Node localization through physical layer network coding: Bootstrap, security, and accuracy

Previous research on physical layer network coding (PNC) focuses on the improvements in bandwidth usage efficiency. Its capability to assist wireless nodes in localization was first discussed in [1]. In that paper, however, the authors discussed only the basic idea to detect and separate the interfered signals for calculating the node positions. Many important issues to turn the idea into a practical approach are not extensively studied. In this paper, we plan to investigate these problems. Specifically, our research focuses on the bootstrap procedures, security, and localization accuracy of the PNC based mechanism. We first study the required node density to bootstrap the localization procedure in both infrastructurebased and self-organized networks. With this question answered, researchers can recognize the network scenarios to which PNC based localization can be applied. We design mechanisms to protect integrity of the exchanged information and defend against node impersonation attacks so that the localization procedures will be robust against malicious activities. For localization accuracy, we study the negative impacts of the position errors of the anchor nodes. We design two mechanisms to reduce the localization inaccuracy for both individual nodes and cumulative procedures through excluding the anchor nodes with positioning errors and introducing multiple bootstrap areas. Both simulation and theoretical analysis are used to support our investigation. This research shows that PNC based node localization can satisfy the security and accuracy requirements of different types of wireless networks and it can be widely deployed. 2012 Elsevier B.V. All rights reserved.