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COMPUTER SCIENCE (1157 journals)                  1 2 3 4 5 6 | Last

Showing 1 - 200 of 872 Journals sorted alphabetically
3D Printing and Additive Manufacturing     Full-text available via subscription   (Followers: 13)
Abakós     Open Access   (Followers: 3)
Academy of Information and Management Sciences Journal     Full-text available via subscription   (Followers: 69)
ACM Computing Surveys     Hybrid Journal   (Followers: 22)
ACM Journal on Computing and Cultural Heritage     Hybrid Journal   (Followers: 9)
ACM Journal on Emerging Technologies in Computing Systems     Hybrid Journal   (Followers: 13)
ACM Transactions on Accessible Computing (TACCESS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 16)
ACM Transactions on Applied Perception (TAP)     Hybrid Journal   (Followers: 6)
ACM Transactions on Architecture and Code Optimization (TACO)     Hybrid Journal   (Followers: 9)
ACM Transactions on Autonomous and Adaptive Systems (TAAS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Computation Theory (TOCT)     Hybrid Journal   (Followers: 11)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 4)
ACM Transactions on Computer Systems (TOCS)     Hybrid Journal   (Followers: 18)
ACM Transactions on Computer-Human Interaction     Hybrid Journal   (Followers: 13)
ACM Transactions on Computing Education (TOCE)     Hybrid Journal   (Followers: 3)
ACM Transactions on Design Automation of Electronic Systems (TODAES)     Hybrid Journal   (Followers: 1)
ACM Transactions on Economics and Computation     Hybrid Journal  
ACM Transactions on Embedded Computing Systems (TECS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Information Systems (TOIS)     Hybrid Journal   (Followers: 20)
ACM Transactions on Intelligent Systems and Technology (TIST)     Hybrid Journal   (Followers: 8)
ACM Transactions on Interactive Intelligent Systems (TiiS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMCCAP)     Hybrid Journal   (Followers: 10)
ACM Transactions on Reconfigurable Technology and Systems (TRETS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Sensor Networks (TOSN)     Hybrid Journal   (Followers: 8)
ACM Transactions on Speech and Language Processing (TSLP)     Hybrid Journal   (Followers: 11)
ACM Transactions on Storage     Hybrid Journal  
ACS Applied Materials & Interfaces     Full-text available via subscription   (Followers: 21)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Ad Hoc Networks     Hybrid Journal   (Followers: 11)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Advanced Engineering Materials     Hybrid Journal   (Followers: 26)
Advanced Science Letters     Full-text available via subscription   (Followers: 7)
Advances in Adaptive Data Analysis     Hybrid Journal   (Followers: 8)
Advances in Artificial Intelligence     Open Access   (Followers: 16)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 15)
Advances in Computer Science : an International Journal     Open Access   (Followers: 13)
Advances in Computing     Open Access   (Followers: 2)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 53)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 10)
Advances in Human-Computer Interaction     Open Access   (Followers: 20)
Advances in Materials Sciences     Open Access   (Followers: 16)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 37)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Advances in Technology Innovation     Open Access   (Followers: 1)
AEU - International Journal of Electronics and Communications     Hybrid Journal   (Followers: 8)
African Journal of Information and Communication     Open Access   (Followers: 6)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 4)
Air, Soil & Water Research     Open Access   (Followers: 7)
AIS Transactions on Human-Computer Interaction     Open Access   (Followers: 6)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1)
Algorithms     Open Access   (Followers: 11)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 4)
American Journal of Computational Mathematics     Open Access   (Followers: 4)
American Journal of Information Systems     Open Access   (Followers: 7)
American Journal of Sensor Technology     Open Access   (Followers: 4)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2)
Analog Integrated Circuits and Signal Processing     Hybrid Journal   (Followers: 7)
Analysis in Theory and Applications     Hybrid Journal   (Followers: 1)
Animation Practice, Process & Production     Hybrid Journal   (Followers: 5)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Data Science     Hybrid Journal   (Followers: 9)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 6)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Software Engineering     Hybrid Journal   (Followers: 12)
Annual Reviews in Control     Hybrid Journal   (Followers: 6)
Anuario Americanista Europeo     Open Access  
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applied and Computational Harmonic Analysis     Full-text available via subscription   (Followers: 2)
Applied Artificial Intelligence: An International Journal     Hybrid Journal   (Followers: 14)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Clinical Informatics     Hybrid Journal   (Followers: 2)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Computer Systems     Open Access   (Followers: 1)
Applied Informatics     Open Access  
Applied Mathematics and Computation     Hybrid Journal   (Followers: 32)
Applied Medical Informatics     Open Access   (Followers: 10)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Soft Computing     Hybrid Journal   (Followers: 16)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Architectural Theory Review     Hybrid Journal   (Followers: 3)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 5)
Archive of Numerical Software     Open Access  
Archives and Museum Informatics     Hybrid Journal   (Followers: 125)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Artifact     Hybrid Journal   (Followers: 2)
Artificial Life     Hybrid Journal   (Followers: 6)
Asia Pacific Journal on Computational Engineering     Open Access  
Asia-Pacific Journal of Information Technology and Multimedia     Open Access   (Followers: 1)
Asian Journal of Computer Science and Information Technology     Open Access  
Asian Journal of Control     Hybrid Journal  
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
Australian Educational Computing     Open Access  
Automatic Control and Computer Sciences     Hybrid Journal   (Followers: 3)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Automatica     Hybrid Journal   (Followers: 9)
Automation in Construction     Hybrid Journal   (Followers: 6)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Basin Research     Hybrid Journal   (Followers: 5)
Behaviour & Information Technology     Hybrid Journal   (Followers: 52)
Bioinformatics     Hybrid Journal   (Followers: 308)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 31)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 46)
British Journal of Educational Technology     Hybrid Journal   (Followers: 123)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
c't Magazin fuer Computertechnik     Full-text available via subscription   (Followers: 2)
CALCOLO     Hybrid Journal  
Calphad     Hybrid Journal  
Canadian Journal of Electrical and Computer Engineering     Full-text available via subscription   (Followers: 14)
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal  
Cell Communication and Signaling     Open Access   (Followers: 1)
Central European Journal of Computer Science     Hybrid Journal   (Followers: 5)
CERN IdeaSquare Journal of Experimental Innovation     Open Access  
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
ChemSusChem     Hybrid Journal   (Followers: 7)
China Communications     Full-text available via subscription   (Followers: 7)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
CIN Computers Informatics Nursing     Full-text available via subscription   (Followers: 12)
Circuits and Systems     Open Access   (Followers: 16)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
CLEI Electronic Journal     Open Access  
Clin-Alert     Hybrid Journal   (Followers: 1)
Cluster Computing     Hybrid Journal   (Followers: 1)
Cognitive Computation     Hybrid Journal   (Followers: 4)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Communication Methods and Measures     Hybrid Journal   (Followers: 11)
Communication Theory     Hybrid Journal   (Followers: 20)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Algebra     Hybrid Journal   (Followers: 3)
Communications in Partial Differential Equations     Hybrid Journal   (Followers: 3)
Communications of the ACM     Full-text available via subscription   (Followers: 53)
Communications of the Association for Information Systems     Open Access   (Followers: 18)
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering     Hybrid Journal   (Followers: 3)
Complex & Intelligent Systems     Open Access  
Complex Adaptive Systems Modeling     Open Access  
Complex Analysis and Operator Theory     Hybrid Journal   (Followers: 2)
Complexity     Hybrid Journal   (Followers: 6)
Complexus     Full-text available via subscription  
Composite Materials Series     Full-text available via subscription   (Followers: 9)
Computación y Sistemas     Open Access  
Computation     Open Access  
Computational and Applied Mathematics     Hybrid Journal   (Followers: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 2)
Computational and Structural Biotechnology Journal     Open Access   (Followers: 2)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Astrophysics and Cosmology     Open Access   (Followers: 1)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computational Cognitive Science     Open Access   (Followers: 2)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Condensed Matter     Open Access  
Computational Ecology and Software     Open Access   (Followers: 9)
Computational Economics     Hybrid Journal   (Followers: 9)
Computational Geosciences     Hybrid Journal   (Followers: 14)
Computational Linguistics     Open Access   (Followers: 23)
Computational Management Science     Hybrid Journal  
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 4)
Computational Methods and Function Theory     Hybrid Journal  
Computational Molecular Bioscience     Open Access   (Followers: 2)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Particle Mechanics     Hybrid Journal   (Followers: 1)
Computational Research     Open Access   (Followers: 1)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computational Science and Techniques     Open Access  
Computational Statistics     Hybrid Journal   (Followers: 13)
Computational Statistics & Data Analysis     Hybrid Journal   (Followers: 31)
Computer     Full-text available via subscription   (Followers: 84)
Computer Aided Surgery     Hybrid Journal   (Followers: 3)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Communications     Hybrid Journal   (Followers: 10)
Computer Engineering and Applications Journal     Open Access   (Followers: 5)
Computer Journal     Hybrid Journal   (Followers: 7)
Computer Methods in Applied Mechanics and Engineering     Hybrid Journal   (Followers: 22)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 10)
Computer Methods in the Geosciences     Full-text available via subscription   (Followers: 1)
Computer Music Journal     Hybrid Journal   (Followers: 16)
Computer Physics Communications     Hybrid Journal   (Followers: 6)
Computer Science - Research and Development     Hybrid Journal   (Followers: 7)
Computer Science and Engineering     Open Access   (Followers: 17)
Computer Science and Information Technology     Open Access   (Followers: 11)
Computer Science Education     Hybrid Journal   (Followers: 12)
Computer Science Journal     Open Access   (Followers: 20)
Computer Science Master Research     Open Access   (Followers: 10)
Computer Science Review     Hybrid Journal   (Followers: 10)

