Bluetooth

Abstract: This paper describes a combined power and throughput performance study of WiFi and Bluetooth usage in smartphones. The study reveals several interesting phenomena and tradeoffs. The conclusions from this study suggest preferred usage patterns, as well as operative suggestions for researchers and smartphone developers.

Abstract: Vehicles are being revolutionized by integrating modern computing and communication technologies in order to improve both user experience and driving safety. As a result, vehicular systems that used to be closed systems are opening up various interfaces, such as Bluetooth, 3G/4G, GPS, etc., to the outside world, thus introducing new opportunities for cyber attacks. It has been recently demonstrated that modern vehicles are vulnerable to several remote attacks launched through Bluetooth and cellular interfaces, allowing the attacker to take full control of the vehicle. The common root cause of these attacks is the lack of message authentication for the vehicle's internal bus system, called Controller Area Network (CAN). In this work, we propose VeCure - a practical security framework for vehicular systems, which can fundamentally solve the message authentication issue of the CAN bus. VeCure is designed to be compatible with existing vehicle system architectures, and employs a trust group structure and a novel message authentication scheme with offline computation capability to minimize online message processing delay and deployment cost. We built a proof-of-concept prototype on a testbed using Freescale's automotive development boards. The experimental results show that VeCure only introduces 50us additional delay to process a message, which is at least 20-fold faster than any existing solution.

Abstract: A four-levels hierarchical wireless body sensor network (WBSN) system is designed for biometrics and healthcare applications. It also separates pathways for communication and control. In order to improve performance, a communication cycle is constructed for synchronizing the WBSN system with the pipeline. A low-power adaptive process is a necessity for long-time healthcare monitoring. It includes a data encoder and an adaptive power conserving algorithm within each sensor node along with an accurate control switch system for adaptive power control. The thermal sensor node consists of a micro control unit (MCU), a thermal bipolar junction transistor sensor, an analog-to-digital converter (ADC), a calibrator, a data encoder, a 2.4-GHz radio frequency transceiver, and an antenna. When detecting ten body temperature or 240 electrocardiogram (ECG) signals per second, the power consumption is either 106.3 ?W or 220.4 ?W. By switching circuits, multi sharing wireless protocol, and reducing transmission data by data encoder, it achieves a reduction of 99.573% or 99.164% in power consumption compared to those without using adaptive and encoding modules. Compared with published research reports and industrial works, the proposed method is 69.6% or 98% lower than the power consumption in thermal sensor nodes which consist only of a sensor and ADC (without MCU, 2.4-GHz transceiver, modulator, demodulator, and data encoder) or wireless ECG sensor nodes which selected Bluetooth, 2.4-GHz transceiver, and Zigbee as wireless protocols.

Abstract: The Internet of Things (IoT) is a new communication paradigm that can connect elements from various fields through the Internet. One of the most attractive IoT applications is in the modern healthcare area, as the traditional healthcare system has an increasing demand for social resources, including doctors, nurses, hospital beds, and health monitoring devices. In this article, the design of a compact wearable sensor patch is presented for measurements of different physiological signals, such as the electrocardiogram (ECG), photoplethysmography (PPG), and body temperature. As ECG and PPG sensors are integrated with the same device, the proposed sensor patch can be used to estimate blood pressure (BP) continuously based on the pulse arrival time (PAT) without extra wires and devices. The sensor patch consists of a center board for signal acquisition and processing, a power board for energy supply and charging batteries, and three sensors for vital signs monitoring. All the components are designed in a rigid-flex structure, which can be easily attached to the human body for remote health monitoring applications. The sensors can be detached from the center board for customized measurements of a certain physiological signal (e.g., ECG) to reduce power consumption. Experiments are conducted to validate the performance of the proposed sensor patch by comparison with a commercial reference device. With the integration of a miniaturized Bluetooth low-energy (BLE) module, the proposed sensor system can transmit physiological measurements wirelessly to a gateway. Data encryption is applied on both the sensor patch and gateways to protect data for privacy and security purposes during transmission. Both a mobile gateway (based on smartphones) and a fixed gateway (based on portable computers) are designed as the bridge between the wearable sensor system and the Internet cloud, where health data can be stored and further analyzed. The experimental results demonstrate the feasibility of the overall platform for IoT-connected healthcare applications.