143 research outputs found
An energy-aware and QOS assured wireless multi-hop transmission protocol
A thesis submitted in fulfillment of the requirements for the degree of Master of Science by researchThe Ad-hoc network is set up with multiple wireless devices without any pre-existing infrastructure. It usually supports best-effort traffic and occasionally some kinds of Quality of Service (QoS). However, there are some applications with real-time traffic requirements where deadlines must be met. To meet deadlines, the communication network has to support the timely delivery of inter-task messages. Furthermore, energy efficiency is a critical issue for battery-powered mobile devices in ad-hoc networks. Thus, A QoS guaranteed and energy-aware transmission scheme is one hot of research topics in the research area.
The MSc research work is based on the idea of Real-Time Wireless Multi-hop Protocol (RT-WMP). RT-WMP is a well known protocol originally used in the robots control area. It allows wireless real-time traffic in relatively small mobile ad-hoc networks using the low-cost commercial IEEE 802.11 technology. The proposed scheme is based on a token-passing approach and message exchange is priority based.
The idea of energy-aware routing mechanism is based on the AODV protocol. This energy-saving mechanism is analysed and simulated in our study as an extension of the RT-WMP.
From the simulation results and analysis, it has been shown that adding energy-aware mechanism to RT-WMP is meaningful to optimise the performance of traffic on the network
Energy Efficient Routing Algorithms for Wireless Sensor Networks and Performance Evaluation of Quality of Service for IEEE 802.15.4 Networks
The popularity of Wireless Sensor Networks (WSN) have increased tremendously in recent time due to growth in Micro-Electro-Mechanical Systems (MEMS) technology. WSN has the potentiality to connect the physical world with the virtual world by forming a network of sensor nodes. Here, sensor nodes are usually battery-operated devices, and hence energy saving of sensor nodes is a major design issue. To prolong the network‘s lifetime, minimization of energy consumption should be implemented at all layers of the network protocol stack starting from the physical to the application layer including cross-layer optimization.
In this thesis, clustering based routing protocols for WSNs have been discussed. In cluster-based routing, special nodes called cluster heads form a wireless backbone to the sink. Each cluster heads collects data from the sensors belonging to its cluster and forwards it to the sink. In heterogeneous networks, cluster heads have powerful energy devices in contrast to homogeneous networks where all nodes have uniform and limited resource energy. So, it is essential to avoid quick depletion of cluster heads. Hence, the cluster head role rotates, i.e., each node works as a cluster head for a limited period of time. Energy saving in these approaches can be obtained by cluster formation, cluster-head election, data aggregation at the cluster-head nodes to reduce data redundancy and thus save energy. The first part of this thesis discusses methods for clustering to improve energy efficiency of homogeneous WSN. It also proposes Bacterial Foraging Optimization (BFO) as an algorithm for cluster head selection for WSN. The simulation results show improved performance of BFO based optimization in terms of total energy dissipation and no of alive nodes of the network system
over LEACH, K-Means and direct methods.
IEEE 802.15.4 is the emerging next generation standard designed for low-rate wireless personal area networks (LR-WPAN). The second part of the work reported here in provides performance evaluation of quality of service parameters for WSN based on IEEE 802.15.4 star and mesh topology. The performance studies have been evaluated for varying traffic loads using MANET routing protocol in QualNet 4.5. The data packet delivery ratio, average end-to-end delay, total energy consumption, network lifetime and percentage of time in sleep mode have been used as performance metrics. Simulation results show that DSR (Dynamic Source Routing) performs better than DYMO (Dynamic MANET On-demand) and AODV (Ad–hoc On demand Distance Vector) routing protocol for varying traffic loads rates
Performance and energy efficiency in wireless self-organized networks
fi=vertaisarvioitu|en=peerReviewed
Variable power transmission in highly Mobile Ad-Hoc Networks
Mobile Ad Hoc Networks pose challenges in terms of power control, due to their fixed
transmission power, the mobility of nodes and a constantly changing topology. High
levels of power are needed in wireless networks, particularly for routing. As a result of
the increase in the number of communication devices being used, there is the challenge
of increased density within these networks, and a need to extend the battery life of communication
devices.
In order to address this challenge, this thesis presents the development of a new protocol
(Dynamic Power AODV), which is an enhancement of the Ad Hoc On Demand Distance
Vector (AODV) protocol. The new protocol dynamically adjusts the transmission power
based on the range, which depends on node density.
This thesis provides a systematic evaluation of the performance of DP-AODV, in a high
speed and high density environment, in comparison with three other routing protocols.
