简要介绍网络模拟软件N S(N etw ork S im u lator),分析网络模拟软件N S在教学中应用的优点。认为N S应用于计算机网络课程进行辅助教学和辅助实验具有经济性、方便性、针对性和可重复性等优点。提出应用网络模拟软件N S进行课堂演示...简要介绍网络模拟软件N S(N etw ork S im u lator),分析网络模拟软件N S在教学中应用的优点。认为N S应用于计算机网络课程进行辅助教学和辅助实验具有经济性、方便性、针对性和可重复性等优点。提出应用网络模拟软件N S进行课堂演示、实验比较、设计开发三种教学。这样可以让学生通过观看网络运作动画、分析网络性能结果和设计简单网络实体,能让学生更容易、深入地理解网络协议和算法的复杂行为,收到更好的教学效果。展开更多
The mechanisms of TCP’s retransmission and reset will result in redundant packets. These redundant packets are often sent unnecessarily to the user over a slow last-hop link delaying useful traffic. This is a problem...The mechanisms of TCP’s retransmission and reset will result in redundant packets. These redundant packets are often sent unnecessarily to the user over a slow last-hop link delaying useful traffic. This is a problem for wide-area wireless links, such as General Packet Radio Service (GPRS), because unnecessary transmissions waste already limited radio bandwidth, battery power at the mobile terminal and incurs monetary cost due to charging by data volume. The paper first describes a GPRS model, then discusses how to eliminate the redundant packets in GPRS network and presents the simulation results in Network Simulation 2 (NS 2). The more traffic is, the more the network can benefit. In heavy traffic, it can even get more than 30% improvement in throughput. Average delay and loss percent are also lowered.展开更多
Considering wireless sensor network characteristics,this paper uses network simulator,version2(NS-2)algorithm to improve Ad hoc on-demand distance vector(AODV)routing algorithm,so that it can be applied to wireless se...Considering wireless sensor network characteristics,this paper uses network simulator,version2(NS-2)algorithm to improve Ad hoc on-demand distance vector(AODV)routing algorithm,so that it can be applied to wireless sensor networks.After studying AODV routing protocol,a new algorithm called Must is brought up.This paper introduces the background and algorithm theory of Must,and discusses the details about how to implement Must algorithm.At last,using network simulator(NS-2),the performance of Must is evaluated and compared with that of AODV.Simulation results show that the network using Must algorithm has perfect performance.展开更多
Broadcasting is a basic technique in Mobile ad-hoc network(MANET),and it refers to sending a packet from one node to every other node within the transmission range.Flooding is a type of broadcast where the received pa...Broadcasting is a basic technique in Mobile ad-hoc network(MANET),and it refers to sending a packet from one node to every other node within the transmission range.Flooding is a type of broadcast where the received packet is retransmitted once by every node.The naive flooding technique,floods the network with query messages,while the random walk technique operates by contacting the subsets of every node’s neighbors at each step,thereby restricting the search space.One of the key challenges in an ad-hoc network is the resource or content discovery problem which is about locating the queried resource.Many earlier works have mainly focused on the simulation-based analysis of flooding,and its variants under a wired network.Although,there have been some empirical studies in peer-to-peer(P2P)networks,the analytical results are still lacking,especially in the context of P2P systems running over MANET.In this paper,we describe how P2P resource discovery protocols perform badly over MANETs.To address the limitations,we propose a new protocol named ABRW(Address Broadcast Random Walk),which is a lightweight search approach,designed considering the underlay topology aimed to better suit the unstructured architecture.We provide the mathematical model,measuring the performance of our proposed search scheme with different widely popular benchmarked search techniques.Further,we also derive three relevant search performance metrics,i.e.,mean no.of steps needed to find a resource,the probability of finding a resource,and the mean no.of message overhead.We validated the analytical expressions through simulations.The simulation results closely matched with our analyticalmodel,justifying our findings.Our proposed search algorithm under such highly dynamic self-evolving networks performed better,as it reduced the search latency,decreased the overall message overhead,and still equally had a good success rate.展开更多
