scispace - formally typeset
Search or ask a question
Author

Chatterjee Shubhajeet

Bio: Chatterjee Shubhajeet is an academic researcher. The author has contributed to research in topics: Handover & Mobile station. The author has an hindex of 3, co-authored 4 publications receiving 16 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: An algorithm is designed to first scan the channels 1, 6 and 11, if present under the next Access Point (AP), to reduce the scanning delay, and introduces pre-authentication mechanism, which will effectively reduce the message processing delay.
Abstract: Presently, IEEE 802.11 based wireless local area networks (WLAN) have been widely deployed for business and personal applications. The main issue regarding wireless network technology is handoff or hand over management. When a mobile station (MS) moves outside the range of its current access point (AP) it needs to perform a link layer handover. This causes data loss and interruption in communication. According to IEEE 802.11, link layer2 (L2) handoff is performed in three phases – scanning, authentication and re-association. Scanning process causes 90% of the total handoff delay. Throughout the last few years, plenty of researches had been done to reduce the hand off delay by reducing the scanning delay. In this paper, we propose to reduce handoff latency for IEEE 802.11 wireless networks with Neighbor Graphs (NG) pre-scanning mechanisms. IEEE 802.11 uses 11 channels of which the channels 1, 6 and 11 do not mutually overlap. So these channels are expected to have a lower carrier-to-interference ratio (CI) compared to other channels under the same base station, which increases the channel‟s availability during handoff. Based on the NG prescanning mechanism, when handoff criterions have been met, we design an algorithm to first scan the channels 1, 6 and 11, if present under the next Access Point (AP), to reduce the scanning delay. We also introduce pre-authentication mechanism, which will effectively reduce the message processing delay.

5 citations

Journal ArticleDOI
TL;DR: An algorithm to first determine the Access Point under whose coverage area the Mobile Station (MS) would enter, then scanning the channels 1, 6 and 11, if present under the next Access Point (AP), to reduce the scanning delay is designed and pre-authentication mechanism is introduced, which will effectively reduce the message processing delay.
Abstract: IEEE 802.11b networks are becoming more ubiquitous. While roaming through access points, a Mobile Station is often required to perform a link layer handover. This mechanism causes connection losses and breaks in time-sensitive communication, especially if a network layer handover follows the link layer handover. In this paper, we propose to reduce handoff latency for IEEE 802.11 wireless networks with Neighbor Graphs (NG) pre-scanning mechanisms and using a GPS based server which predetermines the next probable AP using three formulated geometry based mathematical techniques. IEEE 802.11 uses 11 channels of which the channels 1, 6 and 11 do not mutually overlap. As they are non-overlapping, the channels are expected to have a lower carrier-to-interference ratio (CI) compared to the other channels present under the same base station, which increases the channel‟s availability during handoff. When handoff criterion have been met, we design an algorithm to first determine the Access Point (AP) under whose coverage area the Mobile Station (MS) would enter, then scanning the channels 1, 6 and 11, if present under the next Access Point (AP), to reduce the scanning delay. We also introduce pre-authentication mechanism, which will effectively reduce the message processing delay.

4 citations

Journal Article
TL;DR: Two handover initiation algorithms with connection control are introduced and the angle and the distance between the MS and satellite after a defined sample interval serves as a data set for decision making in these two algorithms.
Abstract: In satellite communication networks, low propagation delay and power requirements increase the plausibility of Low Earth Orbit (LEO) satellites over geostationary Earth Orbit (GEO) satellites. High relative speed and random direction of motion of LEO satellites provide a serious barrier for their applicability in global wireless communication. The spot beam dynamics of LEO satellites brings about frequent handover of connections between spot-beams for the Mobile Stations (MS). This paper introduces two handover initiation algorithms with connection control. The angle and the distance between the MS and satellite after a defined sample interval serves as a data set for decision making in these two algorithms. A threshold limit is set in each algorithm (threshold angle and threshold distance) which when crossed results in handoff initiation. The simulations were performed in MATLAB 7.8 where a virtual coded scenario with aid of available data was created and the algorithm was executed in it.

4 citations

Journal ArticleDOI
TL;DR: This paper introduces a prescanning mechanism in which an STA starts scanning before it needs actual handoff, and simulation results show that the proposed method reduces the handoff latency effectively.
Abstract: Due to rapid growth in IEEE 802.11 based Wireless Local Area Networks (WLAN), handoff has become a burning issue. A mobile station (MS) requires handoff when it travels out of the coverage area of its current access point (AP) and tries to associate with another AP. But handoff delays provide a serious barrier for such services to be made available to mobile platforms. Throughout the last few years there has been plenty of research aimed towards reducing the handoff delay incurred in the various levels of wireless communication. In this paper, based on Neighbor Graph Cache (NGC), we introduce a prescanning mechanism in which an STA starts scanning before it needs actual handoff. The simulation results show that the proposed method reduces the handoff latency effectively.

