User-centric Access Research Articles

User-Centric Access Network (UCAN) for 6G: Motivation, Concept, Challenges and Key Technologies

A universal and flexible network architecture is required to meet the demands for optimal user experience and all coverage types including wide area coverage and ultra-dense coverage in 6G. In this paper, a powerful network architecture, the user-centric access network (UCAN), is proposed to meet the multi-dimensional demands of 6G. After analyzing the motivations and requirements, we introduce the concept, architecture, and networking scenarios of UCAN. UCAN has four distinct features including deeply customized network, elastic reconfigurable network, open and compatible network, and intelligent adaptive network for user services. In deployment, flexible cell can be constructed and updated for a user with the suitable surrounding access points. The challenges and corresponding key technologies to achieve UCAN are then illustrated to include user-centric access and connection management, dynamic AP management, unified management of interference and resource, and lightweight security. Then a simulation result is given to verify the effectiveness of UCAN. Finally, future works are discussed to indicate the research directions for academia and industry.

Efficient Privacy-Friendly and Flexible Wearable Data Processing With User-Centric Access Control

Efficient Privacy-Friendly and Flexible Wearable Data Processing With User-Centric Access Control

Beamforming Design in Short-Packet Transmission for URLLC in Cell-Free Massive MIMO System

Low latency, high reliability, and high data rate are three performance indicators of Ultra-reliable and low latency communication (URLLC) systems, but they are not able to be met simultaneously. Based on the determined latency and reliability requirements, this paper investigates the problem of the weighted sum rate (WSR) in cell-free massive multi-input multi-output (MIMO) system with multiple access points (APs). User-centric access point selection is considered to further reduce the computational complexity for AP used with acceptable performance loss. The transmitting beamforming is designed to mitigate inter-user interference so as to maximize the WSR under the backhaul and transmitting power constraints. Since the proposed problem is non-convex, two algorithms are proposed to solve the problem under the general SINR regime and the high SINR regime, respectively. For the former, we first approximate the objective function with the difference of convex (DC) programming and reformulate the problem into a semi-definite relaxation (SDR) form. Afterward, auxiliary variables are introduced in accordance with the successive convex approximation (SCA) method to further transform the nonconvex problem into a convex one. In the end, the sub-optimal WSR is obtained by iteratively solving a final convex problem. For the latter, the well-known WMMSE method is applied to address the WSR problem. Numerical results demonstrate the efficiency of our proposed algorithm, e.g., the maximum performance gain of the proposed algorithm is about 25% compared to the classical MMSE method. And the user-centric approach achieves 8 times computational complexity reduction with 4% performance loss.

Applying staged event-driven access control to combat ransomware

The advancement of modern Operating Systems (OSs), and the popularity of personal computing devices with Internet connectivity, have facilitated the proliferation of ransomware attacks. Ransomware has evolved from executable programs encrypting user files, to novel attack vectors including fileless command scripts, information exfiltration and human-operated ransomware. Many anti-ransomware studies have been published, but many of them assumed newer ransomware variants only performed file encryption, were similar to existing variants, and often did not consider those novel attack vectors. We have defined an updated ransomware threat model to include those novel attack vectors, and redefined false positives and false negatives in the context of ransomware mitigation. We proposed to apply both program-centric and user-centric access control to combat ransomware, but only delegate access control decisions that users are capable of making to users, while enforcing non-negotiable access control decisions by OS and software developers. We have designed a Staged Event-Driven Access Control (SEDAC) approach to incorporate both program-centric and user-centric access control measures, and demonstrated a prototype on Windows OS. Our prototype was able to intercept more types of ransomware attack vectors than existing proposals. We hope to convince OS and software architects to incorporate our design to better combat ransomware.

User-Centric Access Point Selection in Cell-Free Massive MIMO Systems: A Game-Theoretic Approach

In this letter, we investigate user-centric access point (AP) selection for cell-free massive multiple-input multiple-output (MIMO) systems. In contrast to existing works, we study this problem from the perspective of game theory and model user-centric AP service cluster formation as a local altruistic game, which is proven to be an exact potential game (EPG) and to have at least one pure Nash equilibrium (NE). Then, an improved maximum non-neighbor-set-based concurrent spatial adaptive play (MNSB-C-SAP) algorithm is proposed to achieve the NE. Simulation results show that the proposed algorithm outperforms existing algorithms in terms of convergence speed and verify the superiority of the game-theoretic AP selection method compared with some existing approaches.