        1 2 3 4 5 6 | Last

Journal Cover Ad Hoc Networks
  [SJR: 0.967]   [H-I: 57]   [11 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1570-8705
   Published by Elsevier Homepage  [3044 journals]
  • Interference aware bandwidth estimation for load balancing in EMHR-energy
           based with mobility concerns hybrid routing protocol for VANET-WSN
    • Authors: Linda F. Mohaisen; Laurie L. Joiner
      Pages: 1 - 15
      Abstract: Publication date: November 2017
      Source:Ad Hoc Networks, Volume 66
      Author(s): Linda F. Mohaisen, Laurie L. Joiner
      The main goal of Vehicular Ad Hoc Networks (VANETs) is to improve driving safety. However, VANETs may not guarantee timely detection of dangerous road conditions or maintain communication connectivity when the network density is low, which may pose a risk to driving safety. Towards addressing this problem, the VANET is integrated with the inexpensive Wireless Sensor Network (WSN). Sensor nodes are deployed along the roadside to sense road conditions, and to buffer and deliver information about dangerous conditions to vehicles regardless of the density or connectivity of the VANET. The most challenging features in VANETs are their dynamic topology and mobility, where vehicles are moving at variable and high speeds and in different trajectories. In contrast, the challenge in the WSN is in managing the limited energy resources of the nodes, since the performance of WSNs strongly depends on their lifetime. Thus, the fundamental design challenge in designing routing protocols for a hybrid network of VANET-WSN is to maximize network lifetime and connectivity, and to minimize delay and energy consumption. To overcome these challenges, this research investigates the effects of different Quality of Service (QoS) parameters on forwarding decisions in an efficient distributed position based routing protocol, and focuses on bandwidth estimation. Bandwidth estimation is of great importance to network Quality of Service assurance, network load balancing, and routing. In this research, a bandwidth estimation strategy based on normalized throughput of a link, taking into account the interference and packet loss ratio in discrete time for every successfully delivered packet is proposed for a hybrid network of VANET-WSN. The simulation results show that the strategy is effective, and can accurately estimate the bandwidth of VANET-WSN. A comprehensive performance analysis in representative urban scenarios is performed that takes into account realistic propagation models and real city scenario traffic.

      PubDate: 2017-08-27T15:13:13Z
      DOI: 10.1016/j.adhoc.2017.08.004
      Issue No: Vol. 66 (2017)
  • A location aided controlled spraying routing algorithm for Delay Tolerant
    • Authors: Hang Guo; Xingwei Wang; Hui Cheng; Min Huang
      Pages: 16 - 25
      Abstract: Publication date: November 2017
      Source:Ad Hoc Networks, Volume 66
      Author(s): Hang Guo, Xingwei Wang, Hui Cheng, Min Huang
      Delay Tolerant Networks (DTNs) often suffer from intermittent disruption and variable long delay due to factors such as mobility and energy. In this paper, a Location Aided Controlled Spraying (LACS) routing algorithm is proposed to deal with the challenging issues in DTN routing. Only the routing information carried by the contacted nodes is needed in this algorithm, and there is no need for global networks knowledge and hardware support. The routing process is divided into two stages, i.e., controlled spraying routing stage and single-copy routing stage. The maximum transfer throughput of the contact is checked before each message is forwarded. During the controlled spraying stage, the current node adjusts spraying strategy according to the encounter angle of the contact nodes. During the single-copy stage, a location prediction model based on the semi-Markov process (SMP) is introduced, and the node's behaviors can be captured both in the temporal and spatial domains with this model. The current node predicts the destination node's location, and then decides whether to forward the message to target node based on the time used for meeting the destination node. Simulation results show that the proposed algorithm can achieve better performance than the traditional routing schemes of DTNs in terms of delivery ratio, network overhead and transmission delay under both random node movement model and realistic trace scenario.

      PubDate: 2017-08-27T15:13:13Z
      DOI: 10.1016/j.adhoc.2017.08.005
      Issue No: Vol. 66 (2017)
  • IoT_ProSe: Exploiting 3GPP services for task allocation in the Internet of
    • Authors: Virginia Pilloni; Emad Abd-Elrahman; Makhlouf Hadji; Luigi Atzori; Hossam Afifi
      Pages: 26 - 39
      Abstract: Publication date: November 2017
      Source:Ad Hoc Networks, Volume 66
      Author(s): Virginia Pilloni, Emad Abd-Elrahman, Makhlouf Hadji, Luigi Atzori, Hossam Afifi
      This work focuses on the problem of task allocation among mobile objects that aim to collaborate in the execution of IoT (Internet of Things) applications. We consider 3GPP Proximity Services (ProSe) that enable Device to Device (D2D) communications for direct interaction among IoT objects. We first define the framework where devices willing to cooperate: (i) discover and join a cluster of objects to take part to the IoT_ProSe service; (ii) compete with the other objects in the cluster when a request for a service is sent to the cluster from the IoT application server. We then focus on two important problems. The first problem is the decision about which node should win the competition, for which we propose a game-theory based approach to find a solution maximizing objects’ utility functions. The second problem is the computation of the optimal size of devices’ clusters within a cell by maximizing the signal quality across the cell. Experimental results provide insights on the strategy performance. By appropriately setting working parameters, it is possible to improve system reliability up to 21%, and system lifetime up to 68%.

      PubDate: 2017-08-27T15:13:13Z
      DOI: 10.1016/j.adhoc.2017.08.006
      Issue No: Vol. 66 (2017)
  • Flexible resource allocation adaptive to communication strategy selection
           for cellular clients using Stackelberg game
    • Authors: Jinsong Gui; Yijia Lu; Xiaoheng Deng; Anfeng Liu
      Pages: 64 - 84
      Abstract: Publication date: November 2017
      Source:Ad Hoc Networks, Volume 66
      Author(s): Jinsong Gui, Yijia Lu, Xiaoheng Deng, Anfeng Liu
      In cooperative communication Networks (or cooperative cognitive radio networks), a source node usually recruits non-altruistic relays to execute cooperative communication with a target node, through compensating these potential relays with a fraction of its licensed frequency band. When a source node is far apart from a target node, it is difficult to achieve the desired transmission performance by cooperative communication. In this paper, a source node's communication strategy can dynamically be adjusted with help of a base station according to variation of wireless communication environments. Also, an appropriate relaying path can be constructed to replace a long-distance wireless link without demand of channel state information. Furthermore, following the proposed Stackelberg game-theoretic method based on three-party-cooperation, a base station can determine the preliminary division of a source node's licensed frequency band and the initial power allocation for all the relays in the same relaying path, while the source node and the related relays can dynamically adjust them respectively during data transmission according to information feedback.

      PubDate: 2017-09-11T12:49:24Z
      DOI: 10.1016/j.adhoc.2017.08.003
      Issue No: Vol. 66 (2017)
  • An adaptive stabilizing imposter detection scheme for distributed mobile
           wireless sensor networks
    • Authors: Ebrahim A. Alrashed; Mehmet H. Karaata; Ali Hamdan; Badour Albahar
      Pages: 1 - 12
      Abstract: Publication date: October 2017
      Source:Ad Hoc Networks, Volume 65
      Author(s): Ebrahim A. Alrashed, Mehmet H. Karaata, Ali Hamdan, Badour Albahar
      Mobile wireless sensor networks (MWSNs) are wireless networks of small sensors moving around a certain coverage area relaying information among themselves and conveying their readings and data to base stations. Imposters are malicious nodes actively engaging other legitimate nodes in the network to read or inject wrong data. MWSN are susceptible to imposter attack and therefore, the protection of MWSN from imposter nodes placed by an adversary to contaminate the sensed data is essential for the reliability of its operation. Imposters detection algorithms need to be distributed in nature and therefore they are susceptible to variety of faults that can perturb the variables for algorithm and cause a major malfunction in the operation of the algorithm and subsequently the entire network if proper recovery mechanisms are not employed. The distributed nature of imposter detection schemes for WSN and the physical environment where the sensors are deployed require some approaches such as stabilization to deal with faults. A stabilizing distributed algorithm can withstand transient faults and start in an arbitrary initial configuration by eventually entering a legitimate system configuration regardless of the current system configuration. We view a fault as a transient fault if it affects the states of the system processes but not their program. In this paper, we propose an imposter detection scheme that can effectively deal with transient faults and arbitrary initialization. In addition, the proposed algorithm effectively adapts to the introduction and the removal of sensor nodes to/from the WSN which makes the proposed algorithm appropriate for practical sensor network applications. Other faults that can occur in the network and in the nodes are beyond the scope of this work.

      PubDate: 2017-07-24T04:41:55Z
      DOI: 10.1016/j.adhoc.2017.07.003
      Issue No: Vol. 65 (2017)
  • A review of broadcasting safety data in V2V: Weaknesses and requirements
    • Authors: Hanaa S. Basheer; Carole Bassil
      Pages: 13 - 25
      Abstract: Publication date: October 2017
      Source:Ad Hoc Networks, Volume 65
      Author(s): Hanaa S. Basheer, Carole Bassil
      One of the main goals in using vehicular ad hoc networks (VANETs) system is to provide the driver of a vehicle with services that helps him/her in avoiding chain accidents and traffic jam. Vehicles can get different services from global servers when connecting to the internet or can cooperate with each other, where each vehicle behaves as a collector for traffic information and a disseminator of necessary data to the neighbouring vehicles during their journey. However, disseminating safety data between connecting vehicles is a challenging task due to the quick change in the wireless network topology, and the broadcast protocol's reliance on many physical parameters (e.g. vehicle's speed, location, roads structures etc.). Thus, getting a reliable VANET system and ensuring the integrity of messages are the main objectives when introducing any dissemination method. This paper reviews several existing VANET safety applications, and revises the disseminating methods for safety messages between vehicles without infrastructure to cover a wide area in a quick reliable way. Wherefore we include relevant works that present different methods to broadcast the warning message between vehicles, particularly when no infrastructure is available. Towards the conclusion, we show a classification tabular for these works, and a comprehensive feedback to reach the optimal perception of the broadcast scheme during safety data dissemination that depends on three objects; the environment, the vehicle as a sender, and the vehicle as a receiver.

