Narrow Results

Security is a concept which people recognize as important, yet regularly ignore for reasons such as cost or design constraints. The world is quickly shifting towards the wireless with phenomena akin to the Internet of Thing (IoT) accelerating this progression. Technologies like Bluetooth Low Energy and Radio Frequency Identification are greatly entwined with this trend, and research has been made into reinforcing protection methods. However, security is a choice made by the designer and more often than not is given decreased priority. With the improved creativity and sophistication of malicious exploits this is becoming far less acceptable. Theft of data is trivial for a user with the correct skillset and will be successful without proper defences. Further research needs to be done in the field, and encouraging consistent security practices is an appropriate start.

China accounts for more than 22% of the total energy consumption worldwide. Building energy consumption, among which consumption in public buildings was about 40% took the second place. With the problems of high energy waste, error rate and complexity of the control systems available, an indoor intelligent lighting system based on occupants’ location is proposed in this paper to improve the energy efficiency of the current lighting systems indoors. The transmission model of electromagnetic wave in free space is optimized in both aspects of reference signal strength and attenuation coefficient radiation in complex environment dynamically based on which occupants’ positions are obtained. The smart lighting system will turn on or off corresponding lights adaptively to provide a more energy efficient platform. Experimental results show that the proposed system is able to improve the energy efficiency of indoor lighting by at least 15%, with a lower error rate below 2% compared with the existing lighting systems based on voice control.

Bluetooth utilizes fast frequency hopping to mitigate interference from other wireless devices and other Bluetooth piconets that share the same frequency range. However, it still cannot avoid the interference between piconets entirely. In our simulation, we observed that the inter-piconet interference can significantly degrade the system throughput by more than 10%. The system throughput within a piconet can be improved by a proper arrangement of the segmentation/reassembling (SAR) policy and a good selection of MAC scheduling protocols. Many SAR policies and MAC scheduling protocols were proposed, but none of them takes the inter-piconet interference into consideration. In this paper, we study the impact of the interference on the performance of TCP traffic over a Bluetooth scatternet with multiple overlapping piconets. To alleviate the impact, we propose interference-aware SAR policies as well as the interference-aware MAC scheduling protocols. The simulation results show that our schemes help reduce the impact of the inter-piconet interference by more than 15%.

In this paper, a digitally programmable OTA-based multi-standard receiver baseband chain is presented. The multi-standard receiver baseband chain consists of two programmable gain amplifiers (PGA1 and PGA2) and a fourth-order LPF. The receiver is suitable for Bluetooth/UMTS/DVB-H/WLAN standards. Three different programmable OTA architectures based on second generation current conveyors (CCIIs) and Current Division Networks (CDNs) are discussed. The programmable OTA with the lowest power consumption, moderate area and good linearity — better than -50 dB HD3 — is selected to realize the multi-standard baseband receiver chain. The power consumption of the receiver chain is 6 mW. The DC gain varies over a 68 dB range with 1 MHz to 13.6 MHz programmable bandwidth. The receiver baseband chain is realized using 90 nm CMOS technology model under ±0.5 V voltage supply.

The capability of seamlessly switching between two communication protocols will be very important for communication devices of the future, since it allows the end users to judiciously use whichever network is appropriate, depending on cost, signal strength or other factors such as the amount of battery life left on the device. This paper presents the groundbreaking idea of a Seamless Protocol Switching Layer (SPSL) on a hardware and software level to solve this problem. In addition, the SPSL concept is implemented by developing a prototype application, a Smart Video Phone, built using Intel XScale-based PXA255 board and ARM Linux as the operating system that can seamlessly switch between IEEE 802.11 and Bluetooth technologies. Experiments show that if the signal of the Bluetooth signal goes below 40%, the switching to Wireless-Fidelity (Wi-Fi) happens if it is available.

The integration level of RFICs has exhibited dramatic progress during the last decade. For example, Si-based single-chip GSM/GPRS/DCS/PCS, WLAN, Bluetooth and DECT transceivers have all been reported in the past few years. The next major milestone for integration will be the single-chip RF-system-on-a-chip (i.e. "RF-SoC") product that supports multi-band multi-standard cellular standards (such as UMTS/GSM/GPRS/CDMA2000) with the wireless personal-area-network (PAN) and wireless-local-area-network (WLAN) features. To achieve this high level of RFIC integration, one has to choose radio circuit architectures that require a minimal number of external components, together with a judicious selection of the IC technology for implementation. Recent design trends on highly integrated wireless RFIC transceivers are reviewed, with emphasis on the RF-SoC performance trade-offs impacted by the chip-level architectural selection and the device-level technology choice. The major roadblocks to single-chip radio RFIC designs are briefly discussed.

Recently, using a wireless technology to transmit physiological signals, such as electrocardiogram (ECG), for a home tele-care system has received great attention. Although wireless transmission can provide the mobility advantage, it has to cope with the potential problem in limited bandwidth and induced interference. In this study, we propose an integration design in which a state-of-the-art compression algorithm called SPIHT (set partitioning in hierarchical trees) is combined with an unequal error protection scheme, to solve the problem for the ECG signals transmitted in Bluetooth packets. In this design, part of the SPIHT bit stream behaves like a fragile variable length code and needs a stronger protection with the forward error correction (FEC) code; the rest of the bit stream is lightly protected by the code. The simulation results show that the 2/3-rate FEC code in DM packets works effectively without the proposed scheme when the interference is fairly small. However, with the proposed scheme, the quality of received ECG signals is usually much better than that without the scheme when stronger interferences from fading channels and wireless LAN are encountered in an indoor environment. Consequently, the important features of an ECG waveform, such as P wave, QRS complex, and T wave, could be well preserved at a receiver site with clinically acceptable reconstruction quality. In addition, the data compression method in the proposed scheme can save total transmission power and time, and therefore reduce its potential interferences to other wireless devices.

