ES2869464A2 - System for distributing power and communication signals in optical fibre access networks - Google Patents

Abstract

"Communication and power signal distribution system in fiber optic access networks". The system comprises an optical box busbar containing at least one optical junction box (10) connected in sequence and terminated by a termination box (12). The optical branch box (10) receives a distribution or branch cable (CD) formed by a single optical fiber, which supplies input optical power (A ') and has an input splitter (DE) to divide, so unbalanced, the input optical power (A ') received in the optical box (10) of the busbar into two parts: one part is conducted to an output divider (DS) that divides the first part of the optical power into optical powers selectively transferred to the respective optical terminal cables (CT) of the user, and another part is conducted to a next optical box (10, 12) of the busbar by a continuation cable (CC), until reaching said last optical termination box (12 ).

Description

DESCRIPTION

COMMUNICATION AND POWER SIGNAL DISTRIBUTION SYSTEM IN

FIBER OPTIC ACCESS NETWORKS

FIELD OF THE INVENTION

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

PREVIOUS TECHNIQUE

Fiber optics are increasingly being used for a variety of broadband applications, including voice, video, and data transmission. As a result of the growing demand for broadband communications, cable and telecommunication service providers and / or operators are expanding their access networks (all connection infrastructure and service provision for users) in conventional wired network technologies. Metals for fiber optic networks, to increase the capacity and reach of their networks to provide more services for more near and distant subscribers. 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 the most 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 branch fiber optic cables, separate or combine optical fibers into one or more fiber cables, and / or split or couple optical signals as needed.

Telecommunications operators and their Access networks have increasingly taken advantage of Passive Optical Network (PON) technologies 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") throughout the external access network, but more commonly, with a primary splitter feeding in a "star" topology a set of second-level splitters, each one feeding in turn ("double star") a set of operator customers.

Power distribution systems for optical signals in data transmission access networks are known in the art. Said systems use branch optical boxes to branch 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 branch cable. which is directed, at the end, to a respective optical termination box.

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

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

These well-known distribution systems, using optical boxes, are developed, in accordance with the network installation project, to allow the separation of the signals from the optical fibers of a multi-fiber distribution cable, in one or more optical cables of derivation. Each drop optical cable contains at least one branched fiber and is housed and retained, by connectorization or fusion, in an optical termination box, so that at least one branched optical fiber can be connected, by connectorization or fusion, to a respective user terminal optical cable ("drop" cable or access cable), which projects from a respective outlet opening of said optical termination box.

In the configuration of the optical termination box described in BR102016029000-7, mentioned above, the single fiber drop optical cable has its optical fiber modified / fused to an optical fiber extension that is split 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 arranged in the output openings of the termination box.

If the drop cable has multiple branched optical fibers, each of them can be connected directly or by means of optical fiber extensions, divided with balanced or even undivided optical power, and using connectorization or fusion, to a respective output adapter. One connector of a user terminal cable can be easily and quickly connected to each output adapter.

Another configuration of the optical termination box can be seen in document US2014 / 0219621 A1, in which the branch and user termination cables are connectorized.

Said previous configurations were developed to facilitate the housing and retention operations, in the optical termination box, without the risk of the drop cable, generally of the multi-fiber type, coming loose. In addition to this, such configurations have the objective of facilitating the operations of connection of the fiber (s) of the bypass optical cable with the box outlet adapters, carried out by the installer operator, preferably outside the box installation site. of completion and before the closing of the box.

Despite the constructive and operational advantages that are obtained with known optical power distribution systems, using branch and termination boxes, these systems do not guarantee an optimized optical signal at all the outputs of the network boxes. If the distribution cable is of the multi-fiber type, the branches made by separating one or more fibers of the distribution cable, for the formation of the terminal cables along the network, do not present the optimized division ratios with respect to to the power demands of certain standards of distribution networks in urban environments, with higher density, and in rural environments with lower user density.