      PubDate: 2017-08-03T11:34:09Z
      DOI: 10.1016/j.adhoc.2017.07.004
      Issue No: Vol. 65 (2017)
  • Quantized feedback scheduling for MIMO-OFDM broadcast networks with
           subcarrier clustering
    • Authors: Prabina Pattanayak; Preetam Kumar
      Pages: 26 - 37
      Abstract: Publication date: October 2017
      Source:Ad Hoc Networks, Volume 65
      Author(s): Prabina Pattanayak, Preetam Kumar
      Feedback of user channel quality information (CQI) to base station (BS) is essential for efficient scheduling of multi-user (MU) multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) broadcast networks. This feedback overload increases linearly with the cardinality of users, transmit antennas and subcarriers present in MIMO-OFDM systems. Hence, clustering of adjacent subcarriers has been considered in literature for reduction in feedback load. Here users communicate the CQI of the center subcarrier of the clusters assuming that subcarriers of a cluster experience similar channel conditions. However, this method leads to inefficient resource scheduling for higher cluster sizes as it does not take advantage of CQI of other subcarriers that experience non-uniform channel conditions. This reason motivated us to develop a new limited feedback scheduling scheme where quantization of CQI with multiple bits is implemented along with clustering of adjacent subcarriers. In this scheme, the multi-bit quantized CQI of all the subcarriers of a cluster are examined for the efficient scheduling along with further reduction in the feedback overhead. Moreover, we proposed a less time consuming method to find the optimum quantization thresholds that play significant role in multi-bit quantization process by using genetic algorithm (GA). This GA methodology is computationally more efficient than exhaustive search process.

      PubDate: 2017-08-03T11:34:09Z
      DOI: 10.1016/j.adhoc.2017.07.007
      Issue No: Vol. 65 (2017)
  • Spectrum access in cognitive smart-grid communication system with
           prioritized traffic
    • Authors: Ram Narayan Yadav; Rajiv Misra; Sourabh Bhagat
      Pages: 38 - 54
      Abstract: Publication date: October 2017
      Source:Ad Hoc Networks, Volume 65
      Author(s): Ram Narayan Yadav, Rajiv Misra, Sourabh Bhagat
      Smart grid (SG) comprises heterogeneous characteristics of traffic such as control commands (safety, sensing, smart-meter readings) among power generation, transmission and end users. An effective and reliable two-way communication infrastructure between users and utility providers is important for improving the performance of smart grid. To support such traffic types in the smart grid, we have studied cognitive radio communication infrastructure-based smart grid. In this paper, we proposed a prioritized spectrum access scheme for cognitive smart grid communication systems to address the quality of service (QoS) requirements of heterogeneous traffic. SG traffic is categorized into two priority classes (high and low based on service requirements). We model the proposed spectrum access scheme (by considering the spectrum sensing error) using a multidimensional Markov chain. We have measured the performance based on the blocking probability, the dropping probability, the interference probability and the call completion rate for both the traffic types (high and the low class smart grid traffic). By Considering an environment where the traffic is heavy tailed, we have modeled the arrivals to follow a Pareto distribution, as the Poisson process model may under estimate the traffic especially when traffic is heavy tailed. The results illustrate that the proposed priority based scheme is able to significantly improve the QoS of high-priority traffic. It is also observed that the prioritized system is preferable over the non-prioritized system where all traffic types are treated the same in terms of SG data delivery.

      PubDate: 2017-08-03T11:34:09Z
      DOI: 10.1016/j.adhoc.2017.07.005
      Issue No: Vol. 65 (2017)
  • Performance of RF self-interference cancellation disturbed by fast-moving
           object in full-duplex wireless
    • Authors: Fei Wu; Chuan Huang; Youxi Tang
      Pages: 55 - 64
      Abstract: Publication date: October 2017
      Source:Ad Hoc Networks, Volume 65
      Author(s): Fei Wu, Chuan Huang, Youxi Tang
      In this paper, the performance of radio frequency (RF) self-interference (SI) cancellation in presence of flying/moving object is analyzed to achieve an uninterrupted FD transmission and reception. The SI leaked typically consists of two parts: slow time-varying SI and burst SI part. For simplification, slow time-varying SI part can be effectively suppressed. In addition, burst SI part can be modeled as a single path SI signal. To detect and estimate the burst SI part, superimposing training sequence is introduced in the transmit signals. Correspondingly, one special RF tap is adopted to suppress the burst SI part. Based on this scheme, the expression of instantaneous and average outage probability is derived and this can be solved by numerical method. It is found that the FD outage probability is significantly influenced by the flying/moving object velocity, by Doppler frequency, by the distance between the flying/moving object and the transceiver antenna, and the transmitter signal-to-training ratio.

      PubDate: 2017-08-03T11:34:09Z
      DOI: 10.1016/j.adhoc.2017.07.009
      Issue No: Vol. 65 (2017)
  • Design and analysis of RPL objective functions for multi-gateway ad-hoc
           low-power and lossy networks
    • Authors: Muhammad Omer Farooq; Cormac J. Sreenan; Kenneth N. Brown; Thomas Kunz
      Pages: 78 - 90
      Abstract: Publication date: October 2017
      Source:Ad Hoc Networks, Volume 65
      Author(s): Muhammad Omer Farooq, Cormac J. Sreenan, Kenneth N. Brown, Thomas Kunz
      RPL is a standard routing framework for low-power and lossy networks (LLNs). LLNs usually operate in challenged conditions, therefore RPL can be adapted to satisfy requirements of a particular LLN. RPL facilitates this through objective functions (OFs). An OF is used to discover and maintain data forwarding paths based on the requirements of LLNs. In RPL, different OFs can use different routing metrics in different ways. In this paper, we design different OFs and analyse their impact on RPL performance in multi-gateway ad-hoc LLNs. In conjunction with the shortest hop-count, our designed OFs also use the following tie-breaking metrics: available bandwidth, delay, buffer occupancy, and ETX. Our OFs use the tie-breaking metrics on a greedy or an end-to-end basis. In our experimental analysis, we consider the impact of duty-cycling, number of gateways, and data traffic load on the OFs’ performance. Our results demonstrate that, generally speaking, the performance improves with an increase in the number of gateways. In the absence of duty-cycling, the greedy approach is better compared to the end-to-end approach, and using delay, buffer occupancy, and ETX metrics as the tie-breaking metrics in conjunction with the shortest hop-count metric yield the best performance. In a relatively high data traffic load, all OFs perform similarly. In duty-cycling mode, frequent changes in the parent node incur extra synchronization time between a sender and receiver. OFs that use the tie-breaking metrics on an end-to-end basis do not frequently change parent nodes, hence they demonstrate better performance. Furthermore, in duty-cycling mode, the shortest hop-count metric demonstrates the best performance compared to the other metrics.

      PubDate: 2017-08-27T15:13:13Z
      DOI: 10.1016/j.adhoc.2017.08.002
      Issue No: Vol. 65 (2017)
  • Recent advances in RF-based passive device-free localisation for indoor
    • Authors: Sameera Palipana; Bastien Pietropaoli; Dirk Pesch
      Pages: 80 - 98
      Abstract: Publication date: September 2017
      Source:Ad Hoc Networks, Volume 64
      Author(s): Sameera Palipana, Bastien Pietropaoli, Dirk Pesch
      Radio frequency (RF) based indoor localisation techniques have gained much attention over the past nearly three decades. Such techniques can be classified as active and passive while passive systems can have either device-assisted or device-free characteristics. Device-free localisation can be a prominent research field as it transcends other device-based approaches in certain application scenarios. Accordingly, we have witnessed an influx of IDFL research focusing on multiple disciplines including occupancy, positioning, activity and identity. However, despite the recent emergence of several exciting technologies and corresponding techniques, IDFL faces some important challenges and because of this, we haven’t come across many mainstream commercial products using RF-based IDFL techniques. In this article, we survey the recent progress of IDFL prioritising on indoor positioning. We decompose the localisation dimensions into occupants, space and time, provide a detailed taxonomy and a comprehensive review of these techniques. We divide the state of the art mainly into Wireless Network-based and Radar-based, evaluate the respective technologies and the techniques qualitatively, discuss trends, limitations and also indicate future research directions relevant to this field.

      PubDate: 2017-07-03T01:44:23Z
      DOI: 10.1016/j.adhoc.2017.06.007
      Issue No: Vol. 64 (2017)
  • Estimating the Medium Access Probability in Large Cognitive Radio Networks
    • Authors: Claudina Rattaro; Federico Larroca; Paola Bermolen; Pablo Belzarena
      Pages: 1 - 13
      Abstract: Publication date: Available online 20 May 2017
      Source:Ad Hoc Networks
      Author(s): Claudina Rattaro, Federico Larroca, Paola Bermolen, Pablo Belzarena
      During the last decade we have seen an explosive development of wireless technologies. Consequently the demand for electromagnetic spectrum has been growing dramatically resulting in the spectrum scarcity problem. In spite of this, spectrum utilization measurements have shown that licensed bands are vastly underutilized while unlicensed bands are too crowded. In this context, Cognitive Radio Network emerges as an auspicious paradigm in order to solve those problems. The main question that motivates this work is: what are the possibilities offered by cognitive radio to improve the effectiveness of spectrum utilization? With this in mind, we propose a methodology, based on configuration models for random graphs, to estimate the medium access probability of secondary users. We perform simulations to illustrate the accuracy of our results and we also make a performance comparison between our estimation and one obtained by a stochastic geometry approach.

      PubDate: 2017-05-22T12:52:34Z
      DOI: 10.1016/j.adhoc.2017.05.003
      Issue No: Vol. 63 (2017)
  • Analysis of Link Asymmetry in Virtual Multiple-Input-Single-Output (VMISO)
    • Authors: Haejoon Jung; Mary Ann Weitnauer
      Pages: 20 - 29
      Abstract: Publication date: Available online 29 May 2017
      Source:Ad Hoc Networks
      Author(s): Haejoon Jung, Mary Ann Weitnauer
      Cooperative transmission (CT) is an effective technique to mitigate multi-path fading through spatial diversity. In CT, spatially separated wireless nodes collaborate to form a virtual multiple-input-single-output (VMISO) link, which provides signal-to-noise ratio advantage over the conventional single-input-single-output (SISO) communications. In this paper, we consider link asymmetry of the VMISO links between two neighboring CT clusters in wireless multi-hop networks. Link asymmetry is important because it impacts the performance of link and routing layer protocols. While most of the existing studies on CT simplify analysis on CT-based networks with co-located approximation that ignores disparate path losses in VMISO links by assuming co-located transmitting nodes, this paper presents the impact of disparate path losses on link asymmetry by allowing the relay locations to be random. Assuming exclusive signal detection by cluster heads, we identify two main causes of the VMISO link asymmetry, which do not appear in the conventional SISO-based networks: independent fading and path disparity. We evaluate the degree of link asymmetry in terms of three metrics: the power correlation, the power ratio, and the probability that the power gap is 3dB or higher. Also, the simulation results reveal how system parameters and channel conditions impact the VMISO link asymmetry.