Objective To explore the pharmacological mechanism of active saponin compounds of Tuchao Baibiandouren(Lablab Semen Album fried with earth,TCBBDR)in treating type 2 diabetes(T2DM)using UHPLC-Q-Exactive Orbitrap MS and...Objective To explore the pharmacological mechanism of active saponin compounds of Tuchao Baibiandouren(Lablab Semen Album fried with earth,TCBBDR)in treating type 2 diabetes(T2DM)using UHPLC-Q-Exactive Orbitrap MS and network pharmacology.Methods UHPLC-Q-Exactive Orbitrap MS was used for a qualitative analysis of saponin compounds in TCBBDR.PharmMapper and CTD were used to screen drug active compounds and disease targets,and an active compound-target network was constructed via Cytoscape 3.8.0.Molecular docking was applied with the drug active compounds and key targets using AutoDock Vina 1.1.2,and a trajectory for the molecular dynamics simulation was completed by GROMACS 2019-3.Results Sixteen saponin compounds were identified from TCBBDR,along with 292 saponin compoud targets and 792 T2DM targets.Through Venn analysis of target saponin constituents and T2DM related targets,a total of 91 intersection targets were screened out in the treatment of T2DM with saponin.The mean values of degree,betweenness centrality and closeness centrality were taken as the thresholds to screen out 22 key genes,among which 4 key proteins namely MAPK1,IGF1 EGFR,PIK3R1 were selected in the top 10 key genes.On this basis,the saponin active constituent-target-signaling pathway network was established.The Gene Ontology(GO)enrichment analysis showed that the related biological modules included activity of steroid hormone receptor,steroid binding,and insulin receptor binding,etc.;the related signaling pathways were EGFR,PI3K-Akt and MAPK,etc.;regulating signaling pathways like MAPK could induce the proliferation,inhibition and apoptosis of pancreaticβcells,increase the quantity of pancreaticβcells,improve the functions of pancreaticβcells and stimulate the insulin secretion.Docking experiment analysis showed that all selected saponin compounds could enter the active sites of targets and form 3–14 hydrogen bonds with residues of the active sites.Moreover,van der Waals forces were present between chemical compounds and active sites.By combining the docking binding energy,we determined that the chemical compounds showed strong binding energy to the targets.Conclusion TCBBDR exerts therapeutic effects on diabetes through multi-compound and multi-target collaboration.Specifically,saponin components mediate pathways including inflammatory reaction and signal transduction to treat T2DM by regulating several key proteins that interact with EGFR and a series of signaling pathways related to disease development.展开更多
Recently the Cognitive Radio (CR), in particular the CR Ad-Hoc Network (CRAHN) technology appears as a burgeoning area in wireless communication that enables utilization of limited network resources in more efficient ...Recently the Cognitive Radio (CR), in particular the CR Ad-Hoc Network (CRAHN) technology appears as a burgeoning area in wireless communication that enables utilization of limited network resources in more efficient and intelligent way;studies indicate that opportunistic utilization of the available radio frequency spectrum, without interfering the licensed primary user (PU) could be made. This paper presents some simulation based performance of the Multi-Channel Hidden Terminal (MCHT) problem on CRAHNs;new observations on the effect of the number of channels on certain PU-activity metrics, e.g., delay and throughput, are described.展开更多
The peer-to-peer（P2P） file-sharing network as a vehicle of disseminating files has become very popular. The appearance of dozens of kinds of passive worms on this network has, however, made it unsecured. This proble...The peer-to-peer（P2P） file-sharing network as a vehicle of disseminating files has become very popular. The appearance of dozens of kinds of passive worms on this network has, however, made it unsecured. This problem has been paid attention and a few of models for passive worm propagation has been presented. Unfortunately, the dynamic properties of this network are ignored in these models. Given the fact, the characteristics of both this network and the passive worm are identified, and on this basis a new mathematical model of passive worm propagation on the P2P network is presented in applying epidemiology in this paper. Note that the dynamic properties of this network are considered in the presented model. The model has been validated by large scale simulation experiments, which demonstrates that the presented model may be used for analyzing the behaviors of passive worms and predicting the trend of their propagation.展开更多
Integrating the power grid technology with renewable power generation technologies, Demand Response (DR) programs enabled by the Advanced Metering Infrastructure (AMI) were introduced into the power grid in the intere...Integrating the power grid technology with renewable power generation technologies, Demand Response (DR) programs enabled by the Advanced Metering Infrastructure (AMI) were introduced into the power grid in the interest of both utilities and residents. They help to achieve load balance and increase the grid reliability by encouraging residents to reduce their power usage during peak load periods in return for incentives. To automate this process, appliances, in-house sensors, and the AMI controller need to be networked together. In this paper, we compare mainstream network technologies applicable to home appliance control and propose a solution combining Power Line Communication (PLC) with wireless communication in smart homes for the purpose of energy saving. We extended NS-2, a popular network simulator, to model such combined network scenarios. Using a number of different routing strategies, we then model and evaluate the network performance of DR programs in smart homes in such a combined network.展开更多