In addition to this, multi-fiber solutions in pre-connectorized busbars use multi-fiber cables or cable bundles, and naturally have a very high diameter and weight. These characteristics represent a greater load (weight) for the poles, with direct implications on the fittings used and, in extreme cases, on the requirement to remodel the infrastructure (change of poles). In cases of maintenance or fiber breakage, it makes repairing and restoring service difficult.

Even in the cases of using an optical distribution cable with a single optical fiber, the derivations of this single fiber, throughout the network, are made, in a balanced way, in each derivation box, both in a first stage bypass division, as in a second division stage, for the formation of the optical fiber extensions to be connected to the respective user terminal cables. Thus, even in this case, the optical power distribution does not present the optimized division ratios in relation to the power demands of the usual standards of distribution networks in urban and rural environments.

This well-known distribution of the optical power available in a distribution cable is carried out, along the network, in standards defined by the optical power of the fibers of the distribution cables and of eventual symmetrically divided optical fibers, making it difficult and even preventing a "cascade" optical power distribution, with the derivations and eventual divisions without providing specifically dimensioned optical powers according to the needs of the different terminal users to be satisfied and also with the characteristics of certain network topologies.

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, so that the desired adaptation is achieved. of power, with the consequent loss of energy.

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 the optical cables and optical extensions, this distribution becomes even more problematic when performed in the field.

DESCRIPTION OF THE INVENTION

In view of the limitations of the known solutions as discussed above, the present invention aims to provide a power distribution system in fiber optic access networks, using optical termination boxes and allowing an optical power distribution in "cascade", with the derivations and the eventual divisions providing dimensioned optical powers according to the needs of the different users of the terminal.

The present invention relates to a power distribution system in fiber optic access networks using optical boxes, comprising a busbar of optical boxes containing at least one optical branch box connected in sequence and terminated by a termination box. At least one optical bypass box houses a distribution or bypass cable formed by a single optical fiber, offering a certain input optical power, said bypass optical box presenting an input divider to divide, in an unbalanced way, the power optical input received in the optical box of the busbar in two parts. A first part of the input optical power is conducted for an output splitter. The output splitter divides the first part of the optical power into optical powers that are transferred to respective optical user terminal cables. A second part of the input optical power is conducted to a next optical box of the busbar by a continuation cable, and so on until reaching said last optical termination box, in which the input optical power is integrally supplied to the Optical user terminal cables.

BRIEF DESCRIPTION OF THE FIGURES

The system in question will be described below, referring to the attached figures, only by way of example and in which:

Figure 1 represents a diagram illustrating a part of an optical fiber network formed by a plurality of branch boxes and a termination box, the first of which receives a distribution cable that contains a single optical fiber and is connected to an adapter. terminal box input.

Figure 2 represents a block diagram through which the project directives of a busbar for optical boxes are taken.

Figure 3 represents an embodiment of the present invention, where the optical boxes are each formed in two box bodies and with the final optical termination box, formed in a single body.

DESCRIPTION OF THE INVENTION

As mentioned and illustrated above in Figure 1, the simultaneous termination and branching system of optical fibers in data distribution networks uses optical branching boxes 10 and optical termination boxes.

For the context of the present invention, an optical branch box is understood to be an optical box equipped with a first divider, which divides an input optical power into a continuation optical power, which will be sent to another optical box, and a terminating optical power, which will be sent to a second splitter for dividing the optical power to be delivered to the users ("drop" cable). In addition to this, an optical termination box is understood to be an optical box that only comprises a splitter, which divides the input optical power to be supplied to the users ("drop cable").

Preferably, the optical boxes used are tubular and hermetic optical boxes, comprising housing for dividers, 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 described in patent BR102016029000-7. However, it is clear to a person skilled in the art that any optical box with an unbalanced divider configuration followed by a balanced divider can be used, as well as a box with only balanced divider for the last box, according to the busbar described in the present invention.

The optical box 10 may have one end closed and provided with an inlet opening (not illustrated) to receive a CD distribution optical cable, containing an optical fiber (Figure 1) or a plurality of optical fibers (Figure 4), and a open end that is closed by a cap 20 that can be of the sealed or removable type.