      PubDate: 2017-06-01T17:35:40Z
      DOI: 10.1016/j.adhoc.2017.05.005
      Issue No: Vol. 63 (2017)
  • Location Based Transmission Using a Neighbour Aware with Optimized EIFS
           MAC for Ad Hoc Networks
    • Authors: Jims Marchang; Bogdan Ghita; David Lancaster
      Pages: 62 - 78
      Abstract: Publication date: Available online 3 June 2017
      Source:Ad Hoc Networks
      Author(s): Jims Marchang, Bogdan Ghita, David Lancaster
      In a typical Ad Hoc network, participating nodes have scarce shared bandwidth and limited battery life resources, so resource optimization and enhancing the overall network performance are the primary aims to maintain functionality. This paper proposes a new cross layer Medium Access Control (MAC) algorithm called Location Based Transmission using a Neighbour Aware with optimized Extended Inter-Frame Spacing (EIFS) for Ad Hoc Networks MAC (LBT-NA with optimized-EIFS MAC) that aims to reduce the transmission power when communicating with the next hop receiver based on node's location which is made available during node deployment. However, node mobility is not taken into account in the study of this paper. According to the algorithm the node dynamically adjusts its transmission power, if there is an active neighbour located beyond the communicating source and destination pair to avoid hidden nodes. The new protocol also defines an optimized EIFS when frame collision, frame error or frame capture takes place, in-order to maintain a fair channel access among the contending nodes. The proposed MAC also uses a modified range of random backoff values, based on the degree of contention unlike IEEE 802.11 series which uses a fixed random backoff value for fresh frames irrespective of the degree of contention. Simulation results indicate that in a random topology with a random source and destination, when the two sources are separated by a minimum distance of 200m, the performance gain of power controlled MAC over IEEE 802.11b ranges from 30% to 70% depending on the type of traffics in the network and the degree of fairness ranges from 62% to 99.99% for a location based MAC with minimum power transmission, whereas LBT-NA with optimized-EIFS MAC secures fairness index ranging from 75% to 99.99%. Communication with a node that is 20m away can save 40% of the battery life in comparison to the traditional transmission power MAC from 802.11b. The validation tests demonstrate that the proposed algorithm increases battery life and reduces the interference impact on shorter distance communication and increases the probability of parallel transmission. The proposed protocol also provides a scope for active nodes to transmit with a higher degree of probability, providing higher degree of overall network throughput in the environment and alleviate the starvation of hidden node by using Dynamic EIFS scheme.

      PubDate: 2017-06-06T18:59:33Z
      DOI: 10.1016/j.adhoc.2017.06.001
      Issue No: Vol. 63 (2017)
  • Improving charging capacity for wireless sensor networks by deploying one
           mobile vehicle with multiple removable chargers
    • Authors: Tao Zou; Wenzheng Xu; Weifa Liang; Jian Peng; Yiqiao Cai; Tian Wang
      Pages: 79 - 90
      Abstract: Publication date: August 2017
      Source:Ad Hoc Networks, Volume 63
      Author(s): Tao Zou, Wenzheng Xu, Weifa Liang, Jian Peng, Yiqiao Cai, Tian Wang
      Wireless energy transfer is a promising technology to prolong the lifetime of wireless sensor networks (WSNs), by employing charging vehicles to replenish energy to lifetime-critical sensors. Existing studies on sensor charging assumed that one or multiple charging vehicles being deployed. Such an assumption may have its limitation for a real sensor network. On one hand, it usually is insufficient to employ just one vehicle to charge many sensors in a large-scale sensor network due to the limited charging capacity of the vehicle or energy expirations of some sensors prior to the arrival of the charging vehicle. On the other hand, although the employment of multiple vehicles can significantly improve the charging capability, it is too costly in terms of the initial investment and maintenance costs on these vehicles. In this paper, we propose a novel charging model that a charging vehicle can carry multiple low-cost removable chargers and each charger is powered by a portable high-volume battery. When there are energy-critical sensors to be charged, the vehicle can carry the chargers to charge multiple sensors simultaneously, by placing one portable charger in the vicinity of one sensor. Under this novel charging model, we study the scheduling problem of the charging vehicle so that both the dead duration of sensors and the total travel distance of the mobile vehicle per tour are minimized. Since this problem is NP-hard, we instead propose a ( 3 + ϵ ) -approximation algorithm if the residual lifetime of each sensor can be ignored; otherwise, we devise a novel heuristic algorithm, where ϵ is a given constant with 0 < ϵ ≤ 1. Finally, we evaluate the performance of the proposed algorithms through experimental simulations. Experimental results show that the performance of the proposed algorithms are very promising.

      PubDate: 2017-06-11T19:30:02Z
      DOI: 10.1016/j.adhoc.2017.05.006
      Issue No: Vol. 63 (2017)
  • Predicting encounter and colocation events
    • Authors: Karim Karamat Jahromi; Matteo Zignani; Sabrina Gaito; Gian Paolo Rossi
      Pages: 11 - 21
      Abstract: Publication date: Available online 14 April 2017
      Source:Ad Hoc Networks
      Author(s): Karim Karamat Jahromi, Matteo Zignani, Sabrina Gaito, Gian Paolo Rossi
      Although an extensive literature has been devoted to mine and model mobility features, forecasting where, when and whom people will encounter/colocate still deserve further research efforts. Forecasting people’s encounter and colocation features is the key point for the success of many applications ranging from epidemiology to the design of new networking paradigms and services such as delay tolerant and opportunistic networks. While many algorithms which rely on both mobility and social information have been proposed, we propose a novel encounter and colocation predictive model which predicts user’s encounter and colocation events and their features by exploiting the spatio-temporal regularity in the history of these events. We adopt a weighted features Bayesian predictor and evaluate its accuracy on two large scales WiFi and cellular datasets. Results show that our approach could improve prediction accuracy w.r.t standard naïve Bayesian and some of the state of the art predictors.

      PubDate: 2017-04-18T20:27:05Z
      DOI: 10.1016/j.adhoc.2017.04.004
      Issue No: Vol. 62 (2017)
  • Cognitive Channel Selection and Scheduling for Multi-Channel Dynamic
           Spectrum Access Networks Considering QoS Levels
    • Authors: Gulnur Selda Uyanik; Sema Oktug
      Pages: 22 - 34
      Abstract: Publication date: Available online 12 April 2017
      Source:Ad Hoc Networks
      Author(s): Gulnur Selda Uyanik, Sema Oktug
      Dynamic spectrum access (DSA) networks are composed of unprivileged users, called secondary users (SUs), that utilize the spectrum opportunities produced by the absence of co-located privileged primary users (PUs) via their cognitive capabilities. Providing a certain level of quality of service (QoS) to these users is a very challenging problem whilst providing protection to licensed PUs and contenting with nearby SUs. Even though centralized solutions may lead to better solutions in terms of network efficiency, the dynamic nature of DSA networks make the distributed solution approaches more attractive. In this paper, we present a fast, distributed, PU temporal-activity-estimation-aided spectrum assignment scheme for a multi-channel DSA system, including several multi-interface capable SUs with traffic demands at differentiated QoS levels. We first developed the proposed cognitive channel selection method, considering a simplified network having single channel and investigated its performance. Second, considering multi-channel environment, along with contending multi-SUs each of which can utilize multiple channels using their multi-interface property, we adopted the designed algorithm and coupled the proposed spectrum selection scheme with a distributed spectrum sharing mechanism that we devised to increase the overall network utility further. We modeled our scheme along with the network model using MATLAB® and evaluated its performance via several simulations. The extensive simulations validate the effectiveness of the proposed channel assignment scheme in terms of the Figure of Merit we defined, composed of the weighted sum of the throughput ratio values for packets of different QoS levels that successfully reached at the destination. The results also show the superior performance of the proposed scheme with respect to a native scheme that utilizes every spectrum opportunity in favor of the most demanding traffic flow.

      PubDate: 2017-04-18T20:27:05Z
      DOI: 10.1016/j.adhoc.2017.04.003
      Issue No: Vol. 62 (2017)
  • Capacity and contention-based joint routing and gateway selection for
           machine-type communications
    • Authors: Muhammad Omer Farooq; Cormac J. Sreenan; Kenneth N. Brown
      Pages: 35 - 49
      Abstract: Publication date: July 2017
      Source:Ad Hoc Networks, Volume 62
      Author(s): Muhammad Omer Farooq, Cormac J. Sreenan, Kenneth N. Brown
      Typically, in machine-type communications (MTC) devices communicate with servers over the Internet. In a large-scale machine-to-machine area (M2M) network, the devices may not connect directly to the Internet due to radio transmission and energy limitations. Therefore, the devices collaborate wirelessly to relay their data to a gateway. A large-scale M2M area network may have multiple gateways, selecting a proper gateway for the devices can have immense impact on the network’s performance. We present the channel capacity and contention-based joint routing and gateway selection methods for MTC. Based on channel capacity and contention, our methods select the best gateway on per-packet, per-flow, and per-node basis. We compare the methods’ performance with existing methods using simulation and test-bed experiments. We analyse the impact of the number of gateways, physical distribution of transmitters, control overhead, and duty-cycling on the performance of the gateway selection methods. Our results demonstrate that, in duty-cycled operations, the methods’ performance depends on control overhead and making a good trade-off between load imbalance to different gateways and a forwarding path’s length. Otherwise only the latter impacts the methods’ performance. In general, our node-based best gateway selection method makes a better trade-off and exhibits lower control overhead, hence it demonstrates better performance. Moreover, our methods demonstrate better performance as compared to an existing state-of-the-art joint routing and gateway selection method.