This paper analyzes the characteristics of the Peer-to-Peer （P2P） active worm and its attacking mechanism, and then proposes a mathematical model of propagation of the P2P active worm applying Epidemiology. Based on...This paper analyzes the characteristics of the Peer-to-Peer （P2P） active worm and its attacking mechanism, and then proposes a mathematical model of propagation of the P2P active worm applying Epidemiology. Based on the analysis on the protocols of realistic P2P systems, a software which can be used to simulate the P2P network environment and the propagation of P2P active worm is imple- mented in this paper. A large number of simulation experiments are performed using the developed simulation software. The results from these simulation experiments validate the proposed model, which means that the model can be used to analyze the spreading behaviors of the P2P active worm and predict its trend.展开更多
This work presents a multi-criteria analysis of the MAC （media access control） layer misbehavior of the IEEE （Institute of Electrical and Electronics Engineers） 802.11 standard, whose principle is to cheat at the ...This work presents a multi-criteria analysis of the MAC （media access control） layer misbehavior of the IEEE （Institute of Electrical and Electronics Engineers） 802.11 standard, whose principle is to cheat at the protocol to increase the transmission rate by greedy nodes at the expense of the other honest nodes. In fact, IEEE 802.11 forces nodes for access to the channel to wait for a back off interval, randomly selected from a specified range, before initiating a transmission. Greedy nodes may wait for smaller back-off intervals than honest nodes, and then obtaining an unfair assignment. In the first of our works a state of art on the research on IEEE 802.11 MAC layer misbehavior are presented. Then the impact of this misbehavior at the reception is given, and we will generalize this impact on a large scale. An analysis of the correlation between the throughput and the inter-packets time is given. Afterwards, we will define a new metric for measuring the performance and capability of the network.展开更多
In many traditional On Demand routing algorithms in Ad hoc wireless networks, a simple flooding mechanism is used to broadcast route request (RREQ) packets when there is a need to establish a route from a source node ...In many traditional On Demand routing algorithms in Ad hoc wireless networks, a simple flooding mechanism is used to broadcast route request (RREQ) packets when there is a need to establish a route from a source node to a destination node. The broadcast of RREQ may lead to high channel contention, high packet collisions, and thus high delay to establish the routes, especially with high density networks. Ad hoc on Demand Distance Vector Routing Protocol (AODV) is one among the most effective Reactive Routing Protocols in MANETs which use simple flooding mechanism to broadcast the RREQ. It is also used in Wireless Sensor Networks (WSN) and in Vehicular Ad hoc Networks (VANET). This paper proposes a new modified AODV routing protocol EGBB-AODV where the RREQ mechanism is using a grid based broadcast (EGBB) which reduces considerably the number of rebroadcast of RREQ packets, and hence improves the performance of the routing protocol. We developed a simulation model based on NS2 simulator to measure the performance of EGBB-AODV and compare the results to the original AODV and a position-aware improved counter-based algorithm (PCB-AODV). The simulation experiments that EGBB-AODV outperforms AODV and PCB-AODV in terms of end-to-end delay, delivery ratio and power consumption, under different traffic load, and network density conditions.展开更多
The topology control is one of the research focuses in wireless sensor networks. Different network topologies will have different effects on the properties of the network, such as the reliability, energy consumption a...The topology control is one of the research focuses in wireless sensor networks. Different network topologies will have different effects on the properties of the network, such as the reliability, energy consumption and latency. In order to study the relationship between the topology and the network performance, in this paper we have designed three kinds of topology models which are regular hexagon topology model, plane grid topology model and equilateral triangle topology model. Then the simulation experiments about these models have been implemented in NS2 and the simulation results show that the plane grid topology has the best reliability.展开更多