Preferably, the fiber optic distribution cable CD is connectorized, that is, it is provided with an input connector CE of any suitable configuration, to be coupled and retained in an input adapter AE mounted, hermetically, in the inlet opening of the housing 10. Non-limiting examples of non-reinforced connector are of the SC model.

More preferably, the DC distribution cable, formed by an optical fiber and supplying a certain input optical power, can be pre-connectorized and connected to the optical box 10 by means of a reinforced connector external to the box.

In the exemplary embodiment illustrated in figure 1, the distribution cable CD contains only one optical fiber having a predetermined optical input power and which is connected, through the input connector CE and the input adapter AE or by optical fusion (not illustrated), to a fiber optic extension 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.

The fiber optic extension EFO goes to an input splitter device DE in which it is divided into a continuation fiber FC and at least one termination fiber FT. The terminating fiber FT goes, in turn, towards an output splitter device DS, in which it is divided into multiple FU user fibers, each one of them being selectively connectable, by fusion or by connectorization, to respective connectors C and output adapters AS, which are arranged in generally located openings in cap 20, to respective optical user terminal cables CT which may preferably be connectorized.

According to the system proposed here, a desired part of the input optical power, available in the DC distribution cable (which can be defined by a cable of branch) with a single optical fiber, is divided from the latter, in a generally unbalanced manner in the input splitter device DE, into at least one terminating fiber FT and into a continuation fiber FC.

The FT termination 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, the terminating fiber FT goes to the output splitter device DS, with or without fusion splices EF of intermediate patch cords, in which it is divided into multiple user fibers FU, which can have equal or unbalanced optical powers. , to provide different connection points for users with different demands for optical power.

The continuation fiber FC, which contains the eventual rest of the input optical power in the optical box 10, can be provided with an output connector CS to be coupled to an output adapter AS arranged in a respective opening of the box 10, generally on the cover 20. In the output adapter AS the output connector CS of a DC continuation cable is coupled to be routed to a next optical termination box 10. Such coupling between optical boxes is repeated successively until reaching a box optical termination 12 in which the input optical power is integrally supplied to the user terminal cables CT, which are selectively connected to said optical box 12.

The derivation system proposed by the present invention consists of one or more optical derivation boxes 10 and an optical termination box 12, forming a busbar of optical boxes. In this way, a first optical bypass box 10 receives an input optical power, which is sent inside the box and is connected to an input divider DE that will divide the optical power into a continuation optical power and a terminating optical power. The continuation optical power will be sent to a new optical bypass box 10, or to the optical termination box 12. The termination optical power will be sent to a balanced DS output splitter, which will divide the optical power among the users who will be served by the optical box.

As can be seen in Figure 1, two optical bypass 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 busbar.

The system proposed here 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 in a predetermined busbar that receives a cable. optical distribution CD with one fiber.

The busbar presents, in the optical bypass boxes, unbalanced division ratios of optical power, between the continuation output and the termination outputs, and balanced or unbalanced division ratios between the termination outputs of each optical box.

The busbar project must take into account some parameters, such as the number of users that must be served by the busbar, the optical input power of the OLT (optical line terminal), as well as the minimum and maximum power It must be delivered to the ONU (optical network unit - optical network unit) or ONT (optical network terminal - optical network terminal), that is, to the terminals present at the users' facilities.

According to the international standard ITU-T G.984, "Classes" of "loss balances" (Loss Budget) are defined that must be respected by the OLT and ONU transmission and reception equipment referenced above. Today, a recognized standard in this standard is Class C +, which provides the value of 32 dB (thirty-two decibels) as the maximum limit of attenuation between OLT and ONT devices, and this value is used as references for the preferred concretizations here presented of the invention.

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 the technology can also be considered for the invention, since the demonstrations and concepts can be validated for different values / classes of equipment.

In addition to optical power considerations, the number of users that will be served by the busbar is also a factor to consider in busbar construction.

