Most Popular Articles

• Huawei Completes 5G Key Technology Tests in the Field Trial Sponsored by IMT-2020 5G Promotion Group

  May 30, 2016 by Telecom News / 486 Views

  [Shenzhen, China, May 27, 2016] Huawei completed the first phase of key 5G technology tests as a part of a series field trials defined by the IMT-2020 5G Promotion Group. In April 2016, the outdoor macro-cell tests, conducted in Chendu, China, consist of a number of the foundational key enabling technologies and an integrated 5G air-interface. The test results successfully demonstrated that the new 5G air interface technology can effectively improve spectrum efficiency and to meet diverse service requirements for 5G defined by ITU-R.

  
  Huawei completes 5G key technology tests in 5G field trial

  Strong Promotion for Global Partnership on 5G Technology Innovation and a Global 5G Standard

  Launched by China Academy of Information and Communication Technology (CAICT), the IMT-2020 5G Promotion Group aims to foster a joint effort to promote 5G technology evaluation and field test among the global mobile industry and ecosystem to ensure the successful commercial deployment by 2020. One of the key objectives for IMT-2020 5G Promotion Group is to realize the 5G vision for the enhanced mobile broadband service as well as to create the new capabilities for 5G to enable the IoT and vertical services, this represents the unprecedented technical challenges such as to realize 10Gbps or peak rate 20Gbps user data rate, 100 billion connections, and 1 ms of end-to-end network latency for the 5G air interface.

  Early this year, IMT-2020 5G Promotion Group announced a three phase 5G networks trial plan, spanning from 2016 to 2018, with a first phase test from September 2015 to September 2016. The first phase test is focused on key radio technologies and performance test.

  As one of the core members in the IMT-2020 5G Promotion Group, Huawei actively contributed IMT-2020 5G Promotion Group and 5G technology test. In addition, Huawei established an extensive collaboration with CAICT, China Mobile, China Unicom, and China Telecom in the Chinese operator community to explore the innovative air-interface technologies to achieve best spectral efficiency and massive links capabilities. Huawei’s effort is focused on New Radio (NR) technology, which includes the optimized new air-interface, full-duplex and massive MIMO technologies, these are the enabling technologies to achieve the superior end-user experience for the emerging mobile broadband service such as 4K, 8K and virtual reality and augmented reality.

  Best-in-Class Test Results Using 5G New Air Interface

  The 5G air interface technology has been implemented through three novel foundational technologies, i.e., filtered Orthogonal Frequency Division Multiplexing (F-OFDM), Sparse Code Multiple Access (SCMA) and Polar code to meet 5G requirements and performance targets.

  F-OFDM technology is the basis for creating ultra-flexible air-interface to adaptively fit all the 5G use-case scenarios defined by ITU-R with a single radio technology platform. It allows multiple concurrent radio numerologies and frame structure to deliver very diverse services; F-OFDM can ensure the future-proof for the 5G system to meet emerging innovative services requirements. The test results showed that F-OFDM can increase system throughput by 10% using those free guard bands in LTE system. In addition, F-OFDM supports asynchronous transmission from different users. Test results showed that it will provide 100% higher system throughput compared with that in LTE system in the presence of mixed service on the same carrier frequency with mixed radio numerologies. .

  SCMA is to support massive connections and obtain higher system throughput simultaneously via the joint optimization on sparse SCMA codebook design and multi-dimensional modulation. It can further consider optimization on power allocation among different SCMA layers especially in downlink to improve total system throughput. The test results showed that SCMA is to increase the uplink connection number by 300% and at the same time increased the downlink system throughput up to 80%.

  For Polar code, it allocates information to the highly reliable data locations in the code structure to transmit useful information of user and at the same time it supports channel coding of any code rate with an appropriate code construction to fit any future service requirements. The test results showed that Polar code provided coding gain from 0.5dB to 2.0dB compared with Turbo code used in LTE system.

