2017年3月31日星期五

(VIDEO)The Details introduction of fbier optic connector

The Details introduction of fbier optic connector 

About FIBER-MART(Fiber-MART.COM)


FIBER-MART(Fiber-MART.COM), based in HongKong & U.S., a worldwide leading supplier in fiber optic network, fttx, fiber cabling & connectivity, fiber testing, fiber splicing, fiber polishing & integrated network solutions. Devoting on the research & development, design, manufacture, and fiber connectivity network solutions for carriers, ISPs, content providers and networks, has always engaged in high-performance and innovation.

Our goal is to create value for worldwide customers continuously with high-quality products and excellent services in the field of optical communication.

With last four years growing, FIBER-MART(Fiber-Mart.com) has built its strong and professional teams in optical communication product R&D, systematic solution and supply chain management.

FIBER-MART(Fiber-Mart.com) focuses on the high-performance all the time, which highlights the pertinent best practices and benefits of managing quality as an integrated part of business to build a culture of collaboration and innovation. All the products from FIBER-MART(Fiber-Mart.com) are tested individually and walk through the testing challenges. We set ourselves apart by investing in highly trained technical staff and state-of-the-art testing facilities to ensure the products consistency and reliability. Our quality control procedures are designed to ensure virtually zero chance of failure in your network. The advanced and powerful inventory & warehouse management system established by FIBER-MART(Fiber-Mart.com) ensures the delivery capacity and quick response speed.

Nowadays, FIBER-MART(Fiber-Mart.com) is doing business with more and more worldwide well-known corporations like CloudFlare, EXFO, Apple, MRV, JDSU, ADTRAN, Avago, EMC, etc., who have put large volume of FIBER-MART(Fiber-Mart.com)’s products into production for their Data Center or Cloud Computing application and speak highly of our service and products.

(VIDEO)How to install 10 Gigabit SFP transcievers & fiber optic links between switches

ow to install 10 Gigabit SFP transcievers & fiber optic links between switches

FIBER-MART(Fiber-MART.COM), based in HongKong & U.S., a worldwide leading supplier in fiber optic network, fttx, fiber cabling & connectivity, fiber testing, fiber splicing, fiber polishing & integrated network solutions. Devoting on the research & development, design, manufacture, and fiber connectivity network solutions for carriers, ISPs, content providers and networks, has always engaged in high-performance and innovation.

Our goal is to create value for worldwide customers continuously with high-quality products and excellent services in the field of optical communication.

 FIBER-MART(Fiber-Mart.com) focuses on the high-performance all the time, which highlights the pertinent best practices and benefits of managing quality as an integrated part of business to build a culture of collaboration and innovation. All the products from FIBER-MART(Fiber-Mart.com) are tested individually and walk through the testing challenges. We set ourselves apart by investing in highly trained technical staff and state-of-the-art testing facilities to ensure the products consistency and reliability. Our quality control procedures are designed to ensure virtually zero chance of failure in your network. The advanced and powerful inventory & warehouse management system established by FIBER-MART(Fiber-Mart.com) ensures the delivery capacity and quick response speed.

Nowadays, FIBER-MART(Fiber-Mart.com) is doing business with more and more worldwide well-known corporations like CloudFlare, EXFO, Apple, MRV, JDSU, ADTRAN, Avago, EMC, etc., who have put large volume of FIBER-MART(Fiber-Mart.com)’s products into production for their Data Center or Cloud Computing application and speak highly of our service and products.

2017年3月30日星期四

How to definite the Fiber Media Converter?

How to definite the Fiber Media Converter?
Fiber Media Converter


A converter, also called a transceiver, is a device comprises both atransmitter and a receiver which are combined and share common circuitry or a single housing. When no circuitry is common between transmit and receive functions, the device is a transmitter-receiver. The term originated in the early 1920s. Technically, transceivers must combine a significant amount of the transmitter and receiver handling circuitry .
 
Fiber media converter, also known as fiber transceivers or Ethernet media converters, are simple networking devices that make it possible to connect two dissimilar media types such as twisted pair such as Cat 5 or Cat 6 cable with fiber optic cabling. To be plainer, they receive data signals, sent via one media, convert the signals and then transmit the signals into another. Fiber optic media converters can convert the signals sent from copper cable to signals that run on the fiber cable. They are copper to fiber or fiber-to-fiber conversion devices. They are important in interconnecting fiber optic cabling-based systems with existing copper-based, structured cabling systems. Fiber Ethernet media converters support a variety of communication protocols including Ethernet, Fast Ethernet, fiber media converter gigabit. There are single mode converter and multi-mode converters. For single mode converter, there are dual fiber type and single fiber type, in which the fiber cable functions both as transmitting media and receiving media. While for multi-mode converter, there are only dual fiber types. Single fiber media converters are also called WDM fiber optic converters.
 
