IEEE 802.3 100GBase-SR4
Under 100 Gigabit Ethernet, there are several 100GbE interfaces for optical fiber, one of which is 100GBase-SR4, which can bridge distances of several hundred meters. This is a second-generation 100GbE interface, in which 25 Gbit/s each are transmitted via four parallel optical fibers.
The designation 100GBase indicates that the interface supports a data rate of 100 Gbit/s (100G) and operates in baseband technology (base). The specific characteristics can be seen from the suffix SR4. The letter "S" stands for Short and thus for a wavelength of 850 nm, the "R" identifies the interface type with 64B66B coding, and the number 4 states that the transmission is switched using Coarse Wavelength Division Multiplexing( CWDM) over four CWDM paths of a multimode fiber. As a light source, the SR4 interface uses a VCSEL array in which each VCSEL laser generates one of the four wavelengths. In this transmission, each CWDM path transmits a data rate of 25.78 Gbit/s.
Technically, the 100GBase-SR4 interface is implemented with an optical transceiver. The QSFP module is used as the module. The 100GBase-SR4 interface will be available in 2013.