Wireless Channel Research Articles

Factors Influencing Learners Discontinuation in the Alternative Learning System

This study looked into identified reasons for enrolling in the Alternative Learning System to determine what factors lead to ALS learners dropping out of the program. This study utilized a descriptive correlational design employing a researcher-made survey to gather data. The survey underwent validation by three experts in the field of research and Alternative Learning Systems and passed the validity test conducted. The responses of the participants were analyzed to determine if there is a significant difference in their profiles based on the reasons, they reported for enrolling in ALS using the ANOVA test. The investigation also looked into whether there is a correlation between the reasons reported by the participants for enrolling in ALS and the factors affecting their discontinuation. It was found that there is no significant difference in the profiles of the respondents such as age, gender, civil status, level taken, and monthly income in the reasons they reported for enrolling in ALS. However, it was discovered that there is a significant correlation between the reasons reported by the students for enrolling in ALS and the factors influencing their discontinuation. In response to the challenge of student discontinuation, it is proposed to initiate and effectively implement Radio-Based Instruction (RBI) as an alternative mode of delivery for ALS programs. Leveraging radio broadcasting, this innovative approach to distance learning has the potential to significantly enhance access to education by reaching students in diverse geographic locations, thereby mitigating the barriers posed by distance and geographical isolation. Moreover, RBI allows learners the flexibility to engage in their studies even while occupied with other activities, further facilitating their educational journey. Keywords: Alternative Learning System, Influencing Factors, Learners Discontinuation, ALS Learners

Mathematical Model of the Process of Data Transmission over the Radio Channel of Cyber-Physical Systems

This article introduces a refined mathematical model to evaluate the quality of mobile radio channels within cyber-physical systems, employing the topological transformation of stochastic networks. The operation of the radio channel is conceptualized as a stochastic network, enabling the derivation of critical metrics such as an equivalent function, mathematical expectation, variance, and the time distribution function of the implemented processes. The model uses the Gamma distribution for the initial distribution functions of random variables, enhancing its analytical precision. A significant advancement of this study is the development of a comprehensive model that describes the data transmission process through phases of connection establishment, information transmission, and connection maintenance. The innovative aspect of this research lies in applying an equivalent function to a stochastic network that includes a logical “AND” node with gamma-distributed incoming branches. The stochastic network presented in the article, which includes a logical “AND” node, helps to elucidate the mechanism for obtaining an equivalent function for such networks, allowing the application area of the GERT method to be expanded. This methodological enhancement extends the previously limited scope of topological transformation methods, which only applied to exponential distribution models for the timing of branch inputs. By integrating a Gamma distribution, the model simplifies the equivalent function and reduces the computational complexity required to assess the radio channel’s quality, ensuring the accuracy needed for engineering calculations. Moreover, the proposed method requires 25–40% fewer series members than the traditional Taylor series decomposition, while maintaining comparable computational complexity for the typical series members. Furthermore, the maximum absolute error in the calculations is capped at 9 × 10−3, which is well within acceptable limits for engineering purposes. Primarily designed for radio channels in cyber-physical systems, the model’s applicability extends to wireless communications, providing a valuable tool for evaluating channel efficiency and security in the face of increasing cyber threats.

UAV-Mounted RIS-Aided Mobile Edge Computing System: A DDQN-Based Optimization Approach

Unmanned aerial vehicles (UAVs) and reconfigurable intelligent surfaces (RISs) are increasingly employed in mobile edge computing (MEC) systems to flexibly modify the signal transmission environment. This is achieved through the active manipulation of the wireless channel facilitated by the mobile deployment of UAVs and the intelligent reflection of signals by RISs. However, these technologies are subject to inherent limitations such as the restricted range of UAVs and limited RIS coverage, which hinder their broader application. The integration of UAVs and RISs into UAV–RIS schemes presents a promising approach to surmounting these limitations by leveraging the strengths of both technologies. Motivated by the above observations, we contemplate a novel UAV–RIS-aided MEC system, wherein UAV–RIS plays a pivotal role in facilitating communication between terrestrial vehicle users and MEC servers. To address this challenging non-convex problem, we propose an energy-constrained approach to maximize the system’s energy efficiency based on a double-deep Q-network (DDQN), which is employed to realize joint control of the UAVs, passive beamforming, and resource allocation for MEC. Numerical results demonstrate that the proposed optimization scheme significantly enhances the system efficiency of the UAV–RIS-aided time division multiple access (TDMA) network.

