High fibre: multicoloured data transfer

PACKETS OF communications data – whether for phone calls, e-mails, or music, video and text files – are increasingly transported using fibreoptic cable rather than old-style copper cable. Data is carried by laser light sent through the thin optical fibres.

Because (as is seen when a rainbow forms) “white” light is actually made up of different colours, each a slightly different wavelength, a fibre cable can carry data on eight wavelengths/colours, increasing the cable’s capacity. This is called wave division multiplexing (WDM).

Currently, a separate laser has to be calibrated for each colour carried on a cable, and lots of switches must be attached to manage how data traffic is divided up into smaller packets, directed over networks, and reassembled as it enters and leaves the servers that connect fibre networks across the globe. Along the way, packets of data generally get lost or delayed – which makes for poor playback of a YouTube video or sound file, for example.

Packet loss also means carriers cannot guarantee quality of service very easily for businesses – at least not without reserving lots of extra bandwidth capacity and leaving it idle except for the odd occasion that it is required.

The breakthrough claimed by Dublin company InTune Networks is to have created a system of tuneable lasers, where a single laser can be retuned to different colours on the fly, in microseconds. So, a single laser can do the job of eight, and lots of bandwidth can be reallocated instantly if needed and then reassigned after use for a large transfer of data. It’s a bit like a gate efficiently directing car traffic down a highway so that there are no backups or delays.

In addition, intelligence built into the system eliminates the need for most switches, and allows every data packet to be sent directly to its destination IP address and monitored through its travels.

Therefore, InTune says quality of service can be guaranteed, capacity is available on demand, significant costs and infrastructure can be removed from networks. There is a green dividend too as about 75 per cent of energy use and cost is in the switches and multiple laser controllers.

If the systems work in live networks as planned, InTune will have solved one of the major problems in managing networks generally, and in providing high-bandwidth services like video on demand to consumers.