8.1 ODF is included in the PON exchange section. ODF must have the following capabilities:

− providing free access to any of the optical ports and the ability to quickly perform cross-connection work;

− increasing the cross-connection capacity during operation;

− ensuring prompt production of installation, installation and switching of OV;

− system for laying fiber optics and patch cords, guaranteeing compliance with the requirements for the bending geometry of fiber optics;

− constructively support the installation of splitters directly in the ODF;

− occupy a minimum area.

The cross must match " Technical requirements to high-density station optical cross-connections”, approved by the Chief Technical Director of Kazakhtelecom JSC.

Basic principle of high density ODF installation modular design consists of cutting the optical station and line cables (fibers) supplied to the cross-connect onto the mounting modular tubes, through the adapter devices shown in Figure 19.

Figure 19 Figure 20

Mounting modular tubes with 12 or 16 optical fibers are fed to the splicing and switching module shown in Figure 20, where the fibers are boiled into factory-prepared picktails. Welded fiber joints reinforced with KDZS sleeves are placed in cassettes. Design optical cross should ensure the extension of the splicing and switching module from modular blocks to a length of up to 1.5 meters due to the supply of mounting modular tubes laid in the switching and splicing fiber module, only when installing (unbonding) optical fibers of station and linear fiber optics. SC/APC type connecting sockets are installed in special sockets of patch panels.

8.2 Due to the large number of optical distributions of various designs, including top or bottom feed of the fiber optic cable from a cable rack or through a raised floor, a detailed description of the installation is not advisable; in each specific case, the manufacturer’s instructions should be used. The length of the supply of linear cable fibers and picktails left on the cassette in the terminal device must be at least 0.5 m, and the length of the fiber supply left on the cable rack or in the raised floor is at least 2 m. Placement options are shown in Appendix 3.

NOTE For any optical cross-connect design, station cables or station patch cords must be fed to station splicing and switching modules installed in the upper part of the cabinet, in the middle part of the cabinet it is necessary to install splitter modules with input and output splitters welded into connectors (optical switching ports), and onto linear modules installed in the lower part of the cabinet, it is necessary to supply main linear fiber optic cables. There are 2 options for mounting (feeding) OLT linear terminations to the optical cross-connect:

When installing an OLT in a combined room in close proximity to the ODF and the capacity of a GPON network node for up to 2 thousand subscribers, the OLT outputs can be connected directly to the ODF trunk ports using patch cords of the appropriate length;

When installing an OLT in a containment zone and the capacity of a GPON network node exceeds 2 thousand subscribers, the connection of the OLT outputs to the ODF station ports must be carried out using 3-meter pigtails terminated on the OLT side with 48-96 station cables, and on the ODF side the station cable must be inserted and welded into station splicing and switching modules. In the latter option, switching of OLT outputs with any port of a linear trunk cable should be carried out using short patch cords inside the ODF rack between the linear and station ports of the optical cross-connect.

8.3 Inside the premises of the telephone exchange, up to the terminal cable equipment ODF should be laid OK with a non-flammable sheath. The margin for cutting the optical station cable from the station and linear parts of the cross-connect must be at least 3-3 meters.

An optical cross-connector is a device specially designed for detachable, convenient connection of optical cords and multi-fiber cables, which is carried out using sockets.

There are two types of crosses:

• wall crosses - mounted on walls. Available with 16...72 ports, designs with a large number ports (multiples of 16). This type of crosses has both lower and top position cable entries;
• rack cross-counters - installed directly in cabinets. Represent metal box, the back of which is equipped with cable entries, and the front has sockets specially designed for optical sockets. Series of rack crosses differ from the nominal number of floors, which is measured in units.

The design of the optical crossover is a metal box that can be disassembled. The front surface will contain places where you can attach sockets (optical adapters). Inside the cross itself there is a place where you should attach optical cassettes with special grooves designed for fixing sleeve kits to protect the joints. When installing an optical cross-connect, the sleeves must reliably protect the welding points.

The design of the optical cross itself allows you to place excess length in the box fiber optic cable. This ensures the required bending radius, which corresponds to certain technical specifications on the use of this type of cable. The rear part of the structure is equipped with elements for rigidly attaching the optical cable to the cross-connect. There are also required holes for fastening inside the optical fiber cross-connect.

Rack crosses: design features

A common type of optical products for communication is optical rack-mount cross-connects (abbreviation KRS). These designs are used to modularly fill server racks and are not used as separate switching units.

This type of crossover is a durable metal box with connectors and special inputs designed for optical cables. The cross can accommodate from 2 to 8 cables, switching can occur from 8 to 48 ports.

Rack crosses have standard universal sizes, manufacturers create convenient modern fastenings and thoughtful equipment for them.

