In 10-gigabit-capable passive optical network (XG-PON) power management, performance indexes such as power consumption and state transition delay of cyclic sleep mode are influenced by a sleep period. In this letter, we determine the sleep period to balance the performance tradeoff between these two conflicting goals. To do this, we perform a mathematical analysis using the state probability based on traffic arrivals. The effectiveness of the proposed model is then confirmed by the numerical results of cyclic sleep mode.

In this paper, we evaluate the design and performance of an entirely passive extended 10-gigabit-capable PON (XG-PON) using eight channels of coarse wavelength-division multiplexing (CWDM) in upstream transmission, which is called the Cu-XG-PON, with a first demonstration of the upstream physical layer specification for the extended class in ITU-T G.987 series of recommendations. In the new scheme, a single burst-mode receiver (BMRx) within an optical line terminal (OLT) receives arbitrary upstream data from the optical network terminals (ONTs) divided into eight groups, each group sharing a CWDM wavelength, through a CWDM filter and a power splitter as cascaded remote nodes (RNs) for the upstream link bridge. The downstream link is designed such that a high power OLT transmitter compensates for link loss using two power splitters as cascaded RNs. Based on the proposed architecture, we first analyze the overall system performance in the upstream and downstream links, and then evaluate the practical extension capabilities in terms of fiber distance and split ratio by conducting experiments to probe the upstream performance using a developed BMRx. We demonstrate that the BMRx is capable to -34.5 dBm sensitivity, which is feasible for a 36 dB optical path loss and a 0.5 dB optical path penalty with a 2 dBm ONT transmitter power. Based on the numerical analysis and experimental results, we confirm that the proposed Cu-XG-PON is capable of reaching 28 km for 256 ONTs, or 42 km for 64 ONTs, and furthermore, for ONT groups at long wavelength channels, maximum 40 km for 256 ONTs, or 60 km for 64 ONTs.

In a 10-gigabit-capable passive optical network (XGPON) system, a power management function such as cyclic sleep mode can be implemented to increase energy efficiency of an optical network terminal (ONT). To optimize power saving with the cyclic sleep mode, we proposed an analytic model to determine required ONT buffer size for incoming traffics from user network interface (UNI) when the ONT is sleeping, and to evaluate performances such as power consumption and delay, in accordance with buffer sizes, sleep periods, and arrival rates. Then, by simulating the proposed model, we could estimate the required buffer size and the sleep period for effective implementation of the cyclic sleep mode.

This study investigates a noninvasive continuous glucose monitoring (NI-CGM) system optimized for earlobe application, leveraging the site’s anatomical advantages—absence of bone, muscle, and thick skin—for enhanced optical transmission. The system integrates multimodal sensing, combining near-infrared (NIR) diffuse transmission with temperature and pressure sensors. A novel Multi-Wavelength Slope Efficiency Near-Infrared Spectroscopy (MW-SE-NIRS) method is introduced, enhancing noise robustness through the slope efficiency-based parameterization of NIR signal dynamics. By employing three NIR wavelengths with distinct scattering and absorption properties, the method improves glucose detection reliability, addressing tissue heterogeneity and physiological noise in noninvasive monitoring. To validate the feasibility, a pilot clinical trial enrolled five participants with normal or pre-diabetic glucose profiles. Continuous glucose data capturing pre- and postprandial variations were analyzed using a 1D convolutional neural network (Conv1D). For three subjects under stable physiological conditions, the model achieved 97.0% Clarke error grid (CEG) A-Zone accuracy and a mean absolute relative difference (MARD) of 5.2%. Across all participants, results showed 90.9% CEG A-Zone accuracy and a MARD of 8.4%, with performance variations linked to individual factors such as earlobe thickness variability and physical activity. These outcomes demonstrate the potential of the MW-SE-NIRS system for noninvasive glucose monitoring and highlight the importance of future work on personalized modeling, sensor optimization, and larger-scale clinical validation.

In this letter, a new burst-mode optical receiver with burst detection function is proposed and a single-chip 2.5-Gb/s burst-mode optical receiver has been fabricated using 0.25-μm SiGe bipolar complementary metal-oxide-semiconductor (BiCMOS) technology. The single-chip optical receiver has high sensitivity and wide dynamic range for various classes of power budges required in 10-Gigabit-capable passive optical network (XG-PON1) (2.5-Gb/s upstream and 10-Gb/s downstream data rates). For the 2.5-Gb/s burst-mode data streams, sensitivity and overload were -32 and -4 dBm at a bit-error rate of 10^-10 , respectively, resulting in a dynamic range of 28 dB.