A novel sensor network architecture
Sudhaakar, Raghuram S
MetadataShow full item record
Wireless sensor devices are becoming an integral part of the human environment and their seamless integration has created a range of new Wireless Sensor Network (WSN) architectures. The Medium Access Control (MAC) protocol is a key component of WSN's, as it critically affects important characteristics like lifetime of the network, throughput guarantees and cost effectiveness. In this thesis we attempt to design new MAC protocols for emerging WSN architectures and applications. A sensor network can be functionally described as a heterogeneous collection of devices that collect and exchange data . Based on this functional distinction we propose to classify the network into two tiers—(i) a class of resource constrained devices that collect data and (ii) a class a devices whose main function is to exchange and propagate the collected data through the network. First, we consider data collection using resource constrained nodes and study the problem of providing a guaranteed delivery probability and differentiated QoS to nodes that do not have the capability to receive any signals. We develop a new MAC protocol based on stochastic methods to solve this problem and show that we can achieve good performance for densely deployed networks. We also study extensions of the protocol that use multiple channels and rudimentary BPSK receivers to improve the system capacity. Secondly, we study data intensive networks in which the nodes require guaranteed QoS in terms of throughput and delay. Although there exist many protocols that meet these requirements, all of them require some form of centralized control. Specifically, we study the problem of high data rate communication in a completely distributed manner, with no form of centralized control. To solve this problem we develop a TDMA based protocol and algorithms that can provide distributed contention free channel access. Finally, we apply these MAC protocols to practical applications and study their performance in field deployments. This provides a significant insight into the performance, benefits and drawbacks of these protocols. We hope the lessons learnt will be a valuable input to the design of protocols for next generation networks.