3 citations


Cited by
More filters
Journal ArticleDOI

164 citations

Journal ArticleDOI
TL;DR: A vision and framework for the HAPS networks of the future supported by a comprehensive and state-of-the-art literature review is provided and the unrealized potential of HAPS systems is highlighted and elaborate on their unique ability to serve metropolitan areas.
Abstract: A High Altitude Platform Station (HAPS) is a network node that operates in the stratosphere at an of altitude around 20 km and is instrumental for providing communication services. Precipitated by technological innovations in the areas of autonomous avionics, array antennas, solar panel efficiency levels, and battery energy densities, and fueled by flourishing industry ecosystems, the HAPS has emerged as an indispensable component of next-generations of wireless networks. In this article, we provide a vision and framework for the HAPS networks of the future supported by a comprehensive and state-of-the-art literature review. We highlight the unrealized potential of HAPS systems and elaborate on their unique ability to serve metropolitan areas. The latest advancements and promising technologies in the HAPS energy and payload systems are discussed. The integration of the emerging Reconfigurable Smart Surface (RSS) technology in the communications payload of HAPS systems for providing a cost-effective deployment is proposed. A detailed overview of the radio resource management in HAPS systems is presented along with synergistic physical layer techniques, including Faster-Than-Nyquist (FTN) signaling. Numerous aspects of handoff management in HAPS systems are described. The notable contributions of Artificial Intelligence (AI) in HAPS, including machine learning in the design, topology management, handoff, and resource allocation aspects are emphasized. The extensive overview of the literature we provide is crucial for substantiating our vision that depicts the expected deployment opportunities and challenges in the next 10 years (next-generation networks), as well as in the subsequent 10 years (next-next-generation networks).

128 citations

Posted Content
TL;DR: In this paper, the authors provide a vision and framework for the HAPS networks of the future supported by a comprehensive and state-of-the-art literature survey, highlighting the undiscovered potential of HAPS systems, and elaborate on their unique ability to serve metropolitan areas.
Abstract: A High Altitude Platform Station (HAPS) is a network node that operates in the stratosphere at an altitude around 20 km and is instrumental for providing communication services. Triggered by the technological innovations in the areas of autonomous avionics, array antennas, solar panel efficiency levels and the battery energy density, and fueled by the flourishing industry ecosystems, the HAPS exerts itself as an indispensable component of the next generations of wireless networks. In this article, we provide a vision and framework for the HAPS networks of the future supported by a comprehensive and state-of-the-art literature survey. We highlight the undiscovered potential of HAPS systems, and elaborate on their unique ability to serve metropolitan areas. The latest advancements and promising technologies in the HAPS energy and payload systems are discussed. The integration of the emerging Reconfigurable Smart Surface (RSS) technology in the communications payload of HAPS systems for providing a costeffective deployment is proposed. A detailed overview of the radio resource management in HAPS systems is presented along with synergistic physical layer techniques, including Faster-Than-Nyquist (FTN) signaling. Numerous aspects of handoff management in HAPS systems are delineated. The notable contribution of Artificial Intelligence (AI) in HAPS, including machine learning in the design, topology management, handoff, and resource allocation aspects are emphasized. The provided extensive overview of the literature is crucial for substantiating our vision that that depicts the expected deployment opportunities and challenges in the next 10 years (next-generation networks), as well as in the subsequent 10 years (next-next-generation networks).

104 citations

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a Billboard Manager based handover (BMBHO) technique using the concept of Billboard Manager (BM) proposed by Aysegul et al in 2006 but in a different way.
Abstract: Now-a-days LEO satellites have an important role in global communication system. They have some advantages over GEO & MEO satellites such as power requirement and endto-end delay is lower and it has more efficient frequency spectrum utilization between satellites and spotbeams. So in future they can be used as a replacement of modern terrestrial wireless networks. But they main problem of LEO satellites is that they have large relative speed than the speed of mobile nodes (MN) & earth. That’s why the handover occurrence is more. So the call blocking probability (Pb) and force call termination probability (Pf) is also higher. To overcome this problem several handover techniques is proposed. Here we propose Billboard Manager based handover (BMBHO) technique using the concept of Billboard Manager (BM) proposed by Aysegul et al in 2006 but in a different way. Here we reduce the scanning time significantly. Also the cost is reduced. Here we also describe how to reduce (Pf). In this paper you will find a set of simulations both for our proposed method & standard handover methods. We can find that this method is very useful by the simulation results.

19 citations