What is L in 10GBase-LR?

In 10GBase-LR, the "L" stands for "Long Range." This designation indicates that the standard is designed for long-distance data transmission, specifically over single-mode fiber optic cables. 10GBase-LR can transmit data up to 10 kilometers (6.2 miles) at a data rate of 10 gigabits per second, making it suitable for applications requiring extended reach in metropolitan or campus networks.