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1.
Wei Fang Mao Walaa Hamouda Iyad Dayoub 《Wireless Communications and Mobile Computing》2012,12(7):652-660
In this paper, we investigate the performance of a cross‐layer (physical and MAC) design for multiple‐input multiple‐output (MIMO) system that aims at maximizing the throughput of ad hoc networks by selecting the optimum antenna combination. Employing this cross‐layer design is shown to improve the overall network performance relative to the case where no antenna selection (AS) is used. To solve the node blocking problem associated with the IEEE 802.11 medium‐access control (MAC) protocol, the proposed protocol leverage the available degrees of freedom offered by the MIMO system to allow neighboring nodes to simultaneously communicate using the zero‐forcing (ZF) Bell‐labs layered space‐time (BLAST) architecture. Using the cross‐layer design, neighboring nodes share their optimum antenna selection (AS) information through control messages. Given this shared information, nodes set their decisions on the number of selected antennas based on the available spatial channels that guarantees collision‐free transmissions. At the destination node, the ZF receiver is employed to extract the desired user data while treating the data from neighboring users as interference. The performance of the proposed cross‐layer design is examined through simulations, where we show that the network throughput is significantly improved compared to conventional MAC protocols. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
2.
Melike Yigit H. Ugur Yildiz Sinan Kurt Bulent Tavli V. Cagri Gungor 《International Journal of Communication Systems》2018,31(11)
Packet size optimization is a critical issue in wireless sensor networks (WSNs) for improving many performance metrics (eg, network lifetime, delay, throughput, and reliability). In WSNs, longer packets may experience higher loss rates due to harsh channel conditions. On the other hand, shorter packets may suffer from greater overhead. Hence, the optimal packet size must be chosen to enhance various performance metrics of WSNs. To this end, many approaches have been proposed to determine the optimum packet size in WSNs. In the literature, packet size optimization studies focus on a specific application or deployment environment. However, there is no comprehensive and recent survey paper that categorizes these different approaches. To address this need, in this paper, recent studies and techniques on data packet size optimization for terrestrial WSNs, underwater WSNs, wireless underground sensor networks, and body area sensor networks are reviewed to motivate the research community to further investigate this promising research area. The main objective of this paper is to provide a better understanding of different packet size optimization approaches used in different types of sensor networks and applications as well as introduce open research issues and challenges in this area. 相似文献
3.
This paper presents a study of a cross‐layer design through joint optimization of spectrum allocation and power control for cognitive radio networks (CRNs). The spectrum of interest is divided into independent channels licensed to a set of primary users (PUs). The secondary users are activated only if the transmissions do not cause excessive interference to PUs. In particular, this paper studies the downlink channel assignment and power control in a CRN with the coexistence of PUs and secondary users. The objective was to maximize the total throughput of a CRN. A mathematical model is presented and subsequently formulated as a binary integer programming problem, which belongs to the class of non‐deterministic polynomial‐time hard problems. Subsequently, we develop a distributed algorithm to obtain sub‐optimal results with lower computational complexity. The distributed algorithm iteratively improves the network throughput, which consists of several modules including maximum power calculation, excluded channel sets recording, base station throughput estimation, base station sorting, and channel usage implementation. Through investigating the impacts of the different parameters, simulation results demonstrates that the distributed algorithm can achieve a better performance than two other schemes. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
4.
Sasan Khoshroo Honggang Wang Liudong Xing Dayalan Kasilingam 《Wireless Communications and Mobile Computing》2015,15(2):389-400
Wireless sensor networks (WSNs) have found a wide variety of applications recently. However, the challenges in WSNs still remain in improving the sensor energy efficiency and information quality (distortion reduction) of the sensing data transmissions. In this paper, we propose a novel cross‐layer design of resource allocation and channel coding to protect distributed source coding (DSC)‐based data transmission. Resource allocation strategies include rate adaptation and automatic repeat‐request retransmissions. Our proposed joint design of resource allocation, channel coding, and DSC can improve the network energy efficiency and information quality while meeting the data transmission latency requirements. Further, we investigate how the resource allocation enables the network to achieve unequal error protection among correlated DSC streams. Our simulation studies demonstrate that the proposed joint design significantly improves the DSC‐based data transmission quality and the network energy efficiency. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
5.
