Nick Timmons

Letterkenny Institute of Technology | LYIT · WiSAR Lab

The design and development of a switched beam antenna at 2.45 GHz industrial, scientific and medical band for wireless sensor network applications is presented in this paper. The antenna is capable of switching the beam pattern in directions such as in the boresight direction 0°, ±63° and as a bidirectional endfire radiator (±85°). The directive ga...

The design, fabrication, and performance analysis of a Polyimide Loop antenna is presented. This design is particularly intended for wearable wireless body area network applications where safe, conformal, and flexible antennas are desirable. The performance of the Polyimide Loop antenna was compared to that of a standard copper wire loop antenna. B...

The design, fabrication, and performance analysis of a 2.45GHz dipole antenna embedded in a PDMS substrate is presented. This design is particularly intended for wearable wireless body area network applications where safe, conformal, and flexible antennas are desirable. The performance of the PDMS antenna was measured and compared to that of a stan...

In this paper, we investigate the performance of a 2.45 GHz annular cylindrical dielectric resonator antenna when mounted on the human torso. An impedance bandwidth of 3.7% was obtained centered at 2.45 GHz. The antenna was designed to achieve an omnidirectional radiation pattern similar to a monopole antenna which can effectively couple the electr...

This paper presents the development of a new stacked circular patch antenna at 2.45 GHz for communication between sensor nodes attached at different locations on a human body in medical body area networks. The antenna exhibits a bandwidth of 3.7 % centered at 2.45 GHz, when placed (2mm) above from a muscle tissue phantom. The antenna gives a radiat...

Unreliability is an inherent property of wireless links. In opportunistic networks, these intermittent links are exploited, instead of mitigated, by temporal and/or spatial diversities in order to improve the network performance such as energy efficiency, delay, throughput and so on. Simulation is always an important method for the research in this...

A gain enhanced planar Yagi-Uda antenna with pattern reconfiguration is presented. The prototype provides an omnidirectional pattern as well as a high-gain directive pattern, which can be reconfigured on two orthogonal planes. For the first time, the principle of a Yagi-Uda antenna combined with pattern reconfiguration is implemented without comple...

A microstrip-fed truncated monopole antenna with radiation pattern and polarization reconfigurability is presented. The antenna fabricated on a substrate of dielectric constant 4.4 and thickness 1.6 mm is highly compact with an overall dimension of only 0.25λs × 0.25λs. The pattern of the antenna is omnidirectional and is reconfigurable with the po...

Distribution (144 pages) in accordance with Need To Know

In the context of Smart City environments, wireless sensor networking is playing a major role when enabling the utilization of networked infrastructures to introduce or improve a wide variety of services to be available to the citizens. How nodes communicate with each other is a key issue in these types of networks. This work presents a simple but...

In low power wireless body area networks it is envisaged that there will be communication between on-body devices and wireless nodes placed in the environment (sensed environment) to provide a range of applications including health monitoring. However, there remain major challenges to realise this scenario such as decisions on the optimal node loca...

Wireless Sensor Networks (WSNs) are gaining an increasing industry wide adoption. However, there remain major challenges such as network dimensioning and node placement especially in Built Environment Networks (BENs). Decisions on the node placement, orientation, and the number of nodes to cover the area of interest are usually ad-hoc. Ray tracing...

A microstrip-fed ground modified compact antenna suitable for the 2.4GHz band is presented. The radiation pattern of the antenna can be selected, for either directional or omnidirectional. Moreover the directive pattern can be switched by 180 degree using a simple switching circuit. The prototype is fabricated on a substrate of dielectric constant...

This paper revisits the problem of multisession multicast tree construction with bandwidth allocation in wireless sensor networks. Previous work has shown that when the goal is to find multicast routing tree, the problem becomes NPcomplete. In this work, we present a heuristic Energy-Efficient Multisession Multicast protocol (EEMM) that uses fuzzy...

In this paper, we study the problem of routing, bandwidth and flow assignment in Wireless Body Area Networks (BANs). Our solution considers BAN for real-time data streaming applications, where the real-time nature of data streams is of critical importance for providing a useful and efficient sensorial feedback for the user while system lifetime sho...

This paper tackles the problem of multi-session multicast tree construction with bandwidth and rate allocation in wireless sensor networks. Previous work has shown that when the goal is to find multicast trees with minimum transmission cost, the problem becomes NP-complete. In this work, we present a heuristic Multisession Multicast Routing and Ban...

