fiber optic coupler Archives - DK Photonics Blog

Comparation Between EPON and GPON

With the continuous progress of science and technology, the Internet has gradually gone into the homes of the ordinary people, and the speed of broadband has increasingly become the topic of people in the entertainment and work often, from narrowband dial-up to broadband Internet, and then the fiber access Internet, broadband network, the rapid pace of PON technology gradually come to the front. Currently, there are two quite compelling PON standard has been officially released, which are GPON standard developed by the ITU / FSAN and EPON standard developed by IEEE 802.3ah working group. PON technology has been no doubt the ultimate solution for the future FTTH era. EPON and GPON who will the dominant FTTH tide has become a new hot debate. What’s the difference between EPON and GPON?

GPON and EPON Differences

Perhaps the most dramatic distinction between the two protocols is a marked difference in architectural approach. GPON provides three Layer 2 networks: ATM for voice, Ethernet for data, and proprietary encapsulation for voice. EPON, on the other hand, employs a single Layer 2 network that uses IP to carry data, voice, and video.

A multiprotocol transport solution supports the GPON structure (Figure 1). Using ATM technology, virtual circuits are provisioned for different types of services sent from a central office location primarily to business end users. This type of transport provides high-quality service, but involves significant overhead because virtual circuits need to be provisioned for each type of service. Additionally, GPON equipment requires multiple protocol conversions, segmentation and reassembly (SAR), virtual channel (VC) termination and point-to-point protocol (PPP).

Figure 1: Diagram showing a typical GPON network.

EPON provides seamless connectivity for any type of IP-based or other “packetized” “communications” (Figure 2). Since Ethernet devices are ubiquitous from the home network all the way through to regional, national and worldwide backbone networks, implementation of EPONs can be highly cost-effective. Furthermore, based on continuing advances in the transfer rate of Ethernet-based transport — now up to 10 Gigabit Ethernet — EPON service levels for customers are scalable from T1 (1.5 Mbit/s) up through 1 Gbit/s.

Figure 2: Diagram showing a typical EPON network.

Upstream Bandwidth

Subtracting the various system run overhead from the total bandwidth of the system uplink transmission is the upstream available bandwidth. It has a great relationship with the number of the ONU contained in the system, DBA (Dynamic Bandwidth Allocation) algorithm polling cycle, the type of bearer services, as well as the various business proportion. EPON and GPON are broadband access technology, hosted business IP data services. Below we will calculate the uplink the beared pure IP services available bandwidth of EPON and GPON that contain 32 ONUs, fiber optic coupler,the case of polling period 750s.

EPON

EPON upstream rate is 1.25 Gbit/s. Because the 8B/10B line coding, each 10bit are 8bit valid data, so its effective upstream transmission bandwidth is 1 Gbit/s. EPON upstream overhead of running the system and its proportion of the total bandwidth are as following:

1. Used for the the burst reception of physical layer overhead: about 3.5%;

2. Ethernet frame encapsulation overhead: about 7.4%;

3. MPCP (Multi-Point Control Protocol) and OAM operation and management of maintenance protocol overhead: about 2.9%;

4. DBA algorithm resulting in the remaining time slots (that is not sufficient to transfer a complete Ethernet frame time slot) wasted: about 0.6%;

5. EPON upstream total overhead is all of the above about 144 Mbit/s, the available bandwidth is about 856 Mbit/s.

GPON

GPON supports a variety of rate levels, has asymmetric rate that downlink is 2.5Gbps or 1.25Gbps, the upgoing is 1.25Gbps or 622 Mbps. NRZ encoding the uplink total bandwidth for 1.244 Gbit/s, GPON upstream overhead of running the system as following:

1. The proportion of its total bandwidth is used for the the burst reception of physical layer overhead: about 2.0%;

2. GEM (GPON encapsulation method) frame and the Ethernet frame encapsulation overhead: about 5.8%;

3. The PLOAM (physical layer operation, management and maintenance) protocol overhead: about 2.1%;

4. Remaining slots of the DBA algorithm introduced the additional encapsulation overhead: about 0.8%.

5. GPON upstream total overhead is all of the above about 133 Mbit/s, the available bandwidth about 1111 Mbit/s.

40/100GbE MPO FIBER OPTIC CONNECTOR – NORTH AMERICA MARKET FORECAST

According to ElectroniCast, 12-fiber single mode MPO connector consumption value will increase 141% per year through 2016…

ElectroniCast Consultants, a leading market research & technology forecast consultancy addressing the fiber optics communications industry, today announced the release of their annual market forecast of the North American consumption of MPO Fiber Optic Connectors used in 40 and 100GbE communication links.

In 2006, the IEEE 802.3 working group formed the Higher Speed Study Group (HSSG) and found that the growth in bandwidth for network aggregation applications was outpacing the capabilities of networks employing link aggregation with 10 Gigabit Ethernet. (The standard was announced in July 2007 and was ratified on June 17, 2010).

