Wireless Radio Link Research Articles

Residual multiscale attention based modulated convolutional neural network for radio link failure prediction in 5G

In the realm of the 5 G environment, Radio Access Networks (RANs) are integral components, comprising radio base stations communicating through wireless radio links. However, this communication is susceptible to environmental variations, particularly weather conditions, leading to potential radio link failures that disrupt services. Addressing this, proactive failure prediction and resource allocation adjustments become crucial. Existing approaches neglect the relationship between weather changes and radio communication, lacking a holistic view despite their effectiveness in predicting radio link failures for one day. Therefore, the Dynamic Arithmetic Residual Multiscale attention-based Modulated Convolutional Neural Network (DARMMCNN) is proposed. This innovative model considers radio link data and weather changes as key metrics for predicting link failures. Notably, the proposed approach extends the prediction span to 5 days, surpassing the limitations of existing one-day prediction methods. In this, input data is collected from the Radio Link Failure (RLF) prediction dataset. Then, the distance correlation and noise elimination are used to improve the quality and relevance of the data. Following that, the sooty tern optimization algorithm is used for feature selection, which contributes to link failures. Next, a multiscale residual attention modulated convolutional neural network is applied for RLF prediction, and a dynamic arithmetic optimization algorithm is accomplished to tune the weight parameter of the network. The proposed work obtains 79.03 %, 65.93 %, and 67.51 % of precision, recall, and F1-score, which are better than existing techniques. The analysis shows that the proposed scheme is appropriate for RLF prediction.

Demonstration of M-QAM OFDM bidirectional 60/25 GHz transmission over 10 km Fiber, 100 m FSO and 2 m radio seamless heterogeneous fronthaul link

In this paper, we demonstrate the experimental transmission of 16- and 64- quadrature amplitude modulation (QAM) Long Term Evolution - Orthogonal Frequency Division Multiplexing (LTE-OFDM) signals by using millimetre wave frequencies at 60 GHz and 25 GHz for downlink and uplink, respectively, over a heterogeneous optical fronthaul infrastructure. A directly modulated laser was employed for both links, which enables the cost-effective full-duplex system proposal. The bidirectional link consists of a 10 km of single mode fiber, a 100 m long free space optics channel and 2 m long wireless radio link, which brings flexibility for future wireless networks. The error vector magnitude (EVM) parameter is measured for a range of the received optical and electrical power as well as the signal-to-noise ratio. A comprehensive estimation of penalty factors in the different network segments is presented. The successful transmission over the whole proposed network with the EVM below the required limit of 9 % for 64-QAM with 20 MHz bandwidth is experimentally demonstrated for the received optical power of −2.7 dBm and −1 dBm for the downlink and uplink, respectively.

A D-Band 16-Element Phased-Array Transceiver in 55-nm BiCMOS

A 16-element 140–160-GHz phased array transceiver is reported. The chipset is fabricated using STMicroelectronics’ 55-nm SiGe BiCMOS process. Five different chips are implemented: a 4-channel transmitter with a maximum gain per channel of 15 dB and 0-dBm saturated output power; a 4-channel receiver with a maximum gain of 8 dB, a −10.4-dBm input 1-dB compression point (IP1 dB), and a minimum noise figure (NF) of 15.6 dB per channel; a 0–1-GHz to 140–160-GHz I/Q up-converter with integrated frequency doubler, exhibiting a −13.5-dB conversion gain (CG) and −6-dBm output 1-dB compression point using a 70–80-GHz local oscillator (LO); a 140–160-GHz to 0–1-GHz I/Q down-converter with integrated frequency doubler, exhibiting a CG of 0 dB and IP1 dB of 0 dBm using a 70–80-GHz LO and an 11.67–13.33-GHz to 70–80-GHz x6 frequency multiplier for the LO, delivering 5.6-dBm maximum output power. The chips are assembled together with 16 cavity-backed aperture-coupled patch antennas using a high-performance and low-cost commercial PCB, supported over a heat sink. The main challenges encountered during the integration of the proposed system are also discussed. The complete system is used to build a wireless radio link in the laboratory, demonstrating 2-D beam steering in a range of ±30°.

