An Overview of Wireless Mesh Networks

Wireless mesh networks (WMNs) are communication networks which comprise radio nodes in which nodes are arranged in a mesh topology. Mesh topology is an interconnection of all nodes connected with all other nodes in the network. The network includes devices like nodes, clients, routers, gateways, etc. As the nodes are fully connected, mesh networks are usually less mobile as rerouting is less difficult in predicting the reroute results in delay in data transmission. Mesh clients can be of any wireless devices like cell phones, laptops, etc. The gateways which act as forwarding nodes may not be connected with the Internet. As different devices come under a single network, it is also referred as mesh cloud. WMN is self-healable. It works better with various different networks which include cellular networks and IEEE 802.11, 802.15, and 802.16 as well. WMN is flexible to work with more than one protocol. This chapter gives architecture, layer functionalities, and applications

Nearmesh: network environment aware routing in a wireless mesh network for emergency-response

Wireless Mesh Networks (WMNs) employ hybrid distributed mobile networks with instant deployment and capabilities Such as: self_healing, self_organization and self_configuration. These abilities make WMNs a likely technology for incident communication. An Incident Area Network (IAN) requires a reliable and efficient routing path in an environment, where infrastructure-based communications have been destroyed. Routing awareness plays a significant part in this situation to deliver dynamic disaster facilities. Though, most of the proposed aware routing schemes do not entirely exploit the characteristics of WMNs. In this article, we propose a network environment-aware routing scheme for emergency response (NEARMesh) in WMNs, which employs a network routing information map to select the optimized path, based on cooperative consideration of route awareness information. This scheme is carried out and verified in NCTNus simulator. Imitation outcomes clearly display that the suggested scheme can enhance the network performance by maintaining a high delivery ratio with low latency while reducing the energy ingesting by minimizing network expenses

An Analytical Model for Wireless Mesh Networks with Collision-Free TDMA and Finite Queues

Wireless mesh networks are a promising technology for connecting sensors and actuators with high flexibility and low investment costs. In industrial applications, however, reliability is essential. Therefore, two time-slotted medium access methods, DSME and TSCH, were added to the IEEE 802.15.4 standard. They allow collision-free communication in multi-hop networks and provide channel hopping for mitigating external interferences. The slot schedule used in these networks is of high importance for the network performance. This paper supports the development of efficient schedules by providing an analytical model for the assessment of such schedules, focused on TSCH. A Markov chain model for the finite queue on every node is introduced that takes the slot distribution into account. The models of all nodes are interconnected to calculate network metrics such as packet delivery ratio, end-to-end delay and throughput. An evaluation compares the model with a simulation of the Orchestra schedule. The model is applied to Orchestra as well as to two simple distributed scheduling algorithms to demonstrate the importance of traffic-awareness for achieving high throughput.Comment: 17 pages, 14 figure

Elastic Channel Utilization Against External Radio Interference on SDN-Enabled Multi-Radio Wireless Backhaul Networks

This paper tries to avoid a radio interference while effectively utilizing the resource of interfered channel on SDN-based wireless backhaul networks (WBNs). The densification of small cells on wireless networks is required to handle a lot of traffic for the cloud-based ICT services but inevitably needs a WBN to provide network connectivity at every cell. Since most traffic is delayed or dropped once a WBN suffers from a radio interference coming from outside of the WBN, it is general to avoid using the interfered channel or switch a route spatially. Although such countermeasures are effective to avoid an external radio interference, it could be less effective in terms of resource utilization because the interfered channel may still remain resource. From this perspective, we propose a method that estimates the residual resource of interfered channel and uses it as much as possible while avoiding the effect arising from the radio interference. Specifically, our proposed method uses the information about incoming/outgoing traffic to estimate the residual resource and migrate a part of traffic to another channel until the amount of incoming traffic and that of outgoing packets are balanced (i.e., the channel is not a bottleneck anymore). The experimental results showed that our method is able to estimate the residual resource of interfered channel and effectively use it even under external radio interference.7th IEEE International Conference on Cloud Networking (CloudNet 2018), 22-24 October, 2018, Tokyo, Japa

Monitoring pour pompiers: travail de bachelor : diplôme 2016

Dans l'exercice de leur métier, les pompiers et les services de secours sont amenés à se déplacer dans des environnements hostiles et dangereux. Dans ces conditions, un suivit par un pompier nommé « surveillant » est indispensable afin de garantir la sécurité des intervenants. De nos jours, ce suivit est réaliser à l’aide d’une radio. Les pompiers qui interviennent sont équipés d’un appareil respiratoire isolant (ARI) et transmettent par radio les quantités d’air restantes dans les bouteilles. Le « surveillant » prend note de ces informations sur une feuille de papier. Ce projet propose de monitorer en temps réel à l’aide des paramètres d’un body area network sans fil déployé sur les pompiers. Ce réseau de capteurs permettra de monitorer les paramètres physiologiques et environnementaux de chaque pompier avec des informations sur le pouls, la température, le niveau d’air du système respiratoire ou en encore la présence de danger spécifiques comme des gaz toxiques. Ces informations seront ensuite rapatriées via la transmission LoRa sur une tablette dans le poste de commandement