Optical Line Protection Manufacturer

HYD TECHNOLOGY regards technological innovation as the basis for the survival and development of the enterprise, and pays great attention to maintaining the advantages of OLP technology. It has perfect network management functions at the carrier level and is an ideal partner for broadband access and optical fiber transmission.

Custom Your Optical Line Protection System With Professional Manufacturer

The optical line protection equipment is a protection system developed by HYD TECHNOLOGY for optical fiber line backup.It adopts an advanced optical path automatic switching module.

The signal state of the optical path can be switched instantaneously to ensure that the protection system operates normally when the main optical cable has a total resistance obstacle, and the service quality of the operator is improved.
OLP is widely used in the main and backup protection of various main lines and various optical path switching networks.
Its advantage is that the optical signal can be directly converted and utilized in the optical line, and it is small in size, economical and safe, so it is used in many optical transmission fields.

Intelligent optical BYPASS optical protection by HYD TECHNOLOGY ,is mainly used to protect the gateway equipment connected in series in the network from becoming a single point of failure due to accidental failure, or to provide favorable assistance when these gateway equipment are upgraded and maintained, avoiding the time delay and network failure caused by manual network switching.

Operation and maintenance management is difficult, and it is an indispensable solution for high-availability operation guarantee of the network.


  • OLP – Optical Line Protection

The design idea of HYD TECHNOLOGY OLP (Optical Line Protection)is to use an automated system to complete the daily monitoring of operation and maintenance personnel and manual scheduling when a failure occurs

OLP(Optical Line Protection) technology completes routing switching operations at the optical layer. Optical layer protection has incomparable advantages over upper layer service protection, such as high reliability, fast speed, and low cost of optical layer restoration;


  • Optical Bypass Protection

The OBP optical bypass protection system is an intelligent switching system that is applied in the field of optical fiber communication and can automatically bypass faulty network nodes.

It can automatically identify the power supply status of network nodes and the output status of optical signals. It can avoid disconnection of SDH network at network nodes and maintain overall network connectivity.

● Diverse heartbeat modes
● High integration and high reliability design
● Support visual master control configuration management
● Low insertion loss, high stability instantaneous switching
● Transparent transmission for optical physical links
● Support SNMP, Web, Client network management

  • Optical Selective System

OLP (Optical Line Protection)can provide protection for different network types (SDH, WDM, PTN, etc.), the equipment is independent and transparent to the transmission signal, and there is no compatibility problem;

When OLP(Optical Line Protection) is connected to the transmission system, except for the insertion loss introduced by the equipment, it will hardly affect other transmission characteristics.

  • DVOA – Dynamic Variable Optical Attenuator

The optical line protection system is the best solution to provide users with uninterrupted communication, and it is the guarantee for the security service commitment provided by the operation and maintenance department. An optical communication network with blocking, high reliability, security, and strong disaster resistance.

Comparison of various olp protection methods

1:1 Optical Line Protection

1:1 type OLP (Optical Line Protection)protection switching equipment adopts the method of selective transmission and selective reception “choose one of them as the sending end and receiving end”, that is, the service light sent by the Tx port of the transmission device is all transmitted through the OLP device through the main route ( The pink line in the figure below).
A laser is mounted on the OLP single disk, which stably and continuously emits a light source of a specific wavelength to the backup route (the black line in the figure below), and monitors the indicators of the backup route in real time, and the laser is also a 1:1 type protection switching device at the hardware level. An important component of protection switching protocol transport.

When an OLP 1:1 device detects a line fault, it needs to communicate with the peer device to make a judgment, and the devices at both ends switch together to ensure the switching of the entire line and service transmission. 1:1 protection, the backup route sends test light from the module in the optical protection, and keeps the backup optical path in a smooth state.

1+1 Protection Switching Principle

The 1+1 protection mode is a dual transmission and selective reception method (two channels of transmission only need one channel of reception), that is, after the light emitted by the T port of the transmission device passes through the OLP(Optical Line Protection) device, the service light of the transmission device is divided into 50% of the equal 2 channels are used as business light, transmitted on the main route (pink line in the figure below), and 50% are used as test light, transmitted on the backup route (black line in the figure below), used to check the indicators of the backup route real time monitoring.
As shown below:

When an OLP(Optical Line Protection) 1+1 device detects a line fault, only one end of the device needs to be switched to switch over the entire line without affecting service transmission.
It is not necessary to make a judgment after the communication between the devices at both ends, whether to switch the line.

