In this work, we propose a novel intra-flow network coding solution, which is based on the combination of a low overhead random linear coding (RLC) scheme and UDP, to offer a reliable communication service. In the ini...
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In this work, we propose a novel intra-flow network coding solution, which is based on the combination of a low overhead random linear coding (RLC) scheme and UDP, to offer a reliable communication service. In the initial protocol specification, the required overhead could be rather large and this had an impact over the observed performance. We therefore include an improvement to reduce such overhead, by decreasing the header length. We describe an analytical model that can be used to assess the performance of the proposed scheme. We also use an implementation within the ns-3 framework to assess the correctness of this model and to broaden the analysis, considering different performance indicators and more complex network topologies. In all cases, the proposed solution clearly outperforms a more traditional approach, in which the TCP protocol is used as a means to offer a reliable communication service.
In this letter, we introduce a new technique for deriving the exact decoding delay distribution expressions of random linear coding schemes over a lossy channel. Our approach is mainly based on two transformations: on...
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In this letter, we introduce a new technique for deriving the exact decoding delay distribution expressions of random linear coding schemes over a lossy channel. Our approach is mainly based on two transformations: on the one hand, from an overall perspective, the correspondence between the calculation of the exact decoding delay distribution over a perfect channel and the counting problem for some special matrices can be established. On the other hand, the relationship between some cardinalities of the special matrices and the typical basis of polynomials can be obtained. Last, the decoding delay distribution issues can be solved by employing the polynomial basis representation method.
We consider the problem of transmitting a collection of packets from a source node to a destination node across a relay network. We analyze a simple random network coding scheme where each node transmits a random line...
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We consider the problem of transmitting a collection of packets from a source node to a destination node across a relay network. We analyze a simple random network coding scheme where each node transmits a randomlinear combination of packets each time it has an opportunity to transmit. The main result of this paper is an upper bound on the expected time to transmit a generation of packets across the network. We show that the expected time is bounded by the generation size divided by the capacity of the minimum cut separating the source from the destination, plus a term that grows as the square root of the generation size. We then use this bound to provide a queueing analysis of a strategy that dynamically creates generations as packets arrive in a queue at the network's source node. To facilitate our analysis, we model the relay network by a continuous-time Markov chain. Our primary analytical tool is a general method for computing upper bounds on hitting times associated with continuous-time Markov chains. We believe that this approach also provides a method for analyzing transmission times associated with more general network topologies.
In this letter we derive an exact formulation for the performance of random linear coding (RLC) when applied over multiple wireless links. We combine this technique with UDP so as to offer a reliable communication ser...
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In this letter we derive an exact formulation for the performance of random linear coding (RLC) when applied over multiple wireless links. We combine this technique with UDP so as to offer a reliable communication service. We extend a previous result, which only considered one single link, to embrace both multiple sources as well as varying quality of wireless links. We establish the number of excess packets that are required to successfully accomplish the communication and, based on the Bianchi model, we calculate the achieved throughput. We also propose a context-aware probabilistic transmission scheme that leads to a relevant performance gain. We use a thorough simulation-based study over the ns-3 framework to assess the validity of the proposed model and to broaden the corresponding analysis.
We propose an enhanced version of an intra-flow Network coding protocol, which was conceived to offer a reliable communication service, by means of the combination a random linear coding (RLC) scheme with the UDP prot...
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ISBN:
(纸本)9783319269252;9783319269245
We propose an enhanced version of an intra-flow Network coding protocol, which was conceived to offer a reliable communication service, by means of the combination a random linear coding (RLC) scheme with the UDP protocol. We reduce the overhead that was originally required in the protocol header and we assess, through an extensive campaign carried out over the ns-3 framework, the performance gain that is brought by this enhancement, comparing it to the TCP protocol, as the mainstream transport-level solution to offer a reliable service. We study the impact of the various configuration parameters of the solution. Afterwards, we challenge the proposed scheme over random topologies (Wireless Mesh Networks or WMNs). The results show a remarkable gain (approximately 20 times higher) of the performance over an ideal channel, thanks to the aforementioned overhead reduction.
In this work we focus on the application of an intra-flow linearrandomcoding scheme over wireless mesh networks. We propose a cross-layer technique to balance the load between relaying nodes, considering the quality...
