8 research outputs found

    Environmental Parameters Monitoring And Control System In Horticulture Greenhouse Using The Internet Of Things: Case Of IPRC Musanze

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    Efficient management of greenhouse farming is a challenge to ensure high yield production. This is a great challenge to farmers who do not have a reliable mechanism to ensure the optimum environmental conditions for their crops. Farmers are opting to look for solutions from technologies such as Machine to Machine and Internet of Things. This paper proposes a wireless sensor network architecture for real-time greenhouse environmental parameters monitoring to achieve technology- based farming at a low management cost. Uncontrolled temperature, humidity, light intensity and soil moisture content, are among the major parameters that contribute to the deterioration of plants in the green house. The system employs the temperature and Humidity sensor DHT11, a light sensor LDR and soil moisture sensor to detect the environment parameters inside the greenhouse. A low-cost Wi-Fi microchip, with built -in TCP/IP networking software called as ESP8266, has been used to help connect the microntroller with the internet wirelessly. Sensed data is monitored on-site using a Liquid Crystal Display. The ThingSpeak Cloud platform has been used to assure the remote monitoring of the sensed data, and further analytics can be done through it. Actuators namely the solenoid valve, cooling fan, and heating bulb are immediately triggered in case the limit level of the environmental parameters been sensed, has been exceeded. The Global System for Mobile Communication has been used to provide notification to the farmers cell phone farmers in case of critical conditions.  The results of the system are provided in form of waveforms observed through the ThingSpeak for the sensed parameters, others are in form of notification through LCD and GSM, and the actions performed by the solenoid valve, cooling fan and Heating bulb in case the sensed environment data goes beyond the required level

    Efficient access of mobile flows to heterogeneous networks under flash crowds

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    Future wireless networks need to offer orders of magnitude more capacity to address the predicted growth in mobile traffic demand. Operators to enhance the capacity of cellular networks are increasingly using WiFi to offload traffic from their core networks. This paper deals with the efficient and flexible management of a heterogeneous networking environment offering wireless access to multimode terminals. This wireless access is evaluated under disruptive usage scenarios, such as flash crowds, which can mean unwanted severe congestion on a specific operator network whilst the remaining available capacity from other access technologies is not being used. To address these issues, we propose a scalable network assisted distributed solution that is administered by centralized policies, and an embedded reputation system, by which initially selfish operators are encouraged to cooperate under the threat of churn. Our solution after detecting a congested technology, including within its wired backhaul, automatically offloads and balances the flows amongst the access resources from all the existing technologies, following some quality metrics. Our results show that the smart integration of access networks can yield an additional wireless quality for mobile flows up to thirty eight percent beyond that feasible from the best effort standalone operation of each wireless access technology. It is also evidenced that backhaul constraints are conveniently reflected on the way the flow access to wireless media is granted. Finally, we have analyzed the sensitivity of the handover decision algorithm running in each terminal agent to consecutive flash crowds, as well as its centralized feature that controls the connection quality offered by a heterogeneous access infrastructure owned by distinct operators

    Internet of things for monitoring environmental conditions in greenhouses: a case of Kiambu County

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    Efficient management of greenhouse farming is a challenge to ensure high yield production. This is a great challenge to farmers who do not have a reliable mechanism to ensure the optimum environmental conditions for their crops. Farmers are opting to look for solutions from technologies such as Machine to Machine and Internet of Things. Machine to Machine Communication refers to solutions that allow communication between devices of the same type and a specific application through wired or wireless communication networks. Moreover, Internet of Things is a connection of physical things to the internet which makes it possible to access remote data and control the physical world from a distance. These types of solutions allow end-users to capture data about events and transfer it to other devices but they do not allow broad sharing of data or connection of the devices directly to the Internet. In this thesis, the researcher investigated the use of machine to machine communication by having small electronic devices equipped with sensors that when deployed in a farm they can record the environmental conditions and communicates the information to the farmers. Moreover, the different types of crops grown in greenhouses at Kiambu County. Thereafter, the information was analyzed and sent to relevant end users such as the farmer and a metrological department that will enable them to monitor and adapt to the environmental conditions. The research used applied method of research, interviews and questionnaires to gather data. Therefore, an IoT prototype was developed to gather the critical environmental conditions in a greenhouse. The recorded data was transmitted by wireless networks using machine to machine (M2M) technologies from the sensors to the cloud platform, Intel IoT analytics dashboard, for real-time predictive analysis of the environmental parameters. An email notification was sent to alert the farmers when the parameters exceeded the threshold which were preset. This IoT prototype was used in small to large commercial indoor operations as well as small personal gardens