Passive Optical Line Protection

Passive OLP optical line protection equipment is an exclusive patented product of Guangzhou Visint Communications. This product is used for the protection system of optical fiber line backup. It adopts advanced and unique passive optical devices and technologies without using optical switches and power supplies. It is an optical device product that can be used in the outdoor (field) environment to switch between the main and backup optical paths.

Application location of OLP(Optical Line Protection) equipment

1) OLP (Optical Line Protection)is configured in front of the outbound optical fiber at each site to protect the line optical fiber

2) The main and standby routes should be separated at the physical level, that is, the main and standby routes are different optical cables, and the main and standby optical cables do not pass through the same pipeline

  • The transmission parameters (attenuation and dispersion) of the backup route should be as close as possible to the indicators of the main route. For high-speed communication systems and DWDM systems where there are differences in attenuation and dispersion between the main and backup routes, EDFA and DCM should be considered, and OSC should also be considered Handling of monitoring channels

OLP(Optical Line Protection) network management system

The functions of the network management system are mainly maintenance management and active switching scheduling

Real-time monitoring: realize real-time monitoring of single-disk optical power and routing line status of switching equipment Alarm management: real-time alarm collection, alarm and confirmation of switching equipment

Performance management: collect data on equipment running status at intervals set by the user, and

Query historical data

Security management: user and its authority management

Log management: record system events e

Topology display: Realize topology display of device distribution and status

OLP(Optical Line Protection) centralized network management solution

Through DCN/DNN network

HYD TECHNOLOGY Optical Line Protection

The network management information of each sub-node OLP(Optical Line Protection) device is uplinked to the DCN/DNN network through the Ethernet electrical port or SFP optical port of the main control panel and transmitted to the central computer room. The network management server in the central computer room is installed with our NetRiver network management system. Centralized network management of equipment;

Through the E1 transmission network

HYD TECHNOLOGY Optical Line Protection

Each sub-node is equipped with a protocol converter (Ethernet to E1), which is used to connect with the Ethernet electrical port of the main control panel of the OLP(Optical Line Protection) equipment, converts the network management information of the OLP equipment from Ethernet signals to E1 signals, and connects to the E1 transmission network The central computer room is also equipped with a protocol converter (E1 to Ethernet), and then the network management information is converted from E1 signal to Ethernet signal and connected to the network management server. Through our NetRiver network management system, all devices can be centrally managed

DWDM system OLP (Optical Line Protection)protection scheme

HYD TECHNOLOGY Optical Line Protection

Design principles when DWDM system introduces OLP(Optical Line Protection) 1

  1. Line optical power design

The introduction of OLP equipment will only increase the attenuation on the line, so it is necessary to recalculate the optical power budget to ensure that the output of the optical amplifier at the receiving end reaches the nominal value.

Design principles when DWDM system enters OLP 2

  1. Signal-to-noise ratio

If the optical amplifier configuration needs to be changed, or although the optical amplifier configuration remains unchanged, the input optical power of the optical amplifier design at the transmitting end is reduced, which will affect the signal-to-noise ratio at the receiving end. When the design signal-to-noise ratio cannot meet the standard, it is necessary to further consider optimizing the optical amplifier configuration (even adding optical amplifier stations, etc.).

  1. Dispersion compensation

The main route usually maintains the original dispersion compensation configuration, and the dispersion of the backup route must be similar to that of the main route to meet the requirements of the system window.

Design principles when DWDM system introduces OLP 3

  1. OSNR and DCM verification in multi-span scenarios

When there are multiple sections of protection on the line (as shown in the figure below), and the protection switching time of multiple fiber cuts is required to be less than 50 ms, it is necessary to verify that the system OSNR and residual dispersion of all active and standby fiber combinations meet the requirements of the system dispersion window.

1) For a 10G rate system, all combinations need to be verified.

2) For the 40G rate system, only one fiber cut protection (less than 50ms) is supported, and there is no need to verify all scene combinations


OLP optical line protection has doubled the demand for local network fiber resources, requiring the parameters of the main and backup lines to be the same as much as possible. 

The insertion loss caused by adding more optical switches will shorten the distance of the optical multiplexing section. If the length of the main and backup routing lines is different Too large, the fiber type is inconsistent, and the configuration of the main and standby routing optical amplifiers and dispersion compensation modules is more complicated. 

It should be noted that different physical routes should be selected for the main and standby optical cable resources, otherwise the OLP equipment will not be protected after the entire optical cable is interrupted effect.

According to the length of the main and backup routing lines, OLP application scenarios can be divided into three types:

Scenario 1: Add OLP equipment directly in the middle of SDH or WDM system. The scenario of this application is relatively simple, “the length of the main routing fiber and the backup routing fiber are required to be equal”, “the attenuation of the parallel I optical path must have at least 3dB margin “. 

