Error-correcting coding for IM/FSK modulation format for optical labeling of signals

Optical label switching has received much attention recently as a paradigm for IP over WDM networking. It provides quick and efficient forwarding of bursts of IP packets, enabling scaling to terabit per second rates. A combined IM/FSK modulation format for payload/label encoding is a promising technique to implement labeling of optical signals. Although, IM/FSK modulation format presents several advantageous features, the extinction ratio of the IM format is compromised to provide proper detection of the FSK label data. In this paper, we proposed to use forward error-correction (FEC) for the FSK label encoded data. Because, the labels are of a fixed, short length, and low data-rate, FEC codes with small redundancy, yet powerful and simple to implement can be employed. Simulation and analytical results predicts that by using FEC, the extinction ratio for the IM signal can be kept at the value used by conventional IM transmission systems. Moreover, besides error-correction, coding could be extended to cover other functionalities such as identification of labels for data security, among others.