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    Correction - Wireless sensor networks

    << Forum anglais: Questions sur l'anglais || En bas

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    Correction - Wireless sensor networks
    Message de david81 posté le 08-02-2010 à 17:33:56 (S | E | F)

    Bonjour à tous,

    J'ai une petite introduction à écrire en anglais et j'aurais aimé avoir votre avis sur la sensibilité des phrases utilisés ainsi que sur le respect de l'anglais.

    In a wireless sensor network (WSN), sensors are powered by limited batteries. In most applications, sensors are required to be operating in order of months to years. Generally, these batteries cannot be replaced because sensors are deployed in specific areas with no maintenance. Hence, sensors can only transmit a finite number of packets before lacking energy. A common mechanism to reduce the energy consumption is to turn the transceiver of sensor nodes into a low power sleep state when it is not used.

    The advances in technologies have enabled the deployment of large-scale wireless sensor networks where sensors send collected data (temperature, humidity…) to one or more sink nodes. WSNs are multi-hop networks due to the deployment of sensors on a large coverage area. A routing protocol is required to find a route between a sensor and the sink.

    WSNs are used in a wide range of applications as military, health, vehicular. Military applications may range from detecting enemy position on the battlefield. Vehicular applications may range from maintaining the cold chain. Furthermore, this type of network is very useful to collect data in hostile environment such as volcano, forest, sea.

    Cross-layer design is a new concept. This new technique aims to achieve gains in overall system performance in wireless networks. In a cross-layer design, the different layers of the conventional OSI model interact with each other, irrespective of their positions in the model to achieve a specific result. Due to the lack of memory and energy, it becomes difficult to use the traditional layer model in wireless sensor networks [7].

    Cross-layer techniques improve energy conservation in wireless sensor networks [6]. Hence, lot of cross-layer routing protocols have been proposed to reduce the energy consumption in wireless sensor networks. These routing protocols are some efficient solutions in the energy conservation. They use MAC layer information such as joint scheduling, power control, sleep state of sensor nodes, to control the energy consumption.

    To date, much of the work on WSNs has focused on the energy minimization problem, taking into consideration the individual sensor node performance, i.e., finding methods that allow each sensor node to consume the minimum amount of energy subject to a given traffic load. However, there has been little focus on a fairness access to the medium. In radio communication, a receiver is able to decode a packet correctly if the difference in signal strength of collided packets (i.e., the capture effect) is above a threshold. Other packets cause some noise. In wireless sensor networks, nodes are at different distances of the sink. In a free space propagation model, the signal attenuation is related with the distance of propagation. Due to the capture effect, nodes close to the sink send more packets than far nodes.


    Merci d'avance.

    Amicalement

    David


    Réponse: Correction - Wireless sensor networks de robertbrou, postée le 08-02-2010 à 19:17:25 (S | E)
    Bonjour,

    Voici mes suggestions. Dans l'ensemble c'est bien compréhensible.

    In a wireless sensor network (WSN), sensors are powered by limited batteries (have limited battery power?). In most applications, sensors are required to be operating in the order of months to years. Generally, these batteries cannot be replaced because sensors are deployed in specific areas with no maintenance (add text that explains that it is difficult/impossible/not capable). Hence, sensors can only transmit a finite number of packets before lacking (I would use lose here) energy. A common mechanism to reduce the energy consumption is to turn the transceiver of sensor nodes into a low power sleep state when it is not being used.

    The advances in technologies have enabled the deployment of large-scale wireless sensor networks where sensors send collected data (temperature, humidity…) to one or more sink nodes. WSNs are multi-hop networks due to the deployment of sensors on a large coverage area. A routing protocol is required to find a route between a sensor and the sink.

    WSNs are used in a wide range of applications as military, health, vehicular. Military applications may range from detecting enemy position on the battlefield. Vehicular applications may range from maintaining the cold chain. Furthermore, this type of network is very useful to collect data in hostile environments such as volcanoes, forests, and seas.

    Cross-layer design is a new concept. This new technique aims to achieve gains in overall system performance in wireless networks. In a cross-layer design, the different layers of the conventional OSI model interact with each other, irrespective of their positions in the model to achieve a specific result. Due to the lack of memory and energy, it becomes difficult to use the traditional layer model in wireless sensor networks [7].

    Cross-layer techniques improve energy conservation in wireless sensor networks [6]. Hence, lot of (use synonym) cross-layer routing protocols have been proposed to reduce the energy consumption in wireless sensor networks. These routing protocols are some efficient solutions in the energy conservation. They use MAC layer information such as joint scheduling, power control, and sleep state of sensor nodes, to control the energy consumption.

    To date, much of the work on WSNs has focused on the energy minimization problem, taking into consideration the individual sensor node performance, i.e., (use synonym) finding methods that allow each sensor node to consume the minimum amount of energy subject to a given traffic load. However, there has been little focus on a fairness access to the medium. In radio communication, a receiver is able to decode a packet correctly if the difference in signal strength of collided packets (i.e., the capture effect) is above a threshold. Other packets cause some noise. In wireless sensor networks, nodes are at different distances of (de=of,from) the sink. In a free space propagation model, the signal attenuation is related with (look up related) the distance of the propagation. Due to the capture effect, nodes close to the sink send more packets than far nodes.

    Hope this helps!


    Réponse: Correction - Wireless sensor networks de david81, postée le 08-02-2010 à 20:01:57 (S | E)
    Bonjour,

    Merci beaucoup pour ton aide, ça m'aide énormément à parfaire mon anglais J'ai apporté des modification aux paragraphes où il y avait du rose, donc des éléments à reprendre.

    In a wireless sensor network (WSN), sensors have limited battery power. In most applications, sensors are required to be operating in the order of months to years. Generally, these batteries cannot be replaced because sensors are deployed in specific areas with no maintenance (the access at the sensors is difficult and may be expensive). Hence, sensors can only transmit a finite number of packets before losing energy. A common mechanism to reduce the energy consumption is to turn the transceiver of sensor nodes into a low power sleep state when it is not being used.

    Cross-layer techniques improve energy conservation in wireless sensor networks [6]. Hence, most cross-layer routing protocols have been proposed to reduce energy consumption in wireless sensor networks. These routing protocols are efficient solutions in the energy conservation. They use MAC layer information such as joint scheduling, power control, and sleep state of sensor nodes, to control energy consumption.

    To date, much of the work on WSNs has focused on the energy minimization problem, taking into consideration the individual sensor node performance, in other words, finding methods that allow each sensor node to consume the minimum amount of energy subject to a given traffic load. However, there has been little focus on a fairness access to the medium. In radio communication, a receiver is able to decode a packet correctly if the difference in signal strength of collided packets (i.e., the capture effect) is above a threshold. Other packets cause noise. In wireless sensor networks, nodes are at different distances from the sink. In a free space propagation model, signal attenuation looks up related to the distance of the propagation. Due to the capture effect, nodes close to the sink send more packets than far nodes.

    Encore merci,

    David



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