Smart detection and prevention procedure for DoS attack in MANET

A self-organized wireless communication short-lived network containing collection of mobile nodes is mobile ad hoc network (MANET). The mobile nodes communicate with each other by wireless radio links without the use of any pre-established fixed communication network infrastructure or centralized administration, such as base stations or access points, and with no human intervention. In addition, this network has potential applications in conference, disaster relief, and battlefield scenario, and have received important attention in current years. There is some security concern that increases fear of attacks on the mobile ad-hoc network. The mobility of the NODE in a MANET poses many security problems and vulnerable to different types of security attacks than conventional wired and wireless networks. The causes of these issues are due to their open medium, dynamic network topology, absence of central administration, distributed cooperation, constrained capability, and lack of clear line of defense. Without proper security, mobile hosts are easily captured, compromised, and attacked by malicious nodes. Malicious nodes behavior may deliberately disrupt the network so that the whole network will be suffering from packet losses. One of the major concerns in mobile ad-hoc networks is a traffic DoS attack in which the traffic is choked by the malicious node which denied network services for the user. Mobile ad-hoc networks must have a safe path for transmission and correspondence which is a serious testing and indispensable issue. So as to provide secure communication and transmission, the scientist worked explicitly on the security issues in versatile impromptu organizations and many secure directing conventions and security measures within the networks were proposed. The goal of the work is to study DoS attacks and how it can be detected in the network. Existing methodologies for finding a malicious node that causes traffic jamming is based on node’s retains value. The proposed approach finds a malicious node using reliability value determined by the broadcast reliability packet (RL Packet). In this approach at the initial level, every node has zero reliability value, specific time slice, and transmission starts with a packet termed as reliability packet, node who responded properly in specific time, increases its reliability value and those nodes who do not respond in a specific time decreases their reliability value and if it goes to less than zero then announced that it’s a malicious node. Reliability approach makes service availability and retransmission time.

Statistical analysis of MIMO mobile-to-mobile communication channel employing elliptical scattering geometry

ABSTRACT Geometrical-based stochastic channel modelling approach of the wireless propagation radio links remained the topic of interest in the researcher community over the last few decades. Researchers and theorists have examined and verified through measurements the impact of various parameters of the channel on the correlations between the array elements of multiple-input and multiple-output (MIMO) antenna for different wireless propagation scenarios. In the previously proposed elliptical-based scattering channel model , mobile stations (MSs) are assumed to be fixed at the centre of elliptical geometry that resembles the situation when fast-moving calling subscribers to reside in streets, canyons or on the highways, where the scattering objects like vegetation, high-rise structures and safety walls are present at roadside terrain. In this paper, the elliptical-scattering channel model is analysed for power density spectrum (PDS) when any of the MSs moves with some velocity in any direction. Moreover, the derived theoretical results are plotted for various channel parameters like relative velocities of the MSs, and normalized frequency used. Finally, the result of the PDS of the proposed M2M elliptical scattering model is compared with the results of the F2M channel model.

Deep learning approach for device‐free localisation based on internet of things

The device-free localisation, which neither requires the targets to carry any electronic device nor participate in the position process proactively, is an innovated and prospective technique. Traditional device-free techniques include computer vision, infrared sensor, indoor radar etc. Since there is a rapid development of the internet of things (IoT) brings massive wireless radio links, it is possible to achieve the device-free localisation by investigating the link quality indicator of wireless links. In this Letter, the authors propose a device-free localisation procedure to position the target by acquiring all the wireless link indictors in the IoT network, utilising deep learning to train the deep neural network. The experiment shows the average positioning error can be <0.2 m in an experimental environment of 160 square metres.