GAN for Load Estimation and Traffic-Aware Network Selection for 5G Terminals

In the face of the user-centric access network architecture adopted by the fifth-generation (5G) mobile communication network terminals, the communication capability of terminals faces significant challenges. In this case, the combination of 5G and artificial intelligence (AI) has become a significant trend to meet the various communication needs of terminal devices. Toward the problem that the data analysis and decision making for cell load estimation are primarily accomplished on the access side of the network, terminals can only passively access the network, but cannot predict the load estimation on the access side of the network in advance and cannot make network selection decisions in real time. In this article, we propose a cell load estimation algorithm based on a generative adversarial network (GAN) for 5G mobile communication networks, which considers estimating the cell load according to the wireless information measured by the terminals. The algorithm effectively estimates the cell load at the terminal side, which reflects the intelligence of the terminals and solves the problems of low data transmission rate, high signaling cost, and time delay in the existing techniques for load estimation schemes at the network side, assisting users in making a real-time decision. The performance is evaluated through the system-level simulation, and the results indicate that the proposed model improves load estimation accuracy, simultaneously improving the network throughput and reducing the packet queuing delay, suitable for different heterogeneous network scenarios.

An Efficient Blockchain Based Data Access with Modified Hierarchical Attribute Access Structure with CP-ABE Using ECC Scheme for Patient Health Record

Secure patient health record (PHR) information exchange via cloud computing is a considerable security risk to user privacy. The fundamental reason of this issue is cloud computing’s reliance on trustworthy third parties to share data across it. To exchange data securely, many conventional cryptographic algorithms employ various keying approaches. However, relying on a trusted third party compromises the privacy of consumers’ data. To offer secure communication without the involvement of a third party, a distributed blockchain based (DBC) ciphertext–policy attribute-based encryption (CP-ABE) approach is employed in this study. Because of bilinear paring and simple scalar multiplication factors, the proposed CP-ABE system is entirely dependent on elliptic curve cryptography to reduce complexity. Furthermore, the data requester provides dynamic attributes, and a user-centric access policy is created, allowing multiple authorities to manage the attributes and provide data access. Data confidentiality, data authentication, user authentication, and tamper-proof data are all guaranteed by the suggested method. The DBC-CP-ABE method is used to provide user-centric access policies and effective key management.

Dynamic user-centric access control for detection of ransomware attacks

Ransomware attacks are often catastrophic, yet existing reactive and preventative measures could only partially mitigate ransomware damage, often not in a timely manner, and often cannot prevent the novel attack vectors. Many of them were program-centric or data-centric and did not take into consideration user intention or consent. In this paper, we advocate for a dynamic approach of detecting ransomware-like behaviors by proposing a user-centric access control framework, which collects security indicators from the Operating System (OS) to deduct security metrics, compute security indicators and estimate security positions, to dynamically make access control assessments on file access requests. To demonstrate its applicability, we effectuated the principles of User-Driven Access Control (UDAC) for user intention (the goal of a user operation) and Content-Based Isolation (CBI) for user consent (the acceptance of the consequence of a user operation), and developed a proof-of-concept prototype on Windows desktop platforms. It collected information that could reveal the application identity, behavior and the OS environmental factor, before assessing whether an access request to the file system violated the principles of UDAC or CBI. Our prototype was able to raise early warnings on both attacks by real and simulated ransomware of novel vectors.

On the optimal energy efficiency and spectral efficiency trade-off of CF massive MIMO SWIPT system

Energy efficiency is a key requirement for future network design, and user-centric (UC) cell-free (CF) massive multi-input multi-output (MIMO) networks can achieve over ten times the energy efficiency. Based on this, this paper studies a CF MIMO simultaneous wireless information and power transmission system and proposes a UC access point (AP) selection method and a trade-off performance optimization scheme for spectral efficiency and energy efficiency. In this system, users have both energy recovery and information transmission functions. According to the difference between the interference in the energy harvesting and information transmission process, a flexible AP selection scheme is designed. Blindly pursuing high spectral efficiency will result in waste of resources. This paper proposes an evaluation index that takes into account both energy efficiency and spectral efficiency, analyses the trade-off between energy efficiency and spectral efficiency, and jointly optimizes the AP selection scheme and the uplink (UL) and downlink (DL) time switching ratio to maximize the trade-off performance. Then, the non-convex problem is converted to a geometric planning problem to solve. The simulation results show that by implementing a suitable AP selection scheme and UL and DL time allocation, the information processing scheme on the AP side has a slight loss in spectral efficiency, but the energy efficiency is close to the performance of global processing on the central processing unit.

