• Journal of the Korea Society of Computer and Information
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• v.16 no.9
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• pp.45-55
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• 2011

Context awareness technologies are based on efficient sharing of environment information of ubiquitous sensors in everyday life, and users require this awareness technologies to get quality of services. However, the application has been restricted due to its varieties of sensors and many different methods of communications. Therefore, IEEE 1451 standard has been published to interface between sensors and network layer. But it does not connect to a middleware because IEEE 1451 is for transducer standards. This paper presents a transducer and application interface protocol which connect to the context-aware middleware by defining a protocol to obtain context information using XML. We have implemented a bridge health monitoring system and railroad monitoring system in which different sensors and users' application are used to prove the efficacy of proposed interface protocols.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.2
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• pp.124-133
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• 2009

CANopen which is one of the in-vehicle network (IVN) protocols is adopted to solve the hardware dependency problem of the CAN-based application. CANopen makes different CAN devices interoperable each others. By the advantage of the device profiling concept, it can make the period of developing CAN-based application system shorten. The utilization of CANopen network must be reduced to improve the communication performance (e.g. worst-case response time). For reducing network utilization, messages need to be packed as many as possible so that message frame overhead can be decreased. In this paper, we suggested a PDO packing mechanism using object dictionary (OD) and process data object (PDO) communication service in CANopen. Through experiments, the performance of the mechanism is evaluated with SAE benchmark. As a result, network utilization is decreased about 10% compared to the result of the previous works.

• Journal of Internet Computing and Services
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• v.5 no.5
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• pp.39-48
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• 2004

For transporting real-time multimedia traffic, RTP is considered as one of the most promising protocols operating at application layer. In order to manage and control the real-time multimedia traffic within networks, network managers need to monitor and analyze the traffic delivering through their networks. However, conventional traffic analyzing tools can not exactly classify and analyze the real-time multimedia traffic using RTP on the basis of real-time as well as non-real-time operations. In this paper, we propose an efficient online classification method of RTP packets, which can be used on high-speed network links. The accuracy and efficiency of the proposed methodhave been tested using captured data from a KIX node with 100 Mbps links, which interconnects between domestic and overseas Internet networks and is operated by NCA.

• Journal of Internet Computing and Services
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• v.7 no.2
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• pp.121-136
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• 2006

Software architecture and protocols to be maintained between components for the reconfigurable SDR system is analyzed and suggest system design idea for the implementation of software. To do this, related surveys are reviews and set up the system model with the structure of embedded system. SDR system architecture is suggested with five layered structure, consisted with hardware, operating system, middle-ware, service objects and application layer. SDR system is designed to be work on the basis of Linux operating system, and aimed to be scalable and reconfigurable. It is introduced the design result of software protocol and state transition diagram for the implementations of software download function which is the most important feature in SDR.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.39-48
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• 2016

One of the major trends of automotive networking architecture is the introduction of automotive Ethernet. Ethernet is already used in single automotive applications (e.g. to connect high-data-rate sources as video cameras), it is expected that the ongoing standardization at IEEE (IEEE802.3bw - 100BASE-T1, respectively IEEE P802.3bp - 1000BASE-T1) will lead to a much broader adoption in future. Those applications will not be limited to simple point-to-point connections, but may affect Electric/Electronic(EE) Architectures as a whole. It is agreed that IP based traffic via Ethernet could be secured by application of well-established IP security protocols (e.g., IPSec, TLS) combined with additional components like, e.g., automotive firewall or IDS. In the case of safety and real-time related applications on resource constraint devices, the IP based communication is not the favorite option to be used with complicated and performance demanding TLS or IPSec. Those applications will be foreseeable incorporate Layer-2 based communication protocols as, e.g., currently standardized at IEEE[13]. The present paper reflects the state-of-the-art communication concepts with respect to security and identifies architectural challenges and potential solutions for future Ethernet Switch-based EE-Architectures. It also gives an overview and provide insights into the ongoing security relevant standardization activities concerning automotive Ethernet. Furthermore, the properties of non-automotive Ethernet security mechanisms as, e.g., IEEE 802.1AE aka. MACsec or 802.1X Port-based Network Access Control, will be evaluated and the applicability for automotive applications will be assessed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.8
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• pp.974-985
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• 2016

