Millimetre-wave (mm-wave) radar sensing offers a promising IoT-enabled approach for continuous and unobtrusive health monitoring in home environments. Conventional remote monitoring methods, including wearable devices and mobile applications, often rely on user engagement, which introduces compliance, comfort, and maintenance challenges that limit their long-term utility. This paper presents an IoT-based mm-wave radar system deployed in a residential care apartment and evaluated over a six-month feasibility case study involving a single 83-year-old participant, demonstrating stable operation and real-world performance for continuous in-home monitoring. The radar nodes operate as a passive, privacy-preserving sensing infrastructure that extracts behavioural parameters and digital biomarkers such as room occupancy, movement patterns, gait speed, and activity levels without requiring user interaction. Across the deployment period, the system maintained high operational uptime (78.50%) and reliable data transmission (0.02% error), supporting uninterrupted minute-level monitoring. The system consistently captured mean daily distances moved of 38.6 m in the bedroom and 39.1 m in the living room. Gait speed distributions revealed temporal and spatial variability, with daily median speeds ranging from 0.25 to 0.55 m/s and a mean daily maximum speed of 0.78 m/s. These findings demonstrate the technical feasibility of long-term, maintenance-free operation within an IoT framework in a real-world residential setting and highlight the potential of mm-wave radar sensing for privacy-preserving, continuous in-home monitoring.

Falls among the older adults pose a global health concern, necessitating innovative approaches for timely and effective falls risk screening. Aiming to develop a real-time falls risk screening tool, this study explores the integration of millimeter-wave (mmWave) radar technology with the Timed Up and Go (TUG) test, which is a widely used screening tool that combines parameters measuring a person’s dynamic balance and functional mobility. Radar technology has emerged as a promising tool for non-intrusive, continuous monitoring of movements – including gait patterns and mobility – in real-life scenarios. By leveraging Frequency Modulated Continuous Wave (FMCW) radar, the study assesses its performance against video recordings in TUG completion time measurement. The completion time, conventionally measured manually with a timer in clinical settings, was derived from radar measurements using two different methods based on distance, and micro-Doppler (i.e. velocity). Results indicate radar’s superior accuracy in distance-based measures with 3.48% error and a correlation of 0.9996, surpassing manual timing (4.26% error, 0.9960 correlation) and demonstrating viability for falls risk screening protocols. The velocity-based determination performed slightly poorer (6.49% error, 0.9936 correlation), which is attributable to the very high sensitivity of the radar in detecting small motions, such as shuffling in a chair, that are not a part of the TUG sequence. This study contributes to healthcare technology innovation, emphasising radar’s transformative role beyond falls risk assessment. The precision of radar-based measurements opens avenues for enhanced diagnostics, monitoring, and personalised care.

The radio frequency identification (RFID) has emerged Internet of Things (IoT) into the identification of things. This paper presents, a low-cost smart refrigerator system for future IoT applications. The proposed smart refrigerator is used for automatic billing and restoring of beverage metallic cans. The metallic cans can be restored by generating a product shortage alert message to a nearby retailer. To design a low-cost and low-profile tag antenna for metallic items is very challenging, especially when mass production is required for item-level tagging. Therefore, a novel ultrahigh frequency (UHF) RFID tag antenna is designed for metallic cans by exploiting the metallic structure as the main radiator. Applying characteristics mode analysis, we observed that some characteristic modes associated with the metallic structure could be exploited to radiate more effectively by placing a suitable inductive load. Moreover, a low cost, printed (using conductive ink) small loop integrated with meandered dipole used as an inductive load, which was also connected with RFID chip. The 3-dB bandwidth of the proposed tag covers the whole UHF band ranging from 860 to 960 MHz when embedded with metal cans. The measured read range of the RFID tag is more than 2.5 m in all directions to check the robustness of the proposed solution. To prove the concept, a case study was performed by placing the tagged metallic cans inside a refrigerator for automatic billing, 97.5% tags are read and billed successfully. This paper paves the way for tagging metallic bodies for tracking applications in domains ranging from consumer devices to infotainment solutions, which enlightens a vital aspect for the IoT.

