The wireless sensor network (WSN) is one of the budding exploring areas and fast rising fields in wireless communications. The sensor nodes in the network are generally small-size, low-cost, low-power and multi-functi...The wireless sensor network (WSN) is one of the budding exploring areas and fast rising fields in wireless communications. The sensor nodes in the network are generally small-size, low-cost, low-power and multi-function capabilities. Wireless sensor networks (WSNs) are used for various applications;since numerous sensor nodes are usually deployed on remote and inaccessible places, the employment and preservation should be easy and scalable. Sensor nodes in the field being run out of energy quickly has been an issue and many energy efficient routing protocols have been proposed to solve this problem and preserve the long life of the network. This paper work proposes a hierarchical based node activation routing technique which shows energy efficiency. This technique selects cluster head with highest residual energy in each communication round of transmission to the base station from the cluster heads. Hierarchical based node activation routing technique with different levels of hierarchy simulation results prolongs the lifetime of the network compared to other clustering schemes and communication rounds of simulation increase significantly.展开更多
Pursuing higher data rate with limited spectral resources is a longstanding topic that has triggered the fast growth of modern wireless communication techniques.However,the massive deployment of active nodes to compen...Pursuing higher data rate with limited spectral resources is a longstanding topic that has triggered the fast growth of modern wireless communication techniques.However,the massive deployment of active nodes to compensate for propagation loss necessitates high hardware expenditure,energy consumption,and maintenance cost,as well as complicated network interference issues.Intelligent metasurfaces,composed of a number of subwavelength passive or active meta-atoms,have recently found to be a new paradigm to actively reshape wireless communication environment in a green way,distinct from conventional works that passively adapt to the surrounding.In this review,we offer a unified perspective on how intelligent metasurfaces can facilitate wireless communication in three manners:signal relay,signal transmitter,and signal processor.We start by the basic modeling of wireless channel and the evolution of metasurfaces from passive,active to intelligent metasurfaces.Integrated with various deep learning algorithms,intelligent metasurfaces adapt to cater for the ever-changing environments without human intervention.Then,we overview specific experimental advancements using intelligent metasurfaces.We conclude by identifying key issues in the practical implementations of intelligent metasurfaces,and surveying new directions,such as gain metasurfaces and knowledge migration.展开更多
In an active network, users can insert customized active codes into activenodes, to execute. Thus it needs more resources than those required by conventional networks, andthese resources must be effectively monitored ...In an active network, users can insert customized active codes into activenodes, to execute. Thus it needs more resources than those required by conventional networks, andthese resources must be effectively monitored and managed. Management policies in existing OSs aretoo complicated to apply to simple active packets. In this paper, we present new resourcesmanagement policies that are mainly adoped to manage CPU, storage and transmission bandwidth.Namely, we use SPF algorithm to schedule and process active packets, and import an interval queuemethod to allocate transmission bandwidth, and use feedback mechanism to control congestion . At thesame time, we design some experiments on prototype systems with and without resources managementpolicies respectively. The experiments results show that management policies presented by us caneffectively manage resources in active nodes and can improve the performance of active networks.展开更多
The spray and wait protocol is a classic copy-limited spraying protocol in delay tolerant networks, in which, the binary spray mode can be improved for heterogeneous delay tolerant networks. In this article, a new con...The spray and wait protocol is a classic copy-limited spraying protocol in delay tolerant networks, in which, the binary spray mode can be improved for heterogeneous delay tolerant networks. In this article, a new conception of node activity was defined to weigh the importance of nodes in aspect of message dissemination in the whole network. A new spray and wait protocol with node activity was proposed to improve the performance in heterogeneous delay tolerant networks. A mathematical model used under varieties of the spraying protocols was also proposed to analyze the expected delay of the protocol. Simulations show that the spray token proportion with node activity is optimal and the new protocol is of better performance than other related protocols. Therefore, this protocol has high efficiency and good scalability.展开更多
文摘The wireless sensor network (WSN) is one of the budding exploring areas and fast rising fields in wireless communications. The sensor nodes in the network are generally small-size, low-cost, low-power and multi-function capabilities. Wireless sensor networks (WSNs) are used for various applications;since numerous sensor nodes are usually deployed on remote and inaccessible places, the employment and preservation should be easy and scalable. Sensor nodes in the field being run out of energy quickly has been an issue and many energy efficient routing protocols have been proposed to solve this problem and preserve the long life of the network. This paper work proposes a hierarchical based node activation routing technique which shows energy efficiency. This technique selects cluster head with highest residual energy in each communication round of transmission to the base station from the cluster heads. Hierarchical based node activation routing technique with different levels of hierarchy simulation results prolongs the lifetime of the network compared to other clustering schemes and communication rounds of simulation increase significantly.
