In this thesis we have covered three themes related to wireless sensor networks. The first one concerns the detection of measurement errors in sensor readings in a wireless sensor network. In order to identify a faulty node we have used soft computing techniques. A fuzzy inference system and a recurrent fuzzy inference system are used to model a node as far as its sensor measurement is concerne...

It is necessary for some of the applications of wireless sensor networks (WSNs) to estimate the geographical position of nodes. For the localization of wireless sensor nodes in wireless sensor networks, we took advantage of the learning machine approach based on binary support vector machine (SVM). During offline learning process, the received signal strength from reference nodes was chosen as ...

This paper proposes a hybrid medium access protocol named orthogonal coded medium access control (OrMAC), which extends the principle of distributed queuing collision avoidance protocol (DQCA) of wireless local area network (WLAN) to delay-sensitive machine-to-machine (M2M) networks. OrMAC pre-assigns orthogonal codes, which serve as the channel contention signals, to the nodes entering the net...

In this paper, we consider distributed signal estimation in sensor networks where the nodes exchange compressed sensor signal observations to estimate different node-specific signals. In particular, we revisit the so-called distributed adaptive node-specific signal estimation (DANSE) algorithm, which applies to the case where the nodes share a so-called ‘common interest’, and cast it in the mor...

Directional antennas shape transmission patterns to provide greater coverage distance and reduced coverage angle. Use of adaptive directional antenna arrays can minimize interference while also being more energy efficient. When used in an ad-hoc network, this reduces interference among transmitting nodes and thereby increases throughput. Such “smart antennas” use digital beamforming based on si...

When multiple radio nodes, situated in an arena, simultaneously transmit some messages, whether a node receives a message or not is determined by a mathematical formula involving the signal strengths of the transmitting nodes and their respective physical coordinates and sometimes even the topology in which they are located. Considerable literature has been developed for various fundamental dis...

We consider a network of nodes distributed in physical space without physical links communicating through message broadcasting over specified distances. Typically, communication using smaller distances is desirable due to savings in energy or other resources. We introduce a network formation mechanism to enable reducing the distances while retaining connectivity. Nodes, which initially transmit...

due to limitations in computing resources of mobile nodes, mobile ad-hoc networks (manets) are very fault-prone. so far, redundancy at different levels of the network has been considered an efficient strategy to enhance the fault-tolerance of networks. indeed, ad-hoc networks are extremely redundant; therefore, natural redundancy to fault tolerance enhancement has a great impact on the network ...

Boolean networks have been widely used as models for gene regulatory networks, signal transduction networks, or neural networks, among many others. One of the main difficulties in analyzing the dynamics of a Boolean network and its sensitivity to perturbations or mutations is the fact that it grows exponentially with the number of nodes. Therefore, various approaches for simplifying the computa...

In recent years, wireless sensor networks have drawn great attention. This type of network is composed of a large number of sensor nodes which are able to sense, process and communicate. Besides, they are used in various fields such as emergency relief in disasters, monitoring the environment, military affairs and etc. Sensor nodes collect environmental data by using their sensors and send them...