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ISBN:
(纸本)9781467367820
In this work we focus on the application of an intra-flow linearrandomcoding scheme over wireless mesh networks. We propose a cross-layer technique to balance the load between relaying nodes, considering the quality of the wireless links. We assess the performance of our proposal by means of an extensive simulation campaign carried out over the ns-3 platform, exploiting a channel model based on a Hidden Markov Process, which accurately mimics the bursty behavior that is observed over real indoor channels. The results show the benefits of the proposed cross-layer technique. In addition, we also discuss the trade-off (between accuracy and overhead) that needs to he considered when obtaining the information that such scheme rely on. Our simulations yield a 10% performance gain when exploiting the link quality information, as it is already obtained by various routing protocols.
randomlinear Network coding (RLNC) is a technique that provides several benefits. For instance, when applied over wireless mesh networks, it can be exploited to ease routing solutions as well as to increase the robus...
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ISBN:
(纸本)9781479966646
randomlinear Network coding (RLNC) is a technique that provides several benefits. For instance, when applied over wireless mesh networks, it can be exploited to ease routing solutions as well as to increase the robustness against packet losses. Nevertheless, the complexity of the decoding process and the required overhead might jeopardize its performance. There is a trade-off when deciding the field and block sizes;larger values decrease the probability of transmitting linearly dependent packets, but they also increase both the required overhead and the decoding complexity. In order to overcome these limitations, we propose a sliding window enhancement;a fixed number of packets (fewer than the block size) is combined within every transmission, and the decoding process can therefore take advantage of the algebra with sparse matrices. The paper presents an analytical model, which is first validated and later broaden by means of an extensive simulation campaign carried out over the ns-3 simulator.
randomlinear Network coding (RLNC) is a technique that provides several benefits. For instance, when applied over wireless mesh networks, it can be exploited to ease routing solutions as well as to increase the robus...
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ISBN:
(纸本)9781479966653
randomlinear Network coding (RLNC) is a technique that provides several benefits. For instance, when applied over wireless mesh networks, it can be exploited to ease routing solutions as well as to increase the robustness against packet losses. Nevertheless, the complexity of the decoding process and the required overhead might jeopardize its performance. There is a trade-off when deciding the field and block sizes;larger values decrease the probability of transmitting linearly dependent packets, but they also increase both the required overhead and the decoding complexity. In order to overcome these limitations, we propose a sliding window enhancement;a fixed number of packets (fewer than the block size) is combined within every transmission, and the decoding process can therefore take advantage of the algebra with sparse matrices. The paper presents an analytical model, which is first validated and later broaden by means of an extensive simulation campaign carried out over the ns-3 simulator.
It goes without saying that TCP is the de-facto transport protocol to ensure reliable communications (for instance, in file transfers). On the other hand, and despite the growing relevance of wireless networks, the be...
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ISBN:
(纸本)9781479942763
It goes without saying that TCP is the de-facto transport protocol to ensure reliable communications (for instance, in file transfers). On the other hand, and despite the growing relevance of wireless networks, the behavior of TCP over such technologies is well-known to present clear limitations. Several approaches have been made so as to overcome these problems. In this work we propose a different approach to ensure reliable transmissions over wireless links, based on an random linear coding (RLC) scheme, operating together with UDP. We provide a model of the expected performance of the new scheme. Furthermore, based on an extensive simulation campaign over the ns-3 simulation framework, we assess the validity of this model and we compare its performance with that exhibited by the legacy TCP. The results show that, in particular for lossy links, the proposed scheme clearly outperforms TCP.
We consider a transmitter that encodes data packets using network coding and broadcasts coded packets. A receiver employing network decoding recovers the data packets if a sufficient number of error-free coded packets...
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We consider a transmitter that encodes data packets using network coding and broadcasts coded packets. A receiver employing network decoding recovers the data packets if a sufficient number of error-free coded packets are gathered. The receiver does not abandon its efforts to recover the data packets if network decoding is unsuccessful;instead, it employs syndrome decoding (SD) in an effort to repair erroneous received coded packets, and then reattempts network decoding. Most decoding techniques, including SD, assume that errors are independently and identically distributed within received coded packets. Motivated by the guessing random additive noise decoding (GRAND) framework, we propose transversal GRAND (T-GRAND): an algorithm that exploits statistical dependence in the occurrence of errors, complements network decoding and recovers all data packets with a higher probability than SD. T-GRAND examines error vectors in order of their likelihood of occurring and altering the transmitted packets. Calculation and sorting of the likelihood values of all error vectors is a simple but computationally expensive process. To reduce the complexity of T-GRAND, we take advantage of the properties of the likelihood function and develop an efficient method, which identifies the most likely error vectors without computing and ordering all likelihood values.
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