Reliable streaming protocol for lossy networks

This paper introduces REST, a reliable streaming protocol for lossy networks. REST ensures full reliability while recovering losses as soon as possible thanks to the proactive injection of redundancy packets encoded following an on-the-fly scheme. It dynamically adapts the sending of codes depending on the estimation of the packet error rate with periodic acknowledgments to limit feedback dependency and protocol overhead. Results show that data are smoothly delivered to the receiving application with minimum overhead when errors are uniform. For systems with limited processing capacity, we proposed to use a bounded encoding window to deliver data more uniformly while limiting the decoding matrix size. We study the performance of REST under different network conditions and highlight the underlying tradeoffs behind each system parameter. We show that an optimal acknowledgement frequency can be found to minimize overhead while meeting system requirements in terms of delivery delay and computational power

eCMT-SCTP: Improving Performance of Multipath SCTP with Erasure Coding Over Lossy Links

Performance of transport protocols on lossy links is a well-researched topic, however there are only a few proposals making use of the opportunities of erasure coding within the multipath transport protocol context. In this paper, we investigate performance improvements of multipath CMT-SCTP with the novel integration of the on-the-fly erasure code within congestion control and reliability mechanisms. Our contributions include: integration of transport protocol and erasure codes with regards to congestion control; proposal for a variable retransmission delay parameter (aRTX) adjustment; performance evaluation of CMT-SCTP with erasure coding with simulations. We have implemented the explicit congestion notification (ECN) and erasure coding schemes in NS-2, evaluated and demonstrated results of improvement both for application goodput and decline of spurious retransmission. Our results show that we can achieve from 10% to 80% improvements in goodput under lossy network conditions without a significant penalty and minimal overhead due to the encoding-decoding process

Building self-optimized communication systems based on applicative cross-layer information

This article proposes the Implicit Packet Meta Header(IPMH) as a standard method to compute and represent common QoS properties of the Application Data Units (ADU) of multimedia streams using legacy and proprietary streams’ headers (e.g. Real-time Transport Protocol headers). The use of IPMH by mechanisms located at different layers of the communication architecture will allow implementing fine per-packet selfoptimization of communication services regarding the actual application requirements. A case study showing how IPMH is used by error control mechanisms in the context of wireless networks is presented in order to demonstrate the feasibility and advantages of this approach

The QUIC Fix for Optimal Video Streaming

Within a few years of its introduction, QUIC has gained traction: a significant chunk of traffic is now delivered over QUIC. The networking community is actively engaged in debating the fairness, performance, and applicability of QUIC for various use cases, but these debates are centered around a narrow, common theme: how does the new reliable transport built on top of UDP fare in different scenarios? Support for unreliable delivery in QUIC remains largely unexplored. The option for delivering content unreliably, as in a best-effort model, deserves the QUIC designers' and community's attention. We propose extending QUIC to support unreliable streams and present a simple approach for implementation. We discuss a simple use case of video streaming---an application that dominates the overall Internet traffic---that can leverage the unreliable streams and potentially bring immense benefits to network operators and content providers. To this end, we present a prototype implementation that, by using both the reliable and unreliable streams in QUIC, outperforms both TCP and QUIC in our evaluations.Comment: Published to ACM CoNEXT Workshop on the Evolution, Performance, and Interoperability of QUIC (EPIQ

Network Coding-Assisted Retransmission Scheme for Video- Streaming Services over Wireless Access Networks

Video-streaming services, such as Internet protocol television, promising the delivery of multimedia contents over wireless access networks to clients whenever and wherever, are becoming more and more popular. However, scarce radio resources, lossy characteristics of wireless links and high bandwidth demands pose the never-ending challenges for provisioning of real-time streaming services over wireless networks in a timely and reliable manner. Furthermore, a wireless channel may suffer from interference and multipath fading, which may cause random packet losses. In addition, wireless link layer does not provide a retransmission mechanism for multicast/broadcast traffic. This would significantly impact the clients’ quality of experience of streaming services. Traditional unicast retransmission solutions improve client’s quality, at the bandwidth expense, because every lost packet must be retransmitted separately. This chapter presents and practically evaluates a retransmission scheme for video-streaming services over last mile wireless networks. It is based on network coding techniques that increase the overall performance by means of reducing the number of physical transmissions, in comparison to traditional unicast retransmission approach, resulting in reduced bandwidth consumption. Thus, the Internet service providers can increase the number of clients over the same infrastructure or, alternatively, offer more services to the clients

Cooperative Retransmissions Through Collisions

Interference in wireless networks is one of the key capacity-limiting factors. Recently developed interference-embracing techniques show promising performance on turning collisions into useful transmissions. However, the interference-embracing techniques are hard to apply in practical applications due to their strict requirements. In this paper, we consider utilising the interference-embracing techniques in a common scenario of two interfering sender-receiver pairs. By employing opportunistic listening and analog network coding (ANC), we show that compared to traditional ARQ retransmission, a higher retransmission throughput can be achieved by allowing two interfering senders to cooperatively retransmit selected lost packets at the same time. This simultaneous retransmission is facilitated by a simple handshaking procedure without introducing additional overhead. Simulation results demonstrate the superior performance of the proposed cooperative retransmission.Comment: IEEE ICC 2011, Kyoto, Japan. 5 pages, 5 figures, 2 tables. Analog Network Coding, Retransmission, Access Point, WLAN, interference, collision, capacity, packet los