检索结果-内蒙古大学图书馆

An opportunistic routing in wireless mesh network

INTERNATIONAL JOURNAL OF SENSOR networkS 2017年第2期24卷 75-82页

作者： Han, Li Qian, Huan-yan Anhui Univ Sch Comp Sci & Technol Hefei 230039 Peoples R China Nanjing Univ Sci & Technol Sch Comp Sci & Engn Nanjing 210094 Jiangsu Peoples R China

In this paper, the problem of multi-flow opportunistic routing in lossy wireless mesh network is considered. A heuristic algorithm, named MulSrc, is proposed. Building on backpressure scheduling and intra-flow network coding, MulSrc eliminates coordination between node as well as improves the fairness in rate allocation between different flows. To adjust the sources' upper layer rate to network condition, a TCP-like rate control mechanism is adopted, which makes MulSrc suitable for delay-sensitive but loss-tolerant applications, such as adaptive audio/video streaming. Simulation results demonstrate that MulSrc outperforms both a single-path backpressure routing algorithm that uses jointly optimal routing and flow-control approaches and the classical opportunistic routing algorithm MORE.

关键词： network coding multi flow scheduling opportunistic routing multi-hop

来源：评论

学校读者我要写书评

暂无评论

Rate-Aware network Codes for Video Distortion Reduction in Point-to-Multipoint networks

引用

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2017年第8期66卷 7446-7460页

作者： Karim, Mohammad Shahedul Douik, Ahmed Sorour, Sameh Australian Natl Univ Res Sch Engn Acton ACT 2601 Australia CALTECH Dept Elect Engn Pasadena CA 91125 USA Univ Idaho Dept Elect & Comp Engn Moscow ID 83844 USA

This paper considers a wireless point-to-multipoint network in which a base station needs to broadcast a real-time video sequence to a set of devices with heterogeneous channel capacities. In such a scenario, a packet transmission is successfully received at a given device if the adopted transmission rate is lower than the channel capacity of that device. To reduce the video distortion of all devices before the deadline, this paper employs instantly decodable network coding (IDNC) and formulates the video distortion minimization problem as a Markov decision process. Given that the optimal policy suffers from a high computational complexity, an online maximal clique selection algorithm over a rate-aware IDNC graph is proposed to heuristically select a transmission rate and a packet combination at each transmission. This heuristic reduces the individual video distortions of all devices by incorporating the unequal importance of video packets, the hard deadline, and the various channel capacities into the coding decisions. Furthermore, this heuristic is modified to propose a fairer solution that delivers a good quality video to individual devices regardless of their channel conditions. Simulation results over a real video sequence reveal that the proposed IDNC algorithms improve the received video quality as compared to existing rate-aware IDNC algorithms.

关键词： Heterogeneous channel capacities maximal clique network coding real-time video sequences

来源：评论

学校读者我要写书评

暂无评论

Graph Guessing Games and Non-Shannon Information Inequalities

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2017年第7期63卷 4257-4267页

作者： Baber, Rahil Christofides, Demetres Dang, Anh N. Vaughan, Emil R. Riis, Soren Queen Mary Univ London Sch Elect Engn & Comp Sci London E1 4NS England Univ Cent Lancashire CY-7080 Pyla Cyprus

Guessing games for directed graphs were introduced by Riis for studying multiple unicast network coding problems. In a guessing game, the players toss generalised dice and can see some of the other outcomes depending on the structure of an underlying digraph. They later guess simultaneously the outcome of their own die. Their objective is to find a strategy, which maximizes the probability that they all guess correctly. The performance of the optimal strategy for a graph is measured by the guessing number of the digraph. Christofides and Markstrom studied guessing numbers of undirected graphs and defined a strategy which they conjectured to be optimal. One of the main results of this paper is a disproof of this conjecture. The main tool so far for computing guessing numbers of graphs is information theoretic inequalities. The other main result of this paper is that Shannon's information inequalities, which work particularly well for a wide range of graph classes, are not sufficient for computing the guessing number. Finally, we pose a few more interesting questions some of which we can answer and some which we leave as open problems.