Fiber media converter can connect different Local area network (LAN) media, modifying duplex and speed settings. For example, switching media converters can connect legacy 10BASE-T network segments to more recent 100BASE-TX or 100BASE-FX Fast Ethernet infrastructure. For another, existing Half-Duplex hubs can be connected to 100BASE-TX Fast Ethernet network segments over 100BASE-FX fiber. When expanding the reach of the LAN to span multiple locations, fiber transceivers are useful in connecting multiple LANs to form one large campus area network that spans over a wide geographic area.
 
Our fiber media converters are designed to meet the needs for massive fiber network deployment and able to extend a legacy copper based Ethernet network via fiber optic cable to a maximum distance up to100Km. It is fully compliant with IEEE802.3u standards, support bi-directional transmission of 10/100/1000MFast IP Ethernet data or over one multi-mode or single-mode fiber. We can offer compact, cost-effective, low dissipative, high reliable and stable fiber media converter which can be used in standalone applications, or Rack-Mounted applications where multiple media converters can be inserted into a rack-mount chassis (up to 16 units), and allowing all the converters to be powered by a single internal power supply.

About FIBER-MART(Fiber-MART.COM)


FIBER-MART(Fiber-MART.COM), based in HongKong & U.S., a worldwide leading supplier in fiber optic network, fttx, fiber cabling & connectivity, fiber testing, fiber splicing, fiber polishing & integrated network solutions. Devoting on the research & development, design, manufacture, and fiber connectivity network solutions for carriers, ISPs, content providers and networks, has always engaged in high-performance and innovation.

Our goal is to create value for worldwide customers continuously with high-quality products and excellent services in the field of optical communication.

The Right way to Test Hardware by Loopback Cables

The Right way to Test Hardware by Loopback Cables
Fiber loopback cables
Fiber loopback cables 


Fiber loopback cables provide system test engineers a simple but effective way of testing the transmission capability and receiver sensitivity of network equipment. The hardware loopback plug test is used to see if the router has any faults. If a router passes a hardware loopback plug test, then the problem exists elsewhere on the line. When a serial line does not come up as it must, the best way to troubleshoot the circuit is to perform loopback tests. Loopback tests allow you to isolate pieces of the circuit, and test them separately. Begin loopback tests on the customer premises with channel service unit/data service unit (CSU/DSU) loopback tests. Then proceed on to loopback tests that involve the telco or provider. Two kinds of loopback tests can be used to isolate problems on the serial link: software loopbacks and hardware plug loopbacks. Whether it is an internal or external CSU/DSU, you can do both software and hardware loopbacks back towards the router.Software local loopbacks are usually implemented with a Cisco IOS configuration command, or with a loopback button for some CSU/DSUs. A loopback plug or cable inserted into the CSU/DSU can be used for hardware loopbacks.If CSU/DSU loopback tests prove that the router equipment, CSU/DSU, and connecting cables are not faulty, conduct further tests with the telco or provider of the circuit.
 
There are several types of fiber loopback cables, such as LC, SC, FC, MTRJ. The LC fiber optic loopback cables are used in test applications LC fiber optic loopback cable connector feature the RJ-45 style interface with low insertion loss and low back reflection, it is with high precision alignment and is widely used all over the world. LC loopback cables can be 9/125 single mode or 50/125 multimode or 62.5/125 multimode. The LC fiber loopback cable connector is with a 1.25mm O.D zirconia ceramic ferrule and it is compliant to Telcordia, EIA/TIA and IEC standards. LC loopback cables are designed for testing, engineering and the burn-in stage of boards or other equipment. One connector is plugged into the output port, while the other is plugged into the input port of the equipment.
 
Fiber-mart.com supply loopbacks which are precision terminated and feature extremely low loss characteristics for transparent operation in the test environment and in form of cable and module types. 10G OM3, Singlemode and Multimode fiber optic loopback modules are available.

About FIBER-MART(Fiber-MART.COM)


FIBER-MART(Fiber-MART.COM), based in HongKong & U.S., a worldwide leading supplier in fiber optic network, fttx, fiber cabling & connectivity, fiber testing, fiber splicing, fiber polishing & integrated network solutions. Devoting on the research & development, design, manufacture, and fiber connectivity network solutions for carriers, ISPs, content providers and networks, has always engaged in high-performance and innovation.