The first is the division ratio (1: N) of the team gate. As the optical network has a point-multipoint technology, it is necessary to define whether each PON equipment port will be shared for 32, 64, 128 ONT (optical network terminal) or according to the technologies available in the market.

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

Preferably, the split ratios are designed so that the optical signals, supplied at the termination outputs of each optical branch box and the optical termination box, meet the optical sensitivity of the ONU. Such a premise allows that the optical power supplied to the users does not present great variation, which helps to prevent that the ONUs do not recognize the optical signal or saturate it.

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.

Figure 2 illustrates a block diagram through which the project directives of an optical box busbar are taken, to consider the losses in the system and also serve the maximum number of users.

As can be seen, A represents the optical power emitted by the OLT transceiver (optical gate), being that, due to the length of the fiber optic cable to the busbar region, there is a characteristic loss of the Pf fiber that preferably must be considered in the busbar project. Thus, the variable P f represents the characteristic loss of the fiber due to the distance to the first box of the busbar.

The optical power that actually reaches the first box of the busbar, by means of a DC distribution cable, can be calculated as follows:

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

According to the present invention, the branch boxes 10 have an input divider DE with unbalanced configuration, where the division ratio can be defined by m1 / n1, where mi is the part of the optical power OUT sent to the fiber of continuation FC of the first optical box and ni is the part of the user output optical power SU sent to the terminating fiber FT.

As illustrated in Figure 1, the terminating fiber FT is routed to an output splitter DS, which evenly divides the optical power between the user terminal cables ("drop" cable). As the optical power supplied by the terminating fiber FT is divided, each end user will receive an attenuated power relative to it. Such attenuation can be defined by PSU, which names the loss considered up to the user.

Thus, the power delivered to the users at the termination output of the first optical box can be expressed by:

The PSU value will depend on the amount of 1: N division of the DS output balanced splitter 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 purposes of calculations considering the currently available technology. However, other division ratios can be used, such as 1: 4,1: 8 or 1:16 balanced. Thus, a person skilled in the art should consider the PSU value referring to the number N outputs of the 1: N output divider.

To ensure that a second optical box can be included in the busbar and also satisfy the users' demand for optical power, the inventors of the present invention developed the following criteria:

if ^{- - Psu> B} , another junction box can be inserted into the busbar; and

At

if n i ^{Psu < B} , the busbar must be completed with the termination box;

where: B is the loss balance (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.

As shown in Figure 2, the optical power A '/ m1 delivered to a second optical box is divided by a second input divider DE, which has division ratio m2 / n2. Thus, the termination output delivered to the users of the second box can be expressed by:

Thus, analogously to the verification carried out for the first box, to guarantee that a third optical box can be included in the busbar and also satisfy the users' demand for optical power, the following must be verified:

if mi ^{* n2} , another junction box can be inserted into the busbar;

if ^- mi _* - _n - ₂ - ^{Psu <B} , the busbar must be completed with the termination box.

For a third optical branch box, the input optical power will be divided again by the input divider DS, with division ratio m3 / n3. Thus, the termination output delivered to the users of the second box can be expressed by:

Thus, analogously to the verification made for the first and second boxes, to guarantee that a fourth optical box can be included in the busbar and also satisfy the users' demand for optical power, the following must be verified:

yes ^{m "}

^{1 * m2 * n 3} ~ Psu> B

, another junction box can be inserted into the busbar;

- --------- Psu <B

if Tni * m2 * n3, the busbar must be completed with the termination box.

Through these metrics, it is possible to anticipate from the project data which is the ideal busbar configuration to satisfy a project demand. The metrics can be generalized to calculate the possibility of an index junction optical box and in the busbar, through:

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

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

mi is the division value referring to the second part of the optical power sent to the continuation cable (CC), of the ith optical box;

ny-i is the division value referring to the first part of the optical power sent to the termination cable (CT), the index optical box immediately before the box to be included in the busbar.