Telecommunications and information technology rapidly migrate towards the Future Internet (FI) era, which is characterized by powerful and complex network infrastructures, advanced applications, services and content, ...Telecommunications and information technology rapidly migrate towards the Future Internet (FI) era, which is characterized by powerful and complex network infrastructures, advanced applications, services and content, efficient power management as well as extensions in the business model. One of the main application areas that find prosper ground in the FI era, is medicine. In particular, latest advances in medical sciences are reflected on their capability to approach previously past-cure diseases, as well as to prevent the appearance and evolution of unpleasant situations. Those advances are often derived from interdisciplinary solutions to complex medical problems, supported by communications and electronics, which target fast, reliable and stable solutions to problems that are demanding in terms of velocity and accuracy. The goal of this paper is to present intelligent, knowledge-based management functionality capable of supporting emergency medical applications. An indicative emergency medical scenario is provided, along with extensive simulation results using the Network Simulator-2 (NS-2), for evaluating the performance of the proposed functionality.展开更多
This article analyses key technology used by network layer based on ZigBee technology. Then a reconfigure network as well as its strategy of forming network and distributing node is given. The simulation proved that t...This article analyses key technology used by network layer based on ZigBee technology. Then a reconfigure network as well as its strategy of forming network and distributing node is given. The simulation proved that the stability of reconfigure network and the ability of transmitting pass through obstacle are better than tradi-tional network;it has an active significance for shorter delay because of the flexible of the improved forming network strategy.展开更多
In this research, we have projected and carried out a novel fishbone network that shows better performance in the term of minimizing the packet delay with respect to sink speed. Previous study implies that sector angl...In this research, we have projected and carried out a novel fishbone network that shows better performance in the term of minimizing the packet delay with respect to sink speed. Previous study implies that sector angle affects greatly on designing fishbone network. Finite Set of nodes arranges to sense the physical condition of any system is called wireless sensor. Our designed fishbone network can be potentially applied for a wireless sensing system to formulate a whole network. The network is a novel design which has been finalized by comparing sector angle. Analysis takes place by varying packet delay according to sink speed. Future analysis takes place for Quality of Service (QoS) and Quality of Experience (QoE). Latency of Packet and its size is the measurement criteria of any network or service is called Quality of Service (QoS). On the other hand the user experience of using the designed network is called Quality of Experience (QoE). Our designed network has been analyzed in TCP Tracer to find out the latency or packet delay for different users. The user data has been shorted and equated among them for latency with different no of packets. Our proposed spiral fishbone network shows better QoS and QoE. In future more nodes can be added to design extended fishbone network for wireless.展开更多
文摘简要介绍网络模拟软件N S(N etw ork S im u lator),分析网络模拟软件N S在教学中应用的优点。认为N S应用于计算机网络课程进行辅助教学和辅助实验具有经济性、方便性、针对性和可重复性等优点。提出应用网络模拟软件N S进行课堂演示、实验比较、设计开发三种教学。这样可以让学生通过观看网络运作动画、分析网络性能结果和设计简单网络实体,能让学生更容易、深入地理解网络协议和算法的复杂行为,收到更好的教学效果。
文摘The mechanisms of TCP’s retransmission and reset will result in redundant packets. These redundant packets are often sent unnecessarily to the user over a slow last-hop link delaying useful traffic. This is a problem for wide-area wireless links, such as General Packet Radio Service (GPRS), because unnecessary transmissions waste already limited radio bandwidth, battery power at the mobile terminal and incurs monetary cost due to charging by data volume. The paper first describes a GPRS model, then discusses how to eliminate the redundant packets in GPRS network and presents the simulation results in Network Simulation 2 (NS 2). The more traffic is, the more the network can benefit. In heavy traffic, it can even get more than 30% improvement in throughput. Average delay and loss percent are also lowered.
