The following operators can be used to better focus your queries.
( ) , AND, OR, NOT, W/#
? single char wildcard, not at start
* multi char wildcard, not at start
(Cat? OR feline) AND NOT dog?
Cat? W/5 behavior
(Cat? OR feline) AND traits
Cat AND charact*
This guide provides a more detailed description of the syntax that is supported along with examples.
This search box also supports the look-up of an IP.com Digital Signature (also referred to as Fingerprint); enter the 72-, 48-, or 32-character code to retrieve details of the associated file or submission.
Concept Search - What can I type?
For a concept search, you can enter phrases, sentences, or full paragraphs in English. For example, copy and paste the abstract of a patent application or paragraphs from an article.
Concept search eliminates the need for complex Boolean syntax to inform retrieval. Our Semantic Gist engine uses advanced cognitive semantic analysis to extract the meaning of data. This reduces the chances of missing valuable information, that may result from traditional keyword searching.
Optical fibers provide a very secure transmission media in that there is no radiated energy around the cable; thus the cable must be opened to intercept the signal.
English (United States)
This text was extracted from a PDF file.
This is the abbreviated version, containing approximately
88% of the total text.
Page 1 of 1
Laser Shutdown And Bring Up Procedure
Optical fibers provide a very secure transmission media in that there is no
radiated energy around the cable; thus the cable must be opened to intercept the
An illegal interception can be detected in duplex systems using some form of
continuous transmission code, such as one that sends idle characters whenever
it is not sending data characters. The detection is accomplished by sensing that
the receiver has gone to any steady state from full off to full on. Once "steady
state" has been detected, the transmitter is signaled to shut down.
Safety regulations also may require shut down when "steady state" is
detected, as eye damage can occur if someone looks too long at the end of a
fiber being driven by a laser of sufficient power.
The problem then is to bring up the lasers once security has been restored
or, if security is no problem, once the cable has been reconnected.
A method to do this is to wait one time increment after "steady state"
detection before shutting down the transmitter. Then, after a wait of at least nine
time increments, transmit for one time increment and shut down if "steady state"
is still present.
The 10% transmission is safe as long as the time increment used is in the
range of 10 milliseconds or less for low power lasers. For higher power the
interval between transmits would be increased, thus reducing the "on"
By waiting one time increment after "steady state" detection before shutti...