International Journal of Space-Based and Situated Computing (6 papers in press)
On the Target Channel Sequence Selection for Multiple Handoffs in Cognitive Radio based Wireless Regional Area Networks
by Isaac Woungang
Abstract: In cognitive radio networks, handoff occurs when an unlicensed spectrum user has to switch to a new target channel from its current operating channel which a secondary user was using opportunistically. This situation arises whenever either the licensed primary user appears again or the channels condition get worst. Substantial sensing time can be saved if a secondary user can make a proactive decision about selecting the future vacant target channel to resume the unfinished transmission before starting its transmission. This paper proposes a novel target channel sequence selection scheme for cognitive radio networks, which minimizes the estimated service time of a secondary user by reducing the multiple handoffs. A non-iterative algorithm is implemented, which does not require the use of an exhaustive search technique as usual to determine the target channel sequence. Simulation results show that the proposed scheme outperforms both the random scheme and a considered benchmark scheme in terms of service time, cumulative handoff delay and throughput achieved by the secondary user.
Keywords: IEEE 802.22 WRAN; cognitive radio; multiple handoffs; total service time; handoff delay; discrete Markov chain; artificial neural network.
Location-based applications, services and technologies in aid of flight planning and GPS based navigation for visual flight rules (VFR) in developing countries: with a case study
by Ermir Rogova, Arianit Maraj, Blerat Ukaj
Abstract: General aviation (GA) flights range from gliders and powered parachutes to corporate business jet flights. The majority of the world's air traffic falls into this category, and most of the world's airports serve general aviation exclusively. General aviation covers a large range of activities, both commercial and non-commercial, including flying clubs, flight training, agricultural aviation, light aircraft manufacturing and maintenance. As such general aviation plays an important role in the economic development of a country. Visual flight rules (VFR) are a set of regulations under which a pilot operates an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. This paper will treat the importance of VFR flight planning. It will cover the navigational database, navigation points, restricted zones, obstacles, positioning, air speed and routes based on GPS (Global Positioning System). It will provide an overview of the spatial data base for planning of flights and registration of navigational coordinates for positions. Additionally, it will also analyze aspects of the flight safety by navigating on GPS. The paper then continues with an analysis of a planning process of VFR flights in Kosovo and the impact of an electronic system for flight planning and navigation increased safety during the VFR flights in Kosovo airspace. The practical implementation of this paper will result in the development of a bespoke software application for planning electronic flights, flight plan, points standard navigational, navigation based on GPS from point to point by calculating the time, distance, position, height, and the way to be followed.
Keywords: Visual flight rules; navigation; GPS; general aviation; location-based applications.
Special Issue on: Advanced Technologies for Next-Generation Communications and Networked Applications
Introduction to content centric network architectures replacing traditional location centric network
by Tetsuya Shigeyasu
Abstract: Nowadays, Internet has became most important infrastructure used by the population over the 38.8 billion.rnThe Internet is the inseparable from our daily life. The Internet based on such location centric communication, however, may induces high risk of networkrncongestion and network service down due to network traffic dominated by contents delivery and multimedia applications. rnThen, the concept of CCN (Content Centric Network) or ICN (Information Centric Network) has been attracting the attention to resolve the problems under the location based network architecture.rnThis paper explains the overview of the overview of network architectures based on CCN concept in order to help researchers developing well suited next-generation CCN based network architectures.
Keywords: content centric network; host centric network; in-network caching; caching algorithm.
Design and Evaluation of a Utility Tool for Recorded Class B AIS Data in an Unstable Maritime Environment
by Misako Urakami, Hisaya Motogi, Tomohiro Sunada, Kenshiro Okamura, Takayuki Watanabe, Nobukazu Wakabayashi
Abstract: We focus on the automatic identification system (AIS), which is a probe data system. Some researchers propose using this system not only to support ship handling, such as through collision avoidance, but also in other ways, such as for navigation time analysis, accident tracing, or navigation management by administrators on land. Therefore, we focus on the importance of obtaining more marine ship position information, including that for a small ship using Class B AIS, to enrich the intelligent transport system service for marine traffic. First, we develop a processing tool to create an operation management book from the recorded AIS data. We then study the implementation of these utility tools and evaluate their effectiveness.
Keywords: Information processing tool; Utility tool; Intelligent transport system; ITS for the sea; Probe data; Automatic identification system; Class A AIS; Class B AIS; Maritime environment; Navigation management; GPS;.
Ray-Tracing Analysis of the Radio Propagation on the Line-Of-Sight Maritime Wireless Environments
by Masaaki Yamanaka, Daiki Hashimoto, Yasuhiro Sato, Kohei Shimada, Yoshinori Matsuura
Abstract: Due to heavy maritime traffic, wireless systems play an important role to maintain the traffic safety. In this paper, we try to analyze the radio propagation of wireless systems in maritime environments. As the maritime radio wave propagation has not been amply analyzed yet, the method and the result presented in the paper will be a good guide to implement a system fit in the assumed location. Although, there are many wireless systems should be covered, we picked up a radar system in this paper. As the system uses direct wave to detect floating objects on sea surface, the main objective of this paper is to analyze the Line-Of-Sight maritime radio wave propagation. In general, radar antennas are set in the highest location from sea level in order to get a line-of-sight view for a wide area. However, there are cases when high islands or hills hamper the line-of-sight. In this case, the system is not able to see the area through the radio waves, which will cause a serious problems for navigation safety. We will try to assess the area using a ray-tracing method applied in the environment. The procedure of using the Geospatial Information Authority of Japan (GSI)'s topographical data is given, to assess the exact area where the radio waves are unable to reach, through simulation.
Keywords: Maritime traffic safety; Radio wave propagation analysis; Radar system; Ray-tracing method.
Multi-overlay information management for IoT-oriented P2P network applications
by Kazunori Ueda, Makoto Iwata, Ken-ichi Baba
Abstract: In the IoT environment, network applications such as various content/resource sharing, remote sensing, and so on play an important role to realize flexible and efficient communication on the network. If requested content/resource is retrieved from a huge number of various IoT devices, the amount of content/resource management information increases tremendously and most of IoT devices might not have enough computing/networking resource to maintain such management information. Thus, it is indispensable to introduce scalable management scheme and powerful delegate server for the IoT environment. This paper proposes a peer-to-peer information management scheme using multi-overlay network. The peer-to-peer networking is one of the promising ways to achieve scalability of the network applications and the multi-overlay network plays a role to provide a logical network structure adaptive to requested content/resource distribution. The evaluation results of a prototype with content-based and distance-based overlay networks revealed that we can implement IoT-oriented network applications while keeping practical search efficiency as well as saving network resource.
Keywords: IoT; P2P; Overlay network; Multi-overlay; Clustering.