ATL Telecom OM100 - Manual (Page 12)

ATL USER GUIDE
OM100 Optical Multiplexer
21
3.5.6 Protection Switching
Note: This option is only available on the OM100 1+1 SF SM units.
Two, single fibre, bi-directional optical modules are housed within the OM100 case. Either of
these links can fully support all traffic between the two units. Should the active fibre link fail,
the OM100 will automatically switch over to the other link, provided that a valid signal is
available.
The following table describes the conditions which may cause a ‘switch’ to occur.
The OM100 1+1 SF SM unit Protection Switching options, all default to be enabled.
Description
Turns on/off the 1+1 protection switching.
Switch to another link upon detection of LOS
Switch to another optical link upon detection of high bit error
rate exceeding 1x10E-3
The unit will perform a switch if the error rate on the optical
link within any 15 minute period exceeds 1x10E-7.
The unit will perform a switch if the error rate on the optical
link within any 24 hour period exceeds 1x10E-9.
Field
Enable
Switch on LOS
Switch on BER > 10E-3
Switch On Medium Term
Errors > 10E-7
Switch On Long Term Errors >
10E-9
OM100 Mon 01 Nov 2002 00:41:29
Config > Protection Switching
Urgent Alarm:On Non-Urgent Alarm:Off
Enable [X]
Switch On LOS [X]
Switch On BER > 10E-3 [X]
Switch On Bad Medium Term Errors > 10E-7 [X]
Switch On Bad Long Term Errors > 10E-9 [X]
Press Return to Accept or Escape to Cancel
F1 Help F3 Previous Menu F4 Main Menu
3
20 ATL USER GUIDE
OM100 Optical Multiplexer
3.5.5 Range
The range achieved will depend upon the optical fibre used. The better the quality of fibre,
the further the range achieved. Typical figures given below:
Range = Link budget – Connector losses – Splice losses
Attenuation
Note: In the above figures, the attenuation of both the splices and optical connectors has
been assumed to total 1.0 dB.
Id
Cable A
Cable B
Cable C
Attenuation
0.35 dB/Km
0.40 dB/Km
2.40 dB/Km
Range
65.7 Km
57.5 Km
7.1 Km
Fibre Type
Premium single-mode optical fibre
Standard single-mode optical fibre
Standard Multimode optical fibre