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Passive optical network (PON) is the vital solution to FTTx. It has three key elements: OLT (Optical Line Terminal), ODN (Optical Distributing Network) and ONU (Optical Network Unit). The ONUs of remote node, office or residence, share one OLT. The EPON ONU and EPON OLT are connected via ODN, which is passive.

The term PON (Passive Optical Network) emphasizes on the passive feature of the ODN. That passive structure offers low cost, and ease to maintenance to the FTTx provider. The popular TDM-PON solutions (GPON, GePON) use an optical power splitter to implement the passive ODNs. A popular implementation of this power splitter is based on PLC (Planar Light Circuit) technology. So, it is referred to as a PLC splitter, or a shorter jargon PLC. In fact, PLC has much wider applications than optical power splitter.

Once the TDM-PON (GPON, GePON) technology has reached its limitations, leading suppliers began to explore the next generation of PON infrastructure. The WDM-PON leverages the WDM (Wavelength Division Multiplex) technologies to implement the ODN. One of the decent designs is Nortel-LG (now LG-Ericsson) injection-locking approach (www.lgericsson.com).

Arguably, a switch to WDM-PON is inevitable, if network providers want to deliver higher bandwidth to the FTTx remote nodes. The GPON Fiber Access with 1x32 splitter configurations only deliver 300M bit rate to the premier site. To deliver the 1G bit rate to the remote note, one 10GPON can only support eight (8) remote notes. That is not cost effective.

So, the more pra ctical question is how to leverage the WDM feature of the ODN. Currently, the well discussed solution is a DWDM, pure WDM-PON. It has many benefits. However, the technology is not mature, leading to higher costs. Besides, it gives up the benefit of the existing TDM-PON solutions.

If we combine the mature, low cost CWDM and TDM-PON technologies together, we may have an affordable solution. The CWDM transceivers can support 2.5G bit rate with very competitive price. The 16-channel CWDM mux/demux module are cost effective. With 1x16 splitters, the CWDM-TDM ODN can support 1x256 splitting ratio, much higher than current 1x64 TDM-PON. With that splitting ratio, the premises sites can still have about 155M bit rate. ]]> https://ameblo.jp/lidadaidaihuacapsule/entry-12032163238.html Thu, 28 May 2015 18:19:32 +0900
A PON is a fiber network that only uses fiber and passive components like splitters and combiners rather than active components like amplifiers, repeaters, or shaping circuits. Such networks cost significantly less than those using active components. The main disadvantage is a shorter range of coverage limited by signal strength. While an active optical network (AON) can cover a range to about 100 km (62 miles), a PON is typically limited to fiber cable runs of up to 20 km (12 miles). PONs also are called fiber to the home (FTTH) networks.

The term FTTx is used to state how far a fiber run is. In FTTH, x is for home. You may also see it called FTTP or fiber to the premises. Another variation is FTTB for fiber to the building. These three versions define systems where the fiber runs all the way from the service provider to the customer. In other forms, the fiber is not run all the way to the customer. Instead, it is run to an interim node in the neighborhood. This is called FTTN for fiber to the node. Another variation is FTTC, or fiber to the curb. Here too the fiber does not run all the way to the home. FTTC and FTTN networks may use a customer’s unshielded twisted-pair (UTP) copper telephone line to extend the services at lower cost. For example, a fast ADSL line carries the fiber data to the customer’s devices.

The typical PON arrangement is a point to multi-point (P2MP) network where a central optical line terminal (OLT) at the service provider’s facility distributes TV or Internet service to as many as 16 to 128 customers per fiber line (see the figure). Optical splitters, passive optical devices that divide a single optical signal into multiple equal but lower-power signals, distribute the signals to users. An optical network unit (ONU) terminates the PON at the customer’s home. The ONU usually communicates with an optical network terminal (ONT), which may be a separate box that connects the PON to TV sets, telephones, computers, or a wireless router. The ONU/ONT may be one device.

In the basic method of operation for downstream distribution on one wavelength of light from OLT to ONU/ONT, all customers receive the same data. The ONU recognizes data targeted at each user. For the upstream from ONU to OLT, a time division multiplex (TDM) technique is used where each user is assigned a timeslot on a different wavelength of light. With this arrangement, the splitters act as power combiners. The upstream transmissions, called burst-mode operations, occur at random as a user needs to send data. The system assigns a slot as needed. Because the TDM method involves multiple users on a single transmission, the upstream data rate is always slower than the downstream rate.

