esa-sceva/satcom-chunk-collection huggingface dataset:
# Real-Time Kinematic Positioning Using Multi-Frequency Smartphone Measurements +
## 1 Introduction  
The diffusion of smartphones providing multifrequency GNSS measurements, including carrier phase observations, has opened new opportunities for the achievement of high-accuracy positioning from low-cost devices. A number of research works have assessed the performance of algorithms exploiting smartphone measurements for Real Time Kinematic (RTK) and Precise Point Positioning (PPP) applications (e.g., [1, 2, 3, 4]). This paper showcases the effectiveness of using GNSS observations from the triple-frequency Huawei P40 Mate smartphone (Huawei, Shenzen, China) for RTK processing under different environments and dynamic conditions.  
Since the quality of the GNSS measurements is affected by the low-quality smartphone antenna, we conducted a preliminary analysis to quantify the antenna's impact on the measurements. Survey and patch antennas were connected to the smartphone under open sky/static conditions for comparison purposes. Several key performance indicators were analysed: the signal power, the Time to First Fix (TTFF), the positioning accuracy, and the percentage of fix solutions using bases at different distances (i.e., 5, 10, and 25 km).  
The results show that, as expected, the GNSS measurement quality is enhanced using external antennas. However, this paper showcases that, even using the smartphone's antenna, about 99% of fix solutions and centimetre positioning accuracy can be achieved by ad hoc tuning the RTK algorithm.  
Moreover, a dynamic test was conducted by fixing the smartphone to the windshield of a tractor and two automotive tests were performed in a rural environment with the smartphone fixed to the car's windshield and roof.  
This paper will discuss the results obtained by the above tests and the tuning of the RTK algorithm for coping with smartphone measurements. Specifically, this paper is structured as follows: Section 2 reports the methodology and the experimental set-up adopted for assessing the performance achieved using smartphone measurements in RTK mode under both static and dynamic conditions. Section 3 reports the results obtained by connecting the smartphone to external antennas of different grades. Sections 4 and 5 discuss the results obtained using the smartphone's internal antenna under both static and dynamic conditions and with different baseline lengths. Finally, Section 6 draws some conclusions.
## 7 Recommendations  
In networks using the Thread protocol, the choice of the communication system (one hop, two hops, or multi-hop) depends on the specific application requirements. On the basis of the results, we have identified a few recommendations regarding the appropriate topology utilization. The one-hop topology is suitable for applications that need low latency and direct communication between a leader node and a router, such as remote control and sensors to the base station. The two-hop topology is beneficial for applications that need extended coverage or communication between the leader node and child nodes located further away, such as home automation, building/campus monitoring systems, distributed industrial IoT applications, and neighborhood area networks. While the multi-hop topology which is based on mesh topology, is ideal for applications that need robustness, scalability, and redundancy, such as industrial monitoring and control, wireless sensor networks, smart city infrastructure, and large-scale deployments. The choice of a communication system will consider factors, such as jitter, packet loss ratio, and round trip time by considering varying bitrate, payload, and link failure to match the specific requirements of each application.  
Overall, the performance evaluation results indicate that the Thread network based on OpenThread and the Raspberry Pi is capable of providing a low packet loss ratio and jitter. The Thread protocol has been tested in various varying conditions to check its performance. One-hop and two-hop topologies perform better than the multi-hop topology having less jitter and packet loss ratio. However, all topologies provide acceptable performance in terms of packet loss rates. Based on these observations, we believe the Thread system can be used for a wide range of applications, as mentioned previously.
## 1 Introduction
### Motivation for the Present Study  
Motivated by these challenges, this study seeks to integrate InSAR, GPR, and ERT, enabling a multi-scale framework to address subsurface instability and leveraging each method's strengths to overcome individual limitations. InSAR provides a zoomed-out perspective on the monitoring capabilities of surface subsidence, while GPR and ERT deliver zoomed-in, high-resolution insights into subsurface anomalies. Using a highway major subsidence case study on Road 431 in Israel, the research aims to bridge the gap between surface and subsurface analyses. This integrated framework addresses current methodological limitations, providing robust insights into infrastructure resilience and sustainable development in geologically complex environments.
