Nano Communication Networks最新文献

A tunable terahertz circularly-polarized dielectric resonator antenna is implemented and numerically studied. An aperture coupled terahertz rectangular dielectric resonator antenna operating with the fundamental magnetic dipole is designed. The modal field distribution is perturbed using the material-perturbation technique and the electric field vectors are aligned in the horizontal plane with their orthogonal components having quadrature phase difference between them. Consequently, the circular polarization is obtained in the operating passband. The proposed antenna provides the 10-dB impedance bandwidth of 12.94% (4.27–4.86 THz) and 3 dB axial ratio bandwidth of 3.77% (4.43–4.60 THz). Moreover, tunability is achieved by modulation in the chemical potential of graphene layer coated at the top of the dielectric resonator by applying an electrostatic bias voltage. In addition, antenna provides the gain of 6.45 dBic along with 98% radiation efficiency. The proposed antenna can also be used for the implementation of multi-port wireless THz communication systems with the advantage of tunable CP response with impeccably high radiation performance parameters. A two-port multi input, multi output (MIMO) antenna is implemented with the usage of the proposed metal strip coated DR. This antenna provides high isolation between both the ports along with polarization response and pattern diversity with the acceptable value of MIMO performance parameters like envelop correlation coefficient and diversity gain.

Recent advancements in nanotechnology opened the doors for the realization of nanometer-sized integrated devices called nanobots with sensing, actuation, data processing and storage, and communication capabilities. The communication of the nanobots in the sense of intrabody nanonetworks allows possibilities of innovative medical applications for monitoring, drug delivery, and nanosurgery inside the human body. Due to their incredibly small sizes, the nanobots have to operate under extreme computational and energy constraints. Nanobots are self-powered by harvesting energy from their ambient (blood vessels) and their energy is mainly used for the transmission and reception of wireless communication signals. Thus, energy management is very important for the feasibility of the intrabody nanonetworks by directly impacting their performance and reliability. In this paper, we propose a hybrid wired/wireless intrabody ultra-dense nanonetwork architecture where the nearby nanobots form temporarily wired clusters reducing the required total wireless transmission and reception in the network leading to the lower energy use of the communication. We consider the use of coaxial nanocables terminated by nanomagnets to form nano-wired clusters with self-aligned and binding magnetic nanoplugs. Due to the highly dynamic topology of these nano-wired clusters, we propose a very lightweight and adaptable clustering and energy management algorithm to select cluster heads on-the-fly and transmit data wiredly in the cluster and wirelessly between the clusters. We investigate the performance impact of the proposed hybrid solution with the means of extensive simulations in the NS-3 platform and the Nano-sim tool. The results show up to three times more packet delivery on high nanobot densities with the proposed hybrid approach leading to much higher network reliability.

A number of transmission models for airborne pathogens transmission, as required to understand airborne infectious diseases such as COVID-19, have been proposed independently from each other, at different scales, and by researchers from various disciplines. We propose a communication engineering approach that blends different disciplines such as epidemiology, biology, medicine, and fluid dynamics. The aim is to present a unified framework using communication engineering, and to highlight future research directions for modeling the spread of infectious diseases through airborne transmission. We introduce the concept of mobile human ad hoc networks (MoHANETs), which exploits the similarity of airborne transmission-driven human groups with mobile ad hoc networks and uses molecular communication as the enabling paradigm. In the MoHANET architecture, a layered structure is employed where the infectious human emitting pathogen-laden droplets and the exposed human to these droplets are considered as the transmitter and receiver, respectively. Our proof-of-concept results, which we validated using empirical COVID-19 data, clearly demonstrate the ability of our MoHANET architecture to predict the dynamics of infectious diseases by considering the propagation of pathogen-laden droplets, their reception and mobility of humans.

Molecular communication via diffusion (MCvD) schemes are limited to short distances between the nanomachines due to the transmitted signal becoming rapidly weaker as the distance increases. Additionally, these schemes are very often affected by high inter-symbol interference, which makes them prone to errors, thus leading to unreliability. In this paper, a novel system is proposed, which aims to enhance the received signal shape and the overall performance of MCvD schemes over longer distances. A relay nanomachine is introduced between the transmitter–receiver pair, which collects the first portion of the molecules emitted from the transmitter and keeps them for some delay time $\tau$, then releases them towards the receiver, such that the delayed and non-delayed portions of the molecules arrive almost at the same time. In this way, the signal’s strength is enhanced by pointing more molecules towards the intended direction, that is, the receiver node. An analytical model for the optimal relaying scheme is proposed, alongside with an optimization problem to find the most advantageous $\tau$ value. Comparison between the proposed scheme and the conventional single-input single-output scenario is provided by means of analytical and computer simulation results, showing a promising improvement in error rates when the relay is introduced.