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  • 1.
    Bagula, Antoine
    et al.
    University of Cape Town.
    Inggs, Gordon
    University of Cape Town.
    Scott, Simon
    University of Cape Town.
    Zennaro, Marco
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    On the Relevance of Using Open Wireless Sensor Networks in Environment Monitoring2009Inngår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 9, nr 6, s. 4845-4868Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper revisits the problem of the readiness for field deployments of wireless sensor networks by assessing the relevance of using Open Hardware and Software motes for environment monitoring. We propose a new prototype wireless sensor network that fine-tunes SquidBee motes to improve the life-time and sensing performance of an environment monitoring system that measures temperature, humidity and luminosity. Building upon two outdoor sensing scenarios, we evaluate the performance of the newly proposed energy-aware prototype solution in terms of link quality when expressed by the Received Signal Strength, Packet Loss and the battery lifetime. The experimental results reveal the relevance of using the Open Hardware and Software motes when setting up outdoor wireless sensor networks.

  • 2.
    Flickenger, Rob
    et al.
    Hacker Friendly LLC.
    Okay, Steve
    Inveneo.
    Pietrosemoli, Ermanno
    EsLaRed-ULA.
    Zennaro, Marco
    ICTP.
    Fonda, Carlo
    ICTP.
    Very long distance Wi-Fi networks2008Inngår i: Proceedings of the ACM SIGCOMM 2008 Conference on Computer Communications -2nd ACM SIGCOMM Workshop on Networked Systems for Developing Regions, NSDR'08, 2008, s. 1-5Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    802.11 Wi-Fi technology is commonly used for creating wireless networks with a range of about one hundred meters. With careful planning and proper antennas, this same equipment can be used to make point-to-point links of hundreds of kilometers. This paper presents a successful 279 km link made by wireless experts in Venezuela, and a permanent 133 km test network in northern Italy for ongoing research.

  • 3.
    Ntareme, Hervé
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Telekommunikationssystem, TSLab (stängd 2012-01-01).
    Zennaro, Marco
    ICTP – International Centre for Theoretical Physics, Trieste, Italy.
    Pehrson, Björn
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Telekommunikationssystem, TSLab (stängd 2012-01-01).
    Delay Tolerant Network on smartphones: Applications for communication challenged areas2011Inngår i: ExtremeCom '11 Proceedings of the 3rd Extreme Conference on Communication: The Amazon Expedition, ACM Press, 2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper discusses the Delay Tolerant Network (DTN) serviceand protocol stack and presents an implementation of it on theAndroid platform that is called "Bytewalla". It allows the use ofAndroid phones for the physical transport of data betweennetwork nodes in areas where there are no other links available, orwhere existing links need to be avoided for security reasons or incase the Internet is shut down by a government authority like ithappened in some Arab countries during the spring of 2011.The implementation of a store and forward messaging applicationand a Sentinel Surveillance health-care application (SSA) thatruns on top of Bytewalla are presented together with a few usagescenarios. Our conclusion is that the integration of DTN links inthe general IP-network architecture on mobile phone platform isfeasible and will make it easier to integrate DTN applications intocommunication-challenged areas. To our knowledge ourimplementation of the bundle protocol is the first on the Androidplatform.

  • 4.
    Zennaro, Marco
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Wireless Sensor Networks for Development: Potentials and Open Issues2010Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Wireless Sensor Networks (WSNs) provide a way to bridge the gap between the physical and the virtual worlds. They promise unprecedented abilities to observe and understand large-scale, real-world phenomena at a fine spatial-temporal resolution. Their application in Developing Countries is evenmore interesting: they can help solve problems that affect communities. The number of potential applications in such an environment is huge: water monitoringand crop modeling are just two examples.

    This thesis will analyze the potential of WSNs in Developing Countries, and tackle three of the main problems that their deployment poses:

    1. Power. Power consumption is an important issue in deployments. For WSN nodes this is a well-addressed issue. Most commercial solutions today assume that WSN gateways (the devices that provide the interface between the nodes and the network infrastructure) will encounter ideal scenarios in terms of power when deployed. In a Developing World scenario, the gateway must operate with bounded energy supplies. The gateway should have sufficient stored power to save sensed data with high probabilities of service interruptions due to power loss.