GPON

Over the years, various PON standards have been developed. In the late 1990s, the International Telecommunications Union (ITU) created the APON standard, which used the Asynchronous Transfer Mode (ATM) for long-haul packet transmission. Since ATM is no longer used, a newer version was created called the broadband PON, or BPON. Designated as ITU-T G.983, this standard provided for 622 Mbits/s downstream and 155 Mbits/s upstream.

While BPON may still be used in some systems, most current networks use GPON, or Gigabit PON. The ITU-T standard is G.984. It delivers 2.488 Gbits/s downstream and 1.244 Gbits/s upstream.

GPON uses optical wavelength division multiplexing (WDM) so a single fiber can be used for both downstream and upstream data. A laser on a wavelength (λ) of 1490 nm transmits downstream data. Upstream data transmits on a wavelength of 1310 nm. If TV is being distributed, a wavelength of 1550 nm is used.

While each GPON ONT gets the full downstream rate of 2.488 Gbits/s, GPON uses a time division multiple access (TDMA) format to allocate a specific timeslot to each user. This divides the bandwidth so each user gets a fraction such as 100 Mbits/s depending upon how the service provider allocates it.

The upstream rate is less than the maximum because it is shared with other ONUs in a TDMA scheme. The GPON OLT determines the distance and time delay of each subscriber. Then software provides a way to allot timeslots to upstream data for each user.

The typical split of a single fiber is 1:32 or 1:64. That means each fiber can serve up to 32 or 64 subscribers. Split ratios up to 1:128 are possible in some systems.

As for data format, the GPON packets can handle ATM packets directly. Recall that ATM packages everything in 53-byte packets with 48 for data and 5 for overhead. GPON also uses a generic encapsulation method to carry other protocols. It can encapsulate Ethernet, IP, TCP, UDP, T1/E1, video, VoIP, or other protocols as called for by the data transmission. Minimum packet size is 53 bytes, and the maximum is 1518. AES encryption is used downstream only.

The latest version of GPON is a 10-Gigabit version called XGPON, or 10G-PON. As the demand for video and over the top (OTT) TV services has increased, there is an increasing need to boost line rates to handle the massive data of high-definition video. XGPON serves this purpose. The ITU standard is G.987.

XGPON’s maximum rate is 10 Gbits/s (9.95328) downstream and 2.5 Gbits/s (2.48832) upstream. Different WDM wavelengths are used, 1577 nm downstream and 1270 nm upstream. This allows 10-Gbit/s service to coexist on the same fiber with standard GPON. Optical split is 1:128, and data formatting is the same as GPON. Maximum range is still 20 km. XGPON is not yet widely implemented but provides an excellent upgrade path for service providers and customers.

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EPON

The Institute of Electrical and Electronic Engineers (IEEE) developed another newer PON standard. Based on the Ethernet standard 802.3, EPON 802.3ah specifies a similar passive network with a range of up to 20 km. It uses WDM with the same optical frequencies as EPON ONU. The raw line data rate is 1.25 Gbits/s in both the downstream and upstream directions. You will sometimes hear the network referred to as Gigabit Ethernet PON or GEPON.

EPON is fully compatible with other Ethernet standards, so no conversion or encapsulation is necessary when connecting to Ethernet-based networks on either end. The same Ethernet frame is used with a payload of up to 1518 bytes. EPON OLT does not use the CSMA/CD access method used in other versions of Ethernet. Since Ethernet is the primary networking technology used in local-area networks (LANs) and now in metro-area networks (MANs), no protocol conversion is needed.

There is also a 10-Gbit/s Ethernet version designated 802.3av. The actual line rate is 10.3125 Gbits/s. The primary mode is 10 Gbits/s upstream as well as downstream. A variation uses 10 Gbits/s downstream and 1 Gbit/s upstream. The 10-Gbit/s versions use different optical wavelengths on the fiber, 1575 to 1580 nm downstream and 1260 to 1280 nm upstream so the 10-Gbit/s system can be wavelength multiplexed on the same fiber as a standard 1-Gbit/s system.

