Diversity Coding for Transparent Self-Healing Communication Networks.

We present an error control based approach, called diversity coding, to provide nearly instantaneous self-healing digital communication networks. This is achieved by constructing an error-correcting code across logically independent channels and by treating link failures within the framework of an erasure channel model. The need for rapid, self-healing systems is increasing in importance as the backbone network becomes concentrated into fewer high-capacity links. For example, failure of an FT Series-G 1.7 Gbps link must be rapidly restored in order to minimize the disruption to tens of thousands of customers. The technique is also applicable to premises-based private T1 networks. Diversity coding is more efficient than the existing approaches to self-healing communication networks since it is nearly instantaneous, is transparent to the end-user, minimizes the required extra capacity, and does not need rerouting, resynchronization, or a backward channel. It is applicable to both circuit-switched and packet-switched networks, and to a wide variety of network topologies. Diversity coding can be extended to provide protection from short duration environmental disruptions such as multipath fading in radio networks, polarization dispersion in fiber optic networks, or, in conjunction with the existing error detection schemes, to forward error correction for random and burst errors. The basic technique is very versatile, and has potential applications in many other fields, such as distributed storage.