关键词： Guessing games network coding multiple unicast information theory Shannon inequalities

来源：评论

学校读者我要写书评

暂无评论

On Design and Efficient Decoding of Sparse Random Linear network Codes

引用

IEEE ACCESS 2017年 5卷 17031-17044页

作者： Li, Ye Chan, Wai-Yip Blostein, Steven D. Nantong Univ Sch Elect & Informat Nantong 226019 Peoples R China Nantong Res Inst Adv Commun Technol Nantong 226019 Peoples R China Queens Univ Dept Elect & Comp Engn Kingston ON K7L 3N6 Canada

While random linear network coding is known to improve network reliability and throughput, its high costs for delivering coding coefficients and decoding represent an obstacle where nodes have limited power to transmit and decode packets. In this paper, we propose sparse network codes for scenarios where low coding vector weights and low decoding cost are crucial. We consider generation-based network codes where source packets are grouped into overlapping subsets called generations, and coding is performed only on packets within the same generation in order to achieve sparseness and low complexity. A sparse code is proposed that is comprised of a precode and random overlapping generations. The code is shown to be much sparser than existing codes that enjoy similar code overhead. To efficiently decode the proposed code, a novel low-complexity overhead-optimized decoder is proposed where code sparsity is exploited through local processing and multiple rounds of pivoting. Through extensive simulation comparison with existing schemes, we show that short transmissions of the order of 10(2) - 10(3) source packets, a denomination convenient for many applications of interest, can be efficiently decoded by the proposed decoder.

关键词： network coding sparse codes random codes generations code overhead efficient decoding

来源：评论

学校读者我要写书评

暂无评论

Instantaneous recovery route design scheme using multiple coding-aware protection scenarios

引用

TELECOMMUNICATION SYSTEMS 2017年第1期64卷 75-85页

作者： Phong Vu Pham Chatterjee, Bijoy Chand Al Muktadir, Abu Hena Oki, Eiji Univ Electrocommun Dept Commun Engn & Informat 1-5-1 Chofugaoka Chofu Tokyo 1828585 Japan

This paper proposes an instantaneous recovery route design scheme using multiple coding-aware link protection scenarios to achieve higher link cost reduction in the network. In this scheme, two protection scenarios, namely, (i) traffic splitting (TS), and (ii) two sources and a common destination (2SD) are used to integrate multiple sources and a common destination. The proposed scheme consists of two phases. In the first phase, the proposed scheme determines routes for 2SD and TS scenarios of all possible source-destination pairs to minimize the total link cost. In this phase, the network coding is applied to the common path within each scenario, individually. In the second phase, network coding is applied to the common path between two scenarios (or a scenario pair) in order to enhance the resource saving. This phase develops conditions that select the most appropriate combination of scenario pairs, such as TS-TS, 2SD-2SD, and 2SD-TS for network coding, including their proofs. Using these conditions, a heuristic algorithm is introduced in order to select the most appropriate combination of scenario pairs for further enhancing of resource saving. Simulation results show that the proposed scheme outperforms the conventional 1 + 1 protection scheme, the TS scenario, and the 2SD scenario in terms of link cost reduction in the network.

关键词： Instantaneous recovery Traffic splitting network coding

来源：评论

学校读者我要写书评

暂无评论

Sending Perishable Information: coding Improves Delay-Constrained Throughput Even for Single Unicast

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2017年第1期63卷 252-279页

作者： Wang, Chih-Chun Chen, Minghua Purdue Univ Sch Elect & Comp Engn W Lafayette IN 47906 USA Chinese Univ Hong Kong Dept Informat Engn Hong Kong Hong Kong Peoples R China