    Collecting sensed data with opportunistic networks: The case of contact information overhead

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    The rising human population in urban environments drives the mission towards smart cities, which envisions a wide deployment of sensors in order to improve the quality of living. In this regard, opportunistic networks (OppNets) present an economical means of collecting delay tolerant data from sensors to their respective gateways for providing various Smart City services. Due to the distributed nature of the network, encounter-based routing protocols achieve acceptable throughput by requiring nodes to exchange and update contact information on an encounter basis. Unfortunately, sufficient insight into the associated overhead is lacking in the literature. Hence, we contribute by modelling contact information overhead and investigating its impact on OppNet routing, particularly in terms of data exchange success and energy consumption on portable handheld devices. Our findings reveal that the expected contact information overhead in Smart City scenarios significantly reduces data exchange success and increases energy consumption on portable handheld devices, thereby threatening the feasibility of the technology. We address this issue by proposing an algorithm that can be incorporated into encounter-based routing protocols to reduce contact information overhead without compromising throughput. Simulation results show that our proposed algorithm reduces the average contact information overhead, increases throughput and reduces average energy consumption

    PDRM : a proactive data replication mechanism to improve content mobility support in NDN using location awareness

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    The problem of handling user mobility has been around since mobile devices became capable of handling multimedia content and is still one of the most relevant challenges in networking. The conventional Internet architecture is inadequate in dealing with an ever-growing number of mobile devices that are both consuming and producing content. Named Data Networking (NDN) is a network architecture that can potentially overcome this mobility challenge. It supports consumer mobility by design but fails to offer the same level of support for content mobility. Content mobility requires guaranteeing that consumers manage to find and retrieve desired content even when the corresponding producer (or primary host) is not available. In this thesis, we propose PDRM, a Proactive and locality-aware Data Replication Mechanism that increases content availability through data redundancy in the context of the NDN architecture. It explores available resources from end-users in the vicinity to improve content availability even in the case of producer mobility. Throughout the thesis, we discuss the design of PDRM, evaluate the impact of the number of available providers in the vicinity and in-network cache capacity on its operation, and compare its performance to Vanilla NDN and two state-of-the-art proposals. The evaluation indicates that PDRM improves content mobility support due to using object popularity information and spare resources in the vicinity to help the proactive replication. Results show that PDRM can reduce the download times up to 53.55%, producer load up to 71.6%, inter-domain traffic up to 46.5%, and generated overhead up to 25% compared to Vanilla NDN and other evaluated mechanisms.O problema de lidar com a mobilidade dos usuários existe desde que os dispositivos móveis se tornaram capazes de lidar com conteúdo multimídia e ainda é um dos desafios mais relevantes na área de redes de computadores. A arquitetura de Internet convencional é inadequada em lidar com um número cada vez maior de dispositivos móveis que estão tanto consumindo quanto produzindo conteúdo. Named Data Networking (NDN) é uma arquitetura de rede que pode potencialmente superar este desafio de mobilidade. Ela suporta a mobilidade do consumidor nativamente, mas não oferece o mesmo nível de suporte para a mobilidade de conteúdo. A mobilidade de conteúdo exige garantir que os consumidores consigam encontrar e recuperar o conteúdo desejado mesmo quando o produtor correspondente (ou o hospedeiro principal) não estiver disponível. Nesta tese, propomos o PDRM (Proactive Data Replication Mechanism), um mecanismo de replicação de dados proativo e consciente de localização, que aumenta a disponibilidade de conteúdo através da redundância de dados no contexto da arquitetura NDN. Ele explora os recursos disponíveis dos usuários finais na vizinhança para melhorar a disponibilidade de conteúdo, mesmo no caso da mobilidade do produtor. Ao longo da tese, discutimos o projeto do PDRM, avaliamos o impacto do número de provedores disponíveis na vizinhança e a capacidade de cache na rede em sua operação e comparamos seu desempenho com NDN padrão e duas propostas do estado-da-arte. A avaliação indica que o PDRM melhora o suporte à mobilidade de conteúdo devido ao uso de informações de popularidade dos objetos e recursos extras na vizinhança para ajudar a replicação pró-ativa. Os resultados mostram que o PDRM pode reduzir os tempos de download até 53,55%, o carregamento do produtor até 71,6%, o tráfego entre domínios até 46,5% e a sobrecarga gerada até 25% em comparação com NDN padrão e os demais mecanismos avaliados