Design features also include:

• the ability to place from 8 to 144 different adapters and connect any type of cable;
• durable steel body, which is necessarily covered with a layer of protective paint;
• compliance by manufacturers with relevant quality standards for such equipment under strict control, which reduces the presence of defects in such structures to a minimum;
• Rack-mount crosses can be installed inside closed cabinet and inside the rack.

KRS cross-countries may differ in the number of adapters, design features, and the number of connectors.

There are simple block crosses with universal standard height(unit U), a multiple of 44.45 mm, as well as crosses with retractable panels and side fastenings that are convenient when carrying out installation work. The height of the products is determined simply, since the width of the design contains eight adapters, while the number of ports in the cross-connect can vary from 8 to 144.

It is important! The depth of the crossover is not technically regulated, which allows manufacturers to offer their own options.

Optical connectors are used only in indoors, however, for some operating conditions, the use of waterproof and dustproof housings is recommended.

Installation of the fiber optic system is carried out by specialists who must strictly follow the list of rules and safety standards.

When carrying out installation work, you should take into account following features and settings:

• it is necessary to leave gaps between the housings during installation rack crosses. This is done for convenience during future maintenance;
• if the cable does not have connections, then switching inside the optical cross-connect is carried out using pigtails;
• if it is necessary to change panels, it is possible to choose an option with suitable adapters; the panel is changed using special latches.

About the demand for optical cross connects

On this moment Consumers give preference to convenience when installing cross-connects, which is why sales of rack-mounted retractable cross-connects, which are equipped with shelves for cable spare parts, are increasing. It is also convenient to work with pre-assembled cross-connects for welding; this simplifies the task of installing fiber optic equipment at the assembly site.

Cable television services give preference to reliable, vandal-proof designs with locks that will protect equipment from burglary and damage. Dust- and moisture-proof crosses are relevant when used in industrial automatic systems.

Universal designs began to appear that can be used in both rack and wall-mounted versions. There are also ultra-small cross-connects that are used for mounting small LANs, as well as cross-connects with high-density panels.

Features of choosing optical connectors:

• An inexpensive cross is difficult to maintain in the future. Difficulties may arise during the assembly process if the customer wants to replace, for example, the lower pigtails. Therefore, it is better to buy high-quality optical connectors for certain parameters;
• the product must be certified, have the appropriate licenses, best of all, international standard. Foreign partners and well-known Russian manufacturing companies strictly comply with warranty obligations in the event of failure of optical cross-connects;
• most best option- ordering pre-assembled cross-connections, this saves time and allows you to achieve appropriate quality during installation;
• The documentation for the cross must be complete. The passport of the optical crossover must contain not only data on technical and performance characteristics ah, but also complete legal address manufacturer, license and certificate numbers, stamps of the relevant control services.

Working with fiber optic equipment requires highly qualified specialists and expensive equipment. Contact companies that actually install optical crossbars on professional level and have extensive experience in this type of work.

Optical cross connectors are used to enter the optical cable and connect station equipment to the line. To implement the project construction of fiber-optic communication lines you need to select the brand and capacity of the optical cross-connect. For the end points of the designed fiber-optic line at Zhetygen station and Korgas station, required amount There are 16 sockets in the cross. At the intermediate points Kurozek station and Shelek station, where two cables are installed, 32 sockets are needed. These requirements are met by optical cross-connectors of the PR-16 type produced by JSC 2ASystem, Tula. One cross-connect is installed at the end points, two at intermediate points (sides A and B), a total of 6 optical cross-connects are required.

Since optical pigtails are ordered separately, we will choose standard pigtails 1 m long. with FS type connectors (accordingly, the optical cross-connector will also be equipped with FS type connectors).

Optical cross (Fiber Cross) Distribution panel PR 16

General information.

Optical cross (Fiber Cross) distribution panel PR 16 provides:

• - Input, placement, fastening and storage of stock of station and line cables;
• - End seal, connection, switching of line and station cables with optical fibers in a public communication network, in technological communication networks and special-purpose communication networks;
• - Connection of control and measuring equipment;
• - Possibility of marking linear and station circuits.

Technical characteristics of the optical crossover.

The maximum number of incoming linear fiber optic cables is 4 pcs.

The maximum number of optical connecting sockets on the panel is 16 pcs.

Overall dimensions of the Optical cross (Fiber Cross) PR 16 - 484 x 280 x 44mm

The weight of the Fiber Cross distribution panel PR 16 is 2.4 kg.

Type of optical ports - FC, SC, ST, FC/APC, SC/APC

Optical crossover delivery set.

Optical cross (Fiber Cross) distribution panel PR 16 is equipped according to table 3.3

Table 3.3 - Optical crossover delivery set

	Name	Quantity, pcs.
	Distribution panel
	Splice plate
	Screw-washer-nut set	1 (supplied by agreement)
	Screed 80mm
	Screed 140mm
	Organizer platforms
		By number of ports
	Passport products

Notes

It is allowed to replace the products included in the delivery set with similar others that do not impair the presentation, performance characteristics and comply with safety requirements.

