Deep Learning Social Network Access Control Model Based on User Preferences

A deep learning access controlmodel based on user preferences is proposed to address the issue of personal privacy leakage in social networks.Firstly,socialusers andsocialdata entities are extractedfromthe social networkandused to construct homogeneous and heterogeneous graphs.Secondly,a graph neural networkmodel is designed based on user daily social behavior and daily social data to simulate the dissemination and changes of user social preferences and user personal preferences in the social network.Then,high-order neighbor nodes,hidden neighbor nodes,displayed neighbor nodes,and social data nodes are used to update user nodes to expand the depth and breadth of user preferences.Finally,a multi-layer attention network is used to classify user nodes in the homogeneous graph into two classes:allow access and deny access.The fine-grained access control problem in social networks is transformed into a node classification problem in a graph neural network.The model is validated using a dataset and compared with other methods without losing generality.The model improved accuracy by 2.18%compared to the baseline method GraphSAGE,and improved F1 score by 1.45%compared to the baseline method,verifying the effectiveness of the model.

Virus spreading in wireless sensor networks with a medium access control mechanism

In this paper, an extended version of standard susceptible-infected （SI） model is proposed to consider the influence of a medium access control mechanism on virus spreading in wireless sensor networks. Theoretical analysis shows that the medium access control mechanism obviously reduces the density of infected nodes in the networks, which has been ignored in previous studies. It is also found that by increasing the network node density or node communication radius greatly increases the number of infected nodes. The theoretical results are confirmed by numerical simulations.

Joint Resource Allocation and Admission Control in Sliced Fog Radio Access Networks

Network slicing based fog radio access network(F-RAN) has emerged as a promising architecture to support various novel applications in 5 G-and-beyond wireless networks. However, the co-existence of multiple network slices in F-RANs may lead to significant performance degradation due to the resource competitions among different network slices. In this paper, the downlink F-RANs with a hotspot slice and an Internet of Things(Io T) slice are considered, in which the user equipments(UEs) of different slices share the same spectrum. A novel joint resource allocation and admission control scheme is developed to maximize the number of UEs in the hotspot slice that can be supported with desired quality-of-service, while satisfying the interference constraint of the UEs in the Io T slice. Specifically, the admission control and beamforming vector optimization are performed in the hotspot slice to maximize the number of admitted UEs, while the joint sub-channel and power allocation is performed in the Io T slice to maximize the capability of the UEs in the Io T slice tolerating the interference from the hotspot slice. Numerical results show that our proposed scheme can effectively boost the number of UEs in the hotspot slice compared to the existing baselines.

Interference management via access control and mobility prediction in two-tier heterogeneous networks

Abstract： Two-tier heterogeneous networks （HetNets）, where the current cellular networks, i.e., macrocells, are overlapped with a large number of randomly distributed femtocells, can potentially bring significant benefits to spectral utilization and system capacity. The interference management and access control for open and closed femtocells in two-tier HetNets were focused. The contributions consist of two parts. Firstly, in order to reduce the uplink interference caused by MUEs （macrocell user equipments） at closed femtocells, an incentive mechanism to implement interference mitigation was proposed. It encourages femtoeells that work with closed-subscriber-group （CSG） to allow the interfering MUEs access in but only via uplink, which can reduce the interference significantly and also benefit the marco-tier. The interference issue was then studied in open-subscriber-group （OSG） femtocells from the perspective of handover and mobility prediction. Inbound handover provides an alternative solution for open femtocells when interference turns up, while this accompanies with PCI （physical cell identity） confusion during inbound handover. To reduce the PCI confusion, a dynamic PCI allocation scheme was proposed, by which the high handin femtocells have the dedicated PCI while the others share the reuse PCIs. A Markov chain based mobility prediction algorithm was designed to decide whether the femtoeell status is with high handover requests. Numerical analysis reveals that the UL interference is managed well for the CSG femtocell and the PCI confusion issue is mitigated greatly in OSG femtocell compared to the conventional approaches.

