The advanced cellular network, long term evolution (LTE) that presently operates in licensed spectrum has been extended to unlicensed LTE (U-LTE) to improve data rate and spectral efficiency by utilizing unlicensed spectrum. Carrier aggregation of 3GPPLTE-A supports the aggregation of licensed and unlicensed spectrum in small and femto cells to provide better user experience. The proposed work consists of two objectives, first to accomplish the listen-before-talk (LBT) regulatory requirement of radio communication in U-LTE and the second to enhance their co-existence with Wi-Fi/IoT users in a non-interference style by reducing the back-off rate of Wi-Fi. The importance of spectrum utilization by the incumbent users of unlicensed band for the upcoming Internet of Things communications is also a key consideration in this work. The recently evolved intelligent technology viz. Cognitive radio (CR) is applied in the proposed system model to meet the objectives. A ground research is done in a simulation environment of LTE signals and 5 GHz band to evaluate the back-off rate of Wi-Fi. A comparative performance analysis between proposed and existing systems are also done and presented in this paper. © 2017, Springer Science+Business Media, LLC, part of Springer Nature.

Arun Kumar S

Department of Information Security

School of Computer Science and Engineering

Vellore Campus

Sumathi A.C

Vidhyapriya R

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Cluster Computing

Enhancing 4G Co-existence with Wi-Fi/IoT using cognitive radio

Lecture Notes in Electrical Engineering Frontier Computing

Study of CR Based U-LTE Co-existence Under Varying Wi-Fi Standards

Energy-efficient and robust-time synchronization is crucial for industrial Internet of things (IIoT). Some energy-efficient time synchronization schemes that achieve high accuracy have been proposed recently. However, some unsynchronized nodes namely isolated nodes exist in the schemes. To deal with the problem, this paper presents R-Sync, a robust time synchronization scheme for IIoT. We use a pulling timer to pull isolated nodes into synchronized networks whose initial value is set according to level of spanning tree. Then, another timer is set up to select backbone node and its initial value is related to the distance to parent node. Moreover, we do experiments based on simulation tool NS-2 and testbed based on wireless hardware nodes. The experimental results show that our approach makes all the nodes get synchronized and gets the better performance in terms of accuracy and energy consumption, compared with three existing time synchronization algorithms TPSN, GPA, STETS. © 2005-2012 IEEE.

IEEE Transactions on Industrial Informatics

A Robust Time Synchronization Scheme for Industrial Internet of Things

Many applications, such as intelligent transportation systems and mobile multimedia, use Internet of Vehicles (IoV). In IoV, users often access multimedia content from anywhere using Internet connectivity to remote video streaming servers. Due to the high mobility of the nodes in IoV, however, maintaining quality of service (QoS) for these video streaming applications with respect to parameters such as jitter, throughput, buffering, and transmission delays is a challenging task. Especially in the urban environment, the performance of a video streaming protocol is significantly affected by the variation of the traffic density. As a result, how to effectively analyze the impact of traffic density as well as vehicular mobility on the QoS of video streaming is the key for the routing protocol design in IoV. In this paper, based on the relationship between the traffic density and the latency characteristics in urban environment, two models are proposed to accurately estimate the video streaming latency according to the average inter-vehicle distance and radio range. After that, an optimal routing strategy is given by selecting the path from all available paths to minimize the experienced latency for video streaming. Numerical results show that in urban environments, our proposed model has high accuracy under different configurations. © 2017 Elsevier B.V.

Computer Communications

Latency estimation based on traffic density for video streaming in the internet of vehicles

Sakarya University Journal of Science

Wi-Fi and LTE-LAA coexistence problems, challenges and features in 5GHz unlicensed bandwidth

IEEE Transactions on Sustainable Computing

ESCAPE: Effective Scalable Clustering Approach for Parallel Execution of Continuous Position-Based Queries in Position Monitoring Applications

Journal	Data powered by TypesetCluster Computing
Publisher	Data powered by TypesetSpringer Science and Business Media LLC
ISSN	1386-7857
Open Access	0