Distributed Region-Based Monitoring in Low-Power Listening Wireless Sensor Networks

Advancement in IoT technology and the concept of Information-Centric Networking lead to less importance of node individuality since several nodes can work interchangeably. Multiple sensor nodes can be grouped into a region and monitored as one instance to guarantee sufficient coverage over the region. Therefore, a single node fault often does not need to be reported unless it is the last node in the region. In addition, there are occasions where a central monitor station cannot rely on continuous data delivery from nodes or regions to decide whether they are still alive, such as situations when nodes are deployed to detect rare events. Moreover, low-power listening MAC protocols, which significantly help reducing power consumption while nodes are mostly idle, put a lot more work on the transmission process. In such situations it is desirable to minimize status reports to the central monitor station. A distributed region-based monitoring scheme, or DRMON, is then proposed to facilitate this circumstance. This approach designates a representative to each region so that it can be used as an indicator of the region's status with a mechanism to re-elect a new representative until all nodes in the respective region are dead, implying region inactiveness. We evaluate the suitability of DRMON over various scenarios in two aspects: centralized vs. distributed monitoring schemes and individual-based vs. region-based monitoring schemes. Simulation results indicate that region-based schemes outperform the individual schemes in terms of power consumption and scalability when the number of regions is low. The distributed schemes also yield better efficiency in terms of message overhead and load distribution. In addition, detection accuracy of all schemes is not significantly different and fault detection delay is guaranteed. This outcome suggests that in the case where existence of individual node is out of concern, distributed region-based fault monitoring scheme could be employed to reduce energy usage and lower message overhead while retaining the detection accuracy.

Achievement of a Radio Monitor Station Management Data Framework

A radio monitor station (RMS) gathers the radio flag data of a substantial scope of recurrence for the administration. The framework is completely fledged with essential and propelled functionalities and now in charge of a common of radio transmission capacity use. To address the difficulties of huge dynamic information, we have built up an area particular management data framework (MDF) for the radio monitor stations. The framework outline and usage are depicted in the paper. A calculation is furnished to work with the radio transmission models for count of the radio flag scopeday by day RMS management in practice.

PM2.5 personal exposure and sources of population living near 2 environment monitoring stations in Ho Chi Minh city

Air pollution epidemiology studies have found statistically significant associations between particulate matter (PM) concentrations and morbidity, mortality. 24-h personal PM 2,5 exposures were sampled by PEM 2,5 (SKC) with flowrate 4 l/minute on teflon filter (Pall). 64 households in Binh Thanh and district 2 (HCM city) were monitored from 7/2007 to 3/2008, repeated 9 times for each household. Elements in particle were analysed by INAA. Software PMF 5,0 (EPA) was used to detemine PM2,5 sources. PM2,5 was also monitored at 2 fixed-site monitor stations, D2 and zoo, during sampled time with the same 24H Personal PM 2,5 method. Medium PM2,5 concentration at fixed-site monitor station was 48,99 ± 21,68 μg/m3 (median: 46,46 μg/m3), lower than the ambient standard limit. 24-h personal PM 2,5 exposure was là 64,28 ± 33,18 μg/m3 (median: 58,17 μg/m3), higher than the ambient standard limit (p<0,05). PM2,5 sources were from dust (16,03%), traffic (17,72%), industrial (30,48%), indoor activity (21,03%) and marine (14,74%).

Dual-Channel Measurement System for Real-Time Ethernet

Real-time Ethernet (RTE) is widely used in industrial automation and high performance motion control field. Its minimum cycle time is down to less than 100μs and cycle jitter is less than 1μs, making many existing network and protocol analyzers cant meet the requirements of time accuracy in measurement system for RTE. In this paper, a low-cost and open measurement system is proposed to analyze the time characteristics (cycle time, cycle jitter, end-to-end delay, etc.) and protocol (Ethernet type, length, detailed info, etc.) of real-time Ethernet. The measurement system is consisting of a FPGA-based hardware device and a PC-based monitor station. The hardware device has dual channels that allow detecting two nodes data frame simultaneously. Ethernet data frames through channels are transmitted immediately; at the same time, all data frames will be duplicated and sent to the monitor station with precise timestamp for frame analysis. A prototype of measurement system has been realized to verify feasibility and performance. Result of the experiment shows that the maximal delay time brought in by measuring device is only 120ns and the accuracy of time stamp is down to 5ns; the parser is created in the monitor PC for analysis the time characteristics and protocols of real-time Ethernet.

Hardware Design of Code Transmitter and Monitor Station

The wireless transceiver and monitor station own the same structure. The wireless transceiver is mainly composed of high-powered, embed wireless module PTR8000, which implants complete communication protocol and CRC. PTR8000 communicates with MPU fleetly exactly by serial port.