Single mode media converter VS multimode media converter


Optical media converter is a medium for transmitting short distance electrical signals and long distance optical signals. Because some short distance electrical signals can not be covered in some network environment, must use optical fiber to extend the transmission distance. The cost of upgrading copper wire to fiber is too high, so the application of media converter is more and more extensive.

Media converter is divided into single mode and multi-mode, the most fundamental difference is the transmission distance.

The operating mode of single mode media converter is single node and one port signal transmission, so the signal transmission distance is relatively long, which constitutes the construction of trans metropolitan area network;

Multimode media converter is just the opposite, its working mode is multi node, multi port signal transmission, so the signal transmission distance is relatively short, but the price is low, easy to use, mostly used for LAN internal construction.

Since media converters are similar in appearance, how can we distinguish single mode and multimode media converter? Let’s learn together!

1.See if there are S and M in the model. S for single mode, M for multimode.

2.From the transmission mode, the single mode media converter receives and transmits data on the same optical fiber patch cord , while the multimode media converter is on the two optical fibers.

3.Pull out dust cap to see inside interface color, generally the TX and RX interface inner side of single mode media converter are coated with white ceramics, the interface of the multimode is brown.

4.From the transmission distance, single mode media converter is from 20KM to 120KM, while multimode is 2KM to 5KM.

5.If the media converter is already used, can be distinguished by the color of patch cord. The yellow generally represents the single mode, and the orange represents the multimode.

Above are some methods to distinguish single mode and multi-mode media converters. In fact, there is no good or bad between the two, but the applicable network environment is not the same, how to choose should according to the use environment. It is important to note that single mode media converter can operate normally on single-mode and multimode optical fibers, but multimode media converter can not work on single-mode optical fiber. For more media converter knowledge, welcome to visit our

More Knowledge about Media Converter


Today we want to share some about the media converter with you after some customers asked about it.

Media converter is made up for the traditional Ethernet short transmission distance to realize long distance transmission of the signal.

Media converter is a transparent bidirectional converter to provide the data signal to Ethernet optical data signals. It can also break the limitation of 100m distance transmission for the Ethernet cable transmission.

Media converter are widely used in the higher data flow and higher performance Ethernet environment, such as Telecom, Broadcast and television, networks and so on.

Ethernet Media Converter have two types of the connector port: RJ54 optical port and optical port such as SC port,

RJ45 port is used for connecting the electric cable,

Optical port is used for connecting the optical port.

Media converter is usually used with the Optical fiber patch cords to extend the transmission distance, and also have a great function when connecting the metropolitan areas to a wider networks.

Media converter realized the kilometers to even hundred kilometers of long distance transmission when using the optical cable. support many types of the media convert for different rates and connecting port.

All the media converter will have the switch testing and aging testing before packaging to guarantee the quality.

Application of 25G SFP28 optical module in 5G fronthaul


In the 5G network architecture, the front-pass optical module is upgraded from 10G to 25G. This article will introduce the application of 25G SFP28 optical module in 5G fronthaul.

25G SFP28 dual fiber gray optical module

25G typical dual-fiber gray optical module supports transmission distances of 300 meters and 10 kilometers, 25G SFP28 300meters multimode optical module is mainly used for interconnection under the base station tower, and 25G SFP28 10 km single-mode optical module is mainly used for long distances of stations or links with larger link losses between AUU and access to the machine room (site) between the fiber direct connection scenario. 25G multimode optical module center wavelength of 850nm, duplex LC interface, multimode, operating temperature of 0 °C ~ 70 °C, transmitted optical power of -8.4 to +2.4dBm, the use of OM4 multimode fiber can be transmitted to 100 meters.

25G SFP28 10km single-mode optical module center wavelength of 1310nm, duplex LC interface, single-mode, support commercial (0 °C ~ 70 °C) and industrial grade (-45 °C ~ 85 °C) operating temperature range, transmit optical power of -7 ~ +3dBm, with single-mode OS2 optical fiber transmission distance of up to 10 km.

