Maximum Communication Distance Research Articles

Single-Use Aircraft Launch System with Small Helium Balloon for 1 kPa Flight Testing

A single-use aircraft launch system using a small helium balloon concept was proposed to elevate the likelihood of successful high-altitude flight tests above 30 km. The system, capable of carrying a payload of 0.5 kg, has been developed and reported. Completing the flight within a range of 92 km, which represents the maximum communication distance between the airborne flight system and the ground station for operational phase control, is imperative. Therefore, a straightforward method for simulating flight trajectories was outlined to determine launch windows and suitable locations to ensure flight completion within uninhabited areas. Simulation studies revealed that the shortest landing distance was obtained during summer at the selected launch site. Additionally, a parameter study was conducted to assess the influence of varying ascent velocities on the targeted flight test altitude, which depends on the payload weight and helium gas volume. Consequently, the parameter study results established the constraints for flight model design. A demonstration flight was conducted in 2023 to validate the feasibility of the system for high-altitude flight experiments. This flight successfully released the flight model at 31 km and recovered flight data before landing on the sea surface. The proposed system concept offers an expedited approach to aircraft design for operating in thin air. It enables component function tests and scaled model flights as an alternative to employing large high-altitude balloons for high-altitude experiments.

ZEROES: Robust Derivative-Based Demodulation Method for Optical Camera Communication

Most of Optical Camera Communication (OCC) systems benefit from the rolling shutter mechanism of Complementary Metal-Oxide Semiconductor (CMOS) cameras to record the brightness evolution of the Light-Emitting Diode (LED) through dark and bright strips within images. While this technique enhances the maximum achievable data rate, the main difficulty lies in the demodulation of the signal extracted from images, subject to blooming effect. Thus, two main approaches were proposed to deal with this issue, using adaptive thresholds whose value evolves according to amplitude changes or detecting signal variations with the first-order derivative. As the second method is more robust, a new demodulation method based on the detection of the zeros of the first-order derivative of the extracted signal was proposed in this paper. Obtained results clearly show an improvement in the extracted signal demodulation compared to other methods, achieving a raw Bit Error Rate (BER) of 10−3 around 50 cm in a Line-Of-Sight scenario, and increasing the maximum communication distance by 43.5%, reaching 330 cm in the case of a Non-Line-Of-Sight transmission.

Light energy harvested flexible wireless sensing for disinfection sterilization in food storage

Cold chain logistics involves all aspects of food storage, transport, and sales. This study focuses on innovating cold storage disinfection within this context. Regular disinfection reduces microorganism growth, improves food quality, and ensures safety. Traditional methods lack automation, accurate monitoring, and responsive control. Conventional sensors are unsuitable for curved bottles and need frequent power changes. This paper proposes a light energy harvested flexible wireless sensing for disinfection sterilization in food storage (FLWDS). FLWDS comprises five parts: light energy harvesting and power supply node (LEPN), sensing node, control node, monitoring node, and host computer. A predictive control model improves response speed and accuracy. Bluetooth technology ensures real-time communication between nodes. FLWDS collects light energy inside the cold store as a supplementary energy source and can be used in curved structures with a response time of less than 1 s. The maximum communication distance is 40 m. The flexible level sensing system can be designed according to the induction pad’s length, with a measurement accuracy of 0.3 mm, sampling every 4.8 ms, and a resolution of 0.2 mm. FLWDS provides self-powered flexible wireless sensing, ensuring accurate liquid level measurement, improved food quality, reduced pollution, and increased sustainability.

Design of IIOT Device Based on LoRa for Parsing Data Directly to SCADA System

As the revolution industry 4.0 was started as well as the productivity increases, the need for data analysis increases. Some industries have wide production area and they need long wire to connected between office for transferring data. A wireless system is one of solution to overcome this issue so that the technique of parsing data to expand coverage area for both local and remote systems. In this research, a device that supports IIOT (Industry on Internet of Things) will be designed by utilizing LoRa technology connected to a SCADA (Supervisory Control and Data Acquisition) system for direct parsing data. By using a SCADA system concept and incorporating wireless system as well as connecting to internet so the industrial system can be monitoring from anywhere so productivity can be increased. To test the proposed design, the two scenarios of performance test have been done, they are communicating distance test and the parsing data between two nodes LoRa as well as connecting to SCADA system. The first scenario results in the maximum communication distance that can still carried out reaching 400m. Meanwhile, the experience of second scenario on the IIOT device prototype produces accurate data so that it can be implemented in the wider industry

Network Topology Reconfiguration-Based Blind Equalization over Sensor Network.