Dzmitry Kliazovich Simone Redana Fabrizio Granelli 《International Journal of Communication Systems》2012,25(4):461-477
Wireless networks are being increasingly employed to provide mobile access to network services. In most existing standards, reliable transmission on the wireless medium is achieved through the introduction of ARQ schemes at MAC layer, a strategy which is also employed by TCP for reliable end‐to‐end data delivery. The paper proposes an approach to overcome the performance degradation deriving from the duplicate ARQ strategies implemented at the transport and MAC layers by introducing a cross‐layer solution to reduce un‐necessary transmissions on the wireless medium. Furthermore, the paper describes how the proposed scheme, called ARQ Proxy, can be deployed in three different wireless technologies (3G Long‐Term Evolution, Wi‐Fi, and WiMAX) and provides extensive validation of the achievable improvement through simulations. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
6.
文章研究了无线传感器网络中协作自动请求重传（Cooperative Automatic Repeat Request, CARQ）协议的能量效率及其优化问题。定义协议的能量效率为单位能耗所支持的分组成功传输的个数,导出了CARQ协议和传统ARQ协议的能量效率表达式以及CARQ协议相对ARQ协议的能效增益表达式,依此对两协议的能量效率进行了仿真研究,发现协作节点的位置对协议的能量效率有重要影响,当通信距离大于“门限距离”时,CARQ协议的能量效率才高于传统ARQ协议能效;进而提出了一种离散优化算法,通过优化调制水平,大大提高了CARQ协议的能效及能效增益。 相似文献
7.
Qiong Shi Cristina Comaniciu Dandan Wang Ufuk Tureli 《International Journal of Communication Systems》2011,24(7):872-888
In this paper, we propose an optimization of MAC protocol design for wireless sensor networks, that accounts for cross‐layering information, in terms of location accuracy for nodes and residual energy levels. In our proposed solution we encode this cross‐layer information within a decreasing backoff function in the MAC. The protocol is optimized by appropriately selecting priority window lengths, and we have shown that accurate cross‐layer information plays a crucial role in achieving an optimal performance at the MAC layer level. The estimation accuracy can be characterized spatially using a location reliability probability distribution function. We show that this distribution function greatly influences the design of the optimal backoff window parameters, and the overall throughput performance of the MAC protocol. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
8.
随着无线通信的日益发展，无线自组织网络正逐渐从军用扩大到民用等诸多领域。但是无线自组织网络一般由电池供电，由于提高电池容量的技术进步缓慢，功率控制是一个重要的研究课题。无线自组织网络中的功率控制机制研究主要集中在3个方面，即网络层功率控制、链路层功率控制以及混合功率控制。重点是从分层的角度对功率控制进行阐述，主要介绍了网络层及链路层的功率控制，并介绍了一些节能协议。跨层设计综合考虑了各层性能能更好地为功率控制与节能服务。 相似文献
9.
Deng Liao Ahmed K. Elhakeem 《Transactions on Emerging Telecommunications Technologies》2012,23(1):6-15
A cross‐layer joint optimization approach is proposed for multihop routing in time‐division duplex code‐division multiple‐access wireless mesh networks. Two timeslot scheduling schemes are investigated for time‐division duplex operations. The routing at the network layer, the packet delay at the medium access control layer, and the signal‐to‐interference‐plus‐noise ratio at the physical layer are jointly optimized in a cross‐layer manner. The results show that the proposed cross‐layer optimization algorithm significantly outperforms the shortest‐path routing algorithm with respect to overall network performance. The maximum throughput of the whole mesh network can be optimized by jointly taking into account the end‐to‐end delay and successful packet rate. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
10.