Because adding OLP will cause 3dB attenuation, if the system does not have such a large attenuation capacity, adding OLP equipment may cause code errors, alarms, and even interruptions in SDH or WDM equipment. When designing the system, it is necessary to do a good job in research and testing.

Scenario 2: When introducing the OLP system, in order to play a protective role, it should be considered in combination with dispersion and optical power compensation. 

If “the main and backup routing optical cable models and optical cable lengths are not consistent”, it is necessary to compensate for the existing dispersion capacity difference. , 

the standby route will be configured with the corresponding dispersion compensation module, when “the standby attenuation minus the active attenuation is greater than or equal to 3dB, less than or equal to 12dB”, it is necessary to configure power pre-amplification compensation on the standby line”

Scenario 3: An EDFA optical amplifier station needs to be added to the backup route of the OLP system. When the length of the backup optical cable is far greater than the length of the main optical cable and the attenuation is greater than 10dB, a relay amplifier unit ( EDFA)

1000 series protection products are used in the optical line for protection purposes, developed and designed by HYD Technology. They can solve many issues of transmission lines like power failure, board failure, and instability in the existing network. 

Application 1: Optical Line Protection(OLP) Solution

To protect the optical line, an OLP protection solution is used, and to achieve this, the OLP is to be added on the two ends of the transmission simultaneously. Main and standby should have different routing lines, and using the amplification and dispersion compensation module helps adopt these lines. 

It also helps to support the durable fiber bidirectional, transparent transmission, and single fiber bidirectional. It also offers a backup fiber monitoring function and quick switching optical lines. 

The OLP-1+1 Optical Line Protection Unit is a specialized device used in optical communication networks to ensure uninterrupted communication.
It separates the incoming optical signal and sends it to both the main and backup channels.
At the receiving end, it selects the working channel or the backup channel for protection. If a fault occurs in the working channel, it swiftly switches to the backup channel within 15ms, guaranteeing continuous communication.
This equipment is designed for industrial-grade performance, providing reliable operation even in harsh environments.
It finds wide application in various optical networks, such as PDH, SDH, C/DWDM systems, power communication networks, CATV networks, and more.

Application 2: Optical Bypass Protection(OBP) Solution

OBP is a bypass solution that offers bypass protection to either bypass a single site or help bypass the single device failure. It helps maintain the network’s connectivity and also offers a bypass time of less than 25 ms in case of failure. It offers a quick bypass if any problem arises, like power or equipment failure.

Intelligent Optical BYPASS protection is primarily utilized to safeguard network gateway devices from becoming single points of failure due to unexpected faults.
It also offers valuable assistance during upgrades and maintenance of these gateway devices, preventing delays caused by manual network switching and easing network operation and management challenges.
This solution is indispensable for ensuring high network availability and reliability.


Optical line protection is a technique used in optical communication networks to ensure the reliability and continuity of data transmission. It involves setting up redundant optical paths, known as protection paths, alongside the primary optical path, known as the working path. The purpose of optical line protection is to quickly switch the data traffic from the working path to the protection path in the event of a failure or disruption in the network.

The protection paths are typically established using optical fibers that follow a different physical route than the working path. This ensures that if there is a fiber cut, equipment failure, or any other issue along the working path, the protection path can be activated to maintain uninterrupted data transmission.

There are different methods of optical line protection, such as 1+1 protection and 1:N protection. In 1+1 protection, the working path is duplicated by a fully redundant protection path. The data is simultaneously transmitted over both paths, and the receiver selects the stronger signal. If the working path fails, the receiver automatically switches to the protection path without any interruption in the data flow.

In 1:N protection, multiple working paths are protected by a shared protection path. This method is more cost-effective as it allows several working paths to share a single protection path. If any of the working paths fail, the protection path can be dynamically assigned to the affected working path to maintain data transmission.

Optical line protection is crucial for ensuring the reliability and availability of optical communication networks. It helps prevent service disruptions and downtime by quickly redirecting data traffic to alternate paths in case of network failures. This ensures that critical data, such as voice, video, and data signals, can be continuously transmitted without interruption.

Overall, optical line protection is an important component of network design, providing a robust and resilient infrastructure for reliable data transmission in optical communication networks.

Optical fiber communication works by sending information using light signals that travel through special thin strands called optical fibers.
Optical fibers are thin, flexible strands made of high-quality glass or plastic materials that have the ability to guide light along their length.

