10 Gigabit Ethernet
Gigabit Ethernet over fiber has been around since 1998 and over copper since 1999. As users contemplate upgrading their network to provide "Gigabit to the desk over copper", they will have to upgrade the backbones from 1Gb/s to 10Gb/s. The IEEE is working on a specification for 10Gb/s Ethernet. Manufacturers are willing to support 10 Gigabit Ethernet over existing multimode fiber, be it 50/125 or 62.5/125 fiber but it may be as little as 26 meters depending on the modal bandwidth of the cable and source used. They are however happy to support it over existing singlemode installations to 10km at 1310nm and 30km at 1550nm.

A number of manufacturers have released a new generation of multimode fibers which have superior modal bandwidth. These tend to be 50/125 and are designed to support 10 Gigabit Ethernet to at least 300 meters. This means that you can install a fiber which supports inexpensive LED sources as well as more expensive laser sources.

For existing multimode fiber there may be an opportunity to implement Wave Division Multiplexing (WDM) using a WDM card to get 10 GBC up to 300 meters. WDM effectively uses 4 sources, at 4 different wavelengths, at 3.125Gb/s each. This solution comes at a cost since you are using 4 sources rather than one.

The final approval of the 10GbE standard 802.3ae 10 Gigabit Ethernet over Fiber will go through formal acceptance in IEEE on July 9.