      PubDate: 2017-04-25T20:56:08Z
      DOI: 10.1016/j.adhoc.2017.04.006
      Issue No: Vol. 62 (2017)
  • Reliable delay-sensitive spectrum handoff management for re-entrant
           secondary users
    • Abstract: Publication date: November 2017
      Source:Ad Hoc Networks, Volume 66
      Author(s): Uthpala Subodhani Premarathne, Ibrahim Khalil, Mohammed Atiquzzaman
      Opportunistic data transmissions in cognitive radio networks is an effective data transmission mechanism which reduces the limitations of fixed spectrum allocations. In cognitive radio networks secondary users (SUs) can transmit over the available spectrum when the primary users (PUs) are inactive. However, a SU may get interrupted over multiple times when the PU re-appear on that channel for data transmission. For an interrupted SU, efficient spectrum hand-off management is vital to complete the data transmission. Efficient spectrum hand-off necessitates greatly for delay sensitive data transmissions (e.g. time critical remote monitoring applications). For such data transmissions, delay sensitive spectrum hand-off mechanisms are necessary. However, the existing sensed spectrum hand-off management methods do not consider delay bounded repeated attempts for spectrum reallocation when there are multiple interruptions. In this paper a delay sensitive spectrum hand-off management for the re-entrant SUs due to multiple interruptions is proposed. Compared to the existing solutions, the proposed spectrum allocation strategy offers more reliable delay-tolerant opportunities for accessing the spectrum for the re-entrant SUs.

      PubDate: 2017-09-17T13:12:48Z
  • Geographic Routing and Hole Bypass using Long Range Sinks for Wireless
           Sensor Networks
    • Authors: Moysés M. Lima; Horácio A.B.F. Oliveira; Daniel L. Guidoni; Antonio A.F. Loureiro
      Abstract: Publication date: Available online 6 September 2017
      Source:Ad Hoc Networks
      Author(s): Moysés M. Lima, Horácio A.B.F. Oliveira, Daniel L. Guidoni, Antonio A.F. Loureiro
      Greedy Forward is a well-known technique used by most of the geographic routing algorithms to forward packets to the node that is geographically closer to the destination node. It is the simplest form of the proposed geographic routing algorithms and it is particularly attractive in sensor networks by bringing additional advantages such scalability, dynamism, and high delivery rates. However, in the presence of a hole (or voids), greedy forward techniques tend to fail. Thus, a hole bypass solution needs to be used in order to route packets to a node where greedy forwarding process can be resumed. In this work, we propose a new geographic routing algorithm called REACT that can bypass routing holes and create routing paths toward the sink node. Our solution takes advantage of the higher communication range of the sink node and the Received Signal Strength Indicator (RSSI) to enable the construction of routing paths by self-electing the next hop at each step while also performing data aggregation. No extra packets are required to configure the routing task. Our results clearly show an efficient data delivery achieved by the proposed algorithm in scenarios with routing holes with all the benefits of a greedy forwarding technique.

      PubDate: 2017-09-11T12:49:24Z
      DOI: 10.1016/j.adhoc.2017.08.010
  • Approximate Cardinality Estimation (ACE) in Large-Scale Internet of Things
    • Authors: Qing Cao; Yunhe Feng; Zheng Lu; Hairong Qi; Leon Tolbert; Lipeng Wan; Zhibo Wang; Wenjun Zhou
      Abstract: Publication date: Available online 26 August 2017
      Source:Ad Hoc Networks
      Author(s): Qing Cao, Yunhe Feng, Zheng Lu, Hairong Qi, Leon Tolbert, Lipeng Wan, Zhibo Wang, Wenjun Zhou
      IoT (Internet of Things) deployments have been used in many diverse applications in increasingly large numbers, usually composed of embedded sensors, computational units, and actuators. One central problem with IoT applications is that we frequently need to query the number of nodes according to certain requirements, or filters. For example, a user may want to query the number of nodes that are currently actively sensing data, or having data above a threshold. Conventional methods typically require each active node to report their status, leading to a total communication overhead that is at least proportional to the network size. In this paper, we study the problem of deployment size estimation by investigating probabilistic methods for processing queries, where we only try to obtain approximate estimates within desired confidence intervals. Our methods are different with other probabilistic methods, such as sampling, in that our approach is based on the well-known birthday paradox in statistics. Hence, our methods provide a different solution that can be combined or used to enhance existing methods. We demonstrate through extensive simulations that their overhead is considerably lower than conventional methods, usually by an order of magnitude.

      PubDate: 2017-08-27T15:13:13Z
      DOI: 10.1016/j.adhoc.2017.08.009
  • Convergecast in Wireless Body Area Networks
    • Authors: Wafa Badreddine; Nesrine Khernane; Maria Potop-Butucaru; Claude Chaudet
      Abstract: Publication date: Available online 24 August 2017
      Source:Ad Hoc Networks
      Author(s): Wafa Badreddine, Nesrine Khernane, Maria Potop-Butucaru, Claude Chaudet
      Wireless Body Area Networks (WBAN) is a recent challenging area in the health monitoring domain. There are several concerns in this area ranging from energy efficient communication to designing delays efficient protocols that support nodes dynamicity induced by human body mobility. This paper focuses on the convergecast or data gathering protocols in WBAN. Our contribution is twofold. First, we extensively analyze the impact of postural body mobility on various classes of multi-hop convergecast strategies. Our study does not limit itself to the existing state-of-the-art in WBAN, we adapted to WBAN settings strategies from the areas of Delay Tolerant Networks (DTN) and Wireless Sensor Networks (WSN). We evaluate these strategies in terms of resilience to the human mobility, end-to-end delay and energy consumption, via the OMNeT++ simulator that we enriched with a realistic channel model issued from the recent research on biomedical and health informatics. Our simulations show that strategies that perform well in DTN and WSN cannot be just extrapolated to WBAN without a deeper investigation. That is, existing convergecast strategies for DTN or WSN do not perform well with postural body movements because of the topological partitioning provoked by important link attenuations due to signal obstructions either by clothes or by the body itself. Secondly, our extensive simulations give us valuable insights and directions for designing a novel convergecast strategy for WBAN called Hybrid that presents a good compromise in terms of resiliency to mobility, end-to-end delay and energy consumption.

      PubDate: 2017-08-27T15:13:13Z
      DOI: 10.1016/j.adhoc.2017.08.008
  • On State Maintenance in Cluster-Based Mobile Ad-hoc Networks
    • Authors: Amit Banerjee; Chung-Ta King; Hung-Chang Hsiao
      Abstract: Publication date: Available online 24 August 2017
      Source:Ad Hoc Networks
      Author(s): Amit Banerjee, Chung-Ta King, Hung-Chang Hsiao
      Clustering is an effective strategy for tackling the dynamics and scalability in a large-scale mobile ad hoc networks (MANETs). However, the mobility of the nodes makes it very difficult to maintain the states of the clusters, such as connectivity between clusters, available bandwidth, and node membership. A good maintenance scheme should balance the workload and power consumption of the nodes, incur little overhead, and track the changes timely and accurately. For this, we consider the implementation of a maintenance sublayer to handle the dynamic state of the clusters. The idea is to hide the dynamics of the underlying clusters, to improve the performance of applications in MANET. In this paper, we examine the design space of the state maintenance problem in cluster-based MANETs. At one end, we study a fully distributed approach, called Cluster-Based WithOut Head Overlay (CWOHO). At the other end, we consider the strategy that uses cluster heads to handle the maintenance operations, called Cluster-Based With Head Overlay (CWHO). In-between two extremes, we investigate a third possibility, called Clusters with Neighbor Information (CNI). We provide an in-depth and comprehensive study of these strategies under various network conditions and mobility models. Our experimental evaluation shows that the data delivery ratio of CWOHO is at least 7% more than CWHO, under increasing node mobility and number of clusters. However, the reverse is true for the control overhead.

      PubDate: 2017-08-27T15:13:13Z
      DOI: 10.1016/j.adhoc.2017.08.007
  • Compressive Detection and Localization of Multiple Heterogeneous Events in
           Sensor Networks
    • Authors: Ruobing Jiang; Yanmin Zhu; Tong Liu; Qiuxia Chen
      Abstract: Publication date: Available online 2 August 2017
      Source:Ad Hoc Networks
      Author(s): Ruobing Jiang, Yanmin Zhu, Tong Liu, Qiuxia Chen
      This paper focuses on the comprehensive event detection and localization problem which efficiently detects not only the number and the position, but also the event signal strength of events in sensor networks. We consider the practical situation where multiple events may simultaneously occur, their signal with heterogeneous strength attenuates over distance and their signal propagation region may overlap. The problem becomes even more challenging when we get rid of the commonly made impractical assumptions, such as the oversimplified binary detection model, the awareness of the number and potential positions of future events, and the existing of super sensor nodes with unlimited sensing range. Inspired by spatially sparse event occurrences, we propose the efficient compressive sensing based approach called CED. Instead of collecting complete sensor readings, our self-driven and fully distributed measurement construction process makes only a small number of qualified measurements, enabling compressive sensing based data recovery. The distinguishing feature of our approach is that it requires no knowledge of, and is adaptive to, the number of occurred events which is changing over time. We have validated signal attenuation model of real-world events and implemented the proposed approach on a testbed of 36 TelosB motes. Testbed experiments and simulation results jointly demonstrate that our approach can achieve high detection rate with event occurred grids while incurring modest transmission overhead.

      PubDate: 2017-08-03T11:34:09Z
      DOI: 10.1016/j.adhoc.2017.08.001
  • Performance Analysis of Superior Selective Reporting-based Energy
           Efficient Cooperative Spectrum Sensing in Cognitive Radio Networks
    • Authors: Rajalekshmi Kishore; Ramesha C.K.; Sanjeev Gurugopinath; K.R. Anupama
      Abstract: Publication date: Available online 1 August 2017
      Source:Ad Hoc Networks
      Author(s): Rajalekshmi Kishore, Ramesha C.K., Sanjeev Gurugopinath, K.R. Anupama
      We study the energy efficiency of superior selective reporting-based schemes for spectrum sensing in cognitive radio networks. We first consider the superior selective reporting (SSR) scheme proposed earlier in the literature, and derive the achievable throughput, energy consumption and energy efficiency (EE) of the SSR scheme. We propose the maximization of EE for the SSR scheme as a multiple variable-based, non-convex optimization problem and provide approximations to reduce it to a quasi-convex optimization. We highlight that the errors due to these approximations are negligible. The SSR scheme is designed to optimize the energy consumption, which enhances the EE. Alternatively, EE can be improved by increasing the achievable throughput. Towards this end, we propose a novel variation on the SSR scheme called the opportunistic SSR (OSSR) scheme, and carry out its EE analysis. We study the tradeoff between performances of the SSR and OSSR schemes – the implicit tradeoff between achievable throughput and energy consumption, and discuss the regimes where OSSR is preferred over SSR and vice-versa, in terms of the EE. Also, through an extensive numerical study, we show that both schemes outperform the conventional schemes that employ the OR and AND fusion rules, in terms of energy efficiency.