Delivered as agreed with the customer

Optical crossover safety requirements.

Before starting work, carefully study this passport.

The optical cross-connect must be used in accordance with the purpose specified in the passport.

Optical cross device (Fiber Cross) PR 16.

The optical cross is a metal box painted using powder coating technology, which ensures reliable protection from external influences. Inside the optical cross there is a splice cassette (splice plate) for laying sleeves and a supply of fibers (it is possible to place 24 fibers on one splice cassette)

The optical cross-connect has four holes for optical cable input/output. The holes are closed with rubber plugs for protection. internal space optical cross from dust; when installing an optical cable (OK) in PR 16, you can select one of four holes for OK input (or use all four if necessary).

Installation instructions for optical cross (Fiber Cross) PR 16

Removing the packaging - be careful not to damage the optical cross-connect with the tool. After opening the package, check external condition assembly units and parts of the optical crossover, as well as the availability of all accessories according to the packing list.

Preparation for installation

Before you begin installing the OK, make sure that the mounting brackets on the right and left sides of the optical cross-connect are firmly secured;

Place the Fiber Cross PR 16 on the desktop for mounting OK.

Figure 3.10 - General form distribution panel Fiber Cross PR 16 (pictured without top cover with FC connectors).

Cable cutting and entry

Cut the cable in accordance with Figure 6.14.

Insert the cable into the Fiber Cross PR 16 through the hole, cutting the rubber membrane.

Secure the OK using the ties included in the kit. Secure the central power element using a bracket and screws as shown in Figure 3.12.

Place heat shrink sleeves onto the pigtails.

Figure 3.12 - Optical cable input

Works with optical fiber.

Strip fibers and weld in accordance with the recommendations for the welding equipment used;

Number the modules of the cable being installed;

Number the pigtails and weld them with the corresponding fibers;

Bake heat-shrinkable sleeves (heat-shrinkable sleeves are included);

Place the sleeves and fiber stocks in the cassette according to Figure 3.14, 3.15. (drawings of cable module insertion and pigtail placement are spaced for ease of reading).

When laying stocks of cable fibers, sleeves and pigtails, ensure that the bending radius of the fibers and pigtails does not exceed 30 mm

Close the splice cassette with a transparent lid.

Connect the pigtails to the adapters according to their numbers.

Figure 3.13 - Input of cable modules

Figure 3.14 - Layout of pigtails

Rack mounting.

The optical cross (Fiber Cross) distribution panel PR 16 is secured in a 19-inch rack with four M 6 screws (fastening screws are not included in the delivery package). Place and secure the cable supply in convenient location.

To assess the quality of installation of the optical cross-connect, reflectograms of each OF in the regeneration section are taken. If optical attenuation is normal and there are no defects in the welded joints, the station equipment is connected to the line using patch cords.

Table 3.4 - Organization of jumpers on the optical cross-connect of the Kurozek station access node

At all communication points on optical cross-connections, 1-4 optical fibers are switched to Huawei OptiX OSN 1500B equipment. A linear path is organized along 1-2 OBs for the operation of a digital transmission system; 3-4 OBs are also connected to digital equipment and are used for automatic reservation of the linear path.

An optical cross-connect is a passive optical device for connecting multi-core optical cables with single-fiber optical cords with optical plugs (connectors) at the ends. Optical cross connects are used for connection cable network with active network equipment and transmitting an optical signal from the active equipment to the network.
Optical cross connects come in various modifications and are divided into:

For correct installation optical cross-connects they are equipped with:

splice cassette;

splice plates;

KDZS sleeves;

pigtails;

adapters;

set fastening elements(ties, bolts, clamps, lugs, marking stickers).

At first glance, installation of an optical crossover may seem simple process, but in fact this is not entirely true. Assembling the optical cross is enough important point in the construction of a distribution network. In case of incorrect and careless installation, the signal may not pass through at all due to high attenuation in places where fibers are welded or in places where pigtails are laid and cable fibers are stored in splice plates or in cross-connects. Also, attenuation or breakage of fibers can be due to improperly fastened cable in the cross-connect or improper placement of sleeves in the cassette holders.
Installation of the optical cross-connect must be carried out by a certified experienced specialist at all necessary equipment and a tool.

It is important to know! When installing an optical cross-connect, there should be no figure-of-eights of pigtail fibers in the cassettes, and there should be no excess supply of fibers that interferes with installation. After installing and fastening the pigtails into the adapters, the adapters on the other side must be plugged to avoid dust and debris getting into the joint. After installing the cross-connects, it is necessary to illuminate the fibers for compliance with the circuit.

Navikom specialists have everything necessary for the prompt installation and restoration of optical cross-connections.