Allocation of control and data channels for Large-Scale Wireless Sensor Networks

Both IEEE 802.15.4 and 802.15.4a standards allow for dynamic channel allocation and use of multiple channels available at their physical layers but its MAC protocols are designed only for single channel. Also, sensor's transceivers such as CC2420 provide multiple channels and as shown in [1], [2] and [3] channel switch latency of CC2420 transceiver is just about 200$\mu$s. In order to enhance both energy efficiency and to shorten end to end delay, we propose, in this report, a spectrum-efficient frequency allocation schemes that are able to statically assign control channels and dynamically reuse data channels for Personal Area Networks (PANs) inside a Large-Scale WSN based on UWB technology

A Photo-Based Mobile Crowdsourcing Framework for Event Reporting

Mobile Crowdsourcing (MCS) photo-based is an arising field of interest and a trending topic in the domain of ubiquitous computing. It has recently drawn substantial attention of the smart cities and urban computing communities. In fact, the built-in cameras of mobile devices are becoming the most common way for visual logging techniques in our daily lives. MCS photo-based frameworks collect photos in a distributed way in which a large number of contributors upload photos whenever and wherever it is suitable. This inevitably leads to evolving picture streams which possibly contain misleading and redundant information that affects the task result. In order to overcome these issues, we develop, in this paper, a solution for selecting highly relevant data from an evolving picture stream and ensuring correct submission. The proposed photo-based MCS framework for event reporting incorporates (i) a deep learning model to eliminate false submissions and ensure photos credibility and (ii) an A-Tree shape data structure model for clustering streaming pictures to reduce information redundancy and provide maximum event coverage. Simulation results indicate that the implemented framework can effectively reduce false submissions and select a subset with high utility coverage with low redundancy ratio from the streaming data.Comment: Published in 2019 IEEE 62nd International Midwest Symposium on Circuits and Systems (MWSCAS

Can docetaxel concomitant administration with bisphosphonates be considered as a risk factor for osteonecrosis of the jaw in metastatic breast cancer patients? A preliminary study.

Osteonecrosis of the jaws (ONJ) is rare complication of bisphosphonates use which was described for the first time by Marx in 2004. Bisphosphonates (BP) are stable derived of inorganic pyrophosphate which had an antiresorbant effect in the bone making them very useful in bone metastasis, especially with the third generation of bisphosphonates. Many risk and trigger factors have been described as predisposing to the development of ONJ. The aim of this work is to show if docetaxel administration can be considered as a predisposing factor to develop ONJ. We report a series of 11 patients treated during 5 years in the maxillofacial surgery department in HU Habib Bourguiba Sfax – Tunisia for ONJ due to BP use for breast cancer bone metastasis. Those patients were divised into two sub-groups: with and without concomitant docetaxel administration. All patients’ data (age and delay of appearance of ONJ, cumulative doses and trigger factors) were collected and analyzed. It was found that patients treated with docetaxel in association to bisphosphonates developed ONJ in earlier age, with a lower cumulative doses of zoledronic acid within a shorter delay period. ONJ occurred in these patients even in the absence of trigger factor and intrinsic risk factors

Gall Bladder Carcinoma: Clinical Presentations and Different Modalities of Treatment

Gallbladder cancer (GBC) is the most common cancer of the biliary tract and has a particularly high incidence in Chile, Japan and northern India. The clinical presentation of GBC is often vague or delayed relative to pathologic progression, contributing to advanced staging and dismal prognosis at the time of diagnosis. In the diagnosis of GBC, differential diagnosis and determination of the local extension of tumor are important. For these purposes, imaging modalities such as endoscopic ultrasonography (EUS), CT, MRI and magnetic resonance cholangiopancreatography (MRCP) are useful. The treatment of localized GBC is based on surgery. Chemotherapy has been used extensively in advanced GBC, and we have gained some experience with gemcitabine-based combination (with cisplatin and oxaliplatin or with capecitabine) regimens