  System Integration of Innovative 5G Air Interface Technologies

  The flexible system integration of several innovative 5G air-interface technologies, namely, F-OFDM, SCMA and massive MIMO has been verified in the first phase of key 5G technology tests. In the test, multi-user MIMO (MU-MIMO) supported up to 24 users and up to 24 parallel layers transmission on the same time-frequency resources. The test results showed that MU-MIMO can achieve 3.6Gbps cell average throughput using 100MHz system bandwidth, it is almost 10 times of that in LTE baseline system.

  The trial has validated the optimal integration of the above new radio technologies and the capability of flexible 5G air-interface technologies, the trial is also served as a technical re-risk to support the on-going 3GPP standardization work.

  Full Duplex Implemented in the First Phase of 5G Test

  Full Duplex mode has also been tested in the first phase of 5G test. In the initial test stage on Full Duplex, it allows simultaneous transmitting and receiving of data at the base station with three level cascaded technologies, namely, passive analog cancellation, active analog cancellation, and digital cancellation. The test results showed that the Full Duplex can provide self-interference cancellation capability more than 113dB in real world environment and result in a total 90% system throughput gain over the conventional half duplex mode used today.

  Huawei has successfully completed the first phase test of 5G technologies in China. "The trial of 5G technologies in China will be a great contribution to 5G applications in the future.” Dr. Wen Tong, Huawei 5G Chief Scientist emphasized that, "As a member of the IMT-2020 5G Promotion Group, Huawei is pleased to work with CAICT, China Mobile, China Unicom, and China Telecom, and took the initiative to be the first to complete 5G key technologies tests and corresponding system integration test based on our proposed 5G new air interface."

  He also announced the plan of the second phase of 5G test which will focus mainly on the wide coverage, high hotspot capacity, and massive connections with high reliability, low latency with reduced power consumption.

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• The Composition and Classification of Fiber Optic Cables

  Feb 6, 2016 by Articles / 485 Views

  To satisfy optical, mechanical and environmental performances and specifications, fiber optic cable was born. The fiber optic cable uses one or more fibers that placed in the sheath as the transmission medium. Accompanied by the continuous advancement of network technology, fiber optic cable constantly participates in the construction of telecommunications networks, the construction of the national information highway, Fiber To The Home (FTTH) and other occasions for large-scale use. Although fiber optic cable is still more expensive than other types of cable, it's favored for today's high-speed data communications because it eliminates the problems of twisted-pair cable and so fiber optic cable is still a good choice for people. But how to really get a good performance, state-of-the-art products, we need to understand some basics to identify the types of fiber optic cables.

  Composition

  Fiber optic cable consists of the core, the cladding and the coating. The core is a cylindrical rod of dielectric material. Dielectric material conducts no electricity. Light propagates mainly along the core of the fiber. The core is generally made of glass. The core is described as having a radius of (a) and an index of refraction n1. The core is surrounded by a layer of material called the cladding. Even though light will propagate along the fiber core without the layer of cladding material, the cladding does perform some necessary functions. (The basic structure of an optical fiber is shown in the following figure.)

   

  Structure: Core: This central section, made of silica, is the light transmitting region of the fiber.Cladding: It is the first layer around the core. It is also made of silica, but not with the same composition as the core. This creates an optical wave guide which confines the light in the core by total reflection at the core-cladding interface.Coating: It is the first non-optical layer around the cladding. The coating typically consists of one or more layers of a polymer that protect the silica structure against physical or environmental damage.Strengthening Fibers: These components help protect the core against crushing forces and excessive tension during installation. The materials can range from Kevlar to wire strands to gel-filled sleeves.Cable Jacket: This is the outer layer of any cable. Most fiber optic cables have an orange jacket, although some may be black or yellow. The jacket material is application specific. The cable jacket material determines the mechanical robustness, aging due to UV radiation, oil resistance, etc.

   

  Jacket Material: PolyEthylene (PE): PE (black color) is the standard jacket material for outdoor fiber optic cables. PE has excellent moisture- and weather-resistance properties. It has very stable dielectric properties over a wide temperature range. It is also abrasion-resistant.PolyVinyl Chloride (PVC): PVC is the most common material for indoor cables, however it can also be used for outdoor cables. It is flexible and fire-retardant. PVC is more expensive than PE.PolyVinyl DiFluoride (PVDF): PVDF is used for plenum cables because it has better fire-retardant properties than PE and produces little smoke.Low Smoke Zero Halogen (LSZH) Plastics: LSZH plastics are used for a special kind of cable called LSZH cables. They produce little smoke and no toxic halogen compounds. But they are the most expensive jacket material. 

