sensing-fibre

There is no question that online communication via the medium of fibre optic cabling is our future. The fibre optic communication industry has been enjoying great growth for the past decade. In 2010 the global demand for fibre optic cable reached 182 million fibre-km*. This growth has been driven by both technological advances hitting the marketplace, and market demand e.g. China.

Along with its significant increase in connection speed, fibre optic cabling also offers a tremendous capacity to keep up with any new technological advances. This is due to the fact that once the basic fibre optic infrastructure is in place, it can be rearranged; enabling the end point electronics to be upgraded when necessary, in order to deliver even higher capacity.

Many believe that fibre won the war over copper years ago, among telecom service providers in long haul, metro and residential networks. Indeed, fibre is now taking over mobile networks where it handles backhaul chores today.

Only fibre, with its long reach, reliability, space savings, immunity to interference and relatively low cost, can help both public and enterprise operators control their budgets. Whilst also delivering high quality services at even faster speeds.

Fibre will dominate enterprise networks, just as it does in today’s public networks. This is since fibre will serve most access points and radio based stations in the near future, whether an enterprise user connects to the network via mobile or fixed line device. Fibre optics will carry the majority of the traffic.

To support the changing and fast-growing bandwidth needs of the Data Centre, the IEEE ratified standards for supporting 40 Gigabit and 100 Gigabit. Both single mode Fibre and OM3 and OM4 multimode fibre (OM3, OM4) were approved in the standard. Today 40Gbs Multimode uses parallel optics with MPO interconnects and requires additional cable infrastructure depending on the system deployed, while single mode fibre will use LC or SC connectors. However, Cisco has announced a new technology for deploying 40G Ethernet that has, so far, received little attention.  Cisco calls that technology BiDi.

BiDi stands for “bi-directional”.  BiDi uses two different wavelengths on the same fibre, with one wavelength going in one direction and the second wavelength moving in the opposite direction.  The advantage with Cisco’s 40G BiDi is that it can use the same duplex MM 10G infrastructure to implement 40G Ethernet.

10G Ethernet (10GBASE-SR) uses duplex fibre with LC connectors, in order to transmit on one of the fibres and receive on the other fibre.  40G Ethernet (40GBASE-SR4) uses 8 multimode optical fibres: 4 to transmit and 4 for receiving.  This requires the use of 8 cores, but the products used are 12-fiber trunks and patch cables terminated with MPO/ MTP connectors. So with 40G Ethernet only using 8 out of the 12 fibres in a 12-fiber trunk, when migrating from 10G to 40G Ethernet, we have unused infrastructure. There is also a cost with discarding MPO to LC cassettes and moving to couplers.

BiDi offers an alternative way to deploy 40G Ethernet that meets the 40GBASE-SR4 performance requirements. BiDi provides 40G Ethernet on two multimode fibres and duplex LC connectors, the same as the existing 10G infrastructure that is deployed today.  With 40G BiDi, migrating from 10G to 40G is easy – just replace the existing 10G optical modules with 40G BiDi optical modules.  There is no need for expensive MPO couplers, discarding expensive cassettes, or additional fibre infrastructure.

In truth, Fibre Optics are here to stay and will remain at the forefront of all cabling infrastructures for the foreseeable future.

*provided by Integer-Research

Leave a Reply