Network Communication Research Articles

Exploration on Task-driven Teaching Design of Industrial Robot Operation and Programming Course in Secondary Vocational Schools

Currently, the national goal for the training of talents in vocational colleges and universities is to cultivate high-quality skilled talents with powerful practical ability, good thinking, and in line with the needs of the manufacturing industry. For the industrial robot operation and programming, which is a comprehensive practical training course with both theory and practice, focusing on the improvement of students' Introductory operation, offline programming ability, and familiarity with the use of network communication systems and other learning objectives, it is proposed to apply the "task-driven teaching method" throughout the whole teaching process to fully mobilize students' initiative and guide them to analyze the problems and improve their practical skills from different perspectives. The article focuses on the requirements of the course and discusses how to improve the student's capacity to apply theory in practice. The article focuses on the specific teaching design ideas of the task-driven teaching method and the multi-dimensional evaluation and assessment mode in this course in combination with the requirements of the course.

Enhancing connectivity/mobility in WBAN applications through detachable wearable multi-band MIMO antenna

The connectivity and mobility of a miniaturized multi-band four-port textile leaky wave multiple-input multiple-output (MIMO) antenna designed on a layer of denim (εr = 1.6, tanδ = 0.006) is enhanced by integrating it with two detachable spiral buttons designed on circular PTFE substrate (εr = 2.1, tanδ = 0.001). The connectivity and mobility enhancement of the proposed antenna is evaluated in terms of radiation and diversity parameters. Nested hexagonal split rings behind the buttons, U-shaped slots on textiles, a comb-shaped neutralization network, and an aperture-coupled feed technique are utilized. The unique structure of the buttons on a rigid substrate and the leaky wave antenna on the textile and their integration, the periodic nested elliptical and circular split ring resonators (CSRRs) slots on the aperture coupled to ground, are to expand the connectivity and mobility of the proposed MIMO antenna by offering multiple bands, higher isolation, broadside radiation, and low specific absorption rate (SAR). The leaky wave and button antennas have dimensions of 40 × 30 × 1 mm3 and a diameter of only 13 mm, respectively. The operational bands are 0.86–2.75 GHz, 2.9–4.85 GHz, 5.75–6.15 GHz, and 8–9.85 GHz, covering the L, C, S, and X bands. Additionally, diversity performance is evaluated by defining the envelope correlation coefficient (ECC), diversity gain (DG), Channel Capacity Loss (CCL), and mean effective gain (MEG). The simulation and measurement findings are in good agreement. Following that, it offers a maximum gain of 8.25 dBi, low SAR (<0.05), an ECC below 0.05, DG above 9.85 dB, CCL< 0.25 bits/s/Hz, MEG <−3 dB, Circular polarization (CP), and strong isolation (>22 dB) between every two ports. These features make the proposed antenna an ideal option for MIMO communications and suitable for wireless local area network (WLAN) and fifth-generation (5G) communications.

VSG-LFC on multi-area power system under unsecured communication channel using hybrid trigger mechanism

This paper studies the frequency fluctuation problems of a multi-area power system with renewable energy sources (RESs) under denial-of-service (DoS) attacks. (i) Due to the decoupling of the RESs from power system using electronic devices, the RESs have no natural frequency response capability, which result in decreasing of entire power system equivalent inertia with large penetration of RESs. (ii) DoS attacks cause the insecurity of network communication, which can vanish data transmission and yield data packet dropout. To address the above issues, a virtual synchronous generator (VSG) incorporated with load frequency control (LFC) method (VSG-LFC) is proposed by introducing a hybrid-triggered mechanism (HTM) to (i) reduce the system sensitivity to the penetration level of RESs; (ii) compromise between frequency regulation performance and the reasonable usage of network resource under unsecured communication environments. Then, a switched system model is constructed considering non-identical DoS attack situations. Furthermore, theoretical analyses using Lyapunov functional related methods are carry out for asymptotical mean-square stability with H∞ performance on frequency regulation. Simulation evaluations of power system verify the effectiveness of this development. It shows that in a two-area power system frequency derivation performance indicators (IAE, ITAT, ISE) in Area1 are reduced by (82.996%, 86.273%, 85.823%) and in Area2 are reduces by (77.996%, 83.613%, 82.315%).

