Hybrid Power-line/Visible-light Communication(HPVC)network has been one of the most promising Cooperative Communication(CC)technologies for constructing Smart Home due to its superior communication reliability and har...Hybrid Power-line/Visible-light Communication(HPVC)network has been one of the most promising Cooperative Communication(CC)technologies for constructing Smart Home due to its superior communication reliability and hardware efficiency.Current research on HPVC networks focuses on the performance analysis and optimization of the Physical(PHY)layer,where the Power Line Communication(PLC)component only serves as the backbone to provide power to light Emitting Diode(LED)devices.So designing a Media Access Control(MAC)protocol remains a great challenge because it allows both PLC and Visible Light Communication(VLC)components to operate data transmission,i.e.,to achieve a true HPVC network CC.To solve this problem,we propose a new HPC network MAC protocol(HPVC MAC)based on Carrier Sense Multiple Access/Collision Avoidance(CSMA/CA)by combining IEEE 802.15.7 and IEEE 1901 standards.Firstly,we add an Additional Assistance(AA)layer to provide the channel selection strategies for sensor stations,so that they can complete data transmission on the selected channel via the specified CSMA/CA mechanism,respectively.Based on this,we give a detailed working principle of the HPVC MAC,followed by the construction of a joint analytical model for mathematicalmathematical validation of the HPVC MAC.In the modeling process,the impacts of PHY layer settings(including channel fading types and additive noise feature),CSMA/CA mechanisms of 802.15.7 and 1901,and practical configurations(such as traffic rate,transit buffer size)are comprehensively taken into consideration.Moreover,we prove the proposed analytical model has the solvability.Finally,through extensive simulations,we characterize the HPVC MAC performance under different system parameters and verify the correctness of the corresponding analytical model with an average error rate of 4.62%between the simulation and analytical results.展开更多
IEEE 802.15.4 protocol is proposed to meet the low latency and energy consumption needs in low-rate wireless applications, however, few analytical models are tractable enough for comprehensive evaluation of the protoc...IEEE 802.15.4 protocol is proposed to meet the low latency and energy consumption needs in low-rate wireless applications, however, few analytical models are tractable enough for comprehensive evaluation of the protocol. To evaluate the IEEE 802.15.4 slotted CSMA/CA channel access mechanism in this paper, we propose a practical and accurate discrete Markov chain model, which can dynamically represent different network loads. By computing the steady-state distribution probability of the Markov chain, we obtain an evaluation formula for throughput, energy consumption, and access latency. Then we further analyze the parameters that influence performance including packet arrival rate, initial backoff exponent and maximum backoff number. Finally, NS2 simulator has been used to evaluate the performance of the 802.15.4 CSMA/CA mechanism under different scenarios and to validate the accuracy of the proposed model.展开更多
我国电力工业迅速发展,智能电网规模不断扩大,需要在线监控的设备和对象也越来越多,传统的监控与数据采集(Supervisory Control And Data Acquisition,SCADA)系统已无法满足电力信息化的要求。文章将ZigBee技术应用于SCADA的数据采集系...我国电力工业迅速发展,智能电网规模不断扩大,需要在线监控的设备和对象也越来越多,传统的监控与数据采集(Supervisory Control And Data Acquisition,SCADA)系统已无法满足电力信息化的要求。文章将ZigBee技术应用于SCADA的数据采集系统,针对系统节点业务不断变化对网络性能的影响,提出了一种网络负荷判断和最小二乘线性拟合的退避策略。在每次载波监听多路访问/冲突避免(Carrier Sense Multiple Access with Collision Avoidance,CSMA/CA)开始时,根据上一时刻的网络负荷和数据包是否发送成功预测下一时刻的网络负荷,并用最小线性拟合法实时调整退避指数。仿真结果表明,与IEEE802.15.4标准协议算法比较,该算法提高了网络吞吐量,减小了数据包的丢包率,同时还降低了能耗。展开更多
