Perfect Couple: Fiber Splice Tray and Fiber Enclosure

In the cabinet, we may find many devices and gadgets, such as fiber patch panel, fiber splice tray, fiber enclosure, adapter panel and zip ties which are all little but critical components for cable management. Fiber patch panel, the one we have cued for a lot of times, will give way to fiber splice tray and fiber enclosure, the two subjects that we will introduce today.

Fiber Splice Tray Unveil

As we all know, it is usually unavoidable to match splice fiber optic cables with fiber pigtails in data center, which not only demands lower space requirement but also allows a better network performance compared with other fiber optic termination methods.

Fiber splice tray, very popular in data center and server room, is a plate to store the fiber cables and splices and prevent them from becoming damaged or being misplaced. Splice trays are necessary for holding and protecting individual fusion splices or mechanical splices. One of the important factors of fiber splice tray is the fiber count that it can hold. Most fiber splice tray can hold up to 24 fiber splices. 12-fiber splice trays are the most commonly used fiber splice tray in fiber optic network.

A Closer Look At Fiber Enclosure

It is a box that contains the devices to connect various fiber optic cables. Fiber enclosures can be classified into two configurations, namely rack mount fiber enclosure and wall mount fiber enclosure. And the rack mount fiber enclosure can be further categorized by its height and the design. We have 1U, 2U and 4U choices. The rack mount enclosures come in two flavors. One is the slide-out variety , and the other incorporates a removable lid which requires the user to remove the whole enclosure from the rack to gain internal access.

How The Two Coordinate?

Owning solely a fiber splice tray is far more enough. It should be equipped with a device to provide a safe and easy-to-manage environment for fiber splices. Apart from fiber optic splice closure, fiber distribution box and fiber optic enclosure, we can adopt the fiber enclosure displayed today. Fiber splice tray can be installed in fiber enclosure.

Here takes the example of fiber splice tray used in FHD fiber enclosure of FS.COM as shown in the following picture. It is a 96-fiber enclosure which has four 24-fiber adapter on the front panel. This 1U fiber enclosure can hold up four 24-fiber splice tray to provide the space for 96 fiber optic splices.

fiber splice tray and enclosure

Conclusion

As optical fibers are sensitive to pulling, bending and crushing forces, fiber splice tray and fiber enclosure serve as double protections which are used to provide a safe routing and easy-to-manage environment for the fragile optical fiber splices. Attention! Bare fibers without protection tubes should never be exposed outside of a splice tray. It’s our pleasure to provide you with the best solutions.

What’s the Difference: Transceiver vs Transmitter

Today, let’s learn and compare two terms in optic communication: transceiver vs transmitter(originated in the early 1920s. Looking up in the dictionary, we can distinguish that transmitter is a device that transmits something(in all senses), and transceiver is a combined transmitter and receiver.

Transmitter

A transmitter can either be a separate piece of electronic equipment or an integrated circuit (IC) within another electronic device. A transmitter generates a radio frequency current applied to the antenna, which in turn radiates radio waves for communication, radar and navigational purposes. The information that is provided to the transmitter is in the form of an electronic signal. This includes audio from a microphone, video from a TV camera, or a digital signal for wireless networking devices. The electronics for a transmitter are simple. They convert an incoming pulse (voltage) into a precise current pulse to drive the source. Different transmitter has different functions. Take the optical transmitter as an example, it consists of the following components: optical source, electrical pulse generator and optical modulator. And the role of it is to convert the electrical signal into optical form, and launch the resulting optical signal into the optical fiber.

Transceiver

A transceiver is a device made up of both a receiver and transmitter (the name “transceiver” is actually short for transmitter-receiver) and these two gadgets are in a single module. When no circuitry is common between transmit and receive functions, the device is a transmitter-receiver.

Transceivers can be found in radio technology, telephony as well as Ethernet in which transceivers are called Medium Attachment Units (MAUs) in IEEE 802.3 documents and were widely used in 10BASE2 and 10BASE5 Ethernet networks. Fiber-optic gigabit, 10 Gigabit Ethernet, 40 Gigabit Ethernet, and 100 Gigabit Ethernet utilize transceivers known as GBIC, SFP, SFP+, QSFP, XFP, XAUI, CXP, and CFP, among which Cisco SFP is the most popular one. In addition, 1000BASE-T SFP, 10GBASE-T SFP+ and 1000BASE-T copper SFP we mentioned before are all transceivers.

third-party-transceiver

Transceiver vs Transmitter

From the above information, we can know that the transmitter can only be used to transmit signals, while the transceiver can both transmit and receive signals. However, many view transceivers as a compromise in terms of performance, functionality, portability and flexibility and if they had any practical value it would be in mobile and portable applications. Transceivers sacrificed some features and performance to gain the smaller size/weight and cost.

