Ethereum, currently the most widely utilized smart contracts platform, anchors the security of myriad smartcontracts upon its own robustness. Its foundational peer-to-peer network facilitates a dependable node connect...Ethereum, currently the most widely utilized smart contracts platform, anchors the security of myriad smartcontracts upon its own robustness. Its foundational peer-to-peer network facilitates a dependable node connectionmechanism, whereas an efficient data-sharing protocol constitutes as the bedrock of Blockchain network security.In this paper, we propose NodeHunter, an Ethereum network detector implemented through the application ofsimulation technology, which is capable of aggregating all node records within the network and the interconnectednessbetween them. Utilizing this connection information, NodeHunter can procure more comprehensive insightsfor network status analysis compared to preceding detection methodologies. Throughout a three-month period ofunbroken surveillance of the Ethereum network, we obtained an excess of two million node records along with overone hundred million node acquaintances. Analysis of the gathered data revealed that an alarming 49% or more ofthese node records were maliciously forged.展开更多
In order to reduce the maintenance cost of structured Peer-to-Peer (P2P),Clone Node Protocol (CNP) based on user behavior is proposed.CNP considers the regularity of user behavior and uses the method of clone node.A B...In order to reduce the maintenance cost of structured Peer-to-Peer (P2P),Clone Node Protocol (CNP) based on user behavior is proposed.CNP considers the regularity of user behavior and uses the method of clone node.A Bidirectional Clone Node Chord model (BCNChord) based on CNP protocol is designed and realized.In BCNChord,Anticlockwise Searching Algorithm,Difference Push Synchronize Algorithm and Optimal Maintenance Algorithm are put forward to increase the performances.In experiments,according to the frequency of nodes,the maintenance cost of BCNChord can be 3.5%～32.5% lower than that of Chord.In the network of 212 nodes,the logic path hop is steady at 6,which is much more prior to 12 of Chord and 10 of CNChord.Theoretical analysis and experimental results show that BCNChord can effectively reduce the maintenance cost of its structure and simultaneously improve the query efficiency up to (1/4)O(logN).BCNChord is more suitable for highly dynamic environment and higher real-time system.展开更多
The occurrence of‘sensing holes’not only hinders seamless data col-lection but also leads to misinterpretation of information in certain areas under extensive data analysis.In order to overcome this,various sensor r...The occurrence of‘sensing holes’not only hinders seamless data col-lection but also leads to misinterpretation of information in certain areas under extensive data analysis.In order to overcome this,various sensor relocation stra-tegies have been proposed,but the existing relocation strategies revealed pro-blems such as the ping-pong,shaded area,network disconnection,etc.This paper conducted research on relocation protocols in a distributed environment that is very suitable for real-world situations and efficiently recovering the problem of sensing holes.First,a simulation was performed on the distribution of the shaded area for data collection,which is a problem with the existing representative relo-cation protocol.After that,a data collection capability was newly added to the relay node,which had been in charge of only communication between cluster zones so far,and with this additional functionality,the performance of the revised sensor relocation algorithm was dramatically improved to overcome the existing problems.In addition,the performance and validity of the proposed algorithm were verified through various simulations.展开更多
The security problems of wireless sensor networks (WSN) have attracted people’s wide attention. In this paper, after we have summarized the existing security problems and solutions in WSN, we find that the insider at...The security problems of wireless sensor networks (WSN) have attracted people’s wide attention. In this paper, after we have summarized the existing security problems and solutions in WSN, we find that the insider attack to WSN is hard to solve. Insider attack is different from outsider attack, because it can’t be solved by the traditional encryption and message authentication. Therefore, a reliable secure routing protocol should be proposed in order to defense the insider attack. In this paper, we focus on insider selective forwarding attack. The existing detection mechanisms, such as watchdog, multipath retreat, neighbor-based monitoring and so on, have both advantages and disadvantages. According to their characteristics, we proposed a secure routing protocol based on monitor node and trust mechanism. The reputation value is made up with packet forwarding rate and node’s residual energy. So this detection and routing mechanism is universal because it can take account of both the safety and lifetime of network. Finally, we use OPNET simulation to verify the performance of our algorithm.展开更多
