Category Archives: Network Media Coversion

Network Media Converter Tutorial

Media converters is usually involved in all types of networks to implement and optimize fiber links. For example, it can be deployed in local area network (LAN) to integrate fiber optic cabling and active equipment into existing copper-based, structured cabling systems while achieving significant cost-savings. Moreover, media converter also plays a significant role in today’s multi-protocol, mixed media network. It has become a flexible and cost-effective networking devices. This article will mainly explain the benefits concerning media converter, as well as its common types and applications.

Currently, the most used media converter is a device that functions as transceiver, converting the electrical signal used in copper unshielded twisted pair (UTP) network cabling into light waves used in fiber optic cabling. Media converter is rather essential when fiber optic connectivity is required. This happens when the distance between two network devices exceeds the transmission distance of copper cabling. Media converters enables two network devices with copper ports to be connected over extended distances via fiber optic cabling.

In addition to copper-to-fiber conversion, media converters also provide fiber-to-fiber conversion from multimode fiber to single-mode fiber, and convert a dual fiber link to single fiber using bi-directional (BIDI) data flow. Media converters can also convert between wavelengths for wavelength division multiplexing (WDM) applications.

fiber media converter

Benefits of Media Conversion Technology

The ever-increasing demand for higher bandwidth and longer distance transmission has made media converter even more important. By allowing the use of fiber when it is needed, and integrating new equipment into existing cabling infrastructure. Media converters provide seamless integration of copper and fiber, and different fiber types in enterprise LAN networks. They support a wide variety of protocols, data rates and media types to create a more reliable and cost-effective network.

Media converter helps to increase network distances by converting UTP to fiber thus to extend fiber links for longer distance data transmission. Which may contribute a lot to maintain investments in existing equipment. Moreover, media converter can also increase the capacity of existing fiber with WDM wavelength when used with multiplexers.

Types of Media Converters

There are a wide range of copper-to-fiber and fiber-to-fiber media converters available that support different network protocols, data rates, cabling and connector types. In this part, we will mainly introduce some of the most commonly used media converters.

Ethernet Copper-to-Fiber Media Converters

Supporting the IEEE 802.3 standard, Ethernet copper-to-fiber media converters provide connectivity for Ethernet, Fast Ethernet, Gigabit and 10 Gigabit Ethernet devices. Some converters support 10/100 or 10/100/1000 rate switching, enabling the integration of equipment of different data rates and interface types into one seamless network.

Point-to-Point Applications

A pair of media converters can be used in point-to-point connections that connect two UTP Ethernet switches (or routers, servers, hubs, etc.) via fiber, or to connect UTP devices to workstations and file servers.

point-to-point applications

Campus Fiber Application

In this application example, 10/100 media converters are installed in a redundant power chassis for high-density fiber distribution from UTP switch equipment (A) at the network core. A UTP workgroup switch (B) is connected via fiber to the network core with a standalone 10/100 media converter. Another 10/100 converter enables fiber connectivity to a PC UTP port in a fiber-to-desktop application (C). An Ethernet switch (D) is connected directly via fiber to the media converter module at the network core.

campus fiber application

Serial-to-Fiber Media Converters

Serial-to-fiber converters provide fiber extension for serial protocol copper connections. They can automatically detect the signal baud rate of the connected full-duplex serial device, and support point-to-point and multi-point configurations.

RS-232 Application

RS-232 fiber converters can operate as asynchronous devices, support speeds up to 921,600 baud, and support a wide variety of hardware flow control signals to enable seamless connectivity with most serial devices. In this example, a pair of RS-232 converters provides the serial connection between a PC and terminal server allowing access to multiple data devices via fiber.

RS-232 application

RS-485 Application

In this application, a pair of RS-485 converters provides the multi-drop connection between the host equipment and the connected multi-drop devices via fiber.

RS-485 application

Fiber-to-Fiber Media Converters

Fiber-to-fiber media converters can provide connectivity between multimode (MM) and single-mode (SM) fiber, between different “power” fiber sources and between dual fiber and single-fiber. In addition, they support conversion from one wavelength to another. Fiber-to-fiber media converters are normally protocol independent and available for Ethernet, and TDM applications.

Multimode to Single-mode Fiber Conversion

Enterprise networks often require conversion from MM to SM fiber, which supports longer distances than MM fiber. Mode conversion is typically required when:

  • Lower cost legacy equipment uses MM ports, and connectivity is required to SM equipment,
  • A building has MM equipment, while the connection to the service provider is SM,
  • MM equipment is in a campus building and SM fiber is used between buildings.