Hybrid Multiple Access Techniques Performance Analysis Of Dynamic Resource Allocation

The Non-Orthogonal Multiple Access (NOMA) and the Orthogonal Frequency Division Multiple Access (OFDMA) are promising techniques for next-generation wireless systems. Although much attention in the literature considered these techniques, an effective combination between such systems as hybrid multiple access (HMA) needs more attention. For this reason, this paper devotes to proposing two different scenarios of HMA using multi-user OFDM (MU-OFDM) and power domain (PD) NOMA for downlink transmission to overcome the limitations of both Orthogonal Multiple Access (OMA) and NOMA. Due to the randomness of a wireless channel, different user grouping strategies and dynamic power allocation (DPA) strategies are employed to satisfy users’ requirements. The proposed systems give high flexibility utilizing bitrate allocation and user fairness. System results show superior performance to traditional OMA and NOMA systems. The achieved variety of fairness is helpful for the diversity of applications which is a principal requirement for beyond-fifth-generation (B5G) networks. The next step in this analysis is to enhance the proposed systems’ spectral efficiency (SE) by introducing beamforming for massive Multiple-Input Multiple-Output (MIMO) systems. The bit error rate (BER) result of the proposed system achieves almost the same error floor with a benefit of approximately 10 dB signalto-noise ratio (SNR) when 90 resource blocks (RBs) are used.  

Artificial Broadcasts as Galactic Populations. II. Comparing Individualist and Collective Bounds on Broadcast Populations in Single Galaxies

The search for extraterrestrial intelligence includes efforts to constrain populations of artificial broadcasts in other galaxies. Previous efforts use individualist methods, searching for single broadcasts with high signal-to-noise ratio. These would be detected as observables with extreme values. This approach is limited to very bright broadcasts and also is subject to confusion, where a large number of broadcasts blend together to form a noise continuum. The mean value of the total emission provides an additional collective bound: the luminosity of the transmitters is no higher than the galaxy’s observed luminosity. Using the framework developed in Paper I, I evaluate how confusion affects individualist searches. I then compare individualist and collective approaches for radio broadcasts from the Milky Way, M31, and three Virgo Cluster elliptical galaxies. For current observations, confusion blurs narrowband radio broadcasts together in the Virgo ellipticals when there is one broadcast per gigahertz per 1000 stars. The collective bound implies fewer than ∼106(ℓ¯/1013W)−1 L-band broadcasts per star per gigahertz in the Milky Way wideband and is about 10 and 400 times stronger in M31 and M59, respectively. Applying the collective bound to the far-infrared–radio correlation yields constraints on radio broadcast populations in star-forming galaxies throughout the Universe. The collective bound allows us to rule out large regions of broadcast population parameter space even for distant galaxies. It also imposes constraints on gamma-ray, neutrino, and gravitational-wave broadcasts in the nearest galaxies.

Analyzing the blockchain mining strategy in Industrial Internet of Things: A game theoretical approach