Моделирование перехода частных пертинентностей в коллективную релевантность в интернет-коммуникации

The following study describes the core modeling principles of correspondence of private pertinence to collective relevance, analyzes the mechanisms for creating generalized content, and the formation of common significance areas in the value space of network communication. The methodological principle of the individual and collective transgression is the concept of contextual models with focal detalization. The formation of the pertinence field is described as internal relevance characterizing polylogue delayed interaction within internet communication. The inclusion of consituational formants in the contextual model as a part of prognostication of modificational potencies of pertinences in the pentatomic field “speaker – moderator – text – recipient – moderator” allows for a description of communication process in the “downtime” situation as a substantiation of personal pertinence fields into a single relevance field, but also for the algorithmization of deriving generalized content in any indirect delayed discoursive practices. Based on a number of different property classifications, the authors derive a list of criteria features of pertinence and relevance transgression mechanisms. The authors conclude that the transaction of individual components and their introduction into the general space of significance should be accompanied by compliance with certain criteria: interpretation of the horizontal context in a wide field, transmodality, continuality of communicative action, creation of boundary models within the contextualization framework, referential eventfulness, variability of models and their permanent contextual modification, correspondence of models to the horizontal context, complexity of structure and simplification of formal composition, the presence of intersection areas of cognitive assets, the fundamental possibility of significance awareness, context hierarchy, preliminary conventionalization, forecasting the productivity of the applied model, unity of representation patterns, discursive conditionality of meanings, individual and collective alternations of meanings, variability of situations, coherence of discursive moves, mandatory verbalization of consituative components, role hierarchy of particular meanings functionality.

Stage-dependent differential impact of network communication on cognitive function across the continuum of cognitive decline in Parkinson's disease

ObjectiveOur objective was to explore the patterns of resting-state network (RSN) connectivity alterations and investigate how the influences of individual-level network connections on cognition varied across clinical stages without assuming a constant relationship. Methods108 PD patients with continuum of cognitive decline (PD-NC = 46, PD-MCI = 43, PDD = 19) and 34 healthy controls (HCs) underwent resting-state functional MRI and neuropsychological tests. Independent component analysis (ICA) and graph theory analyses (GTA) were employed to explore RSN connection changes. Additionally, stage-dependent differential impact of network communication on cognitive performance were examined using sparse varying coefficient modeling. ResultsCompared to HCs, the dorsal attention network (DAN) and dorsal sensorimotor network (dSMN) were central networks with decreased connections in PD-NC and PD-MCI stage, while the lateral visual network (LVN) emerged as a central network in patients with dementia. Additionally, connectivity of the cerebellum network (CBN) increased in the PD-NC and PD-MCI stages. GTA demonstrated decreased nodal metrics for DAN and dSMN, coupled with an increase for CBN. Moreover, the degree centrality (DC) values of DAN and dSMN exhibited a stage-dependent differential impact on cognitive performance across the continuum of cognitive decline. ConclusionOur findings suggest that across the progression of cognitive impairment, the LVN gradually transitions into a core node with reduced connectivity, while the enhancement of connections in CBN diminishes. Furthermore, the non-linear relationship between the DC values of RSNs and cognitive decline indicates the potential for tailored interventions targeting specific stages.

A Flexible Topology Control Strategy for Mega-Constellations via Inter-Satellite Links Based on Dynamic Link Optimization

In large-scale satellite constellations, the efficiency of inter-satellite communication is paramount. Traditional topology control strategies, such as the Manhattan configuration, provide stable links but can result in indirect communication paths, affecting the efficiency of information transfer. This paper addresses this issue by proposing an innovative “3 + 1” dynamic topology control scheme. The scheme retains three static links determined by the relative angular velocity and acceleration while introducing a dynamic link based on distance and angular velocity constraints to optimize the link duration and overall network communication efficiency. To address the complexity of matching dynamic links, this paper introduces an elite strategy-based maximum weighted matching algorithm for general graphs. Compared to traditional greedy algorithms, our proposed algorithm significantly improves the link duration and topological stability. Through simulation experiments comparing communication delays between Xiamen and Los Angeles, our results show that the proposed dynamic link scheme substantially reduces the average delay, enhancing the efficiency and flexibility of inter-satellite communication. This research not only extends the duration of inter-satellite links but also provides new perspectives and methodologies for further studies on inter-satellite topology control strategies.