    2. Connectivity. Network connectivity in many Developing Countries is unreliable. Data gathered by the sensor nodes (motes) must therefore be stored safely in the gateway and transferred when a network connection is available. WSN deployments can encounter different network topologies such as wired, wireless and mesh, and should be flexible enough to interact with each of them. A two layer architecture with long wireless links above a wireless sensor network is a practical alternative for providing connectivity in the access network.

    3. Quality of WSN links. To implement reliable and robust sensor networks, we need to understand the variation of link quality and battery behavior in a real world environment. Low-power transmitters have a limited range, and it is important to understand communication patterns. Energy is the scarcest resource of WSN motes, and it determines the lifetime of WSNs. Motes are meant to be deployed in various environments, including remote and hostile regions; consequently, they must use little power and one need to make sure that all batteries last the same amount of time. Also, battery level has an impact on routing.

    There is still research to be carried out to make WSNs suitable for deploymen tin Developing Regions. Following the most recent developments of sensor networks, this thesis discusses what ICT4D researchers could do to accelerate the dissemination of this new technology and proposes prototype solutions for some of the three problems mentioned above.

    These include:

    Efficient link quality models. Link quality models are important tools upon which the deployment of wireless sensor networks depends. They allow the selection of efficient working parameters that enable the information collected by sensor networks to be routed efficiently from WSN nodes to a sensor base station. Using two testbed WSNs based on two different technologies, we analyzed spatial and temporal behavior of link quality and derived good working parameters for sensor network deployments. These parameters have been used in related works to design new routing protocols for sensor networks.

    Robust and flexible gateways. Building upon the assumption that a WSN gateway to be deployed in developing regions should be designed at low cost with battery backup to maintain a continuous supply of electric power in absence of power grid, we proposed in this thesis two low-cost solutions that 1) meet low-power consumption and high storage capabilities constraints 2) are based on web technologies and (3) allow long range deployment for information dissemination. These solutions are developed around two smart board systems.

    Long wireless links. Besides power energy limitations, limited range is one of the main factors which has delayed large scale deployments of wireless sensor networks. Building upon the assumption that next generation sensor networks will be employed in multilayer network environments with a WiFi gateway network layered above islands of sensor networks, we presented the deployment of several long wireless links. These prototypes revealed that long distance links can be a practical, inexpensive alternative for connecting wireless sensor networks while providing access to Internet in Developing Countries.

    Water quality management. We developed a water quality monitoring system to de deployed in Malawi. Water quality measurementadds another dimension to the issue of power consumption of the WSN system since one has to take into account the contribution of the energy consumed by the water quality sensors in the overall energy consumption of the water monitoring system. As low-power sensors for water quality are not yet commercially available, we proposed an energy consumption minimization strategy where a wake-up mechanism that triggers sleeping/wake-up modes is used to reduce energy consumption.

  • 5.
    Zennaro, Marco
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Telekommunikationssystem, TSLab (stängd 2012-01-01). Abdus Salam International Centre for Theoretical Physics, Trieste, Italy .
    Bagula, A.
    Gascon, D.
    Noveleta, A. B.
    Long distance wireless sensor networks: Simulation vs reality2010Inngår i: Proceedings of the 4th ACM Workshop on Networked Systems for Developing Regions, NSDR '10, 2010, s. 12-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Wireless sensor networks allow unprecedented abilities to observe and understand large-scale, real-world phenomena at a fine spatial-temporal resolution. Their application in Developing Countries is even more interesting: they can help solve problems that affect communities. One of the limitations of current wireless sensors is the communication range, with most devices having 100 meters as maximum limit. In contrast, many applications require long-range wireless sensor network where nodes are separated by large distances, giving the advantage of being able to monitor a vast geographic area. In this paper we will present the results of simulations and of experiments carried out using off-the-shelf equipment over distances ranging from 300m to 12km. The results show that long distance wireless sensor networks (LDWSN) are possible and that the quality of these links is high.