A light and portable-type wireless physiological signal retrieving system has always been a medical personnel's dream. To fulfill this dream, this paper investigates a feasible method to create a wireless-type physiological signal measuring system using a PDA and the bluetooth technology. The proposed system will reduce the service costs and raise the service efficiency for current medical care systems. The waveforms and data of physiological signals, such as electrocardiograms (ECGs), phonocardiograms (PCGs), electroencephalograms (EEGs), body temperatures, and so forth, are always the vital references for medical doctors to diagnose the patients' body condition. The traditional physiological signal measuring instruments or devices possess some shortcomings, such as high prices, bulky dimensions, ill-portability and excessive connection cables. In contrast, the proposed wireless-type physiological signal measuring system, being able to get rid of said shortcomings, holds apparent advantages in service costs and service efficiency and, hence, shall be the trend for the future. This study has completed some tests in ECG, PCG, and body temperature measurements. The proposed prototype system has successfully using the bluetooth technology to invisibly transmit and receive physical signals through the air.

Bluetooth is a suitable technology to support soft real-time applications like multimedia streams at the Personal Area Network (PAN) level. In this paper, we evaluate the worst-case deadline failure probability (WCDFP) of Bluetooth packets under co-channel interference as a way to provide statistical QoS guarantees.

The cornerstone of the Indian economy is the agricultural sector. A large percentage of individuals around the world — more than 40% — have agriculture as their primary line of employment. The advancement of autonomous vehicles in agriculture has gained considerable spotlight in recent years. Soil quality is unaltered by robotization, which also significantly reduces manpower expenses and boosts overall productivity. The machinery described in this project is proficient at performing several farming operations at once. An environmentally safe source of energy is utilized by this equipment: Energy from the sun’s radiation is accumulated and transformed into electrical energy, and a direct current motor then transforms this electrical power into mechanical power to rotate an anchor during a digging operation. For irrigation operations and seed sowing, respectively, we deploy seed hoppers and water reservoirs. The machine can change its course and maneuver over varied ground contours, excavate, sow seed, and water the ground. It also decreases the expense of planting seeds and the manpower required.

Bluetooth is a short-range, packet radio system designed to connect various low power, resource constrained devices. Devices form autonomous ad hoc networks of up to 8 active devices, referred to as piconets. Piconets may be interconnected by one or more bridge devices to form a scatternet. Bridges have an added responsibility of sharing their active time between the piconets that they are connected to. This could lead to a disproportionate energy usage pattern at the bridge nodes, as compared to other nodes in the piconet. When a bridge node dies, it could create a partition in the scatternet, leading to packet loss and delays. In this paper, we consider two related issues. 1. Enhance the lifetime of the scatternet by simply improving the lifetime of the bridge. 2. Extend the lifetime of the bridge by making a fair distribution of the role of being a bridge among different devices in the piconet. To achieve these goals, we propose a policy for managing bridge devices based on both prevalent traffic conditions and the energy available at devices using a weighted credit scheme.

In this paper, we describe a novel architecture to enable a secure communication among mobile devices using different wirelesstechnologies like wireless LAN, Bluetooth, cellular systems or even infrared. Making use of the combination of these technologies for the data transmission and for the signaling of the communication, we analyze several scenarios with increasing complexity. The complete picture appears in the last scenario where all technologies are involved and the network is composed of heterogeneous mobile nodes. The paper also presents a solution for the setup of a secured communication channel (i.e. a Virtual Private Network connection) between several heterogeneous mobile nodes controlled by the cellular network operator. The mobile nodes can be either cellular aware or non-cellular aware in this framework. We propose to setup the heterogeneous network communications via the cellular network using the cellular aware nodes.

The Bluetooth standard is considered a promising technology for implementing ad-hoc networks. This paper addresses issues related to Bluetooth performance in Nakagami-m fading channels. This distribution allows a better channel characterization for mobile and wireless communications. The throughput of Bluetooth links using asynchronous packets is investigated. Useful relations between packet error rate and node distances are derived. These results can be used as benchmarks for performance analysis or incorporated into Bluetooth network simulation tools. As an example, we evaluate by computer simulation the performance of a scatternet in a Nakagami fading scenario.

Feeding System of the traditional Drop Analyzer is controlled by independent manner. This method of controlling has high cost and complex operation. This paper designs a controlling system of the Drop Analyzer which is based on Bluetooth. It is composed of S5pv210 embedded processor and Feeding System. S5pv210 embedded processor communicates with the Feeding System through HC-06 Bluetooth module. The HC-06 Bluetooth module converts Bluetooth signal to serial signal. The Feeding System uses STC12C2052AD to receive serial signal from HC-06 module and control stepper motor. Application software is developed on Android devices. We can control the stepper motor flexibly by the user interface.

Universities are experiencing significant growth in international students' enrollment, which makes the teaching innovations are urgently needed. Practical and systematic experiments are suitable for some traditional theory teaching courses, like data communication, control theory, communication theory, and digital communication, et. al. However, they are not suitable to the emerging enrollment of international undergraduate students, for the complex theories cannot easily absorbed or grasped by different education-background students. An android based “Radio Frequency identity” (RFID) “Objects' Searching System” (OSS) is designed to demonstrate the transmission and controlling of signals through the user-friendly Android apps, and also explain easily the information exchange and signal processing. The proposed OSS has a flexible mobile keyboard control center, which is suitable to non-native international students to operate. Also, the proposed android RFID system combines Bluetooth, serial, and SPI communications together, which are designed to promote the efficiency of finding small objects and has preliminary higher level network interfaces for the students to extend the system functions and further improve the efficiency.