Accurate time synchronization is fundamental to the correct and efficient operation of Wireless Sensor Networks(WSNs),especially in security-critical,time-sensitive applications.However,most existing protocols degrade...Accurate time synchronization is fundamental to the correct and efficient operation of Wireless Sensor Networks(WSNs),especially in security-critical,time-sensitive applications.However,most existing protocols degrade substantially under malicious interference.We introduce iSTSP,an Intelligent and Secure Time Synchronization Protocol that implements a four-stage defense pipeline to ensure robust,precise synchronization even in hostile environments:(1)trust preprocessing that filters node participation using behavioral trust scoring;(2)anomaly isolation employing a lightweight autoencoder to detect and excise malicious nodes in real time;(3)reliability-weighted consensus that prioritizes high-trust nodes during time aggregation;and(4)convergence-optimized synchronization that dynamically adjusts parameters using theoretical stability bounds.We provide rigorous convergence analysis including a closed-form expression for convergence time,and validate the protocol through both simulations and realworld experiments on a controlled 16-node testbed.Under Sybil attacks with five malicious nodes within this testbed,iSTSP maintains synchronization error increases under 12%and achieves a rapid convergence.Compared to state-ofthe-art protocols like TPSN,SE-FTSP,and MMAR-CTS,iSTSP offers 60%faster detection,broader threat coverage,and more than 7 times lower synchronization error,with a modest 9.3%energy overhead over 8 h.We argue this is an acceptable trade-off for mission-critical deployments requiring guaranteed security.These findings demonstrate iSTSP’s potential as a reliable solution for secure WSN synchronization and motivate future work on large-scale IoT deployments and integration with energy-efficient communication protocols.展开更多
Since mobile nodes such as autonomous underwater vehicles can effectively expand network coverage,underwater acoustic networks with mobile nodes have attracted more and more attention in recent years.To ensure the tim...Since mobile nodes such as autonomous underwater vehicles can effectively expand network coverage,underwater acoustic networks with mobile nodes have attracted more and more attention in recent years.To ensure the timely access of a mobile node without disturbing the normal transmission of data packets from static nodes,a sequence-scheduled and query-based medium access control protocol is proposed in this paper.The underwater nodes with data packets to be transmitted reply with a control packet for channel reservation after receiving the broadcast control packet of the buoy,then the reserved nodes transmit their data packets as the order calculated by the buoy.We develop a mechanism to adjust the transmission order of the control packets sent by the underwater nodes in the handshake phase to reduce the collision and guarantee the success rate of reservation,and a query is initiated when the reserved control packet of the mobile node is not received by the buoy in the handshake to respond to the data transmission request of the mobile node in time.Simulations show that the maximum nodal throughput of the proposed MAC protocol increases by at least 20%and the access delay of the mobile node decreases by about 90%,compared to the two reference protocols.Besides,the average access probability of the mobile node in the proposed protocol is more than 90%.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
无线传感器网络(WSNs)的运行效果对保证网络定位精度具有重要的意义。由于网络定位信息数据均可由自组网内节点随机获取,网络定位适用性在先验式路由协议链路状态路由协议(Optimized Link State Routing,OLSR)下表现更好。为了解决OLSR...无线传感器网络(WSNs)的运行效果对保证网络定位精度具有重要的意义。由于网络定位信息数据均可由自组网内节点随机获取,网络定位适用性在先验式路由协议链路状态路由协议(Optimized Link State Routing,OLSR)下表现更好。为了解决OLSR的多点中继(Multpoint Relays,MPR)节点运动速度较快的问题,为此设计了一种基于能量消耗的网络定位OLSR路由协议MPR机制评估方法,并开展仿真分析。研究结果表明:与原协议相比,节点能量消耗MPR选举生成协议表现出的性能更佳,经能量消耗MPR后形成的协议的吞吐量更大,有利于促进网络运行稳定性的提高。展开更多
针对区块链边缘节点的部署环境开放、安全措施薄弱、易受到安全攻击,以及计算和网络资源不足等问题,提出一种基于可信执行环境(TEE)的区块链安全架构P-Dledger。该架构通过构建两阶段的信任链,在满足软件便捷迭代的基础上,确保加载部件...针对区块链边缘节点的部署环境开放、安全措施薄弱、易受到安全攻击,以及计算和网络资源不足等问题,提出一种基于可信执行环境(TEE)的区块链安全架构P-Dledger。该架构通过构建两阶段的信任链,在满足软件便捷迭代的基础上,确保加载部件的可信;通过实现智能合约可信执行框架以及基于串行外设接口或非门存储器(SPI NOR Flash)的数据可信存储,保证智能合约的可信计算与数据的可信存储;同时,为共识提案赋予单调递增的唯一标识,限制拜占庭节点的行为。实验与分析结果表明:所提架构确保了加载主体、账本数据与执行过程的安全可信;当网络延时大于60 ms或节点数大于8时,P-Dledger比采用拜占庭容错(PBFT)算法的区块链系统的吞吐量更高,且随着网络延时与节点数的增加,P-Dledger性能表现更稳定。展开更多
