Cross-Layer Design for Smart Routing in Wireless Sensor Networks
Marwan Omar, A. A. Samy · InTech eBooks · 2012
Wireless Sensor Networks / Book 1 Next-generation sensor networks require performance optimization by considering both the potential performance that can be achieved and the corresponding impact on a node's energy capacity.This enables nodes to make more informed resource allocation decisions.With that said, the dependencies of next-generation applications on various performance and energy factors vary.Many of these applications are critical and require immediate response such as those for physical security, industrial processes and infrastructure monitoring; however, those for temperature control and ambient light measurement, for example, are less critical and are able to conserve energy at the expense of less performance-heavy resource allocation.Hence, the aim is to create a flexible cross-layer platform for distributed WSNs that considers the criticality of the resource allocation for next-generation applications.This chapter covers the main research areas that arise in designing smart routing protocols and require specific engineering attention:• Network Architecture -determining the optimal configuration of the distributed architecture and the deployment of WSNs at areas of interest to extend the WMN;• Optimization Metrics -identifying cross-layer performance and energy factors that impact resource allocation: application requirements, available routes, channel quality, battery life, physical (PHY) layer considerations (transmit power, operating channel and bandwidth), and the energy efficiency of the wireless communication protocol;• Criticality -defining the dependency of commercial applications on performance and energy considerations;• Route Selection -selecting the route with the optimal trade-off between performance and energy conservation for a given application criticality;• Coexistence -providing connectivity between heterogeneous communication interfaces to bridge sensor and mesh technologies such as Bluetooth and WiMax, respectively; and,• Energy Harvesting -quantifying the impact of replenishing energy reserves from kinetic, solar or heat energy on resource allocation.Each of these topics will be covered in this chapter. Network architectureWireless mesh networks (WMNs) are the architectural enabler for wireless sensor networks (WSNs).As mentioned, WMNs provide the opportunity to deploy WSNs in an incremental fashion to execute sensory applications at multiple locations of interest on a per-need basis; WMNs also provide an alternative to carrying Internet Protocol (IP) traffic in rural or hostile environments where access to fibre may not be available.This provides feedback of sensory data from a WSN to a centralized controlling station over a long haul through a mesh node that is assigned to govern a sensor cluster.These specially-assigned mesh nodes, called cluster-heads, are selected based on proximity, or deployed to extend the network, to the sensory location(s) of interest.Cluster-heads provide a bridge to the mesh network and may assume supervisory control of their subordinate sensors, which are typically limited in their resources and computational capabilities.To perform these functions, cluster-heads are equipped with the additional resources to handle the traffic load, 190 Wireless Sensor Networks -Technology and Protocols Cross-Layer Design for Smart Routing in Wireless Sensor Networks 3 Cross-Layer Design for Smart Routing in Wireless Sensor Networks 5