Deploying Proof-of-Work (PoW) consensus based blockchain systems in Industrial Internet of Things (IIoT) scenarios that rely on wireless channels for data transmission faces new challenges. An IIoT device working in industrial production may participate in the operation of blockchain as a miner. These devices not only need to consume their own computation capability to compete for the right to generate blocks, but also need to transmit newly generated blocks to other devices through wireless channel to continuously maintain the global ledger. Asynchronous mining and data transmission by IIoT devices in wireless environments may significantly interfere with the propagation of blocks in the system and result the reduction of mining payoff, thereby affecting the willingness of IIoT devices to participate in maintaining blockchain system. This paper considers the behavior of independent mining between multiple IIoT devices as a non-cooperative game, which we call the Wireless Mining Game (WMG). Markov chain is adopted to derive the block propagation model under the wireless channel, and then the payoff model of IIoT device is formulated. IIoT devices can make reasonable mining decisions by evaluating the computation capability of other IIoT devices and the probability of successful block transmission. We analyze the Nash equilibrium of the WMG and the corresponding mining behavior set between two-players scenario through theoretical modeling and experiments. We also analyzed the expected mining payoff of the IIoT devices in the multiple devices scenario.

Energy-efficient Mobile Edge Computing Assisted by Layered UAVs Based on Convex Optimization

The utilization of unmanned aerial vehicles (UAVs) as aerial mobile edge computing (MEC) servers presents an effective approach for mitigating the computational limitations of intelligent mobile devices. However, the limited battery capacity of UAVs poses a significant challenge in ensuring sustained service provision. To counter this obstacle and enhance energy efficiency, we introduce a partial offloading MEC scheme assisted by layered UAVs (POAL). Our objective is to minimize the total energy consumption of UAVs by jointly optimizing several factors, including wireless channels, transmit power, task partition, computing power, and UAV trajectories. Due to the non-convexity of the problem, we decompose it into three sub-problems and address them iteratively. Firstly, we employ the CVX optimization tool to allocate wireless channels and utilize Lagrangian duality to determine the optimal transmit power. Secondly, leveraging the monotonicity of the optimization objective, we derive the optimal computing power. Lastly, we employ the successive convex approximation (SCA) technique to tackle the trajectory planning sub-problem. Numerical results demonstrate that our proposed algorithm can effectively position UAVs within 15 iterations. Furthermore, our layered scheme significantly reduces overall energy consumption.

Comparative analysis of coding schemes for effective wireless communication

Communication systems have recently focused on sending information efficiently and effectively from one sending point to another across a communication channel in the shortest amount of time. The main objective of this work is to compare the high-range coding scheme types, such as low density parity check (LDPC), turbo, and convolution, to see which works better and is more efficient. to establish a coding system with quadrature amplitude modulation (QAM) modulation and an additive white gaussian noise (AWGN) noisy channel to find which is more reliable and resilient for encoding and decoding. Because of this, digital media has to be sent over wireless channels and through satellites, requiring a connected network all the time, which has become a major concern over time. Furthermore, the high amount of data and efficiency are the focus points. After running the simulation, it was found that 64 QAM with a rate of 0.455 and an efficiency of 2.731 has a bit error rate (BER) of 0.001 and a 7.08 dB energy per bit Eb/No, and the 256 QAM simulation revealed that it has a BER of 0.001 and 11.88 dB Eb/No with a rate of 0.736 and an efficiency of 5.891. Over the AWGN channel noise, the simulation built a standard orthogonal frequency division multiplexing (OFDM) system, which used MATLAB.

A Security-Enhanced Authentication Scheme for Quantum-Key-Distribution (QKD) Enabled Internet of Vehicles in Multi-Cloud Environment

The Internet of vehicles (IoV) is an essential part of modern intelligent transportation systems (ITS). In the ITS, intelligent connected vehicle can access a variety of latency-sensitive cloud services through the vulnerable wireless communication channel, which could lead to security and privacy issues. To prevent access by malicious nodes, a large number of authentication schemes have been proposed. However, with the diversification of cloud services and the rapid development of quantum computing, there are many drawbacks remain, including timeliness of authentication and resisting quantum computing. In light of this, we propose a lattice-based secure and efficient multi-cloud authentication and key agreement scheme for quantum key distribution (QKD) enabled IoV. Its features are as follows: i) Security-enhanced and Efficient Authentication: We combine the lattice-based lightweight signatures and quantum authentication keys to guarantee security-enhanced authentication. Meanwhile, we propose the quantum security service cloud (QSC) to manage the authentication of all vehicles and cloud server providers (CSPs) to reduce the authentication rounds and improve efficiency. ii) Extended Quantum Key Distribution (eQKD): In wireless networks, quantum key agreement is achieved through the pre-filled quantum keys. In wired networks, quantum key is accomplished by QKD with Bennett-Brassard 1984 (BB84) protocol. Furthermore, formal and informal security demonstrates that the scheme could resist potential security attacks. The performance comparison illustrates that our scheme could decrease the computational overhead by 27.23%-81.78% and authentication rounds by 81.34%-93.10%.

