MPO cable and MTP cable are offered for various applications for all networking and device needs like 100 Gig modules. They use a high-density multi-fiber connector (MPO connector and MTP connector) system built around precision molded MT ferrule. So what are MPO and MTP connectors?

What is an MT ferrule?
MT stands for Mechanical Transfer. The MT Ferrule is a multi-fiber ferrule in which fiber alignment is dependent on the eccentricity and pitch of the fiber and alignment pin holes. The alignment is dictated by the alignment pins during mating.

The critical elements for fiber alignment are:

1. The ability to hold extreme tolerances for precision during the molding process

2. The shape, tolerances and material composition of the alignment pins

What is a MPO connector?

MPO is the industry acronym for “Multi-fiber Push On.” The MPO-style connectors are most commonly defined by two different documents:

1. IEC-61754-7 is the commonly sited standard for MPO connectors internationally

2. EIA/TIA-604-5, also known as FOCIS 5, is the most common standard sited for in the US

What is a MTP connector?

The MTP connector is a high performance MPO connector with multiple engineered product enhancements to improve optical and mechanical performance when compared to generic MPO connectors. It is in complete compliance with all MPO connector standards including the EIA/TIA-604-5 FOCIS 5 and the IEC-61754-7. It is inter-matable with all generic MPO-style connectors that are compliant to these industry standards. Generic MPO connectors are limited in performance and are not able to offer the high performance levels of the US Conec MTP connector.

Is the MTP connector an MPO connector?

Yes. The MTP connector is a high performance MPO connector engineered for better mechanical and optical performance.

What makes the MTP connector superior to generic MPO connectors?

The MTP connector has features and benefits that are not available on generic MPO connectors. Some of the key distinctions include:

1. The MTP connector housing is removable. This feature allows the customer to:

A. Re-work and re-polish the MT ferrule

B. Change the gender after assembly or even in the field

C. Scan the ferrule interferometrically after assembly

2. The MTP connector offers ferrule float to improve mechanical performance. This allows two mated ferruled to maintain physical contact while under an applied load.

3. The MTP connector uses tightly held tolerance stainless steel guide pin tips with an elliptical shape. The elliptical shaped guide pin tips improves guidance and reduces guide hole wear.

4. The MTP connector has a metal pin clamp with features for centering the push spring. This feature:

A. Eliminates lost pins

B. Centers spring force

C. Eliminates fiber damage from spring

5. The MTP connector spring design maximizes ribbon clearance for twelve fiber and multifiber ribbon applications to prevent fiber damage.

6. The MTP connector is offered with four standard variations of strain relief boots to meet a wide array of applications.

A. Round, Loose Fiber Cable Constructions

B. Oval Jacketed Cable

C. Bare Ribbon Fiber

D. Short boot which reduces the footprint by 45%. Ideal for use in space limited applications.

FiberStore news, the Chinese traditional fiber optic connector manufacturers not fared well in 2013, according to statistics, in the first quarter shipments of fiber optic connectors for FTTH "cold junction" decreased nearly 80% compared to 2012, which is regarded as technical magic for rapid deployment of FTTH by operators, gradually fell out of favor.
 
In the FTTH project, inevitably need to connect 5-7 fiber breakpoint. Before the advent of FTTH, fiber is mainly used for the backbone network, the breakpoints are using fusion splicer to connect, but because of its fusion splicer bulky, expensive, difficult to master the technology, these characteristics make it does not apply to FTTH project fast, low cost, convenience requirements.
 
Therefore, a few years ago, the industry developed fast connector, simple, convenient and low cost of FTTH splice junction, called the cold welding technology. United States, Japan, South Korea, which are the earliest development scale of FFTH, all have used the cold welding technology, verify the maturity of this technology.
 
"Hot melt" Return
 
In 2011, China Telecom launched the "city network" strategy, start the FTTH large-scale construction of China, and follow the international operators used cold welding technology. For a time, Chinese fast connector market raised quickly.
 
In the second half of 2011, cold welding technology began a large-scale unsuitable. The cold welding industrial chain which lacked details exposed its shortcomings: Although the same shape, but the heart technology of slot technology and matching fluid were unable to mark the international technology, below standard connectors entered into the network, caused massive FTTH quality problems.
 
In 2012, the three big operators reflected on this, Wei Leping, China Telecom Science and Technology Committee, noted: "FTTH network with serious quality problems, the network Splice, splitters and other products need to strengthen quality inspection." But the problem was not changed with the operator's attention. At present, in addition to Shanghai and Jiangsu, FTTH from other provinces still have serious quality problems.
 