   

  Fiber Size

  The size of the optical fiber is commonly referred to by the outer diameter of its core, cladding and coating. Example: 50/125/250 indicates a fiber with a core of 50 microns, cladding of 125 microns, and a coating of 250 microns. The coating is always removed when joining or connecting fibers. A micron (µm) is equal to one-millionth of a meter. 25 microns are equal to 0.0025 cm. (A sheet of paper is approximately 25 microns thick).

   

  Classification

  Besides the basics, Fiber optic cables can be classified by other ways.

  Transmission Mode:

  • Multi-Mode Fiber (MMF) Cable: Center glass core is coarse (50 or 62.5 µm). It can transmit a variety of patterns of light. However, because its dispersion is large, which limits the frequency of the transmitted digital signal, and with increasing distance, the situation will be more serious. For example, 600Mb/km of 2km fibers provide the bandwidth of only 300 Mbps. Therefore, MMF cable's transmission distance is relatively short, generally only a few kilometers. General MMF patch cables are in orange, also some are gray, joints and protection are beige or black. 
  • Single-Mode Fiber SMF Cable: Center glass core is relatively fine (core diameter is generally 9 or 10 µm), only one mode of light transmission. Therefore, the dispersion is very small, suitable for remote communication, but it plays a major role in the chromatic dispersion, so that SMF cable has a higher stability requirement to the spectral width of the light source, just as narrower spectrum width, better stability. General SMF patch cables are in yellow, with joints and cases in blue.

   

  Transmission Way:

  • Simplex Cable: Single strand of fiber surrounded by a 900µm buffer then a layer of Kevlar and finally the outer jacket. Available in 2 mm or 3 mm and plenum or riser jacket. Plenum is stronger and made to share in fire versus riser is made to melt in fire. Riser cable is more flexible.
  • Duplex Cable: Two single strands of fiber optic cable attached at the center. Surrounded by a 900µm buffer then a layer of Kevlar and finally the outer jacket. In data communications, the simultaneous operation of a circuit in both directions is known as full duplex; if only one transmitter can send at a time, the system is called half duplex.

   

  Cable Core Structure:

  • Central Tube Cable: Fiber, optical fiber bundles or fiber optic cable with no stranding directly into the center position.
  • Stranded Tube Cable: A few dozens or more root fiber or fiber tape unit helically stranded around the central strength member (S twist or SZ twisted) into one or more layers of fiber optic cable.
  • Skeleton After Tube Cable: Fiber or fiber after spiral twisted placed into the plastic skeleton cable slot.

   

  Fiber Road Laying:

  • Aerial Cable: Aerial cables are for outside installation on poles. They can be lashed to a messenger or another cable (common in CATV) or have metal or aramid strength members to make them self supporting. The cable shown has a steel messenger for support. It must be grounded properly. A widely used aerial cable is optical power ground wire which is a high voltage distribution cable with fiber in the center. The fiber is not affected by the electrical fields and the utility installing it gets fibers for grid management and communications. This cable is usually installed on the top of high voltage towers but brought to ground level for splicing or termination. 
  • Direct-Buried Cables:
    • Armored Cable: Armored cable is used in direct-buried outside plant applications where a rugged cable is needed and/or rodent resistance. Armored cable withstands crush loads well, needed for direct burial applications. Cable installed by direct burial in areas where rodents are a problem usually have metal armoring between two jackets to prevent rodent penetration. Another application for armored cable is in data centers, where cables are installed underfloor and one worries about the fiber cable being crushed. Armored cable is conductive, so it must be grounded properly. 
    • Breakout Cable: Breakout cable is a favorite where rugged cables are desirable or direct termination without junction boxes, patch panels or other hardware is needed. It is made of several simplex cables bundled together inside a common jacket. It has a strong, rugged design, but is larger and more expensive than the distribution cables. It is suitable for conduit runs, riser and plenum applications. It's perfect for industrial applications where ruggedness is needed. Because each fiber is individually reinforced, this design allows for quick termination to connectors and does not require patch panels or boxes. Breakout cable can be more economic where fiber count is not too large and distances are not too long, because it requires so much less labor to terminate.
  • Submarine Cable: Submarine cable is the cable wrapped with insulating materials, laying at the bottom of the sea, to set up a telecom transmission between countries.

