Intra-session network coding has been shown to offer significant gains in terms of achievable throughput and delay in settings where one source multicasts data to several clients. In this paper, we consider a more gen...
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Intra-session network coding has been shown to offer significant gains in terms of achievable throughput and delay in settings where one source multicasts data to several clients. In this paper, we consider a more general scenario where multiple sources transmit data to sets of clients over a wireline overlay network. We propose a novel framework for efficient rate allocation in networks where intermediate network nodes have the opportunity to combine packets from different sources using randomized network coding. We formulate the problem as the minimization of the average decoding delay in the client population and solve it with a gradient-based stochastic algorithm. Our optimized inter-session network coding solution is evaluated in different network topologies and is compared with basic intra-session network coding solutions. Our results show the benefits of proper coding decisions and effective rate allocation for lowering the decoding delay when the network is used by concurrent multicast sessions.
In all of the works related to linear network coding (LNC), researchers use the Galois field (GF) operation property to generate the coding matrix elements. The elements of the coding matrix produced from the coeffici...
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In all of the works related to linear network coding (LNC), researchers use the Galois field (GF) operation property to generate the coding matrix elements. The elements of the coding matrix produced from the coefficients are randomly generated and selected from the GF(q). In this paper, we present an analytical analysis on the effect of using the binary field (OR operation) property to generate the coding matrix elements in LNC instead of using the customary GF. The LNC with binary OR operation (LNC_OR) is simulated under various multihop wireless network conditions of coefficients and coding router for three different network topologies. Each of the three network topologies has different coefficients since different network coding router is used. Performances of the LNC with the different probability of the coefficients of coding matrix base on packet delivery ratio (PDR) are analysed. Simulation results for three different network topologies confirm that LNC_OR reduces the number of lost packets received and improves PDR performance as compared to LNC with GF (LNC_GF) operation property.
In this paper, we consider the broadcast storm problem in dense wireless ad hoc networks where interference among (tensely populated wireless nodes causes significant packet loss. To resolve the problem. we apply rand...
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In this paper, we consider the broadcast storm problem in dense wireless ad hoc networks where interference among (tensely populated wireless nodes causes significant packet loss. To resolve the problem. we apply randomized network coding (RNC) to the networks. RNC Is a completely different approach from existing techniques to resolve the problem. and it reduces the number of Outstanding packets in the network by encoding several packets into a single packet RNC is a kind of linear network coding, and it is suited to wireless ad hoc networks because it can be implemented in a completely distributed manner. We describe a procedure for implementing the wireless ad hoc broadcasting with RNC. Further. with several simulation scenarios. we provide some insights on the relationship between the system parameters and performance and find that there is the optimal length of coding vectors for RNC in terms of packet loss probability. We also show a guideline tor the parameter setting to resolve the broadcast storm problem successfully.
This paper introduces a redundancy adaptation algorithm based on an on-the-fly erasure network coding scheme named Tetrys in the context of real-time video transmission. The algorithm exploits the relationship between...
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This paper introduces a redundancy adaptation algorithm based on an on-the-fly erasure network coding scheme named Tetrys in the context of real-time video transmission. The algorithm exploits the relationship between the redundancy ratio used by Tetrys and the gain or loss in encoding bit rate from changing a video quality parameter called the Quantization Parameter (QP). Our evaluations show that with equal or less bandwidth occupation, the video protected by Tetrys with redundancy adaptation algorithm obtains a PSNR gain up to or more than 4 dB compared to the video without Tetrys protection. We demonstrate that the Tetrys redundancy adaptation algorithm performs well with the variations of both loss pattern and delay induced by the networks. We also show that Tetrys with the redundancy adaptation algorithm outperforms traditional block-based FEC codes with and without redundancy adaptation. (c) 2014 Elsevier B.V. All rights reserved.
A novel optical orthogonal frequency division multiplexing (OFDM) network coding scheme is proposed over passive optical network (PON) system. The proposed scheme for all-optical virtual private network (VPN) does not...
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A novel optical orthogonal frequency division multiplexing (OFDM) network coding scheme is proposed over passive optical network (PON) system. The proposed scheme for all-optical virtual private network (VPN) does not only improve transmission efficiency, but also realize full-duplex communication mode in a single fiber. Compared with the traditional all-optical VPN architectures, the all-optical OFDM network coding scheme can support higher speed, more flexible bandwidth allocation, and higher spectrum efficiency. In order to reduce the difficulty of alignment for encoding operation between inter-communication traffic, the width of OFDM subcarrier pulse is stretched in our proposed scheme. The feasibility of all-optical OFDM network coding scheme for VPN is verified, and the relevant simulation results show that the full-duplex inter-communication traffic stream can be transmitted successfully. Furthermore, the tolerance of misalignment existing in inter-ONUs traffic is investigated and analyzed for all-optical encoding operation, and the difficulty of pulse alignment is proved to be lower. (C) 2013 Elsevier Inc. All rights reserved.
作者：
Kim, MinJiMedard, MurielBarros, JoaoMIT
RLE Cambridge MA 02139 USA MIT
EECS Cambridge MA 02139 USA MIT
Lincoln Lab Opt Commun Grp Cambridge MA 02139 USA MIT
Lincoln Lab Adv Networking Grp Cambridge MA 02139 USA Univ Porto
Fac Engn Inst Telecommun P-4100 Oporto Portugal
We propose a secure scheme for wireless network coding, called the algebraic watchdog. By enabling nodes to detect malicious behaviors probabilistically and use overheard messages to police their downstream neighbors ...
