• Title/Summary/Keyword: Protocol Data Unit

Search Result 164, Processing Time 0.03 seconds

New Retransmission Method using the minimum MPDU starting Spacing in Two-level Aggregation of IEEE 802.11n (IEEE 802.11n의 2-레벨 집적 방식에서 최소 MPDU 시작 간격을 이용하는 새로운 재전송 방법)

  • Shin, In Cheol;Kim, Dong-Hoi
    • Journal of Broadcast Engineering
    • /
    • v.20 no.2
    • /
    • pp.300-309
    • /
    • 2015
  • In IEEE 802.11n WLANs(Wireless Local Area Networks), to support high throughput, MAC(Media Access Control) layer adopts A-MSDU(Aggregate-MAC Service Data Unit) and A-MPDU(Aggregate-MAC Protocol Data Unit). Generally, as the A-MPDU uses a selective retransmission capability, A-MPDU provides higher throughput than A-MSDU. However, although A-MPDU uses the selective re-transmission capability, if the size of MPDU within A-MPDU is smaller than the size of minimum MPDU starting spacing, A-MPDU can reduce throughput because of the overhead of retransmission owing to the addition of delimiter, that is a dummy MPDU. Therefore, to overcome the above problem, two-level Aggregation method, where the small MPDU within A-MPDU is replaced by not delimiter but A-MSDU, has been introduced. In the two-level Aggregation method, the existing re-transmission scheme retransmits only A-MPDU, but if the size of retransmission data is smaller than the size of the minimum MPDU starting spacing, the proposed retransmission scheme retransmits the aggregated retransmission data and MSDUs. Therefore, we know that the proposed retransmission scheme have better throughput that the existing retransmission scheme.

Intrabed and Interbed Networks for Patient Monitoring (환자 모니터링을 위한 인트라베드 및 인터베드 통신망)

  • Park, Seung-Hun;Woo, Eung-Je;Kim, Kyung-Soo;Choi, Keun-Ho;Kim, Seung-Tae;Lee, Hee-Cheol;Seo, Jae-Joon;Kim, Hyung-Jin
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1997 no.05
    • /
    • pp.285-289
    • /
    • 1997
  • In this paper, we describe the intrabed and interbed network in a developed patient monitoring system. Intrabed network handles data communication among the main unit of a bedside monitor and parameter modules plugged in it. Interbed network deals with a higher level data communication among many bedside monitors, central stations, DB servers, and clinical workstations. Analyzing the data communication requirements in each stage of the system, we designed the intrabed network based upon RS-485 and HDLC protocol with 1Mbps data rate. Interbed network is designed to utilize the industry standard 10Base-T Ethernet with TCP/IP and UDP protocol. We present the specifications and the performances of the developed data communication networks in the patient monitoring system.

  • PDF

Remote Measurement of the Automobile′s ECU Signals with KWP2000 using Bluetooth Module (Bluetooth 모듈을 이용한 KWP2000 차량 ECU신호의 원격 계측)

  • Choi Kwang-Hun;Kwon Tae-Kyu;Lee Seong-Cheol
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.21 no.10
    • /
    • pp.86-93
    • /
    • 2004
  • This paper presents the remote measurement of the ECU signals adopted with KWP 2000 protocol using the wireless communication technique of bluetooth. The bluetooth technology will be the most promising network paradigm which can open the new area in the information technology. Especially, bluetooth module is able to link all the electrical products and personal computers to cellular phone or PDA. This research has a try to design a wireless measurement model of ECU signal based on the car telemery system using bluetooth device. In order to measure the ECU signals, we designed the interface circuits which is able to communicate between the ECU system and the terminal circuits according to the ISO, SAE regulation of communication protocol standard. A microprocessor S3c341 OX is used for the system control and communication of ECU signals. The embedded system software is programmed to measure the ECU signals using the ARM compiler and ANCI C based on Micro/OS-II kernel to communicate between two bluetooth modules using bluetooth stack. The remote measurement of ECU signals using the bluetooth was designed and implemented to evaluate the performance of wireless network to the transmit measurement data. The possibility for the remote measurement of the self diagnosis signals of ECU adopted with KWP2000 protocol verified through the developed systems and algorithms in embedded system.