25G SFP28 BIDI single fiber gray optical module

BIDI optical transceiver has the advantages of saving optical fiber resources and high-precision time synchronization, and can support transmission distances of 10 kilometers, 15 kilometers and 20 kilometers. The transmitter of the 25G BIDI optical transceiver product adopts the uncooled DFB TO form, the center wavelength is 1270nm/1330nm, and the receiving end adopts the high-sensitivity 25G PIN TO form, and the receiving wavelength is 1330nm/1270nm, respectively. The product follows the mature optical device coaxial packaging process platform to achieve single fiber bidirectional and optical interface rate of 25.78Gbps.

25G SFP28 CWDM module

In the early stage of 5G network construction, the fronthaul is mainly based on optical fiber direct drive, accompanied by high-frequency networking and deep coverage of low-frequency add-points, in order to make full use of existing optical fiber resources, the use of CWDM optical modules will become a useful supplement. The 25G SFP28 CWDM uses a 1270nm-1370nm (20nm interval) CWDM DML laser and PIN receiver, or a 1470nm-1570nm (20nm interval) CWDM EML laser and APD receiver, which has a built-in CDR circuit in the receive and transmit channels, with a maximum speed of up to 25.78Gbps.

The number of optical transceivers used in 5G fronthaul on base stations has increased from 6 to 12 in the original 4G, and it is estimated that the construction volume of 5G base stations will reach 600,000-800,000 stations, so the demand for 25G fronthaul optical modules will reach 7.2 million to 9.6 million. In addition, with the improvement of operators’ CRAN deployment requirements, it will bring about the growth of demand for wavelength division multiplexing IPL Modules, and 25G CWDM Modules may become mainstream.

how optical modules are used in base stations?


The communication triangular tower is composed of antenna, computer room, base station, feeder, and supporting equipment. The antenna is at the top of the triangular tower, and there is a computer room under the tower. The computer room is mainly for the base station, and the base station is the equipment that transmits wireless signals. The base station is logically divided into two parts: BBU and RRU. RRU is responsible for signal transmission and reception, and BBU is responsible for signal processing. The feeder is used to connect the antenna and the base station, and the supporting equipment is mainly the power supply and air conditioner.

The distributed site separates the BBU and RRU of the base station. The RRU is hung on the tower, and the BBU is placed in the equipment room under the tower. The CPRI protocol transmits physical layer data between the BBU and the RRU, which not only includes the bearer data, but also contains a large amount of physical data. layer information.

 The transmission carriers connecting BBU and RRU devices are optical modules and optical fibers. In 2/3/4G networks, 10Gbps optical modules are generally enough for CPRI interfaces. In 5G networks, CPRI is also upgraded to eCPRI. Currently, 5G of the bearer network mainly uses 25Gbps optical modules.

Next, will introduce the types of optical modules used by 10G SFP+ and 25G SFP28 optical modules to connect BBU and RRU devices.

10G SFP+ CPRI SR 300M(Industrial)

The product model of is ES85X-3LID03, which adopts 850nm VCSEL laser and PIN photodetector, and the operating temperature range is -40℃-85℃. It conforms to SFP28 MSA, IEEE 802.3 25GBASE-SR Ethernet and CPRI standards. Optical fiber transmission distance up to 300m (OM3).

 25G SFP28 CPRI/eCPRI SR 100M(Industrial)

The product model of is ES2852X-3LID01. It adopts 850nm VCSEL laser and PIN photodetector, and the operating temperature range is -40℃-85℃. It conforms to SFP28 MSA, IEEE 802.3 25GBASE-SR Ethernet and CPRI/eCPRI standards. Multimode fiber transmission distance up to 70m (OM3) or 100m (OM4).

The arrival of 5G has brought huge changes to our lives. The most obvious thing is that the network speed has become faster, and the mobile phone has changed from 4G to 5G mobile phone. The development of technology and VR.

How to choose DAC high-speed cable?


DAC high-speed cable is a low-cost and short-distance connection solution for data center equipment. It consists of a cable and optical fiber transceiver devices at both ends of the cable. Because of the high cost performance, the interconnection application between short-distance network equipment is widely welcomed. At present, there are many specifications of DAC high-speed cables on the market. If you want to buy a cost-effective high-speed cable product, summarizes the following considerations for everyone here.