Summary

Telecommunications companies use PONs to provide triple-play services including TV, VoIP phone, and Internet service to subscribers. The benefit is much higher data rates that are essential to video distribution and other Internet services. The low cost of passive components means simpler systems with fewer components that fail or require maintenance. The primary disadvantage is the shorter range possible, commonly no more than 20 km or 12 miles. PONs are growing in popularity as the demand for faster Internet service and more video grows. GPON is the most popular in the U.S., such as Verizon’s Foist system. EPON systems are more prevalent in Asia and Europe. ]]> https://ameblo.jp/lidadaidaihuacapsule/entry-12031726198.html Wed, 27 May 2015 16:27:53 +0900
For network operators looking to deploy FTTP there are multiple factors that need to be taken into account when planning an installation. These include:

Topography
Regulation
Technical choices
Implementation cost
The need to future-proof investment
Every deployment is different. Therefore to help network operators make the right choices for their implementation we’ve created the Complete Guide to Fiber to the Premises Deployment eBook. Which is available as a free download here. Over the next few months we’ll summarise some of the key points of the guide in a series of blog posts, beginning with fiber architectures.

Passive Optical Networking

In a Passive Optical Networking architecture the operator deploys an Optical Line Terminal (OLT) in the Point of Presence (POP) or central office. One fiber runs to the passive optical splitter and a fan-out connects a maximum of 64 end users with each having an Optical Networking Unit (ONU) at the point where the fiber terminates.

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Point to Point Architecture

In contrast, a Point to Point (P2P) architecture is more complex. It has a core switch at the central office, which connects over optical fiber cables to an aggregation switch at the distribution point, typically located at a street corner. These aggregation switches have many fiber ports and each port directly connects to an Optical Network Termination (ONT), which is located inside or outside the customer’s residence or business premises.

Each option has its own strengths and weaknesses:

Positives (PON):

A PON infrastructure is much less expensive to implement and maintain than PON.
The fiber splitters at the centre of a PON infrastructure don’t require any power supply.
Faster to deploy than a more complex PON infrastructure.
Negatives (PON):

PON infrastructures offer a limited level of bandwidth as it is shared between multiple subscribers.
Bandwidth is asymmetric, with much greater download capacity compared to upload.
Once implemented a EPON network is more difficult to update, particularly if bandwidth requirements change.
As optical splitters have both bandwidth limitations (particularly upstream). ]]> https://ameblo.jp/lidadaidaihuacapsule/entry-12031338770.html Tue, 26 May 2015 17:11:51 +0900
GPON

While GPON has been adopted as a technology of choice in high-speed access networks for inexpensive residential service delivery, more recently, it has begun to spread into business access. With the ability to deliver up to 10Gbps per GPON OLT port, it can also be a cost-effective technology for delivering higher bandwidth to cell towers.
GPON

Figure 1: GPON Network

Whether the GPON splitters are collocated with the OLT or distributed in the field, it is likely that a multiple of splitter modules would be needed to handle each serving area. To aid with this, the SplitLight HD can provide up to 16 GPON splitters in a single, 1RU chassis, while traditional solutions can only provide a single GPON splitter in the same footprint. In addition, legacy LGX solutions would require at least 4RU to deliver the same density.

WDM-PON

Building on the advantages of GPON, shared infrastructure and a single OLT transponder, WDM-PON provides the added advantage of delivering a dedicated wavelength to each GPON ONT. WDM-PON does not use a splitter. Instead, an Arrayed Waveguide Grating (AWG) is used to multiplex and de-multiplex wavelengths between the feeder fibers and distribution fibers. The result is dedicated bandwidth and a more secure network for each subscriber, or in this case, cell tower. Another advantage of WDM-PON is the ability to add/drop wavelengths at intermediate cell towers that lie between mobile switching centers.
WDM-PON

Figure 2: WDM-PON Network
As with GPON splitters, it is likely that multiple AWGs would be required at both ends of the WDM-PON network. The SplitLight HD can also house up to 12 AWGs in a single, 1RU chassis. In addition, the SplitLight HD has the flexibility to also house passive OADMs for the intermediate add/drops. ]]> https://ameblo.jp/lidadaidaihuacapsule/entry-12029723033.html Fri, 22 May 2015 16:28:56 +0900
A PON consists of an optical line terminal (OLT) at the service provider’s central office and a number of optical network units (ONUs) near end users. In OLT/ONU between the optical distribution network includes optical fiber and passive optical splitter or Fiber Optic Coupler.

