一种适用于无线传感器网络的功率控制MAC协议

功率控制技术通过减少节点的发射功率来降低能耗,但节点间不对称的发射功率会增加网络的冲突概率并降低吞吐量.根据实际环境中的节点部署情况,引入了基于Pareto分布的系统模型.研究了传感器网络中功率控制技术在节省能量方面的性能,提出了一种基于SMAC(sensor-MAC)可适用于无线传感器网络的功率控制MAC(media access control)协议.此协议使用功率控制调度算法选择最优相邻节点,使网络中节点的拓扑连接得到优化,在保证网络连通性的同时,降低通信的冲突率,扩大网络的吞吐量.信息的传递以最优功率发射,并使通信节点具有反作用冲突节点的能力,从而在降低网络能耗的同时保证了节点间通信的公平性.实验仿真结果显示,与现有的几种重要方案相比,新的功率控制MAC协议使网络具有了更大的有效吞吐量及更长的生存时间.     

一种高效节能的PR-MAC协议

为解决无线传感器网络能耗过大和效率不高的问题,提出一种功率控制和多速率自适应的PR-MAC协议。该协议采用功率控制和多速率自适应技术,在降低能耗的同时提高网络的吞吐量。仿真实验结果表明,该协议采用基于节点剩余能量和距离基站跳数的随机退避策略可提高网络效率,在选择节点发送数据上考虑节点的剩余能量和距离基站跳数等因素,能有效地平衡无线传感器网络的能量。     

一种适用于Ad Hoc网络的多信道能量高效MAC协议

对多信道条件下MAC协议功率控制机制进行了分析,提出一种能够根据各个接收节点的通信状况,动态地调整数据信道上数据帧的传输功率和控制信道上CTS帧的发送功率的多信道Ad Hoc网络能量高效的MAC协议(MPEMAC).仿真表明,该协议有效的节省了节点能耗,延长了网络节点的生存时间,同时还能够增大空间信道的利用率,从而进一步提高网络的平均吞吐量.     

一种基于功率控制的无线传感器网络MAC协议

提出了一种基于功率控制的无线传感器网络MAC协议,根据节点接收阈值,计算出节点发送最优功率,在根本上减小发送功率从而节省节点能量。为了减少节点间的碰撞,引入了自适应调整竞争窗口和快速退避机制,减少节点空闲时间,从而进一步减少节点耗能。仿真结果显示在能量和吞吐量上都有显著提高。     

基于功率退避的MAC协议优化算法

针对多跳稠密的移动Ad hoc网络面临的网络生存时间、无线资源利用效率以及时延要求等问题,提出一种新的功率控制MAC协议,该协议在功率退避基础上结合改进的时间退避机制,采用较灵活的竞争窗口调节方法有效地缓解冲突。仿真结果表明,该协议可以减少移动节点消耗的功率,提高节点的能量利用效率和系统的吞吐量性能。     

能量有效的无线传感器网络MAC协议

针对无线传感器网络中的隐终端和延迟问题,提出一种基于功率控制机制的改进MAC协议。节点在SMAC协议的基础上通过功率控制算法在每个节点所保存的功率等级表中动态地选择合适的功率值作为其发射功率,从而避免了隐终端和延迟问题。仿真结果表明,与SMAC协议相比,改进协议能提高网络的吞吐量,降低源节点到目的节点的端到端延迟。     

用于传感网功率控制的并行传输MAC 协议

针对无线传感网（WSNs）中节点间不对称的发射功率引起的隐藏节点和暴露节点问题,提出一种用于传感网功率控制的MAC协议（MAC4PC）.该协议采用邻节点向量表对邻节点的状态及当前会话的信息进行记录,并设计了相关的控制帧收发时序和干扰度判断准则,以保证新建立会话与当前会话互不干涉,从而实现暴露节点的并行传输.仿真结果表明,与802.11 DCF协议、SB-FSMA/CA协议以及GLPCB-PMAC协议相比较,MAC4PC协议提高了网络平均吞吐量,降低了节点平均能耗和数据分组的平均传输时延.     

基于深度与可靠链路的水下无线传感器网络机会路由

在水下无线传感器网络中,传感节点带宽和能量受限阻碍了从移动节点至声纳浮标的数据传输。为此,提出新的水下无线传感器网络的机会路由协议。引入深度阈值提高吞吐量,减少跳数,利用深度阈值构建候选转发集,计算候选转发集内节点的路由指标,依据路由指标设置优先级,根据优先级设置定时器,并进行抑制冗余数据包数。实验结果表明,与基于压力感测协议相比,该协议能提高网络吞吐量,并降低能耗。     

联合空时需求预留和功率控制的MAC协议

提出了一种应用于移动Ad Hoc网络中的联合空时预留和功率控制MAC协议.它通过对信道时间和空间资源预留更为精确的估计优化了可用的信道资源,提高了信道的空间利用率,降低了碰撞冲突的概率.因为物理层头部采用最低的速率进行传输,把这种时空估计信息嵌在物理层帧头部,可以把信息传播到更多更远的邻节点,减少了碰撞的概率.同时结合功率控制技术对数据包传输功率进行控制,降低了节点的能量消耗.通过仿真与IEEE 802.11 MAC协议进行比较,该协议提高了系统的吞吐量,移动节点功率消耗明显降低,节点的能量利用效率得到提高.     