Distributed fusion filtering for multi-sensor nonlinear networked systems with multiple fading measurements via stochastic communication protocol

This paper studies the distributed fusion filtering (DFF) issue for a class of nonlinear delayed multi-sensor networked systems (MSNSs) subject to multiple fading measurements (MFMs) under stochastic communication protocol (SCP). The phenomenon of MFMs occurs randomly in the network communication channels and is characterized by a diagonal matrix with certain statistical information. In order to decrease the overload of communication network and save network resources, the SCP that can regulate the information transmission between sensors and estimators is adopted. The primary aim of the tackled problem is to develop the DFF method for nonlinear delayed MSNSs in the presence of MFMs and SCP based on the inverse covariance intersection fusion rule. In addition, the local upper bound (UB) of the filtering error covariance (FEC) is derived and minimized by means of suitably designing the local filter gain. Moreover, the boundedness analysis regarding the local UB is proposed with corresponding theoretical proof. Finally, two simulation examples with comparative illustrations are given to display the usefulness and feasibility of the derived theoretical results.

Performance Landscape: The Relationship between Technology and Society under the Influence of Social Media

In the era of big data, the massive public opinion data on social media has challenged the traditional top-down framework analysis methods. In 2022, Fudan University published the core teaching material of network and new media communication, Computational Public Opinion in the Era of Big Data: Theories, Methods and Cases. In addition to analyzing the challenges faced by the traditional framework theory, the authors Zhou Baohua and Liang Hai also introduce how to use network analysis methods to cope with the transformation of social relations increased by technological progress. The data of CNNIC's 52nd report revealed that China has driven the whole people to go online, and social media is an important carrier for empty-nest youth to fight against weak localization. Therefore, how empty-nest youth use social media to become citizens, localization and family has become a landscape worthy of attention. By using the data of "Investigation on the use of social media by empty Nest Youth" from 2021 to 2023, this paper focuses on the degree of weak localization resistance of social networks and finds that the short video content produced is not only determined by technology or social factors, but a new communication scene jointly constructed by technology and society. In view of the "aphasia" characteristic of the vulnerable groups using social media in the previous research on rural communication, this paper puts forward corresponding countermeasures and suggestions from three perspectives: ideological and political education, intergenerational support and digital inclusion.

Development of Mobile Media Based on Problem-Based Learning in Basic Computer Network Engineering and Communication Subjects

This research aims to develop mobile learning media specifically designed for basic subjects in Computer Network Engineering and Telecommunications to enhance student motivation and learning outcomes. Utilizing the RD (Research and Development) method, the ASSURE model was employed for development. This model includes analyzing learners, stating objectives, selecting instructional methods, media, and materials, utilizing media and materials, requiring learner participation, and evaluating and reinforcing. The mobile media was tested with 36 students from TJKT Vocational High School in Padang. Data collection instruments included validation sheets, practicality questionnaires, student evaluation questions, and student response questionnaires. Results showed a material expert validity of 0.89 and a media expert validity of 0.94, both indicating high validity. Teacher-assessed practicality scored 90.67, while student assessments scored 86.19, both in the very practical category. Effectiveness was determined by student evaluations, with 88.89% of students achieving competency, indicating high effectiveness. The increase in student learning outcomes was significant, with a gain score of 0.74% in the high category. The T-test revealed a significant difference in pretest and posttest learning outcomes (p-value 0.005). In conclusion, the problem-based learning mobile media developed for basic computer network engineering and telecommunications subjects has been validated, deemed practical, and proven effective for learning. Its implementation is expected to boost student engagement, creativity, and learning outcomes, thereby potentially improving the overall quality of education.

Asynchronous Record Alignment of Network Flows for Incident Detection and Reconstruction

