The master thesis is concerned with problem of localization of nodes in wireless sensor network WSN implemented by ZigBee technology. The thesis provide description of ZigBee architecture involving signal description. The method of evaluating coordinates basically do not depend on used measuring methods. The method  of fingerprinting is included in separated category based on only statistical processing of RSSI data. Determination of coordinates of mobile node always needs finding out range, signal time of arrival (ToA) or angle of arrival (AoA) in respect to anchors node given dimension magnitude. The author found out three possible solutions for range measuring and one solution for angle of arrival measuring useable in context of ZigBee wireless sensor network. Finally the author discuss possibilities and constraints of ZigBee network with used measuring type.

Wireless Sensor Network (WSN) is an emerging multi-hop wireless network technology, and the greenhouse network monitoring system is one of the key applications of WSNs in which various parameters such as temperature, humidity, pressure and power can be monitored. Here, we aim to study the performance of a simulation-based greenhouse monitoring system. To design the greenhouse monitoring system based on WSN, we have used ZigBee-based devices (end devices, routers, coordinators, and actuators. Our proposed greenhouse monitoring network has been designed and simulated using the network simulator OPNET Modeller.The investigation is split into two; first, the aim is to find the optimal Transmit (Tx) power set out at sensor nodes and second, the focus is on studying how increasing the number of sensor nodes in the same greenhouse network will affect the overall network performance. ZigBee-based greenhouses corresponded to 4 network scenarios and are simulated using OPNET Modeller in which 22 different transmit (Tx) power (22 cases) in Scenario 1 is simulated, scenario 2, 3 and 4 estimated to 63, 126, 189 number of sensor nodes respectively. Investigating the performance of the greenhouse monitoring network performance metrics such as network load, throughput, packets sent/received and packets loss are considered to be evaluated under varied transmit (Tx) power and increasing number of sensor nodes. Out of the comprehensive studies concerning simulation results for 22 different transmit (Tx) power cases underlying the greenhouse monitoring network (Scenario1), it is found that packets sent/received and packets loss perform the best with the transmitted (Tx) power falling in a range of 0.9 mWatt to 1.0 mWatt while packet sent/received and packet loss are found to perform moderately with the transmitted (Tx) power values that lie in a range of 0.05 mWatt to 0.8 mWatt. Less than 0.05 mWatt and greater than 0.01 microWatt Tx power experience, the worst performance in terms of particularly packet dropped case. For instance, in the case of the packet dropped (not joined packet, i.e., generated at the application layer but not able to join the network due to lack of Tx power), with a Tx power of 0.01 mWatt, 384 packets dropped with a Tx power of 0.02 and 0.03 mWatt, 366 packets dropped, and with a Tx power of 0.04 and 0.05, 336 packet dropped.While increasing the number of sensor nodes, as in scenario 2, 3 and 4, dealing with sensor nodes 63, 126 and 189 correspondingly, the MAC load, MAC throughput, packet sent/received in scenario 2 are found to perform better than that of scenario 3 and scenario 4, while packet loss in scenarios 2, 3 and 4 appeared to be 15%, 12% and 83% correspondingly.

Les besoins de nouveaux services dans les rames ferroviaires ( le comptage, l’efficience énergétique, le confort et la sécurité des passagers etc.), risquent de saturer à terme les systèmes de communication filaires mis en place il y a une vingtaine d’années. Les réseaux de capteurs sans fil, par leurs avantages (déploiement facile, capacité à s’adapter à plusieurs types d’environnements, faible consommation d’énergie), ouvrent de nombreuses perspectives pour les systèmes de gestion énergétique. Le but de ce travail de thèse est d’étudier et mettre en oeuvre un réseau de capteurs sans fil à l’intérieur des trains pour l’efficience énergétique. Ainsi, quelques protocoles de communication dédiés à la gestion énergétique ont été présentés puis une étude comparative des différents réseaux de communication sans fil réalisée. Cette étude comparative a permis de faire le choix du réseau ZigBee comme étant le plus adéquat pour la plateforme. L’architecture hybride proposée permet l’utilisation du réseau IP existant comme colonne vertébrale de l’ensemble des réseaux ZigBee. Afin de tenir compte de l’effet de l’environnement ferroviaire dans la planification et le déploiement du réseau, une étude du canal de propagation, basée sur des mesures réalisées dans un métro et un wagon de RER a été menée. L’impact de la coexistence entre le ZigBee et le WiFi et de la présence humaine sur la communication du réseau sans fil a été démontré. Le prototype d’une plateforme basée sur le réseau ZigBee allant de la collecte des données à l’affichage des informations a été réalisé et testé. / The need of new services in railway trains (services for metering, energy efficiency, the comfort and safety of users etc.) may eventually saturate the wired communication systems installed since twenty years ago years. The several advantages of wireless sensor networks (easy deployment, ability to adapt on different environments and low energy consumption) offer many possibilities for energy management systems. The aim of this thesis is to study and implement a wireless network sensors inside trains for energy efficiency. Thus, some communication protocols dedicated to energy management were presented and then a comparative study of the various wireless communication networks carried out. This comparative study shows that the ZigBee network is the most suitable for the platform. The proposed hybrid architecture allows the use of the existing IP network as the backbone of all ZigBee networks. In order to take into account the effect of the railway environment in the planning and deployment of the network, a study of the propagation channel was carried out, based on measurements realized in a subway and a RER car. The impact of the coexistence between ZigBee and WiFi and of the human presence on wireless communication have been demonstrated. The prototype of a platform based on the ZigBee network, allows data collection, informations traitement and monitoring, was carried out.