division value for the first part of the optical power, routed to the termination cable (CT), optical index box immediately before the box to be included in the bus.

[0061] If the inequality is satisfied, the optical derivation box of index y can be included in the bus. Otherwise, the bus must be terminated by the terminating optical box 12. In this way, the number of optical junction boxes can be obtained. [0062] According to a preferred embodiment, the nii / ni division ratio of the optical boxes along the bus is always decreasing from the first box to the last box, that is:

[0063] This premise ensures that the boxes closest to the transceiver (OLT) must transfer the greater power to the DC continuation cable than the next optical boxes on the bus.

[0064] Furthermore, since m and n represent the splitting ratio of the DE input splitter, the following premise can be obtained:

m _{i +} n _i = 1, where i = 1, 2, 3, ..., k represents the number of the optical box on the bus.

[0065] Preferably, the split ratio of the input divider DE of each of the optical junction boxes 10 has a split ratio between 95/05 and 55/45/40, the numeral before the bar being the percentage of the power sent to the next optical box 10 of the system and the numeral after the bar the percentage of the power sent to the access cables (drop).

[0066] A preferred execution mode for the proposed system, not limited to this, comprises 7 optical junction boxes 10 connected sequentially, terminated by a termination box 12, as illustrated in Figure 3.

[0067] In this preferred configuration, the optical boxes are configured with the following division reasons: in the first junction box of the system, 90% of the incoming optical power is sent to the subsequent junction box and 10% of the incoming optical power it is directed to the access cables (drop); in the second junction box, 90% of the optical power available at the entrance of that box is sent to the subsequent junction box and 10% of the optical input power in that second box is directed to the access cables (drop); on the third junction box, 90% of the available optical power at the entrance of this box is sent to the subsequent junction box and 10% of the incoming optical power in this third box is directed to the access cables (drop); in the fourth junction box, 85% of the optical power available at the entrance of that box is sent to the subsequent junction box and 15% of the optical input power in that fourth box is directed to the access cables (drop); in the fifth junction box, 80% of the optical power available at the entrance of that box is sent to the subsequent junction box and 20% of the optical input power in that fifth box is directed to the access cables (drop); in the sixth junction box, 70% of the optical power available at the entrance of that box is sent to the subsequent junction box and 30% of the optical input power in that sixth box is directed to the access cables (drop); in the seventh junction box, 40% of the optical power available at the entrance of that box is directed to the access cables (drop) and 60% of the optical input power in that seventh box is sent to the eighth and last box of this example of installation of the system, which box defines an optical termination box 10, with its outputs for the access cables (drop) each of which receives, in a balanced or unbalanced way, a portion of the optical input power in that last optical termination box 10 . Such configuration presents the maximum use of the optical power for an application where 64 users must be served.

[0068] Below are the optical losses calculated for this configuration, in dB

[0069] As illustrated in Figure 3, the attenuation of data sending (upstream) in the OLT is -29.645 dB. In this embodiment, the optical boxes used have pre-connectorized outputs, and the optical losses in the connection by connector are considered, as well as the losses in the cable length up to the first optical box. The spacing between the optical boxes from the first was 0.4 km, and the losses related to this distance were neglected. However, if the boxes have greater distances from each other, the losses along each DC continuation cable should preferably be considered.

[0070] Usually, and for the purposes of the tests carried out in the present invention, the losses in the cable in the direction of transmission, wavelength of 1490 nm, is -0.26 dB / Km and in the cable in the direction of reception, in length 1310 waveform is -0.35 dB / Km. In addition, optical losses are considered by cable connection by fusion of -0.1 dB, and by connectorization of -0.3 dB. However, a technician on the subject will envision that new forms of connection or different cables will have their respective losses, which can be considered in the design of the optical power distribution bus proposed in the present invention.

[0071] Although the preferred embodiment of Figure 3 uses an output splitter DS 1: 8, a person skilled in the art will observe that other configurations can be used, such as 1: 4 or 1: 16, depending on the available optical power and the sensitivity of the users' UN.

[0072] In the following, a second embodiment of the present invention will be described, where the bus comprises 7 optical junction boxes 10 connected sequentially, terminated by a termination box 12. The division ratio of the optical boxes is 90/10, 95 / 5, 90/10, 85/15, 80/20, 70/30 and 60/40, the numeral before the bar being the percentage of the power forwarded to the next optical box 10 of the bus and the numeral after the bar the percentage of the power forwarded to the access cables (drop).

[0073] Below are the optical losses calculated for this alternative configuration, in dB

[0074] The data transmission attenuation calculated in the OLT is -29, 445 dB. Again, losses in the cable in the direction of transmission and reception and optical losses by connection and fusion are considered. Thus, it should be noted that the premise of the division ratio m iii of the optical boxes along the bus is always decreasing from the first box to the last box, although preferred, it is not essential for the design of the bus according to the present invention. .

