Maximum-Likelihood Estimator of Clock Offset between Nanomachines in Bionanosensor Networks

Abstract

Recent advances in nanotechnology, electronic technology and biology have enabled the development of bio-inspired nanoscale sensors. The cooperation among the bionanosensors in a network is envisioned to perform complex tasks. Clock synchronization is essential to establish diffusion-based distributed cooperation in the bionanosensor networks. This paper proposes a maximum-likelihood estimator of the clock offset for the clock synchronization among molecular bionanosensors. The unique properties of diffusion-based molecular communication are described. Based on the inverse Gaussian distribution of the molecular propagation delay, a two-way message exchange mechanism for clock synchronization is proposed. The maximum-likelihood estimator of the clock offset is derived. The convergence and the bias of the estimator are analyzed. The simulation results show that the proposed estimator is effective for the offset compensation required for clock synchronization. This work paves the way for the cooperation of nanomachines in diffusion-based bionanosensor networks.

A Time-Slotted Molecular Communication (TS-MOC): Framework and Time-Slot Errors

“…The perturbation-invariant behavior suggests that the initial perturbations do not affect the performance. A similar observation was also reported in [18], which supports our observations and implies that SIT-Algn and RIT-Algn are robust to perturbations. Evidently, that observation makes us believe that while the proposed SIT-Algn and RIT-Algn schemes are not designed to estimate the perturbations and do not utilize time-stamped messages, they can to some degree inherently counteract the perturbations.…”

“…Through MUCIN, we simulated and recorded the propagation delays experienced by the signals. Then, we built an event-driven simulator that implements the events described in (4) to ( 10) and ( 14) to (18). For the detailed working of MUCIN, we direct the readers to the main literature [30].…”

“…To highlight the effectiveness of the proposed schemes, we compare their performances with an MLE-based synchronization scheme [18]. The rationale for choosing [18] as the comparing scheme is mainly for two reasons. Firstly, for the fact that they also consider clock offsets as the only source of perturbations in the oscillators.…”

“…Substituting ( 14) and ( 17) in ( 3), the t att can be obtained as By obtaining the t att through (18), the SN can proceed to perform a signal transmission such that the signal will arrive at the expected t bgn . Substituting ( 14) -( 17) in ( 18) and rearranging in terms of P C and P A yields…”

Coding in Diffusion-Based Molecular Nanonetworks: A Comprehensive Survey

“…While network coding studies in the context of DBMC nanonetworks are surveyed in detail in Section IX, we briefly sketch here the historical developments. The beginning of nanonetworks was represented in particular by the so-called wireless sensor networks [160]-with nodes becoming smaller and smaller. In this context, collections of highly distributed, small, and lightweight wireless sensor nodes monitoring the environment or systems based on physical measurements are referred to as a wireless sensor network [161], [162].…”