Distributed in-network processing has garnered much attention due to its capability to estimate the unknown parameter of interest from noisy measurements based on a set of cooperating sensor nodes. In previous studies, distributed in-network processing mainly focused on short-distance communication systems, wherein sensor nodes collect certain parameters of interest within their maximum communication distance. In addition, the estimation of certain parameter vectors of interest from noisy measurements, relying heavily on training signals, is achieved with a non-blind distributed estimation algorithm. However, in some applications, acquiring knowledge of training signals beforehand is difficult. Therefore, it is necessary to perform distributed estimation algorithms for receivers without training signals, a concept known as blind distributed estimation. In this paper, the generalized Sato algorithm is used to design the blind equalizer for the signal estimation. In addition, we consider extending the short-distance communication system to a long-distance communication system for an unmanned aerial vehicle (UAV) cooperating with sensor nodes in the wireless sensor network (WSN). In this scenario, the data signal is transmitted from a UAV to the WSN and is received by sensor nodes. However, the performance of the blind equalizer is susceptible to the transmission channel in long-distance communication systems. Here, we present a network topology reconfiguration approach to address the issue of distributed blind equalization. The objective of the proposed method is to discard the influence of ill-channels on the other sensor nodes by detecting ill-channels and redesigning the sensor node weights. Through computer simulation experiments, we evaluated the performance of the blind equalizer using the average mean square error (MSE) and average symbol error rate (SER). In the results of the computer simulation experiments, the blind equalizer using the proposed method outperformed the conventional methods in terms of prediction accuracy and convergence speed.

Boosting asymmetric measurement-device-independent quantum key distribution via numerical-analysis technology

Asymmetric measurement-device-independent quantum key distribution (MDI-QKD) enables building a scalable, high-rate quantum network with an untrusted relay in real-world scenarios. In this study, we improve the performance of asymmetric MDI-QKD using numerical analysis techniques. Simulation results show a twofold increase in tolerance to basis misalignment compared to the previous state-of-the-art method. Specifically, for instances of substantial basis misalignment, the key rate increases by an order of magnitude, and the maximum communication distance extends by 20 km. Our work significantly enhances the robustness and feasibility of asymmetric MDI-QKD, thereby promoting the widespread deployment of MDI-QKD networks.

Optimization Algorithm for AoI-Based UAV-Assisted Data Collection

Regarding the issue of information freshness in systems that aid in data collection using unmanned aerial vehicles (UAVs), a data collection algorithm that is based on freshness and UAV assistance is proposed. Under the limitations of wireless sensor node communication distance and UAV parameters, the optimization problem of minimizing the average spatial correlation age of information (SCAoI) of all nodes in the area is set up. This problem is solved by optimizing the number of clusters, UAV flight trajectories, and the order of data collection from cluster member nodes. The maximum communication distance of the nodes is used as the cluster formation radius, and the maximum-minimum distance clustering algorithm is used to cluster the nodes in the region to obtain the minimum number of clusters. After it has been proven that the trajectory optimization problem in this study is NP-hard, the ant colony algorithm is applied to obtain the minimum flight time and the corresponding trajectory. By using the greedy algorithm to determine the member nodes in the sequence of data collection for a cluster, the instantaneous SCAoI of the UAV arriving at the cluster head is solved. Simulation results show that the proposed algorithm in this paper can effectively improve the freshness of data and reduce the average SCAoI of the system compared with the algorithm in the comparative literature, reducing the average SCAoI by about 61%.

Low-frequency magnetoelectric capacitively-coupled receiving antenna with enhanced transmission stabilities under low input power density

Exploiting a more stabilized transmission strategy in magnetoelectric (ME) antennas for near-field communication under lower input power density is still challenging since the strain-mediated ME voltage is easily vulnerable to ambient interferences with significant anisotropy. In this work, a low-frequency (LF) receiving ME antenna system, consisting of transmitting coil and Ni0.8Zn0.2Sm0.02Fe1.98O4/PZT/Ni0.8Zn0.2Sm0.02Fe1.98O4 ME laminate, was proposed and established with the quasi-isotropic response, enhanced stabilities and limit of detection (LOD) of communication distance by capacitively-coupled mode. Experimental results showed that a more uniform receiving response in capacitance with 360° rotating of the ME antenna by a nearly circular response. Transmission stabilities were further evaluated by continuous collected data for 100 min, a near-flat capacitance response with standard Gaussian distribution (μ = 27.48nF and σ2 = 6.37 × 10−6nF) was obtained, and the estimated uncertainty shows one order of magnitude lower than that of voltage capturing mode. Under lower input power density of 15 μW/cm3, comparison studies of the LOD in transmission distance of the ME antennas were implemented, and the maximum effective communication distance of 100 cm for the ME antenna can be reached. The findings provide the possibility of using capacitively-coupled receiving mode of the ME antenna with enhanced stabilities under low input power density.

