In wireless ad hoc networks, nodes cooperatively form a network without any infrastructure such as a BS/AP (base station or access point). The widely-used contention-based MAC protocol, IEEE 802.11b, is inefficient in...In wireless ad hoc networks, nodes cooperatively form a network without any infrastructure such as a BS/AP (base station or access point). The widely-used contention-based MAC protocol, IEEE 802.11b, is inefficient in multi-hop networks due to the hidden and exposed terminal problems. The most popular schedule-based MAC protocol, TDMA (time division multiple access), is difficult to implement in an ad hoc network due to the lack of infrastructure. The contribution of this paper is to provide the community novel and efficient MAC (medium access control) protocols (i.e., a collision resolution protocol) for a wireless ad hoc network without a centralized infrastructure. We propose two new MAC protocols (one distributed algorithm and one cluster-based algorithm) that use a collision resolution scheme for a network with a single BS/AP. We first compare the performance of our distributed algorithm with our cluster-based algorithm. Then, we compare our algorithm that performs better (i.e., our cluster-based algorithm) to TDMA in a two-hop network. The simulation results illustrate that our cluster-based algorithm provides higher throughput and lower delay than TDMA in a two-hop network.展开更多
车载网VANET是一种应用于智能交通系统的新型无线移动自组织网络(mobile ad hoc network,MANET).随着车辆以及移动ad hoc网络技术的发展,车载网已经成为一个新兴的研究领域.针对VANET中车辆行驶的特征,提出一种拓扑相对稳定的车辆分簇算...车载网VANET是一种应用于智能交通系统的新型无线移动自组织网络(mobile ad hoc network,MANET).随着车辆以及移动ad hoc网络技术的发展,车载网已经成为一个新兴的研究领域.针对VANET中车辆行驶的特征,提出一种拓扑相对稳定的车辆分簇算法.在此算法基础上,根据专用短程通信(dedicated short range communication,DSRC)标准中控制信道(control channel,CCH)和服务信道(service channel,SCH)的分配,考虑车辆间的无线通信干扰和不同应用的QoS需求,提出一种基于分簇的多信道混合型MAC协议,簇内通信采用非竞争的TDMA机制,簇间通信采用基于竞争的CSMA?CA机制,相邻簇采用不同的服务信道.模拟实验表明,提出的MAC协议在同时满足实时应用的延迟需求和非实时应用的吞吐量方面,优于现有协议.展开更多
传感器节点沿树状多跳路径逐级向Sink转发数据是无线传感器网络的主要业务模式之一。针对此类业务,该文的EBRI-MAC(Energy-efficient MAC protocol Based on Routing Information)协议提出一种对应树状路由转发关系,由父节点与子节点构...传感器节点沿树状多跳路径逐级向Sink转发数据是无线传感器网络的主要业务模式之一。针对此类业务,该文的EBRI-MAC(Energy-efficient MAC protocol Based on Routing Information)协议提出一种对应树状路由转发关系,由父节点与子节点构成虚拟群的思想;并设计了连锁邀请与CSMA/CA结合的信道接入机制以及基于虚拟群同步的周期休眠机制,以达到节能的目的。结合节点能耗因素,定义了能量有效性的性能参数,并对EBRI-MAC的能量有效性进行理论分析。通过ns-2仿真结果表明网络业务时间相关性较强时,EBRI-MAC的能量有效性优于IEEE802.11DCF和S-MAC。展开更多
