Kevin Lengle, Product Line Manager with Cailabs, looks at how multimode fibre local networks can be upgraded to meet the growing demand for bandwidth. He brings his expertise in optics and telecommunications to the development of innovative optical solutions to fully exploit the potential of multimode optical fibres.
Most local area networks (LAN) use multimode fibre (MMF). I will dispel some myths about the capacity limitations of multimode fibres by presenting an innovative technological approach to increase the bandwidth of existing multimode networks.
The implementation of new services in campus networks is exploding total demand for data. However, most of the inter-building cabling infrastructures of these networks are composed of 62.5/125 µm or 50/125 µm multimode fibre (OM1 to OM5 fibre). Multimode fibre has limited bandwidth (due to modal dispersion) and cannot support throughputs of 10 Gb/s or more, currently required by campuses-wide links. This especially applies to first generation OM1 and OM2 multimode fibres, on which a 10 Gb/s throughput can only travel up to 33m and 80m respectively. So, is it possible to magically transform legacy multimode fibres into single-mode fibres to meet the growing demand for bandwidth in local networks? You may be surprised to know that the answer is yes!
The conventional solution has been to replace the old cabling with next generation fibre. However, redeploying fibre cable is often a difficult task that has significant impact on business activities. In some cases, micro-trenches or more invasive work in general, may be required to install the new cables throughout the campus. Replacing cables can therefore require tedious installation work with complex project management and exorbitant costs. Fortunately, optical technologies have evolved and there is now an alternative to complex fibre network deployments.
The recent introduction of a range of innovative off-the-shelf solutions means that the speed and distance limitations of multimode fibre can be overcome and throughputs of up to 100 Gb/s can be carried over existing multimode infrastructure for up to several kilometres. This is of great benefit for campuses, as it now enables the gradual and flexible evolution of the local network’s optical infrastructure. These solutions are interoperable and compatible with any type of multimode fibre, thus helping to preserve existing network infrastructure. These innovative solutions are passive (i.e. no power consumption, configuration or monitoring required) and operate at the physical layer level, which makes them transparent to the wavelength, communication protocol and modulation format used. This provides an opportunity to implement wavelength division multiplexing (WDM) technologies on MMF where necessary, to perform single-mode/multimode media conversion functions passively, or to deploy GPON within a Passive Optical LAN architecture on MMF.
This new disruptive approach has already proven its effectiveness across numerous industrial, military, university and hospital campuses around the world. As a valid alternative to complex recabling, these technological innovations make it possible to solve the campus network bandwidth problem in a practical, economical and environmentally friendly way, with proven benefits for end customers and ICT professionals alike.Click below to share this article