By Jay Tourigny, Senior Vice President, MicroCare, LLC
The race to build 5G networks has never been more important. This has been highlighted as the world relied on consistent connectivity to communicate, learn and work through the COVID-19 pandemic.
This fifth-generation robust wireless technology has the power to support millions of devices with superfast speeds and higher data volumes than the generations before, a must in today’s connected world.
5G is used everywhere from the video calls in the home office to the SMART equipment on the factory floor. From real-time data used in transport networks, to autonomous machinery in the farmer’s field. 5G connectivity allows existing applications to be carried out quicker and more reliably.
Faster and more stable all-fibre 5G networks are replacing traditional coaxial or copper core cables since a new and updated network infrastructure must be in place to support the increasing traffic, numbers of devices and data.
For 5G networks to effectively handle all this data and seamlessly stream the increased bandwidth, reliability is key. As 5G connectivity rolls out to more areas in Europe, network providers must ensure fibre is installed and maintained correctly with all connections kept perfectly clean for optimal performance and reliability. Without the implementation of cleaning procedures to guarantee optimal network operation, uninterrupted connectivity and high-speed operation can be affected.
Don’t let contamination threaten network reliability
Contamination is the number one threat to 5G network reliability. It is a removable impurity on the connector end-face and includes everything from lint and fingerprint oils, to moisture and simple dust.
A contaminated cable end face can block the light through the fibre changing the index of refraction or the path of the signal. If the contamination is very severe, the refraction angle can change enough that the signal can be completely lost and a total network shut down occurs.
New, faster 5G networks have a higher frequency of light making them more sensitive to changes of the refractive angle, thus, more vulnerable to contamination. Even the smallest microscopic particle can be disastrous for 5G. It has to be able to use every megawatt of power to ensure optimum connectivity and performance is met.
The effects of dust
Dust-based contamination originates from many sources. Airborne dust can come from vehicle emissions, cardboard boxes, construction dust, and even lint from clothing. Dust particles can become embedded into the ferrule surface, resulting in pitted, scratched or scarred end faces. Therefore, all fibre end faces must be thoroughly cleaned during installation or maintenance operations to prevent 5G network interference or failure.
Ironically, dust particles can come from the very tools being used to clean the fibre. Poorly engineered foam swabs, lint-prone paper-based wipes, and low-purity cleaning fluids used by some installers can cause or exacerbate the problem.
Another source of dust contamination is connector-wear debris caused by contact friction when connectors are mated. This is a common cause of dust-based contamination and it is the reason why cleaning brand new fibre cables straight out of the pack is so important.
Jumpers and patch cords, even when new from the supplier, cannot guarantee cleanliness. The end caps used to protect the endface after manufacture and during transport are typically not cleaned. This means dust and other leftover production debris could be trapped inside the sleeve and migrate to the end face.
Some cable manufacturers also use mold-release agents to help eject the end face cap or housing from their molds during manufacture. Residual release-agent inside the end caps can transfer to the connectors. Outgassed plasticisers from the protective plugs on the end caps are well-known to leave oil on the end-faces.
5G networks require vast amounts of new fibre cables, but they are not pristine clean and ready to use straight from the box. Installers should always thoroughly clean both ends of the connector pair before they are mated to ensure clean fibre connections.
A static problem
Because a dust particle can be minuscule, on average just 2.5 microns in diameter, it can easily be locked into place on an end-face by an electrostatic charge. Static buildup can have a huge effect on the performance of the fibre. When two different materials are rubbed together, for example, a dry paper wipe on a fibre end face, the friction causes an electrostatic charge to develop on the connector. This causes dust particles to migrate into the contact zone of the mated ferrule pair. Because fibre connectors are made with dielectric materials, they act as an electrical insulator. This means the static charge has no place to go and can remain indefinitely on the end face and continually attract dust particles. This is a huge reliability risk for 5G networks.
