LiDAR perception for autonomous driving applications offers highly accurate scene depiction in three-dimensional (3D) spaces, whose most representative task is LiDAR panoptic segmentation (LPS), as it offers exhibition of both instance- and semantic-level segmentation in a holistic manner. Although previous approaches have achieved mature performance, no research has explored temporal information for enhancing LPS performance. As multi-frame processing can assist in better predictions in terms of feature representation and recursive forecasting, which has been proven in other LiDAR perception challenges, this study proposes an effective and temporal-aware panoptic segmentation method for LiDAR point clouds. Specifically, we introduce two modules: convolution-based cross-frame fusion attention (CFFA) and adjacent shifted feature encoder (ASFE) modules. The CFFA module can fuse multi-frame features on the basis of the idea of convolution-based attention, whereas the ASFE module leverages adjacent model outputs and serves as an intermediate guide for final segmentation predictions. Consequent to our extensive experiments, the two modules have been reaffirmed in terms of their productivity in the realm of the LPS. The proposed LPS model achieves impressive panoptic-quality metric scores that are evaluated on different popular benchmarks (63.36% under SemanticKITTI and 78.54% under Panoptic nuScenes), outperforming previous state-of-the-art methods by a significant margin. Further quantitative and qualitative analyses provide evidence of the advantages of multi-frame processing for the LPS together with demonstrations of its particular behavior under different settings.

In a wireless channel with a large delay spread, a detection probability of conventional TDoA (Time Difference of Arrival) positioning algorithms cannot satisfy the U.S. E-911 (Enhanced-911) standard. In this paper, we propose an improved TDoA-based tracking algorithm for mobile-WiMAX (Worldwide Interoperability for Microwave Access) systems. The position of a MS (Mobile Station) is estimated by the network-based TDoA location scheme when the MS is located in the GPS (Global Positioning System) shadow area. The proposed algorithm compares the estimated position of a current state to the previous states, for achieving high reliability. Simulation results show that the proposed algorithm can improve the detection probability about 10% points, compared to the conventional TDoA-only positioning algorithm in the ITU-R (International Telecommunication Union-Radiocommunication sector) micro-cell environment, using the Pedestrian-B channel model which has a large delay spread profile. The proposed scheme's improvement helps to satisfy the E-911 standard when utilizing information from three RASs (Radio Access Stations).

We propose an efficient video adaptive streaming (VAST) Algorithm which can be used in FTTx broadband access networks. To serve video-on-demand (VoD) users, the algorithm uses a patching scheme to save on network bandwidth for video streaming, and increases the efficiency by adaptively changing the speed of patch streams and patching window based on time of the day and video popularity. To analyze the algorithm, we consider a 2.488-Gbps GPON network providing VoD service to 512 households. We use a daily video request model and a video popularity model to determine the adaptive streaming speed and dynamic patching window. Numerical results show that, when the available network bandwidth is reduced below the required level due to background traffic, the algorithm can considerably reduce the average user waiting time and the number of waiting requests.

In this paper, we propose the ADRX (adaptive discontinuous reception) mechanism with the EPI (extended paging indicator) for power saving in the UMTS (universal mobile telecommunications system). Regardless of various traffic patterns and network situations, the conventional FDRX (Fixed DRX) mechanism currently specified by 3GPP (third generation partnership projects) employs only fixed DRX period with a given DRX cycle length of the same length in which each UE (User Equipment) is to have one paging occasion with the uniquely allocated PI. However, improvement of power saving performance cannot be expected since this FDRX does not support longer DRX periods to save more power consumed in the UE for intermittent data packets. In the proposed ADRX mechanism, to solve this problem and efficiently reduce the power consumption, DRX period is easily controlled by the EPI which is decided by Node B considering the current traffic situation. In addition to its original functions to indicate paging messages, the proposed EPI also includes four extended functions; preservation, increase, decrease, and reset of the DRX periods. Simulation results reveal that the proposed ADRX mechanism achieves remarkable improvement of power saving performance as compared to the conventional FDRX mechanism. Furthermore, it is also observed that the proposed ADRX based on the EPI has a trade-off relationship between power saving performance and packet transmission reliability.

We address the issue of how to provide quality of service (QoS) with limited fiber delay lines (FDLs) at the WDM layer. We propose an offset-time-based scheme, which is less complex and more scalable than existing buffer-based schemes. The proposed scheme does not mandate any buffer at the intermediate nodes, but can take advantage of FDL-based buffers, and thus is suitable for optical networks. We discuss a couple of structures of the FDL "buffers" (which differ from the conventional queues), and evaluate their effectiveness. Specifically, the offset time required for class isolation when reserving resources such as wavelengths and FDLs is quantified. The effect of having limited FDLs on the offset time-based scheme is measured in terms of the burst loss probability and queuing delay as a function of the offset time, the maximum delay time of FDLs, the number of FDLs, and the number of wavelengths.

We address the issue of how to provide basic quality of service (QoS) in optical burst-switched WDM networks with limited fiber delay lines (FDLs). Unlike existing buffer-based QoS schemes, the novel offset-time-based QoS scheme we study in this paper does not mandate any buffer for traffic isolation, but nevertheless can take advantage of FDLs to improve the QoS. This makes the proposed QoS scheme suitable for the next generation optical Internet. The offset times required for class isolation when making wavelength and FDL reservations are quantified, and the upper and lower bounds on the burst loss probability are analyzed. Simulations are also conducted to evaluate the QoS performance in terms of burst loss probability and queuing delay. We show that with limited FDLs, the offset-time-based QoS scheme can be very efficient in supporting basic QoS.