This paper considers network communications under a hard timeliness constraint, where a source node streams perishable information to a destination node over a directed acyclic graph subject to a hard delay constraint. Transmission along any edge incurs unit delay, and it is required that every information bit generated at the source at the beginning of time t to be received and recovered by the destination at the end of time t + D - 1, where D > 0 is the maximum allowed end-to-end delay. We study the corresponding delay-constrained unicast capacity problem. This paper presents the first example showing that network coding (NC) can achieve strictly higher delay-constrained throughput than routing even for the single unicast setting and the NC gain can be arbitrarily close to 2 in some instances. This is in sharp contrast to the delay-unconstrained (D = infinity) single-unicast case where the classic min-cut/max-flow theorem implies that coding cannot improve throughput over routing. Motivated by the above findings, a series of investigation on the delay-constrained capacity problem is also made, including: 1) an equivalent multiple-unicast representation based on a time-expanded graph approach;2) a new delay-constrained capacity upper bound and its connections to the existing routing-based results [Ying et al. 2011];3) an example showing that the penalty of using random linear NC can be unbounded;and 4) a counter example of the tree-packing Edmonds' theorem in the new delay-constrained setting. Built upon the time-expanded graph approach, we also discuss how our results can be readily extended to cyclic networks. Overall, our results suggest that delay-constrained communication is fundamentally different from the well-understood delay-unconstrained one and call for investigation participation.

关键词： network coding max-flow/min-cut delay-constrained communications single unicast network information theory

来源：评论

学校读者我要写书评

暂无评论

Location-Assisted coding for FSO Communication

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2017年第10期65卷 4360-4370页

作者： Duong Nguyen-Huu Thai Duong Thinh Nguyen Norton Symantec Mountain View CA 94043 USA Microsoft Redmond WA 98052 USA Oregon State Univ Sch Elect Engn & Comp Sci Corvallis OR 97331 USA

Recent years have witnessed an explosive growth in the number of wireless devices. This development has fueled much research in wireless access technologies to efficiently use radio frequency spectrum. On the other hand, recent advances in free space optical (FSO) technologies promise a complementary approach to increase wireless capacity. In this paper, we describe WiFO, a hybrid WiFi and FSO high-speed wireless local area network of femtocells that can provide high bit rates while maintaining seamless mobility. Importantly, we introduce a novel location-assisted coding (LAC) technique, based on which, the number of novel rate allocation algorithms is proposed to increase throughput and reduce interference for multiple users in a dense array of overlapped femtocells. Both theoretical analysis and numerical results show orders of magnitude increase in throughput using LAC over existing schemes for various random topologies.

关键词： network coding optical fiber communication wireless communication multiuser channels

来源：评论

学校读者我要写书评

暂无评论

Analog network-Coded Modulation With Maximum Euclidean Distance: Mapping Criterion and Constellation Design

引用

IEEE ACCESS 2017年 5卷 18271-18286页

作者： Yu, Zhijiang Chen, Wei Guo, Xin Chen, Xiang Sun, Chen Tsinghua Univ Dept Elect Engn Beijing 100084 Peoples R China Tsinghua Univ Tsinghua Natl Lab Informat Sci & Technol Beijing 100084 Peoples R China Sony China Ltd Sony China Res Lab Beijing 100028 Peoples R China

Physical-layer network coding holds the great potential of improving the power efficiency and the spectral efficiency for the two-stage transmission scheme. The first stage is the multiple access stage, where two source nodes (SN1 and SN2) simultaneously transmit to the relay node (RN). The second stage is the Broadcast stage, where the RN broadcasts to the two destination nodes (DN1 and DN2), after a denoising-and-mapping operation. In this paper, we investigate the joint network-coded modulation design of the two stages. A universal modulation framework is built, referred to as analog network-coded modulation strategy, which is more general than the former modulation design mechanism. More explicitly, we propose a joint design criterion to guarantee the forwarding reliability at the RN. The criterion ensures that the neighboring constellation points superposed at the RN are mapped to an identical constellation point for broadcasting if their Euclidean distance (ED) is less than a given threshold. This yields a non-convex polynomial optimization problem by minimizing the average transmission power and constraining the ED among the constellation points. By solving the problem, we propose two joint modulation design algorithms, termed as the Enhanced Semidefinite Relaxation Algorithm and the Fast-Relaxation Algorithm, respectively. The two algorithms can achieve the tradeoff between the communication performance and the computation resources. As for the Fast-Relaxation Algorithm, the theoretical performance boundary is derived in detail. Simulation results demonstrate the effectiveness of both the proposed algorithms by comparing symbol error rate performance with the existing modulation design methods.