  • 6.
    Zennaro, Marco
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Bagula, Antoine B.
    Design of a flexible and robust gateway to collect sensor data in intermittent power environments2010Inngår i: INT J SENS NETW, ISSN 1748-1279, Vol. 8, nr 3-4, s. 172-181Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The development of a Wireless Sensor Network (WSN) gateway is challenging for sites where limited infrastructures lead to frequent power shortages and network unreliability. In this paper, we present a low-power, low-cost 802.15.4 and 802.11 compatible solution which uses open source software to meet local conditions. Using the SunSPOT motes on a system which is mostly platform independent, our system is based on the Fox embedded Linux board and equipped with a USB flash drive and a USB WiFi adapter. The system can be solar powered, and the results of a solar system design are presented. All the hardware components are available off-the-shelf and are easy to assemble. We conclude that our system is preferred for applications in remote areas, where a stable power supply and a reliable network infrastructure are lacking. Furthermore, it can be used to extend the range of WSNs by layering a network of long-range motes above islands of low-range motes.

  • 7.
    Zennaro, Marco
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Bagula, Antoine
    Gascon, David
    Bielsa Noveleta, Alberto
    Planning and Deploying Long Distance Wireless Sensor Networks: The Integration of Simulation and Experimentation2010Inngår i: 9th International Conference on Ad-Hoc Networks and Wireless Univ Alberta, Edmonton, CANADA, AUG 20-22, 2010, 2010, Vol. 6288, s. 191-204Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Wireless sensor networks allow unprecedented abilities to observe and understand large-scale, real-world phenomena at a fine spatial-temporal resolution. Their application in Developing Countries is even more interesting: they can help solve problems that affect communities. One of the limitations of current wireless sensors is the communication range, with most devices having 100 meters as maximum range. In contrast, many applications require long-range wireless sensor network where nodes are separated by large distances, giving the advantage of being able to monitor a large geographic area. In this paper we will present the results of an integrated approach combining a planning step using simulations and an experimental step carried out using off-the-shelf equipment over distances ranging from 600m to 12km. The results reveal that the simulation results agree with experimentation and show that long distance wireless sensor networks (LDWSN) are possible and that the quality of these links is high. Finally, we discuss the relative efficiency of our solution in terms of range compared to other wireless sensor networks.

  • 8.
    Zennaro, Marco
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Bagula, Antoine
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Ntareme, Hervé
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Inggs, Gordon
    Scott, Simon
    On the relevance of open wireless sensors for NGN2009Inngår i: International Telecommunication Union - Proceedings of the 2009 ITU-T Kaleidoscope Academic Conference: Innovations for Digital Inclusion, K-IDI 2009, IEEE conference proceedings, 2009, s. 193-200Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Open Wireless Sensors are based on the Open Source Software and Open Source Hardware paradigms. The code used to program them and the information about the hardware design are freely released. We present the main characteristics of Open Wireless Sensor Networks (OWSNs) and report on two examples with the experimental results revealing the performance of OWSNs in terms of link quality and battery life. We demonstrate the relevance of using OWSNs in Next Generation Networks by showing the advantages of the Open Source model when applied to Wireless Sensor networks in terms of cost, personalisation and independence from a single entity as compared to proprietary solutions.

  • 9.
    Zennaro, Marco
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Bagula, Antonie
    University of Cape Town.
    Design of a flexible and reliable gateway to collect sensor data in intermittent power environments2009Inngår i: Proceedings of 18th International Conference on Computer Communications and Networks, 2009Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The development of a wireless sensor network (WSN) gateway is challenging for sites where limited infrastructures lead to frequent power shortages and and network unreliability. In this paper we presents a low-power, low-cost, 802.15.4 and 802.11 compatible solution which uses open source software to meet local conditions. Using the SunSPOT motes on a system which is mostly platform independent, our system is based on the Fox embedded Linux board and equipped with a USB flash drive and a USB WiFi adapter. The system can be solarpowered, and the results of a solar system design are presented. All the hardware components are available off-the-shelf and are easy to assemble. We conclude that our system is preferred for applications in remote areas, where a stable power supply and a reliable network infrastructure are lacking. Furthermore, it can be used to extend the range of wireless sensor networks by layering a network of long range motes above islands of low range motes.

