Gigabit Ethernet can typically be transmitted up to 275 meters on OM1, 550 meters on OM2, and up to 2 kilometers using advanced techniques on multimode fiber.

Standard Multimode Fiber Distances

• OM1 (62.5 µm core, 200 MHz·km bandwidth): Supports 1 Gbps up to 275 meters. It is mainly used for short-distance LAN applications and lower-speed networks due to its limited bandwidth and LED light source .
• OM2 (50 µm core, 500 MHz·km bandwidth): Extends 1 Gbps transmission up to 550 meters. OM2 is also LED-based and commonly used in enterprise LANs .
• OM3 (50 µm core, 2,000 MHz·km bandwidth, laser-optimized): Supports 1 Gbps over standard distances exceeding 550 meters, and 10 Gbps up to 300 meters. OM3 is widely used in data centers and campus networks .
• OM4 (50 µm core, 4,700 MHz·km bandwidth, laser-optimized): Improves performance over OM3, supporting 10 Gbps up to 550 meters and, with advanced transceivers or WDM, Gigabit Ethernet distances can reach up to 2 km .

Factors Affecting Transmission Distance

1. Modal Dispersion: Multimode fibers carry multiple light modes, which spread out over distance, limiting the maximum reach at higher data rates .
2. Light Source: LED sources have broader spectral widths, reducing distance, while VCSEL lasers provide narrower spectral widths, extending effective transmission .
3. Fiber Quality and Bandwidth: Higher effective modal bandwidth (EMB) fibers like OM4 allow longer distances at the same data rate .
4. Network Components: High-quality connectors, patch panels, and splices reduce signal loss and help maintain longer distances .

Practical Considerations

• For typical LANs and enterprise networks, OM1 or OM2 fibers are sufficient for 1 Gbps over short distances.
• For data centers or high-speed networks, OM3 or OM4 fibers are preferred due to their laser-optimized cores and higher bandwidth, allowing longer distances and future-proofing for 10 Gbps or higher speeds .
• Distance extension techniques like WDM (wavelength-division multiplexing) and advanced SFP transceivers can push Gigabit Ethernet over multimode fiber beyond standard limits, up to 2 km . In summary, the maximum Gigabit Ethernet distance over multimode fiber depends on the fiber type and network setup, ranging from 275 meters on OM1 to potentially 2 kilometers using OM4 with advanced transceivers. Choosing the right fiber type and components is crucial for reliable high-speed transmission.