This paper presents a low delay time network coding against the high decode time based on opportunities routing in streaming media wireless mesh networks. There are two parts of variable length network coding (VLNC) i...
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We develop a framework that exploits network coding (NC) and multiple-input/multiple-output (MIMO) techniques, jointly together, to improve throughput of downlink broadcast channels. Specifically, we consider a base s...
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We develop a framework that exploits network coding (NC) and multiple-input/multiple-output (MIMO) techniques, jointly together, to improve throughput of downlink broadcast channels. Specifically, we consider a base station (BS) equipped with multiple transmit antennas that serves multiple mobile stations (MSs) simultaneously by generating multiple signal beams. Given the large number of MSs and the small number of transmit antennas, the BS must decide, at any transmission opportunity, which group of MSs it should transmit packets to, in order to maximize the overall throughput. We propose two algorithms for grouping MSs that take advantage of NC and the orthogonality of user channels to improve the overall throughput. Our results indicate that the proposed techniques increase the achievable throughput significantly, especially in highly lossy environments.
The author presents a commentary on a paper published in 'IEEE Transactions on Vehicular Technology,' which investigated the performance of the outage-optimal two-way opportunistic relaying scheme with analog ...
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The author presents a commentary on a paper published in 'IEEE Transactions on Vehicular Technology,' which investigated the performance of the outage-optimal two-way opportunistic relaying scheme with analog network coding over independent but not identically distributed Nakagami-m fading channels. The author argues that the equivalence of the two relay selection criteria used in the paper cannot be guaranteed even for the high-signal-to-noise ratio (SNR) regime.
Combined with rapid recovery of dedicated mode and high resource utilization of shared mode, a network-coding-based Node Protection Mechanism (NNPM) is designed to protect against single node failure in WDM network. T...
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Combined with rapid recovery of dedicated mode and high resource utilization of shared mode, a network-coding-based Node Protection Mechanism (NNPM) is designed to protect against single node failure in WDM network. The analysis and results show that comprehensive advantages can be obtained between dedicated mode and shared mode. Node protection cycles are firstly constructed via Maximum Public-links Mining Algorithm (MPMA) for each node. These cycles will provide maximum number of public-links, which are common links of different node protection cycles. By encoding operation, the data flows on public-links of different cycles can be merged, so the consumption of protection resources is reduced. By decoding operation on public-links, the original data flows on working paths can be restored rapidly without rerouting and retransmitting the data flows, hence the recovery time is also reduced.
In the practical network coding scenario, the adversary usually has full eavesdropping abilities. Hence, lightweight secure network coding is more suitable than the information-theoretic approach. We propose a novel c...
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In the practical network coding scenario, the adversary usually has full eavesdropping abilities. Hence, lightweight secure network coding is more suitable than the information-theoretic approach. We propose a novel coding scheme against a global eavesdropper in this paper. In our scheme, we utilize r mapping values to randomize original packets instead of r locked coefficients. It means that only one encrypted symbol is required for a packet, which rapidly reduces space overhead and encryption volume. Meanwhile, there is no additional requirement at intermediate nodes. Compared to the existing schemes, our scheme is more efficient in space overhead and encryption volume with appropriate computational complexity.
Wireless technologies are increasingly gaining popularity for many industrial automation applications. State-of-the-art wireless technologies mainly support monitoring and open-loop control applications at the lowest ...
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Wireless technologies are increasingly gaining popularity for many industrial automation applications. State-of-the-art wireless technologies mainly support monitoring and open-loop control applications at the lowest level of the automation pyramid. The use of wireless technologies for closed-loop control applications is still in infancy. This paper proposes a novel wireless solution, termed as ENCLOSE, for closed-loop control applications at the sensor/actuator level of factory automation. At the Physical layer, ENCLOSE adopts IEEE 802.15.1 specifications with an enhanced data rate feature. The medium access control layer of ENCLOSE is based on time-division multiple access and frequency-division duplexing. ENCLOSE is based on an optimized frame structure for achieving low latency while accounting for the peculiarities of closed-loop control. Moreover, ENCLOSE implements two different cooperative multi-user diversity techniques for achieving high reliability. Performance evaluation, based on comprehensive analytical modeling and system-level simulation studies, demonstrates that ENCLOSE provides a practical solution, that fulfils the stringent requirements of closed-loop control applications in factory automation environments.
