Tuatara Location-driven Power-adaptive Communication for Wireless Body Area Networks
Abstract : Radio links in Wireless Body Area Networks (WBANs) suffer from both short-term and long-term variations due to the dynamic network topology and frequent blockage caused by body movements, making it challenging to achieve reliable, energy-efficient and real-time data communication. Through experiments with TelosB motes, we observe a strong positive relationship between the channel quality and the position of the sending node relative to the gateway. Motivated by this observation, we design Tuatara, a novel power-aware communication protocol that allows each sensor node to dynamically adjust its transmission power based on the channel status inferred from its instant position, aiming to save energy, reduce interference, and improve communication reliability. Based on a probabilistic model, power level selection is converted to calculate the optimal probability of selecting each power level at a given position, with the objective of minimizing the transmission cost. A reinforcement learning scheme is designed to adaptively update the power level selection probabilities, making Tuatara self-adaptable to changes in the signal propagation environment. Experimental results demonstrate that Tuatara outperforms the state-of-the-art protocols in various scenarios, with performance close to that of the optimal power selection solution even in scenarios where the packet rate is very low.
? We present the core idea of reusing sensor data that already exists in the WBAN to learn about the network state and adaptively reconfigure its parameters.
? The ultimate goal is to have these schemes added as a vertical control plane to existing protocols such as the standard, enabling them to learn, identify and switch between network states.
? The same challenges of wireless channel around the human body exist here. Specifically, the interaction of the prosthesis with surrounding objects would most likely change the channel due to fading.
? Our method reuses the sensor data that already exists in a WBAN to adapt the network to different conditions with minimum overhead.
? To resolve this problem, one feasible solution is to use inviolable network hardware.Our previous work deals with the topology problem and provides an energy-aware topology design for wireless body area networks (EAWD) that minimizes the number of relay nodes and the total energy consumption.
? The cross-technology interference mitigation (CTIM) problem is considered in, involving node mobility, to characterize and solve the interference problem that results on the utilization of different wireless technologies in the same radio spectrum, namely the ISM band.
? Indeed, such a network presents several challenges like the problem of heterogeneous devices and traffic, interference and coexistence, wireless environment properties, etc.
• A realistic body channel emulator that evaluates the path-loss for everyday human activities was developed to assess the efficacy of the proposed techniques.
• The proposed adaptive schemes are specifically beneficial to WBANs as these generally suffer from the highly dynamic channel conditions and are severely constrained in terms of the energy and computation resources.
• However, none of the nodes used in those studies have a biosignal acquisition front-end to enable the implementation of our proposed adaptive schemes.
• In order to show the energy efficiency of our adaptive method, we performed a comparison between scenarios with and without engaging our proposed algorithm.
? Mobility prediction: in mobile scenarios, WBANs connectivity could be altered, and the whole network performance would degrade consequently.
? Training schedules of professional athletes: through the use of equipments helping athletes in training and monitoring of the progress and advancement of their performances.
? Therefore, extensive performance evaluation of CLDO scheme, in dynamic scenarios, is needed to conclude about its suitability for use in BBNs.
? Mobility management is mandatory in a dynamic environment, such as BBNs, where the network topology is changing in a regular or irregular basis, and the mobility of coexisting WBANs could impact the performance of a WBAN of interest.
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