IEEE Open Journal of the Communications Society最新文献

{"title":"Optimal ACL Policy Placement in Hybrid SDN Networks: A Reinforcement Learning Approach","authors":"Wajid Ullah Khan;Nadir Shah;Gabriel-Miro Muntean;Haleem Farman;Moustafa M. Nasralla;Shan Ullah;Muhammad Shabir","doi":"10.1109/OJCOMS.2025.3589621","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3589621","url":null,"abstract":"The immediate transition to a fully Software-Defined Networking (SDN)-based architecture is both costly and operationally complex. As an alternative, a hybrid SDN architecture is introduced, where SDN-enabled devices are incrementally deployed alongside legacy network devices. This coexistence, however, presents significant challenges in network management and control, particularly in the efficient implementation of Access Control List (ACL) policies. ACL policies play a crucial role in defining network security and control mechanisms, yet existing approaches assume that all subnets affected by these policies are continuously transmitting data. Given the dynamic nature of subnet behavior, such static assumptions can lead to suboptimal network performance. To address this limitation, this paper proposes a novel Q-learning-based approach for dynamically deploying ACL policies based on real-time data transmission patterns of subnets. The proposed algorithm optimally determines the placement of ACL policies, minimizing both the total number of policies and redundant transmissions in the network. Extensive evaluations using real-world network traces and topologies demonstrate that our approach outperforms existing state-of-the-art methods in terms of efficiency and network performance.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"6095-6113"},"PeriodicalIF":6.3,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11082317","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144782050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vertical Handover Analysis Based on Cell Sojourn Distance: A Probabilistic Approach Inspired by Bertrand’s Paradox","authors":"Kenta Fukuhara;Sumiko Miyata;Masaki Aida","doi":"10.1109/OJCOMS.2025.3589153","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3589153","url":null,"abstract":"The recent surge in traffic demand has accelerated the development of heterogeneous highdensity networks. Consequently, the number of base stations has increased, leading to a rise in the frequency of vertical handovers between heterogeneous base stations, which results in delays and increased power wastage. Earlier studies analyzed the number of vertical handovers in such networks. However, previous studies have primarily focused on analyzing the frequency of vertical handovers, without addressing the distribution of sojourn time or utilizing it in the handover decision process. This paper analyzes vertical handover with direct consideration of the short cell sojourn time distribution as derived from stochastic geometry. Additionally, by referencing Bertrand's paradox, we define and simulate randomness in three different scenarios to validate our findings.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"6066-6077"},"PeriodicalIF":6.3,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11080307","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144782049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Robust Beamforming for Superdirective Antenna Arrays and Experimental Validations","authors":"Mengying Gao;Haifan Yin;Liangcheng Han;Jingcheng Xie","doi":"10.1109/OJCOMS.2025.3589033","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3589033","url":null,"abstract":"Superdirective antenna arrays have the potential to increase array directivity proportional to the square of the number of antenna elements. However, the high sensitivity problem of superdirectivity has posed a major challenge for practical applications. To address this issue, we propose a robust superdirective beamforming method that accounts for mutual coupling between antenna elements. We first introduce a universal sensitivity measurement applicable to coupled arrays and derive its closed-form expression, termed the degree of sensitivity (DoS). A beamforming optimization problem is then formulated to maximize the directivity factor while satisfying a DoS constraint, resulting in a parameterized beamformer where the parameter is difficult to determine. To solve this optimization problem, we propose an efficient orthogonal complement-aided quadratic constraint least squares (OC-QCLS) algorithm, which achieves the maximum possible directivity under the sensitivity constraint. Specifically, the framework of the least squares problem with a quadratic constraint is utilized to provide useful insights, and the intractable secular equation for the parameter is transformed into an easy-to-solve polynomial equation using the orthogonal complement. Numerical and electromagnetic (EM) simulations verify the effectiveness of the DoS and the OC-QCLS algorithm. The improvement in communication performance achieved by the OC-QCLS algorithm is demonstrated through its superior average spectral efficiency. Furthermore, an eight-dipole superdirective antenna array prototype with 0.20λ element spacing operating at 1.6 GHz is built, and real-world experiments validate the proposed method. Notably, the distributions of directivity metrics are analyzed and demonstrated in both simulation and experimental results.