文摘Considering wireless sensor network characteristics,this paper uses network simulator,version2(NS-2)algorithm to improve Ad hoc on-demand distance vector(AODV)routing algorithm,so that it can be applied to wireless sensor networks.After studying AODV routing protocol,a new algorithm called Must is brought up.This paper introduces the background and algorithm theory of Must,and discusses the details about how to implement Must algorithm.At last,using network simulator(NS-2),the performance of Must is evaluated and compared with that of AODV.Simulation results show that the network using Must algorithm has perfect performance.
文摘Broadcasting is a basic technique in Mobile ad-hoc network(MANET),and it refers to sending a packet from one node to every other node within the transmission range.Flooding is a type of broadcast where the received packet is retransmitted once by every node.The naive flooding technique,floods the network with query messages,while the random walk technique operates by contacting the subsets of every node’s neighbors at each step,thereby restricting the search space.One of the key challenges in an ad-hoc network is the resource or content discovery problem which is about locating the queried resource.Many earlier works have mainly focused on the simulation-based analysis of flooding,and its variants under a wired network.Although,there have been some empirical studies in peer-to-peer(P2P)networks,the analytical results are still lacking,especially in the context of P2P systems running over MANET.In this paper,we describe how P2P resource discovery protocols perform badly over MANETs.To address the limitations,we propose a new protocol named ABRW(Address Broadcast Random Walk),which is a lightweight search approach,designed considering the underlay topology aimed to better suit the unstructured architecture.We provide the mathematical model,measuring the performance of our proposed search scheme with different widely popular benchmarked search techniques.Further,we also derive three relevant search performance metrics,i.e.,mean no.of steps needed to find a resource,the probability of finding a resource,and the mean no.of message overhead.We validated the analytical expressions through simulations.The simulation results closely matched with our analyticalmodel,justifying our findings.Our proposed search algorithm under such highly dynamic self-evolving networks performed better,as it reduced the search latency,decreased the overall message overhead,and still equally had a good success rate.
基金We thank for the funding support from the Program of Survey of Chinese Medicines of China(No.[2017]66).
文摘Objective To explore the pharmacological mechanism of active saponin compounds of Tuchao Baibiandouren(Lablab Semen Album fried with earth,TCBBDR)in treating type 2 diabetes(T2DM)using UHPLC-Q-Exactive Orbitrap MS and network pharmacology.Methods UHPLC-Q-Exactive Orbitrap MS was used for a qualitative analysis of saponin compounds in TCBBDR.PharmMapper and CTD were used to screen drug active compounds and disease targets,and an active compound-target network was constructed via Cytoscape 3.8.0.Molecular docking was applied with the drug active compounds and key targets using AutoDock Vina 1.1.2,and a trajectory for the molecular dynamics simulation was completed by GROMACS 2019-3.Results Sixteen saponin compounds were identified from TCBBDR,along with 292 saponin compoud targets and 792 T2DM targets.Through Venn analysis of target saponin constituents and T2DM related targets,a total of 91 intersection targets were screened out in the treatment of T2DM with saponin.The mean values of degree,betweenness centrality and closeness centrality were taken as the thresholds to screen out 22 key genes,among which 4 key proteins namely MAPK1,IGF1 EGFR,PIK3R1 were selected in the top 10 key genes.On this basis,the saponin active constituent-target-signaling pathway network was established.The Gene Ontology(GO)enrichment analysis showed that the related biological modules included activity of steroid hormone receptor,steroid binding,and insulin receptor binding,etc.;the related signaling pathways were EGFR,PI3K-Akt and MAPK,etc.;regulating signaling pathways like MAPK could induce the proliferation,inhibition and apoptosis of pancreaticβcells,increase the quantity of pancreaticβcells,improve the functions of pancreaticβcells and stimulate the insulin secretion.Docking experiment analysis showed that all selected saponin compounds could enter the active sites of targets and form 3–14 hydrogen bonds with residues of the active sites.Moreover,van der Waals forces were present between chemical compounds and active sites.By combining the docking binding energy,we determined that the chemical compounds showed strong binding energy to the targets.Conclusion TCBBDR exerts therapeutic effects on diabetes through multi-compound and multi-target collaboration.Specifically,saponin components mediate pathways including inflammatory reaction and signal transduction to treat T2DM by regulating several key proteins that interact with EGFR and a series of signaling pathways related to disease development.
