Browsing by Subject "Network lifetime"

Now showing 1 - 11 of 11

Open Access
An adaptive, energy-aware and distributed fault-tolerant topology-control algorithm for heterogeneous wireless sensor networks
(Elsevier BV, 2016) Deniz, F.; Bagci, H.; Korpeoglu, I.; Yazıcı A.
This paper introduces an adaptive, energy-aware and distributed fault-tolerant topology-control algorithm, namely the Adaptive Disjoint Path Vector (ADPV) algorithm, for heterogeneous wireless sensor networks. In this heterogeneous model, we have resource-rich supernodes as well as ordinary sensor nodes that are supposed to be connected to the supernodes. Unlike the static alternative Disjoint Path Vector (DPV) algorithm, the focus of ADPV is to secure supernode connectivity in the presence of node failures, and ADPV achieves this goal by dynamically adjusting the sensor nodes' transmission powers. The ADPV algorithm involves two phases: a single initialization phase, which occurs at the beginning, and restoration phases, which are invoked each time the network's supernode connectivity is broken. Restoration phases utilize alternative routes that are computed at the initialization phase by the help of a novel optimization based on the well-known set-packing problem. Through extensive simulations, we demonstrate that ADPV is superior in preserving supernode connectivity. In particular, ADPV achieves this goal up to a failure of 95% of the sensor nodes; while the performance of DPV is limited to 5%. In turn, by our adaptive algorithm, we obtain a two-fold increase in supernode-connected lifetimes compared to DPV algorithm.
Open Access
Algorithms for sink mobility in wireless sensor networks to improve network lifetime
(Springer, 2012-09) Koç, Metin; Körpeoğlu, İbrahim
Sink mobility is an effective solution in the literature for wireless sensor network lifetime improvement. In this paper, we propose a set of algorithms for sink site determination (SSD) and movement strategy problems of sink mobility. We also present experiment results that compare the performance of our algorithms with other approaches in the literature. © 2012 Springer-Verlag London Limited.
Open Access
Controlled sink mobility algorithms for wireless sensor networks
(Taylor and Francis Inc., 2014) Koç, M.; Korpeoglu I.
A wireless sensor network (WSN) consists of hundreds or thousands of sensor nodes organized in an ad hoc manner to achieve a predefined goal. Although WSNs have limitations in terms of memory and processors, the main constraint that makes WSNs different from traditional networks is the battery problem which limits the lifetime of a network. Different approaches are proposed in the literature for improving the network lifetime, including data aggregation, energy efficient routing schemes, and MAC protocols. Sink node mobility is also an effective approach for improving the network lifetime. In this paper, we investigate controlled sink node mobility and present a set of algorithms for deciding where and when to move a sink node to improve network lifetime. Moreover, we give a load-balanced topology construction algorithm as another component of our solution. We did extensive simulation experiments to evaluate the performance of the components of our mobility scheme and to compare our solution with static case and random movement strategy. The results show that our algorithms are effective in improving network lifetime and provide significantly better lifetime compared to static sink case and random movement strategy. © 2014 Metin Koç and Ibrahim Korpeoglu.
Open Access
Coordinated movement of multiple mobile sinks in a wireless sensor network for improved lifetime
(SpringerOpen, 2015) Koç, M.; Korpeoglu, I.
Sink mobility is one of the most effective solutions for improving lifetime and has been widely investigated for the last decade. Algorithms for single-sink mobility are not directly applied to the multiple-sink case due to the latter’s specific challenges. Most of the approaches proposed in the literature use mathematical programming techniques to solve the multiple-sink mobility problem. However, doing so leads to higher complexities when traffic flow information for any possible sink-site combinations is included in the model. In this paper, we propose two algorithms that do not consider all possible sink-site combinations to determine migration points. We first present a centralized movement algorithm that uses an energy-cost matrix for a user-defined threshold number of combinations to coordinate multiple-sink movement. We also give a distributed algorithm that does not use any prior network information and has a low message exchange overhead. Our simulations show that the centralized algorithm gives better network lifetime performance compared to previously proposed MinDiff-RE, random movement, and static-sink algorithms. Our distributed algorithm has a lower network lifetime than centralized algorithms; sinks travel significantly less than in all the other schemes.
Open Access
Distributed power-source-aware routing in wireless sensor networks
(Springer New York LLC, 2016) Tekkalmaz, M.; Korpeoglu, I.
Although many applications use battery-powered sensor nodes, in some applications battery- and mains-powered nodes coexist. In this paper, we present a distributed algorithm that considers using mains-powered devices to increase the lifetime of wireless sensor networks for such heterogeneous deployment scenarios. In the proposed algorithm, a backbone routing structure composed of mains-powered nodes, sink, and battery-powered nodes if required, is constructed to relay data packets to one or more sinks. The algorithm is fully distributed and can handle dynamic changes in the network, such as node additions and removals, as well as link failures. Our extensive ns-2 simulation results show that the proposed method is able to increase the network lifetime up to 40 % compared to the case in which battery- and mains-powered nodes are not differentiated. © 2015, Springer Science+Business Media New York.
