Multiscale Timing Estimation for Ad Hoc Networks

Because of the lack of a fixed infrastructure, ad hoc networks use a time synchronization mechanism to start and maintain synchronization. Estimation of time synchronization is one of the key issues in self-organized time division multiple access (SOTDMA) based automatic identification systems (AIS) transceivers. When the primary time source is lost, timing estimation must be performed to maintain system operation. All stations in the network then function as secondary time sources for the failed station. Measuring the time of arrival of a transmitted signal from another station can be treated as a sensor measurement with observation noise. The synchronization state of the station and the signal to noise ratio, related to the distance between two stations, determines the resolution of the measurement. Accordingly, we give the available stations a multiresolution label. By using the concept of multisensor data fusion and a multiresolution technique, we obtain a more accurate time estimate