OLT
An OLT, generally an Ethernet switch, router, or multimedia conversion platform, is located at the Central Office (CO) as a core device of the whole EPON system to provide core data and video-to-telephone network interfaces for EPON and the service provider.

ONU
ONUs are used to connect the customer premise equipment, such as PCs, set-top boxes (STBs), and switches. Generally placed at customer’s home, corridors, or roadsides, ONUs are mainly responsible for forwarding uplink data sent by customer premise equipment (from ONU to OLT) and selectively receiving downlink broadcasts forwarded by OLTs (from OLT to ONU).

ONT
An ONT consists of optical fibers, one or more passive optical splitters (POSs), and other passive optical components. ONTs provide optical signal transmission paths between OLTs and ONUs. A POS can couple uplink data into a single piece of fiber and distribute downlink data to respective ONTs.

There are two passive optical network technologies: Ethernet PON (EPON) and gigabit PON (GPON). EPON and GPON are applied in different situations, and each offers its own advantages in subscriber access networks. EPON focuses on FTTH applications while GPON focuses on full service support, including both new services and existing traditional services such as ATM and TDM.

EPON is a Passive Optical Network which carries Ethernet frames encapsulated in 802.3 standards. It is a combination of the Ethernet technology and the PON technology in compliance with the IEEE 802.3ah standards issued in 5-2015. A typical EPON system consists of three components: EPON OLT, EPON ONU and GPON ONT，It has many advantages, such as lower operation and maintenance costs, long distances and higher bandwidths.

GPON utilizes point-to-multipoint topology. GPON standard differs from other PON standards in that it achieves higher bandwidth and higher efficiency using larger, variable-length packets. And GPON is generally considered the strongest candidate for widespread deployments. GPON has a downstream capacity of 2.488 Gb/s and an upstream capacity of 1.244 Gbp/s that is shared among users.

There are also many differences between EPON and GPON. EPON, based on Ethernet technology, is compliant with the IEEE 802.3ah Ethernet in the First Mile standard that is now merged into the IEEE Standard 802.5-2015. It is a solution for the “first mile” optical access network. GPON, on the other hand, is an important approach to enable full service access EPON network. Its requirements were set force by the Full Service Access Network (FASN) group, which was later adopted by ITU-T as the G.984.x standards–an addition to ITU-T recommendation, G.983, which details broadband PON (BPON).

Both EPON and GPON are accepted as international standards. They cover the same network topology methods and FTTx applications, incorporate the same WDM technology, delivering the same wavelength both upstream and downstream together with a third party wavelength. PON technology provides triple-play, Internet Protocol TV (IPTV) and cable TV (CATV) video services. ]]> https://ameblo.jp/lidadaidaihuacapsule/entry-12029318190.html Thu, 21 May 2015 16:45:39 +0900
Under the broadband Fiber Optic Network in the trend, PON technology has become the world's attention to various telecom operators hot technology is one of the operators to implement "broadband speed", "Light of Copper" engineering technology base. Wheter EPON, or GPON, which provides only for the uplink and downlink bandwidth of

1. Defines six 10G EPON optical power budget, in view of the asymmetric mode PRX10, PRX20 and PRX30 as well as for symmetric mode PR10, PR20 and PR30, these six kinds of optical power budget model is basically to meet the construction needs of the service provider network;

2. 10G EPON technology in achieving the 1G EPON conventional multi-point control protocol layer (MPCP) based on the forward compatibility, also extended the original message type, for reporting optical terminal equipment (EPON OLT), EPON ONU Fiber Transceiver switch time to meet the 10G EPON network requirements;

3. 10G EPON uses (255, 223) Forward Error Correction (FEC) encoding method, the encoded with FEC coding for the same strain of 1G EPON, but its strong support 10G EPON coding gain can lower the sensitivity of the optical receiver;

4. 10G EPON uplink and downlink wavelength for the re-planning, downlink using 1268-1280nm wavelength, then reuse the original uplink of 1G EPON 1575-1580 nm wavelength, the wavelength in order to avoid conflicts, 10G EPON uplink only use time division multiple access (TDMA) manner.