文摘Recently the Cognitive Radio (CR), in particular the CR Ad-Hoc Network (CRAHN) technology appears as a burgeoning area in wireless communication that enables utilization of limited network resources in more efficient and intelligent way;studies indicate that opportunistic utilization of the available radio frequency spectrum, without interfering the licensed primary user (PU) could be made. This paper presents some simulation based performance of the Multi-Channel Hidden Terminal (MCHT) problem on CRAHNs;new observations on the effect of the number of channels on certain PU-activity metrics, e.g., delay and throughput, are described.
文摘The peer-to-peer（P2P） file-sharing network as a vehicle of disseminating files has become very popular. The appearance of dozens of kinds of passive worms on this network has, however, made it unsecured. This problem has been paid attention and a few of models for passive worm propagation has been presented. Unfortunately, the dynamic properties of this network are ignored in these models. Given the fact, the characteristics of both this network and the passive worm are identified, and on this basis a new mathematical model of passive worm propagation on the P2P network is presented in applying epidemiology in this paper. Note that the dynamic properties of this network are considered in the presented model. The model has been validated by large scale simulation experiments, which demonstrates that the presented model may be used for analyzing the behaviors of passive worms and predicting the trend of their propagation.
文摘Integrating the power grid technology with renewable power generation technologies, Demand Response (DR) programs enabled by the Advanced Metering Infrastructure (AMI) were introduced into the power grid in the interest of both utilities and residents. They help to achieve load balance and increase the grid reliability by encouraging residents to reduce their power usage during peak load periods in return for incentives. To automate this process, appliances, in-house sensors, and the AMI controller need to be networked together. In this paper, we compare mainstream network technologies applicable to home appliance control and propose a solution combining Power Line Communication (PLC) with wireless communication in smart homes for the purpose of energy saving. We extended NS-2, a popular network simulator, to model such combined network scenarios. Using a number of different routing strategies, we then model and evaluate the network performance of DR programs in smart homes in such a combined network.
文摘This paper analyzes the characteristics of the Peer-to-Peer （P2P） active worm and its attacking mechanism, and then proposes a mathematical model of propagation of the P2P active worm applying Epidemiology. Based on the analysis on the protocols of realistic P2P systems, a software which can be used to simulate the P2P network environment and the propagation of P2P active worm is imple- mented in this paper. A large number of simulation experiments are performed using the developed simulation software. The results from these simulation experiments validate the proposed model, which means that the model can be used to analyze the spreading behaviors of the P2P active worm and predict its trend.
文摘This work presents a multi-criteria analysis of the MAC （media access control） layer misbehavior of the IEEE （Institute of Electrical and Electronics Engineers） 802.11 standard, whose principle is to cheat at the protocol to increase the transmission rate by greedy nodes at the expense of the other honest nodes. In fact, IEEE 802.11 forces nodes for access to the channel to wait for a back off interval, randomly selected from a specified range, before initiating a transmission. Greedy nodes may wait for smaller back-off intervals than honest nodes, and then obtaining an unfair assignment. In the first of our works a state of art on the research on IEEE 802.11 MAC layer misbehavior are presented. Then the impact of this misbehavior at the reception is given, and we will generalize this impact on a large scale. An analysis of the correlation between the throughput and the inter-packets time is given. Afterwards, we will define a new metric for measuring the performance and capability of the network.