On the use of fuzzy preorders and asymmetric distances for multi-robot communication

<abstract><p>One of the main problems to be addressed in a multi-robot system is the selection of the best robot, or group of them, to carry out a specific task. Among the large number of solutions provided to allocate tasks to a group of robots, this work focuses on swarm-like approaches, and more specifically on response-threshold algorithms, where each robot selects the next task to perform by following a Markov process. To the best of our knowledge, the current response-threshold algorithms do not provide any formal method to generate new transition functions between tasks. Thus, this paper provides, for the first time, a mathematical model, as based on the so-called fuzzy preorders, for the allocation of tasks to a collective of robots with communication capabilities. In our previous work, we proved that transitions in the aforementioned process can be modeled as fuzzy preorders, constructed through the aggregation of asymmetric distances, in such a way that each robot makes its decision without taking into account the decisions of its teammates. Now, we extend this model in such a way that each robot will take into account the number of robots previously allocated for each task. To implement this method, a very simple communication mechanism has been considered. Several simulations have been carried out in order to validate our approach. The results confirm that fuzzy preorders are able to model the evolution of the system when this type of communication is considered and show when and how the communication process improves the system's performance. Experimental results show the existence of a set of good values for the maximum communication distance between robots and that these values depend on the distribution of the tasks in the environment. Thus, in some cases, a better communication mechanism does not imply better results.</p></abstract>

Sistem Komunikasi Wearable Yang Menerapkan PCB Fleksibel

The rapid adaptation of Wearable Communication technology to be applied in various fields has shown a remarkable development profile over the past decade. In this research project, a prototype wearable device operating at a frequency of 2.4 GHz was developed using rice husk fiber composite material to construct a flexible PCB Board as a circuit path and shield for IoT component modules and practically tested. This wearable device is designed to transfer video and image streaming data in indoor and outdoor scopes. The sensing object or location captured using the wearable device placed on the user's shirt is connected to an access point and will send the data to a registered server or authorized receiving station. The first trials of the fabricated wearable devices have shown excellent data transmission conducted in two different environments. The maximum communication range between the wearable device and the access point was 87 meters in the indoor test while in the outdoor test the maximum communication distance was 60 meters. During the communication range, the transmission quality degraded so that the sending signal strength during the indoor test was 398 kb/s and the outdoor test was 299 kb/s.

Performance analysis of a Vehicular Ad Hoc network Using LoRa technology and IoT devices in Amazon Rivers

Several remote communities in the Amazon region are isolated from means of access to data communication. Thus, this work proposes a communication alternative with low cost and low energy consumption based on LoRa devices. The proposal is to create an Ad Hoc Network using a transmitter device fixed on a boat and a receiver device fixed on a riverside house on the banks of the Solimões River - Amazonas. The metrics evaluated in this experiment were: Maximum Range, Maximum Time, Communication Distance, Communication Time, and Packet Delivery Rate. The results showed a 78% package delivery rate at the Maximum Range of 1563 m as the boat moved away from or approached the riverside man’s house. We conclude that the results were satisfactory within the parameters that the devices were configured and the conditions of the study scenario.

Real-Time Underwater Wireless Optical Communication System Based on LEDs and Estimation of Maximum Communication Distance.

This paper presents a real-time underwater wireless optical communication (UWOC) system. The transmitter of our UWOC system is equipped with four blue LEDs, and we have implemented pre-emphasis technology to extend the modulation bandwidth of these LEDs. At the receiver end, a 3 mm diameter APD is utilized. Both the transmitter and receiver are housed in watertight chassis and are submerged in a water pool to conduct real-time underwater experiments. Through these experiments, we have obtained impressive results. The data rate achieved by our system reaches up to 135 Mbps, with a BER of 5.9 × 10-3, at a distance of 10 m. Additionally, we have developed a convenient method for measuring the underwater attenuation coefficient, using which we have found the attenuation coefficient of the water in experiments to be 0.289 dB/m. Furthermore, we propose a technique to estimate the maximum communication distance of an on-off keying UWOC system with intersymbol interference, based on the Q factor. By applying this method, we conclude that under the same water quality conditions, our system can achieve a maximum communication distance of 25.4 m at 80 Mbps. Overall, our research showcases the successful implementation of a real-time UWOC system, along with novel methods for measuring the underwater attenuation coefficient and estimating the maximum communication distance.

