In order to improve the scheduling efficiency of IEEE 802.16 mesh mode, exactly theoretical analysis is necessary. In the IEEE 802.16 mesh mode with distributed coordinated scheduling, all nodes are peers and multi-ho...
详细信息
ISBN:
(纸本)9781424437092
In order to improve the scheduling efficiency of IEEE 802.16 mesh mode, exactly theoretical analysis is necessary. In the IEEE 802.16 mesh mode with distributed coordinated scheduling, all nodes are peers and multi-hop communication is allowed. Every node has to compete for transmission opportunities based on scheduling information in the two-hop neighborhood. In this paper, we use probability-based method to analyze the performance of network with different topology, different holdoff time and different node degree. The analysis and numerical results show how the three factors mentioned above affect the network throughput and delay.
Coordinating channel access is a fundamental task of the MAC layer in wireless networks. Whereas most proposed medium access techniques involve a pure contention-based mechanism or a centralized polling scheme, we exp...
详细信息
ISBN:
(纸本)9781479923588
Coordinating channel access is a fundamental task of the MAC layer in wireless networks. Whereas most proposed medium access techniques involve a pure contention-based mechanism or a centralized polling scheme, we explore distributed scheduling-based medium access. Intuitively, a scheduling-based scheme would achieve a higher bandwidth efficiency and a lower collision rate than contention-based mechanisms. We develop the Self-Organized distributed Channel Access (SODCA) scheme, that combines the advantages of both contention and scheduling mechanisms. Distinctively from other proposed solutions, SODCA does not incur any additional overhead and is a distributed, highly efficient, compatible, and a dynamic schedule establishment scheme. Through simulation results based on the OMNeT++ network simulator, we demonstrate the high efficiency of SODCA compared to the IEEE 802.11 DCF contention mechanism in both static and dynamic scenarios. SODCA is proven to achieve a collision-free and fair medium access leading to a 20 % higher network throughput than DCF in a static scenario, and a significantly lower collision rate in a dynamic scenario.
In this paper, we propose the PBDT, a novel secret sharing scheme which outperforms current constructions in the distributed wireless network environment. In our scheme, each participant selects his secret share respe...
详细信息
ISBN:
(纸本)9781424437092
In this paper, we propose the PBDT, a novel secret sharing scheme which outperforms current constructions in the distributed wireless network environment. In our scheme, each participant selects his secret share respectively without negotiating with a central node. One secret share can extract several messages without renewing when new participants are added or old participants are deleted. And its share verification phase allows any participant to verify its authenticity and validity. PBDT proves to be practically efficient and computationally secure to resist collision attack, especially for distributed wireless networks.
In this paper, we investigate distributed relay selection in OFDM-based cooperative wireless networks. A selective Decode-and-Forward relaying strategy is adopted, in which one relay is selected to forward the entire ...
详细信息
ISBN:
(纸本)9781424437092
In this paper, we investigate distributed relay selection in OFDM-based cooperative wireless networks. A selective Decode-and-Forward relaying strategy is adopted, in which one relay is selected to forward the entire OFDM symbol. Theoretical outage performance is analyzed and evaluated first. Then six relay selection schemes based on different selection criteria are given. The outage performance of one of the schemes coincides with the theoretical value and all the schemes need only local CSI and can thus be implemented in a distributed way. Monte Carlo simulations validate our analysis and show that significant performance gain can be obtained compared to that of direct transmission.
Based on the finite automata theory, a thinking of distributed deadlock supervisor is proposed is avoid deadlock in Knowledgeable Manufacturing Systems, which is insensitive to system size and improves the efficiency ...
详细信息
ISBN:
(纸本)9781424421077
Based on the finite automata theory, a thinking of distributed deadlock supervisor is proposed is avoid deadlock in Knowledgeable Manufacturing Systems, which is insensitive to system size and improves the efficiency of automata modeling and operating. The conception of the auto-correlation operation is presented, then tire corresponding distributed deadlock supervisors are constructed, and thus the deadlock free strategy of the knowledgeable manufacturing cell is obtained, which can be used to monitor status of the knowledge manufacturing cell in real-time and guarantees safe running of the system. Finally, a case study is presented to demonstrate tire feasibility and effectiveness of the proposed strategy.