In today's interconnected digital landscape, the distribution of cyber threats presents a significant challenge to cyber security. Moreover, as of 2016, the amount of data in the world exceeds one zettabyte. Because of this, evidence-based network flow analytics is a critical component of modern network management and security. Problems such as anomalies in the network flow, cyber security incidents, alert generation, data pre-processing, network monitoring, network flow complexity, and data flow patterns become difficult to detect in massive network data flows. These specific problems can be addressed using Packet capture (PCAP). PCAP analysis is a standard network forensics process and investigation for assessing network behaviour and identifying anomalies. This work presents a method for analysing network flows for probable alignment of asynchronously recorded communications in heterogeneous networks. Using a proposed method for alignment, we can identify the relevant recordings aligned over two data streams for faster and more conclusive incident analysis. We use synthetic network incident scenarios for research experiments, detailing the generation of cyber event data and impact on cloud network traffic, followed by in-depth PCAP analysis. The automated cyber-attacks are simulated within a network infrastructure generating network flows in a PCAP format. Simulated cyber-attacks range from standard port scans, service scans, and specific scenarios like SQL injection, phishing, DoS or DDoS. We define analysis objectives and criteria for the in-depth PCAP analysis and alignment. The evidence gathered showcases valuable information about network data flow and its behaviour.

CDT: Cross-interface Data Transfer scheme for bandwidth-efficient LoRa communications in energy harvesting multi-hop wireless networks

With the capability of generating sustainable energy by exploiting the ambient environment (e.g., light, heat, vibrations, etc.), the energy harvesting (EH) technology is increasingly used on low-power smart objects, forming self-powered green Internet of Things (IoTs). Despite targeting different application domains, many of these green IoT systems adopt the distributed network paradigm by forming energy harvesting multi-hop wireless networks (EH-MWNs). While distributed networks have good scalability during the deployment phase, they are often complex, inelastic to change, and costly to manage. To this end, LoRa, a promising long-range wireless technology, has been suggested for centralized single-hop network controls in EH-MWNs. However, the signal propagation of LoRa is severely affected by the surrounding environment (e.g., obstructions, terrains, etc.), which not only creates a significant difference in packet delivery rate (PDR) between nodes but also increases the bandwidth cost for network controls. To address this issue, we propose a Cross-interface Data Transfer (CDT) scheme, which leverages the ZigBee interfaces coexisting in EH-MWNs to transfer LoRa data traffic from the nodes with a lower PDR to the nodes with a higher PDR for bandwidth-efficient transmissions. By jointly determining the pairs of nodes performing data transfer and the data transfer rates between them, CDT can reduce the overall LoRa bandwidth consumption while ensuring continuous operation of the EH-MWN. A prototype system is implemented by integrating commercial off-the-shelf LoRa and ZigBee interfaces into an IoT platform. Extensive real-world experiments show that under a moderate data traffic input, the bandwidth consumption of CDT is 25.8% and 48.8% lower than the standard LoRaWAN and a state-of-the-art data transfer scheme, respectively. The average energy cost per node is kept as low as 2.29 mW at the same time. Moreover, CDT also shows its performance advantages in terms of PDR and sustainability.

Enabling Technologies for Ultra-Low Latency and High-Reliability Communication in 6G Networks

Enabling Technologies for Ultra-Low Latency and High-Reliability Communication in 6G Networks

Поняття нікнейма: сутність, основні функції

Network name as a primary factor in self-presentation shapes the first impression of the user in the virtual world, becoming an integral component of achieving the set goal. The purpose of this article is to analyze the concept of a nickname, define its essence, highlight characteristic features, and understand its main functions. In particular, the specific character of nickname definitions in lexicographical works and scientific research papers have been studied. It has been determined that contemporary linguistic works actively discuss the issue of internet communication in general and the functioning of linguistic naming units in particular. The revised the following characteristics of nicknames highlighted by the vast majority of researchers have been identified: definition of this concept suggested in the paper is crucial for our research. Moreover, a real or fictional name, a pseudonym, an alias utilized by users for internet communication; the place of use – chats, forums, blogs; the place of communication – the global network, communication on the internet in general. Furthermore, it is important to highlight specific features of nicknames, considering that communication in social networks, chats, forums, and self-presentation in them undergo constant changes. Therefore, this article characterizes the common and distinctive features of a network name and similar onyms as the login name (loginonyms) (presented in computer discourse), an alias, pseudonym, and cryptonym (recognized in onomastics). Common features of a nickname and an alias include the ability to create an unlimited number of onyms for one person, therefore hiding the real identity and modeling a fictional one; as well as non-conventionality of the form and fictionality of the name. Similarly to login names (loginonyms), nicknames are specific types of proper names in the field of Internet communication. Moreover, cryptonym, login name (loginonym), and network name are used in written form. Additionally, the article defines the marking features of network names. Since a nickname is a multifunctional phenomenon, the functional-semantic potential of nicknames is outlined in this scientific research. As a result, it has been revealed that the functions of network names should be categorized depending on the place of their use.