关键词： Two-way relaying network coding modulation coding physical layer constellation design optimization methods relaxation methods semidefinite programming Gaussian randomization

来源：评论

学校读者我要写书评

暂无评论

Rate Distortion for Lossy In-network Linear Function Computation and Consensus: Distortion Accumulation and Sequential Reverse Water-Filling

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2017年第8期63卷 5179-5206页

作者： Yang, Yaoqing Grover, Pulkit Kar, Soummya Carnegie Mellon Univ Dept Elect & Comp Engn Pittsburgh PA 15213 USA

We consider the problem of distributed lossy linear function computation in a tree network. We examine two cases: 1) data aggregation (only one sink node computes) and 2) consensus (all nodes compute the same function). By quantifying the accumulation of information loss in distributed computing, we obtain fundamental limits on network computation rate as a function of incremental distortions (and hence incremental loss of information) along the edges of the network. The above characterization, based on quantifying distortion accumulation, offers an improvement over classical cut-set type techniques, which are based on overall distortions instead of incremental distortions. This quantification of information loss qualitatively resembles information dissipation in cascaded channels [2]. Surprisingly, this accumulation effect of distortion happens even at infinite blocklength. Combining this observation with an inequality on the dominance of mean-square quantities over relative-entropy quantities, we obtain outer bounds on the rate distortion function that are tighter than classical cut-set bounds by a difference, which can be arbitrarily large in both data aggregation and consensus. We also obtain inner bounds on the optimal rate using random Gaussian coding, which differ from the outer bounds by O(root D), where D is the overall distortion. The obtained inner and outer bounds can provide insights on rate (bit) allocations for both the data aggregation problem and the consensus problem. We show that for tree networks, the rate allocation results have a mathematical structure similar to classical reverse water-filling for parallel Gaussian sources. Apart from data aggregation and distributed consensus, the distortion accumulation analysis framework is also applicable in large-scale data summarization through histograms and linear sketching, e.g., word counting tasks for document summarization.

关键词： Coded computing distortion accumulation in-network computing network coding

来源：评论

学校读者我要写书评

暂无评论

Recovery of Packet Losses in Wireless Broadcast for Real-Time Applications

引用

IEEE-ACM TRANSACTIONS ON networkING 2017年第2期25卷 676-689页

作者： Le, Anh Tehrani, Arash Saber Dimakis, Alexandros Markopoulou, Athina Univ Calif Irvine Dept Elect Engn & Comp Sci Calif Inst Telecommun & Informat Technol Irvine CA 92697 USA Univ Calif Irvine Ctr Pervas Commun & Comp Irvine CA 92697 USA Shoelace Wireless Irvine CA 92617 USA Univ Southern Calif Dept Elect Engn Los Angeles CA 90089 USA Univ Texas Austin Dept Elect & Comp Engn Austin TX 78701 USA

We consider the scenario of broadcasting for real-time applications, such as multi-player games and video streaming, and loss recovery via instantly decodable network coding. The source has a single time slot or multiple time slots to broadcast (potentially coded) recovery packet(s), and the application does not need to recover all losses. Our goal is to find packet(s) that are instantly decodable and maximize the number of lost packets that the users can recover. First, we show that this problem is equivalent to the unique coverage problem in the general case, and therefore, it is hard to approximate. Then, we consider the practical probabilistic scenario, where users have i.i.d. loss probability and the number of packets is either constant (video streaming), linear (multi-player games), or polynomial in the number of users, and we provide two polynomial-time (in the number of users) algorithms. For the single-slot case, we propose Max Clique, an algorithm that provably finds the optimal coded packet w.h.p. For the case where there is a small constant number of slots, we propose Multi-Slot Max Clique, an algorithm that provably finds a near-optimal solution w.h.p. when the number of packets is sufficiently large. The proposed algorithms are evaluated using both simulation and real network traces from an Android multi-player game. And they are shown to perform near optimally and to significantly outperform the state-of-the-art baselines.

关键词： Broadcast loss recovery instantly decodable network codes real-time applications network coding

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：