In the event that the inequality is fulfilled, the index junction optical box and can be included in the busbar. Otherwise, the busbar must be terminated by the optical termination box 12. In this way the number "y" of optical junction boxes can be obtained.

According to a preferred embodiment, the mi / ni division ratio of the optical boxes along the busbar is always decreasing from the first box to the last box, that is:

This premise ensures that the boxes closest to the transceiver (OLT) must transfer the most power to the DC continuation cable than the next optical boxes on the busbar.

In addition to this, since m and n represent the division relation of the input divisor DE, the following premise can be obtained:

mi + ni = 1, where i = 1, 2, 3, ..., represents the number of the optical box on the busbar.

Preferably, the division ratio of the input divider DE of each of the optical bypass boxes 10 has a division ratio between 95/05 and 55/45/40, the numeral before the bar being the percentage of the power sent for 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").

A preferred embodiment for the proposed system, not being limited to this, comprises 7 sequentially connected optical junction boxes 10, terminated by a termination box 12.

In this preferred configuration, the optical boxes are configured with the following split ratios: In the first branch box of the system, 90% of the input optical power is sent to the subsequent branch box and 10% of the power optical input is routed to the access cables (“drop”); In the second branch box, 90% of the optical power available at the input of this box is sent to the subsequent branch box and 10% of the input optical power in this second box is sent to the access cables ("Drop"); In the third branch box, 90% of the optical power available at the input of this box is sent to the subsequent branch box and 10% of the input optical power in this third box is sent to the access cables ("Drop"); In the fourth branch box, 85% of the optical power available at the input of this box is sent to the subsequent branch box and 15% of the input optical power in this fourth box is sent to the access cables ("Drop"); in the fifth junction box, 80% of the optical power available at the input of this box is sent to the subsequent branch box and 20% of the input optical power in this fifth box is sent to the access cables ("drop"); In the sixth branch box, 70% of the optical power available at the input of this box is sent to the subsequent branch box and 30% of the input optical power in this sixth box is sent to the access cables ("Drop"); In the seventh junction box, 40% of the optical power available at the input of that box is sent to the access cables (“drop”) and 60% of the input optical power in this seventh box is sent to The eighth and last box of this example of system installation, a box that defines an optical termination box 10, having its outputs for the access cables ("drop"), each of which receives, in a balanced or unbalanced way, a part of the input optical power in this last optical termination box 10. Such a configuration presents the maximum use of optical power for an application where 64 users must be served.

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

The data send (upstream) attenuation on the OLT is -29.645 dB. In this embodiment, the optical boxes used have pre-connectorized outputs, and the optical losses in the connector connection are considered, as well as the losses along the cable to the first optical box. The separation between the optical boxes from the first one was 0.4 km, the losses relative to this distance were negligible. However, in the case that the boxes have greater distances from each other, the losses along each DC continuation cable should preferably be considered.

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, wavelength 1310 is -0.35 dB / km. In addition to this, the optical losses per cable connection by fusion of -0.1 dB, and by connectorization of -0.3 dB are considered. However, a person skilled in the art will appreciate that new forms of connection or different cables will have their respective losses, which may be considered in the optical power distribution busbar project proposed in the present invention.

Although the preferred embodiment uses a 1: 8 DS output divider, one skilled in the art will appreciate that other configurations, such as 1: 4 or 1:16, may be used, depending on the available optical power and the sensitivity of the ONU. of the users.

Next, a second embodiment of the present invention will be described, where the busbar comprises 7 sequentially connected optical junction boxes 10, 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 bus being the percentage of the power sent to the next optical box 10 of the busbar and the numeral after the bus the percentage of power sent to access cables (“drop”).

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

The data send attenuation calculated in the OLT is -29,445 dB. Again, the losses in the cable in the direction of transmission and reception and the optical losses by connection and fusion are considered. Thus, it is noted that the premise of the mi / ni division relationship of the optical boxes along the busbar, which is always decreasing from the first box to the last box, despite being preferred, is not essential for the busbar project. according to the present invention.

