• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.5785-5804
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• 2019

The information of localization is a fundamental requirement in wireless sensor network (WSN). The method of distance vector-hop (DV-Hop), a range-free localization algorithm, can locate the ordinary nodes by utilizing the connectivity and multi-hop transmission. However, the error of the estimated distance between the beacon nodes and ordinary nodes is too large. In order to enhance the positioning precision of DV-Hop, fast triangle flip bat algorithm, which is based on curve strategy and rank transformation (FTBA-TCR) is proposed. The rank is introduced to directly select individuals in the population of each generation, which arranges all individuals according to their merits and a threshold is set to get the better solution. To test the algorithm performance, the CEC2013 test suite is used to check out the algorithm's performance. Meanwhile, there are four other algorithms are compared with the proposed algorithm. The results show that our algorithm is greater than other algorithms. And this algorithm is used to enhance the performance of DV-Hop algorithm. The results show that the proposed algorithm receives the lower average localization error and the best performance by comparing with the other algorithms.

• Journal of Internet Computing and Services
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• v.9 no.1
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• pp.159-170
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• 2008

The ubiquitous network revolution is beginning with the onset of digital convergence, whereby computers, horne appliances, and communications and broadcast media are being unified into digital media with the founding of the information super high speed. This technical advancement is creating a new culture and a new space and accelerating society's transition to the new and unique social paradigm of a 'ubiquitous society'. In particular, studies on ubiquitous communications are well underway. Lately, the focus has been on the Bluetooth technology due to its applicability in various environments. Applying Bluetooth connectivity to new environments such as ubiquitous or sensor networks requires finding new ways of using it. Thus, the scalable Bluetooth piconet scheme with independent slave device is proposed. It follows from work by Sea et al. But extended scatternet is not considered is Kiisc05 paper. Therefore, we propose secure bridge connection scheme for scalable Bluetooth scatternet.

• Journal of Internet Computing and Services
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• v.12 no.2
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• pp.55-62
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• 2011

To make service location protocol of IETF which is to be used in the wide area network to discover the location of desired service when computing resources are connected to the network, and to support simless connectivity between wired and wireless network in service viewpoint, to support the diversity trend of service agents in WIF, it needs to improve SLP, so as to add Liaison Agent and Forwarding Agent with FAAdvert message that is to communicate in between those entities. LA entity confirms the location of service located in wide area network, and FA transfers service information. The usage of existing messages such as SrvRqst, SrvRply, AttrRqst, AttrRply, DAAdvert, SrvReg, SrvAck, SrvDeReg is same as ever in wide area service network. The behaviors of improved protocol is modeled into petri-net and prove that it is free of deadlock and live-lock by execution of the model.

• Journal of Internet Computing and Services
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• v.15 no.4
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• pp.111-118
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• 2014

In mobile sensor networks, a large number of sensor nodes with battery powered are deployed randomly in a region. They monitor the environmental states and transmit data to its neighboring nodes. For mobile sensor networks, It is needed to maintain the connectivity autonomously among nodes as the sensor node moves. However, the existing works have focused on the energy savings in the fixed sensor networks. A specific algorithm considering node mobility is required in the mobile sensor networks. Along with energy efficiency, the transmission delay should be considered. In this paper, we propose an autonomous configuration scheme and a node scheduling algorithm when a moving node joins into the existing network. Through simulations, we show a superior performance of the proposed algorithm to the existing protocol.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.51-57
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• 2015

In this paper, we tried to broaden a width of practical use field for applications through combining to existing contents after constructing various contents for companion animals. For this, we designed and developed our new companion animal management system(PET-IN) by adding various contents such as information management, schedule management, health management, QR code, SNS, shopping, map service for companion animals to smartphone applications. By PET-IN accessibility and satisfactory level tests, we found out that new synergy effect have appeared through combining each contents, and connectivity is increased. So, practical use field is broaden. These tests show us that comprehensive content composition is necessary for companion animal applications, and this study can be used as important data when new companion animal application contents are constructed in the future.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.9
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• pp.707-714
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• 2013

IoT, which can be regarded as an enhanced version of M2M communication technology, was proposed to realize intelligent thing to thing communications by utilizing Internet connectivity. Things in IoT are generally heterogeneous and resource constrained. Also such things are connected with each other over LLN(low power and lossy Network). Confidentiality, mutual authentication and message origin authentication are required to make a secure service in IoT. Security protocols used in traditional IP Networks cannot be directly adopted to resource constrained devices in IoT. Under the respect, a IETF standard group proposes to use lightweight version of DTLS protocol for supporting security services in IoT environments. However, the protocol can not cover up all of very constrained devices. To solve the problem, we propose a scheme which tends to support mutual authentication and session key agreement between devices that contain only a single crypto primitive module such as hash function or cipher function because of resource constrained property. The proposed scheme enhances performance by pre-computing a session key and is able to defend various attacks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2724-2730
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• 2015