   

  Cable State. Based on 900µm tight buffered fiber and 250µm coated fiber there are two basic types of fiber optic cable constructions:

  • Tight Buffered Cable: Multiple color coded 900µm tight buffered fibers can be packed tightly together in a compact cable structure, an approach widely used indoors, these cables are called tight buffered cables. Tight buffered cables are used to connect outside plant cables to terminal equipment, and also for linking various devices in a premises network. Multi-fiber tight buffered cables often are used for intra-building, risers, general building and plenum applications. Tight buffered cables are mostly built for indoor applications, although some tight buffered cables have been built for outdoor applications too.
  • Loose Tube Cable: On the other hand multiple (up to 12) 250µm coated fibers (bare fibers) can be put inside a color coded, flexible plastic tube, which usually is filled with a gel compound that prevents moisture from seeping through the hollow tube. Buffer tubes are stranded around a dielectric or steel central member. Aramid yarn are used as primary strength member. Then an outer polyethylene jacket is extruded over the core. These cables are called loose tube cables. Loose tube structure isolates the fibers from the cable structure. This is a big advantage in handling thermal and other stresses encountered outdoors, which is why most loose tube fiber optic cables are built for outdoor applications. Loose-tube cables typically are used for outside-plant installation in aerial, duct and direct-buried applications. 

   

  Environment & Situation:

  • Indoor Cable: Such as distribution cables. Distribution cable is the most popular indoor cable, as it is small in size and light in weight. They contain several tight-buffered fibers bundled under the same jacket with Kevlar strength members and sometimes fiberglass rod reinforcement to stiffen the cable and prevent kinking. These cables are small in size, and used for short, dry conduit runs, riser and plenum applications. The fibers are double buffered and can be directly terminated, but because their fibers are not individually reinforced, these cables need to be broken out with a "breakout box" or terminated inside a patch panel or junction box to protect individual fibers.
  • Outdoor Cable: Outdoor fiber cable delivers outstanding audio, video, telephony and data signal performance for educational, corporate and government campus applications. With a low bending radius and lightweight feature, this cable is suitable for both indoor and outdoor installations. These are available in a variety of configurations and jacket types to cover riser and plenum requirements for indoor cables and the ability to be run in duct, direct buried, or aerial/lashed in the outside plant.

  To purchase your fiber cables, please click link below:

  Fiber Patch Cables

   

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• 40G QSFP+ Transceiver Modules and DAC/AOC Cables Installation Guide

  Feb 7, 2016 by Articles / 480 Views

  To install and remove the transceiver optics in a right way is very necessary to ensure the network to work stably and efficiently. Today, we are going to introduce an installation guide of QSFP transceivers and DAC/AOC cables in 40G network.

  40GbE QSFP+ Transceivers Overview

  40 Gigabit Ethernet (40GbE) aggregation switches are becoming more common in today's data centers. At the heart of the 40GbE network layer is a pair of transceivers connected by a cable. The transceivers are plugged into either network servers or a variety of components including interface cards and switches and connected via the cables such as OM3 and OM4 for multimode application. Additionally DAC (Direct Attach Copper) cables or AOCs (Active Optical Cables) are used for short interconnection as a more cost-effective alternative solution. QSFP+ (Quad Small Form-factor Pluggable Plus) is the most common 40GbE interface type, and also as a high-density 10GbE interface via QSFP+ breakout cables. QSFP+ interfaces a network device (switch, router, media converter or similar device) to a fiber optic or copper cable, supporting data rates from 4x10 Gbps and supports Ethernet, Fibre Channel, InfiniBand and SONET/SDH standards with different data rate options. Compared to CFP (C form-factor pluggable) transceiver modules, QSFP transceiver modules are more compact and more suitable for port-density application. The two basic interface specifications of QSFP+ modules respectively for multimode and single-mode applications are 40GBASE-SR4 and 40GBASE-LR4.