Federated Learning With Dynamic Epoch Adjustment and Collaborative Training in Mobile Edge Computing

As a distributed learning paradigm, federated learning (FL) can be applied in mobile edge computing (MEC) to support real-time artificial intelligence by leveraging edge computation resources while preserving data privacy in the end devices. However, the unpredictable wireless connections between end devices and edge servers in MEC (e.g., frequent handovers and unstable wireless channels) may result in the loss of important model parameters, which slows down the FL training process and degrades the quality of the global model. In this paper, we propose an adaptive collaborative federated learning (ACFL) scheme to accelerate the convergence and improve model reliability by mitigating communication-based parameter loss under a three-layer MEC architecture. Firstly, a dynamic epoch adjustment method is proposed to reduce communication rounds by dynamically adjusting the training epochs in end devices. In addition, to accelerate the FL convergence, we present an edge server collaborative training scheme by leveraging a multi-layer computing architecture, where edge servers utilize their maintained data to collaboratively train models with end devices. Finally, extensive simulations are conducted and show that ACFL can efficiently improve model reliability and accelerate the convergence of the FL process in MEC.

Wireless Channel Characterization From 2 to 28 GHz in an Outdoor Parking Lot

Wireless Channel Characterization From 2 to 28 GHz in an Outdoor Parking Lot

Learning-Based Autonomous Channel Access in the Presence of Hidden Terminals

We consider the problem of autonomous channel access (AutoCA), where a group of terminals tries to discover a communication strategy with an access point (AP) via a common wireless channel in a distributed fashion. Due to the irregular topology and the limited communication range of terminals, a practical challenge for AutoCA is the hidden terminal problem, which is notorious in wireless networks for deteriorating throughput and delay performances. To meet the challenge, this paper presents a new multi-agent deep reinforcement learning paradigm, dubbed MADRL-HT, tailored for AutoCA in the presence of hidden terminals. MADRL-HT exploits topological insights and transforms the observation space of each terminal into a scalable form independent of the number of terminals. To compensate for the partial observability, we put forth a look-back mechanism such that the terminals can infer behaviors of their hidden terminals from the carrier-sensed channel states as well as feedback from the AP. A window-based global reward function is proposed, whereby the terminals are instructed to maximize the system throughput while balancing the terminals' transmission opportunities over the course of learning. Considering short-packet machine-type communications, extensive numerical experiments verified the superior performance of our solution benchmarked against the legacy carrier-sense multiple access with collision avoidance (CSMA/CA) protocol.