The principle relies on the concept of total internal reflection. When light enters an optical fiber, it is trapped and guided along the fiber through a process called total internal reflection.
Total internal reflection occurs when the light ray traveling inside the fiber encounters the boundary between the fiber core and the surrounding material, known as the cladding, at an angle greater than the critical angle.

The core of an optical fiber is designed to have a higher refractive index than the cladding, which helps to confine the light within the fiber and maintain its propagation. This ensures that the light signal can travel long distances without significant loss or degradation.

To transmit information through the optical fiber, the light signal is modulated with the data to be transmitted.
To send information through the optical fiber, different methods like changing the brightness, phase, or frequency of the light signal can be used.
The modulated light signal carries the encoded information in the form of variations in its intensity, phase, or frequency.

Once the modulated light signal travels all the way to the end of the optical fiber, there is a special device waiting to catch it. This device, called a light-sensitive detector, is like a small electronic eye that can sense the light. It captures the light and prepares it for further processing.
The detector changes the light signal back into an electrical signal, which can be understood and used to get the original information that was sent.

The principle of optical fiber communication offers several advantages over traditional electrical communication systems. Optical fibers have a special ability to carry a lot of information and send it over really long distances without losing much quality along the way.
They are also immune to electromagnetic interference and can support high-speed data transmission rates.

In summary, the principle of optical fiber communication involves guiding light signals through optical fibers using total internal reflection. Modulating the light signals with data allows for the transmission of information, which is then detected and converted back into electrical signals at the receiving end.

Why Choose HYD TECHNOLOGY to Support You OLP 0ptical Line Protection

HYD TECHNOLOGY always custom OLP solution for your project ,and in our OLP Optical Line Protection we have below advantages :

1. Independent intellectual property rights, strong research and development strength;

2.HYD TECHNOLOGY has become one of the domestic suppliers with a relatively complete series of similar products, which can solve most OLP application requirements of user transmission systems including data access, with flexible configuration;

3. The whole line of products supports the network management function, and the network management supports remote transparent transmission, which is convenient for users to manage and configure;

4. Perfect production line, strict process flow, testing environment, complete equipment, quality assurance;

5. Our product faces users and can quickly develop new products that meet customer needs;


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Active and standby route monitoring function OLP

It can monitor the line insertion loss of the main and backup routes in real time, and give an alarm prompt according to the set alarm threshold, effectively avoiding the possibility that the fibers of the main and backup routes are blocked at the same time

Automatic optical line protection switch switching protection

The main route fiber is blocked, and it will automatically switch to the backup route within 50ms to ensure that the business is not blocked

Maintenance scheduling function

When the optical fiber of the main route is normal, the network management or the equipment panel can issue an instruction to schedule and switch the working route to ensure uninterrupted communication services

Power-off, power-on optical circuit maintenance (

Power-off or power-on of the switching panel does not affect the working line status, ensuring the normal operation of the system and having hot-swap function

Professional Provider of Optical Line Protection System -HYD TECHNOLOGY

The widespread application of large-capacity and long-distance optical fiber transmission systems provides reliable transmission channels for various business networks.

However, once the optical fiber line is cut off or the equipment fails, it will cause very serious impact.

Therefore, how to better ensure the security of transmission lines is very important in the construction of optical communication networks.

The OLP technology provides a practical and reliable solution for the safe and smooth transmission network, and has a very broad application prospect.

In order to effectively realize the protection at the line level of the optical cable and improve the anti-blocking strength and reliability of the optical fiber communication, the introduction of the OLP protection system is an effective solution.

Selective transmission and selective reception type OLP system switching, recovery speed is fast, and the introduction loss is small, which is suitable for optical fiber protection in many occasions.

For OLP design, important parameters such as switching delay and insertion loss should be fully considered to ensure the reliability of optical path switching, meet the principles of scalability and applicability, and carry out construction design according to the connection methods of different devices.


Insertion loss is one of the important indicators to evaluate the performance of O LP system, that is, the additional loss caused by the system connected to O LP equipment.

The working principle of OLP is: when the transmission of the working link is interrupted or the performance deteriorates to a certain degree, the system will automatically switch over, and switch the service signal on the main fiber to the backup fiber for transmission.

Due to the increase and decrease of the number of wavelengths in the wavelength division system; there is an erbium-doped fiber amplifier EDFA cascade in the longer line, and the blockage of a certain section of fiber will cause all optical amplifier sections to be shut down. Therefore, it is very necessary to use the OLP system .

Our customization services in Optical Line Protection ensure we can create something just right for you.

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