Addressing Energy and Performance Related Challenges in Networked Embedded Systems

Abstract

Networked Embedded Systems comprise of spatially and functionally distributed nodes that are interconnected with one another and with the environment to achieve certain goals. The nodes are connected to one another through wired or wireless communication technologies. This thesis focuses on wireless networks and the challenges encountered in such systems. A node in a wireless network is usually energy-constrained, irrespective of its power source. Hence, schemes that judiciously utilize the energy available at a node to power its peripherals and execute various operations without any performance degradation are required. We have devised energy efficient schemes for data management, accessing network resources, and rendering location based services in a network. A sensor node in a network samples a parameter of interest, followed by transmitting the samples to an aggregator. We have devised an adaptive sampling algorithm that adapts the rate and resolution at which the parameter is sampled based on available energy and its characteristics. Furthermore, we have devised energy and data value-aware algorithms that encourage the selective transmission of data such that fidelity of data recovery is not adversely affected. These schemes not only improve energy utilization but also reduce traffic generated by a node in the network. Before data can be transmitted, nodes are required to perform handshakes on the control channel so that they can access resources for data transmission. The energy consumed while performing these handshakes is often not examined as most of the handshakes are performed only a limited number of times. However, delays in these handshakes affect the ensuing data transmission. .. newline