The experiments demonstrated that DP-AODV performed better than two of the protocols
in all scenarios. As compared to the third protocol (AOMDV), DP-AODV gave
better performance results for throughput and Power Consumption, but AOMDV performed
better in terms of Packet Delivery Fraction rate and End-to-End Delay in some
cases
Constructive Relay based Cooperative Routing in Mobile Ad hoc Networks
PhDMobile Ad hoc networks (MANETs) are flexible networks that transmit packets node-by-node along a route connecting a given source and destination. Frequent link breaks (due to node mobility) and quick exhaustion of energy (due to
limited battery capacity) are two major problems impacting on the
flexibility of MANETs. Cooperative communication is a key concept for improving the system
lifetime and robustness and has attracted considerable attention. As a result, there
is much published research concerning how to utilize cooperative communication
in a MANET context. In the past few years, most cooperative technologies have focused on lower layer enhancements, such as with the Physical Layer and MAC Layer, and have become very mature. At the Network Layer, although some research has been proposed, issues still remain such as the lack of a systematically designed cooperative routing scheme (including route discovery, route reply, route enhancement and cooperative data forwarding), the use of cooperative communication for mobility resilience, and route selection (jointly considering the energy consumption, energy harvesting potential and link break probability).
Driven by the above concerns, a novel Constructive Relay based CooPerative
Routing (CRCPR) protocol based on a cross-layer design is proposed in this thesis.
In CRCPR, we fi rst modify the traditional hello message format to carry some
additional neighbour information. Based on this information, a key aspect of this
protocol is to construct one or more small rhombus topologies within the MANET
structure, which are stored and maintained in a COoPerative (COP) Table and
Relay Table. Next, the route request procedure is re-designed to improve resilience
to node mobility with a scheme called Last hop Replacement. Finally, assuming
nodes are mostly battery-powered, destination node based route-decision criteria
are explored that can consider energy consumption, energy harvesting and link
break probability to determine an appropriate route across the MANET.
As the hello message format is modi ed to carry additional information, the
control overhead is increased. However, in order to improve the control message
eficiency, a new generalised hello message broadcasting scheme entitled Adjust
Classi ed Hello Scheme is developed, which can be deployed onto every routing
protocol employing a hello mechanism.
As well as designing a new routing protocol for MANETs, including route discovery,
route selection, route reply, route maintenance, route enhancement and cooperative
data forwarding, the proposed scheme is implemented within an Opnetbased
simulation environment and evaluated under a variety of realistic conditions.
The results con rm that CRCPR improves mobility resilience, saves energy via
cooperative communication and reduces the control overhead associated with the
hello message mechanism.Chinese Scholarship Counci
Using genetic algorithms to optimise Wireless Sensor Network design
Wireless Sensor Networks(WSNs) have gained a lot of attention because of their potential to immerse deeper into people' lives. The applications of WSNs range from small home environment networks to large habitat monitoring. These highly diverse scenarios impose different requirements on WSNs and lead to distinct design and implementation decisions. This thesis presents an optimization framework for WSN design which selects a proper set of protocols and number of nodes before a practical network
deployment. A Genetic Algorithm(GA)-based Sensor Network Design Tool(SNDT) is proposed in this work for wireless sensor network design in terms of performance, considering application-specific requirements, deployment constrains and energy characteristics. SNDT relies on offine simulation analysis to help resolve design decisions. A GA is used as the optimization tool of the proposed system and an appropriate fitness function is derived to incorporate many aspects of network performance. The configuration attributes optimized by SNDT comprise the communication protocol selection and the number of nodes deployed in a fixed area. Three specific cases : a periodic-measuring application, an event detection type of application and a tracking-based application are considered to demonstrate and assess how the proposed framework performs. Considering the initial requirements of each case, the solutions provided by SNDT were proven to be favourable in terms of energy consumption, end-to-end delay and loss. The user-defined application requirements were successfully achieved
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A survey on Bluetooth multi-hop networks
Bluetooth was firstly announced in 1998. Originally designed as cable replacement connecting devices in a point-to-point fashion its high penetration arouses interest in its ad-hoc networking potential. This ad-hoc networking potential of Bluetooth is advertised for years - but until recently no actual products were available and less than a handful of real Bluetooth multi-hop network deployments were reported. The turnaround was triggered by the release of the Bluetooth Low Energy Mesh Profile which is unquestionable a great achievement but not well suited for all use cases of multi-hop networks. This paper surveys the tremendous work done on Bluetooth multi-hop networks during the last 20 years. All aspects are discussed with demands for a real world Bluetooth multi-hop operation in mind. Relationships and side effects of different topics for a real world implementation are explained. This unique focus distinguishes this survey from existing ones. Furthermore, to the best of the authors’ knowledge this is the first survey consolidating the work on Bluetooth multi-hop networks for classic Bluetooth technology as well as for Bluetooth Low Energy. Another individual characteristic of this survey is a synopsis of real world Bluetooth multi-hop network deployment efforts. In fact, there are only four reports of a successful establishment of a Bluetooth multi-hop network with more than 30 nodes and only one of them was integrated in a real world application - namely a photovoltaic power plant. © 2019 The Author
Swarm intelligence and its applications to wireless ad hoc and sensor networks.