针对IEEE 802.15.4MAC协议中的标准时隙CSMA/CA(carrier sense multiple access with collision avoidance)机制不能提供数据流区分服务的问题,提出了一种基于优先级的网络负载动态自适应参数调整DAPA-CSMA/CA算法.该算法根据应用实时...针对IEEE 802.15.4MAC协议中的标准时隙CSMA/CA(carrier sense multiple access with collision avoidance)机制不能提供数据流区分服务的问题,提出了一种基于优先级的网络负载动态自适应参数调整DAPA-CSMA/CA算法.该算法根据应用实时性的需求为不同的节点分配不同的优先级,优化协议参数配置以实现区分服务,并通过动态调整退避指数来自适应网络流量变化,在此基础上,结合马尔可夫原理对DAPA-CSMA/CA算法的信道竞争过程进行理论分析.仿真结果表明:该算法具有较强的网络自适应能力,可以降低节点间的碰撞,降低丢包率、时延及能耗,更好地满足无线传感器网络在实时监测环境中对高服务质量的要求.展开更多
To reach necessary end-to-end connectivity between the Internet and wireless sensor networks （WSNs）, the Internet Engineering Task Force （IETF） IPv6 over low power wireless personal area network （6LowPAN） workin...To reach necessary end-to-end connectivity between the Internet and wireless sensor networks （WSNs）, the Internet Engineering Task Force （IETF） IPv6 over low power wireless personal area network （6LowPAN） working group has been established and introduced an adaptation layer for integration of IEEE 802.15.4 physical layer/media access control （PHY/MAC） layers and the upper layers of any Intemet protocol （IP）-based networks, such as the Internet. The energy efficiency is one of the most important performance measures in WSNs because most sensor nodes are only battery powered so we should reduce the energy consumption to the lowest to extend the life of nodes. Therefore the determination of MAC frame length should be carefully considered since that the radio frequency （RF） module consumes most the energy of a sensor node meanwhile the MAC protocol is the direct controller of RF module. In this paper, we provide a star-shaped 6LowPAN non-beacon mode with unslotted carrier sense multiple access with collision avoidance （CSMA/CA） mechanism to access to the channel and model the stochastic behavior of a target end node as the M/G/1 queuing system. Analytical expressions for some parameters such as channel busy probability, packet loss probability and energy efficiency are obtained in this paper and our analytical results can clearly show the impact of MAC frame length on the energy efficiency of a target node in both ideal and lossy channel.展开更多
基金supported by the National Natural Science Foundation of China(No.61772386)National Key Research and Development Project(No.2018YFB1305001)Fundamental Research Funds for the Central Universities(No.KJ02072021-0119).
文摘Hybrid Power-line/Visible-light Communication(HPVC)network has been one of the most promising Cooperative Communication(CC)technologies for constructing Smart Home due to its superior communication reliability and hardware efficiency.Current research on HPVC networks focuses on the performance analysis and optimization of the Physical(PHY)layer,where the Power Line Communication(PLC)component only serves as the backbone to provide power to light Emitting Diode(LED)devices.So designing a Media Access Control(MAC)protocol remains a great challenge because it allows both PLC and Visible Light Communication(VLC)components to operate data transmission,i.e.,to achieve a true HPVC network CC.To solve this problem,we propose a new HPC network MAC protocol(HPVC MAC)based on Carrier Sense Multiple Access/Collision Avoidance(CSMA/CA)by combining IEEE 802.15.7 and IEEE 1901 standards.Firstly,we add an Additional Assistance(AA)layer to provide the channel selection strategies for sensor stations,so that they can complete data transmission on the selected channel via the specified CSMA/CA mechanism,respectively.Based on this,we give a detailed working principle of the HPVC MAC,followed by the construction of a joint analytical model for mathematicalmathematical validation of the HPVC MAC.In the modeling process,the impacts of PHY layer settings(including channel fading types and additive noise feature),CSMA/CA mechanisms of 802.15.7 and 1901,and practical configurations(such as traffic rate,transit buffer size)are comprehensively taken into consideration.Moreover,we prove the proposed analytical model has the solvability.Finally,through extensive simulations,we characterize the HPVC MAC performance under different system parameters and verify the correctness of the corresponding analytical model with an average error rate of 4.62%between the simulation and analytical results.
