2017 Volume 6 Issue 12 Pages 633-638
In multi-carrier optical transmission systems, availability of a transponder decreases in accordance with the increase in the number of optical modules comprising the transponder. In this paper, we clarify promising schemes to improve availability by comprehensively comparing them. We first clarify the condition under which availability problems become apparent by analyzing the basic trend in availability. Then, we compare the improvement in availability and difficulty in transmission system development. As a result, we showed that the Pool scheme, where the small amount of shared backup optical modules are implemented to avoid transponder failure, is promising since it effectively increases availability with a small amount of additional optical modules and has enough feasibility.