MPO/MTP High Density Fiber

MPO/MTP high-density optical fiber pre-connection system is currently mainly used in three major fields: application in high-density environment of data center, application of optical fiber to the building, connection application in optical splitter, 40G, 100G SFP, SFP+ and other optical transceiver equipment . This article focuses on why data centers use MPO/MTP high-density fiber pre-connection systems and how to choose this high-density fiber pre-connection system.

Data center MPOMTP high-density fiber pre-connection system

There are two distinct stages of development for fiber optic connectors:

The first stage: In order to save space and develop towards miniaturization, fiber optic connectors are developed from traditional FC, ST, SC to LC, MTRJ, E2000

The second stage: not only to save space, but also to meet the requirements of multi-core use, the optical fiber connector has evolved from LC, MTRJ, E2000 to MU, MTP/MPO, and now a MTP/MPO multi-core connector can meet 2-core, 4-core , 8 cores, 12 cores, 24 cores, currently up to 72 cores

The application of the MPO/MTP optical fiber pre-connection system in the data center has only happened in the past few years, and it is also the most important application occasion of the MPO/MTP pre-connection system in China. The reason is not as noble as imagined, but it is actually an inevitable choice. Let’s talk about the first reason: there is always not enough space in the data center. Just like in some places, the subway is built for half a year, and the passenger flow is full. This is actually a pair of contradictions between limited resources and unlimited demand. This phenomenon is reflected in various fields in China at present. The solution to the lack of space can be to increase the space or improve the utilization rate of the space. It is unrealistic to increase the space in a well-designed data center. To improve the space utilization rate is to increase the density.

As the two major wiring systems in the data center: copper cable and optical cable wiring system, in fact, copper cable system can also use high density, but the space saving of this high density is really limited. Because it is not only impossible to find a balance between satisfying high frequencies and a larger wire diameter; the electrical transmission performance of cables at high frequencies is also not easy to meet, and it is necessary to solve the problems caused by high-frequency electronic signals in multi-core copper cable transmission. a series of questions.

Of course, for on-site installation of a convenient and convenient copper pre-connection system, this is another topic, which is ignored here. Therefore, in order to obtain more transmission bandwidth in the same space, it is an inevitable choice to switch to optical fiber transmission, but this does not mean that a high-density optical fiber pre-connection system is necessarily required.

The second reason is the result of the continuous improvement of network speed. As far as optical fibers are concerned, dual-core fibers can support 100M, 10G and 10G applications, but do not use special codes and protocols. Two-core fibers support 40G and 40G. 100G becomes difficult. Fortunately, more than 200 experts in the IEEE working group have put forward a standard to support such applications after years of hard work, which is now known by many people as the IEEE802.3ba specification.

Studying this 457-page specification standard, it is easy to find the definition of optical fiber cabling transmission in it, see the figure below. We can see that a single channel is 4-core or 10-core fiber, so the normal 40G and 100G fiber network communication is 8-core fiber and 20-core fiber. This poses a challenge to the traditional dual-core optical fiber transmission for data communication, that is, high-density multi-core optical fibers are required, but even this does not necessarily require the use of high-density multi-core optical fiber pre-connection systems.

Let's look at the third reason. This reason is more realistic, that is, the original fiber optic connectors that everyone is familiar with, such as SC and LC, cannot meet the MDI multi-core requirements defined in this high-speed network standard in terms of number of cores and miniaturization. . In addition, it is very difficult to complete the multi-core connection of such a single optical fiber on site, because the failure of one core means the failure of the entire fiber.

At the same time, it is difficult to obtain a complete guarantee of performance and it is difficult to meet the requirements of performance consistency. It is an inevitable choice to transfer such complex work on site to a special factory with assembly lines and various equipment. Although this poses some challenges to the traditional data center cabling system, it is mainly manifested in the design stage and the site survey and calculation stage. It is necessary to determine the location of each cabinet and calculate the exact length of each Trunk optical cable so that the factory can schedule production.

But this work is really nothing for such a high-performance fiber optic cabling system for high-speed networks and the possible performance uncertainty brought about by on-site construction. In fact, this is also a way to change our traditional wiring thinking mode. In fact, many industrial products can be prefabricated in the factory. Lego in the toy industry and IKEA in the furniture industry may have already grasped this idea.

The fourth reason, which is the relief of system integrators, is also a matter of user satisfaction. Because of the high-density pre-connection system, it can greatly reduce the installation time on site, and also greatly reduce the impact of on-site construction and installation on performance and the probability of performance uncertainty. It not only greatly reduces the difficulty of construction, but also has more guaranteed performance, and also greatly reduces the installation space of the wiring system. So it is not surprising that it is widely used.

So how to do a good MPO/MTP high-density optical fiber pre-connection system project? Of course, we must choose high-performance. However, the author has been emphasizing that the performance of a wiring engineering project depends on four important factors for many years: the preliminary design, product performance, installation process and project environment. In a traditional non-pre-connected cabling system project, the impact of the four elements on the final performance of the project can basically be considered as 25% each.

However, in the pre-connected system, this ratio will change greatly. Due to the large number of on-site installations in the project, the termination work is transferred to the pre-connected products in the early stage. At the same time, the results of the length calculation in the design phase will also be implemented in the factory, so it is not an exaggeration to say that the performance of the pre-connected products will account for more than 50% of the final performance of the project. Such a situation would make work in a pre-connected factory even more critical.

So how is the performance of MTP/MPO high-density optical fiber pre-connection system products guaranteed in a production factory? What is the difference between it and ordinary optical fiber patch cords, distribution frame assembly and production?

First of all, this production plant must comply with a series of quality management system certifications such as ISO9000. At the same time, the production process and product performance must also comply with the most comprehensive and strict standard certification for the production of optical fiber connection components in the industry, such as the GR326 standard. There are many factories that can produce fiber optic patch cords, but very few are certified to the GR326 standard developed by Telcordia. Telcordia, formerly known as Bell Communications Laboratories, is committed to the development of US standards, including writing US /Global standard. For example GR326.

Secondly, it is necessary to understand the MTP/MPO pre-connection system products, whether it is Truck or polarity module, whether it is Hardness or MPO jumper, the processing technology is far more complicated and difficult than conventional SC and LC connectors. Processing a 12-pin MPO connector It is not just a simple superposition of the workload and difficulty of processing 12 simplex SCs or simplex LCs. It cannot be done without advanced equipment, exquisite craftsmanship and years of experience and well-trained personnel.

The requirements for consistency and repeatability are extremely demanding. As a simple example, the height of the optical fiber of the ferrule of a 12-core MPO/MTP connector is required to be several thousand nm. It is more difficult to ensure that the difference between these heights is less than a few hundred nm. It comes from the performance requirements of 40G and 100G optical fiber networks on the physical link layer. Looking at the Chinese market, according to the author's understanding, there are only a handful of factories that can specialize in the production of MTP/MPO high-density optical fiber pre-connection products, and even fewer are capable of mass production. The company's Verizon-certified EPCOM is one of the few.

In conclusion, this paper discusses the reasons why the data center adopts the MPO/MTP high-density optical fiber pre-connection system, and puts forward some suggestions for the selection of this new system. helped.