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Impact of spacing and gain imbalance between two dipoles on HSPA throughput performance

ELECTRONICS LETTERS 2009年第21期45卷 1063-1064页

作者： Plicanic, V. Lau, B. K. Sony Ericsson Mobile Commun AB SE-22180 Lund Sweden Lund Univ Elect & Informat Technol Dept SE-22100 Lund Sweden

The throughput performance of two parallel half-wavelength dipoles with different antenna spacings and antenna gain imbalances for two frequency bands in a live High-Speed Packet Access (HSPA) network is reported. It was found that an antenna spacing of 0.25 wavelengths and gain imbalances of up to 6 dB are sufficient to provide significant throughput gain for the same transmit power, or equivalently, an increase in network coverage for a given throughput, as compared to a single dipole.

关键词： diversity reception network coverage WCDMA high-speed packet access network code division multiple access parallel half-wavelength dipoles antenna spacing antenna gain two-frequency band antenna broadband networks dipole antennas multifrequency antennas antenna diversity live HSPA network

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coverage Maximization for Air-and-Ground Cooperative networks

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IEEE WIRELESS COMMUNICATIONS LETTERS 2023年第12期12卷 2113-2117页

作者： Jiang, Ye Zhou, Zihan Zhou, Jiajia Qin, Caina Tang, Wenxin Cai, Zhangjie Zhai, Daosen Zhang, Ruonan Northwestern Polytech Univ Sch Elect & Informat Xian 710072 Shaanxi Peoples R China Southeast Univ Natl Mobile Commun Res Lab Nanjing Jiangsu Peoples R China

How to extend the coverage area is vital for the six-generation mobile communication system (6G). In this letter, we consider a three-tier air-and-ground cooperative network, where some low-altitude relays (LRLs) are deployed to enhance the local coverage of the terrestrial base stations (TBSs) and some high-altitude base stations (HBSs) hover over the region to make up for the wide area coverage hole. To maximize the effective coverage user number, we formulate a joint LRL-position and HBS-trajectory optimization problem by considering the backhaul constraint of the LRLs and the dynamic feature of the HBSs. For the LRL-position optimization, we first remodel it as a maximum weighted independent set problem and then propose a graph-based algorithm to solve it. Furthermore, we combine the bionic algorithms with the deep neural network to devise an effective bionic-learning algorithm, which can quickly solve the complex HBS-trajectory optimization problem. Finally, simulation results demonstrate that our proposed algorithms can significantly improve the network coverage performance and reduce the computational complexity compared with the traditional optimization algorithms.

关键词： network coverage graph theory bionic algorithms deep neural network

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Energy-Efficient Deployment of Water Quality Sensor networks

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Computers, Materials & Continua 2021年第9期68卷 3967-3977页

作者： Qian Sun Zhiping Shen Jinglin Liang Xiaoyi Wang Jiping Xu Li Wang Huiyan Zhang Jiabin Yu Ning Cao Ruichao Wang School of Artificial Intelligence Beijing Technology and Business UniversityBeijing100048China Beijing Laboratory for Intelligent Environmental Protection Beijing100048China Shandong Chengxiang Information Technology Co.Ltd. Dezhou253000China University College Dublin Dublin4Ireland

Water quality sensor networks are promising tools for the exploration of *** key areas need to be monitored *** quality sensors are deployed randomly or uniformly,however,and understanding how to deploy sensor nodes reasonably and realize effective monitoring of key areas on the basis of monitoring the whole area is an urgent problem to be ***,energy is limited in water quality sensor *** moving sensor nodes,we should extend the life cycle of the sensor networks as much as *** this study,sensor nodes in non-key monitored areas are moved to key ***,we used the concentric circle method to determine the mobile sensor nodes and the target ***,we determined the relationship between the mobile sensor nodes and the target locations according to the energy ***,we calculated the shortest moving path according to the Floyd algorithm,which realizes the redeployment of the key monitored *** simulation results showed that,compared with the method of direct movement,the proposed method can effectively reduce the energy consumption and save the network adjustment time based on the effective coverage of key areas.

关键词： Concentric circle method cascaded movement Floyd algorithm network coverage energy

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A Robust coverage Scheme for UWSNs Using the Spline Function

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IEEE SENSORS JOURNAL 2016年第11期16卷 3995-4002页

作者： Cho, Hsin-Hung Shih, Timothy K. Chao, Han-Chieh Natl Cent Univ Dept Comp Sci & Informat Engn Taoyuan 32001 Taiwan Natl Ilan Univ Dept Comp Sci & Informat Engn Yilan 20647 Taiwan Natl Ilan Univ Dept Elect Engn Yilan 20647 Taiwan Natl Dong Hwa Univ Dept Elect Engn Hualien 97401 Taiwan Yangzhou Univ Informat Engn Coll Yangzhou 225009 Jiangsu Peoples R China Fujian Univ Technol Sch Informat Sci & Engn Fuzhou 350108 Peoples R China

Wireless sensor technologies have been in development for a long time. Many wireless sensor technology studies have been conducted on improving device performance. Huge technology resources were recently found under the ocean. Previous research methods cannot mapping the underwater environment directly. Underwater wireless sensor networks are being developed for ocean resources deep water exploration. However, little agreement has been reached on an appropriate underwater dedicated distribution model. We focus on accurately depicting 3-D underwater sensor placement based on the coverage issue. Therefore, we design a novel distribution model using the spline function for more accurate underwater wireless sensor placement.