To stop contamination caused by electrostatic charge it is recommended that a wet-to-dry cleaning method is used. Water or isopropyl alcohol are common choices, but they are hard to buy in high purity packaging, slow to dry and difficult to keep clean and uncontaminated during day-to-day use. An optical-grade cleaning fluid dispensed from a hermetically sealed container is a better option. It will remove the contaminant, dissipate static and eliminate triboelectric charges that attract dust particles and cause them to stick to a connector end face.
Choose your tools wisely
Thanks to its fast-drying properties, optical-grade fibre cleaning fluid reduces cleaning time and prevents moisture in the atmosphere from being attracted to the fluid, therefore reducing possible contamination. Furthermore, it is non-flammable and non-hazardous, making it safe to store and easy to transport.
When using optical-grade cleaning fluid, insist on high-grade wipes that do not lint or generate a static charge in use. Optical-grade wipes are designed to be soft enough not to scratch the ceramic or composite ferrule end face and are highly absorbent for wiping the contamination away from the surface of the end face. It is important to ensure the wipes are in sealed packages to keep them pure and clean prior to use.
When cleaning fibre, always inspect the termini on both ends of a connector pair first to visually identify the level of contamination. Then using the wet/dry cleaning method, dispense the static-dissipative cleaning fluid onto a section of an optical-grade cleaning wipe. Wipe the connector end-face starting at the damp area and moving in one direction towards the dry area of the cleaning wipe. This removes the contamination and dissipates electro-static charges in one step. Follow this by re-inspecting to ensure the fibre is contaminant free.
Stick and clicker
Alternative cleaning tools include mechanical clicker style devices or sticks for use on connectors recessed in couplers. Clicker tools are quick to use and good for applications with light levels of contamination. However, they may not be ideally sized for cleaning termini in hardened connector housings. Fibre cleaning sticks on the other hand are specially developed to effectively clean heavily contaminated end faces. When used with static-dissipating cleaning fluid, they are perfect for cleaning connectors mounted in hard-to-clean alignment sleeves.
Because cleaning sticks effectively make contact with the end-face configuration, they can clean the entire end-face without the need to disassemble the connector or adapter. They give the largest effective cleaning region on the entire surface eliminating problems associated with contaminants migrating into the signal path. The cleaning fluid also serves to effectively create a dissipative path removing any static charge prior to mating the connector.
A cleaning stick should be engineered specifically to match the configuration and size of the end-face and be non-linting for optimal cleaning. When using the stick, it is important to only rotate in one direction; typically 6 rotations in one direction is enough to remove any contamination. Importantly only use one stick per end-face to avoid cross-contamination.
Again, use the ‘Inspect-Clean-Inspect’ rule. If the final step of re-inspection is not followed there is a risk of leaving contaminants on the end-faces. This can reduce the 5G signal strength and cause reliability problems. The knock-on effect being time-consuming and costly rework and repairs and delays in installation.
Cleaning ensures long-term 5G reliability
Reliable 5G networks are critical to enabling innovation and digital transformation. ‘The future of telecommunications and computing infrastructure connecting billions of users and trillions of devices is requiring more efficient technology to be able to overcome exploding traffic and properly address security issues.’ cited the European Commission. ‘This revolution will rely on a common global definition of 5G and associated standards, and of its service characteristics. Only then can we ensure seamless optical and wireless connectivity.’
To accelerate 5G in Europe and meet the connected ‘revolution’ goal, it is essential to implement well-engineered cleaning processes and standards. Successful cleaning must be achieved not only during network deployment and upgrade, but continue during future infrastructure maintenance. Without specific cleaning processes in place reliability will be compromised and an interconnected 5G future will be at risk.
By ensuring cleaning standards at met; the correct fibre optic cleaning fluids, tools and methods are used; and installers are fully trained in the required process; 5G networks can perform as they should and keep us reliably connected.
Jay Tourigny is Senior Vice President at MicroCare, LLC, which offers Sticklers brand fibre cleaning solutions. He has been in the industry more than 30 years and holds a BS from The Massachusetts College of Liberal Arts. Tourigny holds numerous U.S. patents for cleaning-related products that are used on a daily basis in fibre optic, medical and precision cleaning applications. For more information, visit www.sticklers.com