Context-aware resource allocation for vehicle-to-vehicle communications in cellular-V2X networks

Cellular Vehicle-to-Everything (C-V2X) networks provide critical support for intelligently connected vehicles (ICVs) and intelligent transport systems (ITS). C-V2X utilizes vehicle-to-vehicle (V2V) communication technology to exchange safety–critical information among neighbors. V2V communication has stringent high-reliability and low-latency requirements. The existing solutions on resource allocation for V2V communications mainly rely on channel states to optimize resource utilization but fail to consider vehicle safety requirements, which cannot satisfy safety application performance. In this paper, we focus on application-driven channel resource allocation strategy for V2V communications. First, we propose an inter-packet reception model to represent the delay between two consecutive and successful reception packets at a receiver. We then design an application-specific utility function where the utility depends on the packet reception performance and vehicle safety context. Finally, we formulate the channel resource allocation problem as a non-cooperative game model. The game model can guide each node to cooperate and achieve the trade-off between fairness and efficiency in channel resource allocation. The simulation results show that our work can significantly improve the reliability of V2V communications and guarantee the vehicle safety application performance.

Семья в информационной культуре: проблема детско-родительских отношений

The family has been a cornerstone of human society throughout history, serving as the primary institution for raising children, passing down cultural values, and providing emotional support. This article explores the trends and contradictions in the development of family culture and familyhood in the information society of our time. It notes that the intensive development of virtual network communication and the acceleration of the pace of life are factors leading to profound changes in generational identity. The traditional format of the ethical structure of intra-family interaction between adults and children is undergoing significant transformations. The author considers the acquisition by parents and children of autonomous socio-cultural status and meaning to be conditioned by the period of the emergence of an industrial urban civilization. In the information society, there is a diffusion of boundaries between childhood and adulthood, which influences the value perception of the family by the younger generation. The author identifies issues in parent-child relationships that need to be overcome in the further development of the information and digital environment.

Enhancing UAV‐HetNet security through functional encryption framework

SummaryIn the current landscape, the rapid expansion of the internet has brought about a corresponding surge in the number of data consumers. As user volume and diversity have escalated, the shift from conventional, uniform networks to Heterogeneous Networks (HetNets) has emerged. HetNets are designed with a primary objective: enhancing Quality of Service (QoS) standards for users. In the context of HetNets facilitated by Unmanned Aerial Vehicles (UAVs), a substantial influx of users and devices is observed. Within this multifaceted environment, the potential for malicious intruder nodes to efficiently execute and propagate harmful actions across the network is a distinct concern. Consequently, the entirety of network communication becomes susceptible to a multitude of security threats. To address these vulnerabilities and safeguard communication, the Functional Encryption (FE) technique is employed. FE empowers the protection of data against intrusion attacks. This paper presents a comprehensive methodology for implementing FE within UAV‐integrated HetNets, executed in two sequential phases. The initial phase secures communication between User Equipment (UE) and Micro Base Station (MBS), followed by the second phase, which focuses on securing communication among MBS and UAV. The viability of the proposed approach is substantiated through validation using the Automated Validation of Internet Security Protocols and Applications (AVISPA) tool. The validation process involves the development of High‐Level Protocol Specification Language (HLPSL) codes. The successful security validation outcome underscores the capacity of the proposed methodology to provide the intended security measures and robustness to the network environment.

A hybrid CNN-GRU-based intrusion detection system for secure communication in vehicular adhoc network

ABSTRACT Vehicular Ad hoc Network (VANET) is a component of the Intelligent Transportation System (ITS) which furnishes communication among vehicles. It delivers comfort and safety information to passengers and vehicle drivers. Security plays a vital role during the transmission of data as the various distinct security attacks directly influence the safety of the passengers on the road. Several security attacks will disrupt normal functions like the transmission of data. Some security breaches inject false information which affects the safety of drivers. However, there are several demurrers in detecting abnormal activities efficiently as the traditional system faces imbalanced data problems. This paper presents an Intrusion Detection System (IDS) for detecting anomalies and protecting communication systems from several distinct attacks. The proposed IDS utilizes two deep learning (DL) mechanisms such as Convolutional Neural Network (CNN) and Gated Recurrent Unit (GRU) for detecting anomalies in the vehicular network. The hybrid CNN-GRU mechanism helps in solving the overfitting and low-velocity problems. It also detects several attacks and protects the ad hoc network from those attacks to safeguard the vehicle users. The results show that the propounded model outperforms the other traditional detection mechanisms by 10.79% in terms of performance compared to other IDS.