      PubDate: 2017-08-03T11:34:09Z
      DOI: 10.1016/j.adhoc.2017.07.010
  • Simulation of control loops in wireless networks: relating QoS with QoC
    • Authors: Sergio R.M. Canovas; Carlos E. Cugnasca; Cíntia B. Margi
      Abstract: Publication date: Available online 25 July 2017
      Source:Ad Hoc Networks
      Author(s): Sergio R.M. Canovas, Carlos E. Cugnasca, Cíntia B. Margi
      Considering the flexibility of network-based control systems and the wide adoption of wireless IP networks, the relationship between Quality of Service (QoS) and Quality of Control (QoC) parameters is studied in a simple control loop implemented over a wireless ad hoc network. This relationship is investigated using ns-2 simulator in three scenarios: static without packet loss, static with packet loss and mobile. The first scenario was compared to a case study for wired networks presented in the literature. Similar results were obtained, according to the prediction that different packet-switched technologies would present similar results because the concepts of QoS parameters are general enough. Results related to the other two scenarios qualitatively show QoC problems that appear due to the high utilization rate of the network and route disruption due to mobility. These problems can be summarized by the “inertia” of the controlled variable. A proof-of-concept experiment was also implemented to complement and to evaluate simulations.

      PubDate: 2017-08-03T11:34:09Z
      DOI: 10.1016/j.adhoc.2017.07.008
  • Optimal Energy Aware Clustering in Circular Wireless Sensor Networks
    • Authors: Mahdi Arghavani; Mohammad Esmaeili; Maryam Esmaeili; Farzad Mohseni
      Abstract: Publication date: Available online 25 July 2017
      Source:Ad Hoc Networks
      Author(s): Mahdi Arghavani, Mohammad Esmaeili, Maryam Esmaeili, Farzad Mohseni
      The lifetime of a wireless sensor node refers to the duration after which the node's energy has ended. Since battery replacement in most applications of wireless sensor networks is not possible, designing an energy-efficient communication protocol in these networks is very important. Therefore, many studies have been conducted to find a solution to increase the lifetime of these networks. Clustering is a useful technique for partitioning the network to areas, called clusters and entrusting energy-waste issues (e.g. data gathering, aggregating and routing to the sink) to some specific nodes, the cluster heads. In this paper, a new method for Optimal Clustering in Circular Networks (OCCN) is proposed which aims to mitigate energy consumption and increase the lifetime of wireless sensor networks. In this method, which is proposed for a circular area surrounding a sink, one hop communication between the cluster heads and the sink is replaced by an optimal multi-hop communications. Moreover, the optimal number of clusters is computed and the energy consumption is optimized by partitioning the network into nearly the same size clusters in a distributed manner. Simulation results indicate that the proposed method achieved more than 35% improvements in terms of energy consumption in comparison to other well-known clustering techniques.

      PubDate: 2017-08-03T11:34:09Z
      DOI: 10.1016/j.adhoc.2017.07.006
  • Cooperative Resynchronization to Improve the Reliability of Colocated
           IEEE 802.15.4 -TSCH Networks in Dense Deployments
    • Authors: Sahar Ben Yaala; Fabrice Théoleyre; Ridha Bouallegue
      Abstract: Publication date: Available online 11 July 2017
      Source:Ad Hoc Networks
      Author(s): Sahar Ben Yaala, Fabrice Théoleyre, Ridha Bouallegue
      With the large adoption of small and smart objects, the interest of researchers to define new protocols to meet Internet of Things (IoT) requirements is growing. In particular, the Industrial Internet of Things (IIoT) aims to provide high reliability and upper bounded end-to-end latency while interconnecting a large collection of sensors and actuators. The TimeSlotted Channel Hopping (TSCH) mode of IEEE 802.15.4 exploits a slow channel hopping approach to combat efficiently external interference (e.g. Wi-Fi, Bluetooth). We envision in the future very dense deployments and we investigate here the mutual influence among different colocated TSCH networks. We first study analytically with a simple model the performance of several TSCH networks, able or not to be synchronized with each other. We emphasize the multiplication of collisions, exacerbated by clock drifts when no cooperation is achieved. We also highlight experimentally that a mutual synchronization improves very significantly the reliability. We propose here a mechanism to re-synchronize distributively the border routers of different TSCH networks. Our thorough experimental evaluation illustrates the relevance of our approach, able to guarantee high-reliability, even in very dense topologies.

      PubDate: 2017-07-12T02:45:45Z
      DOI: 10.1016/j.adhoc.2017.07.002
  • On the performance of adaptive coding schemes for energy efficient and
           reliable clustered wireless sensor networks
    • Authors: Imad Ez-zazi; Mounir Arioua; Ahmed El Oualkadi; Pascal Lorenz
      Abstract: Publication date: Available online 8 July 2017
      Source:Ad Hoc Networks
      Author(s): Imad Ez-zazi, Mounir Arioua, Ahmed El Oualkadi, Pascal Lorenz
      Clustering is the key for energy constrained wireless sensor networks (WSNs). Energy optimization and communication reliability are the most important consideration in designing efficient clustered WSN. In lossy environment, channel coding is mandatory to ensure reliable and efficient communication. This reliability is compromised by additional energy of coding and decoding in cluster heads. In this paper, we investigated the trade-off between reliability and energy efficiency and proposed adaptive FEC/FWD and FEC/ARQ coding frameworks for clustered WSNs. The proposed schemes consider channel condition and inter-node distance to decide the adequate channel coding usage. Simulation results show that both the proposed frameworks are energy efficient compared to ARQ schemes and FEC schemes, and suitable to prolong the clustered network lifespan as well as improve the reliability.

      PubDate: 2017-07-12T02:45:45Z
      DOI: 10.1016/j.adhoc.2017.07.001
  • PACK: Path Coloring based k-Connectivity Detection Algorithm for Wireless
           Sensor Networks
    • Authors: Orhan Dagdeviren; Vahid Khalilpour Akram
      Abstract: Publication date: Available online 21 June 2017
      Source:Ad Hoc Networks
      Author(s): Orhan Dagdeviren, Vahid Khalilpour Akram
      A k-connected wireless sensor network (WSN) can tolerate failures on k-1 arbitrary nodes without loosing the connectivity between the remaining active nodes. Hence, the k value is one of the useful benchmarks that can help to measure the network reliability. Given that the nodes in a k-connected network has at least k disjoint paths to each other, we propose the path coloring based k -connectivity detection algorithm (PACK) that finds the k by counting the disjoint paths between the sink and all other nodes. The proposed algorithm has two Detection and Notification phases. In the Detection phase, all nodes find their disjoint paths to the sink and in the Notification phase the minimum detected path count, which determines the global k, is sent to the sink node. We theoretically prove that the detection range of our proposed algorithm is better than the existing distributed algorithms and uses fixed length messages with O(nΔlog 2 n) bit complexity and O(n) time complexity where n is the number of nodes and Δ is the maximum node degree. According to the comprehensive simulation results, the average correct detection ratio of proposed algorithm is more than 91% which is at least 2.3 times higher than the existing algorithms.

      PubDate: 2017-06-21T21:25:23Z
      DOI: 10.1016/j.adhoc.2017.06.005
  • A Distributed Multi-path Routing Algorithm to Balance Energy Consumption
           in Wireless Sensor Networks
    • Authors: A. Laouid; A. Dahmani; A. Bounceur; R. Euler; F. Lalem; A. Tari
      Abstract: Publication date: Available online 21 June 2017
      Source:Ad Hoc Networks
      Author(s): A. Laouid, A. Dahmani, A. Bounceur, R. Euler, F. Lalem, A. Tari
      A large use of applications of Wireless Sensor Networks (WSNs) pushes researchers to design and improve protocols and algorithms against the encountered challenges. One of the main goals is data gathering and routing to the base station (through the sink nodes) with lack of acknowledgement and where each node has no information about the network. Unbalanced energy consumption during the data routing process is an inherent problem in WSNs due to the limited energy capacity of the sensor nodes. In fact, WSNs require load balancing algorithms that make judicious use of the limited energy resource to route the gathered data to the sink node. In this paper, we propose a balanced multi-path routing algorithm by focusing on the residual energy and the hop count of each node to discover the best routes and to insert them into the routing table. The main idea of this algorithm comes from Ant Colony Optimization (ACO) and automata network modelization. Hence, the potential performance of the proposed algorithm relies on the best route to be selected which should have the minimum number of hops, the maximum energy and weighted energy between participating nodes to extend the lifetime of the network.

      PubDate: 2017-06-21T21:25:23Z
      DOI: 10.1016/j.adhoc.2017.06.006
  • Cost-Effective Barrier Coverage Formation in Heterogeneous Wireless Sensor
    • Authors: Zhibo Wang; Qing Cao; Hairong Qi; Honglong Chen; Qian Wang
      Abstract: Publication date: Available online 20 June 2017
      Source:Ad Hoc Networks
      Author(s): Zhibo Wang, Qing Cao, Hairong Qi, Honglong Chen, Qian Wang
      Barrier coverage is a critical issue in wireless sensor networks (WSNs) for security applications, which however cannot be guaranteed to be formed after initial random deployment of sensors. Existing work on barrier coverage mainly focus on homogeneous WSNs, while little effort has been made on exploiting barrier coverage formation in heterogeneous WSNs where different types of sensors are deployed with different sensing models and costs. In this paper, we study how to efficiently form barrier coverage by leveraging multiple types of mobile sensors to fill in gaps between pre-deployed stationary sensors in heterogeneous WSNs. The stationary sensors are grouped into clusters and a cluster-based directional barrier graph is proposed to model the barrier coverage formation problem. We prove that the minimum cost of mobile sensors required to form a barrier with stationary sensors is the length of the shortest path on the graph. Moreover, we propose a greedy movement algorithm for heterogeneous WSNs to efficiently schedule different types of mobile sensors to different gaps while minimizing the total moving cost. In particular, we formulate the movement problem for homogeneous WSNs as a minimum cost bipartite assignment problem, and solve it in polynomial time using the Hungarian algorithm. Extensively experimental results on homogeneous and heterogeneous WSNs demonstrate the effectiveness of the proposed algorithms.

