Analysis and Evaluation of a Raptor-Based Content Delivery Protocol and its High-Performance Extensions
Miguel Báguena, Carlos T. Calafate, Juan-Carlos Cano and Pietro Manzoni
Forward Error Correction (FEC) has proved to be a very effective solution in the presence of challenging network environments. Its usage is focused mainly on multicast and broadcast delivery, but its impact on research is much wider. For example, FEC can also be used for unicast content delivery to avoid known TCP issues in wireless network environments. In this paper we propose RCDP, a solution that exploits the error resilience properties of Raptor Codes to offer reliable and bidirectional unicast communication in lossy links. Based on an initial approach, different architectural choices are proposed to seek a tradeoff between complexity and efficiency, and offer suitable instances of the protocol for real systems. Experimental results show that RCDP is a highly efficient solution for environments characterized by high delays and packet losses (e.g. ad-hoc networks), achieving significant performance improvements compared to traditional transport-layer protocols.
Keywords: Application-layer FEC, Raptor codes, wireless networks, design and implementation, high-performance extensions, testbed.