Pediatric COVID-19 Response in the Philippines

The COVID-19 pandemic has been an unprecedented global health crisis, affecting individuals of all ages. In thePhilippines, as we continue to combat the virus, we put focus on one particularly vulnerable group: our children.1 As weconfront the complexities of pediatric COVID-19 management, we provide insight into the response strategies establishedto protect the health of our youngest population. At the beginning of the pandemic, the Philippines undertook a comprehensive approach that encompassed travel restrictions,community interventions, robust risk communication, and rigorous testing procedures. These measures were implementedwith the overarching goal of mitigating the impact of COVID-19 and safeguarding the nation’s healthcare system.2 On March 30, 2020, the Philippine General Hospital (PGH) officially became the COVID-19 Referral Center inthe country. It has been more than four years since that fateful day when we had to brace ourselves for what was about tohappen. All of the departments, including the pediatrics department, had risen to the challenge with change in infrastructure,creation of clinical guidelines for COVID-19 management, formulation of infection control measures, and allocation ofprotective equipment and training for health workers.3 The PGH Transfer Command Center (TCC) was in-charge of triaging, decking, and admitting patients to thehospital.3 During the surges, the TCC was besieged with calls from desperate doctors and relatives with COVID-19 ofvarying severity – critical, severe, moderate, mild, and asymptomatic. Several projects and programs have sprung to help withthe pandemic. An algorithm was created at the time by the Class of 1991 UP College of Medicine, which was a quick,simple, complete, easy-to-understand guideline which navigate patients in their homes.4,5 Through a number of medicalprofessional volunteers, the Philippine General Hospital (PGH) COVID Gabay Program was launched to guide families via ateleconsultation platform.6 A community preventive approach included the promotion of mask-wearing, physical distancing, and hand hygiene,aligning with recommendations from global health organizations like the World Health Organization (WHO) andthe Centers for Disease Control and Prevention (CDC).7,8 Locally, the Philippine Pediatric Society has issued a parentsCOVID-19 prevention guide to disease prevention, symptoms, home care, and breastfeeding9, and treatment guidelinesregarding the disease in children were formulated by the Pediatric Infectious Disease Society to be used by the communityand pediatricians10. Initially, COVID-19 vaccines in the Philippines were primarily administered to adults. The vaccination campaigntargeted healthcare workers, senior citizens, and individuals with comorbidities, as well as its level of acceptability in thecommunity.11 The eligibility for pediatric vaccination depended on regulatory approvals and vaccine availability then. Currently,the vaccination program has expanded to include younger age groups along with COVID-19 booster doses. However,vaccine hesitancy especially by the parents has been a challenge brought about by different factors such as exposure to falseinformation amplified by the media, the community, and the health system.12,13 The disruptions caused by the COVID-19 pandemic in the education sector have had profound effects on childrenas Philippines had one of the longest lockdown period worldwide.14 As education was reinstated in October 2020, theeducation department’s approach was a combination of remote learning alternatives, including online platforms, educationaltelevision and radio broadcasts, and printed study materials. However, the significant challenge lies in the disparities insocial circumstances and the absence of adequate resources at home, which has adversely affected numerous students andeducators.14,15 The apprehension and worry about contracting the virus, the cessation of in-person classes, the disturbance of theirusual daily routines, and the reduction in social interactions with schoolmates all contribute to an increased strain on themental health of children.16 In anticipation of the mental health challenges at the pandemic’s outset, the PsychologicalAssociation of the Philippines compiled a roster of complimentary telemedicine consultations. Furthermore, the PhilippineRed Cross initiated a COVID-19 hotline to attend to mental health issues and related concerns. Additionally, theDepartment of Health has launched nationwide campaigns during the National Mental Health Week.17 Our commitment to the well-being of our children during this pandemic is a reflection of our society’s resilience andcompassion. By addressing these challenges and implementing solutions, we can protect the future of our nation. In conclusion, the pediatric COVID-19 response in the Philippines is a critical endeavor that demands our collective effort.We must prioritize the health, education, and emotional well-being of our children as we navigate these challenging times.Let us work together to ensure that no child is left behind in our journey towards a safer and healthier future.  

Patch-based Reversible Steganography for Secured Communication over Wireless Channels

Securing the perceptual quality of the cover image (CI) and acquiring higher security for hidden information in stego images (STIs) are two sides of the same coin. There is always a trade-off between perceptual quality and level of security when secret bits (SBs) of the secret image (SI) are embedded in a CI. Non-reversible techniques are adopted where a higher level of security is required as in communication, while reversible schemes are preferred to maintain the visual quality of the CI. This article proposes a novel Patch-Based LSB Embedding (LSBE) Data Hiding (PB-LSB-EDH) scheme that provides better security to SBs and maintains stego quality. The scheme embeds a secret byte in a 3x3 patch of the CI. The starting byte in the neighborhood where the SBs are hidden is computed from the center pixels of the 3x3 patch window and continues to embed pixels clockwise.  The PB-LSB-DH scheme is highly immune to external noise or attacks when the intensity value of the center pixels is equal to or greater than 12 since the starting index of bit embedding is computed using a natural logarithm. Experimental analysis of four different CIs and SIs showed that the proposed PB-LSB-DH scheme maintains the better perceptual quality of the CI and a higher peak signal-to-noise ratio (PSNR) above 50.