  • 10.
    Zennaro, Marco
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Floros, Athanasios
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Dogan, Gokhan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Sun, Tao
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Cao, Zhichao
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Huang, Chen
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Bahader, Manzoor
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Ntareme, Hervé
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Bagula, Antoine B.
    On the design of a Water Quality Wireless Sensor Network (WQWSN): an Application to Water Quality Monitoring in Malawi2009Inngår i: 2009 INTERNATIONAL CONFERENCE ON PARALLEL PROCESSING WORKSHOPS (ICPPW 2009) / [ed] Barolli L; Feng WC, NEW YORK: IEEE , 2009, s. 330-336Konferansepaper (Fagfellevurdert)
    Abstract [en]

    More than one billion people lack access to safe drinking water in the world. Providing a way to measure automatically water quality will help tackle this problem. This paper presents the design of a water quality measuring system and proposes a prototype implementation of a water quality wireless sensor network (WQWSN) as a solution to this challenging problem. When applied to developing countries, the design and implementation of such a system must take into consideration the difficult environment in which it will operate. An application to water quality measurement in Malawi reveals the relevance of using our novel solution to mitigate two challenging issues: energy consumption of the system and the inter-networking problem.

  • 11. Zennaro, Marco
    et al.
    Fonda, Carlo
    Pietrosemoli, Ermanno
    Muyepa, A.
    Okay, Steve
    Flickenger, Rob
    Radicella, S.M.
    On a long wireless link for rural telemedicine in Malawi2008Inngår i: 6th International Conference on Open AccessLilongwe, Malawi, 2008, 2008Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we describe the process that brought us to setup a 162 km wireless link in Malawi: the first experiments in Venezuela and Italy, the equipment selection and the link deployment in August 2008. The network connects the University of Malawi College of Medicine in Blantyre with with the Mangochi Hospital as well as hospitals and research institutions in the cities of Blantyre, Zomba and Mangochi. We show that long-distance Wi-Fi links can be a practical, inexpensive alternative for providing network connectivity and access to the Internet in Developing Countries.

  • 12.
    Zennaro, Marco
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Ntareme, Hervé
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Bagula, Antoine
    University of Cape Town.
    Experimental evaluation of temporal and energy characteristics of an outdoor sensor network2008Inngår i: Proceedings of the International Conference on Mobile Technology, Applications, and Systems, 2008Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper revisits the link quality issue in Wireless Sensor Networks (WSN) by studying the temporal and energy characteristics of a 2, 4Ghz sensor network in an outdoor environment. Using different values of output power and sampling period, we analyze battery behavior in motes placed at different distances and show that farther motes have a shorter battery life. Our experimental results suggest that when deployed in real world deployments, the sampling periods of sensor networks be adjusted according to distance to normalize battery lifetime and a more accurate energy-aware routing protocol be developed.

  • 13.
    Zennaro, Marco
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Ntareme, Hervé
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Telekommunikationssystem, TSLab.
    Bagula, Antoine
    University of Cape Town.
    On the design of a flexible gateway for Wireless Sensor Networks2008Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The development of a Wireless Sensor Network (WSN) gateway is challenging for countries where limited infrastructures lead to frequent power shortages and network unreliability. In this paper we describe the design of a flexible gateway that collects data from WSN, stores them in a database and makes them available via wireless links. In the design of such device, low power, low-cost and flexibility must be taken into account. Our prototype is flexible as it can work as WiFi client, serve as WiFi access point and can connect to OLSR mesh networks. Based on low-cost hardware and on opensource software, it is suitable for being used in challenging environments.

1 - 13 of 13
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