Car Safe

The Car Safe project helps protect parents and caretakers from the dangers associated with leaving children in hot vehicles. The device supports parents through notifying them of the child’s wellbeing and status while within an automobile. Specifically, the device monitors the child’s ergonomic experience and the spatial proximity between the caretaker and child. Car Safe utilizes this information and determines if the child finds himself in a dangerous environment. Due to its compact design, the device functions independently of a specific car seat design, allowing customers to integrate Car Safe in the car seat environment of their choosing

Performance Evaluation of Bluetooth Systems with LDI, Modified LDI, and NSD Receivers ∗

Abstract — Bluetooth is a popular short-range, low-power radio standard for wireless personal area networks (WPANs). Bluetooth transmitters employ Gaussian frequency shift keying (GFSK) and simple block codes for error correction. Recently, two new receiver designs for Bluetooth devices, the so-called modified limiter-discriminator detector with integrate-and-dump filtering (LDI) and noncoherent sequence detection (NSD) have been proposed in the literature. While the modified LDI receiver is a concatenation of a conven-tional LDI detector with an improved error-correction decoder, the NSD receiver fully takes the memory introduced by GFSK into account. Both receivers have been shown to improve the Bluetooth system performance in terms of physical-layer (PHY) metrics such as bit-error rate and packet-error rate. In this paper, we present a comprehensive performance evaluation considering practically more relevant metrics such as throughput, delay, and delay jitter at the medium-access control layer (MAC). To this end, we develop an evaluation framework, which includes the spatial distribution of Bluetooth devices, path loss, fading, realistic data traffic models, scheduling, automatic repeat request (ARQ), and baseband packet selection. Our numerical and simulation results verify that the newly introduced Bluetooth receivers, especially NSD, offer a significant performance enhancement for Bluetooth systems in terms of practically relevant measures