A Water-Resistant, Self-Healing Encapsulation Layer for a Stable, Implantable Wireless Antenna.

Polymers for implantable devices are desirable for biomedical engineering applications. This study introduces a water-resistant, self-healing fluoroelastomer (SHFE) as an encapsulation material for antennas. The SHFE exhibits a tissue-like modulus (approximately 0.4 MPa), stretchability (at least 450%, even after self-healing in an underwater environment), self-healability, and water resistance (WVTR result: 17.8610 g m-2 day-1). Further, the SHFE is self-healing in underwater environments via dipole-dipole interactions, such that devices can be protected from the penetration of biofluids and withstand external damage. With the combination of the SHFE and antennas designed to operate inside the body, we fabricated implantable, wireless antennas that can transmit information from inside the body to a reader coil that is outside. For antennas designed considering the dielectric constant, the uniformity of the encapsulation layer is crucial. A uniform and homogeneous interface is formed by simply overlapping two films. This study demonstrated the possibility of wireless communication in vivo through experiments on rodents for 4 weeks, maintaining the maximum communication distance (15 mm) without chemical or physical deformation in the SHFE layer. This study illustrates the applicability of fluoroelastomers in vivo and is expected to contribute to realizing the stable operation of high-performance implantable devices.

Joint Path and Multi-Hop Communication Node Location Planning in Cluttered Environment

In the communication-constrained operating environment, a unmanned aerial vehicle (UAV) needs to plan a feasible path from the starting point to the endpoint while planning the node deployment location for multi-hop communication to establish an information pathway. In this study, a new algorithm was designed for joint path and multi-hop communication node location planning in cluttered environments based on rapidly-exploring random trees star (RRT*) algorithm. The maximum communication distance constraint between nodes was obtained based on the signal-free propagation model, whereas the communication node loss and path loss were established as joint optimization objectives. In bidirectional random tree growth, the structure of the trees was optimized according to the value of the loss function, and optimal path and node location planning were finally achieved through continuous growth and iteration. When tested in different complexity-barrier environments and compared to RRT*, Informed-RRT*, and IB-RRT* algorithms, the paths in the planning results of the new algorithm are close to those of the comparison algorithms; however, the number of nodes decreases significantly, which proves the effectiveness of the newly proposed algorithm.

Developing hybrid car-to-car communication system based on MIMO visible light and radio frequency

This paper combines the advantages of both VLC communication and RF communication for car-to-car applications to achieve a higher data rate, more range coverage, smaller delay, and smaller BER. In the proposed scheme, the VLC maximum communication distance is chosen as 100 m per-hop approximately, which can be extended through multi-hop up to the timeout window of 5 hops. In contrast, the RF maximum communication distance is chosen as 200 m per-hop approximately, which is reasonable at the frequency band of 70 GHz to 90 GHz due to the high attenuation at this frequency band. A MATLAB simulation for a car-to-car framework is built to demonstrate and compare the BER, throughput, and delay outcomes at a hybrid VLC and RF communication. Our results show that VLC can achieve up to four times of the RF throughput while maintaining low BER of 10−6 and small delay of 10−4 with respect to RF communication only.

New approach for designing an underwater free-space optical communication system

Ocean observation system that involves multiple underwater vehicles and seafloor nodes plays an important role in better learning the ocean, where underwater wireless communication is mandatory for massive data interaction. Optical communication that has wide bandwidth and comprehensive working distance is the preferred method compared to acoustic and other methods. However, the presence of directionality makes the optical method difficult to use especially when the transceiver is equipped on a motive vehicle. In this study, an underwater free-space optical communication method of transmitting information is proposed. Characteristics of underwater optical transmission, as well as the photoelectric signal processing and modulation and demodulation algorithms, are studied and modeled. New approach for realizing underwater free-space optical communication is proposed and simulated. A prototype including a free-space optical transmitter and a receiver is developed; tests in different scenarios were carried out, and the results were observed: (1) by using the minimum number of LEDs, the effect of uniform lighting in space is achieved, and the transmitter coverage reaches 160°. (2) When the power of the transmitter is 10 W and the communication rate is 1 Mbps, the maximum communication distance reaches 13 m.

Photon subtraction-based continuous-variable measurement-device-independent quantum key distribution with discrete modulation over a fiber-to-water channel

We propose a discrete-modulated continuous-variable measurement-device-independent quantum key distribution protocol over a fiber-to-water channel. Different from optical fibers, the underwater channel has more severe optical attenuation because of optical absorption and scattering, which reduces the maximum communication distance. To enhance the performance of the protocol, the photon subtraction operation is implemented at the modulator side. We carry out a performance simulation in two different kinds of seawater channel, and the result shows that the scheme with photon subtraction has a longer secure communication distance under certain conditions.

