Loss calculation example for a multimode link

Figure 1 shows a link example consisting of:

Jumper Cable 1 (IBM® duplex-to-duplex, multimode, 13 meters).
Jumper Cable 2 (IBM duplex-to-duplex, multimode, 77 meters). (Combined jumper cable length = 90 meters or 0.09 km).
1.5 km of 50-μm trunk cable (bandwidth = 800 MHz∙km).
One 62.5-μm-to-50.0-μm physical-contact connection (in each fiber).
One 50.0-μm-to-62.5-μm physical-contact connection (in each fiber).
Six 50-μm mechanical splices (in each fiber).
Trunk cable connectors are ST (physical contact).

Note: The example of a completed Calculated Link Loss Work Sheet (Table 1) uses Table 1, which lists typical values for currently used components. Use Table 1 only if the manufacturer's specifications are not available.

Table 1. Example of a Completed Calculated Link Loss Work Sheet for a multimode link.
A. Calculating the multimode component mean loss
Connection loss multiplied by the number of connections in the link:

__62.5___- μm-to-__50.0__- μm connection:	__2.10__ dB	x	___1___	=	__2.10__ dB
__50.0___- μm-to-__62.5__- μm connection:	___0____ dB	x	___1____	=	___0____ dB
________- μm-to- _______- μm connection:	________ dB	x	_______	=	________ dB
Splice loss multiplied by total number of splices in the link:	__0.15__ dB	x	___6____	=	__0.90__ dB
Jumper cable loss multiplied by the combined length of the jumper cables:	__1.75__ dB/km	x	__0.09__ km	=	__0.16__ dB
Trunk loss per kilometer multiplied by the total trunk length (in km):	__0.90__ dB/km	x	__1.5___ km	=	__1.35__ dB
					(+) __________
			Total Component Mean Loss		__4.51__ dB
B. Calculating the multimode component variance loss
Connection variance multiplied by the number of connections in the link:

__62.5__- μm-to-__50.0__- μm	__0.12__ dB²	x	____1___	=	__0.12__ dB²
__50.0__- μm-to-__62.5__- μm connection:	__0.01__ dB²	x	____1___	=	__0.01__ dB²
_______- μm-to-________- μm connection:	________ dB²	x	________	=	________ dB²
Splice variance multiplied by total number of splices in the link:	__0.01__ dB²	x	____6___	=	__0.06__ dB²
					(+) __________
			Total Component Variance Loss		__0.19__ dB²
C. Calculating the total multimode link loss
Total component mean loss:				=	__4.51__ dB

Square root of total component variance loss multiplied by 3:		=	__0.44__ dB x 3	=	__1.32__ dB

High order mode loss:				=	___1.5__ dB
50.0-μm trunk = 1.5 dB
62.5-μm trunk = 1.0 dB					(+) __________

			Calculated link loss		__7.3___ dB