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.

Radio frequency location determination system and method with wireless mesh sensor networks

Abstract: A radio frequency (RF) system and method for determining the location of a wireless node in a wireless mesh sensor network is disclosed. The wireless node can be a wireless terminal, a wireless transceiver, or a wireless transmitter. The wireless network includes a plurality of wireless nodes linked to a digital computer, such as, for example, a server or a location processor, via a communications link. The method comprises deploying a plurality of identifier wireless nodes each at a predetermined location. Node-to-node data for the wireless nodes are generated, the node-to-done data providing information regarding a wireless node's communication with other wireless nodes. The node-to-node data is transmitted to the digital computer where the node-to-node data is processed to generate a map identifying the locations of the wireless nodes.

Frequency agility in a ZigBee network for smart grid application

Abstract: Smart grid is an intelligent power generation, distribution and control system. ZigBee, as wireless mesh networking scheme low in cost, power, data rate, and complexity, is ideal for smart grid applications. Unfortunately, almost all ZigBee channels are overlapped with wireless local area networks (WLAN) based on 802.11 specifications, resulting in significant service degradations in interference scenarios. We propose a frequency agility-based interference avoidance algorithm, which utilizes Energy Detection (ED) and active scan to perform smart channel selection. This algorithm can detect interference and adaptively switch nodes to “safe” channels to dynamically avoid WLAN interference. Our proposed scheme was empirically evaluated in terms of the packet error rate (PER) using a ZigBee and Wifi coexistence testbed, and the results were compared with our analytical results. The measurement results show the algorithm efficiently mitigates the effect of WiFi interference upon ZigBee networks.

A simulation system for WMN based on SA: performance evaluation for different instances and starting temperature values

Abstract: With the emergence of wireless networking paradigm, several optimisation problems are showing their usefulness to the efficient design of such networks. These problems are related, among others, to optimising network connectivity, coverage and stability. The resolution of these problems turns out to be crucial for optimised network performance. In the case of wireless mesh networks (WMN), such problems include computing placement of nodes (mesh router nodes, gateways and distribution of mesh client notes), so that network performance is optimised. Previously, we have proposed and implemented a simulation system, which uses simulated annealing (SA) algorithm, to optimise network performance by computing mesh routers’ positions in wireless mesh networks (WMNs). We consider different temperature values and different instances in our simulations. In this work, we use the WMN-SA system to find the optimal distribution of router nodes in order to provide the best network connectivity and the best coverage for distributed mesh clients. From simulation results, we found that when the size of the instance increases, the size of GC and NCMC decrease. Moreover, the larger instances are affected more by higher temperatures.

Forwarding techniques for IP fragmented packets in a real 6LoWPAN network.

Abstract: Wireless Sensor Networks (WSNs) are attracting more and more interest since they offer a low-cost solution to the problem of providing a means to deploy large sensor networks in a number of application domains. We believe that a crucial aspect to facilitate WSN diffusion is to make them interoperable with external IP networks. This can be achieved by using the 6LoWPAN protocol stack. 6LoWPAN enables the transmission of IPv6 packets over WSNs based on the IEEE 802.15.4 standard. IPv6 packet size is considerably larger than that of IEEE 802.15.4 data frame. To overcome this problem, 6LoWPAN introduces an adaptation layer between the network and data link layers, allowing IPv6 packets to be adapted to the lower layer constraints. This adaptation layer provides fragmentation and header compression of IP packets. Furthermore, it also can be involved in routing decisions. Depending on which layer is responsible for routing decisions, 6LoWPAN divides routing in two categories: mesh under if the layer concerned is the adaptation layer and route over if it is the network layer. In this paper we analyze different routing solutions (route over, mesh under and enhanced route over) focusing on how they forward fragments. We evaluate their performance in terms of latency and energy consumption when transmitting IP fragmented packets. All the tests have been performed in a real 6LoWPAN implementation. After consideration of the main problems in forwarding of mesh frames in WSN, we propose and analyze a new alternative scheme based on mesh under, which we call controlled mesh under.

Design of a WDM network using a multiple ring approach

Abstract: This paper introduces a new all-optical network design approach using a multiple ring concept as an alternative to the present mesh network scheme. It is shown that several different design alternatives using multiple rings exist and they can be classified into two categories according to the way in which the traffic is accommodated. The one that offers the most simple control and management has been investigated and is discussed here. It is shown that this approach can be very useful for the design and implementation of wavelength division multiplexing networks as it offers many useful advantages of the ring structure while is still able to achieve the high efficiency of network bandwidth usage due to high connectivity in the mesh topology. For example, in the sample network considered here the multiple ring scheme only requires less than 10% extra capacity in comparison to the pure mesh design.