These exemplary embodiments can be executed entirely with pre-connectorization between the elements, thus avoiding user errors and making installation quicker and easier.

Although the two solutions (multifiber and monofiber in busbar) use pre-connected cables, the question of lengths (cable runs) is advantageous in the implementation where the cable is monofiber, illustrated in Figure 1. This is due to the diameter reduction of the single fiber cable, thus allowing the simple storage of the excess cable in accessories of the CTOP-L optical boxes.

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 are installed without considering surpluses for maneuvers and maintenance. Thus, in multi-fiber solutions, the designer has to collect this information in the field accurately.

Fixed length monofiber cables can be manufactured without worrying about accuracy because eventual scraps can be easily stored. Even with accurate compilation, installation issues can occur and exact lengths make replacement difficult for maintenance.

As can be seen from the foregoing, two or even more DE input and DS output divider devices can be used to provide different division and subdivision ratios, generally unbalanced, to give the system great versatility to adapt to real needs. of the different users of the fiber optic network, minimizing or even eliminating the need for the provision of optical attenuators.

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 DC distribution, CT termination and DC continuation connectorized optical cables, the DE input splitter devices and DS output can be previously produced in a factory environment and according to the potential characteristics of the network installation to be supplied.

When unsealed optical boxes 10 and non-connectorized DC distribution cables, termination cables and DC continuation cables are used, the different optical connections are made by fusion, generally at the site of the network installation.

As illustrated in FIG. 3, it may be desirable for each optical branch box 10 in the network to be made up of a first box part 10A and a second box part 10B, separated from the first box part, according to the topology characteristics of the network.

In this construction configuration, the distribution cable CD has its input connector CE, preferably pre-assembled, coupled to an input adapter AE of the first box part 10A of the first branch box 10, to connect to an extension of EFO fiber internal to the first box part 10A and provided with a CL connection connector that is coupled to the AE input adapter. The fiber optic extension EFO is housed in an input splitter device DE, arranged inside the first box part 10 and in which the fiber optic extension is divided into a continuation fiber FC and a terminating fiber FT , which are preferably pre-connectorized, each with a respective connector C that mates to the respective outlet adapter AS, disposed in a respective outlet opening (not illustrated) of the first box part 10A.

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

To the other output adapter AS of the first box part 10A, of said first optical box 10 of the network, is coupled a connector C of a terminal drop cable CDT, preferably pre-connectorized at both ends and having its connector C opposite, coupled to an input adapter AE of the second box part 10B of the same first optical box 10 of the network.

The second part of the box 10B houses an output splitter device DS in which an optical fiber termination FT is housed, preferably pre-connected and having its connector C coupled to the connector C of the terminal branch cable CDT, by means of the input adapter AE .

In the output splitter device DS, the terminating fiber optic FT is divided into multiple user optical fibers FU, each one of them being selectively connectable, by connectorization, preferably by pre-connectorization, to respective connectors C and output adapters AS , which are arranged in outlet openings (not illustrated) of the second box part 10B and to which are connectable the respective optical user terminal cables CT which are preferably connectorized, as illustrated in the figures.

The individual configuration of each branch optic box 10 of the fiber optic network can be made in a single part, as illustrated in FIG. 1, or in two box parts, as illustrated in FIG. 3, one being able to The same network will contain the two types of configuration. However, the optical termination box 10 has only a single part, since it only houses the output splitter device DS. The configuration of separate boxes in box parts is interesting since the bus operator can add the termination box parts 10B only if necessary, that is, if there are subscribing users in the location of the optical box.

A preferred embodiment, without being limited to this, provides for the realization of the system entirely with pre-connection between the elements, this pre-connection can be applied to all or part of the elements. This avoids user errors and makes system installation quicker and easier.

However, it should be understood that the distribution cable CD can be housed and axially locked inside the box 10 without the use of an input connector CE, as described, for example, in patent application BR 102016029000-7 .