Has been released G.987.1 standard that defines 10G GPON system's overall technical requirements and system architecture, clearly put forward the 10G GPON system to ensure good QoS, based on the traditional telecom services to fully support all emerging businesses and the same time, also provides dynamic Bandwidth Allocation (DBA) algorithm, energy saving, authentication and encryption related content to inherit the original 1G GPON suppliers; The G.987.2 is the focus of standardized 10G GPON physical layer parameters, including downlink rate, ODN power budget, splitting ratio, up and down the line wavelength range and line coding, etc., although down the line of 10G EPON same wavelength range and 10G EPON, GPON but due to the wavelength with 1G is not conflict, therefore, 10G GPON uplink and downlink are used wavelength division multiple access (WDMA) manner.

A complete industrial chain, including chip PON, optical modules and equipment three links. If to analysis PON industry chain, it need to start from the three links, analysis of every link current development status and future development trend.

Overall, 10G EPON and 10G GPON is currently not reach the requirements of large-scale commercial applications, although some equipment manufacturers have recently introduced a 10G EPON or 10G GPON products, and with operators, the creation of some experimental inning, but still in the laboratory testing phase, is still some distance away from the large-scale commercial.
10G PON technology to meet future access networks, "large-capacity, fewer offices," the direction of development, while improving access speed, supports larger branching ratio, covering more users. Therefore, 10G PON technology will become the future telecom operators to achieve "broadband speed", "Light of Copper" and other broadband network construction hot technology for sustainable development. ]]> https://ameblo.jp/lidadaidaihuacapsule/entry-12028909670.html Wed, 20 May 2015 15:57:36 +0900
As consumers world over have been demanding more and more bandwidth hungry applications at the network, networks of the future will be digital and intelligent and will offer high transmission capacity and flexible bandwidth. In addition to being easily accessible while offering services that are personalized and tailored to individual need. To support it, FTTx technology, as a effectively one, is widely used in our life nowadays.

Passive Optical Network (PON), a new technology for networking infrastructure, is widely deployed in today's FTTx network in new installations and is generally considered suitable for consumer broadband services.
As an indispensable component of Passive Optical Network (PON) systems, PON splitter is used to distribute or combine optical signals, installing in an outside plant enclosure and giving carriers the ability to split optical signals to multiple homes or businesses.



1xN Splitter working in the HFFx

According to the Fiber Optic Splitter principle, there are two kinds of PON splitter: EPON OLT/EPON ONU/GPON ONT/GPON OLT. Between them, PLC splitter is valued by its wider operating wavelength because PLC splitter can work on 1260-1650nm wavelength, while FBT can usually work on three different operating wavelengths. What's more, depending on its split configuration, there are types of PLC splitter designed in 1xN and 2xN, such as 1×4, 1×8, 1×16, 1×32, etc. or smaller, like 1×2, 1×4, etc. for the FBT splitter.

In addition, in order to meet clients’ different requirements, different package are produced by the manufacturers depending on subscriber conditions or cable length, and even the connectors.

Fiberstore offers a integrated product line of these different types of PON splitters. Fiberstore's fiber optic splitters can be terminated with different kinds of connectors. They are protected from exposure and damage by their packaging. Surrounded by superior cable management, technicians need less time to route fiber in the cabinet, saving operating costs. Available in configurations from 1x2 up to 1x64, the modules can be ordered in adapter port or pigtailed versions. We are specialized in supportting a perfect work for your FTTx solutions.

Types of Fiberstore's PON splitters:

Bare fiber splitter-the PLC splitter without connectors
Blockless fiber splitter-PLC Splitter with LC/SC/FC/ST connectors - direct 900μm output
Fanout Splitters-PLC Splitter with LC/SC/FC/ST connectors and Fan-out Kit
ABS & LGX Splitters-PLC Splitter module with 0.9/2/3mm cable input and output
Rack Chassis Splitter- PLC Splitter mounted in patch panel
FBT Couplers Splitters
Want a highly splitter product? Want your network working perfectly and stably? Fiberstore is your best alternative! We offers all good quality products with reasonable price. To contact Fiberstore, please log in our website! ]]> https://ameblo.jp/lidadaidaihuacapsule/entry-12028534052.html Tue, 19 May 2015 17:20:14 +0900
DWDM can be implemented with an MSPP in two ways. Most often when you think about DWDM systems. However, the multiplexing of multiple light source is always a "passive" activity. Wavelength conversion and amplification is always the "active" DWDM activity.

MSPP chassis with integrated DWDM optics in which the optics cards (in this case, OC-48s) use one of the ITU wavelengths and interfaces to an external filter. This filter multiplexes the wavelengths from various optics cards within multiple chasses and transports them over the fiber, where they are demultiplexed on the MSPP because the filter is a separate device.