文摘In many traditional On Demand routing algorithms in Ad hoc wireless networks, a simple flooding mechanism is used to broadcast route request (RREQ) packets when there is a need to establish a route from a source node to a destination node. The broadcast of RREQ may lead to high channel contention, high packet collisions, and thus high delay to establish the routes, especially with high density networks. Ad hoc on Demand Distance Vector Routing Protocol (AODV) is one among the most effective Reactive Routing Protocols in MANETs which use simple flooding mechanism to broadcast the RREQ. It is also used in Wireless Sensor Networks (WSN) and in Vehicular Ad hoc Networks (VANET). This paper proposes a new modified AODV routing protocol EGBB-AODV where the RREQ mechanism is using a grid based broadcast (EGBB) which reduces considerably the number of rebroadcast of RREQ packets, and hence improves the performance of the routing protocol. We developed a simulation model based on NS2 simulator to measure the performance of EGBB-AODV and compare the results to the original AODV and a position-aware improved counter-based algorithm (PCB-AODV). The simulation experiments that EGBB-AODV outperforms AODV and PCB-AODV in terms of end-to-end delay, delivery ratio and power consumption, under different traffic load, and network density conditions.
文摘The topology control is one of the research focuses in wireless sensor networks. Different network topologies will have different effects on the properties of the network, such as the reliability, energy consumption and latency. In order to study the relationship between the topology and the network performance, in this paper we have designed three kinds of topology models which are regular hexagon topology model, plane grid topology model and equilateral triangle topology model. Then the simulation experiments about these models have been implemented in NS2 and the simulation results show that the plane grid topology has the best reliability.
文摘Telecommunications and information technology rapidly migrate towards the Future Internet (FI) era, which is characterized by powerful and complex network infrastructures, advanced applications, services and content, efficient power management as well as extensions in the business model. One of the main application areas that find prosper ground in the FI era, is medicine. In particular, latest advances in medical sciences are reflected on their capability to approach previously past-cure diseases, as well as to prevent the appearance and evolution of unpleasant situations. Those advances are often derived from interdisciplinary solutions to complex medical problems, supported by communications and electronics, which target fast, reliable and stable solutions to problems that are demanding in terms of velocity and accuracy. The goal of this paper is to present intelligent, knowledge-based management functionality capable of supporting emergency medical applications. An indicative emergency medical scenario is provided, along with extensive simulation results using the Network Simulator-2 (NS-2), for evaluating the performance of the proposed functionality.
文摘This article analyses key technology used by network layer based on ZigBee technology. Then a reconfigure network as well as its strategy of forming network and distributing node is given. The simulation proved that the stability of reconfigure network and the ability of transmitting pass through obstacle are better than tradi-tional network;it has an active significance for shorter delay because of the flexible of the improved forming network strategy.
文摘In this research, we have projected and carried out a novel fishbone network that shows better performance in the term of minimizing the packet delay with respect to sink speed. Previous study implies that sector angle affects greatly on designing fishbone network. Finite Set of nodes arranges to sense the physical condition of any system is called wireless sensor. Our designed fishbone network can be potentially applied for a wireless sensing system to formulate a whole network. The network is a novel design which has been finalized by comparing sector angle. Analysis takes place by varying packet delay according to sink speed. Future analysis takes place for Quality of Service (QoS) and Quality of Experience (QoE). Latency of Packet and its size is the measurement criteria of any network or service is called Quality of Service (QoS). On the other hand the user experience of using the designed network is called Quality of Experience (QoE). Our designed network has been analyzed in TCP Tracer to find out the latency or packet delay for different users. The user data has been shorted and equated among them for latency with different no of packets. Our proposed spiral fishbone network shows better QoS and QoE. In future more nodes can be added to design extended fishbone network for wireless.
