Claude Roy

Bio: Claude Roy is an academic researcher from École de technologie supérieure. The author has contributed to research in topics: Wireless mesh network & Quality of service. The author has an hindex of 3, co-authored 3 publications receiving 18 citations.

Fast multichannel switching for IEEE 802.11s multiradio wireless mesh networks

Abstract: Wireless mesh networks (WMN) are efficient and low cost solutions for the deployment of broadband access in various environments. To support real-time applications such as multimedia and emergency services, WMNs must provide quality of service (QoS) guarantees and QoS continuity protection. While the capacity of single radio WMNs may severely limit the QoS for such traffic, multiradio WMNs can overcome this restriction and provide additional links to support better QoS mechanisms. This paper describes the design and implementation of a mechanism to switch channel in IEEE 802.11s multiradio WMNs. This semi-centralized mechanism decreases the delays required to switch channels and ensures a continuous connectivity between mesh points and mesh portal points. Intended for self-configuration and self-healing mechanisms, the performance of our new channel switch mechanism is evaluated in a simulated environment. We show that time performance results obtained to optimize topologies or to recover from failures are well below the time constraints of real-time applications.

A study of topology formation in 802.11s multiradio wireless mesh networks

Abstract: Wireless mesh networks (WMN) are efficient and low cost solutions for the deployment of broadband access in various environments. To support real-time applications such as multimedia and emergency services, WMNs must provide quality of service (QoS) guarantees and QoS continuity protection. While the capacity of single radio WMNs may severely limit the QoS for such traffic, multiradio WMNs can overcome this restriction and provide additional links to support better QoS mechanisms. This paper describes two self-configuration mechanisms to establish mesh topologies in IEEE 802.11s multiradio WMNs: a distributed mechanism based on the portal announcement protocol specified in the IEEE 802.11s standard to determine the initial channel assignment of the mesh points forming a backhaul network and a centralized mechanism to optimize the topology initially created once the network is stable. We also study the performance of topology formation in IEEE 802.11s multiradio WMNs and identify the various factors affecting delays in the creation and modification of topologies.

Adaptive multihop scheduling for IEEE 802.11s multiradio cognitive wireless mesh networks

Abstract: Wireless mesh networks (WMN) are efficient and low cost solutions for the deployment of broadband access in various environments. To support real-time applications such as multimedia and emergency services throughout the network, WMNs must provide appropriate quality of service (QoS). While the capacity and the bandwidth availability of single radio WMNs may severely limit QoS for such traffic, multiradio cognitive WMNs (CWMN) can overcome these restrictions and provide better QoS mechanisms. This paper describes a scheduling algorithm with an integrated backpressure mechanism for CWMN. This algorithm ensures that the available bandwidth is properly shared considering the type of traffic to forward, the distance of the clients from the portal and the fluctuating conditions of the links. The performance of our new scheduling algorithm is evaluated in a simulated environment. We show that, while increasing throughput, our algorithm not only achieves nearly perfect fairness, but can also prevent bandwidth wastage.

Data transmission method and station

Abstract: The present invention provides a data transmission method. In the method of the present invention, a station receives an indication frame sent by an access point, where the indication frame is used for allocating a designated random contention channel; a channel state of the designated random contention channel is sensed according to the indication frame; and the station sends data on the designated random contention channel after it is detected that the designated random contention channel is in an idle state. Because in the method of the present invention, a designated random contention channel is allocated to a station, the station can send data on the designated random contention channel, contention among stations is reduced and a time for a station to be connected to a random contention channel is reduced.

A review of scalability and topological stability issues in IEEE 802.11s wireless mesh networks deployments

Abstract: Scalability and topological stability are two of the most challenging issues in current wireless mesh networks WMNs deployments. In the literature, both the scalability and the topological stability of WMNs are described as likely to suffer from poor performance due to the ad hoc nature of the underlying IEEE 802.11 mechanisms. The main contribution of this article is a comprehensive review of the main topological stability and scalability-related issues in IEEE 802.11s-based networks. Moreover, the most relevant proposed solutions are surveyed, where both the drawbacks and the merits of each proposal are highlighted. At the end of the article, some open research challenges are presented and discussed. It is expected that this work may serve as motivation for more and deeper research on these issues to allow the design of future more stable and scalable IEEE 802.11s mesh networks deployments. Copyright © 2015 John Wiley & Sons, Ltd.

A comparative study of channel switching latency for conventional and SDN-based routing in multi-hop multi-radio Wireless Mesh Networks

Abstract: Nowadays, Wireless Mesh Networks (WMNs) have received worldwide acceptance as an attractive paradigm on top of the existing and upcoming wireless technologies. Up to now, a lot of research studies have been conducted on the channel assignment in multi-radio WMNs. To address the destructive impact of interference as an inevitable element of WMNs, it is necessary to reconfigure the wireless radios for switching to the less-congested channels, frequently. Although this problem has been investigated through extensive modeling and simulations, the consequences of channel switching for popular WMN routing schemes have not been assessed sufficiently. In this paper, we present a concise analysis of channel switching latency in multi-hop multi-radio scenarios for OLSR, BATMAN-adv and Open80211s protocols through experimentation testbed. Moreover, we evaluate the functionality of SDN-based WMNs in terms of channel switching delay. The acquired results substantiate that although by using SDN it is feasible to improve the network responsiveness, still the channel switching latency is not negligible.

High Reliability, Low Latency and Cost Effective Network Planning for Industrial Wireless Mesh Networks

Abstract: In this paper, we study high reliability, low latency and cost effective network planning for industrial wireless mesh networks. Based on the requirements of routing reliability, minimum end-to-end delay and reduced deployment cost in wireless mesh networks, such as WirelessHART network, we propose three network planning approaches following the principles of the shortest hops, the least routers and balance of the shortest hops and the least routers, respectively. We then implement the proposed algorithms respectively to generate the network deployment for a given factory layout. Simulation results show that there exists a performance trade-off between these three algorithms. The proposed algorithms have also been implemented and validated in an NS-2 WirelessHART network simulator.

An Economic Framework for Routing and Channel Allocation in Cognitive Wireless Mesh Networks

Abstract: We consider wireless mesh networks with cognitive ability of the wireless routers' radios. The cognitive ability is a cost efficient manner to increase available bandwidth but requires an adaptive bandwidth management mechanism to deal with dynamics of primary users' activities. In this paper, we investigate the joint channel allocation and routing in cognitive wireless mesh networks including the channel reuse opportunities in order to improve the network performance. In particular we propose an economic framework for adaptation and control of the network resources with the goal of network profit maximization. The economic framework is based on the notion of state dependent node shadow price that is derived from Markov decision theory. The node shadow prices are used as routing metrics while their average values are used to allocate the channels among the different nodes. Simulation results illustrate the network profit maximization and effectiveness of the proposed channel allocation scheme that is integrated with a channel reuse algorithm.