A NOVEL HYBRID OPPORTUNISTIC SCALABLE ENERGY EFFICIENT ROUTING DESIGN FOR LOW POWER, LOSSY WIRELESS SENSOR NETWORKS

Opportunistic Routing (OR) scheme increases the transmission reliability despite the lossy wireless radio links by exploiting the broadcast nature of the wireless medium. However, OR schemes in low power Wireless Sensor Network (WSN) leads to energy drain in constrained sensor nodes due to constant overhearing, periodic beaconing for Neighbourhood Management (NM) and increase in packet header length to append priority wise sorted Forwarding Candidates Set (FCS) prior to data transmission. The focus of this work is to propose a hybrid opportunistic energy efficient routing design for large scale, low power and lossy WSN. This design avoids periodic 'hello' beacons for NM, limits constant overhearing and increase in packet header length. There are two modes of operation i) opportunistic ii) unicast mode. The sender node adopts opportunistic forwarding for its initial data packet transmission and instead of pre-computing the FCS, it is dynamically computed in a completely distributed manner. The nodes part of FCS based on cross layered multi-metrics and fuzzy decision logic determines its priority level to compute Dynamic Holding Delay (DHD) for effective timer coordination. The differentiated back off implementation along with DHD enables the higher priority candidate that had received data packet to forward the packet first and facilitates others to cancel its timer upon overhearing. The sender node switches to unicast mode for successive transmissions to achieve energy efficiency till link-level transmission error occur. Opportunistic mode is used as the first and last resort to increase the transmission reliability. Simulation results in NS2 show significant increase in Packet Delivery Ratio (PDR), decrease in both average energy consumption per node and Normalized Energy Consumption (NEC) per packet in comparison with existing protocols.

A Novel Hybrid Opportunistic Scalable Energy Efficient Routing Design for Low Power, Lossy Wireless Sensor Networks

Opportunistic Routing (OR) scheme increases the transmission reliability despite the lossy wireless radio links by exploiting the broadcast nature of the wireless medium. However, OR schemes in low power Wireless Sensor Network (WSN) leads to energy drain in constrained sensor nodes due to constant overhearing, periodic beaconing for Neighbourhood Management (NM) and increase in packet header length to append priority wise sorted Forwarding Candidates Set (FCS) prior to data transmission. The focus of this work is to propose a hybrid opportunistic energy efficient routing design for large scale, low power and lossy WSN. This design avoids periodic 'hello' beacons for NM, limits constant overhearing and increase in packet header length. There are two modes of operation i) opportunistic ii) unicast mode. The sender node adopts opportunistic forwarding for its initial data packet transmission and instead of pre-computing the FCS, it is dynamically computed in a completely distributed manner. The nodes part of FCS based on cross layered multi-metrics and fuzzy decision logic determines its priority level to compute Dynamic Holding Delay (DHD) for effective timer coordination. The differentiated back off implementation along with DHD enables the higher priority candidate that had received data packet to forward the packet first and facilitates others to cancel its timer upon overhearing. The sender node switches to unicast mode for successive transmissions to achieve energy efficiency till link-level transmission error occur. Opportunistic mode is used as the first and last resort to increase the transmission reliability. Simulation results in NS2 show significant increase in Packet Delivery Ratio (PDR), decrease in both average energy consumption per node and Normalized Energy Consumption (NEC) per packet in comparison with existing protocols.

Development of a Novel Protocol for Improvement of Qos Inwireless Sensor Networks: P-Rpeh

The Wireless Sensor Networks (WSN) plays an important function in wireless communication because of its top notch utility and benefits. Wireless Sensor Networks have thousands or hundreds of potential nodes, which are minute computer like, and areable of measuring the physical characteristics of the neighboring environment location and thentransmit the gathered information using wireless radio links. This paper proposes an efficient scheme for resource allocation used for the transmission of data using priority in the nodes. The protocol, Medium Access Control (MAC) has been devisedfor evaluating the performance. The parameters considered are bandwidth, energy consumption, delay, throughput andpacket delivery ratio. A new MAC protocol,”P-RPEH”(Priority that is based on the Residual Power and Energy Harvesting rate), using priority in nodes with maximumenergyis proposed. The proposed method is compared with the PRIN (Priority in Node) and PRIMA (Priority based MAC)existing protocols. The results obtained from the new protocol proves that, the newproposed protocoloutperforms the existingmethods in terms of bandwidth, delay, energy, throughput and the ratio of packets delivered.

