It is a great challenge to transmit data in vehicular networks, where the link among nodes is very shaky because of the rapid movement of vehicles. In this paper, we propose a network coding with Crowdsourcing-based T...
详细信息
It is a great challenge to transmit data in vehicular networks, where the link among nodes is very shaky because of the rapid movement of vehicles. In this paper, we propose a network coding with Crowdsourcing-based Trajectory Estimation (NC/CTE) method to transmit data in vehicular networks. Key points are designated beforehand in movement area. Every node estimates which of Key points the other nodes in the discovered area close to at the different times. The estimation is completed by every node in crowdsourcing method based on the pre-trajectory of GPS navigation. network coding, recoding and reverse forwarding are used for data transmission according to the result of trajectory estimation. Simulation results show that NC/CTE is able to cut down 1/2 overhead messages of TBNC when mobile nodes have shared their GPS trajectories. It improves the reliability and scalability of vehicular networks. (C) 2016 Elsevier Ltd. All rights reserved.
Content Centric networking (CCN) is a new network architecture around content dissemination and retrieval. Its request-response and in-network caching mechanisms can significantly improve the network performance in re...
详细信息
Content Centric networking (CCN) is a new network architecture around content dissemination and retrieval. Its request-response and in-network caching mechanisms can significantly improve the network performance in reducing the transmission delay. However, the in-network caching may prevent the network coding technique from being applied into CCN because cached coded blocks may not be linearly independent to each other such that they cannot be used for responding the future requests. In this paper, we propose a novel request-specified network coding (RSNC) scheme for efficiently encoding and delivering chunks of content. In this scheme, a new Interest coding and forwarding strategy is proposed for specifying network coding requirements and getting linearly independent coded blocks simultaneously from multiple nodes. Our simulation results show that the proposed scheme achieves better performance than conventional CCN in terms of average download time, cache hit ratio, and transmission amount. (C) 2016 Elsevier Ltd. All rights reserved.
network coding is an emerging technique known to improve the network performance in many aspects. In Vehicular Ad-hoc networks (VANET), the bandwidth is considered to be one of the most important network resources. In...
详细信息
network coding is an emerging technique known to improve the network performance in many aspects. In Vehicular Ad-hoc networks (VANET), the bandwidth is considered to be one of the most important network resources. In this paper, we propose a network coding technique to improve the bandwidth utilization for non-safety applications in VANET. In a scenario where there are two sources broadcasting the data into the same area at the same time, the relay will use the network coding technique to decrease the number of rebroadcasting events and the consumption of the bandwidth, However, a fundamental problem for the relay when it receives a packet, is whether to wait for a coding opportunity and save the bandwidth or send the packet directly and reduce the delay. In order to address such tradeoff, we introduce two versions of our protocol, namely buffer size control scheme (BSCS) and time control scheme (TCS);by both versions we aim to control the delay that is experienced by the packet at each hop, while achieving better bandwidth utilization. Up to 38 % improvement in the bandwidth utilization has been recorded, and both schemes have shown a considerable amount of control on the imposed delay.
Link breakage is one of the critical problems that limit the performance of multicast routing in wireless networks. To ease the problem, we apply network coding to the routing operation. In our proposal, data packets ...
详细信息
Link breakage is one of the critical problems that limit the performance of multicast routing in wireless networks. To ease the problem, we apply network coding to the routing operation. In our proposal, data packets are encoded by a random coding scheme. By performing a re-encoding process, the coding scheme is able to keep conveying the data in the network even though link breakage occurs (without the need of waiting for retransmission). To route encoded packets in the network, a disjoint-path tree is used, which is the routing structure constructed by combining a number of multicast trees without the overlapping links among them. Simulation results show that our proposal can effectively ease the impact of link breakage, achieving better packet delivery ratio and higher multicast capacity under different scenarios.
In this paper, we study the problem of distributing a real-time video sequence to a group of partially connected cooperative wireless devices using instantly decodable network coding (IDNC). In such a scenario, the co...
详细信息
In this paper, we study the problem of distributing a real-time video sequence to a group of partially connected cooperative wireless devices using instantly decodable network coding (IDNC). In such a scenario, the coding conflicts occur to service multiple devices with an immediately decodable packet, and the transmission conflicts occur from simultaneous transmissions of multiple devices. To avoid these conflicts, we introduce a novel IDNC graph that represents all feasible coding and transmission conflict-free decisions in one unified framework. Moreover, a real-time video sequence has a hard deadline and unequal importance of video packets. Using these video characteristics and the new IDNC graph, we formulate the problem of minimizing the mean video distortion before the deadline as a finite horizon Markov decision process (MDP) problem. However, the backward induction algorithm that finds the optimal policy of the MDP formulation has high modeling and computational complexities. To reduce these complexities, we further design a two-stage maximal independent set selection algorithm, which can efficiently reduce the mean video distortion before the deadline. Simulation results over a real video sequence show that our proposed IDNC algorithms improve the received video quality compared with the existing IDNC algorithms.