# Adaptive Polling Medium Access Control Protocol for Optic Wireless Networks
## 6 Conclusions  
Given the monumental bandwidth available in the visible light spectrum, the VLC has sufficient capacity to address the current Internet capacity demand. In order to realize potential benefits of the VLC, several hurdles must be addressed. These challenges include the design of a novel MAC protocol that considers the physical properties of the OWNs. This study presents the novel non-contention bandwidth assignment protocol named APMAC. The focus of this study is minimization of waiting time and packet collision while increasing system utilization and fairness by exploiting non-contention technique. We consider a simple star topology network with one VLAP and several VLNs. The VLAP is the coordinator while the VLNs act as clients. In order to validate our study, we present numerical results that show the superiority of the protocol we propose against existing protocols such as MT-MAC. Numerical results from simulation show that the APMAC protocol outperforms the MT-MAC in terms of average waiting time. Moreover, APMAC minimizes packet collision, and increases system utilization and fairness significantly.  
D.L.M. conceived, designed and simulated the protocol; K.K. and A.K. contributed to analysis of the protocol and to discuss the results; D.L.M., and K.K. wrote the paper with the aid of A.K. This research received no external funding. The authors declare no conflict of interest.
## 1 Introduction  
Nowadays, wireless body area network (WBANs) systems are becoming very popular research topic because of the applications of it in the field of medical, real-time health monitoring, entertainments. The low power limit (-44.3 dBm) of ultra-wideband (UWB)systems, high data rate, compact size and large bandwidth attract a wide range of applications in short range communications, wearable applications in sensor networks, body area networks, wireless positioning systems, IoT applications, biomedical imaging and high data rate small range communications. For a small period of UWB pulses, it is simple to persuade a high data rate with small latency [1].  
According to Federal Communication Communications (FCC) UWB frequency range is to be from 3.1 GHz to 10.6 GHz [2]. An UWB antenna is the most important element for establishing UWB communications. Important issues remain in terms of interference with narrowband frequency in the UWB frequency regions 3.1-10.6 GHz. UWB experiences from narrow band interference from WiMAX, WLAN and X band satellite communication channels. It is very crucial to filter out these unwanted narrowband signals in order to develop a power-efficient UWB communication system for wireless body sensor networks (BSNs). In body area networks, antennas will be integrated with the sensors for health monitoring purposes [1].  
Antennae are one of the most important components for any wireless communication system. For the design of an efficient UWB system for BSNs, an antenna needs to meet the special requirements in terms of impedance bandwidth, return loss, radiation efficiency, gain and radiation pattern. Recently, there has been tremendous growing research and interest realized for the design of UWB wearable antennas [3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16]. UWB antenna design and radio channel modeling for WBANs have been presented in [3; 4; 5; 6; 7; 8; 9]. Ultra-wideband band north antenna has been pretend in open literature in [12; 13; 14; 15]. However, different authors have used various techniques to integrate band notch in UWB antennas [12; 13; 14; 15]. Still now, there is no breakthrough in the design of UWB suitable band notch antennas. In some articles, authors used band rejection for WiMAX and WLAN [9; 10; 11; 14; 15]. Band rejection technique has been used in UWB antennas for X-band downlink satellite communication systems (7.25-7.75 GHz) [13; 14; 16]. However, mostly UWB band notch antenna designs have been focused on FR4 substrate. Some authors were presented with antennas bigger in size, but these may not be suitable for wearable applications.  
This paper developed and analyzed a novel and very compact Jeans' textile-based band notch UWB wearable antenna for the health monitoring applications in body sensors networks. The antenna has the band notch characteristics for the rejection of X-band downlink satellite communication systems (7.25-7.75 GHz). Simulation-based results of the antenna, including with the antenna structure, have been presented.
