How to Optimize Your Network Performance with LC Assemblies?

High-density and compact data center cabling has become the consequent trend as the rapid development of fiber optic communication. Under this trend, LC assemblies, like the LC connector, LC adapter and LC attenuator, are more and more popular in the applications of cable television (CATV), fiber-to-the-home (FTTH) and dense wave division multiplexing (DWDM) Markets. Today this post intends to explore how to optimize network performance with LC assemblies.

LC Adapter for Easy Installation

It’s familiar to us that fiber optic adapters are used to connect fiber optic components with the same or different interfaces. Due to their ability to interconnect two connectors, they are widely applied in optical management systems. And nowadays there are various LC adapters available in the market for both single mode and multimode applications. Take the quad LC adapter for example, Quad LC adapters, designed for high-density applications, provide 4-position LC adapter solution in a traditional duplex SC footprint. The mating sleeve can connect four duplex or eight simplex LC fiber optic cables, saving more space and bring more flexibility.

Quad Plastic LC Fiber Optic Adapters

LC Attenuator for Better Transmission Quality

As we all know, signal strength needs to be reduced in some case. For instance, if a transmitter delivers too much light power, at the receiver end the power must be reduced by using fiber optic attenuator. Or it may degrade the bit error ratio (BER). LC attenuator is a type of widely applied fiber optic attenuator. It is designed to provide horizontal spectral attenuation over the full spectrum vary from 1260nm to 1620nm in single mode transmission. Therefore the LC attenuators can expand the capacity of optical networks by using the E-band (1400-nm window) for optical transmission.

LC fiber optic attenuator

LC HD Plus+ Fiber Cable for High Density Application

Designed with flexible “push-pull tab” uniboot connector, bend insensitive fiber and ultra-low insertion loss, LC HD plus+ fiber cables are the best choice for high-speed, high-bandwidth 1GbE and 10GbE networks in data centers. People with working experiences in data centers may know it’s not an easy task to add or remove one connector in numerous network cables. But with the push-pull tab uniboot connector, this problem can be solved perfectly. Firstly, the LC uniboot connector encloses two fibers firmly in a single cable, saving cable management space greatly. Secondly, the push-pull design enables connectors to be extracted or inserted into the port freely, which simplify the connectivity problems of limited access to the connector.

LC HD Plus+ Fiber Cable

LC Mux/Demux for More Flexibility in WDM Network

CWDM and DWDM Mux/Demux play an important role in combining data rate of different wavelengths over the same fiber cable to increase network capacity. No matter CWDM or DWDM Mux/Demux, there are several types of ports on them to ensure the normal function: channel port and line port. Of course, some Mux/Demux also have an expansion port and monitor port. A LC Mux/Demux means the LC Mux/Demux has LC connector for interfacing. It’s known to us that LC design is popular in fiber optic links. Mux/Demux with LC interface is easy to install and add WDM capacity to an existing network.

The following picture shows how to use two CWDM Mux/Demux at the same time to increase the wavelengths and expand the network capacity. The 8 CH and 4CH CWDM Mux/Demux are connected using the expansion port (LC interface).

stack-two-cwdm-mux

Summary

LC interface is the result of increased demands for smaller easier-to-use fiber connectivity. And a wide range of optical components with LC interface are widely used in optical networks. This article just introduces parts of them. Some other LC assembles such as optical transceivers, LC pigtails and LC adapter panels are available in Fiberstore. If you want to know more details, please visit FS.COM.

100G QSFP28 Transceiver Overview and How to Choose It

It’s no denying that today’s data centers are moving from 10G to 40G and 100G quickly. On this road, data explosion is getting faster, which result in great demand for cost-effective 100G optics. And the commonly used 100G transceivers are CFP, CFP2, CFP4 and QSFP28, especially the QSFP28. Today this article mainly introduces four types of 100G QSFP28 transceiver and the comparison between them to help you choose a suitable one.

Overview of 100G QSFP28 Transceiver
100G QSFP28 SR4 Transceiver

The 100G QSFP28 SR4 transceiver is a full-duplex optical module, offering four independent transmit and receive channels, each capable of 25Gb/s operation for an aggregate data rate of 100Gbps to 100 meters on OM4 multimode fiber (MMF). It’s fully compliant with QSFP28 Multi-Source Agreement (MSA) and can offer increased port density and total system cost savings for future data center and networking use. When connected to transmission links, an optical fiber ribbon cable is plugged into the QSFP28 modules receptacle via the MTP/MPO connector, and the guide pins inside the receptacle ensure the proper alignment. Besides, this QSFP28 transceiver offers high functionality and feature integration, accessible via a two-wire serial interface which is available for more complicated control signals and digital diagnostic information.

100G-QSFP28-SR4

100G QSFP28 LR4 Transceiver

The 100G QSFP28 LR4 transceiver is a fully integrated 4x25Gbit/s optical transceiver module, designed for use in data centers and high performance computing network links on up to 10km of single mode fiber (SMF). They are compliant with QSFP28 MSA, IEEE 802.3ba and IEEE 802.3bm CAUI-4. When connected to data transmission links, it converts four input channels of 25Gb/s electrical data to four channels of LAN WDM optical signals and then multiplexes them into a signal channel for 100Gb/s optical transmission. While on the receiver side, the module demultiplexes the 100G optical signals into four output channels and converts them into electrical data.

100G-QSFP28-LR4

100G QSFP28 PSM4 Transceiver

Defined by the 100G PSM4 MSA, PSM4 is a little different from QSFP28 SR4 transceiver. It uses four parallel lanes (four transmit and four receive) operating on each direction. Each lane carries 25G optical transmission. Therefore, eight single mode fibers are needed when PSM4 is deployed in transmission links. And the reach of PSM4 is up to 500m on single mode fiber, compensating for the transmission distance defect between QSFP28 SR4 and QSFP28 LR transceiver.

100G-QSFP28-PSM4

100G QSFP28 CWDM4 Transceiver

CWDM4 routes four 25G optical transmissions down a single fiber, which is like the PSM4. But it has longer reaches of up to 2km on SMF. And CWDM4 uses multiplexer and de-multiplexer to reduce the number of fibers to two rather than eight. When connected into transmission links, on the transmitting side, signals are multiplexed into one channel and transmitted through the SMF; then on the receiving side, the incoming signals are demultiplexed into four separated channels (shown as below).

100G-QSFP28-CWDM4

How to Choose?

With a number of 100G optical transceivers emerged, many factors should be taken into consideration when choose suitable transceivers. The key features of the 100G QSFP28 transceivers are listed below.

100g QSFP28 Transceivers

As shown in the table, cable type, interface type, fiber count and reach are needed to be considered when purchasing transceivers. For example, in the terms of reach, except the shortest (QSFP28 SR4) and the longest (QSFP28 LR4), PSM4 and CWDM4 are battling out in the 2km range. Here is a simple chart that may help to illustrate the difference between the two. As have mentioned above, PSM4 doesn’t use MUX/DEMUX, which determines its price is lower than CWDM4. However, as the transmission distance increases, the cost will grow quickly since it deploys eight-fiber transmission links.

PSM4 vs CWDM4

In summary, there are various types of 100G transceivers on the market. Different companies and operators have different requirements for their links and applications. So choosing a suitable 100G QSFP28 transceiver should be based on your practical situations. If you want to know more about 100G QSFP28 optical transceivers, welcome to visit FS.COM.