Decentralized proactive caching and coded delivery is studied in a content delivery network, where each user is equipped with a cache memory, not necessarily of equal capacity. Cache memories are filled in advance dur...
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Decentralized proactive caching and coded delivery is studied in a content delivery network, where each user is equipped with a cache memory, not necessarily of equal capacity. Cache memories are filled in advance during the off-peak traffic period in a decentralized manner, i.e., without the knowledge of the number of active users, their identities, or their particular demands. User demands are revealed during the peak traffic period, and are served simultaneously through an error-free shared link. The goal is to find the minimum delivery rate during the peak traffic period that is sufficient to satisfy all possible demand combinations. A group-based decentralized caching and coded delivery scheme is proposed, and it is shown to improve upon the state of the art in terms of the minimum required delivery rate when there are more users in the system than files. Numerical results indicate that the improvement is more significant as the cache capacities of the users become more skewed. A new lower bound on the delivery rate is also presented, which provides a tighter bound than the classical cut-set bound.
This paper investigates distributed linear constellation precoding (DLCP) for two-way relaying communication systems in conjunction with the techniques of bit-interleaved coded modulation (BICM) and BICM with iterativ...
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This paper investigates distributed linear constellation precoding (DLCP) for two-way relaying communication systems in conjunction with the techniques of bit-interleaved coded modulation (BICM) and BICM with iterative decoding (BICM-ID). First, a decoding strategy for the relay node that is based on quaternary code representation is developed. Then, the union bounds (for the case of BICM) and error-free feedback bounds (for the case of BICM-ID) on the quaternary digit error probability and bit error probability under network coding in the multiple-access (MA) phase are obtained. Based on the obtained bounds, the impact of DLCP on the error performance is analyzed by considering three error types in the MA phase. It is shown that type-3 errors need to be carefully taken into account in the design of a DLCP scheme. By developing a performance metric related to type-3 errors, the design parameter of DLCP is optimized when BICM is used, whereas it is shown that DLCP is not needed when BICM-ID is used. Extensive simulation results are provided to corroborate the analysis and demonstrate the performance superiority of the proposed decoding strategy over the one that directly decodes the exclusive-OR (XOR) code. For the case of BICM, the performance advantage achieved by properly designing DLCP is also illustrated.
Most of current studies on Ad Hoc network use redundant transmission to ensure reliability of data transmission, such as multi-path or retransmission. The size of redundant transmission decides whether multipath trans...
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ISBN:
(纸本)9789881563811
Most of current studies on Ad Hoc network use redundant transmission to ensure reliability of data transmission, such as multi-path or retransmission. The size of redundant transmission decides whether multipath transmission is efficient or not. network coding technology provides a method which can effectively reduce the size of redundant transmission on multi-path traffic. Given Ad Hoc networks' features, we establish a multi-path data transmission model and apply the linear random network coding method to it. Then, we propose a practical network coding scheme, complete code design of the network coding part, and successful implement the network coding/decoding process on qualnet5.0. Several comparative experiments are completed. The simulation results show that the improved protocol has significantly reduced the amount of 40% standard redundancy so as to improve network communication capacity.
Efficient data broadcast is of critical importance for Underwater Acoustic networks (UANs) since it provides essential services for various tasks. Due to the unique features of UANs including the long propagation dela...
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Efficient data broadcast is of critical importance for Underwater Acoustic networks (UANs) since it provides essential services for various tasks. Due to the unique features of UANs including the long propagation delay, low bandwidth and high error probability, efficient data broadcast has been facing great challenges. In this paper, we study the problem of distributing data to a group of underwater sensor nodes in partially connected cooperative network using network coding. In such a scenario, the transmission conflicts occur from simultaneous transmissions of multiple nodes, where the scheduling decision should be made not only on the encoded packets but also on the set of transmitting nodes. We formulate the joint optimization problem over the set of transmitting nodes and the packet combinations with a conflict free graph model, which contains both coding conflict and transmission conflict. We also propose a heuristic solution for this setup by finding the maximum independent set in the conflict free graph. Simulation results show that our coding scheme significantly reduces the number of transmission slots.
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