Chapter 9, Dual Optical S-4.1Module

Dual Optical S-4.1 Module

9.1 Functional Description of Module

The S4.1-2-LC module contains two optical STM-4 interfaces that meets the S-4.1 specification in ITU-T G.957. The physical connector is an LC connector.

The module supports TDM traffic only.

9.2 Power Consumption

The power consumption of the S4.1-2-LC module is 9,5 W.

9.3 External Interface

The interface ia an optical STM-4 short haul interface, according to clause 5 ITU-T G.957. The definitions of optical parameters and reference points S and R refer to ITU-T G.957. Reference point S refers to the transmit direction and R refers to the receive direction of the fiber. The following descriptions refer to both single mode fiber and multimode fiber. Bidirectional transmission on a single fiber is possible using an external 3dB directional coupler with the S4.1-2-LC module.

9.4 Connector Type

The physical connector is a LC connector.

Figure 9-1 Dual Optical S-4.1 Module, S4.1-2-LC.

9.5 Compliance

Table 9-1 Optical Interface Compliance
Standard	Comment
ITU-T G.652	Single Mode fiber specification 10/125
ITU-T G.651	Multimode fiber specification 50/125 痠
IEC 793-2	Multimode fiber specification 62.5/125 痠
ITU-T G.707	Optical line signal
ITU-T G.783	RX pull-in and hold range
ITU-T G.813	Optical output jitter
ITU-T G.825	Optical input jitter
ITU-T G.957	Optical spectrum, Optical output power, Optical eye diagram, Optical extinction ratio.

9.6 Optical Power Budget S4.1-2-LC Two-Fiber

Table 9-2 Optical Power Budget STM-4 S4.1 SH and LH
Parameter	Short-Haul
Types of fiber:	ITU-T Rec. G.652 SM	10/125	痠
	ITU-T Rec. G.651 MM	50/125
	IEC 739-2 MM	62.5/125
Modulation rate on optical line		622 080	kbps
Wavelength range		1274 - 1356	nm
Transmitter at reference point S
Source type		MLM
Spectral characteristics (max. RMS width)		2.5	nm
Mean launched power (max.)		-8	dBm
Mean launched power (min.)		-15	dBm
Min. extinction ratio		8.2	dB
Optical path between S and R
Attenuation range		0 - 12	dB
Max. tolerable dispersion		200	ps/nm (SM fiber)
Min. optical return loss		NA
Max. discrete reflectance between S and R		NA
Receiver at reference point R
Min. sensitivity (BER < 1 in 1010)		-28	dBm
Min. overload		-8	dBm
Max. optical path penalty		1	dB
Max. reflectance at R		NA

9.7 Optical Power Budget S4.1-2-LC, Single-Fiber Transmission

Bidirectional transmission on a single fiber is possible using an external 3dB directional coupler with the S4.1-2-LC module.

STM-4 S4.1 single fiber has the same specification on the S and R interfaces as the two fiber SH version.

Cisco recommends using mode-conducting cord for offset launch when the quality of multimode fiber is unknown.

Table 9-3 Directional Coupler Properties
Directional Coupler Properties	Short-Haul
Directivity	>40	dB
Maximum insertion loss in coupler	4	dB

Table 9-4 Optical Power Budget Single Fiber Parameters
Parameter	Value
Type of fiber: ITU-T Rec. G.652	10/125	痠
Modulation rate on optical line	622 080	kbps
Wavelength range	1274 - 1356	nm
Transmitter at reference point C
Source type	MLM
Spectral characteristics (max. RMS width)	2.5	nm
Mean launched power (max.)	-11	dBm
Mean launched power (min.)	-19	dBm
Min. extinction ratio	8.2	dB
Optical path between C and remote C
Attenuation range	0 - 4	dB
Max. tolerable dispersion	260	ps/nm
Min. optical return loss of cable plant at C	30	dB
Max. discrete reflectance between C points	-36	dB
Receiver at reference point C
Min. sensitivity (BER < 1 in 1010)	-24	dBm
Min. overload	-5	dBm
Max. optical path penalty	1	dB

Note The STM-4 S4.1 power monitoring of mean Rx power is measured on the R interface.

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