Fault-Tolerant Real-Time Streaming with FEC thanks to Capillary Multi-Path Routing

Erasure resilient FEC codes in off-line packetized streaming rely on time diversity. This requires unrestricted buffering time at the receiver. In real-time streaming the playback buffering time must be very short. Path diversity is an orthogonal strategy. However, the large number of long paths increases the number of underlying links and consecutively the overall link failure rate. This may increase the overall requirement in redundant FEC packets for combating the link failures. We introduce the Redundancy Overall Requirement (ROR) metric, a routing coefficient specifying the total number of FEC packets required for compensation of all underlying link failures. We present a capillary routing algorithm for constructing layer by layer steadily diversifying multi-path routing patterns. By measuring the ROR coefficients of a dozen of routing layers on hundreds of network samples, we show that the number of required FEC packets decreases substantially when the path diversity is increased by the capillary routing construction algorithm

Fault-Tolerant Streaming with FEC through Capillary Multi-Path Routing

Abstract – Erasure resilient FEC codes in off-line packetized streaming rely on time diversity, which in its turn relies on unrestricted buffering time at the receiver. In real-time streaming the playback buffering time must be very short. Path diversity is an orthogonal strategy, but its drawback is that large number of long paths increases the number of underlying links and consecutively the overall link failure rate. It may result in increase of the overall requirement in redundant FEC packets combating the link failures. We introduce Redundancy Overall Requirement (ROR), a routing coefficient of the total number of FEC packets required for compensation of all underlying link failures. We present capillary routing algorithm constructing layer by layer steadily diversifying multi-path routing patterns. By measuring ROR coefficients of a dozen of routing layers on hundreds of network samples, we show that the number of required FEC packets decreases substantially when the path diversity is achieved by capillary routing algorithm. I

Reliable Multi-Path Routing Schemes for Real-Time Streaming

In off-line streaming, packet level erasure resilient Forward Error Correction (FEC) codes rely on the unrestricted buffering time at the receiver. In real-time streaming, the extremely short playback buffering time makes FEC inefficient for protecting a single path communication against long link failures. It has been shown that one alternative path added to a single path route makes packet level FEC applicable even when the buffering time is limited. Further path diversity, however, increases the number of underlying links increasing the total link failure rate, requiring from the sender possibly more FEC packets. We introduce a scalar coefficient for rating a multi-path routing topology of any complexity. It is called Redundancy Overall Requirement (ROR) and is proportional to the total number of adaptive FEC packets required for protection of the communication. With the capillary routing algorithm, introduced in this paper we build thousands of multi-path routing patterns. By computing their ROR coefficients, we show that contrary to the expectations the overall requirement in FEC codes is reduced when the further diversity of dual-path routing is achieved by the capillary routing algorithm.Comment: Emin Gabrielyan, "Reliable Multi-Path Routing Schemes for Voice over Packet Networks", ICDT'06, International Conference on Digital Telecommunications, Cote d'Azur, France, 29-31 August 2006, pp. 65-7

Uma abordagem para o transporte de vídeo digital baseada em técnicas proativas de QoS

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Tecnológico. Programa de Pós-Graduação em Engenharia Elétric

An Adaptive Redundancy Technique for Wireless Indoor Multicasting

In this paper we present an adaptive technique that com-bines forward error correction (FEC) with channel state estimation (CSE) and automatic repeat request (ARQ) for packet loss recoveiy in wireless indoor multicast systems. The novel aspect of the technique is its ability to achieve signijicant packet throughput with high data reliabiliv, to avoid feedback acknowledgement (ACK) implosion, as well as to reduce andflexibly to limit delay for real-time applicu-tions. We suggest a set of criteria to measure the multicast performance and simulate a simple two-state indoor chan-nel model. The simulation results show that the proposed technique signijicantly improves the communication qual-ity and channel eficiency, to compare with traditional FEC and ARQ techniques. 1