cable isp hfc,why replaced coaxial?

[sarahr202]

Hi everybody

Below is the the picture showing how the the bandwidth of co axial is shared .

The traditional cable isp was using co axial cable to provide internet plus tv channels.

Head end-----coaxial---distribution-----coaxial----homes.

I did not show the amplifier used to boost the signal.

Now cable isps are using fiber and coaxial which is commonly referred as HFC.

headend-----fiber----distribution----fiber-----node----coaxial-cable.

Here is my question why are we using fiber above? If huge bandwidth offered by fiber is the reason then what is  the point because we are using coaxial at customer end.  No matter how much bandwidth fiber offers, the co axial'sbandwitdth( IGHZ) will be the limiting factor.

I could understand some of  the reason why we want to use above ( low EMI, fewer amplifers needed, longer distance etc)

thanks and have a great day.

[Manuel Rodriguez · Accepted solution]

Hi Sarah,

Indeed, the main advantage is not BW. The main advantage of using fiber is that, basically, it allows to reach out greater distances with better signal quality. As you may know, fiber is, in general, a better transmission media than coax (even though coax is a good media itself). Some advantages:

- Less atenuattion.

- Light is immune to EMI and RFI interference.

- Fiber has become easier to deploy given it's light wieght.

- Current technology is making it easier to install and deploy optical fibers quickly and reliably.

- Cost of fiber has become quite attractive.

Hope this helps.

Best regards.