Our goal is to create value for worldwide customers continuously with high-quality products and excellent services in the field of optical communication.

Do you choose the Right Fiber Optic Adapters?

Do you choose the Right Fiber Optic Adapters?

Today, fiber-mart.com would like to introduce one of small but very important accessory in the fiber cabling field, the fiber optic adapter.
 
The fiber optic adapters are commonly used in the fiber optic connection field. They are used to provide a cable to cable or cable to equipment fiber optic connection. Through some many years of develop, now these fiber optic adapters have many different shapes but still all serve the same purpose, it allows the optical fiber cables to be connected to each other singly or in a large network which allowing many devices to communicate at once. While in this two types of using, the use of simply to connect two fiber optic cables to one another is the most common uses. By connecting two cables together can allow two devices to communicate from a distance through a direct connection with the fiber-optic line.
 
fiber-mart.com now can supply a number of different shapes of adapters. For the flange fiber optic adapters we provide, it is always be used to connect the cables which are all of the same shape. It includes many varieties such as FC, SC, ST, LC, MTRJ, SMA, DIN, MU, MPO and E2000. And even for the FC-FC fiber optic adapter, it have many types such as the Round Big D type, Round Small D type, Square solid type (one piece), (Square two pieces type), screw panel mount and so on. While for the hybrid fiber optic adapters, it is always used for the connection of two cables that are different shapes. A hybrid connector can be designed to fit any two types of fiber optic cables together, there are many different types of hybrid connectors. For example, the LC female to SC male single-mode fiber adapter, the LC female to FC male fiber adapter, the FC female to SC male fiber coupler, the FC to ST fiber optic adapter, SC to ST Duplex fiber optic adapters…And the third types of fiber optic adapters is the bare fiber optic adaptor, it allow users to make fast connection of the bare fiber and the fiber optic equipment, bare fiber optic adaptors can be used in some emergency situation for urgent connection. So much for the introduction of the fiber optic cable adapters, welcome to buy these high quality while low price fiber optic connection products on our website.

About FIBER-MART(Fiber-MART.COM)



FIBER-MART(Fiber-MART.COM), based in HongKong & U.S., a worldwide leading supplier in fiber optic network, fttx, fiber cabling & connectivity, fiber testing, fiber splicing, fiber polishing & integrated network solutions. Devoting on the research & development, design, manufacture, and fiber connectivity network solutions for carriers, ISPs, content providers and networks, has always engaged in high-performance and innovation.

Our goal is to create value for worldwide customers continuously with high-quality products and excellent services in the field of optical communication.

2017年3月29日星期三

What And How To Use Digital Optical Connection

What And How To Use Digital Optical Connection

Definition of a Digital Optical Connection
 
digital optical connection is a type of connection that uses light (fiber optics) to transfer audio data digitally from a compatible source device to a compatible playback device. The audio data is converted from electrical pulses to light pulses on the transmission end, and then back to sound pulses on the receiving end.
 
Contrary to popular belief, the light is not generated by a laser - but is generated by a small LED light source on the transmission end, which can be sent through the fiber optical cable to a compatible connection on the receiving end.
 
 
Digital Optical Connection Applications
In home audio and home theater, Digital Optical connections are used for transferring specific types of digital audio signals.
 
Devices that may provide this connection option include DVD players, Blu-ray Disc players, Media Streamers, Cable/Satellite Boxes, Home Theater Receivers, and, in some cases CD players and newer Stereo Receivers.
 
The types of digital audio signals that can be transferred by a Digital Optical Connection include two-channel stereo PCM, Dolby Digital, Dolby Digital EX, DTS Digital Surround, and DTS ES.
 
It is important to note that digital audio signals, such a 5.1/7.1 channel PCM, Dolby Digital Plus, Dolby TrueHD, Dolby Atmos, DTS-HD Master Audio, and DTS:X cannot be transferred via Digital Optical connections - These formats require HDMI connections.
 
The reason for this difference is that when the Digital Optical connections was developed, it was made to comply with digital audio standards at the time, which did not include 5.1/7.1 channel PCM, Dolby Digital Plus, Dolby TrueHD, Dolby Atmos, DTS-HD Master Audio, or DTS:X.
 
In other words, Digital Optical cables do not have the bandwidth capability to handle some newer home theater surround sound formats.
 