关键词： Underwater wireless sensor networks network coverage spline function

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On the use of limited autonomous mobility for dynamic coverage maintenance in sensor networks

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COMPUTER networkS 2007年第8期51卷 2126-2143页

作者： Manoj, B. S. Sekhar, Archana Murthy, C. Siva Ram Indian Inst Technol Dept Comp Sci & Engn Madras 600036 Tamil Nadu India McKinsey & Co Inc Bombay 400021 Maharashtra India Univ Calif San Diego Dept Elect & Comp Eng La Jolla CA 92093 USA

Sensor networks consist of small wireless sensor nodes deployed randomly over an area to monitor the environment or detect intrusion. The coverage provided by sensor networks is very crucial to their effectiveness. Many of the important applications of sensor networks demand autonomous mobility for the sensor nodes. Early failure of sensor nodes can lead to coverage loss that requires coverage maintenance schemes. In this paper, we propose Dynamic coverage Maintenance (DCM) schemes that exploit the limited mobility of the sensor nodes. The main objective of coverage maintenance is to compensate the loss of coverage with minimum expenditure of energy. Existing autonomous sensor deployment schemes such as the "potential field approach" are not useful for DCM because the nodes initially distribute themselves such that there is no redundancy in coverage. We propose a set of DCM schemes which can be executed on individual sensor nodes having a knowledge of only their local neighborhood topology. The process of moving a node to a new location for maintenance of coverage is termed "migration". We propose four algorithms to decide which neighbors to migrate, and to what distance, such that the energy expended is minimized and the coverage obtained for a given number of live nodes is maximized. The decision and movement are completely autonomous in the network, and involves movement of one-hop neighbors of a dead sensor node. We also propose an extension to these algorithms, called Cascaded DCM, which extends the migrations to multiple hops. We have developed a graphical simulator Java Sensor Simulator (JSS) to visually inspect the working of the algorithms. We have also compared the performance of the different algorithms in terms of the improvement in coverage, average migration distance of the nodes, and the lifetime of the network. Cascaded DCM was seen to offer the maximum network lifetime and coverage. (c) 2006 Elsevier B.V. All rights reserved.

关键词： limited autonomous mobility sensor networks network coverage migration

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A Survey on coverage Enhancement in Cellular networks: Challenges and Solutions for Future Deployments

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IEEE COMMUNICATIONS SURVEYS AND TUTORIALS 2021年第2期23卷 1302-1341页

作者： Borralho, Ruben Mohamed, Abdelrahim Quddus, Atta Ul Vieira, Pedro Tafazolli, Rahim Univ Surrey Home 5GIC Inst Commun Syst ICS Guildford GU2 7XH Surrey England Celfinet Outstanding Networks Res Dept P-1495764 Lisbon Portugal Telecommun Inst Lisbon Portugal Inst Super Engn Lisboa ISEL Area Dept Engn Elect & Telecomunicacoes & Comp AD P-959007 Lisbon Portugal

Seamless and ubiquitous coverage are key factors for future cellular networks. Despite capacity and data rates being the main topics under discussion when envisioning the Fifth Generation (5G) and beyond of mobile communications, network coverage remains one of the major issues since coverage quality highly impacts the system performance and end-user experience. The increasing number of base stations and user terminals is anticipated to negatively impact the network coverage due to increasing interference. Furthermore, the "ubiquitous coverage" use cases, including rural and isolated areas, present a significant challenge for mobile communication technologies. This survey presents an overview of the concept of coverage, highlighting the ways it is studied, measured, and how it impacts the network performance. Additionally, an overlook of the most important key performance indicators influenced by coverage, which may affect the envisioned use cases with respect to throughput, latency, and massive connectivity, are discussed. Moreover, the main existing developments and deployments which are expected to augment the network coverage, in order to meet the requirements of the emerging systems, are presented as well as implementation challenges.

