• Title/Summary/Keyword: packet data

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The Adaptive Multimedia Contents Service Method to Reduce Delay of MN in HMIPv6 (HMIPv6에서 MN의 지연을 최소화하는 멀티미디어 컨텐츠 서비스 방법)

  • Park, Won-Gil;Kang, Eui-Sun
    • The KIPS Transactions:PartB
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    • v.15B no.6
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    • pp.585-594
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    • 2008
  • The issues that we should consider in the process of providing mobile web service using a mobile device are seamless service and QoS-guaranteed service. HMIPv6 has MAP because of improving packet loss and transmission delay due to disconnection. However, a load is concentrated on HMIPv6 because of receiving and delivering packet for MN. Owing to this, real time data fails to be processed quickly, and also adaptive mobile service is required for QoS guaranteed service. However, this method demands the response time cost of contents service owing to the hardware differences of various devices. Therefore, we improve the process performance of real time data by applying a queue in MAP for seamless service in this paper. For decreasing response time cost, we propose mobile web service method which has reusable cache of contents using the elements of contents. The result of a numerical formula and simulation shows that our proposed method is superior under various system conditions.

Design of a Request Pattern based Video Proxy Server Management Technique for an Internet Streaming Service (인터넷 스트리밍 서비스를 위한 요청 기반 비디오 프록시 서버 관리 기법의 설계)

  • Lee, Jun-Pyo;Cho, Chul-Young;Lee, Jong-Soon;Kim, Tae-Yeong;Kwon, Cheol-Hee
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.6
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    • pp.57-64
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    • 2010
  • Due to the limited storage space in video proxy server, it is often required to replace the old video data which is not serviced for long time with the newly requested video. This replacement causes the service delay and increase of network traffic. To circumvent this problem, we propose the an efficient replacement scheme in a video proxy server. In addition, we present a video data management technique for decreasing the number of replacement in video proxy server. For this purpose, we employ a memory in video proxy server. If the video segment which is loaded in memory is requested once again by a different user, this segment is resided in memory. The video in the memory is stored in the video proxy server depending on the consuming pattern by users. The simulation results show that the proposed algorithm performs better than other algorithms in terms of packet hit rate and number of packet replacement.

An Efficient Scheduling Scheme for Bluetooth Piconets (블루투스 피코넷을 위한 효율적 스케줄링 기법)

  • 이우신;이혁준
    • Journal of KIISE:Information Networking
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    • v.30 no.1
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    • pp.38-47
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    • 2003
  • Communication between Bluetooth devices is based on TDD by a master unit. In this discipline, the transmission of slave packets can be made only when the master transmits a packet to the slave. Thus, some slots may be wasted when there is no user data in the master's or slave's queue due to the transmission of a POLL or NULL packet. Therefore a scheduling scheme which can minimize the slot waste is required in Bluetooth intra-piconet communication. However, since the master is responsible for the intra-piconet scheduling, it must be provided with an information on each slave's queue length to apply traditional scheduling schemes. which is impossible in Bluetooth. This paper presents a new Bluetooth intra-piconet scheduling scheme that is efficient and does not require the information on each slave's queue length. The scheduling is done based on the information about the existence of data in the master and slave queues which is derived by the master identifying the type of packets transmitted. The master schedules to communicate with the slaves according to the priorities determined based on this information. We Presents simulation results which indicate a significant improvement in the performance when our proposed scheme is used.

Efficient Channel Estimation and Packet Scheduling Scheme for DVB-S2 ACM Systems (DVB-S2 ACM 시스템을 위한 효율적인 채널 예측 및 패킷 스케줄링 기법)

  • Kang, Dong-Bae;Park, Man-Kyu;Chang, Dae-Ig;Oh, Deock-Gil
    • Journal of Satellite, Information and Communications
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    • v.7 no.1
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    • pp.65-74
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    • 2012
  • The QoS guarantee for the forward link in satellite communication networks is very important because there are a variety of packets with multiplexing. Especially, the packets are processed depending on the available bandwidth in satellite network changing the wireless channel state in accordance with weather condition. The DVB-S2 increases the transmission efficiency by applying the adaptive coding and modulation (ACM) techniques as a countermeasure of rain attenuations. However, the channel estimation algorithm is required to support the ACM techniques that select the MODCOD values depending on the feedback data transmitted by RCSTs(Return Channel via Satellite Terminal) because satellite communication networks have a long propagation delay. In this paper, we proposed the channel estimation algorithm using rain attenuation values and reference data and the packet scheduling scheme to support the QoS and fairness. As a result of performance evaluation, we showed that proposed algorithm exactly predicts the channel conditions and supports bandwidth fairness to the individual RCST and guarantees QoS for user traffics.

A Low-Delay MAC(LD-MAC) protocol in Multi-Hop Wireless Sensor Networks (멀티 홉 무선 센서 네트워크에서 저 지연을 지원하는 MAC 프로토콜)

  • Jeon, Jun-Heon;Kim, Seong-Cheol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.2
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    • pp.452-458
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    • 2014
  • In Wireless Sensor Networks the Medium access control (MAC) protocol has many challenges to solve such as reducing energy consumption, supporting QoS(quality of service) fairness, and reducing delivery delay. This paper proposed a low-delay supporting MAC protocol in multi-hop Wireless Sensor Networks. The proposed protocol uses the RB(rapid beacon) frame for reducing delivery delay. The RB frame is a modified IEEE 802.15.4 beacon frame. For sender adaptive-wakeup, the RB frame includes a seed number for determining of a receiver wakeup time. And for next hop receiver adaptive-wakeup, the RB frame includes the length of remaining data packet information. Results showed that our LD-MAC protocol outperformed other protocol in terms of data packet delivery delay.