It is also important to point out that, as of 2015, although all Home Theater Receivers, DVD player, most Media Streamers, Cable/Satellite Boxes, and even some Stereo Receivers have a Digital Optical connection option, there are some Blu-ray Disc players that eliminated Digital Optical connection as one of the audio connection options, opting for an HDMI output only connection for both audio and video.
 
In other words, if you have a home theater receiver that has the Digital Optical connection option, but does not provide the HDMI connection option, make sure that when you are shopping for a newer Blu-ray Disc player, that it does, indeed offer, a Digital Optical connection option for audio.
 
NOTE: Digital Optical Connections are also referred to as TOSLINK (which is short for Toshiba Link). connections.

What Is a Fiber Optic Cable?

What Is a Fiber Optic Cable?

fiber optic cable is a network cable that contains strands of glass fibers inside an insulated casing. They're designed for long distance, very high performance data networking and telecommunications.
 
Compared to wired cables, fiber optic cables provide higher bandwidth and can transmit data over longer distances.
 
Fiber optic cables support much of the world's internet, cable television and telephone systems.
 
How Fiber Optic Cables Work
Fiber optic cables carry communication signals using pulses of light generated by small lasers or light-emitting diodes (LEDs).
 
The cable consists of one or more strands of glass, each only slightly thicker than a human hair. The center of each strand is called the core, which provides the pathway for light to travel. The core is surrounded by a layer of glass called cladding that reflects light inward to avoid loss of signal and allow the light to pass through bends in the cable.
 
The two primary types of fiber cables are called single mode and multi mode fiber. Single mode fiber uses very thin glass strands and a laser to generate light while multi mode fibers use LEDs.
 
Single mode fiber networks often use Wave Division Multiplexing (WDM) techniques to increase the amount of data traffic that can be sent across the strand.  WDM allows light at multiple different wavelengths to be combined (multiplexed) and later separated (de-multiplexed), effectively transmitting multiple communication streams via a single light pulse.
 
Advantages of Fiber Optic Cables
Fiber cables offer several advantages over traditional long-distance copper cabling.
 
Fiber optics have a higher capacity. The amount of network bandwidth a fiber cable can carry easily exceeds that of a copper cable with similar thickness. Fiber cables rated at 10 Gbps, 40 Gbps and even 100 Gbps are standard.
 
Since light can travel much longer distances down a fiber cable without losing its strength, it lessens the need for signal boosters.
Fiber is less susceptible to interference. A traditional network cable requires special shielding to protect it from electromagnetic interference. While this shielding helps, it is not sufficient to prevent interference when many cables are strung together in close proximity to each other. The physical properties of glass and fiber cables avoid most of these issues.
Fiber to the Home (FTTH), Other Deployments, and Fiber Networks
Whereas most fiber is installed to support long distance connections between cities and countries, some residential internet providers have invested in extending their fiber installations to suburban neighborhoods for direct access by households. Providers and industry professionals call these "last mile" installations.
 
Some better known FTTH services in the market today include Verizon FIOS and Google Fiber. These services can provide gigabit (1 Gbps) internet speeds to each household. However, even though providers also offer lower cost, they typically also offer lower capacity packages to their customers.
 
FTTP (Fiber to the Premises): Fiber that's laid all the way up to the building.
FTTB (Fiber to the Building/Business/Block): The same as FTTP.
FTTC/N (Fiber to the Curb of Node): Fiber that's laid to the node but then copper wires complete the connection inside the building.
Direct fiber: Fiber that leaves the central office and is attached directly to one customer. This provides the greatest bandwidth but is more expensive.
Shared fiber: Similar to direct fiber except that as the fiber gets close to the premises of nearby customers, it's split into others fibers for those users.
What Is Dark Fiber?
The term dark fiber (often spelled dark fibre or called unlit fibre) most commonly refers to installed fiber optic cabling that is not currently being used.
 
It sometimes also refers to privately operated fiber installations.

How a fiber-optic cable could forever change life

How a fiber-optic cable could forever change life

Summer construction on the first fiber-optic cable to cross the Arctic has rural Alaska telecom providers promising a huge market shift in a region that is on the underserved side of the digital divide.
 
As two ships unspool cable onto the floor of the Bering and Chukchi seas, consumers in six coastal communities from Nome to Barrow anticipate cheaper, speedier internet and the ability to download more data without overage charges by the middle of next year.
 
The economics of bringing internet to rural Alaska are lousy, which is why the federal government, through various programs, subsidizes connectivity. And even then, rural consumers pay high rates for plans with low data limits and download speeds.
 