This inefficient use of the rack and shelf space has led to the development of active DWDM from the MSPP. With active DWDM, the transponding of the ITU wavelength to a standard 1550-nm wavelength is performed by converting the MSPP shelf into various components required in a DWDM system. This conversion has greatly increased the density of wavelengths within a given footprint. For example the kind of passive DWDM, only 16 wavelengths could be configured within a bay, 4 per chassis. With today's multiport, multiport optical cards, this density can be doubled to 8 wavelengths per shelf and 32 per rack.

With the integrated active DWDM solution, one MSPP chassis can be converted into a 32-channel multiplexer/demultiplexer using reconfigurable optical add/drop multiplexer (ROADM) technology. Other chassis can be converted into a multiplexer (OADM), which can receive and distribute multiple wavelengths per shelf. The implication of this is that up to 32 wavelengths can be terminated within a bay or rack, a factor of eight times the density of even early MSPPs using a passive external filter. The traffic from within each wavelength dropped into an MSPP shelf from the ROADM hub shelf can be groomed or extracted from the wavelengths carrying it, as needed, and dropped out of the OADM shelves. ROADM is an option that can be deployed in place of fixed-wavelength OADMs. Cisco Systems ROADM technology, for example, consists of two modules: 32-channel reconfigurable multiplexer (two-slot module), 32-channel reconfigurable demultiplexer (one-slot module). Use of software-provisionable, small form-factor pluggable（SFP）client connectors, and wavelength tunability for reduced card inventory requirements. Multilever service monitoring: SONET/SDH, G.709 digital wrapper, and optical service channel for unparalleled service reliability.

MSPP chassis

With so many advantages, one of the disadvantages is that parading shift is required to move the market toward MSPP-based DWDM. This slow migration is keeping vendors at bay in terms of development as they try to balance investment in the future with today's revenue. The widespread introduction of this technology, however, DWDM price also should be considered. The price of DWDM transceivers is typically four to five times more expensive than that of their CWDM counterparts. The higher DWDM transceiver costs are attributed to a number of factors related to the lasers.

Several ways exist for protecting an MSPP-based DWDM system in the event of a fiber cut or signal degradation. Such protection options include client protection, Y-cable protection, and wavelength splitting.

Reliability for these options varies, depending on the client network architectures and service-level agreements (SLA) provided to the client. Thus, there is no "one size fits all" approach to protection.


Related websites: http://www.fiberstore.com ]]> https://ameblo.jp/lidadaidaihuacapsule/entry-12026535912.html Thu, 14 May 2015 15:37:41 +0900
Radio and television networks in recent DWDM multiplexer business growth is faster in a given area, is the region development education network access project, due to the previous optical fiber network resources is mainly used in cable television network, optical fiber resources is not so rich, many county to the town had no residual fiber resources, to increase the data business, now want to be in the original on the fiber optic cable TV network transmission using again, plus infomation data signals, or want to lay out the other cable the main work, need to solve as many towns in this area belongs to mountainous area, cable laying is not very convenient, considering various factors such as resources, cost, on the radio and television networks company specialized in optical network access technology co., LTD. Shenzhen Fiberstore CWDM system to conduct a comprehensive performance analysis and product testing.And start in areas such as education network access to A project on each node USES many Fiberstore CWDM system equipment.

The radio and television networks of CWDM project at present is mainly used to implement the education network (10/100 MBPS Ethernet) hybrid transmission signals and the cable television network, the current direction of projects with a total of eight different contact, sharing the 3 sets of Fiberstore the CWDM system equipment.
In this scenario, A computer room - B node transfer 2 10/100 MBPS data signals and A cable TV signal, which is based on WDM CWDM access, two 10/100 MBPS signals after Fiberstore C5002S through Fiberstore HA - WDM multiplexer, and cable television signals and reuse all the way to A single fiber, transfer to the access point B region, middle transmission distance of 50 km, implements and Ethernet cable TV signal on the single fiber CWDM module of hybrid transmission.
A room - C nodes use sea pegatron C5002S system combined with high speed and CWDM terminal transceiver effectively cooperate with access, realize two-way 10/100 MBPS of hybrid transmission over A single optical fiber.
A-D-E by Fiberstore C5004S system combining various nodes of high speed and the corresponding CWDM transceiver implementation 4 10/100 MBPS signals on A single optical fiber access project, through the high speed connection between each contact, through the terminal CWDM wavelengths optical transceiver connected to A contact switch, after the C5004S system in the computer room 4 different signals, respectively in different wavelengths transmitted to each destination, after D primary school, through high speed download local signal, the remaining 3 to continue down the road signal to the corresponding destination.

