Coded Path Protection Part 1: Efficient Conversion of Sharing to Coding

Link failures in wide area networks are common and cause significant data losses. Mesh-based protection schemes offer high capacity efficiency but they are slow and require complex signaling. Additionally, real-time reconfigurations of crossconnects threaten their transmission integrity. On the other hand, there are other schemes that are proactive. Proactivity results in higher restoration speed, lower signaling complexity, and higher transmission integrity. This paper introduces a codingbased proactive protection scheme, named Coded Path Protection (CPP). In CPP, a backup stream of the primary data is encoded with other data streams, resulting in capacity savings. In addition to a systematic approach of building valid coding structures, this paper presents an optimal and simple capacity placement and coding group formation algorithm. The algorithm converts the sharing structure of any solution of a Shared Path Protection (SPP) technique into a coding structure with minimum extra capacity. W e conducted quantitative and qualitative comparisons of our technique with the SPP. Simulation results confirm that CPP provides faster link failure recovery than SPP while it incurs marginal extra capacity beyond that of SPP. In this Part 1 of the paper, we describe the theory and an algorithm for converting a given SPP solution into a CPP solution. K eyw ordsNetworks, network fault tolerance, codes, shared path protection, network coding.