However, it also provides an opportunity for some vendors. Fusion Splicers with "Miniaturization, long battery life, low cost, easy to operate" characters became hot topics in research and development.

1.If the indicating lamp of fiber optical transceiver or optical module and twisted pair cable port is light?

a. If the transceiver optical port (FX) indicator is not light, make sure whether the fiber link is a cross-linked fiber link. A fiber optic patch cord is connected in parallel; the other end is connected to a cross pattern.

b. If A transceiver optical port (FX) indicator lights but B transceiver optical port (FX) indicator is not light, then the fault is the A transceiver side. One possibility is: A transceiver (TX) optical transmitter port is bad and B transceiver optical port (RX) fails to receive optical signal. Another possibility is: There is a problem in fiber link of A transceiver (TX) optical transmitter port. (fiber optical cable or fiber optic patch cord may break.)

c. Twisted pair (TP) patch cable indicator is not light, make sure whether the twisted pair wiring is wrong or the twisted pair connection is incorrect? Please use on-off tester to test. (mind twisted pair cable indicator of some transceivers will light until the fiber link is connected.)

d. some transceivers have two RJ45 ports: (To HUB) indicates that the cable connect to switch is a straight line; (To Node) indicates the cable connect to switch is a cross-line;

e. One side of some transceivers with MPR switch: Indicates the cable connect to switch is a straight line; DTE switch indicates the cable connect to switch is a cross-line;

2.If the fiber optic cable, fiber jumper has been broken?

a. Cable on-off detection: using laser flashlight, sunlight, light to against one side of cable connector or coupler; see at the other end if there is visible light? If there is visible light, it indicates that the fiber optic cable is not broken.

b. Fiber optic connection on-off detection: using laser flashlight or sunlight in front of one side of a fiber jumper, see at the other end if there is visible light? If there is visible light, it indicates that the fiber jumper is not broken.

3.Whether the half / full duplex mode is wrong?

One side of some transceivers with FDX switch: indicates full duplex; HDX switch: means half-duplex.

4.Using a optical power meter to test

The luminous power of optical transceiver or optical module under normal circumstances: multimode: -10db-18db; single mode 20 km: -8db-15db; single mode 60 km: -5db-12db. If the luminous power of fiber optic transceiver is: -30db-5db, then you can determine the transceiver has a problem.

Direct Attach Cables (DAC) are high performance integrated duplex data link for bi-directional communication. And a SFP+ Direct Attach cable, also known as Twinax cables, uses SFP+ MSA and copper "twinaxial" cable with SFP+ connectors on both sides, provides 10 Gigabit Ethernet connectivity between devices with SFP+ interfaces. SFP+ Direct Attach Copper Cable is expected to be the optimum solution for 10G Ethernet reaches up to 10 m.

How does SFP+ Direct Attach Copper Cable Compare With 10GBASE-T?

1.10GBASE-T commonly used for 10MB, 100MB and 1GB network connections, while SFP+ Direct Attach Cable only for 10Gigabit Ethernet Network. And 10GBASE-T also support much longer distances than SFP+ Direct Attach Copper Cable.

The concept of standard, structured cabling provides a long-term underlying foundation of transmission infrastructure that follows a base set of engineering rules. 10GBase-T retains and abides by this by operating over the installed base of twisted-pair copper cable already in place for lower-speed applications. 10GBase-T uses the same cabling-link-negotiating concepts as do 1GBase-T, 100Base-T and 10Base-T, providing a clear path of bandwidth upgradeability as needed, by leveraging the existing pair infrastructure. Within a rack, following link segment specifications, the same 10GBase-T copper twisted-pair cabling will enable use with earlier Ethernet generations - 10MB, 100MB and 1GB operation. To extend this further, this same copper twisted-pair cabling is utilized outside the equipment distribution area (EDA) zone, connecting with horizontal distribution area in the data center.

As a technology, 10GBase-T enables network managers to preserve their knowledge base of Ethernet transport while seamlessly upgrading bandwidth capacity from 1G to 10G rates. Additionally, network managers preserve their underlying investment in the maintenance of standard, structured cabling systems. But SFP+ Direct Attach Cable is supported only on 10G ports. Do not insert a DAC into a 1G port.