基金National Basic Research 973 Program of China under Grant No.2006CB303000the National Natural Science Foundation of China under Grant Nos.60673187,60702009,and 60872055
文摘IEEE 802.15.4 protocol is proposed to meet the low latency and energy consumption needs in low-rate wireless applications, however, few analytical models are tractable enough for comprehensive evaluation of the protocol. To evaluate the IEEE 802.15.4 slotted CSMA/CA channel access mechanism in this paper, we propose a practical and accurate discrete Markov chain model, which can dynamically represent different network loads. By computing the steady-state distribution probability of the Markov chain, we obtain an evaluation formula for throughput, energy consumption, and access latency. Then we further analyze the parameters that influence performance including packet arrival rate, initial backoff exponent and maximum backoff number. Finally, NS2 simulator has been used to evaluate the performance of the 802.15.4 CSMA/CA mechanism under different scenarios and to validate the accuracy of the proposed model.
文摘我国电力工业迅速发展,智能电网规模不断扩大,需要在线监控的设备和对象也越来越多,传统的监控与数据采集(Supervisory Control And Data Acquisition,SCADA)系统已无法满足电力信息化的要求。文章将ZigBee技术应用于SCADA的数据采集系统,针对系统节点业务不断变化对网络性能的影响,提出了一种网络负荷判断和最小二乘线性拟合的退避策略。在每次载波监听多路访问/冲突避免(Carrier Sense Multiple Access with Collision Avoidance,CSMA/CA)开始时,根据上一时刻的网络负荷和数据包是否发送成功预测下一时刻的网络负荷,并用最小线性拟合法实时调整退避指数。仿真结果表明,与IEEE802.15.4标准协议算法比较,该算法提高了网络吞吐量,减小了数据包的丢包率,同时还降低了能耗。
文摘针对IEEE 802.15.4MAC协议中的标准时隙CSMA/CA(carrier sense multiple access with collision avoidance)机制不能提供数据流区分服务的问题,提出了一种基于优先级的网络负载动态自适应参数调整DAPA-CSMA/CA算法.该算法根据应用实时性的需求为不同的节点分配不同的优先级,优化协议参数配置以实现区分服务,并通过动态调整退避指数来自适应网络流量变化,在此基础上,结合马尔可夫原理对DAPA-CSMA/CA算法的信道竞争过程进行理论分析.仿真结果表明:该算法具有较强的网络自适应能力,可以降低节点间的碰撞,降低丢包率、时延及能耗,更好地满足无线传感器网络在实时监测环境中对高服务质量的要求.
基金Supported by the National Natural Science Foundation of China (61071090, 61171093)the National Science and Technology Major Projects (2011ZX03005-004-003)the Innovation Project of SCI and Tech for College Graduates of Jiangsu Province (CXLX12_0475)
文摘To reach necessary end-to-end connectivity between the Internet and wireless sensor networks （WSNs）, the Internet Engineering Task Force （IETF） IPv6 over low power wireless personal area network （6LowPAN） working group has been established and introduced an adaptation layer for integration of IEEE 802.15.4 physical layer/media access control （PHY/MAC） layers and the upper layers of any Intemet protocol （IP）-based networks, such as the Internet. The energy efficiency is one of the most important performance measures in WSNs because most sensor nodes are only battery powered so we should reduce the energy consumption to the lowest to extend the life of nodes. Therefore the determination of MAC frame length should be carefully considered since that the radio frequency （RF） module consumes most the energy of a sensor node meanwhile the MAC protocol is the direct controller of RF module. In this paper, we provide a star-shaped 6LowPAN non-beacon mode with unslotted carrier sense multiple access with collision avoidance （CSMA/CA） mechanism to access to the channel and model the stochastic behavior of a target end node as the M/G/1 queuing system. Analytical expressions for some parameters such as channel busy probability, packet loss probability and energy efficiency are obtained in this paper and our analytical results can clearly show the impact of MAC frame length on the energy efficiency of a target node in both ideal and lossy channel.
