APPLICATION NOTE : OPTO-LEAP Commtel OPTO-LEAP ensures availability of optical connectivity between the adjacent two stations (A & C) of an intermediate station (B), in the event of loss of DC power supply voltage to communication equipment or drop in voltage below pre-set voltage level at intermediate station . Thus, in true sense the received optical signal at interm ediate station takes a optical ‘LEAP’ to adjacent station optically bypassi ng the intermediate station as shown in following figure:

NORMAL STATE Station A PDH/S DH NODE

Station B

Station C

OPTO- LEAP

PDH/S DH NODE

PDH/S DH NODE

DC SUPPLY

LEAP (BYPASS) STATE Station A PDH/S DH NODE

Station B OPTO- LEAP

PDH/S DH NODE

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Station C PDH/S DH NODE

Χ

DC SUPPLY

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APPLICATION NOTE : OPTO-LEAP The OPTO-LEAP bypasses the intermediate station, irrespective of whether optical signal is with 1310 nm or 1550 nm wavelength and data rate. At the core of this state of the art OPTO-LEAP, an intelligent optical bypass switch is deployed. OPTO-LEAP in Leap or Bypass state optically interconnects the two end stations, therefore in order to use the OPTO-LEAP, it is necessary to carry out the optical power budget calculation, considering the to tal optical link between end stations e.g. Stations A & C. For example, the optical power budget calcul ation should take into account loss due to optical link between Station A to B and St ation B to C. Using the following formula the optical link budget calculation should be carried out: Optical link loss (O

L)

= (D A-B x F L)+ (D B-C x F L) + (S L x (D A-B + DB-C )/D L) + (4 x C L) + (4 x S L) + FM

Where, DA-B = Distance between Station A & B (in Km) DB-C = Distance between Station B & C (in Km) FL = Optical Fiber Loss (in dB/Km) DL = Drum Length (in Km) SL = Splice Loss (in dB) …Typically 0.38 @ 1310 nm and 0.25 @ 1550 nm CL = Connector insertion Loss (in dB) …. Typically 0.5 dB FM = Future Margin (in dB)….. Typically 3 dB Allowable Optical Link Budget (O B) = (Rx senstivity ) – (Tx

power )

Where,

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APPLICATION NOTE : OPTO-LEAP Rxsenstivity = Optical Receiver Sensitivity (in dBm) of Optical unit..

Value

is different for both operating wavelength

Tx power = Optical Transmit Power (in dBm) of Optical unit … End of Life (EOL) should be considered

In order to ensure the communication betw OB must be greater than O

L

een Station A and Station C, the value of

i.e. OB – O L > 0

Enclosed : Product Brochure

Issue 1 October 1, 2004

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