Considering the characteristics of the proposed system, which allows to provide a versatile installation solution, using previously sealed branch and termination optical boxes for subsequent and simple connection of optical fibers and pre-connected optical cables, the DE input and DS output splitter devices can be previously produced in a factory environment and in accordance with the potential characteristics of the network installation to be supplied.

Thus, the present invention is advantageous once the elements of the access network (distribution boxes and optical termination boxes with embedded splitters) are arranged in the form of a busbar or sequential cascade, that is, a first element receives the optical signaling that comes from the concentrator equipment (generally, a transmission over kilometers), distributes part of this signaling to a group of nearby clients (tens or hundreds meters) and sends another part of the optical signaling to the second element of the sequence and so on, following the rules and even the limits imposed by the PON transmission technology itself.

A second differential of this solution is that, unlike other transmission technologies where complex calculations and the use of proprietary software tools are necessary to define which element / divider should be used in each location (physical) and position within a specific sequence In this case, the solution foresees the use of a busbar with fixed elements / dividers. Both the quantity of the elements in the cascade, as well as specific attributes such as division ratios and optical signal attenuations, are defined in advance by the manufacturer, and are simply installed by the Operator throughout the Operator's care region. .

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

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

Solutions with multi-fiber cables naturally have a diameter and weight much higher than those of a single-fiber solution, incurring occupancy and load (weight) greater than the posts, with direct implications on the fittings used and, in extreme cases, on the requirement of remodeling of infrastructure (change of poles).

The fourth differentiating characteristic to be highlighted is the construction of all the elements (boxes / dividers and cables of the Access network) with a pre-connectorized characteristic, that is, the Elements are supplied with factory-prepared optical connectors for quick and simple plug-and-play interconnection.

Despite the fact that only some examples of concretizations of the optical fiber termination and derivation system in question have been presented here, it should be understood that modifications of shape and arrangement of the different component parts of the system may be made, without departing from the proposed inventive concept.

Claims (15)

1. Communication and power signal distribution system in fiber optic access networks using optical boxes (10) comprising a busbar of optical boxes containing at least one optical junction box (10) connected in sequence and terminated by a termination box (12); in which at least one optical branch box (10) receives a distribution or branch cable (CD) formed by a single optical fiber that supplies a certain input optical power (A ') to the optical branch box (10 ) which has an input divider (DE) to divide, in an unbalanced manner, the input optical power (A ') received in the optical box (10) of the busbar into two parts; wherein a first part of the input optical 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 user terminal (CT) optical cables, in which a second part of the input optical power (A ') is conducted to a next optical box (10, 12) of the busbar by a continuation cable (CC) formed by a single optical fiber, and so on until reaching to the last optical termination box (12), in which the input optical power is integrally supplied to the user terminal optical cables (CT); characterized by the fact that each optical derivation box (DE) has, along the busbar, a division relation mi / ni, in which mi is the division value referring to the second predefined part of the optical power, sent to the continuation cable (CC), of the ith optical box and ni is the division value referring to the first predefined part of the optical power, sent to the termination cable (CT), of the index optical box immediately before the box to be included in the busbar; where the division ratio mi / ni of an optical junction box (DE) along the busbar is greater than or equal to the division ratio of the next box on the busbar, according to:

