Consider a fully-connected synchronous distributed system consisting of n nodes, where up to f nodes may be faulty and every node starts in an arbitrary initial state. In the synchronous counting problem, all nodes need to eventually agree on a counter that is increased by one modulo some C in each round. In the self-stabilising firing squad problem, the task is to eventually guarantee that all...

In this paper, we investigate opportunistic relay and jammer cooperation schemes in multiple-input multiple-output (MIMO) buffer-aided relay networks. The network consists of one source, an arbitrary number of relay nodes, legitimate users and eavesdroppers, with the constraints of physical layer security. We propose an algorithm to select a set of relay nodes to enhance the legitimate users’ t...

Measuring the locations of people in a building is an important part of ubiquitous computing. We present new hardware and software for this purpose. The hardware, called SmartMoveX, is an active badge system in which a small radio transmitter is attached to the person being tracked. Receivers placed in the building’s existing offices, connected to existing PCs, transmit signal strength readings...

This paper considers decentralized spectrum sensing, i.e., detection of occupancy of the primary users’ spectrum by a set of Cognitive Radio (CR) nodes, under a Bayesian set-up. The nodes use energy detection to make their individual decisions, which are combined at a Fusion Center (FC) using the K -out-of-N fusion rule. The channel from the primary transmitter to the CR nodes is assumed to und...

We investigate the feasibility of using correlation-based methods for estimating the spatial location of distributed receiving nodes in an indoor environment. Our algorithms do not assume any knowledge regarding the transmitter locations or the transmitted signal, but do assume that there are ambient signal sources whose location and properties are, however, not known. The key idea is to comput...

In this paper, we present results of a study of the data rate fairness among nodes within a LoRaWAN cell. Since LoRa/LoRaWAN supports various data rates, we firstly derive the fairest ratios of deploying each data rate within a cell for a fair collision probability. LoRa/LoRaWAN, like other frequency modulation based radio interfaces, exhibits the capture effect in which only the stronger signa...

Simultaneous wireless information and power transfer (SWIPT) is a promising new solution to provide a perpetual lifetime for energy constrained nodes in wireless networks. In this paper, we consider a wireless sensor relay network, where relay nodes forward a radio frequency (RF) signal from a source node to a destination node by first harvesting energy from the RF signal. For multiple relay no...

In this paper we propose an efficient approach to determine the optimal hops for multi-hop ad hoc wireless networks. Based on the assumption that nodes use successive interference cancellation (SIC) and maximal ratio combining (MRC) to deal with mutual interference and to utilize all the received signal energy, we show that the signal-tointerference-plus-noise ratio (SINR) of a node is determin...

In allusion to the special environment of coal mine roadways, the strategy laying anchor nodes evenly on the left and right sides and the top of roadways in accordance with the oblique triangle and the mine personnel positioning algorithm based on received and transmitted signal strength of nodes were adopted in the paper. The algorithm estimating the distance between an unknown node and an anc...

Abstract To address the issues of the coexistence of the noisy signal channels, the vulnerability of sensor nodes and the limited coverage redundancy of monitoring, which is very common in actual application scenarios, a new decision fusion approach for distributed detection in wireless sensor networks is developed in this paper. A reputation weight is given to every sensor node by the fusion c...