DNBP-CCA:A Novel Approach to Enhancing Heterogeneous Data Traffic and Reliable Data Transmission for Body Area Network

The increased adoption of Internet of Medical Things (IoMT) technologies has resulted in the widespread use ofBody Area Networks (BANs) in medical and non-medical domains. However, the performance of IEEE 802.15.4-based BANs is impacted by challenges related to heterogeneous data traffic requirements among nodes, includingcontention during finite backoff periods, association delays, and traffic channel access through clear channelassessment (CCA) algorithms. These challenges lead to increased packet collisions, queuing delays, retransmissions,and the neglect of critical traffic, thereby hindering performance indicators such as throughput, packet deliveryratio, packet drop rate, and packet delay. Therefore, we propose Dynamic Next Backoff Period and Clear ChannelAssessment (DNBP-CCA) schemes to address these issues. The DNBP-CCA schemes leverage a combination ofthe Dynamic Next Backoff Period (DNBP) scheme and the Dynamic Next Clear Channel Assessment (DNCCA)scheme. The DNBP scheme employs a fuzzy Takagi, Sugeno, and Kang (TSK) model’s inference system toquantitatively analyze backoff exponent, channel clearance, collision ratio, and data rate as input parameters. Onthe other hand, the DNCCA scheme dynamically adapts the CCA process based on requested data transmission tothe coordinator, considering input parameters such as buffer status ratio and acknowledgement ratio. As a result,simulations demonstrate that our proposed schemes are better than some existing representative approaches andenhance data transmission, reduce node collisions, improve average throughput, and packet delivery ratio, anddecrease average packet drop rate and packet delay.

Distributed multichannel medium access control protocol without common control channel for single-hop cognitive radio networks

A novel distributed cognitive radio multichannel medium access protocol without common control channel was proposed.The protocol divided a transmission interval into two parts for exchanging control information and data,respectively.In addition to evaluating system saturation throughput of the proposed protocol,a three-dimensional multi channel Markov chain model to describe the sate of the cognitive users (CUs) in dynamic spectrum access was presented.The proposed analysis was applied to the packet transmission schemes employed by the basic,RTS/CTS access mechanism adopted in the normal IEEE 802.11.Analyzing the advantage of the two methods,a hybrid access mechanism was proposed to improve the system throughput.The simulation results show that the experiment results are close to the value computed by the model (less than 5%),and the proposed protocol significantly improves the performance of the system throughput by borrowing the licensed spectrum.By analyzing the dependence of throughput on system parameters,hybrid mechanism dynamically selecting access mechanism can maintain high throughput.

A Media Access Control Scheme for Service Differentiation in Ad hoc Networks

IEEE 802.11 distributed coordination function(DCF)can alleviate the collision and hidden station problem,but it doesn't differentiate traffic categories(TC).Therefore,it can't provide sufficient quality of service(QoS)support for different TC.Recently,a new contention-based enhanced distributed channel access(EDCA)scheme is proposed which provides a probabilistic QoS support.In this paper,an improved EDCA scheme for service differentiation in ad hoc networks is proposed.In this scheme,signal channel resistance coefficient is used to adjust the contention window(CW).It proves that the scheme provides the traffic differentiation,high throughput and low delay through simulation.

Mobility Conscious Medium Access Control Scheme for Wireless Sensor Networks: A Conceptual Approach

Mobility in Wireless Sensor Network (WSN) presents distinctive challenges in Medium Access Control (MAC) scheme. Numerous MAC protocols for sensor networks assume that sensor nodes are static and focus primarily on energy efficiency. This work seeks to develop an improved mobility conscious medium access control scheme for wireless sensor networks with a view to enhance energy conservation on mobile sensor nodes. On this note, mobility patterns of different scenarios are modelled using Gauss Markov Mobility Model (GMMM) to determine the position and distance of the sensor nodes and how they are correlated in time.