Internet of Things (IoT) is possibly the most widely discussed technological concept in today's technology circles. This technology is expected to dramatically change not only how we work but also how we live. The concept of IoT basically means a web of connected devices which can be controlled over a data network. With cost of technology required to control these devices going down and increasing internet connectivity through smartphones, IoT is expected to be an all pervasive technology in the next 10 years. In this paper, we study the technological landscape of this fast growing technology domain from an Intellectual Property (Patents) perspective. We find that the patent distribution in this domain is very fragmented with the top patent applicants in the field holding around 5% of the total patents. Especially, the US geography has seen the maximum patent filings and is closely followed by the big Asian markets of Japan and Korea.

• Journal of Internet Computing and Services
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• v.5 no.2
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• pp.75-84
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• 2004

Geocasting, a variant of the conventional multicasting problem, is one of communication type in which the data packets are delivered to a group of all nodes within a specified geographical region (i.e., the geocasting region) and is called location-based multicasting(LBM)(l). An Ad-hoc network is a dynamically reconfigurable and temporary wireless network where all mobile devices using batteries as energy resources cooperatively maintain network connectivity without central administration or the assistance of base stations. Consequently, the technique to efficiently consume the limited amounts of energy resources is an important problem so that the system lifetime is maximized. In this paper, we propose a LBPA(Location-Based Power Aware) geocasting algorithm that selects energy-aware neighbor to route a packet towards the target region In Ad-hoc network environments. The method Is such that the energy consumption is balanced among the nodes in proportion to their energy reserves. Through the simulations, the proposed LBPA algorithm shows better results, that is, as good as 40% on the average over the conventional LBM algorithm in terms of the network lifetime.

• Journal of Internet Computing and Services
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• v.4 no.4
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• pp.15-25
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• 2003

Wireless ad-hoc networks are only composed with mobile devices. Unlike the traditional wired networks, those devices are mostly operated with battery power. Since the battery-operated power is limited, the efficient energy resource managements becomes an important issue in wireless ad-hoc networks and various studies that considered these characteristics are progressed. One of those studies is an energy efficient routing using coordinators. In this method. only devices elected as coordinator participate in data transmissions in ad-hoc networks, while other devices remain in sleep node. The overall energy consumption of a system can be reduced. In order to minimize energy consumption of a total network, previous results try to maximize the number of nodes in sleep mode. However, minimizing the number of coordinators does not ensure to increase the system lifetime. In this thesis, we propose an algorithm that can elect coordinators with considering the amount of necessary energy to transmit assigned data and a connectivity of nodes in the networks. The result of proposed coordinator election algorithm can increase the system lifetime of an Ad-hoc network from the results of existing coordinator election algorithms.

• Journal of Information Processing Systems
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• v.5 no.3
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• pp.117-130
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• 2009

By providing ubiquitous Internet connectivity, wireless networks offer more convenient ways for users to surf the Internet. However, wireless networks encounter more technological challenges than wired networks, such as bandwidth, security problems, and handoff latency. Thus, this paper proposes new technologies to solve these problems. First, a Security Access Gateway (SAG) is proposed to solve the security issue. Originally, mobile terminals were unable to process high security calculations because of their low calculating power. SAG not only offers high calculating power to encrypt the encryption demand of SAG's domain, but also helps mobile terminals to establish a multiple safety tunnel to maintain a secure domain. Second, Robust Header Compression (RoHC) technology is adopted to increase the utilization of bandwidth. Instead of Access Point (AP), Access Gateway (AG) is used to deal with the packet header compression and de-compression from the wireless end. AG's high calculating power is able to reduce the load on AP. In the original architecture, AP has to deal with a large number of demands by header compression/de-compression from mobile terminals. Eventually, wireless networks must offer users "Mobility" and "Roaming". For wireless networks to achieve "Mobility" and "Roaming," we can use Mobile IPv6 (MIPv6) technology. Nevertheless, such technology might cause latency. Furthermore, how the security tunnel and header compression established before the handoff can be used by mobile terminals handoff will be another great challenge. Thus, this paper proposes to solve the problem by using Early Binding Updates (EBU) and Security Access Gateway (SAG) to offer a complete mechanism with low latency, low handoff mechanism calculation, and high security.