29 research outputs found
Improving energy efficiency in a wireless sensor network by combining cooperative MIMO with data aggregation
In wireless sensor networks where nodes are powered by batteries, it is critical to prolong the network lifetime by minimizing the energy consumption of each node. In this paper, the cooperative multiple-input-multiple-output (MIMO) and data-aggregation techniques are jointly adopted to reduce the energy consumption per bit in wireless sensor networks by reducing the amount of data for transmission and better using network resources through cooperative communication. For this purpose, we derive a new energy model that considers the correlation between data generated by nodes and the distance between them for a cluster-based sensor network by employing the combined techniques. Using this model, the effect of the cluster size on the average energy consumption per node can be analyzed. It is shown that the energy efficiency of the network can significantly be enhanced in cooperative MIMO systems with data aggregation, compared with either cooperative MIMO systems without data aggregation or data-aggregation systems without cooperative MIMO, if sensor nodes are properly clusterized. Both centralized and distributed data-aggregation schemes for the cooperating nodes to exchange and compress their data are also proposed and appraised, which lead to diverse impacts of data correlation on the energy performance of the integrated cooperative MIMO and data-aggregation systems
Energy efficient cooperative coalition selection in cluster-based capillary networks for CMIMO IoT systems
The Cooperative Multiple-input-multiple-output (CMIMO) scheme has been suggested to extend the lifetime of cluster heads (CHs) in cluster-based capillary networks in Internet of Things (IoT) systems. However, the CMIMO scheme introduces extra energy overhead to cooperative devices and further reduces the lifetime of these devices. In this paper, we first articulate the problem of cooperative coalition’s selection for CMIMO scheme to extend the average battery capacity among the whole network, and then propose to apply the quantum-inspired particle swarm optimization (QPSO) to select the optimum cooperative coalitions of each hop in the routing path. Simulation results proved that the proposed QPSO-based cooperative coalition’s selection scheme could select the optimum cooperative sender and receiver devices in every hop dynamically and outperform the virtual MIMO scheme with a fixed number of cooperative devices
Cluster Heads Selection and Cooperative Nodes Selection for Cluster-based Internet of Things Networks
PhDClustering and cooperative transmission are the key enablers in power-constrained Internet
of Things (IoT) networks. The challenges for power-constrained devices in IoT networks
are to reduce the energy consumption and to guarantee the Quality of Service
(QoS) provision. In this thesis, optimal node selection algorithms based on clustering
and cooperative communication are proposed for different network scenarios, in particular:
• The QoS-aware energy efficient cluster heads (CHs) selection algorithm in one-hop
capillary networks. This algorithm selects the optimum set of CHs and construct
clusters accordingly based on the location and residual energy of devices.
• Cooperative nodes selection algorithms for cluster-based capillary networks. By
utilising the spacial diversity of cooperative communication, these algorithms select
the optimum set of cooperative nodes to assist the CHs for the long-haul transmission.
In addition, with the regard of evenly energy distribution in one-hop
cluster-based capillary networks, the CH selection is taken into consideration when
developing cooperative devices selection algorithms.
The performance of proposed selection algorithms are evaluated via comprehensive simulations.
Simulation results show that the proposed algorithms can achieve up to 20%
network lifetime longevity and up to 50% overall packet error rate (PER) decrement.
