To solve the coverage and quality problems caused by cell outage in LTE networks, this paper proposes a distributed self-organizing networks management architecture and a distributed cell outage compensation managemen...To solve the coverage and quality problems caused by cell outage in LTE networks, this paper proposes a distributed self-organizing networks management architecture and a distributed cell outage compensation management mechanism. After detecting and analyzing the outage, a cell outage compensation algorithm based on reference signal power adjustment is proposed. The simulation results show that the proposed mechanism can mitigate the performance degradation significantly. Compared with other algorithms, the proposed scheme is more effective in compensating the coverage gap induced by cell outage展开更多
Failure of one or multiple critical nodes may partition wireless sensor networks into disjoint segments, and thus brings negative effect on the applications. We propose DCRS, a Distributed Connectivity Restoration Str...Failure of one or multiple critical nodes may partition wireless sensor networks into disjoint segments, and thus brings negative effect on the applications. We propose DCRS, a Distributed Connectivity Restoration Strategy to tolerate the failure of one critical node. Because of the energy restriction of sensor nodes, the energy overhead of the recovery process should be minimized to extend the lifetime of the network. To achieve it, we first design a novel algorithm to identify 2-critical nodes only relying on the positional information of 1-hop neighbors and some 2-hop neighbors, and then we present the criteria to select an appropriate backup for each critical node. Finally, we improve the cascaded node movement algorithm by determining whether a node can move to another non-adjacent node directly or not to reduce the number of nodes moved. The effectiveness of DCRS is validated through extensive simulation experiments.展开更多
WSN has been developing from traditional environment monitoring applications to the ubiquitous information services such as the Congestion-oriented Intelligent Transportation System （ColTS）. However, the mobility of...WSN has been developing from traditional environment monitoring applications to the ubiquitous information services such as the Congestion-oriented Intelligent Transportation System （ColTS）. However, the mobility of nodes makes data dissemination a hard nut to crack. In this paper, we propose MSDD, a multiple mobile sinks data dissemination mechanism for solving the dissemination problem. The main ideas of MSDD are constructing a two-tier grid structure by a designated sink, exploiting a hierarchical monitoring mechanism, and employing a global agent to track the sink locations in order to make the emergencies reported to the sinks immediately, In addition, MSDD supports the query-driven data dissemination. Being compared with TTDD, MSDD is theoretically proved to have less communication overhead. We also validate MSDD outperforms TTDD in reliability and the emergency delivery latency bv simulations.展开更多
It is a challenge to select an optimal set of devices to accomplish a graph-based ubiquitous service and execute it continuously under the circumstances of dynamic environments and limited device capability. We elabor...It is a challenge to select an optimal set of devices to accomplish a graph-based ubiquitous service and execute it continuously under the circumstances of dynamic environments and limited device capability. We elaborate a Synergy- aware Selection Mechanism （SSM） considering synergetic among devices. In the SSM, we design a distributed algorithm to integrate the devices and a dynamic updating weight method. The simulation results show that SSM can make devices composed together to ensure the continuity and smoothness of service展开更多
In ubiquitous stub environment, it is a critical challenge to design an optimal device aggregation mechanism to meet all requested ubiquitous services simultaneously with resource- limited devices and bandwidth-limite...In ubiquitous stub environment, it is a critical challenge to design an optimal device aggregation mechanism to meet all requested ubiquitous services simultaneously with resource- limited devices and bandwidth-limited network. Firstly, Multi-Service oriented Devices Aggregation Problem is generalized and formulated based on QoS-metric with Multi-attribute Decision Making. Secondly, a Multi-Service oriented Devices Aggregation Mechanism is proposed to deal the problem in which there are two processes： Dimensionless Processing and Device Aggregation Approach. At last, the simulation is implemented with OPNET and MATLAB. We integrate different QoS factors, such as Average Utility, Utility distribution, Total Utility distribution and Service Failure Rate, to reflect user experience.展开更多
文摘To solve the coverage and quality problems caused by cell outage in LTE networks, this paper proposes a distributed self-organizing networks management architecture and a distributed cell outage compensation management mechanism. After detecting and analyzing the outage, a cell outage compensation algorithm based on reference signal power adjustment is proposed. The simulation results show that the proposed mechanism can mitigate the performance degradation significantly. Compared with other algorithms, the proposed scheme is more effective in compensating the coverage gap induced by cell outage
文摘Failure of one or multiple critical nodes may partition wireless sensor networks into disjoint segments, and thus brings negative effect on the applications. We propose DCRS, a Distributed Connectivity Restoration Strategy to tolerate the failure of one critical node. Because of the energy restriction of sensor nodes, the energy overhead of the recovery process should be minimized to extend the lifetime of the network. To achieve it, we first design a novel algorithm to identify 2-critical nodes only relying on the positional information of 1-hop neighbors and some 2-hop neighbors, and then we present the criteria to select an appropriate backup for each critical node. Finally, we improve the cascaded node movement algorithm by determining whether a node can move to another non-adjacent node directly or not to reduce the number of nodes moved. The effectiveness of DCRS is validated through extensive simulation experiments.
基金This work was supported in part by China National Natural Science Foundation under Grant 61271185,and the Fundamental Research Funds for the Central Universities
文摘WSN has been developing from traditional environment monitoring applications to the ubiquitous information services such as the Congestion-oriented Intelligent Transportation System （ColTS）. However, the mobility of nodes makes data dissemination a hard nut to crack. In this paper, we propose MSDD, a multiple mobile sinks data dissemination mechanism for solving the dissemination problem. The main ideas of MSDD are constructing a two-tier grid structure by a designated sink, exploiting a hierarchical monitoring mechanism, and employing a global agent to track the sink locations in order to make the emergencies reported to the sinks immediately, In addition, MSDD supports the query-driven data dissemination. Being compared with TTDD, MSDD is theoretically proved to have less communication overhead. We also validate MSDD outperforms TTDD in reliability and the emergency delivery latency bv simulations.
文摘It is a challenge to select an optimal set of devices to accomplish a graph-based ubiquitous service and execute it continuously under the circumstances of dynamic environments and limited device capability. We elaborate a Synergy- aware Selection Mechanism （SSM） considering synergetic among devices. In the SSM, we design a distributed algorithm to integrate the devices and a dynamic updating weight method. The simulation results show that SSM can make devices composed together to ensure the continuity and smoothness of service
文摘In ubiquitous stub environment, it is a critical challenge to design an optimal device aggregation mechanism to meet all requested ubiquitous services simultaneously with resource- limited devices and bandwidth-limited network. Firstly, Multi-Service oriented Devices Aggregation Problem is generalized and formulated based on QoS-metric with Multi-attribute Decision Making. Secondly, a Multi-Service oriented Devices Aggregation Mechanism is proposed to deal the problem in which there are two processes： Dimensionless Processing and Device Aggregation Approach. At last, the simulation is implemented with OPNET and MATLAB. We integrate different QoS factors, such as Average Utility, Utility distribution, Total Utility distribution and Service Failure Rate, to reflect user experience.
