On Unicast based Recovery for Multicast Content Distribution considering XOR-FEC

Abstract

In this paper, we propose a fail-safe and efficient download completion scheme for reliable multicast to which FEC (Forward Error Correction) is applied with practical constraints on multicast transmission time. Recently, erasure codes based on XOR operation have become major FEC candidates for multicast content file distribution over the Internet or mobile networks in terms of their recovery performance and processing overheads. In particular LT (Luby Transform) codes are effective in a heterogeneous multicast environment because they can achieve higher reliability by expanding the receiving time at each client. However, multicast transmission time can be restricted due to operational reasons considering multicast resource efficiency. In order to assure all the clients of download completion under such conditions, we newly designed a unicast based recovery mechanism considering LT codes characteristics. We confirmed the efficiency of our proposed mechanism by computer simulation.

A Cross Layer Video Transmission Scheme Combining Geographic Routing and Short-Length Luby Transform Codes

“…where is the size of source symbol; the length of encoded symbol overhead is 4, and is obtained from (7). The relationship between the ( ) and size is shown in Figure 3.…”

“…where is the size of source symbol; the length of encoded symbol overhead is 4, and is obtained from (7).…”

“…For achieving higher reliability, several Forward Error Correction (FEC) schemes have been proposed and widely used for recovering data from a packet loss [6, 7]. Erasure codes based on XOR operation have become major FEC candidates for reliable data distribution over the wireless networks in terms of their recovery performance.…”

Estudo sobre a Concatenação Bidimensional de Códigos LT

“…Os códigos LT (Luby Transform), propostos por Michael Luby em 2002 [2], foram a primeira implementação do conceito de fontanas digitais (digital fountains) com tempos de codificação e decodificação viáveis em sistemas que requeiram a formação de um grande número de símbolos codificados n, a partir de k símbolos de entrada. Por serem baseados em operações XOR, estes códigos apresentam altas velocidades de codificação e decodificação, além de oferecerem uma promissora capacidade na correção de erros [3]. Os códigos LT foram originalmente concebidos para canais com apagamento, BEC (Binary Erasure Channel), livres de erros.…”