What Are MPO and MTP® Cables

There comes a more demanding request for higher transmission speed and larger capacity with the prevalence of cloud computing in the era of big data. 40/100G networks are increasingly becoming more commonplace in data centers. As an alternative to MPO cables, MTP® cables with better performance have been the inevitable trend in data center cabling. MPO vs MTP®, what are the reasons that make the latter overmatches the former? Why should we choose the “winner” MTP® cables as the first choice?

What Are MPO and MTP® Cables?

MPO (Multi-Fiber Push On) cables are capped with MPO connectors at either end. MPO connector is a connector for ribbon cables with at least 8 fibers, which is designed to provide multi-fiber connectivity in one connector to support high bandwidth and high-density cabling system applications. It is compliant with the IEC 61754-7 standard and the U.S. TIA-604-5 Standard. At present, the most common fiber counts are 8, 12, 16, and 24. 32, 48, and 72 fiber counts are also possible in limited applications.

MTP® (Multi-Fiber Pull Off) cables are equipped with MTP® connectors at either end. MTP® connector is a trademark by US Conec for a version of the MPO connector with improved specifications. So MTP® connectors are fully compliant with all generic MPO connectors and can interconnect directly with other MPO based infrastructures. However, the MTP® connector is a multiple engineered product enhancement to improve mechanical and optical performance when compared to generic MPO connectors.

MTP® vs MPO Cable: What Are the Differences?

The key difference between MTP® and MPO fiber optic cables lies in their connectors. As the improved version, MTP® cables equipped with MTP® connectors have better mechanical designs and optical performances.

MTP® vs MPO: Mechanical designs

Pin Clamp

MPO connector is usually equipped with inferior plastic pin clamps, which may lead to effortless breaking of pins with constant cable mating, while the MTP® connector has a metal pin clamp to ensure a strong clasp on the pins and minimize any inadvertent breaking when mating connectors. In the MTP® connector, the oval spring is used to maximize the gap between fiber ribbon and spring, which can protect the fiber ribbon from damages during inserting. The MTP® design includes a recessed pin clamp and oval spring will ensure a secure spring seat, and greater clearance between the spring and the ribbon cable in order to reduce the risk of damage to the cable.

Figure 1: MTP® vs MPO Cable Pin Clamp

Floating Ferrule

The floating ferrule is adopted in an MTP® cable design for improving mechanical performance. In other words, the floating ferrule of the MTP® connector can float inside to keep physical contact over a mated pair under an applied load. However, the MPO connector is not manufactured with the floating ferrule. The floating ferrule feature was particularly important for applications in which the cable plugs directly into an active Tx/Rx device, and was one of the primary reasons that the MTP® became the connector of choice for emerging parallel optics Tx/Rx applications.

Guide Pins

Unlike single fiber connectors, the adapters for multi-fiber connectors are only for coarse alignment. Thus the guide pins are critical for accurate alignment when mating two MT ferrules. The guide pins adopted by MTP® and MPO connectors are also different. The MTP® connector uses tightly held tolerance stainless steel elliptical guide pin tips to reduce the amount of debris that may fall into the guide pin holes or on the ferrule end face. However, the chamfered shaped guide pins adopted by MPO connectors will produce more debris when used.

Figure 2: MTP® vs MPO Cable Guide Pins

Removable Housing for MTP® Cable

When comparing between MTP® vs MPO, their housing removability is one of the important factors. The MTP® connector is designed to have a removable housing which allows users to re-work and re-polish the MT ferrule and easily get access to performance testing and to smoothly change the gender after assembly or even in the field. There is an MTP® cable called MTP® PRO cable that can allow quick and effective cable gender and polarity reconfiguration in the field while ensuring product integrity and performance.

Figure 3: MTP® Cable Removable Housing

MTP® vs MPO: Optical Performance

Insertion-loss

The MPO connector has been recognized as an international standard in network architecture for many years. MTP® connectors, as the advanced version, are improved to minimize issues like optical loss, dropped packets, and so on. MTP® connectors in MTP® cables are designed to ensure precision alignment of the male and female sides, which will help to reduce the insert loss and return loss when transmitting the data in high-density cabling systems. Furthermore, MTP® insertion loss rates have continued to improve, now rivaling loss rates that single-fiber connectors saw just a few years ago.

Reliability

Compared with the previous MPO cables, the latest MTP® cable formats can plug in without problems, which are less likely to have accidental bumps that may result in signal instability. The internal connector components were redesigned in the MTP® format to ensure perfectly centered normal forces between the mating ferrules, ensuring physical contact of all polished fiber tips in the ferrule. Besides, the lead-in on the precision alignment guide pins to an elliptical shape has also been optimized, reducing the wear and tear and debris generation from plugging and re-plugging the connector multiple times. These additional improvements to the precision of MTP® connector components resulted in increased stability and boosted durability performance while continuing to enhance the connectors’ overall reliability.

Future Trends of MTP® Cables

With the 20-plus-year history of endless improvements and the next generation of advancements soon to come, the MTP® connectors allowed multi-fiber connectors to provide even more consistent, reliable performance. As an optimal solution designed for the trend of a high-speed, high-density, and well-organized cabling, the MTP® connector scales to new parallel applications such as 400G Ethernet capable of running across 32, 16, and 8 fibers. With robust engineering, MTP® connectors have also been widely adopted in a wide range of operating environments, including those with high humidity, extreme heat and cold, and fluctuating temperatures.

MTP® cables also deliver exceptional value for a vast range of network technologies, which is not just built for the mega-cloud, big data, and hyper-scale computing. The latest versions of MTP® connectors are designed to work not only with actual fiber-to-fiber connections but with other technologies across many vertical industries covering financial, medical, educational, colocation, and so on.