HP HSR6800 Router manual 9

pulse that can pass a fiber × the fiber length. The modal bandwidth is a comprehensive index reflecting the optical characteristics of a multimode fiber.

International Telecommunication Union (ITU) defines multimode fiber types in its G series standards. The commonly-used multimode fiber is defined in the ITU G.651 standard. The G.651-compliant fiber transmits light at the wavelength range 800 nm to 900 nm or 1200 nm to 1350 nm.

Table 2 Multimode fiber grades

Fiber mode	Fiber grade	Fiber diameter (μm)	Modal bandwidth at
			850 nm (MHz*km)
	OM1	62.5/125	200
Multimode fiber	OM2	50/125	500
	OM3	50/125	2000

Other factors that influence the transmission distance of multimode fibers include interface type, central wavelength, and fiber grade. For more information, see Table 3.

Table 3 Multimode fiber specifications

Interface type	Central	Fiber grade	Transmission distance
	wavelength (nm)
1000BASE-SX	850	OM1	< 275 m (902.23 ft)
		OM2	< 550 m (1804.46 ft)
		OM1	< 33 m (108.27 ft)
10GBASE-SR	850	OM2	< 82 m (269.03 ft)
		OM3	< 300 m (984.25 ft)
		OM1	< 220 m (721.78 ft)
10GBASE-LRM	1310	OM2	< 220 m (721.78 ft)
		OM3	< 220 m (721.78 ft)

•Single-mode fibers

Single-mode fibers (SMFs) have a small core size, typically 9 μm or 10 μm, and can transmit light in only one mode. Single-mode fibers suffer little intermodal dispersion and are suitable for long-haul communication. Single-mode fibers transmit light at the central wavelength of 1310 nm or 1550 nm.

Telecommunication Industries Alliance (TIA)/Electronic Industries Alliance (EIA) defines that single-mode fibers use yellow outer jackets with the mark "SM".

ITU defines single-mode fiber types in its G series standards. The mostly-commonly used single-mode fibers are defined in ITU G.652 and G.655 standards. Table 4 describes features of the G.652 and G.655-compliant fibers.

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