Add more power to the new-gen data networks

Optical interconnects are revolutionising high-speed data transfer in the digital age making it critical for driving the telecom sector growth

The term “high speed” in the context of networks has referred to an ever-changing benchmark over the years. There is a significant variation in what is commonly understood. But one can reasonably expect such networks to deliver a data transfer rate of 1 Gbps or higher today. This varies from 100 Mbps for Fibre-to-the-Home (FTTH) networks to 10-100 Gpbs in enterprise or datacentre networks, and this expectation is only going to rise in the future.

Many factors determine the data transfer rate or the “speed” of the network – the medium of transmission, the distance of transmission, modulation formats and more. Focusing on the medium, wireless transmission is a must today but it needs a wired backhaul. These backhaul networks were traditionally made of copper wires that were installed over decades, but they are not capable of supporting the data transfer needs of today, leave alone the future. This is because the frequency of transmission over copper networks limits bandwidth, the maximum data-carrying capacity.

Long-haul networks were the first to use optical fibre starting in the mid-1980s, and this expanded to metro and access networks at the turn of the millennium.

Copper also has significant issues in reach, and struggles to transfer more than 10 Gpbs beyond 50 meters. In contrast, optical fibre uses a much higher carrier frequency and hence has a bandwidth that is many orders of magnitude higher. The low optical loss in fibres also allows high-speed transmission across tens of kilometres. This is why optical fibre has played a key role in shaping the Internet of today and it is replacing copper in nearly every aspect of the network, leaving copper to be used in certain cases that need its functionality; the simultaneous transmission of data and power, for instance.

Optical fibre has been steadily growing in terms of share of network deployment, capex spend and geographical reach. Long-haul networks were the first to use optical fibre starting in the mid-1980s, and this expanded to metro and access networks at the turn of the millennium. In the last decade, technologies like passive optical networks (PON) have become mainstream in delivering high-speed FTTH connections.

The optical interconnects

Recently, datacentres have started using fibre both inside their premises, and for interconnections between themselves. Optical fibre cable is one of two key elements in creating these networks. The other is optical interconnects.

The term “optical interconnects” can cover a range of products. Among active components that need power, they can include optical transceivers, multiplexers and demultiplexers, optical switches and more. On the passive side that doesn’t require power, it includes optical connectors, splitters, closures, junction boxes, cabinets, racks and more. These are the points where optical cables are terminated, handled, split or spliced when networks are deployed, and they are also the points where signals are transmitted and controlled in an actively operating network.

While optical fibre hardly varies by geography and operator, optical cables vary a little more because of varying needs for network capacity and deployment scenarios. However, optical interconnects have a large variation both in terms of geography and the choices of a network operator because they cover a larger range of requirements. The examples include capex needed for deployment, installation practices and the availability of skilled labour, operating expenses, and future-proofing needs and flexibility. This complexity of market needs has driven growth in the optical interconnect industry.

The industry can expect a lot of innovation in the optical interconnect industry, driven by operators’ key needs. The first is interoperability with existing and future products. This requires the industry players to come together in setting common standards, as opposed to proprietary solutions that may lock an operator into a single vendor. This often leaves them worse off despite the early advantages offered by the innovation.

Many factors determine the speed of the network – the medium of transmission, the distance of transmission, modulation formats and more.

Secondly, innovation in optical interconnects will likely have a two-way benefit with corresponding advances in optical fibre and cable, where integrated fibre-cable-interconnect players are expected to lead the way. The industry can also expect that innovation will arise from the convergence of networks, the emergence of edge computing and datacentres, and more.

High-speed data networks are already all around us. Their scale, capability and reach are expected to continue to grow for a long time. Emerging trends firmly point to a future in which both the volume and the speed of networks are expected to scale significantly and constantly. One example – the recent excitement around AI shows how much headroom there is for such growth.

Optical fibre and interconnects are essential to driving this growth, and for the future of telecommunication.

By Jitendra Balakrishnan

Jitendra is the CTO of Optical Business at STL

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