Fitness trackers not just provide easy means to acquire physiological data in real-world environments due to affordable sensing technologies, they further offer opportunities for physiology-aware applications and studies in HCI; however, their performance is not well understood. In this paper, we report findings on the quality of 3 sensing technologies: PPG-based wrist trackers (Apple Watch, Microsoft Band 2), an ECG-belt (Polar H7) and reference device with stick-on ECG electrodes (Nexus 10). We collected physiological (heart rate, electrodermal activity, skin temperature) and subjective data from 21 participants performing combinations of physical activity and stressful tasks. Our empirical research indicates that wrist devices provide a good sensing performance in stationary settings. However, they lack accuracy when participants are mobile or if tasks require physical activity. Based on our findings, we suggest a textitDesign Space for Wearables in Research Settings and reflected on the appropriateness of the investigated technologies in research contexts.

Revolutionary advancement in realizing nanosensors promises unprecedented enhancement of applications in several fields such as health, industry, agriculture, environment, sport, etc. The small size of nano-sensors and their THz band leads to significant constraints in energy, memory, processing, and transmission range. To combat these constraints, recent progress and active research in nano-sensing technology have led to increasing interest in connecting these nano-sensors in a new network technology, the nano-network. Communication in nano-networks still poses a non-trivial challenge owing to the constraint of processing, storage, energy, and communication range capabilities of nano-nodes. Short communication range in the THz band renders direct communication in nano-networks infeasible most of the time. Hence, multihop communication among nano-nodes is currently regarded as the viable solution for nano-network realization. In this paper, we investigate three routing protocols; controlled flooding, CORONA, and Hierarchical AODV. We evaluate the performance of the three protocols with different transmission ranges and network densities.

This paper demonstrates a low profile, compact and conformal antenna design for 5thgeneration (5G) wireless devices. The antenna design incorporates two bandwidth-enhancement techniques of fractal geometry and defected ground structure (DGS). The Koch fractal radiating patch is developed with a DGS coupled coplanar waveguide (CPW) feeding. Highly precise fabrication is performed on a thin Polyethylene Terephthalate (PET) film using the additive manufacturing process of conductive ink-based inkjet printing. The results show that the antenna offers a bandwidth which covers Ka-band (26.5-40 GHz) and a peak realised gain of 9.7 dBi at 39.7 GHz. The integrated aperture in the ground improves the directivity by converging the radiation in the axis orthogonal to the antenna's plane. The proposed flexible antenna is well suited for integration in millimetre-wave (MMW) based wearable and conformal wireless devices.

We present a framework - AWSense - for eased sensing data collection from an Apple Watch wearable device. The framework eases the access, transmission and export of sensing data from the device. This data comprises: heart rate, raw acceleration, and computed device motion. In our demo, we present sample applications built on top of this framework to show its capabilities, of real-time presentation and recording of the sensing data.

In vivo wireless body area networks and their associated technologies are shaping the future of healthcare by providing continuous health monitoring and noninvasive surgical capabilities, in addition to remote diagnostic and treatment of diseases. To fully exploit the potential of such devices, it is necessary to characterize the communication channel, which will help to build reliable and high-performance communication systems. This paper presents an in vivo wireless communication channel characterization for male torso both numerically and experimentally (on a human cadaver) considering various organs at 915 MHz and 2.4 GHz. A statistical path loss (PL) model is introduced, and the anatomical region-specific parameters are provided. It is found that the mean PL in decibel scale exhibits a linear decaying characteristic rather than an exponential decaying profile inside the body, and the power decay rate is approximately twice at 2.4 GHz as compared to 915 MHz. Moreover, the variance of shadowing increases significantly as the in vivo antenna is placed deeper inside the body since the main scatterers are present in the vicinity of the antenna. Multipath propagation characteristics are also investigated to facilitate proper waveform designs in the future wireless healthcare systems, and a root-mean-square delay spread of 2.76 ns is observed at 5 cm depth. Results show that the in vivo channel exhibit different characteristics than the classical communication channels, and location dependence is very critical for accurate, reliable, and energy-efficient link budget calculations.

In this paper, the channel model is proposed to compute the path loss, delay and noise at THz band of interest (0.5 THz ~ 1.5 THz). The results shows that THz band channel is strongly dependent on both the type of the medium and the distance while the concentration of water have a lot of influence because it not only causes attenuation to the THz wave but also introduces non-white noise. Therefore, the proposed model paves the way to the further studies considering more body structures and tissue properties.