# Design and Implementation of a Contextual-Based Continuous Authentication Framework for Smart Homes
## 5 Evaluation Results
### Evaluation 3: Scalability  
In this section, the Gateway is tested for its ability to handle multiple simultaneous requests without bottlenecking access to smart devices. This evaluation demonstrates that the implemented framework is able to handle several simultaneous requests simulated by Apache JMeter, without significantly affecting response times. As shown in Figure 3, the implemented framework is able  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **(A)** & \multicolumn{2}{c}{**(B)**} \\ \hline
**Available Parameters** & **Assigned Weight/100** & **User Security Level** & **Access Threshold/100** \\ \hline Username \& Password & 40 & 4 & 100 \\ Location (proximity) & 30 & 3 & 70 \\ Location (network) & 20 & 2 & 50 \\ Calendar & 10 & 1 & 30 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Example of authentication weights for context and threshold for accessing devices.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Available Parameters** & **Weights** & \begin{tabular}{c} **Confidence** \\ **Level** \\ \end{tabular} & \begin{tabular}{c} **User Security** \\ **Level** \\ \end{tabular} & \
\begin{tabular}{c} **Service** \\ **Security Level** \\ \end{tabular} &
\begin{tabular}{c} **Access** \\ **Decision** \\ \end{tabular} \\ \hline Username, password, and Bluetooth & 40, 30 & 70 & 3 & 2 & Granted \\ Bluetooth and on local network & 30, 20 & 50 & 2 & 2 & Granted \\ Scheduled and on local network & 10, 20 & 30 & 1 & 3 & Denied \\ Username, Password & 40 & 40 (<50) & 1 & 4 & Denied \\ \hline Bluetooth & 20 & 20 & 1 & 2 & Denied \\ \hline Scheduled, Bluetooth and on local network & 10, 30, 20 & 60 (<70) & 2 & 2 & Granted \\ \hline Scheduled, Bluetooth and on local network & 10, 30, 20 & 60 (<70) & 2 & 1 & Granted \\ \hline \hline \end{tabular}
\end{table}
Table 7: Calculated confidence levels and authentication scenarios.  
to handle several simultaneous requests without significantly affecting the response times from our previous trials.  
As shown in Figure 4, the implemented framework stores all historical information that is related to users interacting in any way with the system or various services. This includes, but is not limited to, user logins (both successful and failed), accessed services (both permitted and denied), and new registrations.
## 6 Conclusions  
This study adds comprehensively to current research on the merging of NDN, AI, and C-IoT technologies. This paper's main contribution is the combination of NDN-AI-IoT. It focused on three selected methodological explanations for KITE, the PMSS, and hybrid NeMO. NDNs, rather than being simply an Internet technology, serve a variety of functions, with a focus on consumer-driven network architecture. KITE uses the indirection method to transmit content via simple NDN communication; the PMSS improves producer operations by lowering handover latency; and hybrid NeMO provides a binding information table to replace the base function of forwarding information. In addition, mathematical equations for signaling cost and handover latency were described in this study. The producer mobility operation was highlighted using the network simulator ndnSIM NS-3. Based on the mobility scenario, mathematical equations were developed for each methodology to measure handover latency and signaling cost. We concluded that the hybrid NeMO performs better than KITE and PMSS in terms of handover latency and signaling cost. In the future, this work will be expanded to include additional parameters with a larger network to support scalability and multiple environments.  
**Author Contributions:** Supervision: A.H.M.A.; validation: R.H. and N.M.; visualization and writing of original draft: W.M.H.A.; review and editing: A.H.M.A. and R.H. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This article was supported under the Fundamental Research Grant Scheme FRGS/1/2019/ ICT03/UKM/02/1.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Acknowledgments:** The authors would like to acknowledge the support of the Network Communication Lab Technology Research Groups, FTSM, and UKM in providing facilities for this research. This article was supported under the Fundamental Research Grant Scheme FRGS/1/2019/ICT03/UKM/02/1.  