Kuan‐Lin Chiu Yuh‐Shyan Chen Ren‐Hung Hwang 《International Journal of Communication Systems》2011,24(6):789-809
The next generation wireless communication system will likely be heterogeneous networks, as various technologies can be integrated on heterogeneous networks. A mobile multiple‐mode device can easily access the Internet through different wireless interfaces. The mobile multiple‐mode device thus could switch to different access points to maintain the robustness of the connection when it can acquire more resources from other heterogeneous wireless networks. The mobile multiple‐mode device therefore needs to face the handover problem in such environment. This work introduces Session Initiation Protocol (SIP)‐based cross‐layer scheme to support seamless handover scheme over heterogeneous networks. The proposed scheme consists of a battery lifetime‐based handover policy and cross‐layer fast handover scheme, called the SIP‐based mobile stream control transmission protocol (SmSCTP). This work describes the major idea of the proposed scheme and infrastructure. The proposed scheme has been implemented in Linux system. The simulation and numerical results demonstrate that the proposed SmSCTP scheme yields better signaling cost, hand‐off delay time, packet loss and delay jitter than SIP and mSCTP protocols. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
11.
Guangjie Han Yuhui Dong Hui Guo Lei Shu Dapeng Wu 《Wireless Communications and Mobile Computing》2015,15(16):1957-1981
In this paper, we propose a cross‐layer optimized geographic node‐disjoint multipath routing algorithm, that is, two‐phase geographic greedy forwarding plus. To optimize the system as a whole, our algorithm is designed on the basis of multiple layers' interactions, taking into account the following. First is the physical layer, where sensor nodes are developed to scavenge the energy from environment, that is, node rechargeable operation (a kind of idle charging process to nodes). Each node can adjust its transmission power depending on its current energy level (the main object for nodes with energy harvesting is to avoid the routing hole when implementing the routing algorithm). Second is the sleep scheduling layer, where an energy‐balanced sleep scheduling scheme, that is, duty cycle (a kind of node sleep schedule that aims at putting the idle listening nodes in the network into sleep state such that the nodes will be awake only when they are needed), and energy‐consumption‐based connected k‐neighborhood is applied to allow sensor nodes to have enough time to recharge energy, which takes nodes' current energy level as the parameter to dynamically schedule nodes to be active or asleep. Third is the routing layer, in which a forwarding node chooses the next‐hop node based on 2‐hop neighbor information rather than 1‐hop. Performance of two‐phase geographic greedy forwarding plus algorithm is evaluated under three different forwarding policies, to meet different application requirements. Our extensive simulations show that by cross‐layer optimization, more shorter paths are found, resulting in shorter average path length, yet without causing much energy consumption. On top of these, a considerable increase of the network sleep rate is achieved. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
12.
Mari Carmen Domingo 《ETRI Journal》2011,33(3):299-309
Energy consumption is a key issue in body sensor networks (BSNs) since energy‐constrained sensors monitor the vital signs of human beings in healthcare applications. In this paper, packet size optimization for BSNs has been analyzed to improve the efficiency of energy consumption. Existing studies on packet size optimization in wireless sensor networks cannot be applied to BSNs because the different operational characteristics of nodes and the channel effects of in‐body and on‐body propagation cannot be captured. In this paper, automatic repeat request (ARQ), forward error correction (FEC) block codes, and FEC convolutional codes have been analyzed regarding their energy efficiency. The hop‐length extension technique has been applied to improve this metric with FEC block codes. The theoretical analysis and the numerical evaluations reveal that exploiting FEC schemes improves the energy efficiency, increases the optimal payload packet size, and extends the hop length for all scenarios for in‐body and on‐body propagation. 相似文献
13.