The IEEE 802.3an-2006 10GBase-T Ethernet Standard specifies operation over standard, structured twisted-pair copper cable up to 100 meters. In contrast, 10G SFP+ Direct Attach is limited to 10 meters, with a reach of five to seven meters more commonly available. SFP+ Direct Attach cables longer than five meters are exponentially higher cost compared to shorter cables.

2. 10GBase-T offers the ability to field-terminate, while SFP+ Direct Attach cables cannot be field-terminated.

As a standard, structured cabling system, twisted pair cables are a known technology to data center cable technicians. Twisted pair cabling offers the ability to field-terminate, as needed, clean lengths in less than a minute. 10GBase-T implementations enable just such a clean, structured cable infrastructure.

SFP+ Direct Attach cables, in contrast, cannot be field-terminated. SFP+ uses a passive twin-ax cable assembly and connects directly into a SFP+ housing; they are specially terminated at the vendor site and must be purchased at pre-determined lengths. This adds overhead to cable management inventory, while preventing a clean, efficient cable infrastructure design.

3.Power Dissipation of 10GBase-T is higher than SFP+ direct attach cable.

At a physical layer (PHY) device level, 10GBase-T power consumption, whether at full 100-meter reach or 30-meter short reach mode, will be higher than SFP+ Direct Attach, including the electronic-dispersion-compensation chip. A 10GBase-T PHY, at the device level, can consume anything from two to four Watts per port compared to two Watts per port for SFP+ Direct Attach.

SFP+ direct attach cables are widely used in varies condition for short distance 10G transmission, and 10GBASE-T works with Cat 6 and Cat7 cable that are commonly used for 1Gb network connections, which all have their own special applications.

After the 10Gigabit PON(Passive Optical Network), WDM(Wavelength-division multiplexing) technology entered into traditional TDM PON fields. In April 2012, standard organization FSAN(Full Service Access Network) determined the time and wavelength division multiplexed passive optical network (TWDM PON) technology became the preferred solution for next-generation passive optical network stage-2 (NG-PON2) architecture after10G PON. To better understanding WDM PON, I list the WDM technology below.

What Is WDM?

WDM is a method of combining multiple signals on laser beams at various infared wavelengths for transmission along fiber optic media. WDM system uses a multiplexer at the transmitter to join the signals together, and a demultiplexer at the receiver to split them apart.

WDM systems are divided according to wavelength categories, generally course WDM (CWDM) and dense WDM (DWDM). CWDM operates with 8 channels (i.e., 8 fiber optic cables) in what is known as the “C-Band” or “erbium window” with wavelengths about 1550 nm (nanometers or billionths of a meter, i.e. 1550 x 10-9 meters). DWDM also operates in the C-Band but with 40 channels at 100 GHz spacing or 80 channels at 50 GHz spacing.

CWDM multiplexer module allows multiple optical signals at different wavelengths to pass through a single optical fiber strand. The common configuration of CWDM mux/demux module is 2CH, 4CH, 8CH, 16CH, 18CH CWDM mux/demux module.

DWDM Mux/Demux Modules – DWDM Mux and DWDM DeMux are designed to multiplex DWDM channels into one or two fibers. 50G DWDM Mux Demux is used to provide 50G transport solution for DWDM networking system. The common configuration is 4, 8, 16 and 32 channels, and also has 40, 44 channels. These DWDM modules passively multiplex the optical signal outputs from 4 or more electronic devices, send them over a single optical fiber and then de-multiplex the signals into separate, distinct signals for input into electronic devices at the other end of the fiber optic link.

WDM PON

WDM PON uses multiple different wavelengths over a physical point-to-multipoint fiber infrastructure that contains no active components (PON). Each provides a dedicated wavelength channel at the rate of 1Gbps to each optical network unit (ONU). The use of different wavelengths allows for traffic separation within the same physical fiber. The result is a network that provides logical point-to-point connections over a physical point-to-multipoint network topology. WDM-PON allows operators to deliver high bandwidth to multiple endpoints over long distances.

TWDM PON

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. 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.

This type of TWDM PON system is valuable in a market where multiple operators share one physical network infrastructure. Coexistence with previous PON generations in the legacy ODN depends on the TWDM PON wavelength plan, reuse the XG-PON wavelength bands, redefine the C-band enhancement band to contain both the upstream and downstream wavelengths and mixture of both of these plans.

TWDM-PON standards are expected to complete in 2013, and a finished commercial system should see the light of day in 2014.

More information about TWDM PON, click here