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"6005-6018"},"PeriodicalIF":6.3,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11079949","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144763685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IRS-Assisted Wireless Sensor Networks With Hybrid TDMA-NOMA","authors":"Haitham Al-Obiedollah;Haythem Bany Salameh;Kanapathippillai Cumanan","doi":"10.1109/OJCOMS.2025.3588440","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3588440","url":null,"abstract":"This paper investigates the energy harvesting (EH) and information decoding (ID) capabilities of wireless sensor networks (WSN) employing a hybrid time division multiple access (TDMA) and non-orthogonal multiple access (NOMA), i.e., the WSN with a hybrid TDMA-NOMA system. The system is assisted by a set of intelligent reflecting surface (IRS) units. In this configuration, the sensors are divided into a set of clusters, with each cluster consisting of two sensors. The available transmission time is equally divided into two phases: the downlink and uplink phases. In the downlink phase, the downlink time slot is dynamically split between the clusters into sub-time slots, where each sub-time slot is further divided into two slots, namely the wireless information transfer (WIT) and the wireless energy transfer (WET) slots. In the WIT slot, the sensors in the clusters use the received signal for ID, while the WET time slot is reserved for EH. However, in the uplink phase, the uplink time slot is also dynamically split into a set of slots, where each time slot is dedicated to assisting the uplink transmission from the sensors in each cluster to the base station (BS). To demonstrate the performance of such a system, we formulate a resource allocation framework that aims to minimize the total transmit power in the system while meeting a set of quality of service (QoS) requirements. Specifically, the total transmit power accounts for the downlink and uplink power, while the QoS requirements include a pre-defined minimum downlink data rate, minimum harvested energy for each sensor in the system, and minimum uplink data rate requirements. However, the joint nature of the optimization parameters in the downlink and uplink phases, namely power allocations in the downlink and uplink, time durations, and phase shift reflecting coefficients of the IRS units, as well as the non-convexity of the problem, introduces additional challenges in solving the formulated power minimization problem. To overcome these challenges, an iterative algorithm is proposed to solve the formulated optimization problem. To demonstrate the potential benefits of the proposed configuration, we present a set of simulations that evaluate its performance against two benchmarks: the IRS-free hybrid TDMA-NOMA system and the IRS-assisted hybrid TDMA-NOMA system with equal time allocations.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"6451-6462"},"PeriodicalIF":6.3,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11078432","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144896773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the Potentials of Narrowband Internet of Things (NB-IoT) Cellular Technology: Salient Features, Architecture, Smart Applications and Quality of Service (QoS) Challenges","authors":"Muhammad Waseem;Alicia Lopez;Pedro Luis Carro;Maria Angeles Losada;Dwight Richards;Abdul Aziz","doi":"10.1109/OJCOMS.2025.3588334","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3588334","url":null,"abstract":"Since the last decade, the number of Internet of Things (IoT) devices has increased dramatically and to operate them at low power has been a great challenge. Therefore, significant efforts have been made by the researchers to innovate such technologies that may operate the IoT devices at low power. In this context, several Low Power Wide Area Network (LPWAN) technologies have been introduced which have revolutionized the world of IoT. Narrowband Internet of Things (NB-IoT) is one of the protocols that was developed by 3rd Generation Partnership Project (3GPP) in June 2016 to cater the stringent requirements of IoT devices. In this paper, a comprehensive analysis on the features, architecture, signals and channels of NB-IoT is provided. Additionally, a detailed description of the applications of NB-IoT is also presented. Finally, some crucial challenges related to the quality of service (QoS) of NB-IoT are highlighted in this paper.