[0075] These realization examples can be executed entirely with pre-connectorization between the elements, thus avoiding user errors and making installation quicker and easier.

[0076] Although the two solutions (multi-fiber and single-fiber bus) use pre-connectorized cables, the issue of lengths (cable runs) is advantageous in the embodiment where the cable is monofiber, illustrated in Figure 1. This is due to to the reduced diameter of the monofiber cable, thus allowing simple storage of the excess cable in accessories specific to the CTOP-L optical boxes.

[0077] On the other hand, the current multifiber cables on the market, due to their diameter and rigidity, do not allow storage in the optical boxes themselves, so they are manufactured in specific lengths for each project and installed without considering leftovers for maneuvers and maintenance. Thus, in multi-fiber solutions, the designer has to accurately collect this information in the field. [0078] Fixed length monofiber cables can be manufactured without this concern for accuracy because any leftovers can be easily stored. Even with an accurate survey, unforeseen events can occur in the installation and exact lengths make replacement difficult in case of maintenance.

[0079] As can be seen from the above, two or even more DE input and DS output splitter devices can be used to provide different dividing and subdividing reasons, usually unbalanced, to give the system great versatility to adapt to the real needs of different users of the fiber optic network, minimizing or even eliminating the need for the provision of optical attenuators.

[0080] Considering the characteristics of the proposed system, which allows to provide a versatile installation solution, using previously sealed optical termination boxes for posterior and simple connection of CD distribution, CT termination and DC continuation optical cables, the dividing devices input DE and output DS can be previously produced in a factory environment and according to the potential characteristics of the network installation to be supplied.

[0081] When using unsealed optical boxes 10 and CD distribution cables, termination cables and non-connected DC continuation cables, the different optical connections are made by fusion, usually at the location of the network installation.

[0082] As schematically illustrated in figure 4, it may be convenient that each optical branch box 10 of the network is formed by a first portion of box 10A and a second portion of box 10B, spaced from the first portion of box, according to the topology characteristics of the network. [0083] In this construction, the CD distribution cable has its CE input connector, preferably pre-assembled, coupled to an AE input adapter of the first box portion 10A of the first junction box 10, to be connected to an extension cable. EFO fiber internal to the first box portion 10A and provided with a CL connection connector that is coupled to the AE input adapter. The EFO fiber optic extension is received in a DE input splitter device, arranged inside the first box portion 10 and in which the optical fiber extension is divided into a continuation fiber FC and an FT termination fiber, which they are preferably pre-connected, each with a respective connector C which is coupled to the respective output adapter AS, provided in a respective outlet opening (not shown) of the first housing portion 10A.

[0084] One of the AS output adapters of the first box portion 10A is coupled with a C connector of a DC continuation cable, preferably pre-connectorized at both ends and having its opposite C connector, coupled to an input adapter AE of the first box portion 10A of a subsequent branch box 10 of the network.

[0085] To the other AS output adapter of the first box portion 10A, of said first optical box 10 of the network, a C connector of a CDT terminal branch cable is attached, preferably preconectorized at both ends and having its C connector opposite, coupled to an AE input adapter of the second box portion 10B of the same first optical box 10 of the network.

[0086] The second portion of box 10B houses a DS output splitter device in which an FT terminating optical fiber is received, preferably preconectorized and having its C connector coupled to the C connector of the CDT terminal branch cable, by means of the adapter AE input. [0087] In the DS output splitter device, the FT terminating optical fiber is divided into multiple FU user optical fibers, each of which is selectively connectable, by connectorization, preferably by pre-connectorization, with respective C connectors and output adapters AS, which are provided in outlet openings (not shown) of the second housing portion 10B and in which respective optical user CT terminal cables are connectable which are preferably connectorized, as shown in the drawing figures.

[0088] The individual construction of each optical junction box 10 of the optical fiber network can be done in a single portion, as shown in figure 1, or in two portions of box, as illustrated in figure 4, with the same network containing both types of construction. However, the terminating optical box 10 has only a single portion, as it houses only the DS output splitter. The configuration of separate boxes in box portions is interesting since the bus operator can add the 10B termination box portions only when necessary, that is, when there were subscribing users at the location of the optical box.

[0089] A preferential execution mode, not limited to this one, provides for the system to run entirely with pre-connectorization between the elements, and that pre-connectorization can be applied to all or part of the elements. This avoids user errors and makes system installation quicker and easier.

[0090] However, it should be understood that the distribution cable CD can be received and axially locked inside the box 10 without the use of CE input connector, as described, for example, in patent application BR 10 2016 029000-7 .