Effects of an Information Protocol on Anxiety and Nursing Satisfaction for Family Caregivers of Cerebrovascular Accident Patients in the ICU (정보제공이 중환자실에 입원한 뇌졸중환자 가족의 불안 및 간호만족도에 미치는 영향)

  • Cho, Kyung-Jin;Jun, Eun-Mi
    • Journal of Korean Academy of Fundamentals of Nursing
    • /
    • v.14 no.1
    • /
    • pp.53-61
    • /
    • 2007
  • Purpose: The purpose of this study was to investigate the effects of an information protocol for anxiety and nursing satisfaction of family caregivers. The caregivers were caring for a family member who had a CVA (cerebrovascular accident) and who had been admitted to the ICU (intensive care unit). Method: The research design was a non-equivalent control group non-synchronized design. Data were collected from April 1 to October 31, 2005 at D hospital in Busan City The participants were 40 family caregivers of patients with a CVA admitted to the ICU. Caregivers in the experimental group participated in the information protocol for 30 min. Both groups were pre-tested before the intervention for two variables, anxiety and nursing needs. The post-test of both groups included anxiety and nursing satisfaction. The instruments used in this study were the Spielberger's state anxiety inventory (1976) and the nursing satisfaction scale developed by Molter (1979). Results: Anxiety scores were significantly lower and nursing satisfaction scores were significantly higher for caregivers in the experimental group compared to those in the control group. Conclusion: The information protocol was effective in reducing anxiety and increasing the level of nursing satisfaction of family caregivers caring for an ICU patients with a CVA.

  • PDF

A Handover Protocol for the IEEE WAVE-based Wireless Networks (IEEE WAVE 기반의 무선 네트워크를 위한 핸드오버 프로토콜)

  • Choi, Jung-Wook;Lee, Hyuk-Joon;Choi, Yong-Hoon;Chung, Young-Uk
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.10 no.1
    • /
    • pp.76-83
    • /
    • 2011
  • The IEEE WAVE-based communication systems do not provide handover services since most of the application layer messages of a small amount containing text data that are related to safe driving. Multimedia data service such as web pages and CCTV video clips, however, require a seamless handover for continuation of a session via multiple RSUs. In this paper, we propose a new proactive handover protocol based on IEEE WAVE. According to the proposed handover protocol, the OBU notifies the old RSU of its departure from the coverage such that the old RSU forwards to the new RSU the data heading towards the OBU to be cached for the further delivery upon its entry into the new RSU's coverage. The simulation results are presented which shows the performance of the proposed protocol in terms of throughput, delivery ratio and handover delay.

Analyzing of connected car vulnerability and Design of Security System (커네티트 카의 취약점 분석 및 보안 시스템 설계)

  • Kim, Tae-Hyoung;Jang, Jong-Wook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2016.05a
    • /
    • pp.241-243
    • /
    • 2016
  • In the Past, Trend of car security was Physical Something like doorlock system, and The Generation did not have skills connecting External devices. Through Car Development is up, that trend of car security Changed Physical Security to Intelligence Security. This Changes give a chance to hackers to attack this system. This System use CAN(Controller Area Network) Protocol which have three vulnerabilities. First, ID Spoofing, Twice, D - Dos Attack, Third, Android Application Injected Modern cars have many ECU(Electronic Control Unit) to control devices like Engine ON/OFF, Door Lock Handling, and Controlling Handle. Because CAN Protocol spread signal using broadcast, Hackers can get the signal very easily, and Those often use Mobile devices like Android or IOS to attack this system. if bluetooth signal is spread wide, hackers get the signal, and analysis the bluetooth data, so then They makes certain data to attack ECU, they send the data to ECU, and control ECU installed car. so I suggest that I will prevent this attack to make Auth system and prevent this attack in end of Android.

