Designing a maintenance free multi-channel wireless sensor network protocol

Wireless sensors are low powered device that is scattered to monitor its surroundings. These energy-constrained devices are usually constructed in a hierarchical structured manner where after sometime some of the nodes may deplete energy resulting disruption of the routing topology in a wireless sensor network. A faulty parent node may cause the reconstruction of the network’s routing topology if a maintenance solution is not provided to the protocol. Thus this study focuses on the maintenance free environment for a multi-channel wireless sensor network. A tree-based solution is proposed for the multi-channel protocol and a route diversion is proposed for the maintenance solution. The multi-channel characteristics is used as a tool to determine the route diversion of the children node. A simulation is built to compare the proposed protocol with existing tree-based multi-channel protocol. The result of the proposed protocol shows an improvement to the packet delivery rate by 15%

HMC-MAC : un protocole MAC hybride et multi-canal pour les réseaux de capteurs sans fil

The use of multi-channel significantly improves the overall network performance of wireless sensor networks (WSNs) by allowing parallel transmissions over multiple channels. However, the design of a multi-channel MAC protocol in a multi-hop network requires an efficient channel allocation method that allows the coordination between the nodes in order to share available channels. In this thesis, we focus on the conception of a multi-channel MAC protocol that meets the requirements of high data collection applications in a multi-hop network. In order to achieve this goal, we first present the main techniques to use multiple channels to realize medium access sharing. Then, we propose a multi-channel MAC protocol that meets the requirements of high data rate WSNs, which combines three techniques TDMA, FDMA and CSMA. Indeed, we use a new channel assignment method that enables nodes to choose the most convenient channel in their 3-hop neighborhood in a distributed manner in order to minimize the effects of interferences and collisions. Finally, we evaluate by simulation the performance of our protocol and we compare it to other protocols proposed in the literature. The results show the efficiency of our proposition in the different studied scenarios.L'utilisation des canaux multiples améliore significativement les performances globales des réseaux de capteurs sans fil (RCSF) en permettant des transmissions parallèles sur plusieurs canaux. Cependant, la mise en place d’un protocole MAC multi-canal dans un réseau multisauts nécessite une méthode efficace d’allocation des canaux pour permettre une coordination entre les nœuds afin de partager les canaux disponibles. Dans cette thèse, nous nous intéressons à la conception d’un protocole MAC multi-canal qui répond aux exigences des applications de collecte de données à haut débit dans un réseau multi-saut. Pour ce faire, nous abordons d’abord les principales façons d’utiliser plusieurs canaux pour réaliser le partage du médium. Ensuite, nous proposons un protocole MAC multi-canal, répondant aux exigences des RCSF à haut débit, qui combine les trois techniques TDMA, CSMA et FDMA. En effet, nous utilisons une nouvelle méthode d’allocation des canaux qui permet aux nœuds de choisir le canal de réception le plus convenable dans leurs voisinages jusqu’à 3-sauts d’une façon distribuée afin de minimiser les effets des interférences et des collisions. Enfin, nous évaluons par simulation les performances de notre protocole et nous le comparons à d’autres protocoles proposés dans la littérature. Les résultats obtenus montrent l’efficacité de notre proposition dans les différents scénarios étudiés

Traffic-Aware Channel Assignment in Wireless Sensor Networks

Abstract. Existing frequency assignment efforts in wireless sensor network research focus on balancing available physical frequencies among neighboring nodes, without paying attention to the fact that different nodes have different traffic volumes. Ignoring the different traffic requirements in different nodes in frequency assignment design leads to poor MAC performance. Therefore, in this paper, we are motivated to propose traffic-aware frequency assignment, which considers nodes ’ traffic volumes when making frequency decisions. We incorporate our traffic-aware frequency assignment design into an existing multi-channel MAC, and compare the performance with two conventional frequency assignment schemes. Our performance evaluation demonstrates that traffic-aware channel assignment can greatly improve multi-channel MAC performance. Our trafficaware assignment scheme greatly enhances the packet delivery ratio and system throughput, while reducing channel access delay and energy consumption.