    Information-centric communication in mobile and wireless networks

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    Information-centric networking (ICN) is a new communication paradigm that has been proposed to cope with drawbacks of host-based communication protocols, namely scalability and security. In this thesis, we base our work on Named Data Networking (NDN), which is a popular ICN architecture, and investigate NDN in the context of wireless and mobile ad hoc networks. In a first part, we focus on NDN efficiency (and potential improvements) in wireless environments by investigating NDN in wireless one-hop communication, i.e., without any routing protocols. A basic requirement to initiate informationcentric communication is the knowledge of existing and available content names. Therefore, we develop three opportunistic content discovery algorithms and evaluate them in diverse scenarios for different node densities and content distributions. After content names are known, requesters can retrieve content opportunistically from any neighbor node that provides the content. However, in case of short contact times to content sources, content retrieval may be disrupted. Therefore, we develop a requester application that keeps meta information of disrupted content retrievals and enables resume operations when a new content source has been found. Besides message efficiency, we also evaluate power consumption of information-centric broadcast and unicast communication. Based on our findings, we develop two mechanisms to increase efficiency of information-centric wireless one-hop communication. The first approach called Dynamic Unicast (DU) avoids broadcast communication whenever possible since broadcast transmissions result in more duplicate Data transmissions, lower data rates and higher energy consumption on mobile nodes, which are not interested in overheard Data, compared to unicast communication. Hence, DU uses broadcast communication only until a content source has been found and then retrieves content directly via unicast from the same source. The second approach called RC-NDN targets efficiency of wireless broadcast communication by reducing the number of duplicate Data transmissions. In particular, RC-NDN is a Data encoding scheme for content sources that increases diversity in wireless broadcast transmissions such that multiple concurrent requesters can profit from each others’ (overheard) message transmissions. If requesters and content sources are not in one-hop distance to each other, requests need to be forwarded via multi-hop routing. Therefore, in a second part of this thesis, we investigate information-centric wireless multi-hop communication. First, we consider multi-hop broadcast communication in the context of rather static community networks. We introduce the concept of preferred forwarders, which relay Interest messages slightly faster than non-preferred forwarders to reduce redundant duplicate message transmissions. While this approach works well in static networks, the performance may degrade in mobile networks if preferred forwarders may regularly move away. Thus, to enable routing in mobile ad hoc networks, we extend DU for multi-hop communication. Compared to one-hop communication, multi-hop DU requires efficient path update mechanisms (since multi-hop paths may expire quickly) and new forwarding strategies to maintain NDN benefits (request aggregation and caching) such that only a few messages need to be transmitted over the entire end-to-end path even in case of multiple concurrent requesters. To perform quick retransmission in case of collisions or other transmission errors, we implement and evaluate retransmission timers from related work and compare them to CCNTimer, which is a new algorithm that enables shorter content retrieval times in information-centric wireless multi-hop communication. Yet, in case of intermittent connectivity between requesters and content sources, multi-hop routing protocols may not work because they require continuous end-to-end paths. Therefore, we present agent-based content retrieval (ACR) for delay-tolerant networks. In ACR, requester nodes can delegate content retrieval to mobile agent nodes, which move closer to content sources, can retrieve content and return it to requesters. Thus, ACR exploits the mobility of agent nodes to retrieve content from remote locations. To enable delay-tolerant communication via agents, retrieved content needs to be stored persistently such that requesters can verify its authenticity via original publisher signatures. To achieve this, we develop a persistent caching concept that maintains received popular content in repositories and deletes unpopular content if free space is required. Since our persistent caching concept can complement regular short-term caching in the content store, it can also be used for network caching to store popular delay-tolerant content at edge routers (to reduce network traffic and improve network performance) while real-time traffic can still be maintained and served from the content store
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