Open Access
EHPBS: Energy harvesting prediction based scheduling in wireless sensor networks
(IEEE, 2013) Akgun, B.; Aykın, Irmak
The clustering algorithms designed for traditional sensor networks have been adapted for energy harvesting sensor networks (EHWSN). However, in these algorithms, the intra-cluster MAC protocols to be used were either not defined at all or they were TDMA based. These TDMA based MAC protocols are not specified except for the fact that cluster heads assign time slots to their members in a random manner. In this paper, we will modify this TDMA based scheduling as follows: members will request a time slot depending on their energy prediction and the cluster heads will assign these slots to members. This method will increase the network lifetime. The proof will be given with simulations. © 2013 IEEE.
Open Access
Energy efficient routing
(Springer, Berlin, Heidelberg, 2007) Körpeoğlu, İbrahim; Mahalik, N. P.
Open Access
Energy load balancing for fixed clustering in wireless sensor networks
(IEEE, 2012) Ali, Syed Amjad; Sevgi, C.
Clustering can be used as an effective technique to achieve both energy load balancing and an extended lifetime for a wireless sensor network (WSN). This paper presents a novel approach that first creates energy balanced fixed/static clusters, and then, to attain energy load balancing within each fixed cluster, rotates the role of cluster head through uniformly quantized energy levels based approach to prolong the overall network lifetime. The method provided herein, not only provides near-dynamic clustering performance but also reduces the complexity due to the fact that cluster formation phase is implemented once. The presented simulation results clearly show the efficacy of this proposed algorithm and thus, it can be used as a practical approach to obtain maximized network lifetime for energy balanced clusters in fixed clustering environments. © 2012 IEEE.
Open Access
Power-source-aware backbone routing in wireless sensor networks
(IEEE, 2010-11) Tekkalmaz, Metin; Körpeoğlu, İbrahim
Due to the limited energy-source and mostly unattended nature of the wireless sensor networks, efficient use of energy has a critical importance on the lifetime of the applications accomplished by such networks. Although in most of the cases sensor nodes are battery-powered, there are application scenarios in which battery- and mains-powered nodes coexist. In this paper, we present an approach and algorithms based on this approach that increase the lifetime of wireless sensor networks in such heterogeneous deployment cases. In the proposed approach, a backbone, which is composed of mains-powered nodes, sink, and battery-powered nodes if required, is constructed to relay the data packets. Simulation results show that, the proposed approach is able to increase the network lifetime up to more than a factor of two, compared to the case in which battery- and mains-powered nodes are not distinguished.
Open Access
PSAR: Power-source-aware routing in ZigBee networks
(2012) Tekkalmaz, M.; Korpeoglu I.
ZigBee is a recent wireless networking technology built on IEEE 802.15.4 standard and designed especially for low-data rate and low-duty cycle applications such as home and building automation and sensor networks. One of the primary goals of ZigBee is low power consumption and therefore long-living networks. Despite this goal, current network formation and routing protocols described in the ZigBee specification do not fully address power consumption issues. In this work, we propose a distributed routing algorithm to reduce power consumption of battery-powered devices by routing the communication through mains-powered devices whenever possible and consequently increasing the overall network lifetime. The proposed algorithm works on tree topologies supported by ZigBee and requires only minor modifications to the current specification. Our ns-2 simulation results showed that the algorithm is able to reduce the power consumption of battery-powered devices significantly with minimal communication overhead. © Springer Science+Business Media, LLC 2012.
Open Access
Resilient multi-hop autonomous UAV networks with extended lifetime for multi-target surveillance
(IEEE, 2025-01-13) Dağaşan, Abdulsamet; Karaşan, Ezhan
Cooperative utilization of Unmanned Aerial Vehicles (UAVs) in public and military surveillance applications has attracted significant attention in recent years. Most UAVs are equipped with sensors and wireless communication equipment with limited ranges. Such limitations pose challenging problems to monitor mobile targets. This paper examines fulfilling surveillance objectives to achieve better coverage while building a resilient network between UAVs with an extended lifetime. The multiple target tracking problem is studied by including a relay UAV within the fleet whose trajectory is autonomously calculated in order to achieve a reliable connected network among all UAVs. Optimization problems are formulated for single-hop and multi-hop communications among UAVs. Three heuristic algorithms are proposed for multi-hop communications and their performances are evaluated. A hybrid algorithm, which dynamically switches between single-hop and multi-hop communications is also proposed. The effect of the time horizon considered in the optimization problem is also studied. Performance evaluation results show that the trajectories generated for the relay UAV by the hybrid algorithm can achieve network lifetimes that are within 95% of the maximum possible network lifetime which can be obtained if the entire trajectories of all targets were known a priori.