  40GBASE-SR4 QSFP+ Module

  The 40GBASE-SR4 QSFP+ module, conforming to the 802.3ba D3.2 (40GBASE-SR4) standard, provides a 40Gbps optical connection using MPO/MTP® optical connectors. This optical module integrates four data lanes in each direction with 40Gbps aggregate bandwidth and each lane can operate at 10.3125 Gbps. It is used in data centers to interconnect two Ethernet switches with 8 fiber parallel multimode fiber OM3/OM4 cables (transmission distance can be up to 100 meters using OM3 fiber or up to 150 meters using OM4 fiber).

   

  40GBASE-LR4 QSFP+ Module

  The 40GBBASE-LR4 QSFP+ module, conforming to the 802.3ba (40GBASE-LR4) standard, provides a 40Gbps optical connection using LC optical connectors. This optical module integrates four data lanes in each direction with 40Gbps aggregate bandwidth and each lane can operate at 10.3125 Gbps. It is most commonly deployed between data center or IXP sites with single-mode fiber up to 10 km.

   In addition, to satisfy a number of different objectives including support for MMF and SMF compatibility, there are other types of QSFP+ modules offered by different vendors.

  How to Install/Remove QSFP+ Transceivers and DAC/AOC Cables

   

  Preparations

  To protect a QSFP+ module or cable from ESD (electro-static discharge) damage, before installing or removing a QSFP+ module or cable, be remembered that always wear an ESD wrist strap and make sure that it makes good skin contact and is securely grounded (If you are using ESD gloves, wear the wrist strap outside the ESD glove).

  To Install or Remove a QSFP+ Transceiver Module

  There are two types of clasp designed for a QSFP+ transceiver module—plastic clasp or a metallic clasp. Here uses the metallic clasp type as an example.

  To Install a QSFP+ Transceiver Module

  Step 1. Remove the QSFP+ module from its antistatic container and remove the dust covers from the module optical connector.
  Step 2. Remove any rubber dust covers from the port where you are installing the QSFP+ module.
  Step 3. Pivot the clasp of the module up. (Skip this step if the clasp is plastic.)
  Step 4. Align the module with the port in the chassis, as shown in Figure 1.

  
  Figure 1. Aligning the module with the port

  Step 5. Holding the module, gently push in the module until it is firmly seated in the port.(see Figure 2.)

  
  Figure 2. Install the QSFP+ module to port

  Step 6. Immediately attach the patch cord with MPO connector or duplex LC connector to the QSFP+ transceiver module.(see Figure 3.)

  
  Figure 3. Install the patch cord to the module

  Note: Install the dust plug for the transceiver module if you are not to install an optical fiber into it.

  To Remove a QSFP+ Transceiver Module

  Step 1. Remove the optical fiber if any.
  Step 2. Pivot the clasp of the module down to the horizontal position. (Skip this step if the clasp is plastic.)
  Step 3. Holding the module, gently pull the module out of the port. (Figure 4)
  Step 4. Place the QSFP+ transceiver into an antistatic bag.

  
  Figure 4. Remove the QSFP+ module

  To Install or Remove a 40G QSFP+ Cable

  The installation and removal procedures are the same for QSFP+ DAC cables and QSFP+ AOC cables. Here uses a QSFP+ DAC cable as an example:

  To Install a QSFP+ DAC Cable

  Step 1. Align the QSFP+ transceiver module (with the clasp on top) at one end of the cable with the port in the chassis, as shown in Figure 5.
  Step 2. Horizontally and gently push in the module to fully seat it in the port.

  
  Figure 5. Installing a QSFP+ DAC cable

  To remove a QSFP+ DAC Cable

  Step 1. Gently press and release the QSFP+ transceiver module.(see Figure 6.)
  Step 2. Holding the cable, gently pull the clasp on the cable to pull out the transceiver module.