基金sponsored by the Key Research and Development Program of the Ministry of Science and Technology under Grant Nos.2022YFA1404704,2022YFA1405200,and 2022YFA1404902the National Natural Science Foundation of China(NNSFC)under Grant Nos.62422514,62471432,62101485 and 61975176+1 种基金the Key Research and Development Program of Zhejiang Province under Grant No.2022C01036the Fundamental Research Funds for the Central Universities.
文摘Pursuing higher data rate with limited spectral resources is a longstanding topic that has triggered the fast growth of modern wireless communication techniques.However,the massive deployment of active nodes to compensate for propagation loss necessitates high hardware expenditure,energy consumption,and maintenance cost,as well as complicated network interference issues.Intelligent metasurfaces,composed of a number of subwavelength passive or active meta-atoms,have recently found to be a new paradigm to actively reshape wireless communication environment in a green way,distinct from conventional works that passively adapt to the surrounding.In this review,we offer a unified perspective on how intelligent metasurfaces can facilitate wireless communication in three manners:signal relay,signal transmitter,and signal processor.We start by the basic modeling of wireless channel and the evolution of metasurfaces from passive,active to intelligent metasurfaces.Integrated with various deep learning algorithms,intelligent metasurfaces adapt to cater for the ever-changing environments without human intervention.Then,we overview specific experimental advancements using intelligent metasurfaces.We conclude by identifying key issues in the practical implementations of intelligent metasurfaces,and surveying new directions,such as gain metasurfaces and knowledge migration.
文摘In an active network, users can insert customized active codes into activenodes, to execute. Thus it needs more resources than those required by conventional networks, andthese resources must be effectively monitored and managed. Management policies in existing OSs aretoo complicated to apply to simple active packets. In this paper, we present new resourcesmanagement policies that are mainly adoped to manage CPU, storage and transmission bandwidth.Namely, we use SPF algorithm to schedule and process active packets, and import an interval queuemethod to allocate transmission bandwidth, and use feedback mechanism to control congestion . At thesame time, we design some experiments on prototype systems with and without resources managementpolicies respectively. The experiments results show that management policies presented by us caneffectively manage resources in active nodes and can improve the performance of active networks.
基金supported by the National Natural Science Foundation of China (61373139, 60903181)the Natural Science Foundation of Jiangsu Province (BK2012833)+1 种基金the Natural Science Foundation of Jiangsu Higher Education (12KJB520011)the Scientific Research Foundation of Nanjing University of Posts and Telecommunications (NY213161)
文摘The spray and wait protocol is a classic copy-limited spraying protocol in delay tolerant networks, in which, the binary spray mode can be improved for heterogeneous delay tolerant networks. In this article, a new conception of node activity was defined to weigh the importance of nodes in aspect of message dissemination in the whole network. A new spray and wait protocol with node activity was proposed to improve the performance in heterogeneous delay tolerant networks. A mathematical model used under varieties of the spraying protocols was also proposed to analyze the expected delay of the protocol. Simulations show that the spray token proportion with node activity is optimal and the new protocol is of better performance than other related protocols. Therefore, this protocol has high efficiency and good scalability.