Furthermore, the simulation results also prove that the optimal tradeoff between energy
efficiency and QoS provision can be achieved in one-hop and multi-hop cluster-based
scenarios.Chinese Scholarship Counci
EARPC – Energy Aware Routing Protocol for Cooperative MIMO Scheme in WSNs, Journal of Telecommunications and Information Technology, 2020, nr 3
Wireless sensor networks are typically operated on batteries. Therefore, in order to prolong network lifetime, an energy efficient routing algorithm is required. In this paper, an energy-aware routing protocol for the co-operative MIMO scheme in WSNs (EARPC) is presented. It is based on an improved cluster head selection method that considers the remaining energy level of a node and recent energy consumption of all nodes. This means that sensor nodes with lower energy levels are less likely to be chosen as cluster heads. Next, based on the cooperative node selection in each cluster, a virtual MIMO array is created, reducing uneven distribution of clusters. Simulation results show that the proposed routing protocol may reduce energy consumption and improve network lifetime compared with the LEACH protoco
Analysis and Ad-hoc Networking Solutions for Cooperative Relaying Systems
Users of mobile networks are increasingly demanding higher data rates from
their service providers. To cater to this demand, various signal processing
and networking algorithms have been proposed. Amongst them the multiple
input multiple output (MIMO) scheme of wireless communications is one of
the most promising options. However, due to certain physical restrictions,
e.g., size, it is not possible for many devices to have multiple antennas
on them. Also, most of the devices currently in use are single-antenna
devices. Such devices can make use of the MIMO scheme by employing
cooperative MIMO methods. This involves nearby nodes utilizing the antennas
of each other to form virtual antenna arrays (VAAs). Nodes with limited
communication ranges can further employ multi-hopping to be able to
communicate with far away nodes. However, an ad-hoc communications scheme
with cooperative MIMO multi-hopping can be challenging to implement because
of its de-centralized nature and lack of a centralized controling entity
such as a base-station. This thesis looks at methods to alleviate the
problems faced by such networks.In the first part of this thesis, we look,
analytically, at the relaying scheme under consideration and derive closed
form expressions for certain performance measures (signal to noise ratio
(SNR), symbol error rate (SER), bit error rate (BER), and capacity) for the
co-located and cooperative multiple antenna schemes in different relaying
configurations (amplify-and-forward and decode-and-forward) and different
antenna configurations (single input single output (SISO), single input
multiple output (SIMO) and MIMO). These expressions show the importance of
reducing the number of hops in multi-hop communications to achieve a better
performance. We can also see the impact of different antenna configurations
and different transmit powers on the number of hops through these
simplified expressions.We also look at the impact of synchronization errors
on the cooperative MIMO communications scheme and derive a lower bound of
the SINR and an expression for the BER in the high SNR regime. These
expressions can help the network designers to ensure that the quality of
service (QoS) is satisfied even in the worst-case scenarios. In the second
part of the thesis we present some algorithms developed by us to help the
set-up and functioning of cluster-based ad-hoc networks that employ
cooperative relaying. We present a clustering algorithm that takes into
account the battery status of nodes in order to ensure a longer network
life-time. We also present a routing mechanism that is tailored for use in
cooperative MIMO multi-hop relaying. The benefits of both schemes are shown
through simulations.A method to handle data in ad-hoc networks using
distributed hash tables (DHTs) is also presented. Moreover, we also present
a physical layer security mechanism for multi-hop relaying. We also analyze
the physical layer security mechanism for the cooperative MIMO scheme. This
analysis shows that the cooperative MIMO scheme is more beneficial than
co-located MIMO in terms of the information theoretic limits of the
physical layer security.Nutzer mobiler Netzwerke fordern zunehmend höhere Datenraten von ihren
Dienstleistern. Um diesem Bedarf gerecht zu werden, wurden verschiedene
Signalverarbeitungsalgorithmen entwickelt. Dabei ist das "Multiple input
multiple output" (MIMO)-Verfahren für die drahtlose Kommunikation eine der
vielversprechendsten Techniken. Jedoch ist aufgrund bestimmter
physikalischer Beschränkungen, wie zum Beispiel die Baugröße, die
Verwendung von mehreren Antennen für viele Endgeräte nicht möglich. Dennoch
können solche Ein-Antennen-Geräte durch den Einsatz kooperativer
MIMO-Verfahren von den Vorteilen des MIMO-Prinzips profitieren.
Dabei schließen sich naheliegende Knoten zusammen um ein sogenanntes
virtuelles Antennen-Array zu bilden. Weiterhin können Knoten mit
beschränktem Kommunikationsbereich durch mehrere Hops mit weiter
entfernten Knoten kommunizieren. Allerdings stellt der Aufbau eines solchen
Ad-hoc-Netzwerks mit kooperativen MIMO-Fähigkeiten aufgrund der dezentralen
Natur und das Fehlen einer zentral-steuernden Einheit, wie einer
Basisstation, eine große Herausforderung dar. Diese Arbeit befasst sich mit
den Problemstellungen dieser Netzwerke und bietet verschiedene
Lösungsansätze.Im ersten Teil dieser Arbeit werden analytisch in
sich geschlossene Ausdrücke für ein kooperatives
Relaying-System bezüglicher verschiedener Metriken, wie das
Signal-Rausch-Verhältnis, die Symbolfehlerrate, die Bitfehlerrate und die
Kapazität, hergeleitet. Dabei werden die "Amplify-and forward" und
"Decode-and-forward" Relaying-Protokolle, sowie unterschiedliche
Mehrantennen-Konfigurationen, wie "Single input single output" (SISO),
"Single input multiple output" (SIMO) und MIMO betrachtet. Diese Ausdrücke
zeigen die Bedeutung der Reduzierung der Hop-Anzahl in Mehr-Hop-Systemen,
um eine höhere Leistung zu erzielen. Zudem werden die Auswirkungen
verschiedener Antennen-Konfigurationen und Sendeleistungen auf die Anzahl
der Hops analysiert. Weiterhin wird der Einfluss von
Synchronisationsfehlern auf das kooperative MIMO-Verfahren herausgestellt
und daraus eine untere Grenze für das
Signal-zu-Interferenz-und-Rausch-Verhältnis, sowie ein Ausdruck für die
Bitfehlerrate bei hohem Signal-Rausch-Verhältnis entwickelt.