On-chip silicon photonic micro-ring processor lights up optical image encryption.

Optical image encryption has long been an important concept in the fields of photonic network processing and communication. Here, we propose a convolution-like operation-based optical image encryption algorithm exploiting a silicon photonic multiplexing architecture to achieve content security. Particularly, the encryption process is completed in a 3 × 3 cross-shaped photonic micro-ring resonator (MRR) array on chip. For the first time, to the best of our knowledge, this algorithm encodes information in an integrated intensity modulation, effectively reducing the encoding difficulty. Moreover, the high reliability and scalability of optical encryption are ensured using both linear and nonlinear operations on photonic chips according to characteristics of MRRs. As the encryption and decryption experiments show, the image restoration accuracy of our optical encryption algorithm exceeds 99% under real system noise at the pixel level, indicating its noise-robust property. Meanwhile, the peak signal-to-noise ratios of the restored and encrypted images are >60 and <15 dB, respectively, revealing both the high accuracy of the restored image and the small correlation between the encrypted and original images. This work adds to the rapidly expanding field of optical image encryption on photonic chips.

Secure Encrypted Transmission of Network Data in Cloud Computing Technology Environment

In order to solve the problem of communication data theft in conventional network communication data transmission methods and ensure the security of network communication data transmission, it is necessary to design new network communication data security transmission methods based on cloud computing technology, formulate network communication data security transmission agreements, construct a network communication data security transmission model based on cloud computing technology, and design a network communication data security transmission scheme, implement secure transmission of network communication data. The experimental results show that after using the designed network communication data secure transmission method, the amount of stolen communication data is less than that of conventional methods. This proves that the designed network communication data secure transmission method has high transmission security, good transmission effect, and reliability, and can be used as a reference for subsequent network communication data encryption transmission.

CYBER CRIME CYBERSTALKING THROUGH THE CYBER LAW FORENSIC SCIENCE AND CRIMINAL INVESTIGATION

As it is well known, the usage of the internet and mobile phones has entirely turned this world into a virtual one. In this virtual setting, Pandemic 2020 offers a fresh viewpoint on human existence. IT now serves as a crucial organ for survival. Not only has information technology expanded the sphere of development, but it has also turned into an axis for global development. People may quickly and easily access a variety of information in the virtual world. However, everything has two sides, just like a coin, and the development of information technology has sped up the growth of cybercrime everywhere. Cyber stalking is the act of following someone using a computer or other device connected to one, which can instil terror in the victim. A relatively modern form of cybercrime is cyber stalking. The study focuses about the meaning, nature, typology and history of cyber stalking.. This thesis compares the law relating to cyber stalking in India with different foreign countries. This thesis also discussed about the reported cases of cyber stalking from 2017-2020 as per the data of NCRB. Reason and effect of cyber staling has also been discussed in this study. Scholar suggests that there is the need of amendment of current laws specifically for the gender neutral laws and law which add the issues of international jurisdiction. Study also suggest that self-awareness is also needed for safeguard ourselves from such crimes. Digital technology is encompassing in all walks of life, all over the world and has brought the real meaning of globalization. At the one end cyber system provides opportunities to communicate and at the other end some individuals or community exploit its power for criminal purposes. Criminals exploit the Internet and other network communications which are international in scope. Situation is alarming; Cybercrime is an upcoming and is talk of the town in every field of the society/system. Theoretically and practically this is a new subject for researchers and is growing exponentially. Lot of work has been done and endless has to be go because the invention or up gradation of new technology leads to the technical crime i.e. the digital or we can say the cybercrime or e-crime. This is because every day a new technique is being developed for doing the cybercrime and many times, we are not having the proper investigating method/model/technique to tackle that newly cybercrime. Cybercrime is a criminal activity in which computers or computer networks are used as a tool, a target, or a place of criminal activity and includes everything from electronic cracking to denial of service attacks. It is also used to include traditional crimes in which computers or networks are used to enable the illicit activity.