[0091] Considering the characteristics of the proposed system, which allows providing a versatile installation solution, using optical boxes bypass and termination cables previously sealed for later and simple connection of optical fibers and preconectorized optical cables, the DE input and DS output splitter devices can be previously produced in a factory environment and according to the potential characteristics of the network installation to be provided.

[0092] Thus, the present invention is advantageous since the elements of the access network (distribution boxes and optical termination with embedded splitters) are arranged in the form of a bus or sequential cascade, that is, a first element receives the signaling optics that come from the concentrator equipment (usually a transmission over kilometers), distribute part of that signaling to a group of nearby customers (tens or hundreds of meters) and send another part of the optical signaling to the second element of the sequence and so on , following rules and even the limits imposed by the PON transmission technology itself.

[0093] A second differential of this solution is that, unlike other transmission technologies where complex calculations and the use of proprietary software tools are needed to define which element / splitter should be used in each location (physical) and position within a specific sequence, in this case the solution foresees the use of a bus with fixed elements / splitters. Both the quantity of elements in the cascade, as well as specific attributes such as splitting ratios and optical signal attenuations, are defined in advance by the manufacturer, and simply installed by the Operator off the Operator's service region.

[0094] This avoids the need for the Operator to carry out such calculations and definitions during the executive project for each section of the access network, facilitating the control of the application of the elements during construction, reducing the types of elements / products that this will keep on construction and maintenance (replacement) inventory, among other tangible benefits that can be listed.

[0095] A third differentiating factor of the solution is the use of monofiber optical cables, according to the preferred embodiment of Figure 1 of the present invention. Other optical solutions use multifiber cables (several optical fibers within the core of a cable) or bundles of cables off the access network, while the proposed solution is based on the interconnection between elements of the access network using only single fiber cables (a single fiber inside the cable core), which is possible through conjunction with splitters in disposition and planned sequences.

[0096] Solutions with multifiber cables naturally have a diameter and weight much higher than those of a single fiber solution, incurring greater occupation and load (weight) than the posts, with direct implications on the hardware used and, in extreme cases, on the remodeling requirement infrastructure (exchange of posts).

[0097] The fourth distinguishing feature to highlight is the construction of all elements (boxes / splitters and cables of the Access network) with pre-connectorized characteristic, that is, the elements are provided with optical connectors prepared at the factory, for interconnection “ plug-and-play ”, quick and simple.

[0098] Although only a few examples of embodiments of the termination and derivation system of optical fibers in question have been presented here, it should be understood that changes in the shape and layout of the different component parts of the system can be made, without escaping. of the proposed inventive concept.

Claims

1. Communication and power signal distribution system in optical fiber access networks using optical boxes (10) comprising a bus of optical boxes containing at least one optical junction box (10) connected in sequence and terminated by a termination (12); wherein the at least one optical junction box (10) receives a distribution or diversion cable (CD) formed by a single optical fiber providing a certain optical input power (A), the optical junction box (10) having an input divider (DE) to unbalanced the optical input power (A) received in the optical box (10) of the bus in two parts; wherein a first part of the optical input power (A) is conducted to an output divider (DS), the output divider (DS) dividing the first part of the optical power into optical powers that are selectively transferred to respective terminal optical cables (CT) user, in which a second part of the incoming optical power (A) is conducted to a next optical box (10, 12) on the bus by a continuation cable (DC) formed by a single optical fiber, and so successively until the last optical termination box (12) is reached, in which the optical input power is integrally made available to the user's optical terminal cables (CT); characterized by the fact that each optical junction box (DE) has, along the bus, a division ratio m rii, where mi is the division value referring to the second pre-defined part of the optical power, routed to the continuation (CC) of the i-th optical box and ¾ is the split value referring to the first pre-defined part of the optical power, sent to the termination cable (CT), from the optical index box immediately before the box to be included in the bus; where the nii / ni division ratio of an optical junction box (DE) along the bus is greater than or equal to the division ratio of the next box on the bus, as follows: m _l m ₂ m ₃ rrii

ni ~ ⁿ 2 ~ ⁿ 3 ~ ⁿ i

2. System according to claim 1, characterized by the fact that it comprises y optical junction boxes (10) and an optical termination box (12), in which the number y of optical junction boxes (10) is calculated according to the following inequality:

where A 'is the input power of the first optical box on the bus; y is the index referring to the optical box to be included in the bus; mi is the split value for the second part of the optical power, routed to the continuation cable (CC), of the i-th optical box; n _yl is the division value referring to the first part of the optical power, routed to the termination cable (CT), of the optical index box immediately before the box to be included in the bus;

Psu is the loss of optical power up to the user;

B is the Loss budget up to the user's optical network unit (ONU); where, if the inequality is satisfied, the optical y-derivation box can be included on the bus; otherwise, the bus must be terminated by the optical termination box (12).