A mobile ad hoc network (MANET) is a self‐organized and adaptive wireless network formed by dynamically gathering mobile nodes. Since the topology of the network is constantly changing, the issue of routing packets and energy conservation become challenging tasks. In this paper, we propose a cross‐layer design that jointly considers routing and topology control taking mobility and interference into account for MANETs. We called the proposed protocol as Mobility‐aware Routing and Interference‐aware Topology control (MRIT) protocol. The main objective of the proposed protocol is to increase the network lifetime, reduce energy consumption, and find stable end‐to‐end routes for MANETs. We evaluate the performance of the proposed protocol by comprehensively simulating a set of random MANET environments. The results show that the proposed protocol reduces energy consumption rate, end‐to‐end delay, interference while preserving throughput and network connectivity. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
14.
Laetitia Falconetti Reem Karaki Steven Corroy 《Wireless Communications and Mobile Computing》2016,16(16):2436-2448
In this work, we consider a heterogeneous network consisting of macro and pico base stations. Our goal is to associate users to one of the base stations,while minimizing the energy consumption of the network. Moreover, the algorithm should consider constraints of a real system and thus, only include the necessary complexity that helps reducing the energy consumption. Therefore, we first formulate the energy minimization problem in three different manners, each one including a different level of modeling details. The solution of each problem is analyzed to identify the important factors to consider when designing an energy‐optimized cell association algorithm. Based on this analysis, we then develop a practical energy‐aware cell association heuristic. Finally, the developed algorithm is evaluated using complex system simulations. Results show that significant energy savings are achievable by the developed algorithm compared with the conventional cell association in cellular networks. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
15.
刘祥威;郑奎松;李建周;苏倩;张世田 《电波科学学报》2025,40(3):518-525
为了解决在约束性条件下目标外形隐身设计问题,提出了一种基于网格化建模的目标外形优化方案。通过将目标表面离散为精细的网格,针对约束性条件求解出各个网格节点优化范围,并利用矩量法和遗传算法进行散射场计算和优化,通过算法迭代后可以得到优化后的模型结构。优化结果表明,本方法在给定的约束上下界内,可使文中两目标雷达散射截面平均减小超过12 dBsm。该方法能更为精细地调整目标结构,在严格的约束性条件下发挥重要作用,为目标隐身外形优化设计提供了一种新的方案。 相似文献
16.
Konstantinos Katsaros Mehrdad Dianati Zhili Sun Rahim Tafazolli 《Wireless Communications and Mobile Computing》2016,16(8):895-911
This paper presents a comprehensive study of the performance of routing protocols in distributed vehicular networks. We propose a novel and efficient routing protocol, namely cross‐layer, weighted, position‐based routing, which considers link quality, mobility and utilisation of nodes in a cross layer manner to make effective position‐based forwarding decisions. An analytic hierarchy process approach is utilised to combine multiple decision criteria into a single weighting function and to perform a comparative evaluation of the effects of aforementioned criteria on forwarding decisions. Comprehensive simulations are performed in realistic representative urban scenarios with synthetic and real traffic. Insights on the effect of different communication and mobility parameters are obtained. The results demonstrate that the proposed protocol outperforms existing routing protocols for vehicular ad hoc networks, including European Telecommunications Standards Institute (ETSI's) proposed greedy routing protocol, greedy traffic aware routing protocol and advanced greedy forwarding in terms of combined packet delivery ratio, end‐to‐end delay and overhead. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
17.
Xiang Yang Weiping Wang Mingming Lu Jianxin Wang Xi Zhang 《Wireless Communications and Mobile Computing》2016,16(14):1922-1942
Because of the broadcast and overhearing capability of wireless networks, network coding can greatly improve throughput in wireless networks. However, our investigation of existing inter‐session network coding protocols found that the short‐term unfairness that existed in 802.11‐based medium access control (MAC) protocols actually decreases the coding opportunity, which in turn compromises the throughput gain of network coding. To alleviate the negative impact of this unfairness, we propose a coding‐aware cross‐layer heuristic approach to optimize the coordination of network coding and MAC layer protocol, named FairCoding, which can significantly increase coding opportunities for inter‐session network coding through a fair short‐term traffic allocation for different coding flows. Experiment evaluation shows that the proposed mechanism can bring more coding opportunities and improve the total throughput of wireless mesh networks by up to 20%, compared with the coding mechanism, without considering the negative impact of the short‐term unfairness. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
18.
