Reliability Evaluation and Analysis of Mobile Ad Hoc Networks

The paper addresses the reliability problem of mobile ad hoc networks under link and node failure model. Node reliability is calculated as a function of no. of neighbor nodes, packet success rate, and device type and packet size. The presence of a link between any node pair is binary and its reliability is computed considering the distance between nodes and signal-to-noise ratio (SNR). An efficient algorithm is proposed to analyze and calculate the reliability of mobile ad hoc networks considering multiple routes from source and destination nodes. The effect of different parameters on node reliability and link reliability are analyzed and discussed. The network is simulated and analyzed using INET frame work. Reliability of two distinct cases of this simulation is evaluated. The simulated results and discussions ensure that evaluation of the reliability of any mobile ad hoc networks can be done easily and in an efficient manner by the proposed method

On Dependable Wireless Communications through Multi-Connectivity

The realization of wireless ultra-reliable low-latency communications (URLLC) is one of the key challenges of the fifth generation (5G) of mobile communications systems and beyond. Ensuring ultra-high reliability together with a latency in the (sub-)millisecond range is expected to enable self-driving cars, wireless factory automation, and the Tactile Internet. In wireless communications, reliability is usually only considered as percentage of successful packet delivery, aiming for 1 − 10⁻⁵ up to 1 − 10⁻⁹ in URLLC

Ultra-Wideband CMOS Transceiver Front-End for Bio-Medical Radar Sensing

Since the Federal Communication Commission released the unlicensed 3.1-10.6 GHz frequency band for commercial use in early 2002, the ultra wideband (UWB) has developed from an emerging technology into a mainstream research area. The UWB technology, which utilizes wide spectrum, opens a new era of possibility for practical applications in radar sensing, one of which is the human vital sign monitoring. The aim of this thesis is to study and research the possibility of a new generation humanrespiration monitoring sensor using UWB radar technology and to develop a new prototype of UWB radar sensor for system-on-chip solutions in CMOS technology. In this thesis, a lowpower Gaussian impulse UWB mono-static radar transceiver architecture is presented. The UWB Gaussian pulse transmitter and receiver are implemented and fabricated using 90nm CMOS technology. Since the energy of low order Gaussian pulse is mostly condensed at lower frequency, in order to transmit the pulse in a very efficient way, higher order Gaussian derivative pulses are desired as the baseband signal. This motivates the advancement of the design into UWB high-order pulse transmitter. Both the Gaussian impulse UWB transmitter and Gaussian higher-order impulse UWB transmitter take the low-power and high-speed advantage of digital circuit to generate different waveforms. The measurement results are analyzed and discussed. This thesis also presents a low-power UWB mono-static radar transceiver architecture exploiting the full benefit of UWB bandwidth in radar sensing applications. The transceiver includes a full UWB band transmitter, an UWB receiver front-end, and an on-chip diplexer. The non-coherent UWB transmitter generates pulse modulated baseband signals at different carrier frequencies within the designated 3-10 GHz band using a digitally controlled pulse generator. The test shows the proposed radar transceiver can detect the human respiration pattern within 50 cm distance. The applications of this UWB radar sensing solution in commercialized standard CMOS technology include constant breathing pattern monitoring for gated radiation therapy, realtime monitoring of patients, and any other breathing monitoring. The research paves the way to wireless technology integration with health care and bio-sensor network

Interoperabilidad dinámica de servicios mediante comunicaciones inalámbricas bluetooth en entornos urbanos y sistemas inteligentes de transporte

La evolución en la capacidad de los sistemas empotrados y, en particular, de aquellos sistemas embarcados en terminales móviles, hace posible que hoy en día puedan ofrecer servicios avanzados que antes sólo se concebían para redes y sistemas de mayor envergadura tales como PCs conectados a través de Internet. En el nuevo escenario de los servicios en movilidad las tecnologías inalámbricas juegan un papel fundamental, y se complementan con tecnologías procedentes de otros ámbitos, como el middleware, para dar soporte a los servicios. El uso de estas tecnologías en entornos urbanos y sistemas de transporte inteligente conlleva una serie de ventajas que se manifiestan, por ejemplo, en la posibilidad de ofrecer servicios dependientes del contexto o en la interoperabilidad de servicios. Entre esas tecnologías destacan Bluetooth, como base para las comunicaciones inalámbricas y CORBA, como plataforma middleware. Si bien, las características de ambas tecnologías son bastante adecuadas al tipo de entornos mencionado, es necesario acomenter ciertas adaptaciones que tengan en cuenta las particularidades y situaciones que se dan en estos entornos y que garanticen un correcto acceso a los servicios y una gestión inteligente de las conexiones. Sobre la base de Wireless CORBA, una de las iniciativas que une Bluetooth y CORBA, en esta Tesis se plantean modificaciones y se definen nuevos elementos que permiten su utilización en entornos urbanos y sistemas inteligentes de transporte. La definición del sistema se acompaña de estudios y recomendaciones que ayudan a optimizar el rendimiento en función del tipo de servicio y las condiciones del entorno. El sistema planteado supone una base común para el desarrollo de nuevos servicios, y prueba de ello lo constituyen las aplicaciones implementadas, que demuestran la viabilidad práctica del mismo