US Patent 10397091 Optical safety and connections discovery

At a first optical node of an optical communications system, during a signal initialization phase, a first optical pattern is received that includes a prefix indicating a beginning of a signal, a first word, and a first working signal for verifying stability of a connection between the first optical node and a second optical node of the optical communications system. A second optical pattern is transmitted that includes the prefix, a second word different from the first word, and the first working signal. A third optical pattern including the prefix, the first word, and a second working signal is received. Based on determining that a duration of the second working signal is greater than a duration of the first working signal plus a predetermined time, the first optical node determines that the second optical node is an adjacent node of the first optical node.