A Light-Weight Simple Network Management Protocol (LW-SNMP) for the wireless sensor network is proposed, which is a kind of hierarchical network management system including a sink manager, cluster proxies, and node ag...A Light-Weight Simple Network Management Protocol (LW-SNMP) for the wireless sensor network is proposed, which is a kind of hierarchical network management system including a sink manager, cluster proxies, and node agents. Considering the resource limitations on the sensor nodes, we design new management messages, new data types and new management information base completely. The management messages between the cluster proxy and node agents are delivered as normal data packets. The experiment results show that LW-SNMP can meet the management demands in the resource-limited wireless sensor networks and has a good performance in stability, effectiveness of memory, extensibility than the traditional Simple Network Management Protocol (SNMP).展开更多
The airspace communication network based on spacecraft has a wide range of applications in regional information enhancement and emergency communication. In this paper, a routing algorithm for congestion degree detecti...The airspace communication network based on spacecraft has a wide range of applications in regional information enhancement and emergency communication. In this paper, a routing algorithm for congestion degree detection of multipath routing (CD_AOMDV) is proposed. The method of combining the whole congestion degree detection and local congestion degree detection before service initiation is adopted. Timely and accurate judgment of the congestion degree reduced the loss rate of the hot nodes, so the average packet loss rate reduced. Simulation results show that compared with the traditional AOMDV protocol, the CD_AOMDV proposed in this paper has reduced the packet loss and improved delay performance, which is more suitable for the airspace communication network.展开更多
The performance of a Mobile Ad hoc Network (MANET) is closely related to the capability of the implemented routing protocol to adapt itself to unpredictable changes of topology network and link status. The Optimized L...The performance of a Mobile Ad hoc Network (MANET) is closely related to the capability of the implemented routing protocol to adapt itself to unpredictable changes of topology network and link status. The Optimized Link State Routing (OLSR) protocol is a one key of the proactive routing protocols for MANETs. It is based on the multi-point relays (MPRs) technique to reach all nodes in the network with a limited number of broadcasts. In this paper, we propose new versions of the original OLSR protocol based on a new mobility parameter, in the goal to enhance and adapt it in the presence of the mobility. For this objective we define new three criterions for MPRs selection. The first criteria take for selection, just the mobility of nodes at one-hop. The two others criterions are based on both mobility of nodes at one-hop and two-hops.展开更多
The application environments of wireless Ad hoc networks require that it should support Quality of Service (QoS). However, that is very difficult because of the inherent characteristics of the wireless channel and the...The application environments of wireless Ad hoc networks require that it should support Quality of Service (QoS). However, that is very difficult because of the inherent characteristics of the wireless channel and the frequent changes of network topology caused by nodes movement. An Ad hoc QoS Multicasting (AQM) protocol can solve this problem by previously reserving the neighbor nodes for tracking resource availability. By considering QoS restrictions of transport delay, loss ratio, bandwidth requirement, delay jitter, and throughout, and by finding the adaptive routing, the AQM protocol can obviously improve the efficiency of multicastsession. The results of network simulation show that QoS is essentially applicable to Ad hoc networks.展开更多
Energy efficiency is the primary issue for the Medium Access Control (MAC) protocol in sensor networks. Adopting periodic sleep,adaptive listen,overhearing avoidance and message passing mechanisms,the Sensor Medium Ac...Energy efficiency is the primary issue for the Medium Access Control (MAC) protocol in sensor networks. Adopting periodic sleep,adaptive listen,overhearing avoidance and message passing mechanisms,the Sensor Medium Access Control (S-MAC) protocol improves energy efficiency and latency in the network. There are mainly two methods to enhance the S-MAC protocol: dynamic adjustment,and sending control and data packets under different transport conditions. For the wireless sensor network,it is not realistic to design one MAC protocol that meets all requirements of every aspect; however,it is possible to design corresponding protocols in accordance with different requirements by flexibly adopting different methods.展开更多
基金the National Key Research and Development Program of China(No.2020YFB1005805)Peng Cheng Laboratory Project(Grant No.PCL2021A02)+2 种基金Guangdong Provincial Key Laboratory of Novel Security Intelligence Technologies(2022B1212010005)Shenzhen Basic Research(General Project)(No.JCYJ20190806142601687)Shenzhen Stable Supporting Program(General Project)(No.GXWD20201230155427003-20200821160539001).