As for the portability, a transceiver just needs the space of one module, but functions as two different modules. It is easy to be taken on the go. Separate transmitter is not as convenient in some circumstances as it is probably heavier, and takes up more room. But they are advantageous because each could benefit from its own design, without compromising in areas such as I-F frequency choice, conversion frequencies, and audio stages and they are easier to build and work on.

As far as the price is concerned, in most cases, a separate transmitter consumes more power. And the price of a single transceiver is much lower than that of a transmitter plus a receiver.Using a common frequency generation/tuning scheme, power supply and other components, it costs less to manufacture a transceiver than a separate transmitter and receiver.As to how to choose from them, the answer depends on your application.

Conclusion

You may find many transmitters in you life, like the TV remote control. Although transceiver is not commonly noticed around you, it is actually commonly applied to many places. We can say that it is invisible but versatile. I sincerely hope that this article will help you understand the difference: transceiver vs transmitter, only then, can you use them in the right way.

Are You Ready For 400G Ethernet?

The rapid development in telecom industry is driving massive demand for higher bandwidth and faster data rate, from 10G to 40G and 100G, will this keep going on? The answer is definitely “Yes”. Some time ago, migration from 10G to 40G or 25G to 100G has been a hot spot among data center managers. While recently, 400G solutions and 400G components are coming. Are you ready for 400G? This article will share some information about 400G Ethernet.

Overview of 400G

In the past couple of years, modules with four 25/28G lanes or wavelengths are the solutions for 100G Ethernet. However, they were expensive at the beginning. Until 2016, the optical components industry has responded to the demands with 100G solutions that already cost less per gigabit than equivalent 10G and 40G solutions, and new developments to further drive down cost and increase bandwidths. The next generation is 400G Ethernet. The IEEE has agreed on PSM4 with four parallel fibers for the 500 meters 400GBASE-DR4 specification that is part of the IEEE802.3bs standard being developed for approval by the end of 2017. The industry is already developing optical components for 400G Ethernet solutions. The following figure shows telecom and datacom adoption timelines.

Telecom and datacom adoption timelines

We can visually see that telecom/enterprise applications first adopted 100G technology in the form of CFP modules. Data centers generally did not adopt 100G interfaces until the technology matured and evolved towards denser, lower power interfaces, particularly in the form of QSFP28 modules. However, as the hyperscale data center market scales to keep pace with machine-to-machine communications needs, data center operators have become the first to demand transmission modules for data rates of 400G and beyond. Therefore, the 400G era is now upon us.

Modules for 400G

We know that the QSFP28 modules for 100G Ethernet and SFP28 modules for 25G Ethernet are now the dominant form factors. Though CFP, CFP2 and CFP4 modules remain important for some applications, they have been eclipsed by QSFP28 modules. To support higher bandwidth, what is the right module for 400G? The first CFP8 modules are already available. QSFP-DD is backward compatible with QSFP, and OSFP may deliver better performance, especially as networks move to 800G interfaces.

CFP8 module: CFP8 module is the newest form factor under development by members of the CFP multisource agreement (MSA). It is approximately the size of CFP2 module. As for bandwidth density, it respectively supports eight times and four times the bandwidth density of CFP and CFP2 module. The interface of CFP8 module has been generally specified to allow for 16 x 25 Gb/s and 8 x 50 Gb/s mode.

100G CFP to 400G CFP8

QSFP-DD module: QSFP-DD refers to Quad Small Form Factor Pluggable Double Density. It uses eight 25G lanes via NRZ modulation or eight 50G lanes via PAM4 modulation, which can support optical link of 200 Gbps or 400 Gbps aggregate. In addition, QSFP-DD module can enable up to 14.4 Tbps aggregate bandwidth in a single switch slot. As it is backwards compatible with QSFP modules, QSFP-DD provides flexibility for end users and system designers.

