Loss calculation example for a single-mode link

Figure 1 shows a link example consisting of:

Jumper Cable 1 (IBM® duplex-to-duplex, single-mode, 92 meters).
Jumper Cable 2 (IBM duplex-to-duplex, single-mode, 122 meters) (combined jumper cable length = 214 meters or 0.21 km).
19.76 km of 9-μm trunk cable.
Two physical-contact ST connections (in each fiber).
Two mechanical splices (in each fiber).

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.

Example of a single-mode ESCON link. — Figure 1. Example of a single-mode ESCON link

Table 1. Example of a completed calculated link loss work sheet for a single-mode link. This example was completed for an ESCON link.
A. Calculating the single-mode component mean loss

Connection loss multiplied by the number of connections in the link:	__0.35__ dB	x	___2___	=	__0.706__ dB
Splice loss multiplied by total number of splices in the link:	__0.15__ dB	x	___2____	=	__0.30___ dB
Jumper cable loss multiplied by the combined length of the jumper cables:	__0.8___ dB/km	x	__0.21__ km	=	__0.17__ dB
Trunk loss per kilometer multiplied by the total trunk length (in km):	__0.5___ dB/km	x	__19.76__ km	=	__9.88__ dB
					(+) __________
			Total component mean loss		__11.05__ dB

B. Calculating the single-mode component variance loss
Connection variance multiplied by the number of connections in the link:	__0.06__	x	____2___	=	__0.12__ dB²
Splice variance multiplied by total number of splices in the link:	__0.01__ dB²	x	____2___	=	__0.02__ dB²
					(+) __________
			Total component variance loss		__0.14__ dB²

C. Calculating the total single-mode link loss
Total component mean loss:				=	__11.05__ dB

Square root of total component variance loss plus system variance loss (0.04 dB) multiplied by 3:		=	__0.436__ dB x 3	=	__1.31__ dB

Jumper assembly loss plus excess connector loss:				=	0.50 dB
					(+) __________
.			Calculated link loss		__12.86__ dB