Applications such as video, virtualization (cloud computing), switching/routing and convergence are driving the need for bandwidth expansion. We continue on the path of gradually developing of growth (and change) from 1G to 10G to 40G and 100G. For data center (DC) environments operating at 40GbE or 100GbE, fiber optic cabling is generally recommended because its reach supports a wider range of deployment configurations compared to copper solutions.

The capability to choose increased speed will enable networks to play with the 10GbE resources to the access layer allowing 40/100GbE to handle traffic at the aggregation and core layers. In this market research report, ElectroniCast Consultants provides their 2011-2016 forecast and analysis of MPO fiber optic connectors used in North American 40/100GbE optical communication networks.

The 10GbE movement into the data centers will continue; however, “future-proofing” is continuing with an accent (40/100G), which is driven by significant broadband expansion demands, especially in regards to network productivity and operating expenses (OPEX costs).

According to ElectroniCast, 12-fiber multimode MPO patchcord dominate the North American (Mexico, Canada and the United States) 40/100GbE MPO connector marketplace in 2012; however, 12-fiber single mode MPO connector consumption value will increase at the fastest pace of 141% per year through 2016.

According to ElectroniCast, 12-fiber multimode MPO connectors currently dominate the North American 40/100GbE MPO connector marketplace, based on consumption value…

40 and 100 GbE MPO Connector Value

North America Market Share (%) in 2012, by Type

(Source: ElectroniCast Consultants)

DK Photonics – www.dkphotonics.com specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM, Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Relationship Between The Optical Coupler And PLC Splitter

In fact, splitter is named for the function of the device, coulper named for its working principle, splitter may be based coupler, and may be based on the waveguide or the separating element, coupler can be done either the splitter, but also can be done WDM, attenuator.

Optical coupler either split optical signals into multiple paths or combines multiple signals on one path. Optical signals are more complex than electrical signals, making optical couplers trickier to design than their electrical counterparts. Like electrical currents, a flow of signal carriers, in this case photons, comprise the optical signal. However, an optical signal does not flow through the receiver to the ground. Rather, at the receiver, a detector absorbs the signal flow. Multiple receivers, connected in a series, would receive no signal past the first receiver which would absorb the entire signal. Thus, multiple parallel optical output ports must divide the signal between the ports, reducing its magnitude. The number of input and output ports, expressed as an N x M configuration, characterizes a coupler. The letter N represents the number of input fibers, and M represents the number of output fibers. Fused couplers can be made in any configuration, but they commonly use multiples of two (2 x 2, 4 x 4, 8 x 8, etc.). optical coupler

PLC Splitter is a device that split the fiber optic light into several parts by a certain ratio. The simplest couplers are PLC Splitters. These devices possess at least three ports but may have more than 32 for more complex devices.PLC Splitters are important passive components used in FTTX networks. But two kinds of fiber splitters are popular used, one is the traditional fused type PLC Splitter (FBT splitter), which features competitive prices; the other is PLC PLC Splitter, which is compact size and suit for density applications. Both of them have its advantages to suit for different requirement.

PLC Spliiter

PLC Splitter typical parameter include input and output part cable length, splitting ratio, working wavelength and with what kind of fiber optic connectors. Just like fiber patch cable, fiber splitters are usually with 0.9mm, 2mm or 3mm cables. 0.9mm outer diameter cable is mostly used in stainless steel tube package PLC Splitters, while 2mm and 3mm cables are mostly used in box type package fiber splitters. Based on working wavelength difference there are single window and dual window PLC Splitters. And there are single mode fiber splitter and multimode fiber splitter. Typical connectors installed on the PLC Splitters are FC or SC type.

Optical coupler or PLC splitters are available in a selection of styles and sizes to separate or combine light with minimal loss. All couplers are produced employing a proprietary procedure that produces reliable, low-cost devices. They’re rugged and impervious to common high operating temperatures. Couplers can be fabricated with custom fiber lengths or with terminations of any type.

Application of optical communication is still broad prospects

Once the Nortel global leader in fiber optic communications during the Internet bubble in 2000, the money in the acquisition of a large number of optical communications research and the production of small and medium enterprises, the industry has been criticized in the subsequent bankruptcy of Nortel. In fact, Nortel grasp of technology trends, the direction is right, unfortunately, Nortel too hasty, global demand for optical communication was not to such an extent.

But now the situation is very different compared with around 2000. The rapid development of mobile Internet and the widespread popularity of smart mobile terminal equipment, being a huge challenge to the global telecommunications network capacity, transmission speed. The era of “data flood peak to optical communication technology has always been known by the transmission bit of new development opportunities and a huge space. Optical communication technology not only did not fall behind, the contrary, the optical communication industry chain, from fiber optic cable system equipment, terminal equipment to optical devices, a critical period in the comprehensive technology upgrade.