文摘Ethereum, currently the most widely utilized smart contracts platform, anchors the security of myriad smartcontracts upon its own robustness. Its foundational peer-to-peer network facilitates a dependable node connectionmechanism, whereas an efficient data-sharing protocol constitutes as the bedrock of Blockchain network security.In this paper, we propose NodeHunter, an Ethereum network detector implemented through the application ofsimulation technology, which is capable of aggregating all node records within the network and the interconnectednessbetween them. Utilizing this connection information, NodeHunter can procure more comprehensive insightsfor network status analysis compared to preceding detection methodologies. Throughout a three-month period ofunbroken surveillance of the Ethereum network, we obtained an excess of two million node records along with overone hundred million node acquaintances. Analysis of the gathered data revealed that an alarming 49% or more ofthese node records were maliciously forged.
基金supported by the National Natural Science Foundation of China under Grant No.61100205Science and Technology Project of Beijing Municipal Education Commission under Grant No.KM201110016006Doctor Start-up Foundation of BUCEA under Grant No.101002508
文摘In order to reduce the maintenance cost of structured Peer-to-Peer (P2P),Clone Node Protocol (CNP) based on user behavior is proposed.CNP considers the regularity of user behavior and uses the method of clone node.A Bidirectional Clone Node Chord model (BCNChord) based on CNP protocol is designed and realized.In BCNChord,Anticlockwise Searching Algorithm,Difference Push Synchronize Algorithm and Optimal Maintenance Algorithm are put forward to increase the performances.In experiments,according to the frequency of nodes,the maintenance cost of BCNChord can be 3.5%～32.5% lower than that of Chord.In the network of 212 nodes,the logic path hop is steady at 6,which is much more prior to 12 of Chord and 10 of CNChord.Theoretical analysis and experimental results show that BCNChord can effectively reduce the maintenance cost of its structure and simultaneously improve the query efficiency up to (1/4)O(logN).BCNChord is more suitable for highly dynamic environment and higher real-time system.
基金supported by Incheon National University Research Grant in 2021(2021-0295).
文摘The occurrence of‘sensing holes’not only hinders seamless data col-lection but also leads to misinterpretation of information in certain areas under extensive data analysis.In order to overcome this,various sensor relocation stra-tegies have been proposed,but the existing relocation strategies revealed pro-blems such as the ping-pong,shaded area,network disconnection,etc.This paper conducted research on relocation protocols in a distributed environment that is very suitable for real-world situations and efficiently recovering the problem of sensing holes.First,a simulation was performed on the distribution of the shaded area for data collection,which is a problem with the existing representative relo-cation protocol.After that,a data collection capability was newly added to the relay node,which had been in charge of only communication between cluster zones so far,and with this additional functionality,the performance of the revised sensor relocation algorithm was dramatically improved to overcome the existing problems.In addition,the performance and validity of the proposed algorithm were verified through various simulations.