Lei You Ping Wu Mei Song Junde Song Yong Zhang 《Transactions on Emerging Telecommunications Technologies》2011,22(6):296-314
In this paper, we consider a cross‐layer design aimed to enhance performance for uplink transmission in an orthogonal frequency division multiple‐access (OFDMA)‐based cellular network with fixed relay stations. Because mobile stations (MSs) spend most of the power on the uplink transmission, power efficiency resource allocation becomes very important to MSs. We develop a cross‐layer optimisation framework for two types of uplink flows (inelastic and elastic flows) that have different quality‐of‐service requirements. For inelastic flows with fixed‐rate requirement, we formulate the cross‐layer optimisation problem as the minimisation of the sum transmission power of MSs under the constraints of flow conservation law, subcarrier assignment, relaying path selection and power allocation. For elastic flows with flexible‐service‐rate requirement, we consider the cross‐layer trade‐off between uplink service rate and power consumption of MSs and pose the optimisation problem as the maximisation of a linear combination of utility (of service rates) and power consumption (of MSs). Different trade‐offs can be achieved by varying the weighting parameters. Dual decomposition and subgradient methods are used to solve the problems optimally with reduced computational complexity. The simulation results show that, through the proposed cross‐layer resource optimisation framework and algorithms, significant benefits of deployment of multiple fixed relays in an OFDMA cellular network can be fully obtained such as reduction in power consumption, increase in service rate and energy savings in the uplink transmission of MSs. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
19.
Chen Chen Lin Bai Kai Cai Jianhua He Haige Xiang 《Wireless Communications and Mobile Computing》2010,10(8):1017-1032
The performance of wireless networks is limited by multiple access interference (MAI) in the traditional communication approach where the interfered signals of the concurrent transmissions are treated as noise. In this paper, we treat the interfered signals from a new perspective on the basis of additive electromagnetic (EM) waves and propose a network coding based interference cancelation (NCIC) scheme. In the proposed scheme, adjacent nodes can transmit simultaneously with careful scheduling; therefore, network performance will not be limited by the MAI. Additionally we design a space segmentation method for general wireless ad hoc networks, which organizes network into clusters with regular shapes (e.g., square and hexagon) to reduce the number of relay nodes. The segmentation method works with the scheduling scheme and can help achieve better scalability and reduced complexity. We derive accurate analytic models for the probability of connectivity between two adjacent cluster heads which is important for successful information relay. We proved that with the proposed NCIC scheme, the transmission efficiency can be improved by at least 50% for general wireless networks as compared to the traditional interference avoidance schemes. Numeric results also show the space segmentation is feasible and effective. Finally we propose and discuss a method to implement the NCIC scheme in a practical orthogonal frequency division multiplexing (OFDM) communications networks. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
20.
Lin Li Yanheng Liu Jian Wang Tao Wu Peng Zhou 《International Journal of Communication Systems》2018,31(1)
Vehicular Ad‐hoc Networks (VANETs) that are characterized by frequently changed topology, worse signal noise ratio, and non‐negligible Doppler effect introduce new non‐trivial challenges to Quality‐of‐Service (QoS) provisioning. The methodology of cross‐layer optimization aims to jointly optimize the working behaviors over different layers to achieve a better network performance, eg, throughput and transmission latency. This paper presents a novel cross‐layer optimization method based on Partially Observed Markov Games (POMG) to improve optimization decision against the inaccurate observed context caused by high‐speed movement, sensor errors, and other unavoidable reasons. POMG extends Markov Decision Process (MDP) and Partially Observed Markov Decision Process (POMDP) to dynamically adjust the concerned actions (eg, transmission range, contention window, and bit rate) according to the observed traffic density and thus can improve optimization performance at several aspects, eg,, throughput, channel utilization, delay, and total number of neighbor nodes. The extensive simulations show that POMG could harvest a high entire gain compared with the traditional fixed policy and the other cross‐layer optimization schemes. 相似文献