Vulnerability Analysis of Bluetooth Communication based on GNU Radio (GNU Radio 기반 블루투스 통신 취약점 분석)

  • Kim, Tae-Yong;Lee, Hoon-Jae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.11
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    • pp.2014-2020
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    • 2016
  • In general, automatic access control management system using smart door-lock must be always exposed to security vulnerability during wireless communication based on Bluetooth. In particular, important information such as a secrete key can be exposed to the attacker when the authentication protocol has been operating in the wireless section. Therefore important information exchanged in the radio section needs to be properly encrypted. In order to analyze security vulnerability for automatic access control management system of public facilities such as subway vent, GNU Radio platform and HackRF device will be considered and experimented. Proposed experimental system to perform software based power analysis attack could be very effectively applied. As a result, important information such as packet type, CRC, length of data, and data value can be easily decoded from wireless packet obtained from HackRF device on GNU Radio platform. Constructed experimental system will be applied to avoid some security problems.

An Intelligent Bluetooth Intrusion Detection System for the Real Time Detection in Electric Vehicle Charging System (전기차 무선 충전 시스템에서 실시간 탐지를 위한 지능형 Bluetooth 침입 탐지 시스템 연구)

  • Yun, Young-Hoon;Kim, Dae-Woon;Choi, Jung-Ahn;Kang, Seung-Ho
    • Convergence Security Journal
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    • v.20 no.5
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    • pp.11-17
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    • 2020
  • With the increase in cases of using Bluetooth devices used in the electric vehicle charging systems, security issues are also raised. Although various technical efforts have beed made to enhance security of bluetooth technology, various attack methods exist. In this paper, we propose an intelligent Bluetooth intrusion detection system based on a well-known machine learning method, Hidden Markov Model, for the purpose of detecting intelligently representative Bluetooth attack methods. The proposed approach combines packet types of H4, which is bluetooth transport layer protocol, and the transport directions of the packet firstly to represent the behavior of current traffic, and uses the temporal deployment of these combined types as the final input features for detecting attacks in real time as well as accurate detection. We construct the experimental environment for the data acquisition and analysis the performance of the proposed system against obtained data set.

A Study on Mid-amble based V2X Channel Estimation Techniques Using Bidirectional Averaging (양방향 평균화를 이용한 새로운 Mid-amble 기반 V2X 채널추정 기법에 관한 연구)

  • Kim, Ju-Hyeok;Song, Changick
    • Journal of IKEEE
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    • v.26 no.2
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    • pp.287-291
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    • 2022
  • In general, as the amplitude and phase information of the physical layer channel impulse response change rapidly in time and frequency according to the high-speed movement of the vehicles in V2X communication systems, it is difficult to accurately estimate these channels at the receiving end. In order to effectively overcome this problem, midamble-based channel estimation methods in which mid-ambles are periodically inserted into a packet have been recently considered. However, as the number of midambles increases, we suffer from the spectral efficiency loss. To relieve such a loss, in this paper, we propose a new bidirectional averaging channel estimation method that combines the existing data pilot-based channel estimation methods and the mid-ambles. Finally, through the simulation results, we demonstrate that the proposed method outperforms the existing mid-amble method in terms of packet error rate with fewer number of mid-ambles.

Enhancing the Quality of Service by GBSO Splay Tree Routing Framework in Wireless Sensor Network

  • Majidha Fathima K. M.;M. Suganthi;N. Santhiyakumari
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.8
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    • pp.2188-2208
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    • 2023
  • Quality of Service (QoS) is a critical feature of Wireless Sensor Networks (WSNs) with routing algorithms. Data packets are moved between cluster heads with QoS using a number of energy-efficient routing techniques. However, sustaining high scalability while increasing the life of a WSN's networks scenario remains a challenging task. Thus, this research aims to develop an energy-balancing component that ensures equal energy consumption for all network sensors while offering flexible routing without congestion, even at peak hours. This research work proposes a Gravitational Blackhole Search Optimised splay tree routing framework. Based on the splay tree topology, the routing procedure is carried out by the suggested method using three distinct steps. Initially, the proposed GBSO decides the optimal route at initiation phases by choosing the root node with optimum energy in the splay tree. In the selection stage, the steps for energy update and trust update are completed by evaluating a novel reliance function utilising the Parent Reliance (PR) and Grand Parent Reliance (GPR). Finally, in the routing phase, using the fitness measure and the minimal distance, the GBSO algorithm determines the best route for data broadcast. The model results demonstrated the efficacy of the suggested technique with 99.52% packet delivery ratio, a minimum delay of 0.19 s, and a network lifetime of 1750 rounds with 200 nodes. Also, the comparative analysis ensured that the suggested algorithm surpasses the effectiveness of the existing algorithm in all aspects and guaranteed end-to-end delivery of packets.

A Study on the Performance Evaluation for the Integrated Voice/Data Transmission with FDDI (FDDI 음성/데이타 집적 전송에서의 성능 분석에 관한 연구)

  • 홍성식;박호균;이재광;류황빈
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.17 no.3
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    • pp.277-287
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    • 1992
  • In this paper, we study the performance eualuations of the FDDI Network, by mathmeticlal analysis and simulation, in which the Integrated Voice/Data transmission system with voice traffic in synchronous mode and data traffic inasynchronous mode.For the mean waiting times of Voice/Data packet, we use two-state of Marcov models for voice traffic with talkspurt and silenci state, and the data traffic would traffic would transmit at the silence state of voice traffic. By the mean wating times, we analyze the relations between synchronous and asynchronous mode. As a result, using Sync/Async mode with voice and data, voice was not under influnece of data traffic. and in the same time,data can be tanaxmitted in a short waiting time, too.

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