Toward more user-centric data access solutions: Producing synthetic data of high analytical value by data synthesis1

Under the Modernization programme Statistics Canada has recently undertaken, the Agency is to put forward data access solutions that present greater analytical value to Canadians while maintaining its core values of protecting confidentiality of respondents’ information. One avenue currently explored is Data Synthesis as a means of delivering synthetic data with high analytical value to users. At the time of writing, Statistics Canada has publicly released synthetic versions of two different datasets related to census, mortality and cancer information. In both cases, synthetic data were generated using the R package synthpop. This paper describes the use of Data Synthesis as a proof of concept for modernizing Statistics Canada’s data access solutions.

User-Centric Access Scheme Based on Interference Management for Indoor VLC-WIFI Heterogeneous Networks

VLC-WIFI heterogeneous networks have become a promising solution, where VLC and WIFI are collaborating on providing services for indoor users. The dense deployment of visible light communication multiple access points (APs) can expand the system capacity, but it leads to complicated inter-cell interference (ICI). In order to arrange users to access the appropriate AP and implement interference management, a novel scheme called user-centric access based on regular spectrum allocation (UCARSA) is proposed in the paper. In UCARSA, the sliced visible spectrum is assigned to VLC APs regularly, so that the user associated with more than one AP is impacted less by ICI. Furthermore, the virtual community is constructed for each user to balance the user rate and improve the average spectral efficiency. The above performance improvement can be proved by simulation results in this paper, and it shows that the performance of UCARSA is better than two kinds of comparison algorithms.

Kinematic Information Aided User-Centric 5G Vehicular Networks in Support of Cooperative Perception for Automated Driving

The cooperative perception of the driving environment via the sharing of locally sensed information among automated vehicles plays a fundamental role in ensuring the basic safety of automated driving in complicated public traffic. However, demanding requirements ranging from high data rate and large user density to ultra-high reliability and low latency, are imposed on the 5G network, which is considered the key enabler of cooperative automated driving. In this paper, we propose a novel ultra-dense 5G vehicular network architecture, which features the kinematic information aided user-centric access, to address these requirements. In particular, distributed local access and application centers (LAACs) are designed to perform application implementation and access control collectively, such that the kinematic information of the vehicles extracted at the application layer can be exploited in the dynamic management of network resources to sustain consistently high-performance wireless communications between vehicles and their serving LAACs. Focusing on the uplink transmission of the periodic cooperative sensing messages (CSMs), the possible design of key elements in the kinematic information aided user-centric access, including access point association, radio resource allocation, and mobility support, are discussed. Issues brought about by the practical network deployment and constraints are also considered. In addition, a practical benchmarking access strategy set, which addresses both the reliability and the latency requirements of CSMs, is proposed and evaluated by simulation under the freeway and intersection scenarios.

User-Centric Multi-RATs Coordination for 5G Heterogeneous Ultra-Dense Networks

This column reviews the concept of user-centric access, which permits the network to tailor a “follow me” virtual cell for a user via multipoint coordination in a UDN environment. We further discuss the feasibility of extending such a virtual cell by considering tight integration of heterogeneous RATs exposed to the user, by taking the context information and instantaneous status of the user device into account. In particular, we conceive an edge/fog computing platform capable of acquiring and jointly processing information from multiple heterogeneous RATs and the users. Such a framework may have great potential to play key roles in 5G and beyond, in terms of realizing truly flexible radio access that can be customized for each individual user in the network.

One-Time-Username: A Threshold-based Authentication System

Due to the complexity and volume, memorizing static usernames and passwords is deemed to be one of the most cumbersome tasks for ordinary users. Nevertheless, verifying the access legitimacy of a user without using a verification table and securely granting permissions based on an access control policy assigned to the user are two critical challenges to build an authentication scheme which is practical and effective. Traditional approaches either completely ignore the importance of user-centric access control or rely on a single point of verification or a third party authority; but in practice, access control and distributed verifiers are important for enhancing security and dealing with the dynamics caused by the user online browsing activities. In this paper, we propose a threshold-based authentication system leveraging user computing devices and allowing users to designate various permissions. Various (t,n) physical or virtual devices can participate to run an authentication protocol and provide the user with a one-time credential to access an online banking system. Our evaluation and results show that the solution is not only practical, but it also minimizes the risks associated with traditional approaches.