文摘The security problems of wireless sensor networks (WSN) have attracted people’s wide attention. In this paper, after we have summarized the existing security problems and solutions in WSN, we find that the insider attack to WSN is hard to solve. Insider attack is different from outsider attack, because it can’t be solved by the traditional encryption and message authentication. Therefore, a reliable secure routing protocol should be proposed in order to defense the insider attack. In this paper, we focus on insider selective forwarding attack. The existing detection mechanisms, such as watchdog, multipath retreat, neighbor-based monitoring and so on, have both advantages and disadvantages. According to their characteristics, we proposed a secure routing protocol based on monitor node and trust mechanism. The reputation value is made up with packet forwarding rate and node’s residual energy. So this detection and routing mechanism is universal because it can take account of both the safety and lifetime of network. Finally, we use OPNET simulation to verify the performance of our algorithm.
基金this project under Geran Putra Inisiatif(GPI)with reference of GP-GPI/2023/976210。
文摘Accurate time synchronization is fundamental to the correct and efficient operation of Wireless Sensor Networks(WSNs),especially in security-critical,time-sensitive applications.However,most existing protocols degrade substantially under malicious interference.We introduce iSTSP,an Intelligent and Secure Time Synchronization Protocol that implements a four-stage defense pipeline to ensure robust,precise synchronization even in hostile environments:(1)trust preprocessing that filters node participation using behavioral trust scoring;(2)anomaly isolation employing a lightweight autoencoder to detect and excise malicious nodes in real time;(3)reliability-weighted consensus that prioritizes high-trust nodes during time aggregation;and(4)convergence-optimized synchronization that dynamically adjusts parameters using theoretical stability bounds.We provide rigorous convergence analysis including a closed-form expression for convergence time,and validate the protocol through both simulations and realworld experiments on a controlled 16-node testbed.Under Sybil attacks with five malicious nodes within this testbed,iSTSP maintains synchronization error increases under 12%and achieves a rapid convergence.Compared to state-ofthe-art protocols like TPSN,SE-FTSP,and MMAR-CTS,iSTSP offers 60%faster detection,broader threat coverage,and more than 7 times lower synchronization error,with a modest 9.3%energy overhead over 8 h.We argue this is an acceptable trade-off for mission-critical deployments requiring guaranteed security.These findings demonstrate iSTSP’s potential as a reliable solution for secure WSN synchronization and motivate future work on large-scale IoT deployments and integration with energy-efficient communication protocols.
基金This work was supported by National Basic Research Program of China(No.2018YFC1405904).
文摘Since mobile nodes such as autonomous underwater vehicles can effectively expand network coverage,underwater acoustic networks with mobile nodes have attracted more and more attention in recent years.To ensure the timely access of a mobile node without disturbing the normal transmission of data packets from static nodes,a sequence-scheduled and query-based medium access control protocol is proposed in this paper.The underwater nodes with data packets to be transmitted reply with a control packet for channel reservation after receiving the broadcast control packet of the buoy,then the reserved nodes transmit their data packets as the order calculated by the buoy.We develop a mechanism to adjust the transmission order of the control packets sent by the underwater nodes in the handshake phase to reduce the collision and guarantee the success rate of reservation,and a query is initiated when the reserved control packet of the mobile node is not received by the buoy in the handshake to respond to the data transmission request of the mobile node in time.Simulations show that the maximum nodal throughput of the proposed MAC protocol increases by at least 20%and the access delay of the mobile node decreases by about 90%,compared to the two reference protocols.Besides,the average access probability of the mobile node in the proposed protocol is more than 90%.
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.