  
  Figure 6. Removing a QSFP+ DAC cable

  To Install or Remove a 40G QSFP+ to 4x10G SFP+ Cable

  40G QSFP+ to 4x10G SFP+ cable combines one 40G QSFP+ module on one end and four 10G SFP+ module on the other end. The installation and removal procedures of 40G QSFP+ connector are introdueced above. Here only introduced the installation and removal of 10G SFP+ module:

  To Install an SFP+ Transceiver Module

  Step 1. Align the module with the SFP+ port, with the golden plating facing the spring tab (see Figure 7.) in the SFP+ port. If the chassis has two rows of ports, the spring tab in a port is on the bottom in the upper row and on the top in the lower row.
  Step 2. Slightly press the module against the spring tab so you can push the module straight into the port.

  
  Figure 7. Installing an SFP+ transceiver module

  To Remove an SFP+ Transceiver Module

  Step 1. Press the module with your thumb, as shown by callout 1 in Figure 8.
  Step 2. Gently pull the clasp on the cable to pull out the transceiver module, as shown by callout 2 in Figure 8.

  
  Figure 8. Removing an SFP+ transceiver module

  Verifying the installation

  Execute the display transceiver interface command on the device to verify that the transceiver module or DAC/AOC cable is installed correctly. If the transceiver module and DAC/AOC cable information is displayed correctly, the installation is correct. If an error message is displayed, the installation is incorrect or the transceiver optics is not compatible.

  

  Conclusion

  As 40 GbE are widely deployed, 40G transceiver optics are ubiquitous. A good practice and correct installation are very important for 40G network system, not only to protect the 40G transceiver optics and device from damage, but also to ensure a stable performance for system. In addition, by executing the display transceiver interface command, we can verify whether the installation is correct. Of course, the premise is that the transceiver optics you use is fully compatible with your device. COMPUFOX offers a comprehensive line of high-compatible 40G transceiver optics, such as 40GBASE-SR4 QSFP+, 40GBASE-LR4 QSFP+ and 40G DACs and AOCs with competitive prices. See Links below:

  • QSFP+
    
  • QSFP+ Cables
  • QSFP+ to 4 SFP+ Cables
  • QSFP+ to 4 XFP Cables
  • QSFP+ to 4 LC Cables
  • QSFP+ to CX4 Cables

   

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• Optics and Cables Selection for Storage Area Network (SAN)

  Feb 7, 2016 by Articles / 476 Views

  Optics and cables are the most important infrastructures of network connectivity. In a storage area network (SAN), switches are used between servers and storage devices. This means that you should make connection with optics and cables between the server and switch, storage and switch as well as the switch and switch. Of course, according to different application environments, you should choose different optics and cables in order to get the best performance. Furthermore, you may need to consider the future expansion of your network. Thus, an economical and effective solution of optics and cables are very necessary.

  Key Factors Influencing Your Decision

  Firstly, there are some key factors which will influence your decision. Thus, you must make sure that what your network really requires. As we mentioned above, an SAN has server, storage device and switches. So, what should we consider in every section of the network?

  1. Server
  Bandwidth: Depending on the application load requirements, customers typically decide whether they want 1GbE, 10GbE, or 40GbE. In some cases, the decision may also be dictated by the type of traffic, e.g. DCB (Data center bridging) requires 10GbE or higher.Cost: Servers claim the highest share of devices deployed in any data center. Choosing a lower cost connectivity option results in a much lower initial deployment cost.Power: In any high density server deployment, a connectivity option which consumes lower power results in much lower OpEx.Distance: Servers are typically connected to a switch over a very short distance, i.e. typically within the same rack or, in some cases, within the same row.Cabling Flexibility: Some customer prefer to make their own copper cables due to variable distance requirement. This requirement limits the choice of connectivity to copper cables only.

   

  2. Storage
  Reliability: Typical storage traffic is very sensitive to loss. Even a minor loss of traffic may result in major impact on application performance.Qualification: Storage vendor qualification or recommendation plays an important role in this decision due to reasons such as customer support, peace of mind, etc.Latency: Any time spent in transition is time taken away from data processing. Reducing transition time results in much faster application performance. The result may have a direct impact on customers' bottom line, e.g. faster processing of online orders.

