ADAM: Administration and Deployment of Adhoc Mesh Networks

Costly on-site node repairs in wireless mesh networks (WMNs) can be required due to misconfiguration, corrupt software updates, or unavailability during updates. We propose ADAM as a novel management framework that guarantees accessibility of individual nodes in these situations. ADAM uses a decentralised distribution mechanism and self-healing mechanisms for safe configuration and software updates. In order to implement the ADAM management and self-healing mechanisms, an easy-to-learn and extendable build system for a small footprint embedded Linux distribution for WMNs has been developed. The paper presents the ADAM concept, the build system for the Linux distribution and the management architecture.

Evaluating the Trade-off Between Energy Efficiency and QoE in Wireless Mesh Networks

The increasing usage of wireless networks creates new challenges for wireless access providers. On the one hand, providers want to satisfy the user demands but on the other hand, they try to reduce the operational costs by decreasing the energy consumption. In this paper, we evaluate the trade-off between energy efficiency and quality of experience for a wireless mesh testbed. The results show that by intelligent service control, resources can be better utilized and energy can be saved by reducing the number of active network components. However, care has to be taken because the channel bandwidth varies in wireless networks. In the second part of the paper, we analyze the trade-off between energy efficiency and quality of experience at the end user. The results reveal that a provider's service control measures do not only reduce the operational costs of the network but also bring a second benefit: they help maximize the battery lifetime of the end-user device.

VirtualMesh: An Emulation Framework for Wireless Mesh Networks in OMNeT++

Wireless Mesh Networks (WMN) have proven to be a key technology for increased network coverage of Internet infrastructures. The development process for new protocols and architectures in the area of WMN is typically split into evaluation by network simulation and testing of a prototype in a test-bed. Testing a prototype in a real test-bed is time-consuming and expensive. Irrepressible external interferences can occur which makes debugging difficult. Moreover, the test-bed usually supports only a limited number of test topologies. Finally, mobility tests are impractical. Therefore, we propose VirtualMesh as a new testing architecture which can be used before going to a real test-bed. It provides instruments to test the real communication software including the network stack inside a controlled environment. VirtualMesh is implemented by capturing real traffic through a virtual interface at the mesh nodes. The traffic is then redirected to the network simulator OMNeT++. In our experiments, VirtualMesh has proven to be scalable and introduces moderate delays. Therefore, it is suitable for predeployment testing of communication software for WMNs.

An Evaluation of Compression Schemes for Wireless Networks

Data gathering, either for event recognition or for monitoring applications is the primary intention for sensor network deployments. In many cases, data is acquired periodically and autonomously, and simply logged onto secondary storage (e.g. flash memory) either for delayed offline analysis or for on demand burst transfer. Moreover, operational data such as connectivity information, node and network state is typically kept as well. Naturally, measurement and/or connectivity logging comes at a cost. Space for doing so is limited. Finding a good representative model for the data and providing clever coding of information, thus data compression, may be a means to use the available space to its best. In this paper, we explore the design space for data compression for wireless sensor and mesh networks by profiling common, publicly available algorithms. Several goals such as a low overhead in terms of utilized memory and compression time as well as a decent compression ratio have to be well balanced in order to find a simple, yet effective compression scheme.

Real-World Energy Measurements of a Wireless Mesh Network

Over the past several years the topics of energy consumption and energy harvesting have gained significant importance as a means for improved operation of wireless sensor and mesh networks. Energy-awareness of operation is especially relevant for application scenarios from the domain of environmental monitoring in hard to access areas. In this work we reflect upon our experiences with a real-world deployment of a wireless mesh network. In particular, a comprehensive study on energy measurements collected over several weeks during the summer and the winter period in a network deployment in the Swiss Alps is presented. Energy performance is monitored and analysed for three system components, namely, mesh node, battery and solar panel module. Our findings cover a number of aspects of energy consumption, including the amount of load consumed by a mesh node, the amount of load harvested by a solar panel module, and the dependencies between these two. With our work we aim to shed some light on energy-aware network operation and to help both users and developers in the planning and deployment of a new wireless (mesh) network for environmental research.

Green Wireless-Energy Efficiency in Wireless Networks

Wireless networks have become more and more popular because of ease of installation, ease of access, and support of smart terminals and gadgets on the move. In the overall life cycle of providing green wireless technology, from production to operation and, finally, removal, this chapter focuses on the operation phase and summarizes insights in energy consumption of major technologies. The chapter also focuses on the edge of the network, comprising network access points (APs) and mobile user devices. It discusses particularities of most important wireless networking technologies: wireless access networks including 3G/LTE and wireless mesh networks (WMNs); wireless sensor networks (WSNs); and ad-hoc and opportunistic networks. Concerning energy efficiency, the chapter discusses challenges in access, wireless sensor, and ad-hoc and opportunistic networks.

Authentication and Authorisation Mechanisms in support of Secure Access to WMN Resources

Over the past several years, a number of design approaches in wireless mesh networks have been introduced to support the deployment of wireless mesh networks (WMNs). We introduce a novel wireless mesh architecture that supports authentication and authorisation functionalities, giving the possibility of a seamless WMN integration into the home's organization authentication and authorisation infrastructure. First, we introduce a novel authentication and authorisation mechanism for wireless mesh nodes. The mechanism is designed upon an existing federated access control approach, i.e. the AAI infrastructure that is using just the credentials at the user's home organization in a federation. Second, we demonstrate how authentication and authorisation for end users is implemented by using an existing web-based captive portal approach. Finally, we observe the difference between the two and explain in detail the process flow of authorized access to network resources in wireless mesh networks. The goal of our wireless mesh architecture is to enable easy broadband network access to researchers at remote locations, giving them additional advantage of a secure access to their measurements, irrespective of their location. It also provides an important basis for the real-life deployment of wireless mesh networks for the support of environmental research.