1. There are two types of high-speed cables, active and passive. The difference between the two is that the active DAC high-speed cable has an additional driver chip. At the same time, active optical cables do not need power supply skills to display their characteristics, while active optical cables require external power to display their characteristics. Under normal circumstances, when the transmission distance exceeds 5 meters, in order to reduce the signal interference problem, it is most appropriate to choose an active DAC high-speed cable. Passive high-speed cables do not amplify or equalize optical signals during transmission. The active high-speed cable will also amplify the optical signal while transmitting it, thereby increasing the transmission distance. Therefore, the transmission distance of an active high-speed cable is longer than that of a passive high-speed cable, but its price is also more expensive.

2、When purchasing, we need to determine the cable length and AWG value. The common AWG values for high-speed cables are 24AWG, 28AWG and 30AWG. As AWG24 is thicker and heavier than AWG30, the longer the length of AWG24, the less convenient it is to use than AWG30, and the bending sensitivity is also limited. Therefore, in long-distance transmission, it is appropriate to choose a larger AWG.

3. Determine the transmission rate and connector type. DAC high-speed cables can be divided into 10G SFP+ DAC high-speed cables, 25G SFP28 DAC high-speed cables, 40G QSFP+ DAC high-speed cables, and 100G QSFP28 DAC high-speed cables according to different transmission rates. It is used for direct connection of short-distance equipment in the data center. In addition, in order to meet the needs of user network upgrades, DAC high-speed cables, 40G QSFP+ DAC high-speed cables and 100G QSFP28 DAC high-speed cables are equipped with branch cable packaging, which can be used for 40G to 4*10G, 100G to 4* In the 25G network upgrade application scenario.

introduction of 10G SFP + DAC cable


10G SFP+ direct attach cable is a common cable for data center overhead cabling, which is used to connect small access switches and servers. 10G SFP+ direct attach cable is a low cost solution instead of optical module and AOC active optical cable. It has the advantages of low power consumption and low cost. It is an ideal choice for the connection between server and switch to realize short distance direct attach interconnection.

10G SFP+ DAC is a copper cable with two ends of SFP+ connectors, which supports up to 10 Gb/s rate and can be backward compatible with 1 Gb/s. Different from optical module and AOC active optical cable, DAC transmits electrical signal directly through copper wire, while optical module and AOC active optical cable convert electrical signal into optical signal for transmission.

There are no lasers, detectors, amplifiers and other optical devices and MCU control chips in the two ends of the DAC, and the price of copper cable is cheaper than that of optical cable. Therefore, the overall price of DAC direct attach cable is much cheaper than that of optical module and AOC active cable, which can greatly reduce the interconnection cost between devices.

10G SFP+ DAC supports a passive copper cable length of 7m. Since the DAC is purely electrically driven, the transmission distance is generally not far. Unless it is an active cable, the transmission distance will be increased after adding an amplifier.

10G DAC cabling can save connection equipment, do not need to use patch panels, and the power consumption is less than 0.2W. Servers and network equipment can be directly connected to TOR switches, which can indirectly save investment costs. direct attach cable assemblies can meet and exceed the performance and reliability requirements of Gigabit Ethernet and Fibre Channel industry standards. It is a high-performance, cost-effective I/O solution for 10Gb Ethernet and 10G Fibre Channel applications.

The 10G SFP+ direct attach cable provided by has enhanced EMC / EMI performance and can resist electromagnetic interference. Moreover, the electromagnetic energy generated by the cable does not interfere with other equipment, nor is it interfered by the electromagnetic energy of other equipment. In order to prevent compatibility problems, we need to indicate the compatible equipment when we purchase DAC, so as to avoid that the DAC cable can not be used normally due to compatibility problems.

10G SFP+ DAC can be used in storage area network, network attached storage and switch fabric I / O in storage server, such as ultra-high bandwidth switch and router, data center wiring, high-density connection between infrastructure network equipment, etc. Finally, in the short distance interconnection scenario, based on low cost, low power consumption and other factors, recommends that you choose 10G DAC direct attach cable.

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