Communication Distance Estimation for Power Line Communication Using Various Differently Constituted Power Cables

The use of PLC (power line communication) is growing as the adoption of IoT technology becomes more widespread. However, the maximum communication distance between PLC modems cannot yet be clearly defined since the communication characteristics of the power lines used for PLC are not formally specified. In this paper, the propagation characteristics in the high‐speed PLC communication band of 2–30 MHz were investigated when equipment is not connected to the power line except both ends. The line constants for five typical types of cables used as single‐phase and two‐wire power lines were measured. Our results showed that different cables have markedly different transmission characteristics. The attenuation constant varied up to fourfold depending on the cable insulator material. We also derived a method of estimating the communication distance for different cables for application of the HD‐PLC system, which is the most commonly used type of high‐speed PLC. The measurement result by using VCT cable was almost agreed with the estimated value. By comparing the estimated distance with the experimental results, we show that the transmission distance can be estimated with sufficient accuracy for practical use. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Two-Feedback Loop Shunt Regulator Based on PWM RF Power Detector Aiming RFID Applications

The paper presents a novel shunt voltage regulation architecture that uses an RF power detector, based on Pulse Width Modulation (PWM) technique, aiming at magnetic coupled Radio-Frequency Identification (RFID) transponders. The proposed regulator architecture implements two feedback loops: a voltage clamping circuit that composes a fast correction loop and a slow but accurate power detector loop. The first clamping loop guarantees fast over-voltage protection, mainly in high RF power condition (short reading distance), but degrades power efficiency when in low power condition (large reading distance). The second loop corrects the imprecision of the first loop according to the detected RF input power. Therefore, it increases power efficiency and reading distance when in low RF power condition. The RF power detector architecture, based on a PWM technique, and the shunt regulator design are presented and discussed in detail. RFID power regulation issues are also discussed, followed by a brief review of RF power detector circuits. The complete regulator architecture was implemented in a 180nm CMOS low cost process and prototyped as part of a commercial low-frequency (134 kHz) RFID transponder. The complete transponder area is 870 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 870 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}^{2}$ </tex-math></inline-formula> , being 130 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 230 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}^{2}$ </tex-math></inline-formula> related to the regulator circuit only. Both resonant and supply capacitors are implemented on chip. The analog and digital functional blocks of the RFID system consume 4.5 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula> . Performance of the transponder is measured with the shunt regulator enabled and compared with the power limiting approach using only clamping diodes. Measured results show an improvement of 16.7% in the maximum communication distance between the transponder and the reader because of the proposed regulation strategy.

Security and communication distance improvement in decoy states based quantum key distribution using pseudo-random bases choice for photon polarization measurement

This paper proposes a new quantum key distribution(QKD) protocol, namely the pseudo-random bases entangled photon based QKD (PRB-EPQKD) protocol. The latest mainly focuses on three properties, including the security of the protocol, the secure key size and the maximum communication distance between legitimate communication users (Alice and Bob). To achieve this, we first consider a spontaneous-parametric-down (SPDC) photon source located in a low-earth-orbit (LEO) type satellite capable of producing and distributing entangled photons pairs to Alice and Bob. Secondly, we assume that Alice’s and Bob’s photons state measurement bases are identically generated via a pseudo-random number generator (PRNG), namely the quantum logistic map (QLM). Finally, we also assume that in addition to their photons states, Alice and Bob intentionally share a set of decoy states at each pulse with randomly selected intensity, and with the goal to detect the presence of the eavesdropper (Eve). Under these considerations, the secure key rate upper bound is evaluated applying the Gottesman-Lo-Lutkenhaus-Preskill’s (GLLP) formula, for two different implementations, namely the non-decoy states and the infinite active decoy states based QKD. It is observed a significant improvement in the secure key size and the communication distance as well, compared to existing protocols, since we realize that under daylight, downlinks satellite conditions, a kindly selected light source, and good crystal’s properties, the maximum communication distance can reach up to 70000 km. In addition, using the combined type-I and type-II SPDC photons source as our entangled photons pairs generator, significantly improved the photon mean number and render our protocol more robust against photon number division attack and against attenuation-induced atmospheric propagation. Furthermore, the protocol is more secure as compared to existing ones, given that any eavesdropper must crack simultaneously the chaotic system used as PRNG and the QKD system, before getting any useful information as regards to the measurement bases used by Alice and Bob, and thus the secure key.