      PubDate: 2017-06-21T21:25:23Z
      DOI: 10.1016/j.adhoc.2017.06.004
  • Lightweight and Efficient Privacy-Preserving Data Aggregation Approach for
           the Smart Grid
    • Authors: Mohamad Badra; Sherali Zeadally
      Abstract: Publication date: Available online 16 June 2017
      Source:Ad Hoc Networks
      Author(s): Mohamad Badra, Sherali Zeadally
      – Over the last few years, we have seen the emergence of a wide range of Smart Grid architectures, technologies, and applications made possible by the significant improvements in hardware, software, and networking technologies. One of the challenges that has emerged in the Smart Grid environment is the privacy of Smart Grid users. Although several privacy-preserving techniques have been proposed recently for the Smart Grid environment, many of them suffer from high computation and communication costs, different types of attacks, and the use of complex key management schemes. To address these drawbacks, we propose an efficient, lightweight privacy-preserving data aggregation approach that makes use of symmetric homomorphic encryption and Diffie-Hellman (DH) or Elliptic Curve Diffie-Hellman (ECDH) key exchange methods. In contrast to previously proposed privacy-preserving schemes for the Smart Grid, we demonstrate the superiority of our proposed approach in terms of its low transmission and message overheads, and resiliency against a wide range of session key attacks, and ability to maintain data integrity against unauthorized modification or data forgery and to ensure authenticity of smart meters’ data.

      PubDate: 2017-06-16T20:23:58Z
  • Location-aware Interest-related Micro-cloud Topology Construction and
           Bacteria Foraging-based Offloading Strategy
    • Authors: Li Chunlin; Zhu Liye; Luo Youlong
      Abstract: Publication date: Available online 15 June 2017
      Source:Ad Hoc Networks
      Author(s): Li Chunlin, Zhu Liye, Luo Youlong
      Micro-cloud, as one kind of mobile cloud computing modes, can reduce network delay and alleviate resource constraint of mobile devices. In this mode, mobile devices use their idle resources to provide services for others. Due to the mobility, irregularity of mobile devices, the stability problem of micro-cloud environment still remains challenging. In order to increase the stability of micro-cloud and decrease network delay, the interest-related and location-aware micro-cloud topology is proposed in this paper. The interest-related mobile device nodes are classified into the same micro-cloud which can raise the probability of resource reuse. For reducing failed requests and enhancing the scalability of micro-cloud topology, both node location and node service capacity are considered. Moreover, the bacteria foraging-based offloading algorithm for interest-related micro-cloud topology is proposed, which is an energy-efficient and response time constraint offloading approach. The experiments are conducted and the experiment results show that the location-aware interest-related micro-cloud topology has better stability and scalability, while the bacteria foraging-based offloading algorithm performs better in terms of reducing response time and energy.

      PubDate: 2017-06-16T20:23:58Z
      DOI: 10.1016/j.adhoc.2017.06.002
  • On the using of discrete wavelet transform for physical layer key
    • Authors: Furui Zhan; Nianmin Yao
      Abstract: Publication date: Available online 15 June 2017
      Source:Ad Hoc Networks
      Author(s): Furui Zhan, Nianmin Yao
      For key generation between wireless transceivers, key generation leveraging channel reciprocity is a promising alternative to public key cryptography. Several existing schemes have validated its feasibility in real environments. However, in some scenarios, channel measurements collected by the involved transceivers are highly correlated but not identical, i.e., measurement sequences of these transceivers have too many discrepancies, which makes it difficult to extract the shared key from these measurements. In this paper, we propose a scheme to achieve secret key generation from wireless channels. During the proposed scheme, to reduce the amount of the referred discrepancies and further achieve efficient key generation, the involved transceivers separately apply a compressor based on the discrete wavelet transform (DWT) to pre-process their measurements. Then, multi-level quantization is implemented to quantify the output of DWT-based compressor. An encoding scheme based on gray code is employed to establish bit sequence and ensure that the resulting bit mismatch rate can be further reduced so that efficient information reconciliation can be implemented. Accordingly, the shared key between these transceivers can be derived after information reconciliation. Finally, 2-universal hash functions are used to guarantee the randomness of the shared secret key. Several experiments in real environments are conducted to validate the proposed scheme. The results demonstrate that the proposed scheme is available to generate secret keys between transceivers even though their measurement sequences have too many discrepancies.

      PubDate: 2017-06-16T20:23:58Z
      DOI: 10.1016/j.adhoc.2017.06.003
  • Multi-constraints Link Stable Multicast Routing Protocol in MANETs
    • Authors: Gaurav Singal; Vijay Laxmi; M.S. Gaur; Swati Todi; Vijay Rao; Meenakshi Tripathi; Riti Kushwaha
      Abstract: Publication date: Available online 8 June 2017
      Source:Ad Hoc Networks
      Author(s): Gaurav Singal, Vijay Laxmi, M.S. Gaur, Swati Todi, Vijay Rao, Meenakshi Tripathi, Riti Kushwaha
      In MANETs, real-time multimedia applications make Quality of Service (QoS) support, a crucial issue regarding terms of increased throughput, reduced jitter, and available bandwidth. Most of the existing routing protocols focus on straight forward hop-count metric and are less adaptable to densely distributed and highly mobile networks. Therefore, Multicast communication with QoS in densely populated highly dynamic network an exciting research challenges. The objective of the present paper is to introduce a QoS aware routing metric that determines a reliable forwarding node based on Link Stability cost Function (LSF). A mesh of Multicast routes between Multicast source and destinations has been established using nodes with a maximum LSF. The principle theme underlying our protocol is optimum contention count that can be estimated with the help of received signal strength. The proposed protocol comprises the following stages:(1) Calculation of Link Stability Factor (2) Determination of maximum LSF value (3) Pruning adjacent nodes (4) Creation of a mesh consisting of more stable forwarding nodes (5) Creation of a mobile network in which no node remains isolated, as well as nodes, face lesser contention. Our proposed protocol has been demonstrated on an existing mesh-based Multicast routing protocols, ODMRP. Simulations are carried out on Exata/Cyber simulator, and obtained results are compared with that of ODMRP. The comparative analysis reveals that our protocol is more efficient in contrast to ODMRP, LSMRP, and MMRNS, regarding performance parameters like Packet Delivery Ratio (PDR), Average End-to-End Latency and Average Route Lifetime. Also, we have analyzed the impact of minimum and maximum contention count on PDR and delay.

      PubDate: 2017-06-11T19:30:02Z
      DOI: 10.1016/j.adhoc.2017.05.007
  • Lightweight Power Control for Energy–Utility Optimization in
           Wireless Networks
    • Authors: Konstantinos P. Tsoukatos; Anastasios Giannoulis
      Abstract: Publication date: Available online 7 June 2017
      Source:Ad Hoc Networks
      Author(s): Konstantinos P. Tsoukatos, Anastasios Giannoulis
      We consider an interference-limited, ad-hoc wireless network in the high SINR regime and address the optimization of network utility and energy efficiency by cross–layer network control. Unlike the typical complex approach that requires solving a scheduling, routing and power control problem at each time slot, we propose running a single iteration of a gradient power control algorithm towards the optimal power allocation, together with backpressure multipath routing and flow control. Despite the fact that the respective optimizations at each time slot are never fully solved, we prove, under a high SINR assumption, that the proposed updates suffice to optimize network utility and energy efficiency. Main components of the joint algorithm are flow control at each node (based on local queues), backpressure routing/scheduling, and power control driven by backlog, interference, and power cost related information. We provide simulation results that illustrate the convergence to the optimal flow rates and link powers, compare against related algorithms from the literature, and examine the validity of the high SINR approximation. Our approach may allow in-practice performance gains and inspire more research on low-complexity, practical network control.

      PubDate: 2017-06-11T19:30:02Z
      DOI: 10.1016/j.adhoc.2017.05.010
  • Channel Quality Aware Cross-Layer Design based Rate Adaptive MAC for
           Improving the Throughput Capacity of Multi-hop Ad hoc Networks
    • Authors: Prasanna J. Shete; R.N. Awale; Satish Y. Ket
      Abstract: Publication date: Available online 30 May 2017
      Source:Ad Hoc Networks
      Author(s): Prasanna J. Shete, R.N. Awale, Satish Y. Ket
      In this paper we address the goal of achieving higher throughput capacity in multi-hop wireless ad hoc networks than estimated by capacity scaling laws of [Gupta and Kumar, 2000]. By exploiting the implications pointed in earlier research, a cross-layer design based channel quality aware rate adaptive MAC algorithm CQRA-MAC is proposed to achieve this goal. CQRA-MAC dynamically switches the MAC transmission rate on the basis of channel quality experienced at the physical layer. The proposed algorithm is implemented by modifying the IEEE 802.11 model of Qualnet 4.5 simulator and its performance is evaluated in static and mobile network scenarios following the random access transport capacity approach. Experimental results show that CQRA-MAC achieves higher throughput than DCF and ARF. The achieved throughput capacity is quantified in terms of measurable network parameters and thus validates equations of random access transport capacity framework [Andrews, Weber, Kountouris and Haenggi, 2010].

      PubDate: 2017-06-01T17:35:40Z
      DOI: 10.1016/j.adhoc.2017.05.009
  • An Efficient Protocol for Load-Balanced Multipath Routing in Mobile Ad Hoc
    • Authors: Ansuman Bhattacharya; Koushik Sinha
      Abstract: Publication date: Available online 30 May 2017
      Source:Ad Hoc Networks
      Author(s): Ansuman Bhattacharya, Koushik Sinha
      In this paper, we propose a new routing protocol called the Least Common Multiple based Routing (LCMR) for load-balanced multipath routing in Mobile Ad hoc NETworks (MANETs). First, we find multiple paths between a source to a destination, when those exist, along with the estimates of the time to route a packet along each of these paths. The data packets originating from the source to the destination are then distributed along these multiple paths in such a way that the number of data packets sent along any such path is inversely proportional to the routing time through this path. This distribution strategy keeps the load balanced along all the paths so that the overall routing time for sending the data packets is minimized. Routes between a given source-destination pair are discovered in a way similar to that in the Ad hoc On-demand Distance Vector (AODV) routing protocol with the difference that instead of the number of hops, the routing time for reaching the destination along every route is measured, and multiple routes, if those exist, will also be determined by the route discovery process. Our proposed technique for distribution of packets along different routes is very elegant with a better performance than the existing load-balanced routing protocols like Fibonacci Multipath Load Balancing (FMLB) and Multiple AODV (MAODV), as established from a theoretical analysis as well as through simulation results.