MM-SM fiber conversion

Dual Fiber to Single-Fiber Conversion

Enterprise networks may also require conversion between dual and single-fiber, depending on the type of equipment and the fiber installed in the facility. Single-fiber is single-mode and operates with bi-directional wavelengths, often referred to as BIDI. Typically BIDI single-fiber uses 1310nm and 1550nm wavelengths over the same fiber strand in opposite directions. The development of bi-directional wavelengths over the same fiber strand was the precursor to wavelength division multiplexing.

dual fiber to single fiber conversion

Conclusion

Simple and robust in design yet cost-effective to deploy, media converters are the best solution for the rapidly growing demand of new networking applications. Besides, they bridge the existing bandwidth gap between the LAN and service provider fiber optic backbone.

What Is Fiber Optic Loss?

Fiber optic transmission has become the backbone of networking in the majority of companies nowadays. Serving as the trend of data transmission in this information age, it does obtain some advantages when comparing with other transmission medium like copper. With lighter weight, smaller size and more flexibility, fiber optic enables data to transmit at a higher speed and over longer distances, which in turn helps to enhance the work efficiency greatly. However, there exist some elements that could affect the performance of fiber optic. So, in order to achieve stable and excellent performance of the fiber, we should take these factors into consideration. Among which fiber optic loss is easy to be neglected sometimes, but it is of significant importance for engineers when selecting and dealing with fiber optics. This article aims to provide some useful information about fiber optic loss in detail.

It is universally known that fiber optic cable transmits data as pulses of light go through tiny tubes of glass. During the process the light travels through the core of fiber optic, and the strength of it surely becomes lower. Naturally, the signal strength becomes weaker. This loss of light power is generally called fiber optic loss or attenuation. While in power lever, this decrease is described in dB. Something happened during the transmission of data and caused fiber optic loss. Therefore, to transmit optical signals smoothly and safely, it is essential to decrease fiber optic loss. So, firstly we should try to figure out where the loss comes from. The fiber optic loss falls into two aspects: internal reasons and external causes, which are also known as intrinsic fiber core attenuation and extrinsic fiber attenuation.

Intrinsic Fiber Core Attenuation

Internal reasons of fiber optic loss are caused by the fiber optic itself, which is also known as intrinsic attenuation. Basically, there are two main causes of intrinsic attenuation: light absorption and scattering.

Light absorption is the major cause of fiber optic loss during optical transmission, which means the light is absorbed in the fiber by the materials of fiber optic. Thus light absorption is also known as material absorption. Actually the light power is absorbed and transferred into other forms of energy like heat because of molecular resonance and wavelength impurities. Besides, atomic structure in any pure material may absorb selective wavelengths of radiation. Since it is impossible to manufacture materials that are totally pure, fiber optic cable manufacturers choose to doping germanium and other materials with pure silica to optimize the fiber optic core performance.

Scattering is another main cause of fiber optic loss. It refers to the scattering of light caused by molecular level irregularities in the glass structure. When the scattering happens, the light energy is scattered in all directions. Some of them keep traveling in the forward direction, but the light that doesn’t scatter in the forward direction could be lost in the fiber optic link as shown in the following picture. Thus, to reduce fiber optic loss caused by scattering, the imperfections of the fiber optic core should be removed, and the fiber optic coating and extrusion should be carefully controlled.

scattering-in-fiber-optic

Extrinsic Fiber Attenuation

What we have mentioned above just serves as one aspect that causes fiber optic loss, the other one which is extrinsic fiber attenuation also plays an essential role in the loss of fiber optic. Extrinsic fiber attenuation is usually caused by improper handling of fiber optic. Thus, there are two main types of extrinsic fiber attenuation that may take place in fiber optic cable installation: bend loss and splicing loss.

Bend loss is a common problem generated by improper fiber optic handling that causes fiber optic loss. Literally, it is caused by fiber optic bend. There are two basic types of bend loss: one is micro bending, the other is macro bending (shown in the following picture). Macro bending refers to a large bend in the fiber (with more than 2mm radius). To reduce fiber optic loss, the following causes of bend loss should be noted:

  • Fiber core deviate from the axis;
  • Defects of manufacturing;
  • Mechanical constraints during the fiber laying process;
  • Environmental variations like the change of temperature, humidity or pressure.Bend loss in fiber optic

Fiber optic splicing can also result in extrinsic fiber attenuation. As it is inevitable to connect one fiber optic to another in a fiber optic network, the fiber optic loss caused by splicing cannot be avoided. However, it can be reduced to minimum with proper handling. Using fiber optic connectors of high quality and fusion splicing can help to reduce the fiber optic loss effectively.

fiber optic loss

Conclusion

The picture above shows the main causes of loss in fiber optic cable of different types. Since efficient transmission of light at the operational wavelengths is the primary function of fiber optics needed for a range of applications, the fiber optic loss and the potential for its minimization are of great importance in the efficient and economic use of fiber optics. For the purpose of reducing the intrinsic fiber core attenuation, it is necessary to select the proper fiber optic and suitable optical components for the applications, while for reduction of extrinsic fiber attenuation, it would be better to handle the fiber optic properly and splice it with cautious.