Soonghwan Ro

Simplified fast handover in mobile IPv6 networks

The Fast Handovers for Mobile IPv6 (FMIPv6) protocol provides seamless handover; it uses anticipation based on layer 2 trigger information of the mobile node (MN) to obtain a new care-of address at the new link while still connected to the previous link, thus reducing handover delay. A bidirectional tunnel is then established between access routers to minimize packet loss during the handover. However, this method incurs higher signaling costs compared with the standard Mobile IPv6 protocol. In many cases, the mobile node cannot complete the fast handover in predictive mode due to lack of time, especially with high-speed movement of the mobile node. This paper proposes an enhancement to the FMIPv6, the Simplified Fast Handover in Mobile IPv6 Networks (SFMIPv6), which significantly reduces the anticipation time of the fast handover and thereby increases the probability that the protocol can perform the fast handover in predictive mode. In this paper, we also present performance evaluations in terms of the influence of two factors, the break-down point and the velocity of the MN, using evaluation models. The numerical results prove that the network performance of the proposed protocol is effectively improved compared to the original protocols, the FMIPv6 and Fast Handover Support in Hierarchical Mobile IPv6 (F-HMIPv6). Moreover, the results show that the proposed protocol could appropriately operate with high-speed mobile node movement.

A modified AOMDV routing protocol for maritime inter-ship communication

In maritime communication, QoS problem caused by routing is very important. In this paper, we propose a method based on AOMDV protocol providing a route recovery mechanism when a link breaks in an active route to reduce lost packets. The results show that the proposed method can reduce packet loss ratio and delay time compared with the AOMDV.

Global mobility support in Proxy Mobile IPv6 for mobility-unaware hosts

The Proxy Mobile IPv6 (PMIPv6) is a network localized mobility management protocol that is independent of global mobility management protocols. In a single mobility domain (LMD), the mobile node (MN) is not involved in any IP mobility-related signaling and uses only its PMIPv6 home address for all its communication. Subsequently, when the MN moves into another LMD, the MN must change its PMIPv6 home address. In such a circumstance, host-based mobility signaling is activated. Thus, the nature of the network-based mobility of the PMIPv6 cannot be retained. Additionally, if the MN does not support global mobility, it cannot maintain communication with its correspondent node (CN). In this paper, we propose a solution for global mobility support in PMIPv6 networks, called G-PMIPv6 that allows current communication sessions of a MN without mobility protocol stacks to be maintained, even when the MN moves into another LMD. Thus, G-PMIPv6 retains the advantages of the PMIPv6 for global mobility support. We then evaluate and compare network performance between our proposed solution and PMIPv6.

Usability Evaluation on XVC Framework for In-Vehicle User Interfaces

XVC (extensible viewer composition) is an in- vehicle user interface framework for telematics applications. It provides a document-oriented applications model enables drivers to make use of multiple information services simultaneously, while maintaining satisfactory control of their vehicles. XVC is a new client model which makes use of beneficial functions of in-vehicle navigation devices. However, there was no usability evaluation on XVC framework before this work. In this paper, we present the usability test on XVC framework that was performed to evaluate how the XVC client may affect the driving work of drivers while trying to make use of its functions. The evaluation was performed using the advanced automotive simulator system at KATECH (Korea Automobile Technology Institute). Furthermore, we also analyzed the advantages of XVC Framework and compared over non-XVC Framework through test results.

