IEEE802.15.4 is a standard which specifies the physical and medium access control for low-rate, low-cost, low-power Wireless Personal Area Networks (LR-WPANs). However, this protocol suffers from several types of collisions; In spite of being able to avoid data packets colliding with each other by using CSMA/CA, the risk of beacon collisions still remains specially in a cluster-tree network top...

IEEE802.15.4 is a standard which specifies the physical and medium access control for low-rate, low-cost, lowpower Wireless Personal Area Networks (LR-WPANs). However, this protocol suffers from several types of collisions; In spite of being able to avoid data packets colliding with each other by using CSMA/CA, the risk of beacon collisions still remains specially in a cluster-tree network topo...

Research shows that context is important to the privacy perceptions associated with technology. With Bluetooth Low Energy beacons, one of the latest technologies for providing proximity and indoor tracking, the current identifiers that characterize a beacon are not sufficient for ordinary users to make informed privacy decisions about the location information that could be shared. One solution ...

A DNA hybridization based optical detection platform for the detection of foodborne pathogens has been developed with virtually zero probability of the false negative signal. This portable, low-cost and real-time assaying detection platform utilizes the color changing molecular beacon as a probe for the optical detection of the target sequence. The computer-controlled detection platform exploit...

This work describes a genetic algorithm based approach to approximate an optimal path for a mobile beacon node in a grid of stationary wireless sensors. As the beacon moves over the field of sensors it broadcasts its location. Sensors that are currently in the proximity of the beacon will receive this communication and can then use several of these messages to compute estimates on their locatio...

We have designed a new class of molecules, which we term aptamer beacons, for detecting a wide range of ligands. Similar to molecular beacons, aptamer beacons can adopt two or more conformations, one of which allows ligand binding. A fluorescence-quenching pair is used to report changes in conformation induced by ligand binding. An anti-thrombin aptamer was engineered into an aptamer beacon by ...

Spatial localization is an important building block for wireless sensor networks. Beacons that know their position and serve as reference are a vital aspect of nearly every localization system. In this paper, we look at dense beacon placement, which has a significant impact on the overall quality of localization. Based on the premise that uniformly dense beacon placement is not practical, we mo...

Indoor environments present opportunities for a rich set of location-aware applications such as navigation tools for humans and robots, interactive virtual games, resource discovery, asset tracking, location-aware sensor networking etc. Typical indoor applications require better accuracy than what current outdoor location systems provide. Outdoor location technologies such as GPS have poor indo...

IEEE 802.15.4 is a new standard uniquely designed for low rate wireless personal area networks (LRWPANs). It targets low data rate, low power consumption and low cost wireless networking, and offers device level wireless connectivity. We develop an NS2 simulator for IEEE 802.15.4 and conduct several sets of experiments to study its various features, including: (1) beacon enabled mode and non-be...