بحوث سكوبس — ا.د عبد الكريم عبد الرحمن كاظم اللامي

Time-Sensitive Networking (TSN) is an IEEE 802.1 standard set to provide deterministic data transmission over Ethernet-based networks. In TSN, Strict Priority (SP) scheduling is a fundamental technique ensuring high-priority traffic to be transmitted before low-priority traffic. This prioritization strives for low-latency communication for critical applications, such as industrial automation and automotive systems. This scheduling algorithm operates by assigning each frame a priority level of eight priorities and processing frames in descending order of priority, effectively creating a hierarchical transmission model with a constant queue number (8 queues). This paper investigates the performance of standard SP. In addition, it proposes a novel Synchronized Strict Priority with Dynamic Queues (S-SPDQ) scheduling for optimizing the processing delay as a part of the overall system latency, which is especially relevant for Wireless TSN (WTSN). The proposed algorithm was implemented as a bare-metal program on ESP32S2 which is a 32-bit Xtensa LX7 microcontroller. The SS-PDQ scheduling improves the SP model by introducing queue dynamicity to minimize overall latency and implementing time-based synchronization to ensure precise transmission delay estimation, paving the way for future enhancements in time-aware algorithms. Compared with the standard SP, the S-SPDQ introduced an average reduction in memory consumption by 50%, in the dequeuing process time by 49%, and the transmission delay by 12%. For the end-to-end latencies in selected use cases, the average reduction is 17% for 1 -queue, 15% for 4-queues and 12% for 7-queues. © 2025 IEEE.

Smart Health Sensor Networks (SHSNs) are pivotal in real-time health monitoring, enabling the continuous collection and transmission of sensitive physiological data. To ensure reliability and longevity in such systems, both security and energy efficiency must be optimized. Existing clustering methods often lack robust trust evaluation mechanisms, making them vulnerable to malicious nodes and leading to rapid energy depletion and compromised data integrity. To address these limitations, this paper introduces a novel Trust-aware Secure Energy Optimization Framework (TSEOF) that integrates trust evaluation with hierarchical clustering. The proposed TSEOF dynamically assesses the trustworthiness of nodes based on behavioral metrics and incorporates this trust score into the clustering process to isolate unreliable nodes. This approach enhances network longevity and data accuracy by selecting only trustworthy and energy-efficient nodes as cluster heads. Simulation results demonstrate that TSEOF significantly improves energy efficiency, reduces data loss due to malicious activities, and extends the overall network lifetime compared to traditional methods. The framework ensures secure communication with minimal computational overhead, making it ideal for real-time health monitoring applications. © 2025 IEEE.

Positioning and accurate time delay measurement techniques have been used with the Internet of Things (IoT) and embedded systems due to their importance in providing location information for the communicating nodes. In the last two decades, positioning techniques were introduced using the Received Signal Strength Indicator (RSSI) of Wi-Fi signals and time-based techniques. Fine Timing Measurement (FTM) is the most important time-based technique, which relies on the captured timestamps during the messaging between nodes. Thus, in addition to its originally intended application for wireless localization, it can be used for the future of Wi-Fi Time Sensitive Networking (WTSN), where low latency, low jitter, and precise time synchronization play an important role in Industrial IoT (IIOT)-oriented applications. The presented work considers FTM's behavior and performance measurements, especially in a factory environment with different room sizes. An Automated Physical Test Bed (APTB) and emulated multipath propagation model based on ITU-R radio wave propagation standard for the factory environment are considered in the work. The results show that the FTM performance is noticeably affected by multipath signal propagation, thus increasing RTT, delay, and fluctuation in jitter and resulting in a noticeable degradation in RSSI. In contrast, the total number of correctly received frames is not affected, indicating the efficiency and reliability of the Wi-Fi FTM technique. © 2024 IEEE.

To accomplish the targets of Beyond Fifth-Generation (B5G) networks, considerable spectral efficiency, wide coverage, better reliability, and energy efficiency are the main objectives. In order to enhance the performance of the Orthogonal Frequency Division Multiplexing (OFDM) signal in terms of Bit Error Rate (BER), powerful channel coding, such as polar coding, must be considered. In addition, a Massive Multi-Input Multi-Output (MMIMO) combined with OFDM can support better performance and spectral efficiency. On the other hand, Physical Layer Network Coding (PLNC) can increase system throughput. This paper explores the integration of Polar-Coded OFDM (PCOFDM) with MMIMO and PLNC to enhance transmission reliability and throughput. A two-way relay transmission scenario is considered at millimeter Wave (mmWave) frequencies. The consequences of the extensive simulation assessments for Multilevel Quadrature Amplitude Modulation (M-QAM) demonstrated that refinements in throughput and BER can be performed using PCOFDM, with PLNC having enough antenna elements in the massive MIMO system at the base station (the relay node). In any case of the number of antenna elements utilized in the user terminal, the BER achievement of PCOFDM-MMIMO with PLNC surpassed that of a similar system without polar code (antenna elements used in the base station are 128 and 256). © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2023.

A new upgrade to the SIM–OFDM is suggested to solve a critical problem that crashes the system even over noiseless channel. This problem is the interference of the zeros at the IFFT output with the BOOK’s zeros that confuses the receiver during demodulation which leads to BER accumulation. The suggested solution is to use a threshold to differentiate the data carried by the BOOK from the IFFT’s symbols. The new system is called Threshold SIM–OFDM (TSIM–OFDM). The mathematical analysis of TSIM–OFDM proves it operates normally and meets the theoretical bounds. The TSIM–OFDM preserves the probability of 1 equal to ½. This preservation comes from the direct connection of the ON/OFF switching bits to the subcarrier which overrides the majority condition. This new switching technique simplifies the system operation resulting in higher transmission speed and increased spectral and power efficiency. A simple approach to derive the BER for the SIM– OFDM is presented which proves that the SIM–OFDM will never reach zero BER level unlike the TSIM–OFDM. The simulation results show that the TSIM–OFDM BER reaches zero level and the output power is almost half of the OFDM. Adding the threshold will increase the transmitted power slightly and tends to decrease with the increase of IFFT length. © 2023, Croatian Communications and Information Society. All rights reserved.