基于状态着色的水声网络 ＭＡＣ 协议

水声网络中的MAC协议主要采用RTS/CTS机制,然而RTS/CTS控制包不仅限制了并发传输的可能性进而降低了信道利用率和吞吐量,而且造成信道资源分配不公平。为了提高吞吐量、信道利用率和公平性,提出了一种基于状态着色的水声网络MAC协议（State Coloring based MAC, SC-MAC）。在SC-MAC协议中,每个节点根据自身一跳邻居表构建本地分层图,通过侦听数据帧或ACK帧获知邻居节点状态来为本地分层图中的节点着色,并根据本地分层着色图调度包的发送,减少数据帧的碰撞与重传。SC-MAC协议在避免冲突的前提下实现了并行传输。同时,给出基于公平性的退避方案以提高SC-MAC协议的公平性。仿真结果表明,SC-MAC协议与R-MAC协议和slotted-FAMA协议相比在端到端延迟、吞吐量和平均能耗等方面有明显的优势。     

基于马尔科夫链的LoRaWAN网络节点性能分析

低功耗广域网LoRaWAN(Long Range Wide Area Network)能兼顾低功耗与远通信距离,已经应用于很多领域。本文分析了LoRaWAN协议中A类节点发送数据的过程,据此建立了包含各个状态转移概率的马尔科夫模型。然后,基于SX1278芯片的相关参数对协议模型进行了仿真,并分析了LoRaWAN网络中网关回复时机、节点数量、频段数、链路质量等因素对A类节点发送数据的延时和能耗的影响。仿真结果表明,在单网关且总信道数不变的情况下,减少频段数,延后网关确认回复可以缩短节点发送数据的延时,降低节点发送数据的能耗。这对提升LoRaWAN网络性能具有很强的参考性。     

多个无线传感器网络中节能MAC协议设计

在无线传感器网络中,媒体访问控制(MAC)层协议影响着整个网络的性能。根据无线传感器网络对节点能耗和时延的要求,本文提出了一种基于跨层设计的节能MAC协议。利用物理层、MAC层和路由层之间的信息交互,在保证可靠通信的基础上,实现在一个监听/睡眠周期内数据多跳传输,缩短数据传输时延,并且有效控制网络数据传输的冗余度,降低冗余节点能量消耗。性能分析和仿真结果表明,节能MAC协议能够有效地降低网络时延并且减少节点能耗。     

基于最小节点度的WSNs传输功率控制重编程协议

为了降低节点能耗,提高能量的利用率,提出了一种高效节能的基于最小节点度的传输功率控制(MND—TPC)重编程协议。该协议首先根据每个节点的剩余能量、最大的传输功率、节点度和链路质量来进行网络的初始化,然后分2个阶段完成数据传输。第一阶段通过节点密度、节点度和M度节点的百分比等产生传输范围的调整模型来构建高效的优化网络;第二阶段通过对节点之间发送功率和剩余能量的比较来筛选发送节点,以保证网络负载的均匀分布,有效地实现了高效节能,从而提高整个网络的生存周期。理论分析与实验结果表明:与多跳网络编程(MNP)协议在不同发送功率下相比,平均能量消耗至少降低35.48%。     

Adaptive listen for energy-efficient medium access control in wireless sensor networks

Wireless Sensor Networks (WSN) have nodes that are small in size and are powered by small batteries having very limited amount of energy. In most applications of WSN, the nodes in the network remain inactive for long periods of time, and intermittently they become active on sensing any change in the environment. The data sensed by the different nodes are sent to the sink node. In contrast to other infrastructure-based wireless networks, higher throughput, lower latency and per-node fairness in WSN are imperative, but their importance is subdued when compared to energy consumption. In this work, we have regarded the amount of energy consumption in the nodes to be of primary concern, while throughput and latency in the network to be secondary. We have proposed a protocol for energy-efficient adaptive listen for medium access control in WSN. Our protocol adaptively changes the slot-time, which is the time of each slot in the contention window. This correspondingly changes the cycle-time, which is the sum of the listen-time and the sleep-time of the sensors, while keeping the duty-cycle, which is the ratio between the listen-time and the cycle-time, constant. Using simulation experiments, we evaluated the performance of the proposed protocol, compared with the popular Sensor Medium Access Control (SMAC) (Ye et al. IEEE/ACM Trans Netw 12(3):493–506, 39) protocol. The results we obtained show a prominent decrease in the energy consumption at the nodes in the proposed protocol over the existing SMAC protocol, at the cost of decreasing the throughput and increasing the latency in the network. Although such an observation is not perfectly what is ideally desired, given the very limited amount of energy with which the nodes in a WSN operate, we advocate that increasing the energy efficiency of the nodes, thereby increasing the network lifetime in WSN, is a more important concern compared to throughput and latency. Additionally, similar observations relating energy efficiency, network lifetime, throughput and latency exist in many other existing protocols, including the popular SMAC protocol (Ye et al. IEEE/ACM Trans Netw 12(3):493–506, 39).     