作者:
Wang HuaminWuhan Univ
Int Sch Software Res Ctr Spatial Informat & Digital Engn Wuhan 430072 Peoples R China
Spatial data production and update is a systematic project which is costly and involves significant resources. But traditional spatial data production architecture is difficult to share resources and collaborate among...
详细信息
ISBN:
(纸本)9781424413119
Spatial data production and update is a systematic project which is costly and involves significant resources. But traditional spatial data production architecture is difficult to share resources and collaborate among organizations. So in this paper, a distributed spatial data collaborative production architecture in grid environment is proposed, which make advantage of grid technology to organically integrate existing spatial data production resources into a whole, and achieve the object of distributed spatial data collaborative production. This paper analyzed the collaborative architecture and the virtual organizations firstly, and then studied every core components of the architecture. Ultimately, for validating the architecture presented in this paper, we provide a collaborative production prototype system.
At present, most of WfMSs (workflow management systems) in the market are based on centralized defining in the organization. Further more, they have poor ability to describe the complex process, and have difficulty to...
详细信息
ISBN:
(纸本)9781424421077
At present, most of WfMSs (workflow management systems) in the market are based on centralized defining in the organization. Further more, they have poor ability to describe the complex process, and have difficulty to deal with the business process share between cross-organizations. To support virtual and cross-organizational workflows in distributed environment, WfMSs must realize cross-organizational and distributed management to improve the dependability and extensible etc. To solve these issues, a Web-based lightweight process modeling system has been developed in this paper. This system is based on Java and XML technology, and provides friendly GUI which is easy to be used. The model document can be saved in XML format, so the interoperation between different workflow products becomes easy. This system establishes the base for enacting the WfMSs.
To cope with limited capabilities of mobile devices, task offloading in distributed edge computing (DEC) environments is perceived as a promising solution. However, the mobility of devices makes the task offloading a ...
详细信息
ISBN:
(纸本)9781728191010
To cope with limited capabilities of mobile devices, task offloading in distributed edge computing (DEC) environments is perceived as a promising solution. However, the mobility of devices makes the task offloading a more challenging issue. In this paper, we investigate mobility-awareness for optimal task offloading in DEC environments. To this end, we formulate an optimization problem to minimize the response time of offloaded tasks. Simulation results demonstrate that the mobilitya ware task offloading scheme can reduce the response time by 14% similar to 21% compared with the conventional task offloading schemes without any mobility-awareness.
Domain censorship has escalated quickly over time, as have distributed Denial of Service attacks on the Internet. The Domain Name System (DNS) currently in use has small number of root servers which have full control ...
详细信息
ISBN:
(纸本)9781479923588
Domain censorship has escalated quickly over time, as have distributed Denial of Service attacks on the Internet. The Domain Name System (DNS) currently in use has small number of root servers which have full control of the domains. By controlling these servers or access to these servers, one can censor or impersonate parts of the Internet. We propose an open DNS that uses a Peer-to-Peer (P2P) network to store and distribute the records. Anyone can join the network and use and provide distributed Zone Files (DZFs). DZFs are signed with private keys, allowing for multiple Zone Files for each domain, and giving the end user the choice of which keys, if any, to trust. However building a DNS purely based on a P2P network, incurs some overhead. The response times for queries are in the order of 10 to 20 times greater than when using the current DNS, as such the system provides users with a way to circumvent around censored domains, while still being able to use current DNS, for domains that are not censored, keeping response times low for non censored domains, and acceptable for censored domains.
Efficient scheduling of time slots in a time division multiple access scheme (TDMA) is important for low power wireless sensor networks. Existing algorithms are either centralized with poor scalability, or distributed...
详细信息
ISBN:
(纸本)9781424413119
Efficient scheduling of time slots in a time division multiple access scheme (TDMA) is important for low power wireless sensor networks. Existing algorithms are either centralized with poor scalability, or distributed but with high complexity. In this paper, we explain how TDMA could be more energy efficient by careful slot scheduling in wireless sensor networks. Then we propose a deterministic distributed TDMA scheduling algorithm (DD-TDMA). In DD-TDMA, each sensor node schedules its own TDMA slot based on its neighborhood information, and packet collisions are gracefully avoided during scheduling. The experimental results show that compared to other centralized and distributed scheduling algorithms, DD-TDMA achieves better performance in terms of schedule length, running time and message complexity.
暂无评论