Beijing University of Posts and Telecommunications

About: Beijing University of Posts and Telecommunications is a education organization based out in Beijing, Beijing, China. It is known for research contribution in the topics: MIMO & Quality of service. The organization has 39576 authors who have published 41525 publications receiving 403759 citations. The organization is also known as: BUPT.

Joint Radio Communication, Caching, and Computing Design for Mobile Virtual Reality Delivery in Fog Radio Access Networks

Abstract: The emerging virtual reality (VR) experience demands ultra-high-transmission-rate and ultra-low-latency deliveries, which is challenging for the current cellular networks. Since fog radio access networks (F-RANs) take full advantages of both edge fog computing and caching technologies and benefit different quality-of-service requirements, it is anticipated that high-quality VR experience could be well addressed in F-RANs. This paper presents an F-RAN-based mobile VR delivery framework, in which the core idea is to cache parts of the VR videos in advance and run a certain processing procedure at the edge of F-RANs. To optimize resource allocation at both mobile VR devices and fog access points (F-APs), a joint radio communication, caching and computing decision problem is formulated to maximize the average tolerant delay with meeting a given transmission rate constraint. This problem is formulated as a multiple choice multiple dimensional knapsack problem and solved with the Lagrangian dual decomposition approach. Furthermore, the optimal joint caching and computing decision is analyzed in a specific case with a closed-form expression of the average tolerant delay. The communications-caching-computing tradeoff at both mobile VR devices and F-APs is revealed, and the numerical results demonstrate that local caching and computing capabilities have significant impacts on the average tolerant delay. The proposed mobile VR delivery framework is promising in improving spectral efficiency by maximizing average tolerant delay while meeting high transmission rate requirements.

Secure Data Access Control With Ciphertext Update and Computation Outsourcing in Fog Computing for Internet of Things

Abstract: Fog computing is a paradigm that extends cloud computing to the edge of the network. It can provide computation and storage services to end devices in Internet of Things (IoT). Attribute-based cryptography is a well-known technology to guarantee data confidentiality and fine-grained data access control. However, its computational cost in encryption and decryption phase is linear with the complexity of policy. In this paper, we propose a secure and fine-grained data access control scheme with ciphertext update and computation outsourcing in fog computing for IoT. The sensitive data of data owner are first encrypted using attribute-based encryption with multiple policies and then outsourced to cloud storage. Hence, the user whose attributes satisfy the access policy can decrypt the ciphertext. Based on the attribute-based signature technique, authorized user whose attributes integrated in the signature satisfy the update policy can renew the ciphertext. Specifically, most of the encryption, decryption, and signing computations are outsourced from end devices to fog nodes, and thus, the computations for data owners to encrypt, end users to decrypt, re-encrypt, and sign are irrelevant to the number of attributes in the policies. The security analysis shows that the proposed scheme is secure against known attacks, and the experimental results show that the fog nodes perform most of the computation operations of encryption, decryption, and signing, and hence, the time of encryption for data owner, decryption, re-encryption, and signing for users is small and constant.

Congestion Control Design for Multipath Transport Protocols: A Survey

Abstract: High-quality services over wired and wireless networks require high bitrate network content delivery. Multipath transport protocols utilize multiple paths to support increased throughput for network applications. Ubiquitous mobile devices with multiple interfaces such as WiFi and 4G/5G cellular, and data centers supporting big data analysis and cloud-computing, motivate adoption of multipath transmission in current and future network architectures. Congestion control mechanisms play a fundamental role in these multipath transport protocols. Diverse approaches have been proposed in the literature, differing in terms of their goals, principles, performance, and mostly in how various issues are addressed in their design. This paper presents a survey of congestion control solutions for multipath transport protocols and discusses the multipath congestion control design in order to address the need for some desirable properties including TCP-friendliness, load balancing, stability, and Pareto optimality. Existing window-based and rate-based multipath congestion control algorithms are investigated and categorized based on their theoretical algorithm design. Next, this paper discusses the congestion control mechanisms used in diverse multipath transport protocols in the context of different network scenarios. Finally, the trends in the future multipath congestion control design are presented.

A Review of Face Recognition Technology

Abstract: Face recognition technology is a biometric technology, which is based on the identification of facial features of a person. People collect the face images, and the recognition equipment automatically processes the images. The paper introduces the related researches of face recognition from different perspectives. The paper describes the development stages and the related technologies of face recognition. We introduce the research of face recognition for real conditions, and we introduce the general evaluation standards and the general databases of face recognition. We give a forward-looking view of face recognition. Face recognition has become the future development direction and has many potential application prospects.

Some problems of directional sensor networks

Abstract: Wireless sensor networks are often based on omni-sensing and communication models. In contrast, in this paper, we investigate sensor networks with directional sensing and communication capability. Due to the distinct characteristics and potential effects on coverage and connectivity of the network, novel analysis and solutions are demanded. Towards this end, this paper analyses deployment strategies for satisfying given coverage probability requirements with directional sensing models. Moreover, for sensors with directional communication model, we propose methods for checking and repairing the connectivity of the network. We design efficient protocols to implement our idea. A set of experiments are also performed to prove the effectiveness of our solution.