关键词： Interference Cellular networks Throughput Planning 5G mobile communication Telecommunications Signal to noise ratio Cellular networks frequency bands interference management network coverage network deployments spectrum management

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An efficient trajectory design for mobile sink in a wireless sensor network

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COMPUTERS & ELECTRICAL ENGINEERING 2014年第7期40卷 2089-2100页

作者： Ghafoor, Saim Rehmani, Mubashir Husain Cho, Sunghyun Park, Sung-Han Hanyang Univ Dept Comp Sci & Engn Ansan South Korea Natl Univ Ireland Univ Coll Cork Dept Comp Sci Cork Ireland COMSATS Inst Informat Technol Dept Elect Engn Wah Cantt Pakistan

Mobile sink trajectory plays a pivotal role for network coverage, data collection and data dissemination in wireless sensor networks. Considering this, we propose a novel approach for mobile sink trajectory in wireless sensor networks. Our proposed approach is based on Hilbert Space Filling Curve, however, the proposed approach is different from the previous work in a sense that the curve order changes according to node density. In this paper, we investigate the mobile sink trajectory based on Hilbert Curve Order which depends upon the size of the network. Second, we calculate the Hilbert Curve Order based on node density to redimension the mobile sink trajectory. Finally, we perform extensive simulations to evaluate the effectiveness of proposed approach in terms of network coverage and scalability. Simulation results confirm that our proposed approach outperforms with size based Hilbert Curve in terms of network coverage, packet delivery ratio and average energy consumption. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Data dissemination Hilbert Space Filling Curve Mobile sink trajectory network coverage Node density Wireless sensor network

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A Sleep Scheduling Target Tracking Research for Sensor networks

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WIRELESS PERSONAL COMMUNICATIONS 2020年第3期111卷 1723-1740页

作者： Qiong, Peng Wang, Jingfang Hunan Int Econ Univ Sch Informat & Electromech Engn Changsha 410205 Hunan Peoples R China

Moving target tracking of sensor networks is an important application. The sensor nodes cooperate in the networks to discover the target, and the target's perceptual information is feeded back to the user. In order to effectively reduce the network energy consumption and improve the tracking quality, a target tracking protocol is proposed based on two-stage sleep scheduling. The whole tracking process is divided into two stages in the protocol. According to the different requirements of node density, the different sleep scheduling mechanism is adopted. In this paper, the proposed protocol is further optimized to ensure the tracking quality while minimizing system energy consumption. Finally, the validity of the proposed protocol was verified with 36 sensor nodes.

关键词： Target tracking Wireless sensor networks (WSN) Sleep scheduling network coverage network partitioning

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A Distributed Topological Camera network Representation for Tracking Applications

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2010年第10期19卷 2516-2529页

作者： Lobaton, Edgar Vasudevan, Ramanarayan Bajcsy, Ruzena Sastry, Shankar Univ N Carolina Dept Comp Sci Chapel Hill NC 27599 USA Univ Calif Berkeley Dept Elect Engn & Comp Sci Berkeley CA 94720 USA

Sensor networks have been widely used for surveillance, monitoring, and tracking. Camera networks, in particular, provide a large amount of information that has traditionally been processed in a centralized manner employing a priori knowledge of camera location and of the physical layout of the environment. Unfortunately, these conventional requirements are far too demanding for ad-hoc distributed networks. In this article, we present a simplicial representation of a camera network called the camera network complex (CN-complex), that accurately captures topological information about the visual coverage of the network. This representation provides a coordinate-free calibration of the sensor network and demands no localization of the cameras or objects in the environment. A distributed, robust algorithm, validated via two experimental setups, is presented for the construction of the representation using only binary detection information. We demonstrate the utility of this representation in capturing holes in the coverage, performing tracking of agents, and identifying homotopic paths.

关键词： Multitarget tracking network coverage sensor networks simplicial homology smart camera networks

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Multi-Objective MDP-Based Routing in UAV networks for Search-Based Operations

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2024年第9期73卷 13777-13789页

作者： Mahajan, Prateek Palanisamy, Balamurugan Kumar, Anusha Chalapathi, G. S. S. Chamola, Vinay Khabbaz, Maurice Birla Inst Technol & Sci BITS Pilani Dept Elect & Elect Engn EEE Pilani 333031 India Amer Univ Beirut Comp Sci Dept 11-0236-CMPS Beirut Lebanon

Unmanned aerial vehicle (UAV) systems have gained widespread recognition due to their versatility and autonomy. Their deployment for disaster mitigation and management operations is seen as one of their most important applications over the past decade. In such UAV networks, routing plays a crucial role in determining network performance parameters such as network lifetime, data transmission latency, and packet delivery ratio. This paper presents a novel routing mechanism - Multi-Objective Markov Decision Based Routing (MOBMDP) for UAV networks carrying out search-based operations. MOBMDP models routing decisions in a Markov Decision Process (MDP) framework and uses Q-learning to take decisions. It compares routing paths using three metrics, viz., Remaining Energy of the Minimum Energy Node (REMEN), Power Distance ratio (PD), and Expected Delay (ED). Amongst these metrics, PD is a novel metric proposed by this work. PD simultaneously optimizes the energy efficiency and energy distribution in the network. Further, MOBMDP uses a novel reinforcement learning inspired method to estimate transmission delay in a given path. Intensive simulation studies compare MOBMDP to four state-of-the-art routing protocols. Results show a significant improvement in network lifetime, packet delivery ratio, energy efficiency, average data transmission delay, and error in delay estimation.

关键词： Routing Delays Autonomous aerial vehicles Prediction algorithms Q-learning Routing protocols Measurement UAV search and rescue placement algorithm routing protocol network lifetime network coverage transmission delay estimation energy efficiency

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