Diese Zusammenhänge sollen Netzwerk-Designern helfen die Qualität des
Services auch in den Worst-Case-Szenarien sicherzustellen.
Im zweiten Teil der Arbeit werden einige innovative
Algorithmen vorgestellt, die die Einrichtung und die Funktionsweise von
Cluster-basierten Ad-hoc-Netzwerken, die kooperative Relays verwenden,
erleichtern und verbessern. Darunter befinden sich ein
Clustering-Algorithmus, der den Batteriestatus der Knoten berücksichtigt,
um eine längere Lebensdauer des Netzwerks zu gewährleisten und ein
Routing-Mechanismus, der auf den Einsatz in kooperativen MIMO
Mehr-Hop-Systemen zugeschnitten ist. Die Vorteile beider Algorithmen werden
durch Simulationen veranschaulicht.
Eine Methode, die Daten in Ad-hoc-Netzwerken mit verteilten Hash-Tabellen
behandelt wird ebenfalls vorgestellt. Darüber hinaus wird auch
ein Sicherheitsmechanismus für die physikalische Schicht in
Multi-Hop-Systemen und kooperativen MIMO-Systemen präsentiert. Eine Analyse
zeigt, dass das kooperative MIMO-Verfahren deutliche Vorteile gegenüber dem
konventionellen MIMO-Verfahren hinsichtlich der informationstheoretischen
Grenzen der Sicherheit auf der physikalischen Schicht aufweist
Real-Time QoS Routing Protocols in Wireless Multimedia Sensor Networks: Study and Analysis
Many routing protocols have been proposed for wireless sensor networks. These routing protocols are almost always based on energy efficiency. However, recent advances in complementary metal-oxide semiconductor (CMOS) cameras and small microphones have led to the development of Wireless Multimedia Sensor Networks (WMSN) as a class of wireless sensor networks which pose additional challenges. The transmission of imaging and video data needs routing protocols with both energy efficiency and Quality of Service (QoS) characteristics in order to guarantee the efficient use of the sensor nodes and effective access to the collected data. Also, with integration of real time applications in Wireless Senor Networks (WSNs), the use of QoS routing protocols is not only becoming a significant topic, but is also gaining the attention of researchers. In designing an efficient QoS routing protocol, the reliability and guarantee of end-to-end delay are critical events while conserving energy. Thus, considerable research has been focused on designing energy efficient and robust QoS routing protocols. In this paper, we present a state of the art research work based on real-time QoS routing protocols for WMSNs that have already been proposed. This paper categorizes the real-time QoS routing protocols into probabilistic and deterministic protocols. In addition, both categories are classified into soft and hard real time protocols by highlighting the QoS issues including the limitations and features of each protocol. Furthermore, we have compared the performance of mobility-aware query based real-time QoS routing protocols from each category using Network Simulator-2 (NS2). This paper also focuses on the design challenges and future research directions as well as highlights the characteristics of each QoS routing protocol.https://doi.org/10.3390/s15092220
An Efficient Data Collection Protocol Based on Multihop Routing and Single-Node Cooperation in Wireless Sensor Networks
Considering the constrained resource and energy in wireless sensor networks, an efficient data collection protocol named ESCDD which adopts the multihop routing technology and the single-node selection cooperative communication is proposed to make the communication protocol more simple and easy to realize for the large-scale multihop wireless sensor networks. ESCDD uses the greedy strategy and the control information based on RTS/CTS to select forwarding nodes. Then, the hops in the multihop data transmission are reduced. Based on the power control in physical layer and the control frame called CoTS in MAC layer, ESCDD chooses a single cooperative node to perform cooperative transmission. The receiving node adopts maximal ratio combining (MRC) to recover original data. The energy consumption per hop is reduced. Furthermore, the total energy consumption in data collection process is shared by more nodes and the network lifetime is extended. Compared with GeRaF, EERNFS, and REEFG protocol, the simulation results show that ESCDD can effectively reduce the average delay of multihop data transmission, improve the successful delivery rate of data packets, significantly save the energy consumption of network nodes, and make the energy consumption more balanced
Thirty Years of Machine Learning: The Road to Pareto-Optimal Wireless Networks
Future wireless networks have a substantial potential in terms of supporting
a broad range of complex compelling applications both in military and civilian
fields, where the users are able to enjoy high-rate, low-latency, low-cost and
reliable information services. Achieving this ambitious goal requires new radio
techniques for adaptive learning and intelligent decision making because of the
complex heterogeneous nature of the network structures and wireless services.