Обеспечение радиопокрытия прибрежной морской зоны с применением беспроводного широкополосного оптического канала для организации интенсивного судоходства

The model of a wireless broadband optical channel designed for communication between the coastal subsystem and an air repeater that provides coverage of the coastal sea area for the organization of intensive navigation, including the use of unmanned vessels is presented. It is shown that direct coast-to-ship data transmission using Wi-Fi and 4G/LTE technologies has a number of disadvantages for bays with complex coastal terrain. The use of a wireless optical channel in the "point-to-point" format between the coastal subsystem and the air transmitter makes it possible to provide high-quality radio coverage of the sea surface and provide information-intensive channels to ship systems. The results of modeling the wireless optical channel implemented using FSO (Free Space Optic) technology are presented. To increase the efficiency of using the spectrum of the transmitted data stream and the protection ratio of the wireless channel, 16QAM and OFDM are used.

WOMEN’S EMPOWERMENT THROUGH RADIO BROADCAST PROGRAM STRATEGY

The radio broadcasting strategy is carried out by Beautiful Radio 95.6 FM on the broadcast program Ruang Perempuan. This research aims to find out the process of radio broadcasting strategy with Ruang Perempuan program using the concept of Peter K Pringle. This research uses a qualitative approach with a case study research design. The technique of determining informants using purposive sampling technique. The research data obtained from observation, interviews, and documentation. The results of the research on the planning stage of Ruang Perempuan broadcasts are through the selection of themes, program formats, production teams and broadcasters, program objectives and routine evaluation. The production stage begins with making a question list, preparing equipment, making digital posters and brifieng; then followed by the production stage. The post-production stage involved handing over the inspirational women's charter and editing the aftermovie video. Execution stage by determining broadcast hours based on planning and target listeners. The monitoring and evaluation stage is carried out on an ongoing basis and once a month. Ruang Perempuan is present to optimize the broadcast program with the target audience of adult women aged 30-45 years in terms of information, inspiration, and motivation regarding finance, career, profession, business through female speakers. The implication is that radio broadcast programs specifically designed to encourage women's empowerment can be one of the effective instruments in overcoming gender inequality and increasing women's participation in various aspects of life.

Интеллектуальные метаповерхности, Фурье-оптика и криптография: новые научные горизонты

Reviews the current state of programmable and intelligent metasurfaces (MS) and their emerging applications in advanced integrated devices. For example, intelligent MS can adapt radio wave propagation channels and enhance their differences. The main strategies for designing intelligent MSs are considered. The necessity of combining such intelligent MSs with numerous methods of topological texture-fractal processing of signals and fields is revealed.

A novel swarm intelligence‐based fuzzy logic in efficient connectivity of vehicles