But these communities — Nome, Kotzebue, Point Hope, Wainwright, Barrow and the oil industry work camps at Prudhoe Bay — happen to be along the path of a fiber-optic line, financed by one of the world's richest men, to connect the global financial hubs of London and Tokyo.
 
The project run by Quintillion Subsea Operations is notable in many ways. If completed, it would take the first fiber-optic cable through the Northwest Passage. It would significantly shave trading times between stock markets in Europe and Asia and presumably make subscription a must for financial institutions and high-speed traders, who operate in a world where milliseconds can be worth millions.
 
And it's being quietly backed by Leonard Blavatnik, whose global conglomerate Access Industries owns companies in plastics, oil and gas, fashion, telecom, tech, entertainment and real estate. Blavatnik's Warner Music Group owns the record labels of Bruno Mars, Blake Shelton and Coldplay. As of Sept. 1, Forbes' real-time wealth ranking listed Blavatnik as the world's 58th richest person, with a net worth of $15.6 billion.
 
But what matters most to consumers in the path of Blavatnik's history-making project is the prospect of solid internet connections with more speed and data that cost less than what regional telecom companies can provide through the satellite and microwave systems currently in place.
 
Sarah Bernick, the pastor's wife and Sunday school teacher at Bible Baptist Church in Wainwright, said her household pays $120 a month for a plan through Arctic Slope Telephone Cooperative Association. But she still uses the more reliable connection at the school to make important transactions online.
 
"They don't guarantee service or speed and the service goes out pretty frequently," Bernick said. "All of a sudden for a day we don't have internet and sometimes they have to fly a service person up here."
 
She called the internet "a lifeline," used heavily in the village of about 600 people for buying groceries, clothes, household appliances and, because there is no local bank, paying friends and neighbors for goods and services through account transfers.
 
In Nome, the fiber, encased in copper, steel and polyethylene, comes ashore about 2 miles outside town on the Nome-Council Road. The line snakes past corroded gold-mining equipment, down dirt alleys — to avoid water and sewer lines — and under the wood siding of the TelAlaska building, where equipment to run and power the cable now shares space with every phone line in the city of 3,800 people.
 
Outside St. Joseph Catholic Church in late August, a crew with an excavator and shovels placed a final section of cable overlaid with red warning tape.
 
Quintillion is entering territory held by GCI, the state's dominant telecom company, whose TERRA network provides broadband connections via microwave towers to 72 communities in rural Alaska. TERRA relies heavily on federal subsidies either directly or through programs such as the Universal Service Fund, which essentially gives schools and libraries a discount on communications services by compensating vendors. (TERRA stands for Terrestrial for Every Rural Region in Alaska.)
 
The two companies say there is plenty of business to go around. Martin Cary, senior vice president of business services at GCI, insists that Quintillion will not significantly affect market share.
 
He noted that Quintillion is focused on hub communities, with the exception of Wainwright and Point Lay, whereas GCI serves a much wider group of villages.
 
"Quintillion is not picking up any of the villages, they're just picking up regional centers and that's not a solution for the school districts and for the health corporations because their primary customers are in their villages, which is where we focus — putting complete solutions together for our anchor tenant customers."
 
GCI recently began expanding into Noorvik and Golovin. Construction in Buckland will begin once permitting is complete, according to a GCI press release Friday. The company expects to have TERRA in 84 communities by the end of 2016.
 
Arctic telecom providers are optimistic overall that Quintillion will expand choice and competition, improve service and potentially lower prices.

2017年3月28日星期二

Only Connect: On fibre optic connectors fiber-mart.com


This week I am going to give you an overview of common fibre optic connectors in use today. I get asked a lot about which connectors to use and the following guide should give you an idea of what is out there and is best suited to your application.
I have also spoilt you with a video guide at the bottom of this guide!

MT-RJ

Used for networking applications. It’s actually a little smaller than a standard phone jack, and just as easy to connect and disconnect. It’s half the size of the SC connector and it was designed to replace LC Connectors but that is yet to happen.

FDDI

Used for networking applications. Duplex connector with fixed shroud, keyed.

ESCON

Used for Data and Voice network applications (Duplex).

ST

One of the most commonly used fibre optic connectors in networking applications. Cylindrical with twist lock coupling, 2.5mm keyed ferrule. For both short distances applications and long line systems.

SC

Used frequently for newer network applications. Square, keyed connector with push-pull mating, 2.5mm ferrule and moulded housing for protection.

SMA

The SMA fibre connector is decreasing in popularity. Used mainly in Electronics.

Biconic

Decreasing in use. Used in the medical device industries.