3. System, according to claim 2, characterized by the fact that the Loss Budget B value is between 30 dB and 34 dB.

System according to any one of claims 1 to 3, characterized by the fact that the dividing ratio of the input divider (DE) of each of the optical junction boxes (10) is between 95/05 and 55 / 45, with the numeral before the bar the percentage of the power forwarded to the next optical box (10) of the system and the numeral after the bar the percentage of the power forwarded to the output splitter (DS) and to the terminal optical cables (CT) user (drop).

System according to any one of claims 1 to 4, characterized in that it comprises seven optical junction boxes (10) and an optical termination box (12), in which the portion of the incoming optical power in each optical box (10) of the network, is conducted, and divided, with respective pre-defined optical powers unbalanced from the optical boxes (10) of the derivation in the ratio of 90/10, 90/10, 90/10, 85/15, 80 / 20, 70/30, 60/40, with the numeral before the bar the percentage of the power forwarded to the next optical box (10) of the system and the numeral after the bar the percentage of the power forwarded to the access cables (drop) .

6. System according to any one of claims 1 to 5, characterized in that the optical junction box comprises an input adapter (AE) connected to receive a distribution cable

(CD) connectorized and of pre-defined length with input connector

(CE).

7. System according to any one of claims 1 to 6, characterized in that the output divider (DS) of each optical box (10, 12) is a 1: 4 or 1: 8 or 1:16 splitter balanced.

System according to any one of claims 1 to 7, characterized in that each optical box (10) comprises an output adapter (AS) connected to be coupled to the output connector (C) of a continuation cable (DC) connectorized from a single optical fiber.

System according to any one of claims 1 to 8, characterized in that each optical junction box comprises an optical fiber extension (EFO) internal to the box (10), provided with a connection connector (CL) , in which the optical fiber extension (EFO) is conducted to the input splitting device (DE), in which it is divided into a continuation fiber (FC) and at least one termination fiber (FT).

System according to any one of claims 1 to 9, characterized in that the terminating fiber (FT) is conducted to an output splitting device (DS) and is divided into multiple user fibers (EU), each of them being selectively connectable, by connectorization, with respective connectors (C) and output adapters (AS).

System according to any one of claims 1 to 10, characterized in that each optical junction box (10) comprises a continuation fiber (FC), containing the second part of the optical input power in the optical box ( 10), in which the continuation fiber (FC) is provided with an output connector (CS) to be coupled to an output adapter (AS) provided in a respective opening of the box (10).

12. System according to any one of claims 1 to 11, characterized by the fact that output adapters (AS) are provided in openings located on the cover (20), for connection with optical user terminals (CT) cables.

13. System according to any of claims 1 to 12, characterized in that each branch box (10) of the network comprises: a first portion of box (10A), in which an optical signal is transmitted by the cable optical distribution (CD) or continuation (CC) is received and divided and transmitted on an optical bypass terminal cable (CDT) and on an optical continuation cable (CC); and a second box portion (10B) in which the optical signal that is transmitted by the terminal bypass optical cable (CDT) is received and divided and transmitted in multiple optical fibers, with respective optical powers to be transferred, by connectorization, to the respective user optical terminal (CT) cables.

14. System according to claim 13, characterized by the fact that the second box portion (10B) is distanced from the first box portion (10A) and connected to it by the terminal branch cable (CDT).

15. Communication and power signal distribution system in optical fiber access networks using optical boxes (10) comprising an optical box bus containing seven optical junction boxes (10) connected in sequence and terminated by a termination box ( 12); in which the optical junction boxes (10) receive a distribution or diversion cable (CD) formed by a single optical fiber providing a certain optical input power (A), each of the optical junction boxes (10) having a input divider (DE) to divide, in an unbalanced way, the optical input power (A ') received in the optical boxes (10) of the bus in two parts; wherein a first part of the optical input power (A ') is conducted to an output divider (DS), the output divider (DS) dividing the first part of the optical power into optical powers that are selectively transferred to the respective optical cables user terminals (CT), in which a second part of the incoming optical power (A) is conducted to a next optical box (10, 12) on the bus by a continuation cable (DC) formed by a single optical fiber, and so on until the last optical termination box (12) is reached, in which the incoming optical power is integrally made available to the user's optical terminal cables (CT); characterized by the fact that the portion of the incoming optical power in each optical box (10) of the network, is conducted, and divided, with respective unbalanced optical powers of the optical boxes (10) in the ratio of 90/10, 95 / 05, 90/10, 85/15, 80/20, 70/30, 60/40, the numeral before the bar being the percentage of the power forwarded to the next optical box (10) of the system and the numeral after the bar o percentage of the power sent to the access cables (drop).