**Conflicts of Interest:** The authors declare no conflict of interest.  
Figure 12: Average hop count by each method.
# DTN and Non-DTN Routing Protocols for Inter-CubeSat Communications: A comprehensive survey
## 3 Routing Protocols in Connected CubeSat network
### Multi-Layer Routing Protocols in Connected CubeSat Network
The simulation results show that PSNRP outperforms SGRP in terms of achieving minimum end-to-end-delay, lower overhead, and robust link recovery. A Novel Distributed Routing Algorithm (NDRA), which is data-driven-based, was proposed for hybrid LEO/GEO multilayer satellite networks [34]. The algorithm imports a Distributed Routing Algorithm (DRA) that was introduced for virtual node routing and applies it in multilayer architecture. The proposed architecture includes three GEO satellites and 288 LEO satellites to cover the Earth, which is divided into logical locations with the LEO satellites being divided into three groups according to the GEO satellite footprints. These GEO satellites will be used as a one-hop relay to avoid congestion over the LEO links. Additionally, the packets in NDRA are categorised to real-time and non-real-time packets following the packets categorisation idea that was proposed in [44]. The non-real-time packets can be forwarded via the long propagation delay links of GEO, whereas the sensitive real-time packets are forwarded by LEO links. Although NDRA is deemed to have better performance than DRA, this comes at the expense of high overheads at congested satellites [34; 35; 36]. In Reference [45], a congestion prediction technique is proposed to maintain both QoS and load balancing.
# Alluvial Fan Scree Deposits: Formation Characteristics and Erosion Mitigation Strategies
## 4 Anti-Rainfall Erosion Test
### Slope Morphology Impact Assessment (Test Series 2)  
Test series 2 considered slope morphology as the influencing factor, with the mass of eroded soil particles as the indicator. Four slope configurations (planar smooth/rough, curved smooth/rough) were tested under optimal SH dosage (2.0 kg/m\({}^{2}\)) to isolate topographic effects. Specific experimental parameters are outlined in Table 4.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Slope Configurations** & **SH Dosage (kg/m\({}^{2}\))** & **Curing Time** & **Soil Properties** \\ \hline Planar smooth & & Dry density: 1.65 g/cm\({}^{3}\) \\ \hline Planar rough & & Slope: 30\({}^{\circ}\) longitudinal, 0\({}^{\circ}\) cross \\ \hline Curved smooth & & Dimensions: 60 \(\times\) 60 \(\times\) 3 cm \\ \hline Curved rough & & Surface: Planar smooth \\ \hline \hline \end{tabular}
\end{table}
Table 4: Test series 2 parameters.  
Figure 8: Erosion and damage morphology of AFSDs under different SH polymer material spraying quantities. (**a**) 1.0 kg/m\({}^{2}\): Localized scouring (9.69 g loss) at lower quadrant with incipient piping. (**b**) 1.5 kg/m\({}^{2}\): Marginal corner erosion (6.01 g loss), stabilized matrix. (**c**) 2.0 kg/m\({}^{2}\): Negligible detachment (1.03 g loss), intact surficial crust.  
Rainfall erosion test No. 2 explores the impact of four slope surface forms--planar smooth, planar rough, curved smooth, and curved rough--on the mass of eroded soil particles. The erosional damage patterns of AFSDs under the four slope surface forms are shown in Figure 9.  
Under rainfall intensity of 200 mm/h, the soil samples sprayed with 2.0 kg/m\({}^{2}\) of SH polymer material perform well for all four slope surface forms. The slope surfaces remain intact without significant damage, and the erosion amounts are quite low. Specifically, the erosion amounts are 1.66 g for planar smooth, 1.17 g for planar rough, 1.22 g for curved smooth, and 1.16 g for curved rough. This indicates that the 2.0 kg/m\({}^{2}\) SH polymer material is effective under various slope surface forms, demonstrating strong adaptability to different terrains. Based on these findings, our experiments conclusively demonstrate that the effectiveness of the SH polymer material remains largely unaffected by varying terrains. It helps maintain the integrity of reinforced soil during rainfall erosion.