LC

By far the most popular connector used in the IT industry. It has been around for years and has no signs of going away anytime soon. It is simple and easy so likely to still be in use for years to come.

MU Connector

This simplex connector is not as popular as LC connectors are. This is because LC Connectors are able to be used as simplex connectors and more widely available.

Toslink Connector

Used in Hi-Fi and Audio Products. Delivering the highest quality of audio signal available but also simple, robust and very inexpensive.
With Fibre Optics there is much more than just the connectors as the cable is also a massive subject on its own so watch out for future blogs on the subject.
Finally, here is the video I promised you, enjoy:

Introduction of Fiber-Optic Connector Technology for O&G Ops


Fiber-optics (FO) technology is finding new uses in subsea applications. Fiber allows longer transmission distances and higher data rates than copper — a fortuitous development, as offshore drilling moves to deeper depths. Petroleum exploration and production are also becoming smarter, as operators pursue real-time information and analysis of both the individual well and the entire production chain from well to topside or land-based platform. Compared to copper, the high bandwidth of fiber allows richer data streams and much longer step-out distances (i.e., distance between subsea installation and surface facilities). Umbilical cables can easily reach lengths of 10-15 km, while pipeline cables, used for sensing, can extend to 40 km.

Optical fibers also make superior distributed sensors. Changes in pressure or temperature modify the backscatter profile, allowing highly accurate measurements by monitoring the backscattered light. Because the velocity of light in a fiber is well understood, the backscattered light reveals information on both the magnitude of measurement and its location along the length of the fiber. 

Since each fiber is smaller and more capable than a copper cable, the number of fibers an umbilical cable can accommodate is also increasing, from a dozen or fewer today to 24 or even 48 fibers in the near future. Figure 1 shows the TE Connectivity’s (TE) SEACON 24/48 channel HydraLight wetmate connector for optical subsea distribution systems.

Such advances in technology have increased interest in optical connectivity. Subsea connectors, for either copper or fiber cables, face an extremely harsh operating environment characterized by high pressure, temperature extremes and corrosion-friendly seawater. Despite operating in such adverse working conditions, a connector must be absolutely reliable throughout its design life of 25-30 years.

On one side of the equation, industry requires growing fiber count, and on the other side lower cost and higher reliability. The objective is to have a connector that is well-balanced between these seemingly “opposite” requirements. This is the reason why FO connector designers continuously innovate in terms of design and integrated optical technology. In the new offshore oil and gas market environment, they are committed to bringing FO connector capability and cost-effectiveness as close to each other as possible.

Drymate connectors are familiar to users of military/aerospace circular connectors. FO drymate connectors can be installed either within a module or between modules that have been assembled on-site. They are designed for topside mating in an atmospheric environment, although they withstand subsea water and pressures while mated. The standard coupling of each half – ensuring sealing integrity of the mated pair; is performed manually via a threaded coupling ring. 

In subsea FO wetmate technology, typified in the second-generation HydraLight connector, the crucial fiber-to-fiber underwater union is accomplished while both halves of the FO termination are protected from contamination by seawater, sand and silt, because the mating process occurs in an enclosed, separate, oil-filled, pressure-balanced chamber. This pressure balancing system allows the connector to operate without being affected by the pressure, in contrast to most drymate connectors, which have to withstand pressure differential due to having an atmospheric-pressure internal cavity.

Smaller systems benefit from fiber optics. More compact, lighter, highly modular subsea drilling and production systems are the order of the day. They are easier and less expensive to install. Even though an optical fiber weighs much less than a comparable copper wire, there are practical limits to how small a connector should be. A subsea wetmate connector that will be deployed by a remotely operated vehicle (ROV) must be large enough to be clearly seen by ROV cameras, and sufficiently robust to be mated/unmated without damage by ROV manipulators. In this case, ROV-mateable connectors may have generous lead-ins to guide the mating halves together.

Connecting Traditional Packaging to Subsea Applications
To a great extent, subsea fiber optic connectors use new ways of packaging tried-and-true technologies, rather than radically new and unproven approaches. TE Connectivity Marine Oil & Gas adapts technologies that were well-established for telecom, network, aerospace and military applications to subsea applications. Subsea connector technology relies on ultra physical contact (UPC) and, more recently, angled physical contact (APC) for better performance (especially with sensing systems) of termini based on a ceramic ferrule, a well-understood technology dating back 40 years and the beginning of fiber optics.

