We left off our previous blog at the daunting question: How do we accommodate 5 ZB of data consumption per year?
Fundamentally, data travels as signals (or packets) of light in the fibres. In a single fibre, there are multiple wavelengths of light carrying different sets of data. So there are basically 2 ways of increasing the data transfer capacity:
- Increasing the wavelength spectrum used for data transmission
- By using reduced water peak fibres
- By using longer wavelengths of fibres (>1550nm)
- Increasing the number of fibres in a single cable.
Let’s look at each solution individually:
- Increasing the wavelength spectrum used for transmission
- By using reduced water peak fibres: The below diagram clearly shows how A2 category fibres are able to utilise the E-band wavelengths (water absorption spectral region) by keeping the signal losses within the permissible limit as compared to D category fibres. This gives the benefit of 100nm extra transmission capacity. That translates to a 33% gain in the CWDM transmission with 4 additional channels.
- By using longer wavelengths of fibre: The challenge faced while using longer wavelengths is the increase in attenuation but more importantly the signal loss at bends which in fact is a big concern because in the real world wires aren’t going to be straight parallel lines drawn on a map. The wires need to bend at various points to reach the final end user. We developed state of the art technology, BOW LITE (E). With this technology, the bend losses were reduced by 99.75%, from 4dB in legacy G.652.D cables to 0.1dB in G.657.A2 (BOW LITE (E)).
But how did we achieve this? We added a new layer to our cables, which increases the difference in the refractive indices of the core and the outside, this helps in with the internal reflection of light hence keeping it inside the core meaning no signal lost. This is how we have drastically reduced the data loss at bends even for longer wavelengths of light.
The above graph clearly shows that the A2 fibres don’t discriminate on the basis of colour (of light), The bend losses are kept low at higher wavelengths allowing higher data transfers.
Other benefits of using A2 fibre is that due to the decreased bending loss, the network reach increases by 16km and enables higher splitting ratio.
A major concern related to adoption of A2 fibres would be the splice compatibility with D fibres because of the current widespread use of it. Our research while splicing G.652.D and G.657.A2 fibres, shows a mere 0.054dB splice loss operating at 1310nm wavelength and an even less 0.045dB loss at 1550nm. Such low values clearly depict that the A2 fibres are splice compatible with D fibres.
Another factor to take into consideration would be the longevity of the cables. Owing to its low bend losses and attenuation the network lifetime shows an increment of a minimum of 10 years, and extends the time taken for optical loss threshold/ link attenuation to reach ‘2x beginning of life (BOL)’ value making it even more cost effective in the long term.
2. Increasing the number of fibres: The challenge with increasing the fibre capacity is the limited diameter of the ducts and limitations during storage, transport and installation. Solution? Reducing diameter of fibres from 250 microns down to 200 microns as well as increasing the packing efficiency of the cable with our new Micro cables having 432 Fibres in a mere 8.6mm diameter. That translates to 59% less area with 6 times the fibres as compared to conventional cable with had 72 fibres in 13.5 mm diameter.