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"6258-6280"},"PeriodicalIF":6.3,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11078419","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144896774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An ISAC-Assisted Beam Alignment Design for HAP-Based 6G Flying Ad-Hoc Networks","authors":"Muhammet Kirik;Liza Afeef;Hüseyin Arslan","doi":"10.1109/OJCOMS.2025.3586964","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3586964","url":null,"abstract":"High altitude platforms (HAPs) can establish autonomous airborne networks, known as flying ad-hoc networks (FANETs), without relying on terrestrial infrastructure. A crucial aspect of these networks is maintaining robust links between HAPs, achievable through advanced multiple input multiple output (MIMO) techniques like beamforming. However, the unpredictable motion of HAPs necessitates frequent beam alignment. This paper proposes a novel two-step beam alignment method for inter-HAPs networks, leveraging the integrated sensing and communication (ISAC) concept. The first step involves a coarse beam alignment using sensing and triggering signals to extract channel parameters and activate a targeted HAP at low frequency bands. In the second step, a fine beam alignment is performed at high frequency bands to enhance the link connection within the narrowed area defined in the first step. Utilizing an antenna activation controller, the proposed method efficiently uses a single antenna array for dual-purpose signals across different frequency bands, reducing deployment costs and enhancing system efficiency. Mathematical analysis and numerical results demonstrate that this method significantly improves system performance by reducing alignment time overhead, while maintaining high communication capacity, beamforming gain, and detection rates for targeted HAPs.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"5923-5939"},"PeriodicalIF":6.3,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11075863","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144725117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HAPS-ISAC: Enhancing Sensing and Communication in 6G Networks With Advanced MIMO Beamforming","authors":"Parisa Kanani;Mohammad Javad Omidi;Mahmoud Modarres-Hashemi;Halim Yanikomeroglu","doi":"10.1109/OJCOMS.2025.3587077","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3587077","url":null,"abstract":"This paper introduces a novel high altitude platform station (HAPS)-based integrated sensing and communication (ISAC) system, referred to as HAPS-ISAC, designed to enhance the capabilities of future 6G networks by simultaneously optimizing communication and sensing functions. HAPS operates as a super-macro base station in the stratosphere, utilizing advanced beamforming techniques within a multiple-input multiple-output (MIMO) architecture, supplemented by multiple-input single-output (MISO) configurations, effectively enabling the system to serve ground communication users (CUs) while conducting high-resolution sensing of potential targets. A Rician channel model is employed to capture both line-of-sight (LoS) and non-line-of-sight (NLoS) conditions. The performance of the system is optimized through a non-convex optimization problem that maximizes the minimum beampattern gain towards desired sensing angles while ensuring that the signal-to-interference-plus-noise ratio (SINR) requirements for CUs are satisfied, all under the power constraints of the HAPS. Compared to the traditional terrestrial and UAV-based ISAC systems, HAPS-ISAC delivers sustained and reliable service over extensive areas, leading to significantly improved overall performance. Simulation results show that HAPS-ISAC significantly improves SINR, resource allocation, sensing accuracy, and fairness, outperforming existing technologies. This establishes HAPS-ISAC as a key enabler for 6G networks and advances intelligent infrastructures like IoT and smart cities.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"5988-6004"},"PeriodicalIF":6.3,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11075820","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144764087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Link-Level Evaluation of Uplink Cell-Free MIMO in 5G NR Over Frequency-Selective Channels","authors":"Mostafa Rahmani Ghourtani;Junbo Zhao;Yi Chu;Hamed Ahmadi;David Grace;Robert G. Maunder;Alister Burr","doi":"10.1109/OJCOMS.2025.3587990","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3587990","url":null,"abstract":"Cell-free (CF) MIMO has emerged as a promising next-generation technology, primarily due to its ability to provide uniformly high-quality service to all user equipment (UEs), regardless of their location. While existing research has extensively explored various aspects of CF systems–including scalability, clustering strategies, power control, and precoding designs–there remains a notable gap in the literature concerning the physical-layer performance of 5G New Radio (NR) within CF architectures. This paper addresses this gap by focusing on the Physical Uplink Shared Channel (PUSCH) transmission over frequency-selective channels. We develop a comprehensive, 3GPP-compliant link-level simulator to evaluate the performance of CF MIMO under realistic propagation conditions. First, we generate results for selected modulation and coding schemes (MCSs) to confirm the simulator’s alignment with expected performance. Then, the effects of key physical-layer parameters–such as subcarrier spacing (SCS), the number of distributed radio units (RUs), and the number of RU antennas–are evaluated using Block Error Rate (BLER) as the primary performance metric. We also compare the results of the CF-MIMO system with a co-located antenna scenario, serving as the baseline for a traditional MIMO system, and confirm that the CF-MIMO system achieves superior performance due to its spatial diversity advantages. The results also show that employing higher SCS values effectively exploits frequency diversity, particularly when the signal bandwidth exceeds the channel’s coherence bandwidth. As expected, increasing the number of RUs significantly improves BLER due to enhanced spatial diversity and reduced UE-RU path loss. We further examine the impact of practical channel estimation by evaluating four different DMRS configurations, confirming that Type 1 with length 2 provides superior performance under the tested conditions. Finally, we investigate the effect of carrier frequency, showing that higher frequencies lead to increased path loss and degraded performance. The findings offer valuable insights into spatial, frequency, and estimation-related interactions in CF 5G NR, while guiding MCS selection for target BLER-SNR levels and enabling PHY abstraction for higher-layer simulations.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"5903-5922"},"PeriodicalIF":6.3,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11077661","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144725164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"5G-NR Over Transparent Payload GEO Satellites: A Hands-On Approach Using OpenAirInterface5G-NTN","authors":"Sumit Kumar;Jevgenij Krivochiza;Turker Yilmaz;Jorge Querol;Symeon Chatzinotas;Stefano Andrenacci;Joel Grotz","doi":"10.1109/OJCOMS.2025.3586871","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3586871","url":null,"abstract":"The inclusion of Non-Terrestrial Network (NTN) components has significantly enhanced the reach of 5G networks. OpenAirInterface5G (OAI) has developed an open-source, Software-Defined Radio (SDR)-based framework for 5G-NTN, using its Terrestrial Network (TN) protocol stack as the baseline. OAI’s 5G-NTN adaptations are still evolving, requiring in-lab validations and field trials to assess its effectiveness in addressing the unique challenges of NTN components and channel characteristics. Live satellite tests, unlike simulations, demand manual tuning of key parameters like carrier frequency offset, timing offsets, and gain calibration. In this work, we present a practical approach for deploying 5G over GEO satellites using the OAI 5G-NTN suite, addressing (a) satellite channel impairments and (b) limitations in OAI’s current 5G-NTN implementation. Our work provides step-by-step calibrations, ensuring both experiment reproducibility and the realization of a full 5G-NTN link. We further identify the performance bottlenecks and experiment with (a) Radio Link Control Acknowledgment Mode (RLC-AM) parameters and (b) Low-Density Parity Check (LDPC) iterations to improve end-to-end throughput. We validate our methods via live tests over a transparent payload GEO satellite. We believe that our work represents a critical step in bridging the gap between lab-based 5G-NTN emulation and live satellite testing, offering valuable insights to advance 5G-NTN research and development.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"5969-5987"},"PeriodicalIF":6.3,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11073184","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Filtered Multi-Tone Spread Spectrum With Overlapping Subbands","authors":"Brian Nelson;Hussein Moradi;Behrouz Farhang-Boroujeny","doi":"10.1109/OJCOMS.2025.3586206","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3586206","url":null,"abstract":"A new form of the filter bank multi-carrier spread spectrum (FBMC-SS) waveform is presented. This new waveform modifies the filtered multi-tone spread spectrum (FMT-SS) system, and is intended to whiten the power spectral density (PSD) of the transmit signal. In the conventional FMT-SS, subcarrier bands are non-overlapping, leaving a spectral null between the adjacent subcarrier bands. To make FMT-SS more appealing for a broader set of applications than those studied in the past, we propose adding additional subcarriers centered at these nulls and thoroughly explore the impact of the added subcarriers on the system performance. This modified form of FMT-SS is referred to as overlapped FMT-SS (OFMT-SS). We explore the conditions required for maximally flattening the PSD of the synthesized OFMT-SS signal and for cancelling the interference caused by overlapping subbands. We also explore the choices of spreading gains that result in a low peak-to-average power ratio (PAPR) for a number of different scenarios. Further reduction of the PAPR of the synthesized signal through clipping methods is also explored. Additionally, we propose methods of multi-coding for increasing the data rate of the OFMT-SS waveform, while minimally impacting its PAPR.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"5712-5726"},"PeriodicalIF":6.3,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11073810","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144671209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}