QSFP-DD vs QSFP

OSFP module: OSFP (Octal Small Form Factor Pluggable) with eight high speed electrical lanes is able to support 400G (8x50G). It is slightly wider and deeper than the QSFP but it still supports 36 OSFP ports per 1U front panel, enabling 14.4 Tbps per 1U. The OSFP is able to meet the projected thermal requirements for 800 Gbps optics when those systems and optics become available in the future.

OSFP module

Conclusion

Judging from the current trends, 400G will become the mainstream in the near future. But there are still some challenges for it to overcome, such as high capacity density, low power consumption, ever lower cost per bit, and reliable large-scale manufacturing capabilities. You never know what surprise the network will bring to you, let’s wait and see the 400G’s time.

Fiber Optic Connectivity Options for 40G Infrastructure

Dramatic growth in data center throughput has led to the increasing usage and demand for higher speed and more bandwidths. The speed of data center now is increasing to 40 Gbps and eventually to 100 Gbps. Thus, new optical technologies and cabling infrastructure are required. This article will introduce some commonly used fiber optic cabling connectivity options for 40G infrastructure.

Pluggable Optical Modules: 40G QSFP+ Transceivers

As is known to all, fiber optic transceiver is a device that both transmits and receives data. It is the key component in fiber optic transmission. The basic interface of 40G pluggable optical modules are 40GBASE-LR4 and 40GBASE-SR4 in QSFP+ form factor.

40GBASE-LR4 QSFP+: 40GBASE-LR4 transceiver supports with a link length up to 10 kilometers over 1310 nm single mode fiber with LC connector. It is most commonly deployed between data-center or IXP sites with single mode fiber.

40GBASE-SR4 QSFP+: 40GBASE-SR4 transceivers are used in data centers to interconnect two Ethernet switches with 8 fiber parallel multimode fiber OM3/OM4 cables. It can support the transmission distance up to 100 m with OM3 fiber and 150 m with OM4 fiber. The optical interface of 40GBASE-SR4 QSFP+ is MPO/MTP.

Extreme 10319

In addition, for single-mode fiber transmission, there are 40GBASE-LR4 Parallel Single Mode (PSM) transceivers which are used to provide support for up to four 10Gbps Ethernet connections on a QSFP+ port over single mode fiber at distances up to 10 km. For multimode fiber transmission, QSFP+ extended SR4 transceivers are developed which is designed with optimized VCSEL with better performance of RMS spectral width compared with QSFP+ SR4. QSFP+ extended SR4 transceivers can support transmission distance up to 300 m with OM3 fiber and 400 m with OM4.

Passive & Active Direct Attach Copper Cables

The QSFP+ passive or active direct attach copper cables are designed with twinax copper cable and terminated with QSFP+ connectors. The main difference between passive QSFP+ DAC and active QSFP+ DAC is that the passive one is without the active component. They provide short distance (same shelf) inexpensive connectivity at up to 40Gbps rates and operate 4 independent 10G channels using the QSFP connector footprint. Each of the four channels can operate at multi-rate speeds Gigabit to 10Gbps. For example, Juniper QFX-QSFP-DACBO-3M compatible QSFP+ to 4SFP+ copper direct attach cables are suitable for very short distances and offer a very cost-effective way to establish a 40-gigabit link between QSFP port and SFP+ port of Juniper switches within racks and across adjacent racks.

Active Optical Cable (AOC) Assemblies

Active Optical Cable (AOC) is used for short-range multi-lane data communication and interconnect applications. It uses electrical-to-optical conversion on the cable ends to improve speed and distance performance of the cable without sacrificing compatibility with standard electrical interfaces. AOC brings a more flexible cabling than direct attach copper cables with the advantages of lighter weigth, longer transmission distance and higher performance for anti-EMI. Now, 40G AOC assemblies are popular with users.

40G cabling

Fiberstore offers a comprehensive solution for 40G fiber optic cabling connectivity. Apart from the above-mentioned cabling connectivity options, there are also some typical cabling components you will require when building 40G cabling, such as MTP trunk cables, MTP cassettes, LC to MTP jumpers and so on.