      PubDate: 2017-06-01T17:35:40Z
      DOI: 10.1016/j.adhoc.2017.05.008
  • A New Maximum Fault-tolerance Barrier-coverage Problem in Hybrid Sensor
           Network and Its Polynomial Time Exact Algorithm
    • Authors: Donghyun Kim; Yeojin Kim; Deying Li; Jungtaek Seo
      Abstract: Publication date: Available online 22 May 2017
      Source:Ad Hoc Networks
      Author(s): Donghyun Kim, Yeojin Kim, Deying Li, Jungtaek Seo
      This paper introduces a new maximum fault-tolerance barrier-coverage problem in hybrid sensor network, which consists of a number of both static ground sensors and fully-controllable mobile sensors. The problem aims to relocate the mobile sensor nodes so that the fault-tolerance of the barrier-coverage of the hybrid sensor network is maximized. The main contribution of this paper is the polynomial time exact algorithm for this new problem.

      PubDate: 2017-05-22T12:52:34Z
      DOI: 10.1016/j.adhoc.2017.05.004
  • Reliable Data Dissemination Protocol for VANET Traffic Safety Applications
    • Authors: Renê Oliveira; Carlos Montez; Azzedine Boukerche; Michelle S. Wangham
      Abstract: Publication date: Available online 19 May 2017
      Source:Ad Hoc Networks
      Author(s): Renê Oliveira, Carlos Montez, Azzedine Boukerche, Michelle S. Wangham
      In vehicular ad hoc networks (VANETs), cooperation between nodes is needed for proper performance of safety and traffic efficiency applications. A non-trivial scientific challenge in VANETs is the design of an adaptive broadcast protocol, which can provide efficient and end-to-end reliable warning messages dissemination. Usually, broadcast protocols for VANETs use beacon messages, disseminated among the vehicles, in order to get neighborhood information. When the vehicles are next to each other trying to broadcast at the same time, this may lead to frequent contention, and broadcast storms. On the other hand, in sparse density scenarios, vehicles have to face with failures in the message delivery. In this paper, we propose a novel protocol, Adaptive Data Dissemination Protocol (AddP), which aims at providing reliability to message dissemination in an efficient way. The protocol uses different mechanisms to dynamically adjust the beacon periodicity and to reduce the number of messages and beacons in the network. The effectiveness of our proposed protocol and the impacts of the use of the protocol by a VANET safety application were evaluated through experiments with network and traffic simulators.

      PubDate: 2017-05-22T12:52:34Z
      DOI: 10.1016/j.adhoc.2017.05.002
  • Energy efficient context aware traffic scheduling for IoT applications
    • Authors: Bilal Afzal; Sheeraz A. Alvi; Ghalib A. Shah; Waqar Mahmood
      Abstract: Publication date: Available online 5 May 2017
      Source:Ad Hoc Networks
      Author(s): Bilal Afzal, Sheeraz A. Alvi, Ghalib A. Shah, Waqar Mahmood
      The evolution of Internet of Things (IoT) has increased the appetite for the energy efficient wireless infrastructures. Most of the IoT devices are inherently resource constrained and heterogeneous in respect of their traffic demand. Moreover, these devices need to be made adaptable to the varying environmental conditions. However, existing traffic scheduling and duty cycling algorithms lack the capability to meet the dynamic service quality requirements of IoT applications with variable context information. Specifically, they are infeasible for IoT use-cases where multi-hop communication is required. This paper strives to realize efficient resource allocation to the Wi-Fi based IoT devices in multi-hop IoT infrastructures. Firstly, IoT applications are characterized as per their heterogeneous traffic demand and mapped to the distinct weighted quality classes. Then, context awareness is introduced for IoT devices and an optimization model constrained by their service quality requirements and context priorities is presented. Further, an energy efficient context aware traffic scheduling (EE-CATS) algorithm is proposed wherein the convergence of model is specified by a sub-gradient projection method. The EE-CATS algorithm efficiently allocates resources to multi-hop IoT devices and reduce their total awake time by employing adaptive duty cycling. The performance evaluation is done for various IoT use-cases through simulations in Network Simulator (ns-2) and testbed implementation in Contiki operating system. The results suggest substantial improvements in the energy efficiency of IoT devices while ensuring their dynamic service requirements. In addition, the proposed algorithm minimizes the end-to-end delays in overall IoT networks.

      PubDate: 2017-05-08T10:04:30Z
      DOI: 10.1016/j.adhoc.2017.05.001
  • Temperature Compensated Kalman Distributed Clock Synchronization
    • Authors: Fengyuan Gong; Mihail L. Sichitiu
      Abstract: Publication date: Available online 27 April 2017
      Source:Ad Hoc Networks
      Author(s): Fengyuan Gong, Mihail L. Sichitiu
      Time synchronization is a fundamental problem in any distributed system. In particular, wireless sensor networks (WSNs) require scalable time synchronization for implementing distributed tasks on multiple sensor nodes. We propose a temperature-compensated Kalman based distributed synchronization protocol (TKDS) using a two-way sender-receiver synchronization scheme, to achieve high synchronization accuracy while modelling the clock skew change based on its physical characteristics. By asynchronously combining estimates from neighbours, TKDS achieves better performance than the spanning tree based protocols in a fully-distributed fashion. The synchronization performance is evaluated numerically and compared with that of other well-known synchronization protocols.

      PubDate: 2017-05-02T21:14:46Z
      DOI: 10.1016/j.adhoc.2017.04.009
  • Link Selection Strategies based on Network Analysis to Determine Stable
           and Energy-Efficient Data Gathering Trees for Mobile Sensor Networks
    • Authors: Natarajan Meghanathan
      Abstract: Publication date: Available online 25 April 2017
      Source:Ad Hoc Networks
      Author(s): Natarajan Meghanathan
      We propose three different strategies for selecting links that could be part of stable data gathering (DG) trees for mobile sensor networks (MSNs). The proposed strategies are based on metrics (such as: Neighborhood Overlap, Bipartivity Index and Algebraic Connectivity) used in complex network analysis applied on the egocentric network of an edge: a graph comprising of the end nodes of the edge and their neighbors (as vertices) and links incident on the end nodes of the edge (as edges). We hypothesize that an edge whose egocentric network has a larger neighborhood overlap or a smaller bipartivity index or a larger value for algebraic connectivity should have its end nodes share a significant fraction of their neighbors and be a short distance link that is relatively more stable. Through extensive simulations, we show that each of the above three metrics of complex network analysis could be used to determine DG trees that are significantly more stable and energy-efficient compared to the currently best known strategy of using the predicted link expiration time (LET) to determine stable DG trees for MSNs. Also, unlike the LET approach, the proposed strategies could be applied without knowledge about the location and mobility of the nodes.

      PubDate: 2017-04-25T20:56:08Z
      DOI: 10.1016/j.adhoc.2017.04.007
  • On the Rate of Successful Transmissions in Finite Slotted Aloha MANETs
    • Authors: Yin Chen; Jinxiao Zhu; Yulong Shen; Xiaohong Jiang; Hideyuki Tokuda
      Abstract: Publication date: Available online 17 April 2017
      Source:Ad Hoc Networks
      Author(s): Yin Chen, Jinxiao Zhu, Yulong Shen, Xiaohong Jiang, Hideyuki Tokuda
      Mobile ad hoc networks (MANETs) with Aloha MAC protocol (A-MANETs) represent a class of important and attractive networks. This paper studies the Rate of Successful Transmissions (RST), a performance index that measures the average amount of successful transmissions, in a practical A-MANET with finite number of nodes and a class of “uniform-type” mobility models. We first develop a new theoretical framework for the temporal modeling of the concerned finite A-MANET, and prove that as time evolves the network converges in distribution to a Binomial point process. With the help of the convergence property of the network and stochastic geometry theory, we then provide our analysis on the RST. In particular, we show that although it is highly cumbersome (if not impossible) to derive the exact expression for the RST of the concerned network, it is possible to have very efficient approximations to the RST under the typical nearest neighbor/receiver transmission policy, which are accurate up to an additive asymptotic error vanishing exponentially with the number of network nodes. Finally, we provide extensive simulation/numerical results to illustrate the efficiency of our RST modeling and our theoretical findings.

      PubDate: 2017-04-18T20:27:05Z
      DOI: 10.1016/j.adhoc.2017.04.005
  • Maximizing the Wireless Sensor Networks Lifetime through Energy Efficient
           Connected Coverage
    • Authors: J. Roselin; P. Latha; S. Benitta
      Abstract: Publication date: Available online 5 April 2017
      Source:Ad Hoc Networks
      Author(s): J. Roselin, P. Latha, S. Benitta
      Wireless Sensor Network (WSN) is an emerging technology that is gaining much importance owing to its immense contribution in various day-to-day applications. A sensor is battery-operated, unattended low-cost device with limited computing, communication and storage capabilities. Thus the network lifetime has become the key characteristic for evaluating sensor networks in an application-specific way. There are certain approaches in literature which consider the lifetime maximization problem. However, they suffer from impulsive energy hole, coverage hole and communication hole. In this paper we propose a novel Energy Efficient Connected Coverage (EECC) scheduling to maximize the lifetime of the WSN. The EECC adheres to Quality of Service (QoS) metrics such as remaining energy, coverage and connectivity. In EECC the sensor which doesn't contribute to coverage will act as a relay node to reduce the burden of the sensing node. The sensing node senses the target whereas the relaying node communicates the sensory information to the sink. The EECC forms non-disjoint cover sets using remaining energy, coverage and connectivity of every sensor. The proposed EECC outperforms similar scheduling algorithms found in the literature in an energy efficient way with the short execution time. Through simulations the constancy of EECC in extending the lifetime of WSN is confirmed.

      PubDate: 2017-04-12T01:46:59Z
      DOI: 10.1016/j.adhoc.2017.04.001
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