An investigation on power loss of an out-to-in body wireless radio frequency link.

Implantable medical sensors for monitoring and transmitting physiological signals like blood glucose, blood oxygen, electrocardiogram, and endoscopic video present a new way for health care and disease prevention. Nevertheless, the signals transmitted by implantable sensors undergo significant attenuation as they propagate through various biological tissue layers. This paper mainly aims to investigate the power loss of an out-to-in body wireless radio frequency link at 2.45GHz. Two simulation models including the single-layer human tissue model and three-layer human tissue model were established, applying the finite element method (FEM). Two experiments using physiological saline and excised porcine tissue were conducted to measure the power loss of a wireless radio frequency link at 2.45GHz. Various communication distances and implantation depths were investigated in our study. The results from our measurements show that each 2cm increase in implantation depth will result in an additional power loss of about 10dB. The largest difference in values obtained from the measurements and the simulations is within 4dB, which indicates that the experiments are in good agreement with the simulations. These results are significant for the estimate of how electromagnetic energy changes after propagating through human tissues, which can be used as a reference for the link budget of transceivers or other implantable medical devices.

A Novel Hybrid Opportunistic Scalable Energy Efficient Routing Design for Low Power, Lossy Wireless Sensor Networks

Opportunistic Routing (OR) scheme increases the transmission reliability despite the lossy wireless radio links by exploiting the broadcast nature of the wireless medium. However, OR schemes in low power Wireless Sensor Network (WSN) leads to energy drain in constrained sensor nodes due to constant overhearing, periodic beaconing for Neighbourhood Management (NM) and increase in packet header length to append priority wise sorted Forwarding Candidates Set (FCS) prior to data transmission. The timer-based coordination mechanism incurs the least overhead to coordinate among the FCS that has successfully received the data packet for relaying the data in a multi-hop manner. This timer-based mechanism suffers from duplicate transmissions if the FCS is either not carefully selected or coordinated. The focus of this work is to propose a hybrid opportunistic energy efficient routing design for large scale, low power and lossy WSN. This design avoids periodic 'hello' beacons for NM, limits constant overhearing and increase in packet header length. There are two modes of operation i) opportunistic ii) unicast mode. The sender node adopts opportunistic forwarding for its initial data packet transmission and instead of pre-computing the FCS, it is dynamically computed in a completely distributed manner. The eligible nodes to be part of FCS will be neighbour nodes at lower corona level than the sender with respect to the sink and remaining energy above the minimum threshold. The nodes part of FCS based on crosslayered multi-metrics and fuzzy decision logic determines its priority level to compute Dynamic Holding Delay (DHD) for effective timer coordination. The differentiated back off implementation along with DHD enables the higher priority candidate that had received data packet to forward the packet first and facilitates others to cancel its timer upon overhearing. The sender node switches to unicast mode of forwarding for successive transmissions by choosing the forwarding node with maximum trust value as it denotes the stability of the temporally varying link with respect to the forwarder. The sender node will revert to opportunistic mode to increase transmission reliability in case of link-level transmission error or no trustworthy forwarders. Simulation results in NS2 show significant increase in Packet Delivery Ratio (PDR),decrease in both average energy consumption per node and Normalized Energy Consumption (NEC) per packet in comparison with existing protocols.