The Application of TDM-PON And WDM-PON

1. Instruction
The bandwidth requirements of the telecommunication network users increased rapidly during the recent years. The emerging optical access network must provide the bandwidth demand for each user as well as support high data rate, broadband multiple services and flexible communications for various end-users. Being considered as a promising access network solution due to the high bandwidth provision and the low operation and maintenance cost, passive optical networks (PONs) represent one of the most attractive access network solutions. TDM and WDM techniques are employed in the PON for higher resource efficiency and capacity, which results in TDM-PON and WDM-PON respectively. TDM-PON provides much higher bandwidth for data application but it has limited availability to end-users. WDM PON can solve the problems encountered in TDM-PON by allocating a specified wavelength to each subscriber. This provides a separate, secure P2P, and high data-rate channel between each subscriber and the CO. This article is mainly written to give you a overview of the application of TDM-PON and WDM-PON as well as the joint application—TWDM PON.

2. Application of TDM-PON
TDM-PON types include ATM PON (APON), Broadband PON (BPON), Ethernet PON (EPON), Gigabit PON (GPON). Now EPON and GPON are extensively used in the telecommunication networks.

2.1 Application of EPON
Ethernet PON (EPON) is a PON-based network that carries data traffic encapsulated in Ethernet frames (defined in the IEEE 802.3 standard). A typical EPON system consists of three components: optical line terminal (OLT), optical network unit (ONU), and optical distribution network (ODN). Utilizing PON topological structure to achieve the access of Ethernet, EPON is equipped with the dual advantages of PON and Ethernet including low cost, high bandwidth, strong scalability, excellent compatibility with Ethernet to facilitate network management, etc. Based on where ONUs are deployed, EPON application mode can be fiber to the curb (FTTC), fiber to the building (FTTB), and fiber to the home (FTTH), as shown in Figure 1.

Application of EPON in FTTB, FTTC and FTTH

Figure 1: The application of EPON in FTTB, FTTC and FTTH

In a FTTC system, ONUs are deployed at roadside or beside the junction boxes of telegraph poles. Usually, twisted-pair copper wires are used to connect the ONUs to each user, and coaxial cables are used to transmit broadband graphic services. Currently, the FTTC technology is the most practical and economical Optical Access Network (OAN) solution for providing narrow-band services below 2 Mbps. For services integrating narrowband and broadband services, however, FTTC is not the ideal solution.

In a FTTB system, ONUs are deployed within buildings, with the optical fibers led into user homes through ADSL lines, cables, or LANs. Compared with FTTC, FTTB has a higher usage of optical fiber and therefore is more suitable for user communities that need narrowband/broadband integrated services.

In a FTTH system, ONUs are deployed in user offices or homes to implement a fully transparent optical network, with the ONUs independent of the transmission mode, bandwidth, wavelength, and transmission technology. Therefore, FTTH is ideal for the long term development of optical access networks.

2.2 Application of GPON
Gigabit PON (GPON) is the far-most advanced PON solution used by European and US providers. It is somehow based on the former ATM access networks (APON, BPON), but GPON’s data encapsulation (GEM) is more generic, and accepts different network protocols, such as ATM, Ethernet and IP. A traditional GPON system is made up of three parts: optical line terminal (OLT), optical network terminal (ONT) or ONU, and optical distribution network (ODU) composed of SM fiber and splitter. GPON possess the advantages of high bandwidth, high efficiency, large coverage, abundant user interfaces, etc. In the access network, GPON can be used to fiber to the building (FTTB), fiber to the curb (FTTC), and fiber to the home (FTTH), as shown in Figure 2.

GPON-application

Figure 2: The application of GPON in FTTB, FTTC and FTTH

In a FTTB system, ONTs are deployed within buildings. GPON can be used to serve for the users of multi-dwelling units (MDU) as well as business users. When serving for MDU users, the services supported by GPON contains asymmetric broadband services (digital broadcast, VOD, IP TV) and symmetric broadband services (content broadcast, e-mail, remote diagnose). When serving for business users, the services supported by GPON are symmetric services (group software, content broadcast, e-mail). Facing diverse services, GPON must flexibly provide private line service at different rate.

In a FTTC system, ONTs are deployed at roadside or beside the junction boxes of telegraph poles. The services supported by GPON consists of asymmetric services ( digital broadcast, VOD, IP TV, files downloading, online games) and symmetric services (content broadcast, e-mail, files interaction, remote education). In addition, GPON supported the expansion of the dedicated line POTS and ISDN.

In a FTTH system, ONTs are deployed in user offices or homes. GPON supports the asymmetric services and symmetric services. The asymmetric services include data broadcast, VOD, IP TV, files downloading, etc. The symmetric services include content broadcast, e-mail, files interaction, remote education, remote diagnose, online games, etc. What’s more, GPON supported the expansion of the dedicated line POTS and ISDN.

