Recent Advances in Communications and Networking Technology (Formerly Recent Patents on Telecommunication) (Discontinued) - Volume 4, Issue 1, 2015

Different methods of standard definition (SD) to high definition (HD) image conversion are compared according to the PSNR criterion. Subjective comparison is difficult as there is almost no quality difference between them. For comparison, an original HD and the correspondent SD images are required. The SD image is up-converted to approximate HD images using various methods and then these approximated images are compared to the original HD image. In such a comparison the main question is how to generate the SD image. Both analytical and simulation results show that the method of generation of the SD image has a great influence on the outcome of PSNR results. Immediate down-sampling, Filtered down-sampling, Discrete Fourier Transform (DFT)-based down-sampling and Discrete Cosine Transform (DCT)-based down-sampling are methods we used to generate SD image from the original HD image. Ideal low pass signal (Nyquist) interpolation, DFTbased up-sampling and DCT-based up-sampling are the three methods we used to up-convert SD to HD image. As it is seen, the highest PSNR (least error) is the mean squared value of the omitted high frequency components during down-sampling process in transform-based methods. The analytical formulation of PSNR in filtered-based methods is not simple due to distortions in the frequency response of filters and aliasing in frequency domain.

Video surveillance has a growing importance in public safety services. Departments and organizations delivering public safety and security services often need to resort to covertness in their activities. They usually compromise on distance, lens size and light to insure secrecy; these compromises present challenges on the quality and usefulness of the captured video. Moreover, outdoor surveillance systems, especially over long distances, are often constrained to wireless networks to transport the video back to the monitoring offices. The design of such application is multi-faceted and covers both video processing and the delivery network. In this paper, we study the challenges of video surveillance, covering most of the phases of a typical surveillance system, and present a roadmap to render the surveillance video, collected over long distances, useful in the pursuit of investigations and responsive to the requirements of different target recognition levels.

High Density WSN deployments applicable to large scale area extent is a venture of vital importance for a number of critical infrastructures. National borders monitoring, prediction and prevention of natural disasters and even crisis management issues comprise the wide application filed. Because of the critical role of the application and for expense reasons as well, the efficiency of the network should be assured. Emphasis has been given to connectivity and redundancy concerns, as they constitute the main contributory factor to a fully operational network. Therefore, topology, with respect to simulation issues, includes all the aforementioned terms. In this paper, we analyze the extended grid of cells topology with overlaps and its enhancement, with the aim to reduce cost and increase the response time of a monitoring network, which mainly acts as an early warning system. The proposed topology meets the specific problem requirements of large scale area coverage with high density sensor networks and provides a feasible and an efficient solution to it. This topology is applied in an expandable way, taking into consideration simulation results. The proposed network architecture combines the node signal attenuation with its localization for redundancy sake. The topology resembles the cellular phone network architecture, yet it is deployed according to WSN characteristics and limitations. It constitutes the fundamental – theoretical topology approach upon which elevation and trees location will be taken into consideration in the forthcoming research. As a result, an appropriate WSN topology with increased efficiency and reduced cost per particular area is proposed. What is more, estimations and quantitative analysis regarding network devices and installation procedure are performed.

The proposed paper, presents a new architecture on cloud platform which shifts complete office to cloud. It includes building an application as office but emphasized more on authentication function. It demonstrates the virtual organization on the cloud which provides the virtual workspace environment to the registered user. The web based application includes interactive services to users through the use of WebRTC and different web technologies. Through the use of web services the security part is challenged. The basic aim of the work is to build a strong security measure, authentication functions, to users for accessing the “Office in the cloud”. Evaluation of services in terms of feasibility and quality is highlighted. The proposed algorithm is checked with the existing algorithm which provides the security for applications on the cloud. Two Way Encryption (TWE) authenticates the user to access the data stored on the cloud. Hence the authentication is categorized in two ways as, user authentication and the application authentication, where the organization is deployed on the private cloud.

With the increase in mobile devices there is also an increase in demand for IP mobility across networks. Although not created for that purpose, the LISP protocol offers a clean solution for mobility, via an end-to-end map/encap scheme. The solution offered by LISP allows a mobile device to keep its IP address even when changing networks. LISP’s mobility method, however, breaks when the mobile device does not have access to a publicly routable IP address, which is to be expected in today’s NAT dominated world. The LISP proposed NAT traversal solution suffers from suboptimal routing and unnecessary provider dependance. This has two major effects: increased latency, which is especially worrisome on short lived connections, and worse performance due to extended reconfiguration time during mobility events. In this paper we propose an alternative NAT traversal mechanism for LISP, by adding LISP functionality to the NAT device. The evaluations performed, by simulation and over a proof of concept prototype, show that both hindrances may be suppressed. Additionally, our experience shows that, at least for a mobile device, the LISP control plane is uselessly overburdening.