文摘无线传感器网络(WSNs)的运行效果对保证网络定位精度具有重要的意义。由于网络定位信息数据均可由自组网内节点随机获取,网络定位适用性在先验式路由协议链路状态路由协议(Optimized Link State Routing,OLSR)下表现更好。为了解决OLSR的多点中继(Multpoint Relays,MPR)节点运动速度较快的问题,为此设计了一种基于能量消耗的网络定位OLSR路由协议MPR机制评估方法,并开展仿真分析。研究结果表明:与原协议相比,节点能量消耗MPR选举生成协议表现出的性能更佳,经能量消耗MPR后形成的协议的吞吐量更大,有利于促进网络运行稳定性的提高。
文摘针对区块链边缘节点的部署环境开放、安全措施薄弱、易受到安全攻击,以及计算和网络资源不足等问题,提出一种基于可信执行环境(TEE)的区块链安全架构P-Dledger。该架构通过构建两阶段的信任链,在满足软件便捷迭代的基础上,确保加载部件的可信;通过实现智能合约可信执行框架以及基于串行外设接口或非门存储器(SPI NOR Flash)的数据可信存储,保证智能合约的可信计算与数据的可信存储;同时,为共识提案赋予单调递增的唯一标识,限制拜占庭节点的行为。实验与分析结果表明:所提架构确保了加载主体、账本数据与执行过程的安全可信;当网络延时大于60 ms或节点数大于8时,P-Dledger比采用拜占庭容错(PBFT)算法的区块链系统的吞吐量更高,且随着网络延时与节点数的增加,P-Dledger性能表现更稳定。
基金supported by the Fundamental Research Funds for the Central Universities under grant No.2009JBM007supported by the National Natural Science Foundation of China under Grants No. 60802016, 60833002 and 60972010
文摘A Light-Weight Simple Network Management Protocol (LW-SNMP) for the wireless sensor network is proposed, which is a kind of hierarchical network management system including a sink manager, cluster proxies, and node agents. Considering the resource limitations on the sensor nodes, we design new management messages, new data types and new management information base completely. The management messages between the cluster proxy and node agents are delivered as normal data packets. The experiment results show that LW-SNMP can meet the management demands in the resource-limited wireless sensor networks and has a good performance in stability, effectiveness of memory, extensibility than the traditional Simple Network Management Protocol (SNMP).
文摘The airspace communication network based on spacecraft has a wide range of applications in regional information enhancement and emergency communication. In this paper, a routing algorithm for congestion degree detection of multipath routing (CD_AOMDV) is proposed. The method of combining the whole congestion degree detection and local congestion degree detection before service initiation is adopted. Timely and accurate judgment of the congestion degree reduced the loss rate of the hot nodes, so the average packet loss rate reduced. Simulation results show that compared with the traditional AOMDV protocol, the CD_AOMDV proposed in this paper has reduced the packet loss and improved delay performance, which is more suitable for the airspace communication network.
文摘The performance of a Mobile Ad hoc Network (MANET) is closely related to the capability of the implemented routing protocol to adapt itself to unpredictable changes of topology network and link status. The Optimized Link State Routing (OLSR) protocol is a one key of the proactive routing protocols for MANETs. It is based on the multi-point relays (MPRs) technique to reach all nodes in the network with a limited number of broadcasts. In this paper, we propose new versions of the original OLSR protocol based on a new mobility parameter, in the goal to enhance and adapt it in the presence of the mobility. For this objective we define new three criterions for MPRs selection. The first criteria take for selection, just the mobility of nodes at one-hop. The two others criterions are based on both mobility of nodes at one-hop and two-hops.
文摘The application environments of wireless Ad hoc networks require that it should support Quality of Service (QoS). However, that is very difficult because of the inherent characteristics of the wireless channel and the frequent changes of network topology caused by nodes movement. An Ad hoc QoS Multicasting (AQM) protocol can solve this problem by previously reserving the neighbor nodes for tracking resource availability. By considering QoS restrictions of transport delay, loss ratio, bandwidth requirement, delay jitter, and throughout, and by finding the adaptive routing, the AQM protocol can obviously improve the efficiency of multicastsession. The results of network simulation show that QoS is essentially applicable to Ad hoc networks.
基金the National Natural Science Foundation of China under Grant 60372107.
文摘Energy efficiency is the primary issue for the Medium Access Control (MAC) protocol in sensor networks. Adopting periodic sleep,adaptive listen,overhearing avoidance and message passing mechanisms,the Sensor Medium Access Control (S-MAC) protocol improves energy efficiency and latency in the network. There are mainly two methods to enhance the S-MAC protocol: dynamic adjustment,and sending control and data packets under different transport conditions. For the wireless sensor network,it is not realistic to design one MAC protocol that meets all requirements of every aspect; however,it is possible to design corresponding protocols in accordance with different requirements by flexibly adopting different methods.