SummaryA vehicular ad hoc network (VANET) is a wireless network composed of a collection of mobility devices that link via a wireless channel without the need for permanent infrastructure or centralized administration. Multicasting is a method of sending data from a single node to multiple recipients at the same time. Because of its energizing network topology and constricted resources, a mobile ad hoc network (MANET) presents a number of issues. Because network execution measurements such as latency, bandwidth, throughput, and energy fluctuate so rapidly owing to node movement, these network properties in a wireless mobile ad hoc network are ambiguous. Because of the influence of these uncertainty issues, determining the top‐grade path from the originating node to a set of recipient nodes is challenging. In order to preserve network resources, we used a Swarm Intelligence‐based fuzzy logic strategy in this study that includes channel caliber factor and connection termination time to try to alleviate these uncertainty issues. This strategy integrates all of the network indicators available for the routes into an individual quantity named as fuzzy cost or cost of communication. The routes with the lowest fuzzy cost will be regarded optimum, and data will be delivered along this route from the originating point to a set of receivers. The simulation was carried out using NS‐3.38 and MATLAB, and the results reveal that the suggested protocol, HACOFLM, outperforms ODMRP, OFAODV, MAODV, and DFMCRP by means of packet delivery ratio, latency, control packet overhead, and throughput. DFMCRP outperforms MAODV by 3% to 6%, OFAODV by 13% to 19%, and ODMRP by 16% to 23%. According to HACOSMO, based on the number of vehicles and velocities, routing overhead is 7% to 10% less than DFMCRP, 9% to 13% less than MAODV, 17% to 29% less than OFAODV, and 22% to 36% less than ODMRP. It improvise throughput by 4% to 6% when contrasted to DFMCRP, 5% to 9% when contrasted to MAODV, 10% to 14% when contrasted to OFAODV, and 14% to 23% when contrasted to ODMRP.

Delay-sensitive task offloading and efficient resource allocation in intelligent edge–cloud environments: A discretized differential evolution-based approach

The number of smart wireless devices (WDs) has enormously increased over the last few years due to the advancement of 5G/B5G networks. The advanced applications of such smart WDs, e.g., augmented reality, virtual reality, online gaming, etc., demand excessive resources. Although the WDs are equipped with limited resources, the evolution of edge computing and offloading techniques enables the WDs to offload their resource-intensive tasks to the nearby edge node. These edge nodes might experience higher loads and delays when WDs generate a huge number of tasks. Moreover, the wireless channel bandwidth and transmission data rate of the wireless channels are also limited. Therefore, optimizing the use of available bandwidth as a valuable resource and reducing latency emerge as crucial objectives while offloading tasks. In this paper, a delay-aware resource-constrained offloading problem for edge–cloud systems is mathematically formulated as a 0–1 integer linear programming, and it is shown to be NP-complete. Then, a delay-aware resource-constrained offloading algorithm based on a discretized differential evolution (DARC-DE) is designed. The objectives of the DARC-DE are to maximize the utilization of the resources as bandwidth and minimize the delay. The vectors are efficiently encoded along with the decoding technique. The fitness function is designed by considering execution, offloading, queuing, transmission delay, and bandwidth utilization. The DARC-DE is shown to be executed in polynomial time. To evaluate DARC-DE, extensive simulation is performed in two different scenarios with varying numbers of tasks and edges. Simulation results demonstrate that the proposed DARC-DE can minimize total delay by 15% to 40% in comparison to particle swarm optimization, genetic algorithm, and bees algorithm, respectively. Simulation results also indicate a significant improvement in bandwidth utilization. Taguchi method and alternative average convergence rate are conducted. The statistical tests—analysis of variance, post-hoc, and Friedman tests—are also performed.

Miniaturized Microstrip Dual-Channel Diplexer Based on Modified Meander Line Resonators for Wireless and Computer Communication Technologies

There has been a lot of interest in microstrip diplexers lately due to their potential use in numerous wireless and computer communication technologies, including radio broadcasts, mobile phones, broadband wireless, and satellite-based communication systems. It can do this because it has a communication channel that can combine two distinct filters into one. This article presents a narrow-band microstrip diplexer that uses a stepped impedance resonator, a uniform impedance resonator, tiny square patches, and a meander line resonator. The projected diplexer might be made smaller than its initial dimensions by utilizing the winding construction. To model the microstrip diplexer topology for WiMAX and WIFI/WLAN at 1.66 GHz and 2.52 GHz, the Advanced Wave Research (AWR) solver was employed. It exhibited an insertion loss of 3.2 dB and a return loss of 16 dB for the first channel, while the insertion loss and return loss were 2.88 dB and 21 dB, respectively, for the second channel. When both filters were simulated, the band isolation was 31 dB. The projected microstrip diplexer has been fabricated using an FR4 epoxy laminate with dimensions of 32 × 26 mm2. The simulated S-parameters phase and group delay closely matched the measurements.