Machine learning (ML) algorithms have great success in supporting big data
analytics, efficient parameter estimation and interactive decision making.
Hence, in this article, we review the thirty-year history of ML by elaborating
on supervised learning, unsupervised learning, reinforcement learning and deep
learning. Furthermore, we investigate their employment in the compelling
applications of wireless networks, including heterogeneous networks (HetNets),
cognitive radios (CR), Internet of things (IoT), machine to machine networks
(M2M), and so on. This article aims for assisting the readers in clarifying the
motivation and methodology of the various ML algorithms, so as to invoke them
for hitherto unexplored services as well as scenarios of future wireless
networks.Comment: 46 pages, 22 fig
Power-efficient Location-based Cooperative Routing with Sensor Power Upper Limit for Wireless Sensor Networks
A location-based cooperative routing algorithm is proposed to improve the wireless sensor network performance.[ANGLÈS] Cooperative routing in wireless sensor networks can improve performance in these types of networks. In our work, we propose a routing algorithm called Location-based Cooperative Routing with Sensor Power-upper-limit for Wireless Sensor Networks. The algorithm is based on the principle of minimum link power and aims to take advantage of nodes cooperation to make the link work well in Wireless Sensor Networks with a low transmission power. In the proposed scheme, with a determined sending power upper limit, nodes find the most appropriate next nodes and single-relay nodes with the proposed algorithm. Moreover, this proposal subtly avoids the nodes not working, because we add Bad nodes Avoidance Strategy. Simulation results show that, compared with other routing algorithm, the algorithm proposed in previous study, proposed algorithm with Bad nodes Avoidance Strategy can significantly improve the performance in reducing the overall link power, enhancing the transmission success rate and decreasing the retransmission rate.[CASTELLÀ] Cooperative routing en redes de sensores inalámbricos puede mejorar el rendimiento en este tipo de redes. En nuestro trabajo, proponemos un algoritmo de enrutamiento llamado Location-based Cooperative Routing with Sensor Power-upper-limit for Wireless Sensor Networks. El algoritmo se basa en el principio de la potencia de enlace mínimo, y tiene como objetivo aprovechar la cooperación de los nodos para hacer que el enlace funcione bien en redes de sensores inalámbricos con una potencia de transmisión baja. En el esquema propuesto, con un límite de envío de potencia determinado, los nodos pueden encontrar los nodos siguientes más apropiados y los nodos relay con el algoritmo propuesto. Por otra parte, esta propuesta sutilmente evita los nodos que no funcionan, porque añade la estrategia Bad nodes Avoidance Strategy (BAS). Los resultados de simulación muestran que, en comparación con otro algoritmo de enrutamiento, el algoritmo propuesto con la estrategia de BAS puede mejorar significativamente el rendimiento en la reducción de la potencia del enlace general, aumentar la tasa de éxito de transmisión y la disminución de la tasa de retransmisión.[CATALÀ] Cooperative routing en xarxes de sensors sense fil pot millorar el rendiment en aquest tipus de xarxes. En el nostre treball, proposem un algorisme d'encaminament anomenat Location-based Cooperative Routing with Sensor Power-upper-limit for Wireless Sensor Networks. L'algorisme es basa en el principi de la potència d'enllaç mínim i té com objectiu aprofitar la cooperació dels nodes per fer que l'enllaç funcioni bé en xarxes de sensors sense fil amb una potència de transmissió baixa. En l'esquema proposat, sense límit d'enviament de potència determinat, els nodes poden trobar els relays més apropiats amb l'algorisme proposat. Per altra part, aquesta proposta evita els nodes que no funcionen bé, perquè s'afegeix l'estratègia Bad nodes Avoidance Strategy (BAS). Els resultats de simulació mostren que, en comparació amb un altre algorisme d'encaminament, l'algorisme proposat amb l'estratègia de BAS pot millorar significativament el rendiment en la reducció de la potència de l'enllaç general, augmentar la taxa d'èxit de transmissió i la disminució de la taxa de retransmissió