Enhanced ADR for LoRaWAN networks with mobility

International audienceLoRa is becoming an attractive low cost and low power WAN solution for many real-world IoT applications. LoRa has been designed for static end-devices to individually use the optimal configuration through an adaptive data rate mechanism (ADR), thanks to the possibility to choose a set of LoRa physical layer transmission parameters. However a large class of IoT applications (e.g. connected farm) also includes mobile nodes with specific mobility patterns. For those applications, the current ADR control algorithm may not be efficient when the radio channel attenuation rapidly changes because of the node mobility. This paper contributes to enhance the ADR mechanism by taking into account the position of the mobile devices and their trajectories in order to have a dynamic allocation. The Enhanced-ADR (E-ADR) minimizes the transmission time and energy consumption as well as packet loss for mobile devices. The testbed-based experiments show that E-ADR improves the quality of service (QoS) of the overall networks

Dynamic node allocation in Network Virtualization

International audienceNetwork virtualization is a new technology that provides a transparent abstraction of the networking resources. The most important challenge in network virtualization is the allocation of the physical substrate network among the pool of the active virtual networks (VNs). Our work in progress aims at allocating the node resources in a virtualized networking infrastructure. We believe that this allocation should be dynamic to lead to higher performance and better utilization of the physical resources. In this paper, we propose two models for dynamic node allocation for multiple VNs. The first model uses game theory and market-based approach in order to better allocate the physical node. The second one proposes a dynamic weighted round robin (WRR) approach where each VN receives a fraction of the physical node according to an estimation of its current number of waiting packets and its weight. Both models use a distributed approach to minimize the packet delays inside the physical router and to fairly allocate the nodes between different VN

Enhanced Dynamic Duty Cycle in LoRaWAN Network

International audienceLoRa’s long-range and low-power features have made it an attractive candidate for IoT devices in various fields. In this work, we present an enhanced LoRaWAN protocol. LoRaWAN MAC protocol is characterized by the restrictive use of the channel, limited by the regulatory authorities to a 1% duty cycle per cycle (i.e., 36 s per hour) per node. This regulation penalizes the nodes which require a channel access time greater than the limited duty cycle to occasionally transmit a large amount of data such as video surveillance or access control information in applications like smart school surveillance. However, some other nodes like environment sensors sharing a same LoRaWAN server may send very small amounts of information (e.g. temperature, humidity, ...) and under-use the authorized activity time of 1% duty cycle. Hence the idea of implementing an activity time sharing mechanism among nodes that allows devices to borrow additional activity time from a device or set of devices that have completed the transmission of their packets and do not need the remaining time of the corresponding duty cycle. Our work extends and improves the activity time sharing mechanism initially proposed in [1]. Instead of FIFO sharing-time allocation based on a global activity time, which may lead to the starvation of the nodes that are others than that in the head of FIFO line, we propose a new time allocation algorithm based on the classification of the different requests according to their needs in terms of their QoS requirements. It allows to satisfy a larger number of nodes requiring extra time, with less control overheads while ensuring fairness. Our time-sharing algorithm has been implemented and tested on the wasp-mote chip of libelium, showing the performance improvement and its practical usability

A Three-Tiered Architecture for Large-Scale Wireless Hospital Sensor Networks

International audienceThe Utra Wide Band physical layer specified by the IEEE 802.15.4a standard [1] presents numerous advantages comparing with its original IEEE 802.15.4 standard, namely high accuracy positioning ability, high data rate up to 27 mbps, extended communication range, low power consumption and low complexity. Actually, many research and development activities focus on the design of UWB sensor nodes entities. However nodes interactions or network configuration are neglected. For that, we propose in this paper to investigate the use of UWB for large scale Wireless Hospital Sensor Networks (WHSNs) to benefit from the advantages offered by the UWB technology. This evolving networking paradigm promises to revolutionize healthcare by allowing inexpensive, non-invasive, pervasive and ubiquitous, ambulatory health monitoring. We present the design of new system architecture, based on IEEE 802.15.4a compliant sensors, suitable for health monitoring application in high dense hospital environment. The proposed system architecture is intended to support large-scale deployment and to improve the network performance in terms of energy efficiency, real-time guarantees and Quality-of-Service (QoS)