Fault detection for networked systems subject to access constraints and packet dropouts

This paper addresses the problem of fault detection（FD） for networked systems with access constraints and packet dropouts.Two independent Markov chains are used to describe the sequences of channels which are available for communication at an instant and the packet dropout process,respectively.Performance indexes H∞ and H_ are introduced to describe the robustness of residual against external disturbances and sensitivity of residual to faults,respectively.By using a mode-dependent fault detection filter（FDF） as residual generator,the addressed FD problem is converted into an auxiliary filter design problem with the above index constraints.A sufficient condition for the existence of the FDF is derived in terms of certain linear matrix inequalities（LMIs）.When these LMIs are feasible,the explicit expression of the desired FDF can also be characterized.A numerical example is exploited to show the usefulness of the proposed results.

An application-layer based centralized information access control for VPN

With the rapid development of Virtual Private Network (VPN), many companies and organizations use VPN to implement their private communication. Traditionally, VPN uses security protocols to protect the confidentiality of data, the message integrity and the endpoint authentication. One core technique of VPN is tunneling, by which clients can access the in- ternal servers traversing VPN. However, the tunneling technique also introduces a concealed security hole. It is possible that if one vicious user can establish tunneling by the VPN server, he can compromise the internal servers behind the VPN server. So this paper presents a novel Application-layer based Centralized Information Access Control (ACIAC) for VPN to solve this problem. To implement an efficient, flexible and multi-decision access control model, we present two key techniques to ACIAC—the centralized management mechanism and the stream-based access control. Firstly, we implement the information center and the constraints/events center for ACIAC. By the two centers, we can provide an abstract access control mechanism, and the material access control can be decided dynamically by the ACIAC’s constraint/event mechanism. Then we logically classify the VPN communication traffic into the access stream and the data stream so that we can tightly couple the features of VPN communication with the access control model. We also provide the design of our ACIAC prototype in this paper.

Predictive Decision and Reliable Accessing for UAV Communication in Space-Air-Ground Integrated Networks

The cooperation of multiple Unmanned Aerial Vehicles(UAVs) has become a promising scenario in Space-Air-Ground Integrated Networks(SAGINs) recently due to their widespread applications,where wireless communication is a basic necessity and is normally categorized into control and nonpayload communication(CNPC) as well as payload communication. In this paper, we attempt to tackle two challenges of UAV communication respectively on establishing reliable CNPC links against the high mobility of UAVs as well as changeable communication conditions, and on offering dynamic resource optimization for Quality-of-Service(QoS) guaranteed payload communication with variable link connectivity. Firstly, we propose the concept of air controlling center(ACC), a virtual application equipped on the infrastructure in SAGINs, which can collect global information for estimating UAV trajectory and communication channels. We then introduce the knapsack problem for modelling resource optimization of UAV communication in order to provide optimal access points for both CNPC and payload communication. Meanwhile, using the air controlling information, predictive decision algorithm and handover strategy are introduced for the reliable connection with multiple access points. Simulation results demonstrate that our proposal ensures an approximate always-on reliable accessing of communication links and outperforms the existing methods against high mobility,sparse distribution, and physical obstacles.

Performance Analysis of WLAN Medium Access Control Protocols in Simulcast Radio-Over-Fiber-Based Distributed Antenna Systems

The performance of three wireless local-area network(WLAN) media access control(MAC) protocols is investigated and compared in the context of simulcast radioover-fiber-based distributed antenna systems(RoF-DASs) where multiple remote antenna units(RAUs) are connected to one access point(AP) with different-length fiber links.The three WLAN MAC protocols under investigation are distributed coordination function(DCF) in basic access mode,DCF in request/clear to send(RTS/CTS) exchange mode,and point coordination function(PCF).In the analysis,the inter-RAU hidden nodes problems and fiber-length difference effect are both taken into account.Results show that adaptive PCF mechanism has better throughput performances than the other two DCF modes,especially when the inserted fiber length is short.

