Wireless mesh network

About: Wireless mesh network is a research topic. Over the lifetime, 13600 publications have been published within this topic receiving 221035 citations. The topic is also known as: WMN.

Minimum Latency Broadcasting in Multi-Radio Multi-Channel Multi-Rate Wireless Meshes

Abstract: We address the problem of minimizing the worst-case broadcast delay in multi-radio multi-channel multi-rate (MR2-MC) wireless mesh networks (WMN). The problem of 'efficient' broadcast in such networks is especially challenging due to the numerous interrelated decisions that have to be made. The multi-rate transmission capability of WMN nodes, interference between wireless transmissions, and the hardness of optimal channel assignment adds complexity to our considered problem. We present four heuristic algorithms to solve the minimum latency broadcast problem for such settings and show that the 'best' performing algorithms usually adapt themselves to the available radio interfaces and channels. We also study the effect of channel assignment on broadcast performance and show that channel assignment can affect the broadcast performance substantially. More importantly, we show that a channel assignment that performs well for unicast does not necessarily perform well for broadcast/multicast. To the best of our knowledge, this work constitutes the first contribution in the area of broadcast routing for MR2-MC WMN

A multi-hop wireless mesh network medium access control protocol

Abstract: Systems and methodologies are described that facilitate mitigating a hidden node condition in a wireless mesh network wherein nodes utilize a request-to-send/clear-to-send (RTS/CTS) protocol in conjunction with an asynchronous hybrid automatic repeat request protocol. For instance, a node may contend for a set of subcarriers by sending an RTS signal over the desired subcarriers, and may receive a CTS signal over the contended subcarriers, wherein the CTS signal indicates which subcarriers the node may transmit data over. If another node has won the contention for a particular subcarrier, requesting node may adjust a power level at which it transmits an RTS or a data packet in order to permit the requesting node to utilize the subcarrier without interfering with the winning node.

An advanced smart management system for electric vehicle recharge

Abstract: Recent studies about climate change are mandating a drastic reduction of green house gas (GHG) emissions. Solutions include the utilization of renewable energy sources (e.g., wind, solar energy) and the increased utilization of hybrid and electric vehicles (EVs). In this scenario ICT can play a significant role by fostering the smart utilization of current energy and transportation infrastructures (smart grid and smart cities). This paper presents a new ICT infrastructure to enable the intelligent exploitation of distributed energy resources in order to minimize the EV charging times while optimizing the efficiency of the electrical infrastructure. The proposed system is based on a distributed communication infrastructure (both wired and wireless) aimed at collecting/emitting bidirectional energy dispatching opportunities for electric vehicles. The envisaged system seamlessly interconnects emerging self-organizing wireless technologies (i.e., VANETs and Wireless Mesh Networks), with legacy wired communication technologies, to guarantee a fast rollout of the EV charging service with minimum investments in communication infrastructures. The performance of the proposed solution is evaluated in terms of its sustainability by analyzing the quality of the charging service as perceived by the users, and the capability of the charging infrastructure to meet the charging requests in a timely manner.

An energy-efficient method for nodes assignment in cluster-based Ad Hoc networks

Abstract: One of the most critical issues in wireless ad hoc networks is represented by the limited availability of energy within network nodes. Thus, making good use of energy is a must in ad hoc networks. In this paper, we define as network lifetime the time period from the instant when the network starts functioning to the instant when the first network node runs out of energy. Our objective is to devise techniques to maximize the network lifetime in the case of cluster-based systems, which represent a significant sub-set of ad hoc networks. Cluster-based ad hoc networks comprise two types of nodes: cluster-heads and ordinary nodes. Cluster-heads coordinate all transmissions from/to ordinary nodes and forward all traffic in a cluster, either to other nodes in the cluster or to other cluster-heads. In this case, to prolong the network lifetime we must maximize the lifetime of the cluster-heads because they are the critical network element from the energy viewpoint. We propose an original approach to maximize the network lifetime by determining the optimal assignment of nodes to cluster-heads. Given the number of cluster-heads, the complexity of the proposed solution grows linearly with the number of network nodes. The network topology is assumed to be either static or slowly changing. Two working scenarios are considered. In the former, the optimal network configuration from the energy viewpoint is computed only once; in the latter, the network configuration can be periodically updated to adapt to the evolution of the cluster-heads energy status. In both scenarios, the presented solution greatly outperforms the standard assignment of nodes to cluster-heads, based on the minimum transmission power criterion.

Experimental Comparison of Bandwidth Estimation Tools for Wireless Mesh Networks

Abstract: Measurement of available bandwidth in a network has always been a topic of great interest. This knowledge can be applied to a wide variety of applications and can be instrumental in providing Quality of Service to end users. Several probe-based tools have been proposed to measure available bandwidth in wired networks. However, the performance of these tools in the realm of wireless networks has not been evaluated extensively. In recent years, there has also been some work on estimating bandwidth in wireless networks via passively monitoring the channel and determining the 'busy' and 'idle' periods. However, such tech- niques have primarily been evaluated via simulations only. In this work, we perform an extensive experimental comparison study of both passive and active bandwidth estimation tools for 802.11-based wireless mesh networks. We investigate the impact of interference, packet loss, and 802.11 rate-adaptation, on the performance of these tools. Our results indicate that for wireless networks, a passive technique provides much greater accuracy than the probe-based tools.