Modern architecture for photonic networks-on-chip

Development in photonic integrated circuits (PICs) provides a promising solution for on-chip optical computation and communication. PICs provides the best alternative to traditional networks-on-chip (NoC) circuits which face serious challenges such as bandwidth, latency and power consumption. Integrated optics have substantiated the ability to accomplish low-power communication and low-power data processing at ultra-high speeds. In this work, we propose a new architecture for NoC, which might improve overall on-chip network performance by reducing its power consumption, providing large channel capacity for communication, decreasing latency among nodes and reducing hop count. Some of the key features of the proposed architecture are to reduce the waveguide network for communication among nodes, and this architecture can be used as a brick to construct other architectures. In this architecture, we use micro-ring resonator (MRR) and it is used to provide a high bandwidth connection among nodes with a lesser number of waveguide networks. Furthermore, results show that this architecture of PICs provides better performance in terms of low communication latency, low power consumption, high bandwidth. It also provides acceptable FSR value, FWHR value, finesse value and Q-factor of micro-ring resonators used for the design of MRR in this architecture.

     

An adaptive polling interval and short preamble media access control protocol for wireless sensor networks

Media access control (MAC) protocols control how nodes access a shared wireless channel. It is critical to the performance of wireless sensor networks (WSN). An adaptive polling interval and short preamble MAC protocol (AX-MAC) is proposed in this paper. AXMAC is an asynchronous protocol which composed of two basic features. First, rendezvous between the sender and the receiver is reached by a series of short preambles. Second, nodes dynamically adjust their polling intervals according to network traffic conditions. Threshold parameters used to determine traffic conditions and adjust polling intervals are analyzed based on a Markov chain. Energy consumption and network latency are also discussed in detail. Simulation results indicate that AXMAC is suited to dynamic network traffic conditions and is superior to both X-MAC and Boost-MAC in energy consumption and latency.     

带冲突避免和流量自适应的低功耗侦听MAC协议

为提升无线传感器网络在能耗、时延以及动态适应负载方面的综合性能, 对几种典型MAC协议进行了分析, 提出了一种带冲突避免和流量自适应的LCT-MAC协议。在该协议中, 长前导码被划分为多个小前导码, 并嵌入目的节点地址信息, 避免了串音; 节点可以根据网络流量调整睡眠周期, 减少了时延; 在重负载时, 节点能基于优先级信息选择退避时长, 避免冲突。仿真结果表明, 与S-MAC协议和LPL协议相比, LCT-MAC协议降低了传输时延, 并减少了全网能耗和数据包碰撞次数, 具有优良的综合性能。     

Balancing the power consumption speed in flat and hierarchical WSN

A combination of a cluster tree routing protocol and an Ad hoc on demand vector (AODV) routing protocol is used in the latest ZigBee standard wireless sensor networks (WSNs) technology. However, the AODV routing protocol has no means by which to take into consideration the power consumption of the nodes during the routing process. Therefore, a new approach is proposed in this paper to balance the power consumption speed and to distribute the responsibilities of routing among fiat wireless sensor nodes and the three levels of hierarchical wireless sensor nodes. These three levels are based on the three types of devices, which are used in the ZigBee standard: the coordinator, the touters, and the end devices. In this paper, we have compared the original AODV routing protocol with our extension approach for the distribution of power consumption. Based on the simulation results, our new approach has achieved better performance in terms of increasing the lifetime of the fiat wireless sensor network, the personal area network (PAN)coordinator, the touters, and the whole network of the hierarchical wireless sensor network. Additionally, it has better performance in terms of distributing the power consumption among the key nodes of the wireless sensor network.     

面向特定区域的WSN组播路由协议

针对无线传感器网络(WSN)中节点分布不均和能量消耗较大的问题,提出一种面向特定区域的WSN组播路由协议.采用组头轮换机制,使能量储备较多和位置最优的节点担任组播节点承担转发任务,能量储备较少的节点负责数据采集任务.利用多转发组的模式建立稳定路由,提高网络健壮性,降低数据延迟.仿真结果表明,该协议可使整个区域内节点能量...