During the last decade, alternative optical connectivity technologies have been developed and proved their reliability from both manufacturing and application perspectives. Some approaches use a non-contacting interface to provide higher durability and tolerance to rough handling, with a small penalty in optical performance. Others provide a high-density, multi-fiber connection to save space and weight for high-fiber-count systems, at the expense of some complexity at the connecting interface and pre-alignment mechanism.

In another interesting connectivity technology development, a bare fiber cleaved tip has been repackaged into a downhole wetmate connector. This epoxy-free and ferrule-less technology offers both greater tolerance to high temperature and a lower-profile dimension in order to fit into a tight downhole casing. Figure 2 shows FO wetmate connectors developed for subsea trees and downhole applications.

Depending on the subsea and marine application and type of sensing required, each of these optical-interface technologies has its place. The main challenge is to adapt these technologies optimally, in order to create a cost-effective solution meeting installation, deployment and maintenance needs.

Industry needs connectors to function reliably when installed subsea and downhole in a well for reservoir surveillance and improved oil recovery. High-temperature wells (e.g., >150°C), where electrical sensing systems face some limitations, were targeted early on for deployment of FO sensing systems. Over the years, FO sensing gained interest among operators, not only for the ability to withstand very high temperatures, but also for the quality and the amount of data retrievable from the wells.

Most operators introduce next-level FO capabilities as part of a natural progression in their field development. As marine oil and gas exploration and production venture to ever-increasing depths, with consequently more robust fiber-optic connector operating pressure and temperature requirements, industry challenges evolve to keep pace, and a collaborative approach with customers and partners is key for subsea FO connectivity design. It is always desirable to exceed technical requirements, but it is much more important to exceed customer expectations in term of cost, operability and reliability.

Future Implications
Long transmission distances, high data rates, lightweight, small size, distributed sensing—fiber optics brings together so many capabilities important to improve efficiency of marine offshore exploration and production. The technological breakthroughs of optical fiber connectivity can create a bright future with the possibility of developing and producing with higher performance at lower cost and unlocking new resources. 

2017年3月27日星期一

What's the Evolution to flexible grid WDM from fiber-mart.com

WDM networks operate by transmitting multiple wavelengths, or channels, over a fiber simultaneously. Each channel is assigned a slightly different wavelength, preventing interference between channels. Modern DWDM networks typically support 88 channels, with each channel spaced at 50 GHz, as defined by industry standard ITU G.694. Each channel is an independent wavelength.
 
The fixed 50-GHz grid pattern has served WDM networks and the industry well for many, many years. It helps carriers easily plan their services, capacity, and available spare capacity across their WDM systems. In addition, the technology used to add and drop channels on a ROADM network is based on arrayed-waveguide-grating (AWG) mux/demux technology, a simple and relatively low-cost technique particularly well suited to networks based on 50-GHz grid patterns.
 
WDM networks currently support optical rates of 10G, 40G, and 100G per wavelength (with the occasional 2.5G still popping up), all of which fit within existing 50-GHz channels. In the future, higher-speed 400-Gbps and 1-Tbps optical rates will be deployed over optical networks. These interfaces beyond 100G require larger channel sizes than used on current WDM networks. The transition to these higher optical rates is leading to the adoption of a new, flexible grid pattern capable of supporting 100G, 400G, and 1T wavelengths.
 
Current generation
 
The fixed 50-GHz grid pattern specified by ITU standards is shown in Figure 1. Any 10G, 40G, or 100G optical service can be carried over any of the 50-GHz channels, which enables carriers to mix and match service rates and channels as needed on their networks.
A look inside each channel reveals some interesting differences between the optical rates and resulting efficiency of the optical channel . A 10G optical signal easily fits within the 50-GHz-channel size, using about half the available spectrum. The remaining space within the 50-GHz channel is unused and unavailable. Meanwhile, the 40G and 100G signals use almost the entire 50-GHz spectrum.
 
Spectral efficiency is one measure of how effectively or efficiently a fiber network transmits information and is calculated as the number of bits transmitted per Hz of optical spectrum. With 10G wavelengths the spectral efficiency is only 0.2 bit/Hz, while the 100G wavelength provides a 10X improvement in spectral efficiency to 2 bits/Hz. The more bits that can be transmitted per channel, the greater the improvement in spectral efficiency and increase in overall network capacity and the lower the cost per bit of optical transport.
 
While 100G wavelengths are becoming more common, carriers are already planning for higher-speed 400G and 1T channels on their future ROADM networks, with the expectation that spectral efficiency will at least remain the same, if not improve. New ways of allocating bandwidth will be needed to meet these expectations.
 