In this work, we focus on Body Area Networks (BANs) for real-time data streaming applications, where the realtime nature of data streams is of critical importance for providing a useful and efficient sensorial feedback for the user while system lifetime should be maximized. Thus, bandwidth, throughput and energy efficiency of the communication prot...

We present an adaptive joint routing and bandwidth allocation scheme for traffic streaming in Body Area Networks (BAN). Our solution considers BAN for real-time data streaming applications, where the real-time nature of data streams is of critical importance for providing a useful and efficient sensorial feedback for the user while system lifetime...

A Centre fed slot dipole antenna excited with coplanar waveguide feed is presented and discussed. The very high impedance of an open ended coplanar waveguide (CPW) is made lower by off centering the feed position, optimizing the feed length and by using a T-shaped feed. All presented prototypes are fabricated on a substrate of dielectric constant 4...

In Body Area Networks (BANs), quality of service is needed to provide reliable data communication over prioritized data streams coming from energy constrained sensors attached to, or possibly implanted in, patients. In this work, we focus on BAN for real-time data streaming applications, where the real-time nature of data streams is of critical imp...

Medical body area networks will employ a range of implantable and body worn devices to support a wide range of applications with diverse QoS requirements. The IEEE 802.15.6 working group is developing a communications standard for low power devices operating on, in and around the body and medical devices are a key application area of the standard....

Wireless Body Area Networks (BANs) have the ability of gathering and sending on-body measurements to a terminal. Autonomous nodes are deployed on the body to monitor vital signs and environmental parameters. The IEEE 802.15.6 standard mainly specifies physical and medium access for BANs. Routing is discussed as part of the link layer and multihop i...

Developments over the past decade in wireless and sensor technology have resulted in the growth of new applications for Wireless Sensor Networks (WSNs). One of the most popular areas for WSNs is the Built Environment Network (BEN), which comprises a wide variety of applications such as energy monitoring/smart homes, surveillance and healthcare appl...

Interest in on-body communication channels is growing as the use of wireless devices increases in medical, consumer and military sensor applications. This paper presents an experimental investigation and analysis of the narrowband on-body propagation channel. This analysis considers each of the factors affecting the channel during a range of statio...

In ultra-low data rate wireless sensor networks (WSNs) waking up just to listen to a beacon every superframe can be a major waste of energy. This study introduces MedMAC, a medium access protocol for ultra-low data rate WSNs that achieves significant energy efficiency through a novel synchronisation mechanism. The new draft IEEE 802.15.6 standard f...

Body Area Networks (BANs) are an emerging area of wireless personal communications. The IEEE 802.15.6 working group aims to develop a communications standard optimised for low power devices operating on, in or around the human body. IEEE 802.15.6 specifically targets low power medical application areas. The IEEE 802.15.6 draft defines two main chan...

Wireless Sensor Networks (WSNs) are gaining an increasing industry wide adoption. However, there remain major challenges such as network dimensioning and node placement especially in Built Environment Networks (BENs). Decisions on the node placement, orientation, and the number of nodes to cover the area of interest are usually ad-hoc. Ray tracing...

A topology governs the logical connectivity b etween the nodes in the network. Development of Wireless Body Area Networks (WBANs) requires applying tailored technologies to countermeasure the effects of wireless propagation while satisfying constrains imposed by hardware. Important part of this process is topology selection as it affects the develo...

Technological advancements have made possible the emergence of Body Area Networks (BANs). There are numerous on-body channel characterizations in the literature performed on a phantom or a single human subject. In this paper, using multiple subjects, we consider the effect of body shape and gender on the on-body channel. A characterization of a nar...

The emerging area of body area networks (BAN) imposes challenging requirements on hardware and software to achieve the desired lifetimes for certain devices such as long term medical implants. In this paper, we propose a novel approach to the measurement and characterisation of the energy consumption of BAN devices. The approach uses a low cost ene...

Medical body area networks will employ both implantable and bodyworn devices to support a diverse range of applications with throughputs ranging from several bits per hour up to 10 Mbps. The challenge is to accommodate this range of applications within a single wireless network based on a suitably flexible and power efficient medium access control...

For the first time, this paper presents an analysis of the performance of the IEEE 802.15.4 low power, low data rate wireless standard in relation to medical sensor body area networks. This is an emerging application of wireless sensor networking with particular performance constraints, including power consumption, physical size, robustness and sec...