We investigate the performance of delay constrained data transmission over wireless networks without end-to-end feedback. Forward error-correction coding (FEC) is performed at the bit level to combat channel distortio...
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ISBN:
(纸本)9781479935130
We investigate the performance of delay constrained data transmission over wireless networks without end-to-end feedback. Forward error-correction coding (FEC) is performed at the bit level to combat channel distortions and random linear network coding (RLNC) is performed at the packet level to recover from packet erasures. We focus on the scenario where RLNC re-encoding is performed at intermediate nodes and we assume that any packet that contains bit errors after FEC decoding can be detected and erased. To facilitate explicit characterization of data transmission over network-coded wireless systems, we propose a generic two-layer abstraction of a network that models both bit/symbol-level operations at the lower layer (termed PHY-layer) over several heterogeneous links and packet-level operations at the upper layer (termed NET-layer). Based on this model, we propose a network reduction method to characterize the throughput-reliability function of the end-to-end transmission. Our approach not only reveals an explicit tradeoff between data delivery rate and reliability, but also provides an intuitive visualization of the bottlenecks within the underlying network. We illustrate our approach via a point-to-point link and a relay network and highlight the advantages of this method over capacity-based approaches.
The emergence of networkcoding technology is not too early. This technology emerged in the information field in recent years. It is a data storage technology that combines routing and coding to improve transmission e...
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The emergence of networkcoding technology is not too early. This technology emerged in the information field in recent years. It is a data storage technology that combines routing and coding to improve transmission efficiency by additionally encoding data at intermediate nodes[1]. This kind of new technology is able to enhance data throughput, cut down node energy consumption, and achieve energy balance by utilizing the inherent spatial diversity and data redundancy features of WSN. Routing protocol is an important technology in the design of wireless sensor networks. Aiming at the traditional directed diffusion routing protocol(DD), this paper analyzes the problem that the original protocol costs too much in energy and time, and proposes an efficient and energysaving improved directed diffusion routing protocol NC-DD(networkcoding-DD). This protocol solves the problem of excessive energy consumption when the node works caused by a improper forwarding strategy in the original protocol. Experiments show that the NC-DD protocol model can effectively enhance data throughput and cut down time and energy overhead
The emergence of networkcoding technology is not too early. This technology emerged in the information field in recent years. It is a data storage technology that combines routing and coding to improve transmission e...
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ISBN:
(纸本)9781450377027
The emergence of networkcoding technology is not too early. This technology emerged in the information field in recent years. It is a data storage technology that combines routing and coding to improve transmission efficiency by additionally encoding data at intermediate nodes[1]. This kind of new technology is able to enhance data throughput, cut down node energy consumption, and achieve energy balance by utilizing the inherent spatial diversity and data redundancy features of WSN. Routing protocol is an important technology in the design of wireless sensor networks. Aiming at the traditional directed diffusion routing protocol (DD), this paper analyzes the problem that the original protocol costs too much in energy and time, and proposes an efficient and energy-saving improved directed diffusion routing protocol NC-DD (networkcoding-DD). This protocol solves the problem of excessive energy consumption when the node works caused by a improper forwarding strategy in the original protocol. Experiments show that the NC-DD protocol model can effectively enhance data throughput and cut down time and energy overhead
In this paper a cluster head election problem is studied for a cooperative wireless network. The nodes in the cluster use random linear network coding to enhance the throughput performance in spreading the data for a ...
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ISBN:
(纸本)9781424459353
In this paper a cluster head election problem is studied for a cooperative wireless network. The nodes in the cluster use random linear network coding to enhance the throughput performance in spreading the data for a file download service. Some of the nodes in the cluster will access through their cellular link parts of a file to be exchanged among all the cooperative nodes. In such a wireless environment, networkcoding enhances significantly the throughput performance. A good choice of the nodes acting as information sources for the cluster depends on their position and cellular link throughput and turns to be of utmost importance for the achievement of high performance levels. Therefore, a cluster head election algorithm is needed, which shall be fast in converging to either the optimal or, alternatively, a satisfactory sub-optimal solution. We propose to use the evolutionary theory. Results of our investigations are introduced with reference to a high performing implementation of a genetic algorithm under different network conditions both in static and in mobile environments.
Smart meters operate based on their firmware ruling the hardware. The firmware occasionally needs to be updated to fix bugs and improve the services. Since the smart meter firmware is proprietary, the update file shou...
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Smart meters operate based on their firmware ruling the hardware. The firmware occasionally needs to be updated to fix bugs and improve the services. Since the smart meter firmware is proprietary, the update file should be communicated to the smart meters in a secure way. In addition, the firmware update may target a specific subgroup of the smart meters rather than all of them in which case access control is required. In this paper, we address the problem of updating the smart meter firmware securely in an IEEE 802.11s-based AMI network and develop a secure and reliable multicast-over-broadcast protocol by making use of ciphertext-policy attributebased signcryption (CP-ABSC) to provide not only confidentiality and access control but also message authentication. CP-ABSC is employed to signcrypt both the firmware update file and the firmware update request based on an access tree such that the signcrypted update file and request can be designcrypted by the smart meters possessing the attributes that can satisfy the access tree. The preliminary tests showed that increased size of the request due to signcryption reduces reliability of the protocol. Therefore, we employ random linear network coding along with CP-ABSC in order to increase the reliability and use the bandwidth and processing resources efficiently. We assessed the performance of the proposed protocol under ns-3 network simulator. The simulation results have shown that the protocol can accomplish the process of downloading a firmware update without needing any human intervention while consuming less bandwidth when compared to a baseline that employs unicasting.
Data transmission in delay tolerant networks (DTNs) is a challenging problem due to the lack of continuous network connectivity and nondeterministic mobility of the nodes. Epidemic routing and spray-and-wait methods a...
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ISBN:
(纸本)9781538668092;9781538668085
Data transmission in delay tolerant networks (DTNs) is a challenging problem due to the lack of continuous network connectivity and nondeterministic mobility of the nodes. Epidemic routing and spray-and-wait methods are two popular mechanisms that are proposed for DTNs. In order to reduce the transmission delay in DTNs, some previous works combine intra-flow networkcoding with the routing protocols. In this paper, we propose two routing mechanisms using systematic joint inter-and intra-flow networkcoding for the purpose of data exchange between the nodes. We discuss the reasons why inter-flow networkcoding helps to reduce the delivery delay of the packets, and we also analyze the delays related with only using intra-flow coding, and joint inter- and intra-flow coding methods. We empirically show the benefit of joint coding over just intra-flow coding. Based on our simulation, joint coding can reduce the delay up to 40%, compared to only intra-flow coding.
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