單項選擇題Scrambling of SONET signals is done to ().

A. prevent the leakage of external fiber emissions
B. provide the optical network with the highest level of security possible
C. assure an even distribution of 1's and 0's for extended transmitter life
D. assure an adequate number of transitions for clock recovery at the receiver
E. prevent the receiver from assuming AIS inadvertently when all 0's are received


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1.單項選擇題A Channel ID mismatch occurs when ().

A. fibers are terminated incorrectly on a node
B. the channel number in the received K1 byte is not identical to the channel number transmitted in the K2 byte
C. the channel number in the received C1 byte is not identical to the channel number transmitted in the C2 byte
D. the channel number in the received C2 byte is not identical to the channel number transmitted in the C1 byte
E. the channel number in the received K2 byte is not identical to the channel number transmitted in the K1 byte

3.單項選擇題Which timing mode is most appropriate for an ONS 15454 that has lost its BITS-1 and optical references?()

A.line timing
B.loop timing
C.internal timing
D.through timing
E.external timing

5.單項選擇題A customer has 2 DS1s to add between adjacent nodes in a UPSR ring. What type of circuit should you recommend?()

A. VT circuits
B. STS circuits
C. VT tunnel circuits
D. 1:1 protection circuits
E. 1:N protection circuits

最新試題

What are two important considerations when using 2- or 4-channel 15216 OADMs?() (Choose two.)

題型:多項選擇題

How is a Thin Film filter fabricated?()

題型:單項選擇題

What is the phenomenon called where different wavelengths of light travel at different speeds?()

題型:單項選擇題

In order to avoid misconnections due to a failed node in a Bidirectional Line Switched Ring (BLSR), Alarm Indication Signals (AISs) are sent on every channel normally terminating in that node. What is the name of this process?()

題型:單項選擇題

Which timing mode is appropriate for a SONET NE that is adjacent to a SONET NE using BITS-1 timing source?()

題型:單項選擇題

Click the Exhibit button. Given the following parameters: transmitter output (min): -2 dBm receiver input (min): -28 dBm 15216 Mux and Demux loss: 4.5 dB 16 channels maximum In which sites shown in the exhibit could the 15216 EDFAs be placed to minimize the number of EDFAs needed?()

題型:單項選擇題

Click the Exhibit button. The exhibit shows a 15454/15216 DWDM system and alarm indications. What are two possible sources of trouble shown in the system?() (Choose two.)

題型:多項選擇題

Which device creates an OEO conversion?()

題型:單項選擇題

Given the formula: (Fiber Attenuation * Km) + (Splice Attenuation * # of Splices) + (Connector Attenuation * # of Connectors) + (Optical Fiber or OADM) + Buffer(Fiber aging)) With regard to SONET/SDH optical calculations, what will the given formula provide?()

題型:單項選擇題

Click the Exhibit button. When designing a DWDM system with multiple amplified spans, a pre-amp is needed at Site B to (). (Choose three.)

題型:多項選擇題