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We propose a secure scheme for wireless network coding, called the algebraic watchdog. By enabling nodes to detect malicious behaviors probabilistically and use overheard messages to police their downstream neighbors locally, the algebraic watchdog delivers a secure global self-checking network. Unlike traditional Byzantine detection protocols which are receiver-based, this protocol gives the senders an active role in checking the node downstream. The key idea is inspired by Marti et al.' s watchdog-pathrater, which attempts to detect and mitigate the effects of routing misbehavior. We first focus on a two-hop network. We present a graphical model to understand the inference process nodes execute to police their downstream neighbors;as well as to compute, analyze, and approximate the probabilities of misdetection and false detection. We also present an algebraic analysis of the performance using an hypothesis testing framework that provides exact formulae for probabilities of false detection and misdetection. We then extend the algebraic watchdog to a more general network setting, and propose a protocol in which we can establish trust in coded systems in a distributed manner. We develop a graphical model to detect the presence of an adversarial node downstream within a general multi-hop network. The structure of the graphical model (a trellis) lends itself to well-known algorithms (e.g. the Viterbi algorithm) which can compute the probabilities of misdetection and false detection. We show that as long as the min-cut is not dominated by the adversaries, upstream nodes can monitor downstream neighbors and allow reliable communication with certain probability. Finally, we present simulation results that support our analysis.
Vehicular ad-hoc networks play an important role in providing safety on the road. Vehicles generate and exchange emergency and control messages to avoid dangerous situations. According to IEEE 1609.4 standard, all the...
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Vehicular ad-hoc networks play an important role in providing safety on the road. Vehicles generate and exchange emergency and control messages to avoid dangerous situations. According to IEEE 1609.4 standard, all these messages share the same control channel interval even if the emergency messages are with a highest priority. Besides that, network's characteristics, such as vehicle density and high mobility, would make the diffusion of emergency messages a challenging task. Especially with the absence of acknowledgements and retransmission. network coding could be seen as a solution where a block of data packets could be sent on the same transmission process. Firstly, we analyze the messages' dissemination, and we propose a thoroughly model for success probability according to the emergency messages' generation probabilities. Further, we propose a new network coding access scheme. The emergency messages take the priority in the channel access and it could be retransmitted several times. Thus, the scheme deals with the emergency messages' loss and latency. NS-3 simulations show that our model increases emergency messages' reliability.
Two explicit schemes are designed to illustrate bidirectional controlled teleportation in a fair and practical manner. One is a symmetric scheme for single-qutrit states. The other is an asymmetric scheme for single- ...
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Two explicit schemes are designed to illustrate bidirectional controlled teleportation in a fair and practical manner. One is a symmetric scheme for single-qutrit states. The other is an asymmetric scheme for single- and two-qutrit states. Then, we extend three-dimensional system to high-dimensional system and come up with a universal scheme for arbitrary n(1)- and n(2)-qudit states by using a (2n(1)+ 2n(2)+1)-qudit entangled state as the quantum channel, where n(1) <=( )n(2). The senders and the controller need to perform general Bell basis measurement and Z basis measurement, respectively. According to their measurement results, the receivers can reestablish the initial states simultaneously by performing single-qudit recovery operations which are derived by a general formula. It is worth mentioning that 2n(1) + 1 dit classical communication cost is saved at the controller's broadcast channel with the aid of network coding. Moreover, we consider the effect of two-type high-dimensional decoherence noises: dit-flip noise and d-phase-flip noise.
Cut-set bounds are not, in general, tight for all classes of network communication problems. In this paper, we introduce a new technique for proving converses for the problem of transmission of correlated sources in n...
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Cut-set bounds are not, in general, tight for all classes of network communication problems. In this paper, we introduce a new technique for proving converses for the problem of transmission of correlated sources in networks, which results in bounds that are tighter than the corresponding cut-set bounds. We also define the concept of "uncertainty region" which might be of independent interest. We provide a full characterization of this region for the case of two correlated random variables. The bounding technique works as follows: on one hand, we show that if the communication problem is solvable, the uncertainty of certain random variables in the network with respect to imaginary parties that have partial knowledge of the sources must satisfy some constraints that depend on the network architecture. On the other hand, the same uncertainties have to satisfy constraints that only depend on the joint distribution of the sources. Matching these two leads to restrictions on the statistical joint distribution of the sources in communication problems that are solvable over a given network architecture. Our technique also provides nontrivial outer bounds for communication problems with secrecy constraints.
network coding is one of the important concepts which make wireless sensor and mesh network more efficient than the traditional one without NC technique. It encodes multiple packets into a single packet and transmits ...
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ISBN:
(纸本)9781479966295
network coding is one of the important concepts which make wireless sensor and mesh network more efficient than the traditional one without NC technique. It encodes multiple packets into a single packet and transmits same in a single transmission cycle. COPE is one of the implementation presented by research community for network coding in wireless sensor network. In COPE, incoming packets stored in virtual queues in respective buffer and packets later on fetch in FIFO order for opportunistic coding. The researchers made several attempts to improve the performance of COPE by adopting various buffer management techniques. The COPE can give considerable coding gain in high traffic networks as per its frame work. In this paper, we are proposing conceptual view of Artificial Bee Colony approach (ABC) to increase the efficiency of COPE in Wireless Mesh networks and Sensor networks, Wireless mesh networks are high traffic and Sensor networks are densely deployed and data centric which can more suitable for network coding while transmitting the data packets from sensor to sink node via base station. ABC is a meta-heuristic optimization algorithm based on collective behavior of decentralized and self organizing systems naturally or artificially.
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