Riverbed Modeler, which is a commercial packet-level discrete event simulator is used to model, design, and simulate complicated communication protocols and large-scale network. Riverbed Modeler got credit for its reliability in field of network simulation. In the MANET simulation environment using Riverbed Modeler, it is very complicated to add a new routing protocol into existing architecture of routing protocols because it is required lots of modifications of protocol recognition. In this paper, we propose Routing Adding Framework which can reduce errors or mistakes during modifying the existing routing support architecture. Routing Adding Framework is provided as a adapter API for protocol recognition. and it is only minimum modifications for protocol identifiers when a new routing protocol is added to the child process of manet_mgr process which manages routing protocols for IP layer. With Routing Adding Framework, we can reduce less than half modification. Then, we shows an example of implementation of a hybrid routing protocol AntHocNet using Routing Adding Framework, and we verify its design and application of the Routing Adding Framework by obtaining simulation result with similar result given by AntHocNet.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.481-504
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• 2010

Wireless smart sensor networks (WSSNs) have been proposed by a number of researchers to evaluate the current condition of civil infrastructure, offering improved understanding of dynamic response through dense instrumentation. As focus moves from laboratory testing to full-scale implementation, the need for multi-hop communication to address issues associated with the large size of civil infrastructure and their limited radio power has become apparent. Multi-hop communication protocols allow sensors to cooperate to reliably deliver data between nodes outside of direct communication range. However, application specific requirements, such as high sampling rates, vast amounts of data to be collected, precise internodal synchronization, and reliable communication, are quite challenging to achieve with generic multi-hop communication protocols. This paper proposes two complementary reliable multi-hop communication solutions for monitoring of civil infrastructure. In the first approach, termed herein General Purpose Multi-hop (GPMH), the wide variety of communication patterns involved in structural health monitoring, particularly in decentralized implementations, are acknowledged to develop a flexible and adaptable any-to-any communication protocol. In the second approach, termed herein Single-Sink Multi-hop (SSMH), an efficient many-to-one protocol utilizing all available RF channels is designed to minimize the time required to collect the large amounts of data generated by dense arrays of sensor nodes. Both protocols adopt the Ad-hoc On-demand Distance Vector (AODV) routing protocol, which provides any-to-any routing and multi-cast capability, and supports a broad range of communication patterns. The proposed implementations refine the routing metric by considering the stability of links, exclude functionality unnecessary in mostly-static WSSNs, and integrate a reliable communication layer with the AODV protocol. These customizations have resulted in robust realizations of multi-hop reliable communication that meet the demands of structural health monitoring.

• Journal of Intelligence and Information Systems
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• v.9 no.1
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• pp.211-225
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• 2003

This paper aims at the design of collaborative architecture for business to business (B2B) applications based on Web service protocol. As different business processes should be interfaced in the B2B environment collaboration is important fur the success of B2B implementation. For the development tools, XML, Web services and ASP.NET were adopted Web services are emerging to provide a systematic and extensible framework for application-to-application interaction. The Web services framework is divided into three areas; communication protocols, service descriptions and Web discovery. Web services such as SOAP, WSDL and UDDI correspond to the three areas respectively. ASP.NET is utilized which corresponds to the component and service set located in the top layer of .NET. For the service of product category and product details, Web service architecture was implemented based upon the SQL server database.

• Journal of KIISE:Information Networking
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• v.32 no.5
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• pp.593-602
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• 2005

Overlay multicast delivery method is a new approach in which multicast functionality is implemented at the end-hosts application layer in the timing of sparse deployment of IP multicast. However, existing overlay multicast protocols are not being standardization and many restrictions occur when delivering high capacity contents. Therefore, new delivery mechanism is required for the overlay multicast based high capacity contents delivery. In this paper. we separate group management and delivery management of overlay multicast and describe a capable group management. We also defined high speed delivery method better than that of existing overlay multicast through use of collaborated distribute downloading. This improved efficiency of massive contents transmission.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.12
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• pp.2347-2356
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• 2017

Raspberry Pi has been widely used for a hardware platform to develop the Internet of Things (IoT) applications. The basic task of diverse IoT devices is to obtain their status or environmental information by using various sensors and to send them to a gateway or a remote server. For the purpose, one of application layer protocols for IoT, MQTT is widely used. IoT devices are often powered by batteries and they are required to operate for a long time without replacing or recharging their batteries. Thus, energy efficiency is one of the most critical problems for obtaining and sending sensor data. To develop energy-efficient IoT applications, the information about power consumption characteristics of the applications is necessary. However, there has been little study to analyze power consumption of IoT communication on IoT devices. This paper presents a study to measure and analyze the power consumption of sending/receiving data under various conditions via the MQTT protocol on Raspberry Pi.