Inter-domain mobility support in Proxy Mobile IPv6 using overlap function of mobile access gateway

In a single local mobility domain of Proxy Mobile IPv6 (PMIPv6) the mobile node (MN) uses only its PMIPv6 home address for all its communication. When the MN moves into another domain, the MN must change its PMIPv6 home address and host-based mobility signaling is activated. Consequently PMIPv6’s network-based mobility cannot be retained. Additionally, if the MN does not support inter-domain mobility, it cannot maintain its communication sessions with its correspondent node (CN). In this paper, we propose a inter-domain mobility support protocol in PMIPv6 networks using overlap function of mobile access gateway called overlap-MAG. In overlap-MAG protocol an MN maintain active communication sessions without mobility protocol stacks when the MN moves into another local mobility domain. Thus, overlap-MAG protocol retains the advantages of PMIPv6 for inter-domain mobility support. However only a few modifications are necessary on the mobile access gateway without any modifications of MN and CN’s protocol stacks. Thus, overlap-MAG not only simplifies implementation and deployment, but also allows service providers to offer multi-services and communication ubiquity to customers with simple mobility hosts. We evaluate and compare network performance between our proposed solution and PMIPv6 and the main host-based mobility protocol, MIPv6 to demonstrate the advantages of proposed protocol.

Algorithm for Fire Detection using a Camera Surveillance System

In this paper, we propose a real-time fire detection algorithm for use with a surveillance camera system. Candidate regions of fire flames are recognized by temporal analysis of the flickering energy and color models of image pixels in frames. We also develop a robust fire flame classifier using a cascade model that joins many weak classifiers into one robust and precise classifier capable of distinguishing true fire and non-fire regions. Experimental results show that the proposed algorithm is absolutely suited for real-time fire detection with high precision.

A robust ICI suppression based on an adaptive equalizer for very fast time-varying channels in LTE-R systems

High-speed railway communication implemented based on Long-Term Evolution-Railway (LTE-R) Platform has strict requirements for quality of services to support high data-rate transmission for numerous mobile users. In such environment, there often exists inter-carrier interference. In this paper, we exploit a robust channel estimation method in the time domain for very fast time-varying LTE-railway channels, and then, we propose an effective and adaptive frequency-domain equalizer that can offer a tradeoff between performance and computational complexity. The simulation results show the robustness of our proposed method compared with previous ones. The computational complexity of the proposed method retain at a decent number by exploiting specified properties of channel matrices.

A Design and Implementation of Lightweight ENC for Android App

A large ship has an expensive electronic chart display and information system (ECDIS) installed on its bridge for the safety of navigation and uses a variety of mobile equipment for auxiliary purposes. In contrast, small- and mid-sized vessels, passenger ships and fishing boats employ mobile equipment instead of such ECDISs, as their primary devices for navigation. Small-sized vessels only require some information and features of the ECDIS owing to the performance and resource restrictions of mobile devices and the characteristics of inshore or offshore navigation. This study proposed information lightening and indexing methods for electronic navigational charts to fit mobile equipment and implemented a tailored display configuration feature for navigators.

A novel antenna tracking technique for maritime broadband communication (MariComm) system

Maritime communication is internationally protected because closely related to the maritime safety, and it has evolved slower than terrestrial communication technologies. However, with the recent rapid advances in communication technology, maritime communications have become faster and increasingly modernized. A maritime broadband wireless data communication (MariComm) system was developed to make two-way high-speed internet/multimedia services available at a rate of 1 Mbps or more on the sea by extending the communication coverage of terrestrial wireless communications networks to sea areas. The MariComm system uses high-gain directional antennas to extend the transmission range and has multiple directional antennas to cover 360 degrees in azimuth. In this paper, we introduce a directional antenna tracking technique and apparatus using received RF signal and ship location information in the MariComm system.

A Study on ENC Data Translation for Mobile Device

Recent paradime for convergrnce technology between traditional maritime industry and ICT has spotlighted, especially applied for the prevention of accidents and for remedies. With the introduction of samrt ship and recent addvance in the communication technology, the accidents in coastal areas has not been reduced. The reason is that those accidents were caused by small vessels which have not fully eqipped with navigational and communication system. In this paper, we introduce a electronics chart system for mobile devices based on international standard, S-57, in small vessels. For this system, we propose a data transformation scheme applicable to mobile device. Finally, we illustrate some experiments and results of the system which is implemented with Android platform.