The field of optical communication is a noteworthy event, the National Development and Reform Commission recently organizing the preparation of strategic emerging industries key products and services Guidance Catalogue, which in conjunction with the relevant departments, the optical communication technology and product responsibility and selected emerging industries of strategic focus products.

In fiber optics, including FTTx G.657 optical fiber, broadband long-distance high speed large capacity optical fiber transmission with G.656 optical fiber, photonic crystal fiber, rare earth doped fiber (including ytterbium doped fiber, erbium doped fiber and thulium doped fiber, etc.) the laser energy transmission fiber, and has some special properties of new optical fiber, plastic optical fiber, polymer optical fiber is fully finalists. The upgrade of the fiber optic technology, will bring the data transmission capacity, distance, quality leap.

In the field of fiber access equipment, passive optical network (PON), wavelength division multiplexer (WDM),OLT and ONU on the list. Optical transmission equipment, especially the line rate of 40 Gbit/s, 100Gbit/s large capacity (1.6Tb/s and abobe) DWDM equipment, reconfigurable optical bifurcation Multiplexer (ROADM) wavelength division multiplexing system ran cross-connect (OXC) equipment, large-capacity high-speed OTN optical transport network equipment as well as packetized enhanced OTN equipment, PTN packet transport network equipment also impressively. These products are “broadband China” works to promote a powerful weapon; both long-distance backbone network, metropolitan area network or access network even close to the user’s “last mile” of these products will come in handy.

The major products are classified as strategic emerging industries in the field of optical devices, high-speed optical components (active and passive). This is the core and foundation of the field of optical communication technology, device development, the improvement of integration, function enhancement can bring significantly reduce the cost of system equipment and provide a performance boost.

At the same time, the annual OFC / NFOEC (fiber-optic communications exhibition) will be held in late March in California. This event will showcase the latest technology and research progress of the global optical component modules, systems, networks and fiber optic products, represents a new trend of development of optical communication technology.

100G for ultra-high-speed network technology is the current OFC hot one. 2012 100G technology on a global scale backbone network level scale application of 100G optical network applications will rapidly expand with the 100G device further mature. In the same time, the industry has also increased efforts to develop the 100G optical modules, silicon photonics technology pluggable multi-source agreement 100G CFP MSA CPAK optical module has been available. Outside the backbone network, 100G MAN application is the current one of OFC discussion topic.

The rise of cloud computing brings data center construction boom, 100G technology in the data center is a popular data center for high-speed pluggable optical devices is also a hot topic. Experts believe that photonic technology has a key role to play in the large enterprise data centers, but this is only a start, the size of the new cloud computing data center such as a warehouse, with more than 100,000 servers carrying the computing and storage resources, the required network bandwidth than PB level. These data centers only optical communications technology in order to achieve VCSEL (vertical cavity surface emitting lasers) and multi-mode fiber has played an important role, and will continue to introduce new fiber optic communication technology.

What is a fiber optic coupler?

Fiber optic coupler is used to split the fiber optic light into several parts at a certain ratio. fiber optic coupler are important passive components used in FTTX networks. A fiber-optic splitter is a device that takes a single fiber optics signal and divides it into multiple signals. Fiber optic is a type of technology that uses an optical signal instead of an electrical one to send data from one place to another. The cable is made either of glass or plastic coated in plastic, instead of the copper wire that was commonly used in the past. But two kinds of fiber splitters are popular used, one is the traditional fused type fiber optic coupler (FBT coupler), which features competitive prices; the other is PLC fiber optic coupler, which is compact size and suit for density applications. Both of them have its advantages to suit for different requirement. The use of fiber optic technology has become increasingly popular for several reasons. Fiber optic cables are much less sensitive to electrical interference, marking them more reliable than older types of cabling. They are also able to carry very large amounts of data in comparison with that older systems can handle. This makes them very efficient, despite the facts that there are some drawbacks to the system. The cables require a thicker covering to protect the optical cables and they also need to have repeaters installed to boost the signal strength in order for the system to work, two hindrances to the use of this technology.

Despite the limitations, fiber optics technology is in use for both home and commercial applications. The most common type of fiber optic coupler splits the output evenly, with half the signal going to one leg of the output and half going to the other. It’s possible to get splitters that use a different split ratio, putting a larger amount of the signal to one side of the splitter than the other. The Splitters are identified with a number that represents the signal division, such as 50/50 if the split is even, or 80/20 if 80% of the signal goes to one side and only 20% to the other.

Some types of the fiber optic coupler are actually able to work in either direction. This means that if the device is installed in one way, it acts as a splitter and divides the incoming signal into two parts, sending out two separate outputs. If it is installed in reverse, it acts as a coupler, taking two incoming signals and combing them into a single output. Not every fiber optic coupler can be used this way, but those that can are labeled as reversible or as coupler/splitters.