## 3 Overall System
### Specific Features of s-Guard
#### 3.2.2 MCU, Communication Module, and Power Supply  
The printed circuit board (PCB) and circuit schematic of s-Guard are shown in Figure 6. MCU, communication module, power, and other specifications are listed in Table 1. In summary, important features such as 64 Megahertz (MHz) 32-bit Advanced RISC Machine (ARM) Cortex-M4 was used for MCU, Bluetooth 5/Antenna (ANT)/2.4 Gigahertz (GHz) proprietary was used for communication module, and voltage (V) supply of 1.7 to 3.6 V low dropout (LDO) or direct current/direct current (DC/DC) was used for power.  
Figure 4: Cover-sliding type (**a**) and button-sliding type (**b**) 3D design concept model of s-Guard prototype.  
Figure 5: Actually manufactured slide-on prototype model of s-Guard.  
Figure 6: PCB and circuit schematic of proposed s-Guard.
# Optical and SAR Image Registration Based on the Phase Congruency Framework
## 3 Experiments
### Scale and Rotation Variations Experiments of the Proposed Algorithm  
We tested the compatibility of the proposed algorithm with the scale and rotation differences between optical and SAR images.  
Figure 8 and Table 4 show the registration results under the several scale differences for Pair A. We can see that  
In addition, for the optical and SAR image pairs with rotation differences, Table 5 and Figure 9 show the registration results under the various rotation differences for Pair A. From Table 5, excepting the fact that the CMN with the 90\({}^{\circ}\) rotation difference is larger than that of the 60\({}^{\circ}\) rotation difference, CMN decreases with the increase in the rotation difference. As can be seen from Figure 9, there are many correspondences between optical and SAR images with different rotation angles. Table 5 shows that the proposed algorithm can be compatible with the rotation differences between optical and SAR images, ranging from \(-150^{\circ}\) to \(150^{\circ}\).  
In summary, the proposed algorithm is insensitive to geometric and radiometric differences, and can successfully register optical and SAR images with large-scale and rotation differences. However, the proposed algorithm in this paper has not fully covered the full-scale and full-angle differences between optical and SAR images, and we will focus on solving this deficiency in future work.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline
**Rotation Angle/\({}^{\circ}\)** & \(-\)**150** & \(-\)**120** & \(-\)**90** & \(-\)**60** & \(-\)**30** & **0** & **30** & **60** & **90** & **120** & **150** \\ \hline CMN & 16 & 18 & 19 & 23 & 35 & 75 & 43 & 32 & 42 & 26 & 20 \\ \hline \end{tabular}
\end{table}
Table 5: CMNs with different rotation angles between optical and SAR image pair.
## 7 Future Development of TPCTs  
Lower heat loss, higher transfer efficiency, longer work time, and less economic cost are the objectives of the evolution of TPCTs. With global warming and the requirement of improving high-efficiency structures, expectations for stable a TPCT structure are increasing. Based on the evaluation of the cooling performance for the TPCTs structure, the following research directions are proposed:  
1. The utilization of the latent heat of the working fluid: TPCT cooling generally uses liquid convection heat transfer. By combining the two-phase heat transfer of the working fluid with the utilization of its latency, the cooling capacity can be improved.
2. Optimization of the design of the TPCT: according to the needs in engineering, the inner channel design of the TPCT should be optimized to reduce the flow resistance and ensure the uniformity of roadbeds' temperature distributions.
3. Establishment of the ventilation ducts: The ventilation ducts can improve the convection heat transfer efficiency, and then improve the cooling performance of the TPCT roadbeds. An external air system can also be installed.
4. Installation of the solar generator: The improvement of the TPCT with the addition of a solar generator can lead to the long-term use of solar energy to operate the TPCT.
5. Update of the materials: Currently, the material of the TPCT is stainless steel. Improving the corrosion and frost resistance of the material may lead to its longer-term use and reduce the cost.