Architectural Approaches to Network and Service Access Authentication

Authentication is the first step,of central importance, for access control and for security protection in radio access networks.A general model for authentication was adopted from fixed networks and applied to the wireless world.However,the differences in the operational environment between the fixed and the wireless world,heterogeneity of the radio communications systems,new trends in service provisioning, emerging business models and performance requirements raise the need to revisit the original requirements for authentication systems and to come up with schemes that better suit current needs.In this review paper we discuss authentication in singlehop radio access networks by characterizing the current as well as the emerging authentication schemes.

AN ADAPTIVE OPPORTUNISTIC RETRANSMISSION CONTROL SCHEME ENVIRONMENT-AWARE-BASED FOR WIRELESS MULTIMEDIA MESH NETWORKS

In this paper, we propose an aware-based adaptive opportunistic retransmission control scheme for wireless multimedia Mesh networks. The proposed scheme provides maximum retransmis-sion count optimization based on environment-aware to improve packet relay probability. The scheme discriminates the types of packet loss in wireless link by means of environment information and selects the retransmission count by taking the IEEE 802.11 wireless channel characteristics into consideration. Furthermore, the maximum retransmission count of MAC is adjusted adaptively. Extensive simulations demonstrate that the proposed scheme significantly reduces packet collision probability and packet loss rate, and thus improves network throughput.

User-Based Discrete-Time Queuing Analysis for Opportunistic Spectrum Access in Cognitive Radio Networks

In cognitive radio networks, the spectrum utilization can be improved by cognitive users opportunistically using the idle channels licensed to the primary users. However, the new arrived cognitive users may not be able to use the channel immediately since the channel usage state is random. This will impose additional time delay for the cognitive users. Excessive waiting delay can make cognitive users miss the spectrum access chances. In this paper, a discrete-time Markov queuing model from a macro point of view is provided. Through the matrix-geometric solution theory, the average sojourn time for cognitive users in the steady state before accessing the spectrum is obtained. Given the tolerant delay of cognitive users, the macro-based throughput is derived and an access control mechanism is proposed. The numerical results show the effects of service completion probability on average sojourn time and throughput. It is confirmed that the throughput can be obviously improved by using the proposed access control mechanism. Finally, the performance evaluations based on users are compared to that based on data packets.

Access Control Policy Based on Friend Circle

Nowadays,the scale of the user’s personal social network(personal network,a network of the user and their friends,where the user we call“center user”)is becoming larger and more complex.It is difficult to find a suitable way to manage them automatically.In order to solve this problem,we propose an access control model for social network to protect the privacy of the central users,which achieves the access control accurately and automatically.Based on the hybrid friend circle detection algorithm,we consider the aspects of direct judgment,indirect trust judgment and malicious users,a set of multi-angle control method which could be adapted to the social network environment is proposed.Finally,we propose the solution to the possible conflict of rights in the right control,and assign the rights reasonably in the case of guaranteeing the privacy of the users.

A DUAL RESERVATION CDMA-BASED MAC PROTOCOL WITH POWER CONTROL FOR AD HOC NETWORKS

This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided into common channel,broadcast channel and several data chan-nels. And dynamic power control mechanism is implemented to reduce near-far interference. Compared with IEEE 802.11 Distributed Coordination Function (DCF) protocol,the results show that the pro-posed mechanism improves the average throughput and limits the transmission delay efficiently.

DQCA:a New Medium Access Control Protocol for MANs

A new medium access control protocol for MANs named DQCA(Distributed QueueCyclic Access)is presented in this paper.When the users of DQCA MAN transfer long files,the network will reach a steady state which is fair after a transient period.The transient pe-riod is shorter than that of DQDB.DQCA MAN has the flexibility in bandwidth allocation:the users can achieve different throughputs if the parameters,Pmax(i),are set to be differ-ent.The implementation of priority mechanism is simpler than that of DQDB.