In our recent study, we introduced the PlayNCool protocol that increases the throughput of the wireless networks by enabling a helper node to strengthen the communication link between two neighboring nodes and using r...
详细信息
In our recent study, we introduced the PlayNCool protocol that increases the throughput of the wireless networks by enabling a helper node to strengthen the communication link between two neighboring nodes and using random linear network coding. This paper focuses on design and implementation advantages of the PlayNCool protocol in a real environment of wireless mesh networks. We provide a detailed protocol to implement PlayNCool that is independent from the other protocols in the current computer network stack. PlayNCool performance is evaluated using NS-3 simulations and real-life measurements using Aalborg University's Raspberry Pi test-bed. Our results show that selecting the best policy to activate the helper node is a key to guarantee the performance of PlayNCool protocol. We also study the effect of neighbor nodes in the performance of PlayNCool. Using a helper in presence of active neighbors is useful even if the channel from helper to destination is not better than the channel between sender and destination. PlayNCool increases the gain of end-to-end communication by two-fold or more while maintaining compatibility to standard wireless ad-hoc routing protocols. (C) 2016 Elsevier B.V. All rights reserved.
The paper proposes a resource efficient solution for network coding (NC) based congestion control consisting in identification around the congested links of multiple butterfly or other low complexity NC-capable topolo...
详细信息
The paper proposes a resource efficient solution for network coding (NC) based congestion control consisting in identification around the congested links of multiple butterfly or other low complexity NC-capable topologies by using the Discrete Lagrange Multiplier optimization algorithm. The identification of the NC-capable topologies is based on the resource management capabilities foreseen for the network entities of the Future Internet. The congestion control issue is tackled by separate encoding of appropriately selected groups of data flows passing through the bottleneck link. By optimal selection of the data flows to be encoded, the additional network resources required by the NC operations can be minimized. The encoding is realized by using an XOR-based algorithm adapted for unequal bit rate data flows, and the experimental performances are reported here. Due to its efficient usage of the network resources and high degree of scalability, the congestion control solution proposed in this paper is suitable for large bit rate transmissions, like video streaming.
network coding has emerged as a powerful technique based on a simple but far-reaching observation that, in communication networks, one can allow intermediate nodes to not only forward but also combine and process the ...
详细信息
network coding has emerged as a powerful technique based on a simple but far-reaching observation that, in communication networks, one can allow intermediate nodes to not only forward but also combine and process the incoming information flows. Today, the field is attracting significant interest from both academia and industry, and we are beginning to see the first practical applications. In this survey paper, we first review the main ideas, concepts, and applications of network coding. We then discuss some of the algorithmic aspects of performing network multicast efficiently with network coding. Lastly, we give an overview of a few quantitative results that compare the performance of network coding with that of traditional routing in certain types of communication networks. (C) 2009 Alcatel-Lucent.
Secure transmission in full-duplex relay networks is considered in this paper. To ensure security, we propose a network coding assisted relaying scheme, where all the messages are encoded by the transmitter and the fu...
详细信息
Secure transmission in full-duplex relay networks is considered in this paper. To ensure security, we propose a network coding assisted relaying scheme, where all the messages are encoded by the transmitter and the full-duplex relay respectively. Specifically, the encoding at the transmitter makes sure that all the coded messages are required to decode a private message. Consequently, security is achieved if the eavesdropper loses one or more coded messages. The encoding at the relay is operated by introducing a public auxiliary message, which changes the eavesdropper's decoding method from combining-before-decoding to combining-after-decoding, and thus decreases the eavesdropper's signal-noise-ratio (SNR) obviously. Intercept probability is used to measure the security, and results show that the proposed scheme can significantly improve the security performance of full-duplex relay networks.
Cooperative communication, which utilizes neighboring nodes to relay the overhearing information, has been employed as an effective technique to deal with the channel fading and to improve the network performances. Ne...
详细信息
Cooperative communication, which utilizes neighboring nodes to relay the overhearing information, has been employed as an effective technique to deal with the channel fading and to improve the network performances. network coding, which combines several packets together for transmission, is very helpful to reduce the redundancy at the network and to increase the overall throughput. Introducing network coding into the cooperative retransmission process enables the relay node to assist other nodes while serving its own traffic simultaneously. To leverage the benefits brought by both of them, an efficient Medium Access Control (MAC) protocol is needed. In this paper, we propose a novel network coding aware cooperative MAC protocol, namely NCAC-MAC, for wireless ad hoc networks. The design objective of NCAC-MAC is to increase the throughput and reduce the delay. Simulation results reveal that NCAC-MAC can improve the network performance under general circumstances comparing with two benchmarks.
暂无评论