Micro cables were developed out of necessity in the early 2000s when bandwidth demands and fiber requirements were escalating, and there was a lack of available or easily accessible space to install new optical fiber cables underground. Legacy conduits became critically congested with large traditional loose tube cables, driving the need for smaller cables with higher fiber counts that could be installed with less cost and disruption than a rip-and-replace solution.
Southeast Asia reported more than 370 million internet users in January 2018, with a 141% year-on-year mobile connectivity growth rate, supported by the expansion of broadband infrastructures in the region. The large and ever-increasing digital population has created a myriad of applications and tech innovations, but keeping up with growing bandwidth demand can be prohibitively expensive.
Congestion in legacy ducts cause deployment delays, extend mean time to revenue, and impact total cost of ownership. So how do micro cables and microducts help?
Maximize use of existing space
Micro cables are miniaturized stranded loose tube cables which are up to 50% smaller and up to 70% lighter than traditional loose tube cables. Miniaturization is a reduction of the buffer tube diameter and outer jacket, which is made possible by optical fiber. Such fibers feature a reduced coating diameter that enables highly efficient fiber packing during the cabling process, where high-density micro cables are up to 20% smaller than standard micro cables.
The buffer tubes each still contain the typical 12 colored optical fibers and maintain their SZ stranding. While functionally equivalent, micro cables are less rugged than traditional loose tube cables. For this reason, a micro cable is typically installed in a microduct: a miniaturized plastic conduit which can be used to subdivide internal duct space into smaller compartments.
Microducts are available in single or “bundled” varieties and can be installed into an empty, or even occupied, legacy subduct to optimize the use of existing space, while multipath bundles allow for flexible and scalable high-fiber-count, high-density cabling in new installations.
Cost-effective and efficient installation
Civil works can account for up to 80% of total broadband deployment costs and, due to the high cost of trenching and excavation (particularly in urban areas), deploying either a 1.25-in duct or microduct bundle would be equally costly at first. There would be little difference in the day one cost of deploying either a 144-fiber loose tube cable or a 144-fiber standard micro cable in a seven-way microduct bundle in a 3,000 ft. urban span.
Not only do micro cables enable simple and economical capacity upgrades, they also enable easier and more cost-effective installation. Though they can be pulled at low tension over short distances, micro cables are generally blown or jetted into microducts using air-assisted blowing machines. Due to the reduction in cable size, installers can use smaller, less-expensive blowing machines and air compressors, as compared with traditional loose tube installation apparatus.
In addition, 50% smaller cables also mean twice as much cable on a transportation reel or simply smaller reels, offering lower transportation and storage costs.
The installation process can be managed by as few as three installers: one to operate the blowing machine, another to pay-off the cable from the transportation reel, and a third installer to monitor the cable as it exits the microduct at the end of the span.
However, the true value of microtechnology is revealed upon performing a capacity upgrade beyond the initial 144 fibers. Adding loose tube capacity would require further excavation that would cost almost $120,000 and take up to 30 days to complete. In comparison, a micro cable increase would cost $6,000 to purchase and install a new 144-fibre micro cable into one of six vacant microducts. This process could be completed in a single day, and repeated up to five times before retrenching becomes a consideration.
Scalable and future-ready microduct architecture
Originally rising to prominence in the congested legacy networks of Europe, high-density micro cables now enable network operators in Southeast Asia to quickly meet future capacity demand.
The deployment of new optical infrastructure is traditionally expensive due to the high cost and long project timeline of civil works, but using microtechnology from day one means that costly and disruptive re-excavation can be postponed far into the future. Moreover, smaller, lighter cables translate to an easier deployment with a lower total cost, lighter equipment, fewer network components, and smaller installation crews.
Fortunately, by swapping traditional loose tube cables and standard ducts for miniaturized or micro cables and microducts, network operators can quickly and cost-effectively meet fiber demands and also provide unique, cost-effective deployment techniques for flexible, scalable upgrades in the future.
Paul Ng is carrier networks manager for SEA at Corning Optical Communications