Swarm intelligence, as inspired by natural biological swarms, has numerous powerful
properties for distributed problem solving in complex real world applications such
as optimisation and control. Swarm intelligence properties can be found in natural
systems such as ants, bees and birds, whereby the collective behaviour of unsophisticated
agents interact locally with their environment to explore collective problem solving
without centralised control. Recent advances in wireless communication and digital
electronics have instigated important changes in distributed computing. Pervasive
computing environments have emerged, such as large scale communication networks
and wireless ad hoc and sensor networks that are extremely dynamic and unreliable.
The network management and control must be based on distributed principles where
centralised approaches may not be suitable for exploiting the enormous potential of
these environments. In this thesis, we focus on applying swarm intelligence to the
wireless ad hoc and sensor networks optimisation and control problems.
Firstly, an analysis of the recently proposed particle swarm optimisation, which is
based on the swarm intelligence techniques, is presented. Previous stability analysis
of the particle swarm optimisation was restricted to the assumption that all of the
parameters are non random since the theoretical analysis with the random parameters
is difficult. We analyse the stability of the particle dynamics without these restrictive
assumptions using Lyapunov stability and passive systems concepts. The particle
swarm optimisation is then used to solve the sink node placement problem in sensor
networks.
Secondly, swarm intelligence based routing methods for mobile ad hoc networks
are investigated. Two protocols have been proposed based on the foraging behaviour
of biological ants and implemented in the NS2 network simulator. The first protocol
allows each node in the network to choose the next node for packets to be
forwarded on the basis of mobility influenced routing table. Since mobility is one of
the most important factors for route changes in mobile ad hoc networks, the mobility
of the neighbour node using HELLO packets is predicted and then translated into a
pheromone decay as found in natural biological systems. The second protocol uses
the same mechanism as the first, but instead of mobility the neighbour node remaining
energy level and its drain rate are used. The thesis clearly shows that swarm
intelligence methods have a very useful role to play in the management and control
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problems associated with wireless ad hoc and sensor networks. This thesis has given
a number of example applications and has demonstrated its usefulness in improving
performance over other existing methods
Energy-Efficient Design of Adhoc and Sensor Networks
Adhoc and sensor networks (ASNs) are emerging wireless networks that are expected to have significant impact on the efficiency of many military and civil applications. However, building ASNs efficiently poses a considerable technical challenge because of the many constraints imposed by the environment, or by the ASN nodes capabilities themselves. One of the main challenges is the finite supply energy.Since the network hosts are battery operated, they need to be energy conserving so that the nodes and hence the network itself does not expire. In this thesis different techniques for anenergy-efficient design for ASNs are presented. My work spans two layers of the network protocol stack; these are the Medium Access Layer (MAC) and the Routing Layer. This thesis first identifies and highlights the different sources of energy inefficiency in ASNs, and then it describes how each of these inefficiencies is handled. Toward this goal, I first focus on the Medium Access (MAC) Layer and present my work that handles the wasted energy in transmission and describe how the transmission distance is optimized to extend the network lifetime. I then describe BLAM, an energy-efficient extension for the IEEE 802.11, that handles the wasted energy in collisions. Next, TDMA-ASAP, a new MAC protocol for sensor networks, is introduced. TDMA-ASAP targets the wasted energy in idle listening. I also investigate energy-efficiency at the routing layer level. First, the ``Flooding-Waves' problem is identified. This is a problem in any cost-based energy-efficient routing protocol for adhoc networks, different ways of solving this problem are presented. For sensor networks routing trees are usually used, I introduce a new routing scheme called RideSharing which is energy-efficient and fault-tolerant. RideSharing will deliver a better aggregate result to the end user while masking network linkfailures. Next, I present how to extend the RideSharing scheme to handle different link quality models. Finally, I introduce GroupBeat,a new health detection system for sensor networks, which when combined with RideSharing can deliver the information to the end user even in case of node failures
Robust Ad-hoc Sensor Routing (RASeR) protocol for mobile wireless sensor networks
Robust Ad-hoc Sensor Routing (RASeR) is a novel protocol for data routing in mobile wireless sensor networks (MWSNs). It is designed to cope with the demanding requirements of emerging technologies, which require the reliable and low-latency delivery of packets in highly mobile conditions. RASeR uses blind forwarding, which is facilitated by a novel method of gradient maintenance. The problem of maintaining a gradient field in a changing topology, without flooding, is solved by using a global time division multiple access MAC. Furthermore, it is enhanced with the additional options of a supersede mode, to aid time-critical applications, reverse flooding, to allow sink-to-sensor commands and energy saving sleep cycles to reduce power consumption. Analytical expressions are derived and verified by simulation. RASeR is compared with the state-of-the-art MWSN routing protocols, PHASeR and MACRO, as well as the MANET protocols, AODV and OLSR. The results indicate that RASeR is a high performance protocol, which shows improvements over PHASeR, MACRO, AODV and OLSR. Tested over varying levels of mobility, scalability and traffic, the simulations yield near perfect PDR in many scenarios, as well as a low end-to-end delay, high throughput, low overhead and low energy consumption. The robustness of this protocol and its consistent reliability, low latency and additional features, makes it highly suitable to a wide number of applications. It is specifically applicable to highly mobile situations with a fixed number of nodes and small payloads
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