Ethernet started as the shared copper medium (cable) technology. As data speed increased from 10Mbps to 1Gbps, then Ethernet no more remained the shared medium and required point to point inter-connect. Ethernet switches are used to have LAN implemented when going to from shared cable to dedicated link. Fiber became one of the medium for Gige Ethernet and became medium for choice for longer distance (more than 300 meters) upto 80 Kilometers. Fiber was the first medium for be used for 10GE.
Now copper is also supported for 10GE, but it is limited in distance (150m) and requires higher powers. Hardware chip companies are struggling to lower down the power of 10GE copper solution. Still copper is the major share for Ethernet interfaces, but looking at the trend, I think Fiber will replace the copper as Ethernet medium of choice.
Let us first look at the pros/cons of Fiber vs. Copper and argue the prediction. As the speed of Ethernet is going up, then Copper Pros started to become less attractive and Cons are becoming prominent.
Pros for copper (Cons for Fiber) are
* Infrastructure install base i.e. existing cabling and equipments: Existing cables can not support higher Ethernet speed and would have to be replaced. So rather than putting new copper cables, one can put fiber. Fiber can easily support higher speed in future than copper.
* Easier to use and manage and require less technician training: Copper does not require special cleaning as normally in fiber. So copper has lower Opex.
* Cheaper: As Ethernet speed goes up, copper price advantage is waning down. Hardware for higher speed becoming more complex and expensive and need better cable. Even with better cable distance is limited. So all these factors cutting price advantage.
* Interconnects are passive. Cables lengths can be extended with passive interconnect.
Cons for Copper (Pros for Fiber) are
* Higher power: This is even becoming worse with the increase of Ethernet speed. Hardware needs to implement complex logic to support higher speed Ethernet, which in turn increase the power consumption.
* Cables are bulkier compared to fiber: Going to get worse with higher speed.
* Hardware is getting more complex for higher speed, so limiting the speed scalability
* Shorter distance inter-connect and getting shorter for higher speed
With the increase in Ethernet speed copper is loosing it charm. Also at the same time technological innovations are happening in the fiber space. For example Luxtera Inc (www.luxtera.com) has developed photonic silicon to integrate optical components into silicon. Corning (www.corning.com) has developed fiber which can bent more than 90 degree with any loss in optical signals.
So all the changes are making fiber more attractive compared to copper. Ethernet copper will stay there for while but as speed of Ethernet increases, copper will slowly be replaced by Fiber.