针对组网导航系统(networked navigation systems,NNSs)中节点高速移动、能量受限及通信时滞的问题,融合了基于移动汇聚节点的交叉路由树构建及链式分簇相结合的路由协议(cross routing tree construction based on mobile sink and cha...针对组网导航系统(networked navigation systems,NNSs)中节点高速移动、能量受限及通信时滞的问题,融合了基于移动汇聚节点的交叉路由树构建及链式分簇相结合的路由协议(cross routing tree construction based on mobile sink and chain clustering,CRTCC),设计了一种基于节点分级的跨层媒介访问控制协议(medium access control protocol based on graded nodes,GN-MAC)。GN-MAC采取了基于竞争的媒介访问方式,结合CRTCC协议特点定义GN-MAC包格式并完成具有多级别节点的自适应虚拟分簇,同时设计了改进型节点移动性检测算法,作出了最优簇间切换决策,提出了基于优先级的竞争机制以及多信道通信机制。最后通过算例仿真,验证了GN-MAC在节点高速移动和多移动节点情况下,时滞和能耗得到了有效的控制。展开更多
文摘In wireless ad hoc networks, nodes cooperatively form a network without any infrastructure such as a BS/AP (base station or access point). The widely-used contention-based MAC protocol, IEEE 802.11b, is inefficient in multi-hop networks due to the hidden and exposed terminal problems. The most popular schedule-based MAC protocol, TDMA (time division multiple access), is difficult to implement in an ad hoc network due to the lack of infrastructure. The contribution of this paper is to provide the community novel and efficient MAC (medium access control) protocols (i.e., a collision resolution protocol) for a wireless ad hoc network without a centralized infrastructure. We propose two new MAC protocols (one distributed algorithm and one cluster-based algorithm) that use a collision resolution scheme for a network with a single BS/AP. We first compare the performance of our distributed algorithm with our cluster-based algorithm. Then, we compare our algorithm that performs better (i.e., our cluster-based algorithm) to TDMA in a two-hop network. The simulation results illustrate that our cluster-based algorithm provides higher throughput and lower delay than TDMA in a two-hop network.
文摘车载网VANET是一种应用于智能交通系统的新型无线移动自组织网络(mobile ad hoc network,MANET).随着车辆以及移动ad hoc网络技术的发展,车载网已经成为一个新兴的研究领域.针对VANET中车辆行驶的特征,提出一种拓扑相对稳定的车辆分簇算法.在此算法基础上,根据专用短程通信(dedicated short range communication,DSRC)标准中控制信道(control channel,CCH)和服务信道(service channel,SCH)的分配,考虑车辆间的无线通信干扰和不同应用的QoS需求,提出一种基于分簇的多信道混合型MAC协议,簇内通信采用非竞争的TDMA机制,簇间通信采用基于竞争的CSMA?CA机制,相邻簇采用不同的服务信道.模拟实验表明,提出的MAC协议在同时满足实时应用的延迟需求和非实时应用的吞吐量方面,优于现有协议.
文摘传感器节点沿树状多跳路径逐级向Sink转发数据是无线传感器网络的主要业务模式之一。针对此类业务,该文的EBRI-MAC(Energy-efficient MAC protocol Based on Routing Information)协议提出一种对应树状路由转发关系,由父节点与子节点构成虚拟群的思想;并设计了连锁邀请与CSMA/CA结合的信道接入机制以及基于虚拟群同步的周期休眠机制,以达到节能的目的。结合节点能耗因素,定义了能量有效性的性能参数,并对EBRI-MAC的能量有效性进行理论分析。通过ns-2仿真结果表明网络业务时间相关性较强时,EBRI-MAC的能量有效性优于IEEE802.11DCF和S-MAC。
文摘针对组网导航系统(networked navigation systems,NNSs)中节点高速移动、能量受限及通信时滞的问题,融合了基于移动汇聚节点的交叉路由树构建及链式分簇相结合的路由协议(cross routing tree construction based on mobile sink and chain clustering,CRTCC),设计了一种基于节点分级的跨层媒介访问控制协议(medium access control protocol based on graded nodes,GN-MAC)。GN-MAC采取了基于竞争的媒介访问方式,结合CRTCC协议特点定义GN-MAC包格式并完成具有多级别节点的自适应虚拟分簇,同时设计了改进型节点移动性检测算法,作出了最优簇间切换决策,提出了基于优先级的竞争机制以及多信道通信机制。最后通过算例仿真,验证了GN-MAC在节点高速移动和多移动节点情况下,时滞和能耗得到了有效的控制。