28 GHz Wireless Backhaul Transceiver Characterization and Radio Link Budget

Millimeter wave communication is one of the main disruptive technologies in upcoming 5G mobile networks. One of the first candidate applications, which will be commercially ready by 2020, is wireless backhaul links or wireless last mile communication. This paper provides an analysis of this use-case from radio engineering and implementation perspectives. Furthermore, preliminary experimental results are shown for a proof-of-concept wireless backhaul solution developed within the EU-KR 5GCHAMPION project, which will be showcased during the 2018 Winter Olympic Games in Korea. In this paper, we verify system level calculations and a theoretical link budget analysis with conductive and radiated over-the-air measurements. The results indicate that the implemented radio solution is able to achieve the target key performance indicator, namely, a 2.5 Gbps data rate on average, over a range of up to 200 m.

Energy aware hybrid multicast routing in mobile ad hoc networks: Zone based approach

Mobile ad hoc networks (MANETs) are formed dynamically by an autonomous system of mobile nodes that are connected via wireless radio links. Hybrid routing strategy is widely used in hierarchical routing protocols to reduce the control overheads and packet delivery delay in MANETs. In this paper, we propose zone-based energy aware hybrid multicast routing scheme (ZEHMRP) for MANET. Our scheme operates in the following phases: 1) computation of node remaining energy (RE) by designing energy model; 2) prune the nodes having remaining energy less than predefined threshold value; 3) discovery of multiple routes using request and reply packets; 4) selection of stable route among multiple routes by considering node remaining energy and density; 5) route maintenance for route breaks and node failures; 6) simulation evaluation for various parameters. It is observed that ZEHMRP outperforms the zone routing protocol (ZRP) for various parameters like packet delivery ratio, end-to-end delay, jitter, and control overheads.

Inter-Cluster Design of Wireless Fronthaul and Access Links for the Downlink of C-RAN

This letter studies the joint design of wireless fronthaul and radio access links for the downlink of a cloud radio access network (C-RAN). In a C-RAN, high spectral efficiency can be achieved by migrating the baseband processing functionalities to a baseband processing unit (BBU). However, due to the increased system cost, the size of cluster should be kept relatively small, and hence the spectral efficiency performance tends to be limited by the impact of inter-cluster interference signals. This letter tackles the problem of jointly optimizing the fronthaul and access links across multiple clusters with the goal of maximizing the sum-rate of all the user equipments belonging to the clusters while satisfying the power constraints at the BBUs and remote radio heads. Via numerical results, the effectiveness of the proposed algorithm is confirmed.

Characterization of In-Body to On-Body Wireless Radio Frequency Link for Upper Limb Prostheses.

Wireless implanted devices can be used to interface patients with disabilities with the aim of restoring impaired motor functions. Implanted devices that record and transmit electromyographic (EMG) signals have been applied for the control of active prostheses. This simulation study investigates the propagation losses and the absorption rate of a wireless radio frequency link for in-to-on body communication in the medical implant communication service (MICS) frequency band to control myoelectric upper limb prostheses. The implanted antenna is selected and a suitable external antenna is designed. The characterization of both antennas is done by numerical simulations. A heterogeneous 3D body model and a 3D electromagnetic solver have been used to model the path loss and to characterize the specific absorption rate (SAR). The path loss parameters were extracted and the SAR was characterized, verifying the compliance with the guideline limits. The path loss model has been also used for a preliminary link budget analysis to determine the feasibility of such system compliant with the IEEE 802.15.6 standard. The resulting link margin of 11 dB confirms the feasibility of the system proposed.

Rainfall Zoning and Rain Attenuation Mapping for Microwave and Millimetric Applications in Central Africa

