Evaluation of adaptive LDPC AL-FEC codes for content download services

This paper presents a performance analysis of adaptive LDPC AL-FEC codes for content download services over erasure channels. In adaptive LDPC codes, clients inform the content download server of the losses they are experiencing. Using this information, the server makes FEC parity symbols available to the client at an optimum code rate. Results show the performance of adaptive AL-FEC codes for different scenarios as compared to non-adaptive AL-FEC, to optimum LDPC AL-FEC codes and to an almost ideal rateless code. Adaptive LDPC AL-FEC codes achieves download times similar to almost ideal rateless codes with less coding complexity, at the expense of an interaction channel between server and clients¹.