Superchannels
 
As mentioned, WDM networks currently transmit each 10G, 40G, and 100G optical signal as a single optical carrier that fits within a standard 50-GHz channel. At higher data rates, including 400G and 1T, the signals will be transmitted over multiple subcarrier channels . The group of subcarrier wavelengths is commonly referred to as a "superchannel." Although composed of individual subcarriers, each 400G superchannel is provisioned, transmitted, and switched across the network as a single entity or block.
 
While 400G standards are still in preliminary definition stage, two modulation techniques are emerging as the most likely candidates: dual polarization quadrature phase-shift keying (DP-QPSK) using four subcarriers and DP-16 quadrature amplitude modulation (QAM) with two subcarriers. Due to the differences in optical signal-to-noise-ratio requirements, each modulation type is optimized for different network applications. The 4×100G DP-QPSK approach is better suited to long-haul networks because of its superior optical reach, while the 2×200G DP-16QAM method is ideal for metro distances.
 
Since 400G signals are treated as a single superchannel or block, the 400G signals shown in Figure 3 require 150-GHz- and 75-GHz- channel sizes, respectively. It's this transition to higher data rates that leads to the requirement for and adoption of new flexible grid channel assignments to accommodate mixed 100G, 400G, and 1T networks.
 
A new flexible grid pattern has been defined and adopted by ITU G694.1. While commonly referred to as "gridless" channel spacing, in reality the newly defined flexible channel plan is actually based on a 12.5-GHz grid pattern. The new standard supports mixed channel sizes, in increments of n×12.5 GHz and easily accommodates existing 100G services (4×12.5 GHz = 50 GHz) and future 400G (12×12.5 GHz) and 1T optical rates.
 
One of the advantages of the flexible grid pattern is the improvement in spectral efficiency enabled by more closely matching the channel size with the signals being transported and by improved filtering that allows the subcarriers to be more closely squeezed together. As shown in Figure 5, four 100G subcarriers have been squeezed into 150-GHz spacing, as opposed to the 200 GHz (4×50 GHz) required if the subcarriers were transported as independent 50-GHz channels. The net effect of the flexible channel plan and closer subcarrier spacing is an improvement in network capacity of up to 30%.
 
One common "myth" in the industry is that legacy networks must be upgraded, or "flexible grid-ready," to support 400G optical rates and superchannels. While having flexible grid-capable ROADMs can improve spectral efficiency, they're not a requirement to support 400G or superchannels on a network. Since the subcarriers are fully tunable to any wavelength, they can simply be tuned to the existing 50-GHz grid pattern, allowing full backward compatibility with existing ROADM networks.
 
CDC ROADMs
 
Closely associated with flexible grid channel spacing are colorless/directionless/gridless (CDG) and colorless/directionless/contentionless/gridless (CDCG) ROADM architectures. Along with gridless channel spacing, CDC ROADMs enable a great deal of flexibility at the optical layer.
Recall that existing ROADM systems are based on fixed 50-GHz-channel spacing and AWG mux/demux technology. The mux/demux combines and separates individual wavelengths into different physical input and output ports. While the transponder and muxponder themselves are full-band tunable and can be provisioned to any transmit wavelength, they must be connected to a specific port on the mux/demux unit. A transponder connected to the west mux/demux only supports services connected in the west direction. To reassign wavelengths – either to new channels or to reroute them to a different direction – requires technician involvement to physically unplug the transponder from one port on the mux/demux and plug it into a different physical mux/demux port.
 
CDC ROADMs enable much greater flexibility at the optical layer. The transponders may be connected to any add/drop port and can be routed to any degree or direction. Wavelength reassignment or rerouting can be implemented automatically from a network management system, or based on a network fault, without the need for manual technician involvement. The tradeoffs with CDC ROADMs are more complex architectures and costs.
 
Flexing network muscles
 
The existing 50-GHz-channel plan based on ITU G.694 has served the industry well for many years. But as the industry plans for the introduction of even faster 400G, and eventually 1T, optical interfaces, there's a need to adopt larger channel sizes and a more flexible WDM spacing plan.
 
These higher-speed optical interfaces rely on a new technique involving superchannels that comprise multiple subcarrier wavelengths. These subcarriers are provisioned, transported, and switched across a network as a single block or entity. Flexible grid systems enable the larger channel sizes required by 400G and 1T interfaces, but also allow the channel size to be closely matched to the signal being transported to optimize spectral efficiency.
 
No discussion of gridless ROADMs would be complete without including new next generation CDC ROADM architectures. These new ROADMs will enable a great deal more flexibility and efficiency at the optical layer.