   

  3. Switch
  Bandwidth: On server facing ports, servers typically dictate the per port bandwidth requirement. However, per port bandwidth requirement for the network facing (switch-to-switch) ports denpends on multiple factors including amount of traffic generated by the servers, oversubscription ratios, fiber limitations, ect.Distance: An inter-switch or switch to router connection could range from a few inches to tens of kilometers. Generally, the price of optics increases as the distance increases.Latency: The network topology and application traffic profile (East-west, HPC (High Performance Computing), computer cluster, etc.) and influence the minimun latency that can be tolerated in the network.

   

  • Server to Switch Connectivity Solution

  

  • Storage to Switch Connectivity Solution

   

   

  • Switch to Switch Connectivity Solution

   

  

   COMPUFOX Solutions

  COMPUFOX  offers a comprehensive solution of optics and cables which supports your network from 1GbE to 100GbE. We have a great selection of 1000BASE-T/SX/LX SFP, BiDi SFP, 10GBASE-SR/LR SFP+, DWDM SFP+, whole series 40G QSFP+ optics and cables, as well as the 100G CFP2 and CFP4, etc. which help you solve the cost issue in fiber project. Especially the 40G QSFP+ optics, with the passive optic design, they can be compatible with all the equipment of all major brands. In addition, most of them are ready stock. See Links below:

  • CFP
  • CWDM
  • DWDM
  • GBIC
  • QSFP+
  • SFP+
  • SFP
  • X2
  • XENPAK
  • XFP
  • QSFP+ Cables
  • QSFP+ to 4 SFP+ Cables
  • QSFP+ to 4 XFP Cables
  • QSFP+ to 4 LC Cables
  • QSFP+ to CX4 Cables
  • SFP Cables
  • SFP+ Cables
  • SFP+ to XFP Cables

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• Introduction to Bi-Directional Transceiver Modules

  Feb 7, 2016 by Articles / 459 Views

  Almost all modern optical transceivers utilize two fibers to transmit data between switches, firewalls, servers, routers, etc. The first fiber is dedicated to receiving data from networking equipment, and the second fiber is dedicating to transmitting data to the networking equipment. But there is a type of fiber optic transceiver module called BiDi (Bi-Directional) transceiver to break this rule. What's BiDi transceiver? How does it work? And why people believe it will have broad market prospect? This tutorial will give you the answer.

  What's BiDi Transceiver?

  BiDi transceiver is a type of fiber optic transceivers which is used WDM (Wavelength Division Multiplexing) Bi-directional transmission technology so that it can achieve the transmission of optical channels on a fiber propagating simultaneously in both directions. BiDi transceiver is only with one port which uses an integral bidirectional coupler to transmit and receive signals over a single fiber optical cable. Thus, it must be used in pairs.

  How Does BiDi Transceiver Work

  The primary difference between BiDi transceivers and traditional two-fiber fiber optic transceivers is that BiDi transceivers are fitted with Wavelength Division Multiplexing (WDM) couplers, also known as diplexers, which combine and separate data transmitted over a single fiber based on the wavelengths of the light. For this reason, BiDi transceivers are also referred to as WDM transceivers.

  To work effectively, BiDi transceivers must be deployed in matched pairs, with their diplexers tuned to match the expected wavelength of the transmitter and receiver that they will be transmitting data from or to.

  For example, if paired BiDi transceivers are being used to connect Device A (Upstream) and Device B (Downstream), as shown in the figure below, then:

  Transceiver A's diplexer must have a receiving wavelength of 1550nm and a transmit wavelength of 1310nmTransceiver B's diplexer must have a receiving wavelength of 1310nm and a transmit wavelength of 1550nm

  

  Advantages of BiDi Transceivers

  The obvious advantage of utilizing BiDi transceivers, such as SFP+- BiDi and SFP-BiDi transceivers, is the reduction in fiber cabling infrastructure costs by reducing the number of fiber patch panel ports, reducing the amount of tray space dedicated to fiber management, and requiring less fiber cable.

  While BiDi transceivers (a.k.a. WDM transceivers) cost more to initially purchase than traditional two-fiber transceivers, they utilize half the amount of fiber per unit of distance. For many networks, the cost savings of utilizing less fiber is enough to more than offset the higher purchase price of BiDi transceivers.

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