Grouping and Cooperating Among Access Points in User-Centric Ultra-Dense Networks With Non-Orthogonal Multiple Access

A user-centric ultra-dense network (UUDN) is proposed as one of the promising solutions to provide very high area throughput density and flexible access service for users in the fifth-generation systems. On the one hand, network densification provides opportunities to cooperate among a large number of access points (APs) for serving a given user. On the other hand, the limited radio resources cause the serious competition among numerous APs and may degrade the network performance. Therefore, to support large number of connections and break through the restriction of limited frequency resource, non-orthogonal multiple access (NOMA), which supports multiple signals to transmit on the same frequency resource, is introduced into the UUDN. However, NOMA with network densification arises a series of challenges. And the method to group APs efficiently on the same frequency to support for a given user is a critical problem. Thus, in this paper, we propose a user-centric access framework for providing efficient access service and the flexible resource management in NOMA-based UUDN. Under the proposed framework, we then investigate the access scheme that organizes multiple APs into respective AP group (APG) cooperatively to provide access service for each user, aiming at maximizing the system energy efficiency. First, considering the users’ requirement and network environment, a grouping evaluation model is set up to organize APG efficiently. Then, we formulate the resource allocation problem of APG as a mix-integer non-linear programming problem, which is hard to tackle. For tractability purpose, we transform this problem and propose low-complexity algorithms based on matching and differ of convex programming theories to obtain a feasible solution. Extensive simulation results are presented to demonstrate the significant performance improvement compared with the existing schemes.

User-Centric Access Control for Android Platform

대표적 모바일 플랫폼인 안드로이드에서는 접근 제어를 위해 권한 모델을 사용하고 있지만 관련된 몇 가지 취약성들이 알려졌다. 이를 개선하기 위한 몇 가지 방식이 제안되었으며, 애플리케이션 단위에서 각각의 권한에 대한 제어를 수행하는 방식이었다. 하지만 이 방식은 많은 애플리케이션들을 관리하기에는 매우 복잡하며 연계된 공격을 제어하기도 힘들었다. 이를 개선하기 위해 본 논문에서는 사용자가 직접 보안 정책을 수립하고 이 정책이 개별 애플리케이션이 아닌 전체에 적용되는 사용자 중심의 접근 제어 시스템을 제안한다. 그리고 제안 시스템의 동작에 대한 검증을 수행하고 제안 시스템으로 인한 성능의 저하가 크지 않음을 성능 분석을 통해 보인다.

Annotation-based access control for collaborative information spaces

Web 2.0 social platforms (e.g., Flickr, YouTube) and Collaborative Working Environments (e.g., Microsoft SharePoint, BSCW) provide Web-based collaborative information spaces which enable common users and/or professionals to work together and share their online resources. Most of these collaborative information spaces provide role-based or group-based, coarse-grained access control policies which cannot successfully cope with the requirements posed by massive and open collaboration. In this paper, we present an annotation-based access control (AnBAC) model supported by a Collaboration Vocabulary (CoVoc) as a more flexible and user-centric access control approach. Based on this, we developed two tools: Uncle-Share is a gadget that provides annotation-based access control and can be equipped with CoVoc for annotating collaborative relationships. Who-With-Whom uses CoVoc to visualize extended social networks in order to help users to select appropriate contacts to grant access to resources.

Design and implementation of a user-centric access point selection algorithm based on mutually connected neural networks

We propose an autonomous access point selection algorithm for user-centric radio resource usage optimization in distributed wireless networks. We introduce the optimization algorithm based on the mutually connected neural network, which minimizes a given objective function by distributed update of each neuron. In order to improve the quality of services for each user, we apply such an algorithm to optimization of the balance of the available throughput among the users with keeping higher average throughput per user. The mutually connected neural network to minimize the objective function is realized by calculating the connection weights and the thresholds from the coefficients of the energy function and the target objective function. By computer simulations, we show that the proposed algorithm improves the available throughput for each user in large-scale wireless networks. Furthermore, we implement the proposed algorithm on an experimental wireless network, and verify that each user terminal selects a most appropriate access point to optimize the total radio resource usage based on the state of neurons distributively updated at each user terminal.

User-centric universal multimedia access in home networks

Much research is currently being conducted towards Universal Multimedia Access, aiming at removing barriers that arise when multimedia content is to be consumed with more and more heterogeneous devices and over diverse networks. We argue that users should be put at the center of the research work to enable user-centric multimedia access. In this paper we present the requirements for a user-centric multimedia access system in a networked home environment. These requirements are easy access to available content repositories, context awareness, content adaptation and session migration. After showing the limits of state-of-the-art technologies, we present the architecture of a system which allows unified access to the home network content, automatically delivered to rendering devices close to the user, adapted according to the rendering device constraints, and which is also capable of session mobility.