  • PDF

Telephone Inquiries to the Ophthalmology Nursing Unit and Nursing Interventions Through Telephone Consultations (3차 종합병원 안과병동의 전화 상담 중 전화문의 내용 및 간호중재에 대한 조사 연구)

  • Lee, Hyun-Jung;Park, Hyeoun-Ae
    • Journal of East-West Nursing Research
    • /
    • v.15 no.2
    • /
    • pp.157-167
    • /
    • 2009
  • Purpose: This study examines the patient problems and nursing interventions during telephone consultations by nurses in an ophthalmology nursing unit. Methods: The data were collected during telephone consultations. A total of 13 nurses consulted 170 patients between September 29 and November 30, 2008 at a tertiary teaching hospital. Problems were raised by the patients and nursing interventions were provided to the patients by the nurses. The SPSS program was used to analyze the data. Results: There were 228 telephone inquiries by 170 patients. The problems were categorized into four groups based on a literature review and validated by 14 nurses: physical symptoms, medications, administrative matters, and follow-up care. Interventions provided by the nurses were categorized into six groups: instructing patients; providing information; providing background knowledge; assuring the patients; referring to the patients to other ancillary departments; and delivering doctor's orders. Conclusions: Nurse interventions for a specific patient problem varied depending on the nurse providing the consultation. The participating nurses expressed the need for a common protocol for telephone consultations. Thus, it would be beneficial to develop a guideline for telephone consultations to minimize practice variations among nurses.

A Study on the development of automatic control programming for projection machine (사출기의 자동제어 프로그램 개발에 관한 연구)

  • 김현기;홍용인;이천희
    • Proceedings of the IEEK Conference
    • /
    • 1999.11a
    • /
    • pp.1145-1148
    • /
    • 1999
  • In this paper we developed the communication protocol in which can transmitter receive a data and instruction in pressure and control computer. This system can dramatically increase production by maximize by control the error in central unit and monitoring. When developed these pressure automatic control system, it can be automation product in factory and decrease man-power.

  • PDF

TID providing method for IEEE 802.l1e MAC protocol in NCTUns simulator (NCTUns 시뮬레이터에서 IEEE 802.11e MAC 프로토콜을 위한 TID 제공방안)

  • 김영환;허필영;석정봉
    • Proceedings of the IEEK Conference
    • /
    • 2003.11c
    • /
    • pp.212-215
    • /
    • 2003
  • 본 논문에서는 IEEE 802.11e MAC (Medium Access Control) 프로토콜을 NS-2 등과 같은 유명한 시뮬레이터들보다도 진보적인 NCTUns 시뮬레이터를 이용하여 개발하고자 하면서, 각 MSDU (MAC Service Data Unit)마다 제공되어야 하는 TID (Traffic Identification) 를 결정하는 방안을 모색하고 있다. 따라서 본론에서는 IEEE 802.l1e MAC 프로토콜과 NCTUns 시뮬레이터 에 대해서 기술하며 본 논문에서 제안하는 방법에 대해서 서술한다.

  • PDF

A Study of Vehicle's Monitoring and Controller Using Imbedded Web Server (임베디드 웹 서버를 이용한 자동차용 모니터링 및 제어기 개발에 관한 연구)

  • Lee, Suk-Won;Yang, Seung-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.19 no.2
    • /
    • pp.107-113
    • /
    • 2005
  • In this paper, Web server is built up using PXA255, 32bit RISC processor with porting Embedded Linux and GoAhead HTTP(Hyper Text Transfer Protocol) web server, and the system which can monitor and control the environment and condition for AICC(Automatic Intelligent Cruise Control) is realized For sensing the operation condition and change of vehicle the desired data is derived by interfacing ECU(Electric Control Unit) and Embedded system and the rpm of engine is controlled by step motor connected to throttle valve.