System according to claim 1, characterized in that it comprises and optical branch boxes (10) and an optical termination box (12), in which the number of optical branch boxes (10) is calculated according to the following inequality: TO' my 2 " psu ^ B dl U i mi) * ny - i where A 'is the input power of the first optical box of the busbar; y is the index referring to the optical box to be included in the busbar; mi is the division value referring to the second part of the optical power, sent to the continuation cable (DC), of the ith optical box; ny-i is the division value referring to the first part of the optical power, sent to the termination cable (CT), of the index optical box immediately before the box to be included in the busbar; Psu is the loss of optical power to the user; B is the loss budget (Loss budget) up to the user's optical network unit (ONU); in which, in the event that the inequality is met, the index junction optical box "y" can be included in the busbar; and otherwise, the busbar must be terminated by the optical termination box (12). 3. System according to claim 2, characterized in that the value of the loss balance B is between 30 dB and 34 dB. System according to any of claims 1 to 3, characterized in that the division ratio of the input divider (DE) of each of the optical derivation boxes (10) is between 95/05 and 55 / 45, where the numeral before the bus is the percentage of the power sent to the next optical box (10) of the system and the numeral after the bus is the percentage of the power sent to the output splitter (DS) and the optical cables user terminals (CT) (“drop”). System according to any one of claims 1 to 4, characterized in that it comprises seven branching optical boxes (10) and one termination optical box (12), in which the part of the input optical power in each optical box (10) of the network is conducted and divided, with respective unbalanced predefined optical powers of the bypass optical boxes (10) in the ratio of 90/10, 90/10, 90/10, 85/15, 80 / 20, 70/30, 60/40, being the numeral before the bar 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"). System according to any of claims 1 to 5, characterized in that the optical junction box comprises a connectorized input adapter (AE) to receive connectorized distribution cable (CD) of a predefined length with a connector of entry (CE). 7. System according to any of claims 1 to 6, characterized in that the output divider (DS) of each optical box (10, 12) is a balanced l: 4 or 1: 8 or l: l6 divider . System according to any of claims 1 to 7, characterized in that each optical box (10) comprises an output adapter (LAS) connectorized to be coupled to the output connector (C) of a continuation cable (CC) single fiber optic connectorized. 9. System according to any 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 fiber optic extension (EFO) is led to the input splitter device (DE), in which it is divided into a continuation fiber (FC) and at least one terminating fiber (FT). 10. System according to any of claims 1 to 9, characterized in that the terminating fiber (FT) is led to an output splitter device (DS) and is divided into multiple user fibers (EU), each one being selectively, by connectorization, to respective connectors (C) and output adapters (AS). System according to any one of claims 1 to 10, characterized in that each branch optical box (10) comprises a continuation fiber (FC) containing the second part of the input optical power in the box optics (10), in the that the continuation fiber (FC) is provided with an output connector (CS) for coupling to an output adapter (AS) arranged in a respective opening of the box (10). System according to any of claims 1 to 11, characterized in that outlet adapters (AS) are arranged in openings located in the cover (20), for connection with user terminal optical cables (CT). System according to any of claims 1 to 12, characterized in that each branch box (10) of the network comprises: a first box part (10A), in which an optical signal that is transmitted by the optical distribution cable (CD) or continuation (CC) is received and divided and transmitted in an optical cable bypass terminal (CDT) and on an optical continuation (DC) cable; and a second box part (10B) in which the optical signal that is transmitted by the terminal branch optical cable (CDT) is received and divided and transmitted in multiple optical fibers, with respective optical powers to be transferred, by connectorization, to respective user terminal (CT) optical cables. System according to claim 13, characterized in that the second box part (10B) is separated from the first box part (10A) and is connected to it by the terminal drop cable (CDT) . 15. Power and communication signal distribution system in fiber optic access networks using optical boxes (10) comprising a busbar of optical boxes containing seven branching optical boxes (10) connected in sequence and terminated by a junction box. termination (12); in which the optical bypass boxes (10) house a distribution or bypass cable (CD) formed by a single optical fiber that supplies a certain input optical power (A '), each of the optical bypass boxes presenting (10) an input divider (DE) to divide, in an unbalanced manner, the input optical power (A ') received in the optical boxes (10) of the busbar into two parts; in which a first part of the input optical power (A ') is conducted towards 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 user optical terminal (CT) cables, in which a second part of the input optical power (A ') is conducted to a next optical box (10, 12) of the busbar by a continuation cable (CC) formed by a single optical fiber, and so on until reaching to the last optical termination box (12), in which the input optical power is integrally supplied to the user optical terminal (CT) cables; characterized by the fact that the part of the input optical power in each optical box (10) of the network, is conducted, and divided, with respective unbalanced optical powers of the bypass optical boxes (10) in the proportion 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 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”).