The paper presents an initial study of analyzing the propagation of electromagnetic waves at terahertz frequencies inside the human skin tissues in the frequency range 0.8-1.2 THz. The skin model is represented by three layers: stratum corneum (SC), epidermis, and dermis, and the effect of the presence of sweat ducts is also studied. The path loss resulting from the signal propagation between a transmitting antenna, located at the epidermis layer, and a receiving antenna, located at the dermis layer, is analyzed for different distances and different frequencies, in addition to changing the number of sweat ducts. Results show that the path loss through the skin tissues depends on the distance between the transmitter and the receiver, the frequency used, and the number of sweat ducts as the path loss decreases by approximately 1 dB for increasing the number of sweat duct from one duct to two ducts. Moreover, the path loss is statistically studied and its distribution is approximately Gaussian.

Millimeter-wave reconfigurable antennas are predicted as a future of next generation wireless networks with the availability of wide bandwidth. A coplanar waveguide (CPW) fed T-shaped frequency reconfigurable millimeter-wave antenna for 5G networks is presented. The resonant frequency is varied to obtain the 10dB return loss bandwidth in the frequency range of 23-29GHz by incorporating two variable resistors. The radiation pattern contributes two symmetrical radiation beams at approximately ±30o along the end fire direction. The 3dB beamwidth remains conserved over the entire range of operating bandwidth. The proposed antenna targets the applications of wireless systems operating in narrow passages, corridors, mine tunnels, and person-to-person body centric applications.

Parametric probability models are common references for channel characterization. However, the limited number of samples and uncertainty of the propagation scenario affect the characterization accuracy of parametric models for body area networks. In this paper, we propose a sparse nonparametric probability model for body area wireless channel characterization. The path loss and root-mean-square delay, which are significant wireless channel parameters, can be learned from this nonparametric model. A comparison with available parametric models shows that the proposed model is very feasible for the body area propagation environment and can be seen as a significant supplement to parametric approaches.

This paper presents an investigative study of the ranging capabilities of a miniature tapered-slot UWB antenna and an analysis of the influence of the human body on the accuracy of range estimates. The study involves determining how precisely the point-to-point distance between two identical tapered-slot antennas can be deduced through the signal Time-of-Flight from the transmitting antenna to the receiving antenna. Channel Impulse Response and peak detection techniques have been used for range estimation. Both on-body and free-space scenarios have been considered for this study. Very high accuracy is observed in calculating the range estimates between the two antennas, both when the antennas are in free-space and when placed on the human body.

The paper presents the improvement offered by spatial diversity to reduce fading in ultra wideband (UWB) body-centric wireless communication channel in context of second order statistics for five different measured links, i.e., waist-to-chest, waist-to-head, waist-to-wrist, waist-to-ankle and waist-to-back. Average fade duration (AFD) and level crossing rate (LCR) values are presented and compared for diversity combined signal with respect to branch signals. In addition AFD and LCR of diversity combined signals are also compared for five different on-body channels and for three different locations in an indoor environment. Result and analysis of second order channel parameters shows the importance of considering these parameters when designing an enhanced body-area network system.

The paper presents a subject-specific radio propagation study and system modeling in wireless body area networks using a simulation tool based on the parallel finite-difference time-domain technique. This technique is well suited to model the radio propagation around complex, inhomogeneous objects such as the human body. The impact of different digital phantoms in on-body radio channel and system performance was studied. Simulations were performed at the frequency of 3-10 GHz considering a typical hospital environment, and were validated by on-site measurements with reasonably good agreement. The analysis demonstrated that the characteristics of the on-body radio channel and system performance are subject-specific and are associated with human genders, height, and body mass index. Maximum variations of almost 18.51% are observed in path loss exponent due to change of subject, which gives variations of above 50% in system bit error rate performance. Therefore, careful consideration of subject-specific parameters are necessary for achieving energy efficient and reliable radio links and system performance for body-centric wireless network.

The paper aims to investigate the optimum locations for ultra wideband (UWB) nodes placement on the body. The performance of UWB radio propagation links is experimentally investigated by considering communications between body-worn base units and off-body access points. Radio channel parameters are derived and analysed for different sectors of the human body. System-level modelling, based on signal to noise ratio (SNR) and bit error rate (BER) is analytically performed on the basis of multi band orthogonal frequency division multiplexed (OFDM) system.

This paper presents an experimental investigation of off-body radio propagation channels based on commercially available UWB wireless tags. The tags operate at frequency band of 5.9~7.2 GHz. A measurement campaign was performed both in the chamber and in an indoor environment for comparison. The path loss for nine different channels is shown with parameters describing the radio channel derived through statistical analysis.