Rainfall attenuation is among the major factors often considered, in the design of wireless networks, operating at higher bands within microwave and millimeter wave spectrum. At tropical and equatorial locations, not only is the occurrence of rainfall events of serious concern to terrestrial and satellite communication systems, but also the high intensity of rain rates attained during such events. In this paper, daily rainfall measurements from the Rwanda Meteorology Agency (Meteo Rwanda) are obtained for 30 locations within equatorial Rwanda (between latitudes of 1°2'S and 2°45'S and longitudes of 28° 45'E and 30052'E), Central Africa, to develop rain rate and rain attenuation maps for wireless radio links. From these long term annual rainfall measurements spanning a minimum of 10 years at these locations, rainfall rate statistics estimated from appropriate models are applied to determine radio link availabilities between 99% and 99.999%. Furthermore, specific attenuation estimates due to rainfall are proposed from International Telecommunication Union (ITU) recommendations at selected frequencies of the microwave and millimeter bands, for the design of wireless networks. Results obtained from this approach incorporating both rainfall rate zones and specific attenuation over Rwanda, are presented as spatial contour maps representations for different ranges of link availability. It is envisaged that these maps will serve as a useful resource for quick reference for future link design estimates, for terrestrial and satellite networks across Rwanda and Central Africa.

Characterization of path loss and absorption for a wireless radio frequency link between an in-body endoscopy capsule and a receiver outside the body

Abstract Physical-layer characterization is important for design of in-to-out body communication for wireless body area networks (WBANs). This paper numerically investigates the path loss and absorption of an in-to-out body radio frequency (RF) wireless link between an endoscopy capsule and a receiver outside the body using a 3D electromagnetic solver. A spiral antenna in the endoscopy capsule is tuned to operate in the Medical Implant Communication Service (MICS) band at 402 MHz, accounting for the properties of the human body. The influence of misalignment, rotation of the capsule, and three different human models are investigated. Semi-empirical path loss models for various homogeneous tissues and 3D realistic human body models are provided for manufacturers to evaluate the performance of in-body to out-body WBAN systems. The specific absorption rate (SAR) in homogeneous and heterogeneous body models is characterized and compliance is investigated.

Long Distance Data Wireless Link Lab

This paper shows a lab homework assignment about long distance wireless LAN data links taught as part of a course at the Computer Engineering career at the Universidad Nacional de Tucumán. Throughout the paper, analytical estimations are discussed first and, based on them, feasibility analysis of the link is carried on. Then, real tests are made on short and long distance radio links and compared, arriving to important conclusions about the homework and the behavior of wireless radio link.

Inspiring Student Learning in ICT Communications Electronics through a New Integrated Project-Based Learning Approach

The design and implementation of a new project-based learning approach for student learning in laboratory communications electronics is presented. A new aspect of this approach is to inspire student learning by engaging them in real applications they can relate to, which is based on providing a platform for students to learn the subject at the level of communication systems and to structure it around electronic subsystems that integrate to form the complete system. The design of how to divide the large overall project into component integrative tasks that the students can manage is presented. The resulting integration of the individual learning tasks into the project provided students with an understanding that addresses a holistic view. The big picture approach, followed by students' study and investigation of individual elements in the subsystem and their integration to realise a real wireless radio communication link, demonstrated the benefits of project-based learning and enhanced engagement stimulating curiosity and discovery. The results of the student feedback survey indicated that students were highly motivated, and that the approach strongly supported their effective learning.

Integrating disruption-prone links into reliable networks: a transmission control protocol friendly approach

Although progress has been made to satisfy mobility at the network's edge, much work remains for deeper mobility requirements. In many emergency or military applications, fixed network infrastructure may not be available or even possible. As mobile military data requirements grow, and spectrum limitations increase, systems must better utilise the diminishing available bandwidth of wireless radio frequency and free space optical links. To achieve better utilisation, disruption-prone networks require disruption-tolerant protocols or localised buffering to mask disruptions. Transmission control protocol (TCP)/IP assumes reliable links and performs well in networks with congestion dominated packet losses, but poorly with link failure dominated packet losses. Although TCP might be altered for disruptive environments, evolutionary reasons make it difficult to do so well without partitioning networks into reliable and disruption-tolerant systems. Instead, the authors examine transport layer aware helper protocols, with intermediate buffering in routers, to assist TCP across disruption-prone network portions. The buffering does not require TCP modifications at communicating nodes and integrate well with existing routers (i.e. TCP friendly). Experimental results show that TCP can reliably establish and maintain connections under poor link availability using the buffering protocol. Few TCP connections complete without it.