Save fiber resources CWDM (Coarse where division multiplexing) Coarse wavelength division multiplexing system, which USES optical multiplexer in the different optical fiber transmission wavelength multiplexing in a single fiber transmission;On the receiving end of A link, using wavelength multiplexer and then revert to the original wavelength, using optical fiber all the way, on the whole link is solved effectively under the condition of the optical fiber resources extremely nervous network access, this scenario, A, D, E, between transmission on A single fiber and four 10/100 MBPS (also can be 1000 MBPS) signal, A room - B node is in the original cable TV signal transmission on A single fiber loading 2 10/100 MBPS signals, save A lot of fiber resources. 2.More business and high bandwidth CWDM is a according to the practical application to the transfer rate of adaptation based transmission platform, support a variety of business transfer.At each wavelength, the support of the business including 10 m / 100 m / 1000 m Ethernet, 155 m / 622 m / 2.5 G of SDH, 155 m / 622 m ATM business, as well as the Fiber Channel business, and so on.The whole system capacity to play a few Gbps data signal.Fully meet user bandwidth requirements in quite some time.This scenario USES is 10/100 MBPS business with cable TV signal for hybrid transmission.

CWDM price than the price of L band DWDM transceiver is relatively low, due to the power of CWDM is small, small volume, easy to use, thus supporting facilities, personnel training and the late maintenance cost is low.Compared with optical cable project: using CWDM device is opened rapidly, low cost, convenient network upgrades, late and increasing need of signal directly, or replace the higher rate of product, don't need to change the fiber link, convenient network upgrades, reduces the network upgrade costs.The above scenario A-D-E, if change into 1000 MBPS data signals, the capacity of the network directly to upgrade to the 4 GBPS. CWDM in hybrid access network in the use of the business. ]]> https://ameblo.jp/lidadaidaihuacapsule/entry-12026151565.html Wed, 13 May 2015 15:51:30 +0900 16 channel DWDM MUX doing so justifies the cost. If a company has already invested in laying down fiber, that initial investment can be protected by using such a DWDM system. Using this system multiplies the capacity of the existing fiber by up to 10 or more times. This type of system is necessary for internet providers because of the rapid expansion of internet subscribers. If DWDM systems did not exist, the only way for these companies to meet the demand of internet users would be to lay new fiber. It is much more cost-effective for them to implement DWDM systems and thus alleviate the bandwidth concern. .

Research is advancing the technology to the point where 800 wavelengths on a single fiber could be feasible. The amount of data that modern applications require continues to grow. Where bit rates of a few Gbps were once sufficient, modern consumer and corporate needs necessitate Tbps. This type of growth could not have been anticipated when the first WDM systems were introduced, but the tranponder based DWDM systems are capable of meeting modern demands.

In their first incarnations, terminal demultiplexers were passive systems. As the complexity of DWDM systems increased, the need for an active approach did, too. Terminal demultiplexers take the signal, which is composed of several wavelengths by this point, and breaks it down to its constituent signals. These signals are then sent through individual fibers to their destinations. The active terminal demultiplexers first go through an output transponder before they are transmitted, which can also go through an error correction procedure. These transponders can also be placed a longside the input transponders.

Intermediate line repeaters are placed between 80 and 100 km apart along the path of the fiber. If the optical signal has travelled more than 140 km before arriving at its destination, an DWDM passive MUX is placed. It serves to not only amplify the signal, but also as a diagnostic point. If locations further down the path of the fiber are having issues with the signal, these sites can be used to determine if the fiber has been damaged or otherwise impaired.

Within the DWDM system a transponder converts the DEMUX CWDM client optical signal from back to an electrical signal and performs the 3R functions. This electrical signal is then used to drive the WDM laser. Each transponder within the system converts its client's signal to a slightly different wavelength. The wavelengths from all of the transponders in the system are then optically multiplexed. In the receive direction of the DWDM system, the reverse process takes place. Individual wavelengths are filtered from the multiplexed fiber and fed to individual transponders, which convert the signal to electrical and drive a standard interface to the client.

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