3. Application of WDM-PON
As the new-generation access network, WDM-PON makes it possible to transmit multiple wavelengths instead of one wavelength in the PON over the same fiber, thus greatly meet the bandwidth requirements of users. In addition to its efficient use of wavelengths, the WDM-PON also has advantages in its use of optical-transmission power. The network management is much simpler than a TDM-PON, and all future services can be delivered over a single network platform.

WDM-PON can be directly used to achieve FTTC, FTTB and FTTH (see Figure 3) and provide services for business subscribers, the single-family subscribers, the multi-family subscribers and other types subscribers at the same time. WDM-PON offer abundant bandwidth to better meet the bandwidth requirements of the back transmission of 3G and LTE base station, thus becoming the optimal technology for the back transmission of mobile station. WDM-PON also can be used to support reach extension and the transition of existing EPON networks to improve the scalability as well as protect the existing network investment. What’s more WDM-PON can also be adpoted to build the hybrid WDM-TDM PON which combines the dual advantages of TDM-PON and WDM-PON with TDM-PON to be better applied in the optical communication network and provide better services for subscribers. WDM-PON is very suitable for the application environment of telecommunication.

WDM-PON application

Figure 3: The application of WDM-PON in FTTC, FTTB and FTTH

4.Joint Application of TDM-PON and WDM-PON
The combination of TDM and WDM in a PON network could be the most cost effective way of introducing TDM/WDM PON into the access network, which brings TWDM-PON into being. Figure 4 shows the architecture of TWDM-PON . Four XG-PONs are stacked by using four pairs of wavelengths {(λ1, λ5), (λ2, λ6), (λ3, λ7), (λ4, λ8)}. For simple network deployment and inventory management purposes, the ONUs use colorless tunable transmitters and receivers. The transmitter is tunable to any of the upstream wavelengths, while the receiver can tune to any of the downstream ones. To achieve a power budget higher than that of XG-PON1, optical amplifiers are employed at the OLT side to boost the downstream signals as well as to pre-amplify the upstream signals. ODN remains passive since both the optical amplifier and WDM Mux/DeMux are placed at the OLT side. Taking the advantages of TDM-PON and WDM-PON and overcoming their shortcomings, TWDM-OPN can provide higher rates and bandwidth to better serve users.

TWDM-PON architecture

Figure 4: The network architecture of TWDM-PON

TWDM-PONcould be applied in the following ways. The first one to consider is used for pay-as-you-grow provisioning. The TWDM-PON system could be deployed by starting with a single wavelength pair. It could be upgraded by adding new wavelength pairs to increase the system capacity. In this way, the operators can address the bandwidth growth demand by investing what is needed and expanding the future demand. Another application of TWDM-PON is for local loop unbundling (LLU). A TWDM-PON with multiple OLT arrangement is shown in Figure 5 for LLU. Each operator would have their own OLT, each of which would contain some set of wavelength channels. A wavelength-selective device would be used to multiplex the OLT ports onto a single fiber. The wavelength-selective device could be as simple as a filter-based demultiplexer, or it could be an arrayed waveguide router type of device. This scheme unbundles the shared infrastructure for multiple operators. It also offers the possibility of every operator’s OLT being the same (containing all the wavelengths), and a single operator could add OLT resources as they want. What’s more, TWDM-PON can applied in the above-mentioned ways of TDM-PON and WDM-PON being applied.

TWDM-PON application for LLU

Figure 5: The application of TWDM-PON for LLU

5.Conclusion
TDM-PON and WDM-PON, as the popular optical access network , are extensively used in the communication networks. WDM-PON solves the problems of limited bandwidth to each subscriber, high transmission power and poor network security exsiting in TDM-PON, becoming the new-generation access network. However, the cost WDM-PON components are relatively high, which lessen its population. Nowadays the high-speed broadband penetration and ongoing growth of the Internet traffic among customers have been placing a huge bandwidth demand on the telecommunication network. TWDM-PON, combining the advantages of TDM-PON and WDM-PON, comes into being to become the far-most advanced PON. Being able to provide higher bandwidth, higher rates in downstream and upstream and competitive cost, TWDM-PON will plays a key role in the optical communication networks.