• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.1
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• pp.39-45
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• 2008

High-Rate Wireless Personal Area Networks (HR-WPANs) in IEEE 802.15.3 standard use a TIme Devision Multiple Access (TDMA) protocol to support isochronous traffic. Isochronous traffic requires a delay-bounded service. However, the HR-WPAN standard suffers from long access delay and association delay. In this paper, we propose an enhanced MAC protocol for the delay-bounded traffic. This proposed protocol provides a way that a central node is able to collect traffic status on all member nodes. Furthermore, by utilizing the information, a scheduling algorithm is also proposed in order to synchronize the instant of a packet transmission with that of the packet arrival. With the proposed protocol and algorithm, the delay of access and association can be reduced. Performance analysis is carried out and the significant performance enhancement is observed.

• The Journal of Society for e-Business Studies
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• v.13 no.2
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• pp.195-212
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• 2008

The demand of wireless communication system is increasing due to the development of computers and other digital media appliances. In particular, new wireless communication technology is necessary for implementation of home network since a lot of data transmission is occurred. Recently, two wireless communication technologies, Ultra Wide Band(UWB) and 60GHz band wireless communication technology, have being developed for high-speed data transmission and Wireless Personal Area Network(WPAN). In this paper, we study the present development condition of these two technologies and a role of them in home network. We also suggest the method to implement the home network using all wireless communication technologies. At the end, we outlook the market of WPAN and High Definition Multimedia Interface(HDMI).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.1
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• pp.88-91
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• 2016

In this paper, we have proposed the frequency interference analysis system using both LabVIEW and Universal Software Radio Peripheral(USRP) for performance degradation analysis of Multi Input Multi Output-Orthogonal Frequency Division Multiplexing(MIMO-OFDM) Wireless Local Area Network(WLAN) due to Wireless Local Area Network(WPAN) interferer. The proposed system consists of three part, i.e., victim, channel, and interferer. Both victim and interferer are implemented by LaBVIEW and a USRP board. Then interfering signal and additive white Gaussian noise are combined with the wanted signals of a victim. Measured Bit Error Rate(BER) at the victim receiver is compared with theoretical BER according to various signal to interference plus noise power ratio (SINR) values. Measured and theoretical BER curves show good agreement.

• IEMEK Journal of Embedded Systems and Applications
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• v.2 no.1
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• pp.43-52
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• 2007

IEEE 802.15.4 specification which defines low-rate wireless personal area network(LR-WPAN) has application to home or building automation, remote control and sensing, intelligent management, environmental monitoring, and so on. Recently, it has been considered as an alternative technology to provide multimedia services such as automation via voice recognition, wireless headset and wireless camera for surveillance. In order to evaluate capability of voice traffic on the IEEE 802.15.4 LR-WPAN, we supposed two scenarios, voice traffic only and coexistence of voice and sensing traffic. For both cases we examined delay and packet loss rate in case of with and without acknowledgement, and various beacon period varying with beacon and superframe order values. In LR-WPAN with voice devices only, total 5 voice devices could be applicable and in the other case, i.e., coexisted cases of voice and sensor devices, a voice device was able to coexist with about 60 sensor devices.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9B
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• pp.1305-1313
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• 2010

Last few years, wireless personal area network (WPAN) has been widely researched for various healthcare applications. Due to restriction of device hardware (e.g., energy and memory), we need to design a highly-versatile MAC layer protocol for WBAN (Wireless Body Area Network). In addition, when an emergency occurs to a patient, a priority mechanism is necessitated for a urgent message to get through to the final destination. This paper presents a priority mechanism referred to as hybrid priority MAC for WBAN. Through extensive simulation, we show the proposed MAC protocol can minimize the average packet latency for urgent data. Thus, when patients have an emergency situation, our MAC allows adequate assistance time and medical treatment for patients. The simulation based on NS-2 shows that our Hybrid Priority MAC has the good performance and usability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7B
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• pp.583-594
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• 2006

WPANs (Wireless personal area networks) have developed as various forms according to requirements such as data rate, coverage, subscriber volume, and supported mobile velocity. And mobile device with multiple network interfaces is very common. To make these multi-mode devices communicate with any WPAN device at anytime, anywhere, the framework for heterogeneous wireless networks is essential. Therefore, we propose the integration framework to converge heterogeneous WPANs. In this paper, we explain the requirements and detailed design of our framework, and then present the emulation test results.

• ETRI Journal
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• v.28 no.4
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• pp.537-540
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• 2006

When multiple ZigBee wireless personal area networks (WPANs) are in close proximity to each other, contentions and collisions in transmissions will lead to increased packet delays. However, there is no existing study on how delay performance would be affected in a crowded real-life environment where each person walking down a busy street would be wearing a ZigBee WPAN. This letter studies the use of ZigBee WPANs in such a real-life environment for real-time heart beat monitoring. To be pragmatic, we derived a mobility pattern from the analysis of a real-life video trace. Then, we estimated the delay performance from the video trace by combining data collected from ZigBee experiments. The results show that the 300 ms packet delay requirement will not be met for only 11% of the time. When failure occurs, it will last for an average duration of 1.4 s.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3B
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• pp.135-143
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• 2008

In this paper, we propose a QoS guaranteed and energy-efficient transmission scheme for Wireless Personal Area Networks (WPANs), which operate in conjunction with contention-based access protocols such as CSMA/CA. Energy consumption is one of the most important issues in WPAN systems, because WPAN devices are often required to operate under limited battery capacity. Furthermore, if the WPAN adopts a contention-based medium access protocol, the energy consumption problem becomes even more critical due to the collisions caused by independent channel access trials. Therefore, in this paper, we propose an algorithm that selects the optimum fragment size, modulation level, and transmission power, in order to minimize the energy consumption and guaranteethe QoS (Quality of Service) requirements, simultaneously. Our simulation results show that the proposed algorithm has better performance than the previous ones.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.6
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• pp.1128-1133
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• 2008

Context-aware computing has been attracting the attention as an approach to alleviating the inconvenience in human-computer interactions. This paper proposes a context-aware system architecture to be implemented on an UoC (Ubiquitous system on Chip). A new proposed technology of CRS (Context Recognition Switch) and DOS (Dynamic and Optimal Standard) based on Context-awareness system architecture with pre-processor, HPSP(High Performance Signal Processor) in this paper. And proposed a new algorithm using in network topology processor shows for Ubiquitous Computing System. implementing in UoC (Ubiquitous System on Chip) base on the IEEE 802.15.4 WPAN (Wireless Personal Area Network) standard. Also, This context-aware based UoC architecture has been developed to apply to mobile intelligent robots which would support human in a context-aware manner.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.5
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• pp.407-412
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• 2014

Concerns and demands for the Location Based Services (LBS) using Global Positioning System (GPS) and Wi-Fi are largely increased in the world in the present. In some experimental results, it was noted that many errors are frequently occurred when the distances between an anchor node and a mobile node acre measured in indoor localization environment of Wireless Personal Area Network (WPAN). In this paper, localization compensation algorithm based on maximum measurement value ($LCA_{MMV}$) for moving objects in WPAN is proposed, and the performance of the algorithm is analyzed by experiments on three scenarios for movement of mobile nodes. From the experiments, it was confirmed that the average localization accuracy of suggested algorithm was more increased than Symmetric Double-Sided Two-Way Ranging (SDS-TWR) and triangulation as average 40.9cm, 77.6cm and 6.3cm, respectively on scenario 1-3.